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Sample records for non-methane organic gas

  1. 40 CFR 86.1710-99 - Fleet average non-methane organic gas exhaust emission standards for light-duty vehicles and...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Fleet average non-methane organic gas....1710-99 Fleet average non-methane organic gas exhaust emission standards for light-duty vehicles and... follows: Table R99-15—Fleet Average Non-Methane Organic Gas Standards (g/mi) for Light-Duty Vehicles...

  2. Multi-instrument comparison and compilation of non-methane organic gas emissions from biomass burning and implications for smoke-derived secondary organic aerosol precursors

    Science.gov (United States)

    Hatch, Lindsay E.; Yokelson, Robert J.; Stockwell, Chelsea E.; Veres, Patrick R.; Simpson, Isobel J.; Blake, Donald R.; Orlando, John J.; Barsanti, Kelley C.

    2017-01-01

    Multiple trace-gas instruments were deployed during the fourth Fire Lab at Missoula Experiment (FLAME-4), including the first application of proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOFMS) and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) for laboratory biomass burning (BB) measurements. Open-path Fourier transform infrared spectroscopy (OP-FTIR) was also deployed, as well as whole-air sampling (WAS) with one-dimensional gas chromatography-mass spectrometry (GC-MS) analysis. This combination of instruments provided an unprecedented level of detection and chemical speciation. The chemical composition and emission factors (EFs) determined by these four analytical techniques were compared for four representative fuels. The results demonstrate that the instruments are highly complementary, with each covering some unique and important ranges of compositional space, thus demonstrating the need for multi-instrument approaches to adequately characterize BB smoke emissions. Emission factors for overlapping compounds generally compared within experimental uncertainty, despite some outliers, including monoterpenes. Data from all measurements were synthesized into a single EF database that includes over 500 non-methane organic gases (NMOGs) to provide a comprehensive picture of speciated, gaseous BB emissions. The identified compounds were assessed as a function of volatility; 6-11 % of the total NMOG EF was associated with intermediate-volatility organic compounds (IVOCs). These atmospherically relevant compounds historically have been unresolved in BB smoke measurements and thus are largely missing from emission inventories. Additionally, the identified compounds were screened for published secondary organic aerosol (SOA) yields. Of the total reactive carbon (defined as EF scaled by the OH rate constant and carbon number of each compound) in the BB emissions, 55-77 % was associated with compounds for

  3. Non-methane volatile organic compound flux from a subarctic mire in Northern Sweden

    OpenAIRE

    Bäckstrand, Kristina; Crill, Patrick M.; Mastepanov, Mikhail; Christensen, Torben R.; Bastviken, David

    2011-01-01

    Biogenic NMVOCs are mainly formed by plants and microorganisms. They have strong impact on the local atmospheric chemistry when emitted to the atmosphere. The objective of this study was to determine if there are significant emissions of non-methane volatile organic compounds (NMVOCs) from a subarctic mire in northern Sweden. Subarctic peatlands in discontinuous permafrost regions are undergoing substantial environmental changes due to their high sensitivity to climate warming and there is ne...

  4. Speciation of Total Organic Gas and Particulate Matter Emissions from Onroad Vehicles in the Next Version of MOVES

    Science.gov (United States)

    Calculation of organic gas measures used in MOVES (total hydrocarbons, methane, non-methane hydrocarbons, volatile organic compounds, non-methane organic gases, and total organic gases). Incorporation of speciation within MOVES to produce total organic gas and particulate matte...

  5. Non-methane volatile organic compounds in Africa: A view from space

    Science.gov (United States)

    Marais, Eloise Ann

    Isoprene emissions affect human health, air quality, and the oxidative capacity of the atmosphere. Globally anthropogenic non-methane volatile organic compounds (NMVOC) emissions are lower than that of isoprene, but local hotspots are hazardous to human health and air quality. In Africa the tropics are a large source of isoprene, while Nigeria appears as a large contributor to regional anthropogenic NMVOC emissions. I make extensive use of space-based formaldehyde (HCHO) observations from the Ozone Monitoring Instrument (OMI) and the chemical transport model (CTM) GEOS-Chem to estimate and examine seasonality of isoprene emissions across Africa, and identify sources and air quality consequences of anthropogenic NMVOC emissions in Nigeria. To estimate isoprene emissions I first developed a filtering scheme to remove (1) contamination from biomass burning and anthropogenic influences; and (2) displacement of HCHO from the isoprene emission source diagnosed with the GEOS-Chem CTM. Conversion to isoprene emissions is with NOx-dependent GEOS-Chem HCHO yields, obtained as the local sensitivity S of the HCHO column ΩHCHO to a perturbation Delta in isoprene emissions EISOP (S = DeltaΩHCHO/DeltaE ISOP). The error in OMI-derived isoprene emissions is 40% at low levels of NOx and 40-90% under high-NOx conditions and is reduced by spatial and temporal averaging to the extent that errors are random. Weak isoprene emission seasonality in equatorial forests is driven predominantly by temperature, while large seasonality in northern and southern savannas is driven by temperature and leaf area index. The largest contribution of African isoprene emissions to surface ozone and particulate matter, determined with GEOS-Chem, of 8 ppbv and 1.5 μg m-3, respectively, is over West Africa. The OMI HCHO data feature a large enhancement over Nigeria that is due to anthropogenic NMVOC emissions. With the OMI HCHO data, coincident satellite observations of atmospheric composition, aircraft

  6. Characterizing non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation

    Science.gov (United States)

    Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

    2012-02-01

    Emissions of non-methane volatile organic compounds (NMVOCs) were determined from a swine concentrated animal feeding operation (CAFO) in North Carolina. NMVOCs were measured in air samples collected in SUMMA and fused-silica lined (FSL) canisters and were analyzed using a gas chromatography flame ionization detection (GC-FID) system. Measurements were made from both an anaerobic lagoon and barn in each of the four seasonal sampling periods during the period June 2007 through April 2008. In each sampling period, nine to eleven canister samples were taken from both the anaerobic lagoon and barn over a minimum of four different days during a period of ˜1 week. Measurements of meteorological and physiochemical parameters were also made during the sampling period. In lagoon samples, six NMVOCs were identified that had significantly larger emissions in comparison to other NMVOCs. This included three alcohols (ethanol, 2-ethyl-1-hexanol, and methanol), two ketones (acetone and methyl ethyl ketone (MEK)) and an aldehyde (acetaldehyde). The overall average fluxes for these NMVOCs, ranged from 0.18 μg m -2 min -1 for 2-ethyl-1-hexanol to 2.11 μg m -2 min -1 for acetone, with seasonal fluxes highest in the summer for four (acetone, acetaldehyde, 2-ethyl-1-hexanol and MEK) of the six compounds In barn samples, there were six NMVOCs that had significantly larger concentrations and emissions in comparison to other NMVOCs. These consisted of two alcohols (methanol and ethanol), an aldehyde (acetaldehyde), two ketones (acetone and 2,3-butanedione), and a phenol (4-methylphenol). Overall average barn concentration ranged from 2.87 ppb for 4-methylphenol to 16.12 ppb for ethanol. Overall average normalized barn emission rates ranged from 0.10 g day -1 AU -1 (1 AU (animal unit) = 500 kg of live animal weight) for acetaldehyde to 0.45 g day -1 AU -1 for ethanol. The NMVOCs, 4-methylphenol and 2,3-butanedione, which have low odor thresholds (odor thresholds = 1.86 ppb and 0

  7. Non-methane volatile organic compound flux from a subarctic mire in Northern Sweden

    Science.gov (United States)

    Bäckstrand, Kristina; Crill, Patrick M.; Mastepanov, Mikhail; Christensen, Torben R.; Bastviken, David

    2008-04-01

    Biogenic NMVOCs are mainly formed by plants and microorganisms. They have strong impact on the local atmospheric chemistry when emitted to the atmosphere. The objective of this study was to determine if there are significant emissions of non-methane volatile organic compounds (NMVOCs) from a subarctic mire in northern Sweden. Subarctic peatlands in discontinuous permafrost regions are undergoing substantial environmental changes due to their high sensitivity to climate warming and there is need for including NMVOCs in the overall carbon budget. Automatic and manual chamber measurements were used to estimate NMVOC fluxes from three dominating subhabitats on the mire during three growing seasons. Emission rates varied and were related to plant species distribution and seasonal net ecosystem exchange of carbon dioxide. The highest fluxes were observed from wetter sites dominated by Eriophorum and Sphagnum spp. Total NMVOC emissions from the mire (~17 ha) is estimated to consist of ~150 kgC during a growing season with 150 d. NMVOC fluxes can account for ~5% of total net carbon exchange (-3177 kgC) at the mire during the same period. NMVOC emissions are therefore a significant component in a local carbon budget for peatlands.

  8. Emissions of non-methane organic compounds from a grassland site

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Yoshiko; Doskey, P.V.

    1996-03-01

    A mixture of oxygenated hydrocarbons (OxHCs), isoprene, and monoterpenes was detected in the emissions from a grassland site in the Midwestern United States. A plot dominated by crown vetch (Coronilla varia) and bluegrass (Poa spp.), exhibited a constant decrease in emissions of total non-methane organic compounds (NMOCs) from 580 {mu}g m{sup -2} hr{sup -1} in June 1992 to 150 {mu}g m{sup - 2} hr{sup -1} in October 1992, except for a slight increase in August. Oxygenated hydrocarbons (methanol, acetaldehyde, and acetone) and terpenes (isoprene, limonene, myrcene, {alpha}-pinene, and {beta}- pinene) composed about 90% and 10% of the identified NMOC emissions, respectively. Isoprene represented about 10% of the terpene emissions. Total NMOC emission rates based on vegetative biomass averaged 2.3 {mu}g g{sup -1} hr{sup -1}, with 10% of the identified NMOCs attributed to monoterpenes and the remainder mainly OxHCs. Over the course of the investigation, the relationship between the monoterpene emission rate and the temperature for a single plot was logarithmic and similar to the one between compound vapor pressure and temperature. However, emission rates normalized to temperature decreased throughout the summer and fall, indicating that parameterizations of emission rates from herbaceous plants must include a factor to compensate for environmental conditions such as soil moisture and nutrient deposition, which affect plant phenology and the seasonal pattern of species dominance.

  9. Total non-methane volatile organic compounds (TNMVOC) in the atmosphere of Delhi

    Science.gov (United States)

    Kumar Padhy, Pratap; Varshney, C. K.

    Volatile organic compounds (VOC), more specifically, non-methane volatile organic compounds (NMVOC) play a critical role in the atmospheric chemistry. NMVOC, through complex photochemical reactions, contribute to the formation of toxic oxidants, such as tropospheric ozone and PAN, which are injurious to health and highly phytotoxic. Certain NMVOC have been shown to be highly toxic, mutagenic and carcinogenic. NMVOC are receiving increasing attention in the west on account of their implication for human health and air quality. On the other hand, information on NMVOC in India and other developing countries is not available. As a result, appreciation of potential threat from NMVOC in relation to air quality and public health is sadly lacking among planners and policy makers. The paper deals with the estimation of total NMVOC at 13 sites in the urban environment of Delhi during November 1994 to June 1995. An inexpensive, labour intensive manual sample collection device was used and the air samples were analysed using GC-FID. The results show that the amount of NMVOC in the ambient environment of Delhi varied between 1.3 and 32.5 ppmv exhibiting wide temporal and seasonal variation. NMVOC levels mostly peaked at 0900 h, which coincide with the peak traffic hour. The implications of NMVOC build-up in the urban atmosphere are obvious for air quality. The results of this preliminary study make out a strong case for developing a regular monitoring programme for NMVOC in the urban environment of Delhi as well as in other major cities in the region.

  10. Performance of commercial non-methane hydrocarbon analyzers in monitoring polar volatile organic compounds

    Science.gov (United States)

    Quantifying non-methane hydrocarbons (NMHC) from animal feeding operations (AFOs) is challenging due to the broad spectrum of compounds and the polar nature of the most abundant compounds. The purpose of this study was to determine the performance of commercial NMHC analyzers for measuring volatile ...

  11. PTR-MS measurements of non-methane volatile organic compounds during an intensive field campaign at the summit of Mount Tai, China, in June 2006

    Science.gov (United States)

    Inomata, S.; Tanimoto, H.; Kato, S.; Suthawaree, J.; Kanaya, Y.; Pochanart, P.; Liu, Y.; Wang, Z.

    2010-08-01

    Owing to recent industrialization, Central East China has become a significant source of air pollutants. To examine the processes controlling the chemistry and transport of tropospheric ozone, we performed on-line measurements of non-methane volatile organic compounds (NMVOCs) as part of an intensive field campaign at Mount Tai, China, in June 2006 (MTX2006), using proton transfer reaction mass spectrometry (PTR-MS). Temporal variations of NMVOCs were recorded in mass-scan mode from m/z17 to m/z 300 during 12-30 June 2006. More than thirty kinds of NMVOCs were detected up to m/z 160, including alkenes, aromatics, alcohols, aldehydes, and ketones. In combination with non-methane hydrocarbon data obtained by a gas chromatography with flame ionization detection, it was found that oxygenated VOCs were the predominant NMVOCs. Diurnal variations depending mainly on local photochemistry were observed during 24-28 June. During the night of 12 June, we observed an episode of high NMVOCs concentrations attributed to the burning of agricultural biomass. The ΔNMVOCs/ΔCO ratios derived by PTR-MS measurements for this episode (with biomass burning (BB) plume) and during 16-23 June (without BB plume) are compared to emission ratios from various types of biomass burning as reviewed by Andreae and Merlet (2001) and to ratios recently measured by PTR-MS in tropical forests (Karl et al., 2007) and at urban sites (Warneke et al., 2007).

  12. Influence of oil and gas emissions on ambient atmospheric non-methane hydrocarbons in residential areas of Northeastern Colorado

    Directory of Open Access Journals (Sweden)

    Chelsea R. Thompson

    2014-11-01

    Full Text Available Abstract The Northern Front Range (NFR region of Colorado has experienced rapid expansion of oil and gas extraction from shale and tight sands reservoirs in recent years due to advances in hydraulic fracturing technology, with over 25,000 wells currently in operation. This region has also been designated as a federal ozone non-attainment area by the U.S. EPA. High ozone levels are a significant health concern, as are potential health impacts from chronic exposure to primary emissions of non-methane hydrocarbons (NMHC for residents living near wells. From measurements of ambient atmospheric NMHC present in residential areas located in close proximity to wells in Erie, Colorado, we find that mean mole fractions of the C2–C5 alkanes are enhanced by a factor of 18–77 relative to the regional background, and present at higher levels than typically found in large urban centers. When combined with NMHC observations from downtown Denver and Platteville, it is apparent that these compounds are elevated across the NFR, with highest levels within the Greater Wattenberg Gas Field. This represents a large area source for ozone precursors in the NFR. The BTEX aromatic compounds in Erie were comparable to (e.g., benzene or lower than (e.g., toluene, ethylbenzene, xylene in large urban centers, however, benzene was significantly higher in Platteville, and within the range of chronic health-based exposure levels. An initial look at comparisons with data sets from previous years reveal that ambient levels for oil and gas-related NMHC in Erie, as well as further downwind in Boulder, have not decreased, but appear to have been increasing, despite tightening of emissions standards for the oil and gas industries in 2008.

  13. Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation

    Science.gov (United States)

    Rumsey, Ian Cooper

    Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were made from both an anaerobic lagoon and barn at a swine CAFO in North Carolina. Emission measurements were made over all four seasonal periods. In each seasonal period, measurements were made from both the anaerobic lagoon and barn for ˜1 week. RSC and NMVOCs samples were collected using passivated canisters. Nine to eleven canister samples were taken from both the lagoon and barn over each sampling period. The canisters were analyzed ex-situ using gas chromatography flame ionization detection (GC-FID). Hydrogen sulfide (H2S) measurements were made in-situ using a pulsed fluorescence H2S/SO2 analyzer. During sampling, measurements of meteorological and physiochemical parameters were made. H2S had the largest RSC flux, with an overall average lagoon flux of 1.33 mug m-2 min-1. The two main RSCs identified by the GC-FID, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), had overall average lagoon fluxes an order of magnitude lower, 0.12 and 0.09 mug m-2 min-1, respectively. Twelve significant NMVOCs were identified in lagoon samples (ethanol, 2-ethyl-1-hexanol, methanol, acetaldehyde, decanal, heptanal, hexanal, nonanal, octanal, acetone, methyl ethyl ketone, and 4-methylphenol). The overall average fluxes for these NMVOCs, ranged from 0.08 mug m-2 min-1 (4-methylphenol) to 2.11 mug m-2 min-1 (acetone). Seasonal H2S barn concentrations ranged from 72-631 ppb. DMS and DMDS seasonal concentrations were 2-3 orders of magnitude lower. There were six significant NMVOCs identified in barn samples (methanol, ethanol, acetone 2-3 butanedione, acetaldehyde

  14. Speciation of anthropogenic emissions of non-methane volatile organic compounds: a global gridded data set for 1970–2012

    Directory of Open Access Journals (Sweden)

    G. Huang

    2017-06-01

    Full Text Available Non-methane volatile organic compounds (NMVOCs include a large number of chemical species which differ significantly in their chemical characteristics and thus in their impacts on ozone and secondary organic aerosol formation. It is important that chemical transport models (CTMs simulate the chemical transformation of the different NMVOC species in the troposphere consistently. In most emission inventories, however, only total NMVOC emissions are reported, which need to be decomposed into classes to fit the requirements of CTMs. For instance, the Emissions Database for Global Atmospheric Research (EDGAR provides spatially resolved global anthropogenic emissions of total NMVOCs. In this study the EDGAR NMVOC inventory was revised and extended in time and in sectors. Moreover the new version of NMVOC emission data in the EDGAR database were disaggregated on a detailed sector resolution to individual species or species groups, thus enhancing the usability of the NMVOC emission data by the modelling community. Region- and source-specific speciation profiles of NMVOC species or species groups are compiled and mapped to EDGAR processes (detailed resolution of sectors, with corresponding quality codes specifying the quality of the mapping. Individual NMVOC species in different profiles are aggregated to 25 species groups, in line with the common classification of the Global Emissions Initiative (GEIA. Global annual grid maps with a resolution of 0.1°  ×  0.1° for the period 1970–2012 are produced by sector and species. Furthermore, trends in NMVOC composition are analysed, taking road transport and residential sources in Germany and the United Kingdom (UK as examples.

  15. Simultaneous monitoring of atmospheric methane and speciated non-methane hydrocarbon concentrations using Peltier effect sub-ambient pre-concentration and gas chromatography.

    Science.gov (United States)

    Harrison, D; Seakins, P W; Lewis, A C

    2000-02-01

    Sub-ambient trapping, used to pre-concentrate atmospheric samples for non-methane hydrocarbon (NMHC) analysis by gas chromatography, can also be used to measure ambient methane concentrations. Above a sample volume of 40 ml, a dynamic equilibrium is established between ambient and trapped methane allowing for simultaneous quantitative determinations of methane and NMHC. The temperature stability of the trap is critical for quantitative methane analysis and this can be achieved by Peltier effect cooling. Simultaneous measurements of methane and NMHC reduce the equipment required for field trips and can ease the interpretation and modelling of atmospheric data. The feasibility for deployment of the system in remote locations was demonstrated by running the apparatus virtually unattended for a 5-day period. The correlations between the concentrations of methane, ethane and ethene measured during this period are discussed.

  16. Influence of oil and gas field operations on spatial and temporal distributions of atmospheric non-methane hydrocarbons and their effect on ozone formation in winter

    Directory of Open Access Journals (Sweden)

    R. A. Field

    2014-09-01

    Full Text Available Emissions from oil and natural gas development during winter in the Upper Green River Basin of Wyoming are known to drive episodic ozone (O3 production. Contrasting O3 distributions were observed in the winters of 2011 and 2012, with numerous episodes in 2011 compared to none in 2012. During 2011 wintertime O3 episodes at two sites near Boulder Wyoming, situated ∼5 km apart, were observed to sometimes differ. In 2012 the lack of O3 episodes coincided with a reduction in ambient levels of total non-methane hydrocarbons (NMHC. Measurements of speciated NMHC, and other air quality parameters, were performed to better understand emission sources and to determine which compounds are most active in promoting O3 formation. Positive Matrix Factorization (PMF analyses of the data were carried out to help achieve these goals. PMF analyses revealed three contributing factors that were identified with different emission source types: factor 1, combustion/traffic; factor 2, fugitive natural gas; and factor 3, fugitive condensate. Compositional signatures of three contributing factors were identified through comparison with independently derived emission source profiles. Fugitive emissions of natural gas and of condensate were the two principal emission source types for NMHC. A water treatment and recycling facility was found to be a significant source of condensate range NMHC, in particular toluene and m+p-xylene. Emissions from water treatment have an influence upon peak O3 mixing ratios at downwind measurement sites.

  17. Improved provincial emission inventory and speciation profiles of anthropogenic non-methane volatile organic compounds: a case study for Jiangsu, China

    Directory of Open Access Journals (Sweden)

    Y. Zhao

    2017-06-01

    Full Text Available Non-methane volatile organic compounds (NMVOCs are the key precursors of ozone (O3 and secondary organic aerosol (SOA formation. Accurate estimation of their emissions plays a crucial role in air quality simulation and policy making. We developed a high-resolution anthropogenic NMVOC emission inventory for Jiangsu in eastern China from 2005 to 2014, based on detailed information of individual local sources and field measurements of source profiles of the chemical industry. A total of 56 NMVOCs samples were collected in nine chemical plants and were then analyzed with a gas chromatography – mass spectrometry system (GC-MS. Source profiles of stack emissions from synthetic rubber, acetate fiber, polyether, vinyl acetate and ethylene production, and those of fugitive emissions from ethylene, butanol and octanol, propylene epoxide, polyethylene and glycol production were obtained. Various manufacturing technologies and raw materials led to discrepancies in source profiles between our domestic field tests and foreign results for synthetic rubber and ethylene production. The provincial NMVOC emissions were calculated to increase from 1774 Gg in 2005 to 2507 Gg in 2014, and relatively large emission densities were found in cities along the Yangtze River with developed economies and industries. The estimates were larger than those from most other available inventories, due mainly to the complete inclusion of emission sources and to the elevated activity levels from plant-by-plant investigation in this work. Industrial processes and solvent use were the largest contributing sectors, and their emissions were estimated to increase, respectively, from 461 to 958 and from 38 to 966 Gg. Alkanes, aromatics and oxygenated VOCs (OVOCs were the most important species, accounting for 25.9–29.9, 20.8–23.2 and 18.2–21.0 % to annual total emissions, respectively. Quantified with a Monte Carlo simulation, the uncertainties of annual NMVOC emissions

  18. Improved provincial emission inventory and speciation profiles of anthropogenic non-methane volatile organic compounds: a case study for Jiangsu, China

    Science.gov (United States)

    Zhao, Yu; Mao, Pan; Zhou, Yaduan; Yang, Yang; Zhang, Jie; Wang, Shekou; Dong, Yanping; Xie, Fangjian; Yu, Yiyong; Li, Wenqing

    2017-06-01

    Non-methane volatile organic compounds (NMVOCs) are the key precursors of ozone (O3) and secondary organic aerosol (SOA) formation. Accurate estimation of their emissions plays a crucial role in air quality simulation and policy making. We developed a high-resolution anthropogenic NMVOC emission inventory for Jiangsu in eastern China from 2005 to 2014, based on detailed information of individual local sources and field measurements of source profiles of the chemical industry. A total of 56 NMVOCs samples were collected in nine chemical plants and were then analyzed with a gas chromatography - mass spectrometry system (GC-MS). Source profiles of stack emissions from synthetic rubber, acetate fiber, polyether, vinyl acetate and ethylene production, and those of fugitive emissions from ethylene, butanol and octanol, propylene epoxide, polyethylene and glycol production were obtained. Various manufacturing technologies and raw materials led to discrepancies in source profiles between our domestic field tests and foreign results for synthetic rubber and ethylene production. The provincial NMVOC emissions were calculated to increase from 1774 Gg in 2005 to 2507 Gg in 2014, and relatively large emission densities were found in cities along the Yangtze River with developed economies and industries. The estimates were larger than those from most other available inventories, due mainly to the complete inclusion of emission sources and to the elevated activity levels from plant-by-plant investigation in this work. Industrial processes and solvent use were the largest contributing sectors, and their emissions were estimated to increase, respectively, from 461 to 958 and from 38 to 966 Gg. Alkanes, aromatics and oxygenated VOCs (OVOCs) were the most important species, accounting for 25.9-29.9, 20.8-23.2 and 18.2-21.0 % to annual total emissions, respectively. Quantified with a Monte Carlo simulation, the uncertainties of annual NMVOC emissions vary slightly through the years

  19. Emission, speciation, and evaluation of impacts of non-methane volatile organic compounds from open dump site.

    Science.gov (United States)

    Majumdar, Dipanjali; Ray, Sandipan; Chakraborty, Sucharita; Rao, Padma S; Akolkar, A B; Chowdhury, M; Srivastava, Anjali

    2014-07-01

    Surface emission from Dhapa, the only garbage disposal ground in Kolkata, is a matter of concern to the local environment and also fuels the issues of occupational and environmental health. Surface emission of the Dhapa landfill site was studied using a flux chamber measurement for nonmethane volatile organic compounds (NMVOCs). Eighteen noncarbonyl volatile organic compounds (VOCs) and 14 carbonyl VOCs, including suspected and known carcinogens, were found in appreciable concentrations. The concentrations of the target species in the flux chamber were found to be significantly higher for most of the species in summer than winter. Surface emission rate of landfill gas was estimated by using two different approaches to assess the applicability for an open landfill site. It was found that the emissions predicted using the model Land GEM version 3.02 is one to two orders less than the emission rate calculated from flux chamber measurement for the target species. Tropospheric ozone formation has a serious impact for NMVOC emission. The total ozone-forming potential (OFP) of the Dhapa dumping ground considering all target NMVOCs was estimated to be 4.9E+04 and 1.2E+05 g/day in winter and summer, respectively. Also, it was found that carbonyl VOCs play a more important role than noncarbonyl VOCs for tropospheric ozone formation. Cumulative cancer risk estimated for all the carcinogenic species was found to be 2792 for 1 million population, while the total noncancer hazard index (HI) was estimated to be 246 for the occupational exposure to different compounds from surface emission to the dump-site workers at Dhapa. Implications: This paper describes the real-time surface emission of NMVOCs from an open municipal solid waste (MSW) dump site studied using a flux chamber. Our study findings indicate that while planning for new landfill site in tropical meteorology, real-time emission data must be considered, rather than relying on modeled data. The formation of tropospheric

  20. Analysis of non-methane hydrocarbon data from a monitoring station affected by oil and gas development in the Eagle Ford shale, Texas

    Directory of Open Access Journals (Sweden)

    Gunnar W. Schade

    2016-03-01

    Full Text Available Abstract Within the last decade, unconventional oil and gas exploration in the US has become a new source of atmospheric hydrocarbons. Although a geographically dispersed source, field measurements in and downwind of a number of shale basins demonstrate the impact exploration activities have on ambient levels of hydrocarbons. Due to concerns related to ozone production, regulatory agencies are adding monitoring stations to better understand the potential influence of emissions from areas with increased oil and gas related activities. The Eagle Ford shale in south Texas is a rapidly developing shale play producing both oil and natural gas, providing 10% and 5% of US domestic oil and gas production, respectively, in 2013. We analyzed the first year of measurements from a newly established monitoring site at its central north edge. The data reveal median ethane mixing ratios—used as a marker for oil and gas exploration related emissions—at five times its typical clean air background. Ethane mixing ratios above ten times the background occurred regularly. Saturated hydrocarbons with likely origin in oil and gas exploration explain half of the data set’s variability. They dominate OH radical reactivity at levels both similar to other shale areas and similar to Houston’s ship channel area a decade ago. Air advecting slowly across the shale area from east-southeast and southwest directions shows the most elevated hydrocarbon concentrations, and evidence is presented linking elevated alkene abundances to flaring in the shale area. A case study is presented linking high emissions from an upwind facility to hydrocarbon plumes observed at the monitor.

  1. Emission inventory of NMVOC (Non Methane Volatile Organic Compounds) and simulations of ozone formation due to emissions of NO{sub x} and NMVOC in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Janhaell, S.; Andersson-Skoeld, Y.

    1997-01-01

    An emission inventory, covering the different source categories of ozone precursors in Sweden, has been performed. The emissions from each category, road traffic, working machinery, other mobile sources, wood combustion, energy production, industry, domestic use and pesticides, have been separated into 81 organic compounds and NO{sub x}. The emission data have been used in model simulations to predict the ozone formation due to the emission from different source categories. Four different ambient conditions have been treated. The results from this study indicate, as expected, that the road traffic is the single most important emitter of precursors significant in regional ozone production. POCP, or Photochemical Ozone Creation Potential, defined as the change in photochemical ozone production due to a change in the emission of that particular VOC, is used to compare different VOC in connection with ozone production. In this study the POCP was calculated for the whole group of compounds emitted from a specific source category. The results indicate that there is a big variety of ozone formation ability among source categories due to differences in composition, which clearly demonstrate the importance of a detailed description of the emissions. 48 refs, 5 figs, 6 tabs

  2. Use of chloroflurocarbons as internal standards for the measurement of atmospheric non-methane volatile organic compounds sampled onto solid adsorbent cartridges.

    Science.gov (United States)

    Karbiwnyk, Christine M; Mills, Craig S; Helmig, Detlev; Birks, John W

    2003-03-01

    Solid adsorbents have proven useful for determining the vertical profiles of volatile organic compounds (VOCs) using sampling platforms such as balloons, kites, and light aircraft, and those profiles provide valuable information about the sources, sinks, transformations, and transport of atmospheric VOCs. One of the largest contributions to error in VOC concentrations is the estimation of the volume of air sampled on the adsorbent cartridge. These errors arise from different sources, such as variations in pumping flow rates from changes in ambient temperature and pressure with altitude, and decrease in the sampling pump battery power. Another significant source for sampling rate variations are differences in the flow resistance of individual sampling cartridges. To improve the accuracy and precision of VOC measurements, the use of ambient chlorofluorocarbons (CFCs) as internal standards was investigated. A multibed solid adsorbent, AirToxic (Supelco), was chosen for its wide sampling range (C3-C12). Analysis was accomplished by thermal desorption and dual detection GC/FID/ECD, resulting in sensitive and selective detection of both VOCs and CFCs in the same sample. Long-lived chlorinated compounds (CFC-11, CFC-12, CFC-113, CCl4 and CH3CCl3) banned by the Montreal Protocol and subsequent amendments were studied for their ability to predict sample volumes using both ground-based and vertical profiling platforms through the boundary layer and free troposphere. Of these compounds, CFC-113 and CCl4 were found to yield the greatest accuracy and precision for sampling volume determination. Use of ambient CFC-113 and CCl4 as internal standards resulted in accuracy and precision of generally better than 10% for the prediction of sample volumes in ground-, balloon-, and aircraft-based measurements. Consequently, use of CFCs as reference compounds can yield a significant improvement of accuracy and precision for ambient VOC measurements in situations where accurate flow

  3. A refined method for the calculation of the Non-Methane Volatile Organic Compound emission estimate from Domestic Solvent Usage in Ireland from 1992 to 2014 - A case study for Ireland

    Science.gov (United States)

    Barry, Stephen; O'Regan, Bernadette

    2016-08-01

    This study describes a new methodology to calculate Non-Methane Volatile Organic Compounds from Domestic Solvent Use including Fungicides over the period 1992-2014. Improved emissions data compiled at a much more refined level can help policy-makers develop more effective policy's to address environmental issues. However, a number of problems were found when member states attempt to use national statistics for Domestic Solvent Use including Fungicides. For instance, EMEP/EEA (2013) provides no guidance regarding which activity data should be used, resulting in emission estimates being potentially inconsistent and un-comparable. Also, previous methods and emission factors described in the EMEP/EEA (2013) guidebook do not exactly match data collected by state agencies. This makes using national statistics difficult. In addition, EMEP/EEA (2013) use broader categories than necessary (e.g. Cosmetics Aerosol/Non Aerosol) to estimate emissions while activity data is available at a more refined level scale (e.g. Personal Cleaning Products, Hair Products, Cosmetics, Deodorants and Perfumes). This can make identifying the drivers of emissions unclear. This study builds upon Tzanidakis et al. (2012) whereby it provides a method for collecting activity data from state statistics, developed country specific emission factors based on a survey of 177 Irish products and importantly, used a new method to account for the volatility of organic compounds found in commonly available domestic solvent containing products. This is the first study to account for volatility based on the characteristics of organic compounds and therefore is considered a more accurate method of accounting for emissions from this emission source. The results of this study can also be used to provide a simple method for other member parties to account for the volatility of organic compounds using sectorial adjustment factors described here. For comparison purposes, emission estimates were calculated using the

  4. Measurement of stable carbon isotope ratios of non-methane hydrocarbons and halocarbons

    NARCIS (Netherlands)

    Zuiderweg, A.T.

    2012-01-01

    Within the realm of volatile organic compounds, hydrocarbons and halocarbons form a sizable proportion of carbon input to the atmosphere. Within these compound categories, the light non-methane hydrocarbons (NMHC, two to seven carbon atoms) and monocarbon halocarbons have a special place as these

  5. Observations of the release of non-methane hydrocarbons from fractured shale.

    Science.gov (United States)

    Sommariva, Roberto; Blake, Robert S; Cuss, Robert J; Cordell, Rebecca L; Harrington, Jon F; White, Iain R; Monks, Paul S

    2014-01-01

    The organic content of shale has become of commercial interest as a source of hydrocarbons, owing to the development of hydraulic fracturing ("fracking"). While the main focus is on the extraction of methane, shale also contains significant amounts of non-methane hydrocarbons (NMHCs). We describe the first real-time observations of the release of NMHCs from a fractured shale. Samples from the Bowland-Hodder formation (England) were analyzed under different conditions using mass spectrometry, with the objective of understanding the dynamic process of gas release upon fracturing of the shale. A wide range of NMHCs (alkanes, cycloalkanes, aromatics, and bicyclic hydrocarbons) are released at parts per million or parts per billion level with temperature- and humidity-dependent release rates, which can be rationalized in terms of the physicochemical characteristics of different hydrocarbon classes. Our results indicate that higher energy inputs (i.e., temperatures) significantly increase the amount of NMHCs released from shale, while humidity tends to suppress it; additionally, a large fraction of the gas is released within the first hour after the shale has been fractured. These findings suggest that other hydrocarbons of commercial interest may be extracted from shale and open the possibility to optimize the "fracking" process, improving gas yields and reducing environmental impacts.

  6. Assessing Emissions of Volatile Organic Componds from Landfills Gas

    Directory of Open Access Journals (Sweden)

    Fahime Khademi

    2016-01-01

    Full Text Available Background: Biogas is obtained by anaerobic decomposition of organic wastes buried materials used to produce electricity, heat and biofuels. Biogas is at the second place for power generation after hydropower and in 2000 about 6% of the world power generation was allocated to biogas. Biogas is composed of 40–45 vol% CO2, 55–65 vol% CH4, and about 1% non-methaneVOCs, and non-methane volatile organic compounds. Emission rates are used to evaluate the compliance with landfill gas emission regulations by the United States Environmental Protection Agency (USEPA. BTEX comounds affect the air quality and may be harmful to human health. Benzene, toluene, ethylbenzene and xylene isomers that are generally called BTEX compounds are the most abundant VOCs in biogas. Methods: Sampling of VOCs in biogas vents was operated passively or with Tedlar bags. 20 samples were collected from 40 wells of old and new biogas sites of Shiraz’ landfill. Immediately after sampling, the samples were transferred to the laboratory. Analysis of the samples was performed with GC-MS. Results: The results showed that in the collection of the old and new biogas sites, the highest concentration of VOCs was observed in toluene (0.85ppm followed by benzene (0.81ppm, ethylbenzene (0.13ppm and xylene (0.08ppm. Conclusion: The results of the study showed that in all samples, most available compounds in biogas vents were aromatic hydrocarbon compounds.These compounds’ constituents originate from household hazardous waste materials deposited in the landfill or from biological/chemical decomposition processes within the landfill.

  7. New off-line aircraft instrumentation for non-methane hydrocarbon measurements.

    Science.gov (United States)

    Bechara, Joelle; Borbon, Agnès; Jambert, Corinne; Perros, Pascal E

    2008-11-01

    New off-line instrumentation was developed to implement measurements of non-methane hydrocarbons (NMHC) on (French) research aircraft. NMHC are collected on multisorbent tubes by AMOVOC (Airborne Measurements Of Volatile Organic Compounds), a new automatic sampler. AMOVOC is a versatile and portable sampler targeting a wide range of NMHC at high frequency (sampling time of 10 min). Multisorbent tubes are analyzed on the ground by short-path thermal desorption coupled with gas chromatography and mass spectrometry. The development and optimization of both NMHC sampling and analysis are reported here. On the one hand, the paper points out technical choices that were made according to aircraft constraints and avoiding sample loss or contamination. On the other hand, it describes analytical optimization, tube storage stability, and moisture removal. The method shows high selectivity, sensitivity (limit of detection less than 10 ppt) and precision (less than 24%). Finally, NMHC data collected on French aircraft during the African Monsoon Multidisciplinary Analysis campaign are reported for the first time. The results highlight instrumentation validity and protocol efficiency for NMHC measurements in the lower and upper troposphere.

  8. Emissions of non-methane hydrocarbons from cars in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This study investigated the exhaust emission of non-methane hydrocarbons(NMHCs) from cars in China at the Beijing driving cycle on the chassis dynamometer.The emission factor average of NMHCs was 0.9 g/km,which was over twice that from the Australian car fleet and 2-4 times that of the American car emission in the 1990s-2000s.The emission profile of Beijing cars showed higher fractions of aromatics and C4?C7 HCs,and lower percentages of C2?C3 HCs,compared with those of the US car fleet.The average ratio of benzene/toluene for cars tested was 0.5,the average benzene/toluene/ethyl benzene/xylenes(BTEX) ratios were 1/2.2/0.1/1.8,which were consistent with those of the Tanyugou tunnel located in the suburb of Beijing.α-pinene and β-pinene were detected from the exhaust gas on dynamometer for the first time,and had likely similar exhaust emission characteristics with C2?C3 HCs and styrene,giving an evidence that air pinenes may be related to human activities.Isoprene was also detected directly.These observations suggest that the procedure regarding pinenes and isoprene as coming from biologic sources of VOCs in the atmosphere should be applied with great care,especially in the core of the big city like Beijing.The specific reactivity of NMHCs was higher than that of cars of US,and the specific reactivity of volatile aromatic compounds was higher than that of the US SPECIATE database.

  9. Characterization of non-methane hydrocarbons in Asian summer monsoon outflow observed by the CARIBIC aircraft

    Directory of Open Access Journals (Sweden)

    A. K. Baker

    2010-07-01

    Full Text Available Between April and December 2008 the CARIBIC commercial aircraft conducted monthly measurement flights between Frankfurt, Germany and Chennai, India. These flights covered the period of the Asian summer monsoon (June–September, during which enhancements in a number of atmospheric species were observed in monsoon outflow. In addition to in situ measurements of trace gases and aerosols, whole air samples were collected during the flights, and these were subsequently analyzed for a suite of trace gases that included the non-methane hydrocarbons. Non-methane hydrocarbons are relatively short-lived compounds and the large enhancements in their mixing ratios in the upper troposphere over Southwest Asia between June and September, sometimes more than double their spring and fall means, provides qualitative evidence for the influence of convectively uplifted boundary layer air. The particularly large enhancements of the combustion tracers benzene and ethyne, along with the similarity of their ratios to carbon monoxide and emission ratios from the burning of household biofuels, indicate a strong influence of biofuel burning to NMHC emissions in this region. Conversely, the ratios of ethane and propane to carbon monoxide, along with the ratio between i-butane and n-butane, indicate a significant source of these compounds from the use of LPG and natural gas, and comparison to previous campaigns suggests that this source could be increasing. Photochemical aging patterns of NMHCs showed that the CARIBIC samples were collected in two distinctly different regions of the monsoon circulation: a southern region where air masses had been recently influenced by low level contact and a northern region, where air parcels had spent substantial time in transit in the upper troposphere before being probed. Estimates of age using ratios of individual NMHCs have ranges of 3–6 d in the south and 9–12 d in the north.

  10. The carbon isotopic compositions of Non-methane Hydrocarbons in atmosphere

    Institute of Scientific and Technical Information of China (English)

    PENG Lin; ZHANG HuiMin; REN ZhaoFang; MU Ling; SHI RuiLiang; CHANG LiPing; LI Fan

    2009-01-01

    Carbon isotopic compositions of atmospheric Non-methane Hydrocarbons (NMHCs) in the urban areas of Taiyuan and Lanzhou in summer were reported and the sources of NMHCs are discussed.Carbon isotopic ratios (δ13C) of vehicle exhaust,coal-combustion exhaust,fuel volatiles and cooking exhaust were also measured with thermal desorption-gas chromatography-isotope ratio-mass spectrometry (TD-GC-IR-MS).δ13C values of NMHCs in the urban areas of Lanzhou and Taiyuan range from -32.3‰ to -22.3‰ and from -32.8‰ to -18.1‰.δ13C values of vehicle exhaust,coal-combustion exhaust,fuel volatiles and cooking exhaust are -32.5‰--21.7‰,-24.5‰--22.3‰,-32.5%--27.4‰ and -31.6‰--24.5‰,respectively.The data indicate that vehicle exhaust and cooking exhaust make a significant contribution to the atmospheric NMHCs.Therefore,to reduce emissions of vehicle exhaust and cook-ing exhaust is critical for controlling atmospheric NMHCs pollution in summer.

  11. Solid Organic Deposition During Gas Injection Studies

    DEFF Research Database (Denmark)

    Dandekar, Abhijit Y.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    2000-01-01

    Recently a series of first contact miscibility (swelling) experiments have been performed on undersaturated light and heavy oils using LPG rich and methane rich injection gases, in which solid organic deposition was observed. A compositional gradient in the oils during the gas injection process w...

  12. Reconstruction of Northern Hemisphere 1950-2010 atmospheric non-methane hydrocarbons

    NARCIS (Netherlands)

    Helmig, D.; Petrenko, V.; Martinerie, P.; Witrant, E.; Rockmann, T.; Zuiderweg, A.; Holzinger, R.; Hueber, J.; Thompson, C.; White, J. W. C.; Sturges, W.; Baker, A.; Blunier, T.; Etheridge, D.; Rubino, M.; Tans, P.

    2014-01-01

    The short-chain non-methane hydrocarbons (NMHC) are mostly emitted into the atmosphere by anthropogenic processes. Recent studies have pointed out a tight linkage between the atmospheric mole fractions of the NMHC ethane and the atmospheric growth rate of methane. Consequently, atmospheric NMHC are

  13. Reconstruction of Northern Hemisphere 1950-2010 atmospheric non-methane hydrocarbons

    NARCIS (Netherlands)

    Helmig, D.; Petrenko, V.; Martinerie, P.; Witrant, E.; Rockmann, T.; Zuiderweg, A.; Holzinger, R.; Hueber, J.; Thompson, C.; White, J. W. C.; Sturges, W.; Baker, A.; Blunier, T.; Etheridge, D.; Rubino, M.; Tans, P.

    2014-01-01

    The short-chain non-methane hydrocarbons (NMHC) are mostly emitted into the atmosphere by anthropogenic processes. Recent studies have pointed out a tight linkage between the atmospheric mole fractions of the NMHC ethane and the atmospheric growth rate of methane. Consequently, atmospheric NMHC are

  14. Non-methane hydrocarbons over the Eastern Mediterranean during summer, measured from northwest Cyprus

    Science.gov (United States)

    Sauvage, Carina; Derstroff, Bettina; Bourtsoukidis, Efstratios; Keßel, Stephan; Thorenz, Ute; Baker, Angela; Williams, Jonathan; Lelieveld, Jos

    2015-04-01

    In summer 2014 the CYprus Photochemistry EXperiment (CYPHEX) field campaign took place at an elevated (600m) measurement site in the north western part of Cyprus close (10 km) to the coast (35,96N, 32,4E) in order to investigate the photochemistry and air mass transport of the eastern Mediterranean. Non-methane hydrocarbons were measured with a commercial GC-FID (AMA instruments GmbH, Ulm, Germany) with a final dataset consisting of two weeks of continuous, hourly measurements for 10 NMHC. NMHCs are a class of volatile organic compounds (VOC) which are emitted by both anthropogenic and natural sources. Their predominant sink in the atmosphere is photochemically driven oxidation by OH radicals. Their atmospheric lifetimes, which range from a few days for more reactive compounds such as pentanes and butanes and up to a month for less reactive ones like ethane, make it possible to deduce photochemical histories and transport regimes from NMHC observations. Furthermore, in the presence of NOx they are important precursors for tropospheric ozone. Backward trajectories show that the airmasses reaching the measurement site had been influenced periodically by emissions from western continental Europe (France, Spain) that crossed the Mediterranean Sea and from eastern continental Europe (Greece and Turkey) more recently influenced by industrial emissions. Varying patterns in NMHC data delineates these two regimes very well, with aged western European air masses being characterized by low level ethane and with toluene and benzene being higher and more variable in plumes from eastern Europe. Additionally, atypical n-butane and i-butane ratios suggest a deviation from the expected predominant oxidation by OH, possibly indicating reaction with chlorine radicals (Cl). The dataset has been evaluated with respect to NMHC sources and oxidative history using different methods of approach.

  15. Variation of ambient non-methane hydrocarbons in Beijing city in summer 2008

    Directory of Open Access Journals (Sweden)

    B. Wang

    2010-02-01

    Full Text Available In conjunction with hosting the 2008 Beijing Olympics, the municipal government implemented a series of stringent air quality control measures. To assess the impacts on variation of ambient non-methane hydrocarbons (NMHCs, the whole air was sampled by canisters at one urban site and two suburban sites in Beijing, and 55 NMHC species were quantified by gas chromatography equipped with a quadrupole mass spectrometer and a flame ionization detector (GC/MSD/FID as parts of the field Campaign for the Beijing Olympic Games Air Quality program (CareBeijing. According to the control measures, the data were presented according to four periods: 18–30 June, 8–19 July, 15–24 August (during the Olympic Games, and 6–15 September (during the Paralympic Games. Compared with the levels in June, the mixing ratios of NMHCs obtained in the Olympic and Paralympic Games periods were reduced by 35% and 25%, respectively. Source contributions were calculated using a chemical mass balance model (CMB 8.2. After implementing the control measures, emissions from target sources were obviously reduced, and reductions in vehicle exhaust could explain 48–82% of the reductions of ambient NMHCs. Reductions in emissions from gasoline evaporation, paint and solvent use, and the chemical industry contributed 9–40%, 3–24%, and 1–5%, respectively, to reductions of ambient NMHCs. Sources of liquefied petroleum gas (LPG and biogenic emissions were not controlled, and contributions from these sources from July to September were stable or even higher than in June. Ozone formation potentials (OFPs were calculated for the measured NMHCs. The total OFPs during the Olympic and Paralympic Games were reduced by 48% and 32%, respectively, compared with values in June. Reductions in the OFPs of alkenes and aromatics explained 77–92% of total OFP reductions. The alkenes and aromatics were mainly from vehicle exhausts, and reductions of vehicle exhaust gases explained 67–87% of

  16. Network monitoring of speciated vs. total non-methane hydrocarbon measurements

    Science.gov (United States)

    Chen, Sheng-Po; Liao, Wei-Cheng; Chang, Chih-Chung; Su, Yuan-Chang; Tong, Yu-Huei; Chang, Julius S.; Wang, Jia-Lin

    2014-06-01

    The total non-methane hydrocarbon (TNMHC) level in the atmosphere is defined as the level of total hydrocarbons minus the level of methane. TNMHC observations are made in selected air quality stations (AQS) of Environmental Protection Agency (EPA) across Taiwan. The AQS network is also complemented by a network of photochemical assessment monitoring stations (PAMS) to provide hourly observations of 56 speciated non-methane hydrocarbons (NMHCs). In this study, the relationship between the AQS and PAMS TNMHC values was cross-examined for the period of 2007-2011 at four sites that conducted both types of measurements. Although the two observations differ in their methods of collection, the variations in the two datasets showed high synchronicity. However, because some of the NMHCs were missed in the summation of 56 species, the PAMS TNMHC values were consistently lower than those of the AQS TNMHC by an average of 30%.

  17. Primary emissions and secondary formation of volatile organic compounds from natural gas production in five major U.S. shale plays

    Science.gov (United States)

    Gilman, J.; Lerner, B. M.; Warneke, C.; Graus, M.; Lui, R.; Koss, A.; Yuan, B.; Murphy, S. M.; Alvarez, S. L.; Lefer, B. L.; Min, K. E.; Brown, S. S.; Roberts, J. M.; Osthoff, H. D.; Hatch, C. D.; Peischl, J.; Ryerson, T. B.; De Gouw, J. A.

    2014-12-01

    According to the U.S. Energy and Information Administration (EIA), domestic production of natural gas from shale formations is currently at the highest levels in U.S. history. Shale gas production may also result in the production of natural gas plant liquids (NGPLs) such as ethane and propane as well as natural gas condensate composed of a complex mixture of non-methane hydrocarbons containing more than ~5 carbon atoms (e.g., hexane, cyclohexane, and benzene). The amounts of natural gas liquids and condensate produced depends on the particular reservoir. The source signature of primary emissions of hydrocarbons to the atmosphere within each shale play will therefore depend on the composition of the raw natural gas as well as the industrial processes and equipment used to extract, separate, store, and transport the raw materials. Characterizing the primary emissions of VOCs from natural gas production is critical to assessing the local and regional atmospheric impacts such as the photochemical formation of ozone and secondary formation of organic aerosol. This study utilizes ground-based measurements of a full suite of volatile organic compounds (VOCs) in two western U.S. basins, the Uintah (2012-2014 winter measurements only) and Denver-Julesburg (winter 2011 and summer 2012), and airborne measurements over the Haynesville, Fayetteville, and Marcellus shale basins (summer 2013). By comparing the observed VOC to propane enhancement ratios, we show that each basin has a unique VOC source signature associated with oil and natural gas operations. Of the shale basins studied, the Uintah basin had the largest overall VOC to propane enhancement ratios while the Marcellus had the lowest. For the western basins, we will compare the composition of oxygenated VOCs produced from photochemical oxidation of VOC precursors and contrast the oxygenated VOC mixture to a "typical" summertime urban VOC mixture. The relative roles of alkanes, alkenes, aromatics, and cycloalkanes as

  18. Trends of non-methane hydrocarbons (NMHC emissions in Beijing during 2002–2013

    Directory of Open Access Journals (Sweden)

    M. Wang

    2014-07-01

    Full Text Available Non-methane hydrocarbons (NMHCs play a critical role in the photochemical production of ozone (O3 and organic aerosols. Obtaining an accurate understanding on NMHC emission trends is essential for predicting air quality changes and evaluating the effectiveness of current control measures. In this study, we evaluated temporal trends in NMHC emissions in Beijing based on ambient measurements during the summer at an urban site in Beijing from 2002 to 2013. In contrast to the results of the most recent inventory (Multi-resolution Emission Inventory for China, MEIC, which reported that total NMHC emissions increased at a rate of ~4% yr−1, mixing ratios of NMHCs measured at this urban site displayed an obvious decrease (~30% during the last decade. A Positive Matrix Factorization (PMF model was applied to the NMHC measurements for source apportionment, and the results showed a decrease in the concentrations contributed by transportation-related sources to total NMHC emissions by 66% during 2004–2012, which was comparable to the relative decline of 65% reported by the MEIC inventory. This finding indicates that the implementation of stricter emissions standards and control measures has been effective for reducing transportation-related NMHC emissions. In addition, the PMF results suggested that there were no significant temporal changes in NMHC concentrations from paint and solvent use during 2004–2012, in contrast with the rapid rate of increase (27.5% yr−1 reported by the MEIC inventory. To re-evaluate the NMHC emissions trends for paint and solvent use, annual variations in NMHC / NOx ratios were compared between ambient measurements and the MEIC inventory. In contrast to the significant rise in NMHC / NOx ratios from the inventory, the measured ratios declined by 14% during 2005–2012. However, the inferred NMHC / NOx ratios based on PMF results exhibited a comparable decline of 11% to measurements. These results indicate that the increase

  19. Non Methane Hydrocarbons (NMHCs) at the centre of Athens: variability and relative contribution of traffic and wood burning

    Science.gov (United States)

    Panopoulou, Anastasia; Liakakou, Eleni; Psiloglou, Basil; Gros, Valerie; Bonsang, Bernard; Sauvage, Stephane; Locoge, Nadine; Lianou, Maria; Gerasopoulos, Evangelos; Mihalopoulos, Nikolaos

    2016-04-01

    Non-methane hydrocarbons (NMHC) can be found in significant concentrations in urban areas. They are emitted by biogenic and anthropogenic sources like vehicle exhaust, gasoline evaporation and solvent use. Once emitted they mainly react with hydroxyl radicals (OH) and in the presence of nitrogen oxides (NOx) lead to the formation of secondary pollutants such as ozone (O3), peroxy acetyl nitrate (PAN) and secondary organic aerosols. In Great Athens Area (GAA) despite the numerous air quality issues especially with exceedances in ozone and particulate matter (PM), continuous monitoring of NMHCs is absent. This work presents the first results of a ChArMEX/TRANSEMED project dealing with VOC source apportionment and emission inventory evaluation in megacities around the Mediterranean basin. A representative site in the centre of Athens is progressively equipped with high performance instruments in order to measure continuously NMHCs (time resolution of 30 min) over a long period. The main objective of this presentation is the determination of the ambient level and temporal variability of C2-C6 NMHCs, as well as the impact of the sources controlling their variability. The importance of this work is attributed to the high time resolution measurements providing a detailed light hydrocarbons profile of the area for first time in the GAA. An automatic gas chromatograph (airmoVOC C2-C6 Chromatrap GC, Chromatotec, France) equipped with a flame ionization detector (FID) has been used for the in-situ measurements of NMHCS with two to six carbon atoms (C2-C6 NMHCs) during the period from the 16 of October to end of December 2015. In addition, meteorological and auxiliary data for major gases (CO, O3, NOx) and particulates (PM and Black Carbon (BC) are also available. Atmospheric concentrations of NMHCs range from below the detection limit to a few ppbs, for example almost 14 ppb, 20 ppb and 25 ppb for ethane, propane and acetylene respectively. Between the NMHCs being monitored

  20. Site characteristics in metal organic frameworks for gas adsorption

    Science.gov (United States)

    Uzun, Alper; Keskin, Seda

    2014-02-01

    Metal organic frameworks (MOFs) are a new class of nanoporous materials that have many potential advantages over traditional nanoporous materials for several chemical technologies including gas adsorption, catalysis, membrane-based gas separation, sensing, and biomedical devices. Knowledge on the interaction of guest molecules with the MOF surface is required to design and develop these MOF-based processes. In this review, we examine the importance of identification of gas adsorption sites in MOFs using the current state-of-the-art in experiments and computational modeling. This review provides guidelines to design new MOFs with useful surface properties that exhibit desired performances, such as high gas storage capacity, and high gas selectivity.

  1. Application of Organic Inclusions in Offshore Oil—Gas Exploration

    Institute of Scientific and Technical Information of China (English)

    周雯雯

    1999-01-01

    Studies of organic inclusions from the offshore oil and gas fields provide much information about the number of times,temperature,depth,time and phase state of oil-gas migration,as well as about the composition of organic inclusions.On the basis of the type,character,composition and distribution of organic inclusions in the Zhu-Ⅲ Depression at the Pearl River Mouth,information can be developed about the source rocks of oil and gas,and their evolution and migration.

  2. Review of the National Reduction Plan for NMVOM [Non-Methane Volatile Organic Materials]. Sectors industry, energy, TSG [trade, services and government] and building; Terugblik op het Nationaal Reductieplan NMVOS [Niet-Methaan Vluchtige Organische Stoffen]. Industrie, energie, HDO [handel, diensten en overheid] en bouw

    Energy Technology Data Exchange (ETDEWEB)

    Locht, G.

    2012-09-15

    The title project aims to reduce emissions of Volatile Organic Compounds (VOC) from several sectors in the period 2000-2010. This report is a review of the project and is based on the definitive data over these years in the Dutch Pollutant Release and Transfer Register (PRTR). Compared to the start of the NRP-NMVOS, there are now less instruments for environmental policy. There are more general binding environmental rules and less environmental permits. Furthermore, several agreements between governments and branches have ended. May 2012 the Gothenburg protocol was revised. It shows a VOC emission reduction for the Netherlands of 8% in 2020 compared to 2005. It is expected this will be achieved by means of the current policy and legislation [Dutch] Het titel project is opgesteld om de VOS-emissies van deze sectoren tereduceren. Het NRP-NMVOS heeft betrekking op de jaren 2000 tot en met 2010. Dit rapport is een terugblik op het project en gaat uit van de medio 2012 beschikbare definitieve emissiegegevens over al deze jaren. In vergelijking met de start van het NRP-NMVOS zijn er minder milieubeleidsinstrumenten. Er zijn meer algemene milieuregels en minder vergunningen en diverse convenanten tussen overheden en bedrijfsleven zijn afgelopen. In het herziene Gothenburg protocol van mei 2012 is voor Nederland voor 2020 en verder een NMVOS reductie van 8% ten opzichte van het 2005 niveau afgesproken. Het ligt in de verwachting dat dit gehaald gaat worden bij voortzetting van het huidige beleid en instrumentatie.

  3. Implications of changing urban and rural emissions on non-methane hydrocarbons in the Pearl River Delta region of China

    Science.gov (United States)

    Tang, J. H.; Chan, L. Y.; Chan, C. Y.; Li, Y. S.; Chang, C. C.; Wang, X. M.; Zou, S. C.; Barletta, Barbara; Blake, D. R.; Wu, Dui

    2008-05-01

    Guangzhou (GZ) is one of the highly industrialized and economically vibrant cities in China, yet it remains relatively understudied in terms of its air quality, which has become severely degraded. In this study, extensive air sampling campaigns had been conducted at GZ urban sites and in Dinghu Mountain (DM), a rural site, in the Pearl River Delta (PRD) during the spring of 2001 and 2005. Additionally, roadside and tunnel samples were collected in GZ in 2000 and 2005. Later, exhaust samples from liquefied petroleum gas (LPG)- and gasoline-fueled taxis were collected in 2006. All samples were analyzed for C2-C10 non-methane hydrocarbons (NMHCs). NMHC profiles showed significant differences in the exhaust samples between gasoline- and LPG-fueled taxis. Propane (47%) was the dominant hydrocarbon in the exhaust of the LPG-fueled taxis, while ethene (35%) was the dominant one in that of gasoline-fueled taxis. The use of LPG-fueled buses and taxis since 2003 and the leakage from these LPG-fueled vehicles were the major factors for the much higher level of propane in GZ urban area in 2005 compared to 2001. The mixing ratios of toluene, ethylbenzene, m/p-xylene and o-xylene decreased at the GZ and DM sites between 2001 and 2005, especially for toluene in GZ, despite the sharp increase in the number of registered motor vehicles in GZ. This phenomenon was driven in part by the closure of polluting industries as well as the upgrading of the road network in urban GZ and in part by the implementation of more stringent emission standards for polluting industries and motor vehicles in the PRD region.

  4. Non-methane hydrocarbons in the atmosphere of Mexico City: Results of the 2012 ozone-season campaign

    Science.gov (United States)

    Jaimes-Palomera, Mónica; Retama, Armando; Elias-Castro, Gabriel; Neria-Hernández, Angélica; Rivera-Hernández, Olivia; Velasco, Erik

    2016-05-01

    With the aim to strengthen the verification capabilities of the local air quality management, the air quality monitoring network of Mexico City has started the monitoring of selected non-methane hydrocarbons (NMHCs). Previous information on the NMHC characterization had been obtained through individual studies and comprehensive intensive field campaigns, in both cases restricted to sampling periods of short duration. This new initiative will address the NMHC pollution problem during longer monitoring periods and provide robust information to evaluate the effectiveness of new control measures. The article introduces the design of the monitoring network and presents results from the first campaign carried out during the first six months of 2012 covering the ozone-season (Mar-May). Using as reference data collected in 2003, results show reductions during the morning rush hour (6-9 h) in the mixing ratios of light alkanes associated with the consumption and distribution of liquefied petroleum gas and aromatic compounds related with the evaporation of fossil fuels and solvents, in contrast to olefins from vehicular traffic. The increase in mixing ratios of reactive olefins is of relevance to understand the moderate success in the ozone and fine aerosols abatement in recent years in comparison to other criteria pollutants. In the case of isoprene, the typical afternoon peak triggered by biogenic emissions was clearly observed for the first time within the city. The diurnal profiles of the monitored compounds are analyzed in terms of the energy balance throughout the day as a surrogate of the boundary layer evolution. Particular features of the diurnal profiles and correlation between individual NMHCs and carbon monoxide are used to investigate the influence of specific emission sources. The results discussed here highlight the importance of monitoring NMHCs to better understand the drivers and impacts of air pollution in large cities like Mexico City.

  5. ACTRIS non-methane hydrocarbon intercomparison experiment in Europe to support WMO-GAW and EMEP observation networks

    Directory of Open Access Journals (Sweden)

    C. C. Hoerger

    2014-10-01

    Full Text Available The performance of 20 European laboratories involved in long-term non-methane hydrocarbon (NMHC measurements within the framework of Global Atmosphere Watch (GAW and European Monitoring and Evaluation Programme (EMEP was assessed with respect to the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network and GAW data quality objectives (DQOs. Compared to previous intercomparisons the DQOs of ACTRIS are much more demanding with deviations to a reference value of less than 5% and repeatability of better than 2% for mole fractions above 0.1 nmol mol−1. The participants were asked to measure both a 30 component NMHC mixture in nitrogen (NMHC_N2 at approximately 1 nmol mol−1 and whole air (NMHC_air, following a standardised operation procedure including zero- and calibration gas measurements. Furthermore, they had to report details on their instruments and they were asked to assess measurement uncertainties. The NMHCs were analysed either by gas chromatography-flame ionisation detection or gas chromatography-mass spectrometer methods. Most systems performed well for the NMHC_N2 measurements (88% of the reported values were within the GAW DQOs and even 58% within the ACTRIS DQOs. For NMHC_air generally more frequent and larger deviations to the assigned values were observed compared to NMHC_N2 (77% of the reported values were within the GAW DQOs, but only 48% within the ACTRIS DQOs. Important contributors to the poorer performance in NMHC_air compared to NMHC_N2 were a more complex matrix and a larger span of NMHC mole fractions (0.03–2.5 nmol mol−1. Issues, which affected both NMHC mixtures, are the usage of direct vs. two-step calibration, breakthrough of C2–C3 hydrocarbons, blank values in zero-gas measurements (especially for those systems using a Nafion® Dryer, adsorptive losses of aromatic compounds, and insufficient chromatographic resolution. Essential for high-quality results are experienced operators, a

  6. Gas adsorption on metal-organic frameworks

    Science.gov (United States)

    Willis, Richard R [Cary, IL; Low, John J. , Faheem, Syed A.; Benin, Annabelle I [Oak Forest, IL; Snurr, Randall Q [Evanston, IL; Yazaydin, Ahmet Ozgur [Evanston, IL

    2012-07-24

    The present invention involves the use of certain metal organic frameworks that have been treated with water or another metal titrant in the storage of carbon dioxide. The capacity of these frameworks is significantly increased through this treatment.

  7. Metal organic frameworks for gas storage

    KAUST Repository

    Alezi, Dalal

    2016-06-09

    Embodiments provide a method of storing a compound using a metal organic framework (MOF). The method includes contacting one or more MOFs with a fluid and sorbing one or more compounds, such as O2 and CH4. O2 and CH4 can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF, wherein M can include aluminum, iron, gallium, indium, vanadium, chromium, titanium, or scandium.

  8. Hyperthin Organic Membranes for Gas Separations

    Science.gov (United States)

    Wang, Minghui

    Gas separation is practically important in many aspects, e.g., clean energy production and global warming prevention. Compared to other separation technologies like cryogenic distillation and pressure swing adsorption, membrane separation is considered to be more energy efficient. For practical purposes, the ultimate goal is to construct membranes producing high flux and high gas permeation selectivity at the same time. Based on the inverse relationship between flux and membrane thickness, it is clear that fabricating highly selective membranes as thin as possible could increase the flux through the membrane without sacrificing selectivity. But it has proven to be challenging to manufacture selective membranes in the hyperthin (poly(1-trimethylsilyl-1-propyne) (PTMSP), using Langmuir-Blodgett (LB) and Layer-by-Layer (LbL) deposition methods. A "gluing" strategy has been successfully introduced into LB films by our laboratory recently, in which LB monolayers are ionically crosslinked with polyelectrolytes. This success stimulated the pursuance of LB films with improved gas separation properties by: (i) examining calix[n]arene-based surfactants with different sizes (ii) using polymeric surfactants as LB forming materials, and (iii) optimizing the condition of the subphase containing polyelectrolytes. Both a strong polyelectrolyte poly(4-styrene sulfonate) (PSS) and a weak polyelectrolyte poly(acrylic acid) (PAA) were used to create glued LB bilayers. The gas permeation through PSS or PAA-glued LB bilayers made of calix[n]arenes was found to be dominated by solution-diffusion rather than molecular-sieving mechanism. The porous nature of calix[n]arene-based surfactants also turned out to be unnecessary for constructing LB films with high gas selectivities, because a single PAA-glued LB bilayer made of a nonporous polymeric surfactant (ca. 7 nm) was found to exhibit a much higher H2/CO2 selectivity (200), which reached the "upper bound". The key factors that are likely

  9. Organ protection by the noble gas helium

    NARCIS (Netherlands)

    Smit, K.F.

    2017-01-01

    The aims of this thesis were to investigate whether helium induces preconditioning in humans, and to elucidate the mechanisms behind this possible protection. First, we collected data regarding organ protective effects of noble gases in general, and of helium in particular (chapters 1-3). In chapter

  10. Draft Genome Sequence of Methylophaga muralis Bur 1, a Haloalkaliphilic (Non-Methane-Utilizing) Methylotroph Isolated from a Soda Lake

    Science.gov (United States)

    Trotsenko, Yuri A.; Shmareva, Maria N.; Tarlachkov, Sergey V.; Mustakhimov, Ildar I.

    2016-01-01

    The draft genome sequence of Methylophaga muralis strain Bur 1 (VKM B-3046T), a non-methane-utilizing methylotroph isolated from a soda lake, is reported here. Strain Bur 1 possesses genes for methanol and methylamine (methylamine dehydrogenase and N-methylglutamate pathway) oxidation. Genes for the biosynthesis of ectoine were also found. PMID:27811106

  11. Assessing methods to estimate emissions of non-methane organic compounds from landfills

    DEFF Research Database (Denmark)

    Saquing, Jovita M.; Chanton, Jeffrey P.; Yazdani, Ramin

    2014-01-01

    in estimating speciated NMOC flux from landfills; (2) determine for what types of landfills the ratio method may be in error and why, using recent field data to quantify the spatial variation of (CNMOCs/CCH4) in landfills; and (3) formulate alternative models for estimating NMOC emissions from landfills...

  12. Continuous organic waste digester and methane gas generator

    Energy Technology Data Exchange (ETDEWEB)

    Araneta, V.A.

    1979-01-01

    A patent on the construction of a utility model of an industrial product of a continuous organic-waste digester and methane-gas generator is described. It comprises an airtight chamber to receive slurry of organic waste; a gas-water scrubber to purge carbon dioxide, odor-omitting gases and froth or scrum from newly formed methane gas evolving from said slurry of organic wastes; and two dually functioning slurry-feed and -discharge pipes connected to a reversible pump. It has one pipe with an opening at the base of an airtight chamber and the other pipe with up-ended openings below the fluid level of the slurry to be accumulated in the airtight chamber.

  13. Separation of Organic Dyes from Water by Colloidal Gas Aphrons

    Institute of Scientific and Technical Information of China (English)

    黄颖怡; 王运东; 戴猷元

    2002-01-01

    Colloidal gas aphrons (CGAs) are micron-sized gas bubbles produced by stirring surfactant solutions at high speed. A single CGA dispersed in water is composed of a gaseous inner core, surrounded by a double water-soapy layer. CGAs have large interfacial area per unit volume and exhibit relatively high stability. These characteristics make CGAs very suitable in flotation systems. This paper studied the flotation of organic dyes from water using CGAs. The experimental results show that the flotation process may follow four mechanisms, i.e., ion coupling of the oppositely charged species of the surfactant forming the CGA and the organic dye, reactions between CGA and the organic dye, ion-dye complex adsorbed on the surface of CGAs, and hydrophilic or hydrophobic characteristics of the organic dyes.

  14. Seasonal and Diurnal Variations of Atmospheric Non-Methane Hydrocarbons in Guangzhou, China

    Directory of Open Access Journals (Sweden)

    Longfeng Li

    2012-05-01

    Full Text Available In recent decades, high ambient ozone concentrations have become one of the major regional air quality issues in the Pearl River Delta (PRD region. Non-methane hydrocarbons (NMHCs, as key precursors of ozone, were found to be the limiting factor in photochemical ozone formation for large areas in the PRD. For source apportioning of NMHCs as well as ozone pollution control strategies, it is necessary to obtain typical seasonal and diurnal patterns of NMHCs with a large pool of field data. To date, few studies have focused on seasonal and diurnal variations of NMHCs in urban areas of Guangzhou. This study explored the seasonal variations of most hydrocarbons concentrations with autumn maximum and spring minimum in Guangzhou. The diurnal variations of most anthropogenic NMHCs typically showed two-peak pattern with one at 8:00 in the morning and another at 20:00 in the evening, both corresponding to traffic rush hours in Guangzhou, whereas isoprene displayed a different bimodal diurnal curve. Propene, ethene, m, p-xylene and toluene were the four largest contributors to ozone formation in Guangzhou, based on the evaluation of individual NMHCs’ photochemical reactivity. Therefore, an effective strategy for controlling ozone pollution may be achieved by the reduction of vehicle emissions in Guangzhou.

  15. Tropospheric OH and Cl levels deduced from non-methane hydrocarbon measurements in a marine site

    Directory of Open Access Journals (Sweden)

    C. Arsene

    2007-09-01

    Full Text Available In situ continuous hourly measurements of C2–C8 non-methane hydrocarbons (NMHCS have been performed from March to October 2006 at two coastal locations (natural and rural on the island of Crete, in the Eastern Mediterranean. Well defined diel variations were observed for several short lived NMHCS (including ethene, propene, n-butane, n-pentane, n-hexane, 2-methyl-pentane. The daytime concentration of hydroxyl (OH radicals estimated from these experimental data varied from 1.3×106 to ~4.0×106 radical cm−3, in good agreement with box-model simulations. In addition the relative variability of various hydrocarbon pairs (at least 7 was used to derive the tropospheric levels of Cl atoms. The Cl atom concentration has been estimated to range between 0.6×104 and 4.7×104 atom cm−3, in good agreement with gaseous hydrochloric acid (HCl observations in the area. Such levels of Cl atoms can be of considerable importance for the oxidation capacity of the troposphere on a regional scale.

  16. Seasonal behavior of non-methane hydrocarbons in the firn air at Summit, Greenland

    Science.gov (United States)

    Helmig, D.; Stephens, C. R.; Caramore, J.; Hueber, J.

    2014-03-01

    Non-methane hydrocarbons (NMHC) were measured in the ambient air and in the snowpack interstitial firn air at ˜1 m depth continuously for nearly two years at Summit, Greenland, from fall 2008 through summer 2010. Additionally, five firn air depth profiles were conducted to a depth of 3 m spanning winter, spring, and summer seasons. Here we report measurements of ethane, ethene, ethyne, propane, propene, i-butane, n-butane, i-pentane, n-pentane, and benzene and discuss the seasonal behavior of these species in the ambient and firn air. The alkanes, ethyne, and benzene in the firn air closely reflect the ambient air concentrations during all the seasons of the year. In spring and summer seasons, ethene and propene were enhanced in the near-surface firn over that in the ambient air, indicating a photochemical production mechanism for these species within the snowpack interstitial air. Evaluation of the NMHC ratios of i-butane/n-butane, i-pentane/n-pentane, and benzene/ethyne in both ambient and firn air does not provide evidence for chlorine or bromine radical chemistry significantly affecting these gases, except in a few summer samples, where individual data points may suggest bromine oxidation influence.

  17. Estimates for biogenic non-methane hydrocarbons and nitric oxide emissions in the Valley of Mexico

    Science.gov (United States)

    Velasco, Erik

    Biogenic non-methane hydrocarbons (NMHC), 2-methyl-3-buten-2-ol (methylbutenol or MBO) and nitrogen oxide (NO) emissions were estimated for the Valley of Mexico developing a spatially and temporally resolved emission inventory for air quality models. The modeling domain includes all the Metropolitan Mexico City Area, the surrounding forests and agriculture fields. The estimates were based on several sources of land use and land cover data and a biogenic emission model; the biomass density and tree characteristics were obtained from reforestation program data. The biogenic emissions depend also on climatic conditions, mainly temperature and solar radiation. The temperature was obtained from a statistical revision of the last 10 yr data reported by the Mexico City Automatic Atmospheric Monitoring Network, while the solar radiation data were obtained from measurements performed in a typical oak forest in the Valley and from sources of total solar radiation data for Mexico City. The results indicated that 7% of total hydrocarbon emissions in Mexico Valley are due to vegetation and NO emissions from soil contribute with 1% to the total NO x emissions.

  18. Long term trends of methane, non methane hydrocarbons, and carbon monoxide in urban atmosphere.

    Science.gov (United States)

    Ahmed, Ezaz; Kim, Ki-Hyun; Jeon, Eui-Chan; Brown, Richard J C

    2015-06-15

    The concentrations of methane (CH4), non-methane hydrocarbons (NMHC), and carbon monoxide (CO) were measured at two urban locations (Guro (GR) and Nowon (NW)) in Seoul, Korea between 2004 and 2013. The mean amount fractions of CH4, NMHC, and CO, measured at GR over this period were 2.06±0.02, 0.32±0.03, and 0.61±0.05 ppm, respectively, while at NW they were 2.08±0.06, 0.33±0.05, and 0.54±0.06 ppm, respectively. The ratio of CH4 to the total hydrocarbon amount fraction remained constant across the study years: 0.82 to 0.90 at GR and 0.81 to 0.89 at NW. Similarly, stable ratios were also observed between NMHC and THC at the two sites. In contrast, the annual mean ratios for CH4/NMHC showed a larger variation: between 4.55 to 8.67 at GR and 4.25 to 8.45 at NW. The seasonality of CO was characterized by wintertime maxima, while for CH4 and NMHC the highest amount fractions were found in fall. The analysis of their long-term trends based on Mann-Kendall and Sen's methods showed an overall increase of THC and CH4, whereas a decreasing trend was observed for NMHC and CO.

  19. Biodigestor for organic waste gas; Biodigestor para o gas do lixo organico

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Carla Miranda; Fernandes, Carla Barbosa; Souza, Aline Vieira da Silva e; Melo, Cibelly Caroliny Santos; Sales, Jefferson Santos; Frade, Marcelo Lorenzo; Machado, Marcus Vinicius; Frade, Matheus Costa; Gomes, Natashua Lauar; Costa, Pedro Henrique de Andrade; Moraes, Rodrigo de Almeida; Estrella, Thales Goncalves; Lima, Miriam Cristina Pontello Barbosa [Centro Universitario de Belo Horizonte (UniBH), MG (Brazil)], e-mails: carlam.ferreira@yahoo.com.br, miriam.pontello@gmail.com

    2011-07-01

    This article to present an alternative reuse os the gas produced by garbage, through the construction of a digester, with a view to preserving the environment through renewable energy. The energy produced by this system is obtained from the decomposition of organic waste is biogas, made up of gases such as methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). This experiment verifies the possibility of using methane gas as an alternative to the operation of a domestic stove. (author)

  20. Organic Substances from Unconventional Oil and Gas Production in Shale

    Science.gov (United States)

    Orem, W. H.; Varonka, M.; Crosby, L.; Schell, T.; Bates, A.; Engle, M.

    2014-12-01

    Unconventional oil and gas (UOG) production has emerged as an important element in the US and world energy mix. Technological innovations in the oil and gas industry, especially horizontal drilling and hydraulic fracturing, allow for the enhanced release of oil and natural gas from shale compared to conventional oil and gas production. This has made commercial exploitation possible on a large scale. Although UOG is enormously successful, there is surprisingly little known about the effects of this technology on the targeted shale formation and on environmental impacts of oil and gas production at the surface. We examined water samples from both conventional and UOG shale wells to determine the composition, source and fate of organic substances present. Extraction of hydrocarbon from shale plays involves the creation and expansion of fractures through the hydraulic fracturing process. This process involves the injection of large volumes of a water-sand mix treated with organic and inorganic chemicals to assist the process and prop open the fractures created. Formation water from a well in the New Albany Shale that was not hydraulically fractured (no injected chemicals) had total organic carbon (TOC) levels that averaged 8 mg/L, and organic substances that included: long-chain fatty acids, alkanes, polycyclic aromatic hydrocarbons, heterocyclic compounds, alkyl benzenes, and alkyl phenols. In contrast, water from UOG production in the Marcellus Shale had TOC levels as high as 5,500 mg/L, and contained a range of organic chemicals including, solvents, biocides, scale inhibitors, and other organic chemicals at thousands of μg/L for individual compounds. These chemicals and TOC decreased rapidly over the first 20 days of water recovery as injected fluids were recovered, but residual organic compounds (some naturally-occurring) remained up to 250 days after the start of water recovery (TOC 10-30 mg/L). Results show how hydraulic fracturing changes the organic

  1. Crystallographic studies of gas sorption in metal–organic frameworks

    Science.gov (United States)

    Carrington, Elliot J.; Vitórica-Yrezábal, Iñigo J.; Brammer, Lee

    2014-01-01

    Metal–organic frameworks (MOFs) are a class of porous crystalline materials of modular design. One of the primary applications of these materials is in the adsorption and separation of gases, with potential benefits to the energy, transport and medical sectors. In situ crystallography of MOFs under gas atmospheres has enabled the behaviour of the frameworks under gas loading to be investigated and has established the precise location of adsorbed gas molecules in a significant number of MOFs. This article reviews progress in such crystallographic studies, which has taken place over the past decade, but has its origins in earlier studies of zeolites, clathrates etc. The review considers studies by single-crystal or powder diffraction using either X-rays or neutrons. Features of MOFs that strongly affect gas sorption behaviour are discussed in the context of in situ crystallographic studies, specifically framework flexibility, and the presence of (organic) functional groups and unsaturated (open) metal sites within pores that can form specific interactions with gas molecules. PMID:24892587

  2. Selective gas adsorption and separation in metal-organic frameworks.

    Science.gov (United States)

    Li, Jian-Rong; Kuppler, Ryan J; Zhou, Hong-Cai

    2009-05-01

    Adsorptive separation is very important in industry. Generally, the process uses porous solid materials such as zeolites, activated carbons, or silica gels as adsorbents. With an ever increasing need for a more efficient, energy-saving, and environmentally benign procedure for gas separation, adsorbents with tailored structures and tunable surface properties must be found. Metal-organic frameworks (MOFs), constructed by metal-containing nodes connected by organic bridges, are such a new type of porous materials. They are promising candidates as adsorbents for gas separations due to their large surface areas, adjustable pore sizes and controllable properties, as well as acceptable thermal stability. This critical review starts with a brief introduction to gas separation and purification based on selective adsorption, followed by a review of gas selective adsorption in rigid and flexible MOFs. Based on possible mechanisms, selective adsorptions observed in MOFs are classified, and primary relationships between adsorption properties and framework features are analyzed. As a specific example of tailor-made MOFs, mesh-adjustable molecular sieves are emphasized and the underlying working mechanism elucidated. In addition to the experimental aspect, theoretical investigations from adsorption equilibrium to diffusion dynamics via molecular simulations are also briefly reviewed. Furthermore, gas separations in MOFs, including the molecular sieving effect, kinetic separation, the quantum sieving effect for H2/D2 separation, and MOF-based membranes are also summarized (227 references).

  3. A five year record of high-frequency in situ measurements of non-methane hydrocarbons at Mace Head, Ireland

    Directory of Open Access Journals (Sweden)

    A. Grant

    2011-02-01

    Full Text Available Continuous high-frequency in situ measurements of a range of non-methane hydrocarbons have been made at Mace Head since January 2005. Mace Head is a background Northern Hemispheric site situated on the eastern edge of the Atlantic. Five year measurements (2005–2009 of eleven non-methane hydrocarbons, namely C2–C5 alkanes, benzene, toluene, ethyl-benzene and the xylenes, have been separated into baseline Northern Hemispheric and European polluted air masses, among other sectors. Seasonal cycles in baseline Northern Hemispheric air masses and European polluted air masses arriving at Mace Head have been studied. Baseline air masses show a broad summer minima between June and September for shorter lived species, longer lived species show summer minima in July/August. All species displayed a winter maxima in February. European air masses showed baseline elevated mole fractions for all non-methane hydrocarbons, largest elevations (of up to 360 ppt for ethane maxima from baseline data were observed in winter maxima, with smaller elevations observed during the summer. Analysis of temporal trends using the Mann-Kendall test showed small (<6%/year but statistically significant decreases in the butanes, i-pentane and o-xylene between 2005 and 2009 in European air. Toluene was found to have an increasing trend of 34%/year in European air. No significant trends were found for any species in baseline air.

  4. Installation for the recovery of methane gas from organic waste

    Energy Technology Data Exchange (ETDEWEB)

    Pfefferkorn, H.

    1981-11-24

    The invention relates to an installation for the recovery of methane gas from organic waste with a fermentation space, a gas collecting space and a post-fermentation space, as well as with at least one supply line into the fermentation space and one offtake for the excess, fermented liquid from the post-fermentation space, the spaces being heat-insulated and preferably embedded at least partially in the ground, and the post-fermentation space, which preferably is arranged above the fermentation space, being connected in the manner of communicating vessels with the fermentation space, preferably in one structural unit.

  5. Analysis of non-methane hydrocarbons in air samples collected aboard the CARIBIC passenger aircraft

    Directory of Open Access Journals (Sweden)

    A. K. Baker

    2009-10-01

    Full Text Available The CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container is a long-term monitoring program making regular atmospheric measurements from an instrument container installed monthly aboard a passenger aircraft. Typical cruising altitudes of the aircraft allow for the study of the free troposphere and the extra-tropical upper troposphere as well as the lowermost stratosphere. CARIBIC measurements include a number of real time analyses as well as the collection of aerosol and whole air samples. These whole air samples are analyzed post-flight for a suite of trace gases, which includes non-methane hydrocarbons (NMHC.

    The NMHC measurement system and its analytical performance are described here. Precision was found to vary slightly by compound, and is less than 2% for the C2–C6 alkanes and ethyne, and between 1 and 6% for C7–C8 alkanes and aromatic compounds. Preliminary results from participation in a Global Atmospheric Watch (WMO VOC audit indicate accuracies within the precision of the system. Limits of detection are 1 pptv for most compounds, and up to 3 pptv for some aromatics. These are sufficiently low to measure mixing ratios typically observed in the upper troposphere and lowermost stratosphere for the longer-lived NMHC, however, in air samples from these regions many of the compounds with shorter lifetimes (<5 d were frequently below the detection limit. Observed NMHC concentrations span many orders of magnitude, dependent on atmospheric region and air mass history, with concentrations typically decreasing with shorter chemical lifetimes.

  6. A survey of carbon monoxide and non-methane hydrocarbons in the Arctic Ocean during summer 2010

    Directory of Open Access Journals (Sweden)

    S. Tran

    2013-03-01

    Full Text Available During the ARK XXV 1 + 2 expedition in the Arctic Ocean carried out in June–July 2010 aboard the R/V Polarstern, we measured carbon monoxide (CO, non-methane hydrocarbons (NMHC and phytoplankton pigments at the sea surface and down to a depth of 100 m. The CO and NMHC sea-surface concentrations were highly variable; CO, propene and isoprene levels ranged from 0.6 to 17.5 nmol L−1, 1 to 322 pmol L−1 and 1 to 541 pmol L−1, respectively. The CO and alkene concentrations as well as their sea–air fluxes were enhanced in polar waters off of Greenland, which were more stratified because of ice melting and richer in chromophoric dissolved organic matter (CDOM than typical North Atlantic waters. The spatial distribution of the surface concentrations of CO was consistent with our current understanding of CO-induced UV photoproduction in the sea. The vertical distributions of the CO and alkenes were comparable and followed the trend of light penetration, with the concentrations displaying a relatively regular exponential decrease down to non-measurable values below 50 m. However, no diurnal variations of CO or alkene concentrations were observed in the stratified and irradiated surface layers. On several occasions, we observed the existence of subsurface CO maxima at the level of the deep chlorophyll maximum. This finding suggests the existence of a non-photochemical CO production pathway, most likely of phytoplanktonic origin. The corresponding production rates normalized to the chlorophyll content were in the range of those estimated from laboratory experiments. In general, the vertical distributions of isoprene followed that of the phytoplankton biomass. These data support the existence of a dominant photochemical source of CO and light alkenes enhanced in polar waters of the Arctic Ocean, with a minor contribution of a biological source of CO. The biological source of isoprene is observed in the different water masses but significantly

  7. Gas-liquid chromatography in lunar organic analysis.

    Science.gov (United States)

    Gehrke, C. W.

    1972-01-01

    Gas-liquid chromatography (GLC) is a powerful and sensitive method for the separation and detection of organic compounds at nanogram levels. The primary requirement for successful analyses is that the compounds of interest must be volatile under the chromatographic conditions employed. Nonvolatile organic compounds must be converted to volatile derivatives prior to analysis. The derivatives of choice must be both amenable to chromatographic separation and be relatively stable. The condition of volatility necessitates the development of efficient derivatization reactions for important groups of compounds as amino acids, carbohydrates, nucleosides, etc. Trimethylsilylation and trifluoroacetylation represent specific areas of recent prominence. Some relevant practical aspects of GLC are discussed.

  8. Greenhouse gas emission factors associated with rewetting of organic soils

    Directory of Open Access Journals (Sweden)

    D. Wilson

    2016-04-01

    Full Text Available Drained organic soils are a significant source of greenhouse gas (GHG emissions to the atmosphere. Rewetting these soils may reduce GHG emissions and could also create suitable conditions for return of the carbon (C sink function characteristic of undrained organic soils. In this article we expand on the work relating to rewetted organic soils that was carried out for the 2014 Intergovernmental Panel on Climate Change (IPCC Wetlands Supplement. We describe the methods and scientific approach used to derive the Tier 1 emission factors (the rate of emission per unit of activity for the full suite of GHG and waterborne C fluxes associated with rewetting of organic soils. We recorded a total of 352 GHG and waterborne annual flux data points from an extensive literature search and these were disaggregated by flux type (i.e. CO2, CH4, N2O and DOC, climate zone and nutrient status. Our results showed fundamental differences between the GHG dynamics of drained and rewetted organic soils and, based on the 100 year global warming potential of each gas, indicated that rewetting of drained organic soils leads to: net annual removals of CO2 in the majority of organic soil classes; an increase in annual CH4 emissions; a decrease in N2O and DOC losses; and a lowering of net GHG emissions. Data published since the Wetlands Supplement (n = 58 generally support our derivations. Significant data gaps exist, particularly with regard to tropical organic soils, DOC and N2O. We propose that the uncertainty associated with our derivations could be significantly reduced by the development of country specific emission factors that could in turn be disaggregated by factors such as vegetation composition, water table level, time since rewetting and previous land use history.

  9. Organic peroxides' gas-particle partitioning and rapid heterogeneous decomposition on secondary organic aerosol

    Science.gov (United States)

    Li, Huan; Chen, Zhongming; Huang, Liubin; Huang, Dao

    2016-02-01

    Organic peroxides, important species in the atmosphere, promote secondary organic aerosol (SOA) aging, affect HOx radicals cycling, and cause adverse health effects. However, the formation, gas-particle partitioning, and evolution of organic peroxides are complicated and still unclear. In this study, we investigated in the laboratory the production and gas-particle partitioning of peroxides from the ozonolysis of α-pinene, which is one of the major biogenic volatile organic compounds in the atmosphere and an important precursor for SOA at a global scale. We have determined the molar yields of hydrogen peroxide (H2O2), hydromethyl hydroperoxide (HMHP), peroxyformic acid (PFA), peroxyacetic acid (PAA), and total peroxides (TPOs, including unknown peroxides) and the fraction of peroxides in α-pinene/O3 SOA. Comparing the gas-phase peroxides with the particle-phase peroxides, we find that gas-particle partitioning coefficients of PFA and PAA are 104 times higher than the values from the theoretical prediction, indicating that organic peroxides play a more important role in SOA formation than previously expected. Here, the partitioning coefficients of TPO were determined to be as high as (2-3) × 10-4 m3 µg-1. Even so, more than 80 % of the peroxides formed in the reaction remain in the gas phase. Water changes the distribution of gaseous peroxides, while it does not affect the total amount of peroxides in either the gas or the particle phase. Approx. 18 % of gaseous peroxides undergo rapid heterogeneous decomposition on SOA particles in the presence of water vapor, resulting in the additional production of H2O2. This process can partially explain the unexpectedly high H2O2 yields under wet conditions. Transformation of organic peroxides to H2O2 also preserves OH in the atmosphere, helping to improve the understanding of OH cycling.

  10. Analysis of Discharged Gas from Incinerator using Simulated Organic Solution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seungil; Kim, Hyunki; Heo, Jun; Kang, Dukwon [HaJI Co., Ltd., Radiation Eng. Center, Siheung (Korea, Republic of); Kim, Yunbok; Kwon, Youngbock [KORAD, Daejeon (Korea, Republic of)

    2014-05-15

    is controlled from 800 .deg. c to 930 .deg. C using temperature controller. The concentration of gaseous pollutants released by incinerating simulated organic waste is satisfied with Clean Air Conservation Act, Notification of Nuclear Safety Commission, Persistent Organic Pollutants Control Act and related statute. The incinerator used in this experiment is not object of regulation but the concentration of dioxin released from incinerator, 0.007ng-TEQ/Sm{sup 3}, could be ignored because it is just 7%, in comparison with the limit of exhaust standard, 0.1ng-TEQ/Sm{sup 3}. This is due to the rapid cooling of exhaust gas using heat-exchanger.

  11. Tholins - Organic chemistry of interstellar grains and gas

    Science.gov (United States)

    Sagan, C.; Khare, B. N.

    1979-01-01

    The paper discusses tholins, defined as complex organic solids formed by the interaction of energy - for example, UV light or spark discharge - with various mixtures of cosmically abundant gases - CH4, C2H6, NH3, H2O, HCHO, and H2S. It is suggested that tholins occur in the interstellar medium and are responsible for some of the properties of the interstellar grains and gas. Additional occurrences of tholins are considered. Tholins have been produced experimentally; 50 or so pyrolytic fragments of the brown, sometimes sticky substances have been identified by gas chromatography-mass spectrometry, and the incidence of these fragments in tholins produced by different procedures is reported.

  12. Biogenic non-methane hydrocarbons (NMHC). Nature`s contribution to regional and global atmospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Klockow, D.; Hoffman, T. [Inst. of Spectrochemistry and Applied Spectroscopy, Dortmund (Germany)

    1995-12-31

    Terrestrial vegetation provides an important source of volatile hydrocarbons, especially isoprene, monoterpenes and in addition possibly sesquiterpenes as well as oxygenated compounds. Although there exist considerable uncertainties in the estimation of the magnitude of these biogenic NMHC emissions, it is generally accepted that the majority of global NMHC release is from natural and not from anthropogenic sources. Taking into consideration the high reactivity of the mostly unsaturated biogenic emissions, their impact on tropospheric processes can be assumed to be of great importance. Together with anthropogenic NO{sub x} emissions, the highly reactive natural alkenes can act as precursors in photochemical oxidant formation and contribute to regional-scale air pollution. Their oxidation in the atmosphere and the subsequent gas-to-particle conversion of the products lead to the formation of organic aerosols. Because of the formation of phytotoxic compounds, the interaction of the biogenic hydrocarbons with ozone inside or outside the leaves and needles of plants has been suggested to play a role in forest decline. (author)

  13. Organic compounds in produced waters from shale gas wells.

    Science.gov (United States)

    Maguire-Boyle, Samuel J; Barron, Andrew R

    2014-01-01

    A detailed analysis is reported of the organic composition of produced water samples from typical shale gas wells in the Marcellus (PA), Eagle Ford (TX), and Barnett (NM) formations. The quality of shale gas produced (and frac flowback) waters is a current environmental concern and disposal problem for producers. Re-use of produced water for hydraulic fracturing is being encouraged; however, knowledge of the organic impurities is important in determining the method of treatment. The metal content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Mineral elements are expected depending on the reservoir geology and salts used in hydraulic fracturing; however, significant levels of other transition metals and heavier main group elements are observed. The presence of scaling elements (Ca and Ba) is related to the pH of the water rather than total dissolved solids (TDS). Using gas chromatography mass spectrometry (GC/MS) analysis of the chloroform extracts of the produced water samples, a plethora of organic compounds were identified. In each water sample, the majority of organics are saturated (aliphatic), and only a small fraction comes under aromatic, resin, and asphaltene categories. Unlike coalbed methane produced water it appears that shale oil/gas produced water does not contain significant quantities of polyaromatic hydrocarbons reducing the potential health hazard. Marcellus and Barnett produced waters contain predominantly C6-C16 hydrocarbons, while the Eagle Ford produced water shows the highest concentration in the C17-C30 range. The structures of the saturated hydrocarbons identified generally follows the trend of linear > branched > cyclic. Heterocyclic compounds are identified with the largest fraction being fatty alcohols, esters, and ethers. However, the presence of various fatty acid phthalate esters in the Barnett and Marcellus produced waters can be related to their use in drilling fluids and breaker additives

  14. Seasonal variability of atmospheric nitrogen oxides and non-methane hydrocarbons at the GEOSummit station, Greenland

    Directory of Open Access Journals (Sweden)

    L. J. Kramer

    2014-05-01

    Full Text Available Measurements of atmospheric NOx (NOx = NO + NO2, peroxyacetyl nitrate (PAN, NOy and non-methane hydrocarbons (NMHC were taken at the GEOSummit Station, Greenland (72.34° N, 38.29° W, 3212 m.a.s.l from July 2008 to July 2010. The data set represents the first year-round concurrent record of these compounds sampled at a high latitude Arctic site in the free troposphere. Here, the study focused on the seasonal variability of these important ozone (O3 precursors in the Arctic free troposphere and the impact from transported anthropogenic and biomass burning emissions. Our analysis shows that PAN is the dominant NOy species in all seasons at Summit, varying from 49% to 78%, however, we find that odd NOy species (odd NOy = NOy − PAN-NOx contribute a large amount to the total NOy speciation with monthly means of up to 95 pmol mol−1 in the winter and ∼40 pmol mol−1 in the summer, and that the level of odd NOy species at Summit during summer is greater than that of NOx. We hypothesize that the source of this odd NOy is most likely alkyl nitrates from transported pollution, and photochemically produced species such as HNO3 and HONO. FLEXPART retroplume analysis and tracers for anthropogenic and biomass burning emissions, were used to identify periods when the site was impacted by polluted air masses. Europe contributed the largest source of anthropogenic emissions during the winter and spring months, with up to 82% of the simulated anthropogenic black carbon originating from this region between December 2009 and March 2010, whereas, North America was the primary source of biomass burning emissions. Polluted air masses were typically aged, with median transport times to the site from the source region of 11 days for anthropogenic events in winter, and 14 days for BB plumes. Overall we find that the transport of polluted air masses to the high altitude Arctic typically resulted in high variability in levels of O3 and O3 precursors. During winter

  15. Organic Membranes for Selectivity Enhancement of Metal Oxide Gas Sensors

    Directory of Open Access Journals (Sweden)

    Thorsten Graunke

    2016-01-01

    Full Text Available We present the characterization of organic polyolefin and thermoplastic membranes for the enhancement of the selectivity of metal oxide (MOX gas sensors. The experimental study is done based on theoretical considerations of the membrane characteristics. Through a broad screening of dense symmetric homo- and copolymers with different functional groups, the intrinsic properties such as the mobility or the transport of gases through the matrix were examined in detail. A subset of application-relevant gases was chosen for the experimental part of the study: H2, CH4, CO, CO2, NO2, ethanol, acetone, acetaldehyde, and water vapor. The gases have similar kinetic diameters and are therefore difficult to separate but have different functional groups and polarity. The concentration of the gases was based on the international indicative limit values (TWA, STEL. From the results, a simple relationship was to be found to estimate the permeability of various polar and nonpolar gases through gas permeation (GP membranes. We used a broadband metal oxide gas sensor with a sensitive layer made of tin oxide with palladium catalyst (SnO2:Pd. Our aim was to develop a low-cost symmetrical dense polymer membrane to selectively detect gases with a MOX sensor.

  16. Geochemical investigation of the potential for mobilizing non-methane hydrocarbons during carbon dioxide storage in deep coal beds

    Science.gov (United States)

    Kolak, J.J.; Burruss, R.C.

    2006-01-01

    Coal samples of different rank (lignite to anthracite) were extracted in the laboratory with supercritical CO2 (40 ??C; 10 MPa) to evaluate the potential for mobilizing non-methane hydrocarbons during CO2 storage (sequestration) or enhanced coal bed methane recovery from deep (???1-km depth) coal beds. The total measured alkane concentrations mobilized from the coal samples ranged from 3.0 to 64 g tonne-1 of dry coal. The highest alkane concentration was measured in the lignite sample extract; the lowest was measured in the anthracite sample extract. Substantial concentrations of polycyclic aromatic hydrocarbons (PAHs) were also mobilized from these samples: 3.1 - 91 g tonne-1 of dry coal. The greatest amounts of PAHs were mobilized from the high-volatile bituminous coal samples. The distributions of aliphatic and aromatic hydrocarbons mobilized from the coal samples also varied with rank. In general, these variations mimicked the chemical changes that occur with increasing degrees of coalification and thermal maturation. For example, the amount of PAHs mobilized from coal samples paralleled the general trend of bitumen formation with increasing coal rank. The coal samples yielded hydrocarbons during consecutive extractions with supercritical CO2, although the amount of hydrocarbons mobilized declined with each successive extraction. These results demonstrate that the potential for supercritical CO2 to mobilize non-methane hydrocarbons from coal beds, and the effect of coal rank on this process, are important to consider when evaluating deep coal beds for CO2 storage.

  17. Capture and release of acid-gasses with acid-gas binding organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Heldebrant, David J; Yonker, Clement R; Koech, Phillip K

    2015-03-17

    A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

  18. Organic farmers may gain from Green House Gas trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    2009-01-01

    Farmers may earn money from participating in the ongoing greenhouse gas (GHG) trade system under the Kyoto agreement.......Farmers may earn money from participating in the ongoing greenhouse gas (GHG) trade system under the Kyoto agreement....

  19. Organic farmers may gain from Green House Gas trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    2009-01-01

    Farmers may earn money from participating in the ongoing greenhouse gas (GHG) trade system under the Kyoto agreement.......Farmers may earn money from participating in the ongoing greenhouse gas (GHG) trade system under the Kyoto agreement....

  20. Method of monitoring photoactive organic molecules in-situ during gas-phase deposition of the photoactive organic molecules

    Science.gov (United States)

    Forrest, Stephen R.; Vartanian, Garen; Rolin, Cedric

    2015-06-23

    A method for in-situ monitoring of gas-phase photoactive organic molecules in real time while depositing a film of the photoactive organic molecules on a substrate in a processing chamber for depositing the film includes irradiating the gas-phase photoactive organic molecules in the processing chamber with a radiation from a radiation source in-situ while depositing the film of the one or more organic materials and measuring the intensity of the resulting photoluminescence emission from the organic material. One or more processing parameters associated with the deposition process can be determined from the photoluminescence intensity data in real time providing useful feedback on the deposition process.

  1. Anthropogenic non-methane volatile hydrocarbons at Mt. Cimone (2165 m a.s.l., Italy): Impact of sources and transport on atmospheric composition

    Science.gov (United States)

    Lo Vullo, Eleonora; Furlani, Francesco; Arduini, Jgor; Giostra, Umberto; Graziosi, Francesco; Cristofanelli, Paolo; Williams, Martin L.; Maione, Michela

    2016-09-01

    To advance our understanding of the factors that affect pollution in mountainous areas, long-term, high frequency measurements of thirteen Non Methane Volatile Organic Compounds (NMVOCs) have been carried out at the atmospheric observatory on the top of Mt. Cimone (2165 m a.s.l.), whose location is ideal for sampling both aged air masses representing the regional background and polluted air masses coming from nearby sources of anthropogenic pollution. An analysis of the NMVOC time series available at Mt. Cimone during 2010-2014 was used to examine the influence of transport processes on NMVOC atmospheric composition and to derive information on the emission sources. We performed a multifactor principal component analysis whose results allowed us to identify the source categories emitting the NMVOCs measured at Mt. Cimone as well as to assess transport ranges in winter and summer. Aged air masses, due to long-range transport and related to vehicular traffic exhaust emissions accounted for 78% of the NMVOC variability in winter and 62% in summer, whereas evaporative emissions, likely to be associated with fresh emissions from nearby sources, accounted for 12% of the NMVOC variability and 24% in winter and summer, respectively. Such results have been confirmed by a further analysis in which the NMVOC variability as a function of their atmospheric lifetimes has been evaluated. The ratios of alkane isomers potentially provides a metric to investigate seasonal changes in NMVOCs composition and in the emission fields of butanes and pentanes, suggesting that during the summer the butanes are originating mainly from the European domain and that for pentanes non-anthropogenic sources may be contributing to the measured concentrations.

  2. Adsorption of two gas molecules at a single metal site in a metal–organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Run; #269; evski, Tom; #269; e; Kapelewski, Matthew T.; Torres-Gavosto, Rodolfo M.; Tarver, Jacob D.; Brown, Craig M.; Long, Jeffrey R. (LBNL); (Delaware); (UCB); (NIST)

    2016-11-21

    One strategy to markedly increase the gas storage capacity of metal–organic frameworks is to introduce coordinatively-unsaturated metal centers capable of binding multiple gas molecules. Herein, we provide an initial demonstration that a single metal site within a framework can support the terminal coordination of two gas molecules—specifically hydrogen, methane, or carbon dioxide.

  3. Adsorption of two gas molecules at a single metal site in a metal–organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Runčevski, Tomče; Kapelewski, Matthew T.; Torres-Gavosto, Rodolfo M.; Tarver, Jacob D.; Brown, Craig M.; Long, Jeffrey R.

    2016-01-01

    One strategy to markedly increase the gas storage capacity of metal-organic frameworks is to introduce coordinatively-unsaturated metal centers capable of binding multiple gas molecules. Herein, we provide an initial demonstration that a single metal site within a framework can support the terminal coordination of two gas molecules--specifically hydrogen, methane, or carbon dioxide.

  4. Internal mixing of the organic aerosol by gas phase diffusion of semivolatile organic compounds

    Directory of Open Access Journals (Sweden)

    C. Marcolli

    2004-01-01

    Full Text Available This paper shows that most of the so far identified constituents of the tropospheric organic particulate matter belong to a semivolatile fraction for which gas phase diffusion in the lower troposphere is sufficiently fast to establish thermodynamic equilibrium between aerosol particles. For the first time analytical expressions for this process are derived. Inspection of vapor pressure data of a series of organic substances allows a rough estimate for which substances this mixing process must be considered. As general benchmarks we conclude that for typical aerosol radii between 0.1 and 1 µm this mixing process is efficient at 25°C for polar species with molecular weights up to 200 and for non-polar species up to 320. At −10°C, these values are shifted to 150 for polar and to 270 for non-polar substances. The extent of mixing of this semivolatile fraction is governed by equilibrium thermodynamics, leading to a selectively, though not completely, internally mixed aerosol. The internal mixing leads to a systematic depression of melting and deliquescence points of organic and mixed organic/inorganic aerosols, thus leading to an aerosol population in the lower troposphere which is predominantly liquid.

  5. 49 CFR 173.334 - Organic phosphates mixed with compressed gas.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Organic phosphates mixed with compressed gas. 173... phosphates mixed with compressed gas. Hexaethyl tetraphosphate, parathion, tetraethyl dithio pyrophosphate, tetraethyl pyrophosphate, or other Division 6.1 organic phosphates (including a compound or mixture), may...

  6. Carbon dioxide capture and use: organic synthesis using carbon dioxide from exhaust gas.

    Science.gov (United States)

    Kim, Seung Hyo; Kim, Kwang Hee; Hong, Soon Hyeok

    2014-01-13

    A carbon capture and use (CCU) strategy was applied to organic synthesis. Carbon dioxide (CO2) captured directly from exhaust gas was used for organic transformations as efficiently as hyper-pure CO2 gas from a commercial source, even for highly air- and moisture-sensitive reactions. The CO2 capturing aqueous ethanolamine solution could be recycled continuously without any diminished reaction efficiency.

  7. Studies of gas adsorption in flexible Metal-Organic frameworks

    Science.gov (United States)

    Sircar, Sarmishtha

    Flexible Metal-Organic frameworks that exhibit a gate-opening (GO) adsorption mechanism have potential for gas separations and gas storage. The GO phenomenon occurs when molecular gates in the structure expand/contract in response to the activation/de-activation of a system variable e.g. temperature, pressure or gas. Sharp discontinuities in the isotherm leading to S-shapes and large adsorption-desorption hysteresis are typical of this phenomenon. This study investigates the kinetics and thermodynamics of the GO behavior by combining adsorption measurements and analytical modeling of adsorption kinetics and capacity as a function of adsorbate, GO pressure, and temperature. Basic understanding of GO mechanism will help harness GO-MOF's as adsorbents for gas separations and storage. Experiments were performed on two precharacterized MOFs with verified GO behavior. These are (1) Zn2(bpdc)2(bpee), which expands from a relative amorphous to crystalline structure and (2) Cu[(dhbc) 2(4,4f-bpy)]H2O, a mutually interdigitated 2-D structure (bpdc = biphenyldicarboxylate, bpee = 1,2]bipyridylethene; DMF = N,N-dimethyl formamide, dhbc= 2,5-dihydroxybenzoic acid, bpy=bipyridine). Both sub- and super-critical adsorption data were collected using three adsorption units: a standard low-pressure volumetric adsorption unit, a commercial high-pressure gravimetric analyzer and a custom-built high-pressure differential volumetric unit. Collected laboratory data were combined with published adsorption rate and isotherm data for analysis to broaden the range of data collection. The accuracy of the high-pressure differential unit was improved by over 300-fold by changing analytical methods of processing data to establish a reliable null correction. A pronounced effect of the allowed experimental time was found at cryogenic temperatures on (1). Tightening the stability criteria used by the adsorption equipment to determine equilibration increased the experimental time from the order of

  8. Non-methane biogenic volatile organic compound emissions from boreal peatland microcosms under warming and water table drawdown

    DEFF Research Database (Denmark)

    Faubert, P; Tiiva, P; Nakam, TA

    2011-01-01

    BVOC groups. Only isoprene emission was significantly increased by warming, parallel to the increased leaf number of the dominant sedge Eriophorum vaginatum. BVOC emissions from peat soil were higher under the control and warming treatments than water table drawdown, suggesting an increased activity...... assessed the combined effect of warming and water table drawdown on the BVOC emissions from boreal peatland microcosms. We also assessed the treatment effects on the BVOC emissions from the peat soil after the 7-week long experiment. Emissions of isoprene, monoterpenes, sesquiterpenes, other reactive VOCs...... and other VOCs were sampled using a conventional chamber technique, collected on adsorbent and analyzed by GC–MS. Carbon emitted as BVOCs was less than 1% of the CO2 uptake and up to 3% of CH4 emission. Water table drawdown surpassed the direct warming effect and significantly decreased the emissions of all...

  9. Gas Permeation Properties of Organic-inorganic Ultrathin Membranes

    Institute of Scientific and Technical Information of China (English)

    H. Kawakami

    2005-01-01

    @@ 1Introduction Recently, a great interest has been noted in the synthesis of inorganic membranes for gas separation. One of the candidates is a carbon molecular sieve (CMS) membrane, which is synthesized by the pyrolysis of a polymer. However, CMS membranes are very brittle and fragile. Additionally, it requires more careful handling and it is very difficult to prepare a thin CMS membrane because of its poor mechanical property. Therefore, the gas permeances of CMS membranes were not very high.

  10. A new mode of organization for the French gas industry; Vers la nouvelle organisation gaziere francaise

    Energy Technology Data Exchange (ETDEWEB)

    Pierret, Ch. [Ministere de l' Industrie et de la Recherche, 75 - Paris (France)

    1999-07-01

    It was not only traditional, but also highly topical for the government representative, Christian Perret, junior industry minister, to address delegates at the opening session of the 116. Gas Conference in Nancy. Indeed, a white paper has recently been published on the future organization of the French gas industry prior to implementation of the European gas directive. His recorded speech was shown on a video watched attentively by all delegates. (authors)

  11. CARIBIC observations of greenhouse gases and non-methane hydrocarbons on flights between Germany and South Africa

    Science.gov (United States)

    Brenninkmeijer, C. A.; Schuck, T. J.; Baker, A. K.; van Velthoven, P.

    2012-12-01

    Since May 2005 the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container, www.caribic-atmospheric.com) has made near-monthly deployments of an atmospheric observatory making measurements from aboard a Lufthansa Airbus A340-600 during routine passenger flights. Flights originate in Frankfurt, Germany and serve a large number of destinations, among them Cape Town and Johannesburg in South Africa. On these flights, which took place primarily during northern hemisphere winter 2010/2011, a near-meridional profile was obtained over Europe and Africa, in similar fashion to HIPPO flight tracks over the Pacific, be it without vertical profiles. Over Central Africa, deep convection transports boundary layer air to the free troposphere, linking observations at cruise altitude to surface emissions and allowing for the investigation of emissions and sources of atmospherically relevant species in Africa. Mixing ratios of greenhouse gases (methane, carbon dioxide, sulfur hexafluoride and nitrous oxide) and a suite of C2-C8 non-methane hydrocarbons (NMHC) are measured from flask samples collected at cruise altitude during flight. Several tracers, for example methane, carbon monoxide, and various NMHC, exhibit enhanced mixing ratios over tropical Africa. Using tracer-tracer correlations to characterize methane emissions from Africa, we find that biomass burning made a major contribution to the methane burden, but that also biogenic sources, such as wetlands, play a significant role. We also compare these measurements to those conducted earlier over India, which were used to investigate sources and emissions of greenhouse gases during the South Asian summer monsoon.

  12. A survey of carbon monoxide and non-methane hydrocarbons in the Arctic Ocean during summer 2010: assessment of the role of phytoplankton

    Directory of Open Access Journals (Sweden)

    S. Tran

    2012-04-01

    Full Text Available During the ARK XXV 1+2 expedition in the Arctic Ocean carried out in June–July 2010 aboard the R/V Polarstern, we measured carbon monoxide (CO, non-methane hydrocarbons (NMHC and phytoplankton pigments at the sea surface and down to a depth of 100 m. The CO and NMHC sea-surface concentrations were highly variable; CO, propene and isoprene levels ranged from 0.6 to 17.5 nmol l−1, 1 to 322 pmol l−1 and 1 to 541 pmol l−1, respectively. The CO and alkene concentrations were enhanced in polar waters off of Greenland, which were more stratified because of ice melting and richer in chromophoric dissolved organic matter (CDOM than typical North Atlantic waters. The spatial distribution of the surface concentrations of CO was consistent with our current understanding of CO-induced UV photo-production in the sea. The vertical distributions of the CO and alkenes followed the trend of light penetration, with the concentrations displaying a relatively regular exponential decrease down to non-measurable values below 50 m. However, no diurnal variations of CO or alkene concentrations were observed in the stratified and irradiated surface layers. This finding suggests that the production and removal processes of CO and alkenes were tightly coupled. We tentatively determined a first-order rate constant for the microbial consumption of CO of 0.5 d−1, which is in agreement with previous studies. On several occasions, we observed the existence of subsurface CO maxima at the level of the deep chlorophyll maximum. This finding represents field evidence for the existence of a non-photochemical CO production pathway, most likely of phytoplanktonic origin. The corresponding production rates normalized to the chlorophyll content were in the range of those estimated from laboratory experiments. In general, the vertical distributions of isoprene followed that of the phytoplankton biomass. Hence, oceanic data

  13. Separation of Industrially-Relevant Gas Mixtures With Metal-Organic Frameworks

    Science.gov (United States)

    Herm, Zoey Rose

    The work herein describes the investigation of metal-organic frameworks for industrial applications, specifically gas phase separations of mixtures. Metal-organic frameworks are crystalline molecular scaffolds built from cationic metal vertices and organic bridging ligands. They are porous on a molecular scale and can separate gas mixtures when one component interacts more strongly with the pore walls than others. The near-infinite combination of metals and ligands allows for optimization of metal-organic framework structures for specific separations. (Abstract shortened by UMI.)

  14. Water-Stable Anionic Metal-Organic Framework for Highly Selective Separation of Methane from Natural Gas and Pyrolysis Gas.

    Science.gov (United States)

    Li, Lan; Wang, Xusheng; Liang, Jun; Huang, Yuanbiao; Li, Hongfang; Lin, Zujin; Cao, Rong

    2016-04-20

    A 3D water-stable anionic metal-organic framework [Zn4(hpdia)2]·[NH2(CH3)2]·3DMF·4H2O (FJI-C4) was constructed based on an elaborate phosphorus-containing ligand 5,5'-(hydroxyphosphoryl)diisophthalic acid (H5hpdia). FJI-C4 with narrow one-dimensional (1D) pore channels exhibits high selectivity of C3H8/CH4 and C2H2/CH4. It is the first time for the MOF which contains phosphorus for selective separation of methane from natural gas and pyrolysis gas.

  15. Flammable Gas Safety Program: actual waste organic analysis FY 1996 progress report; Flammable Gas Safety Program: actual waste organic analysis FY 1996 progress report

    Energy Technology Data Exchange (ETDEWEB)

    Clauss, S.A.; Grant, K.E.; Hoopes, V.; Mong, G.M.; Rau, J.; Steele, R.; Wahl, K.H.

    1996-09-01

    This report describes the status of optimizing analytical methods to account for the organic components in Hanford waste tanks, with emphasis on tanks assigned to the Flammable Gas Watch List. The methods developed are illustrated by their application to samples from Tanks 241-SY-103 and 241-S-102. Capability to account for organic carbon in Tank SY-101 was improved significantly by improving techniques for isolating organic constituents relatively free from radioactive contamination and by improving derivatization methodology. The methodology was extended to samples from Tank SY-103 and results documented in this report. Results from analyzing heated and irradiated SY-103 samples (Gas Generation Task) and evaluating methods for analyzing tank waste directly for chelators and chelator fragments are also discussed.

  16. The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

    Science.gov (United States)

    Liu, Chengtang; Ma, Zhuobiao; Mu, Yujing; Liu, Junfeng; Zhang, Chenglong; Zhang, Yuanyuan; Liu, Pengfei; Zhang, Hongxing

    2017-09-01

    Atmospheric non-methane hydrocarbon compounds (NMHCs) were measured at a sampling site in Beijing city from 15 December 2015 to 14 January 2016 to recognize their pollution levels, variation characteristics, and sources. We quantified 53 NMHCs, and the proportions of alkanes, alkenes, acetylene, and aromatics to the total NMHCs were 49.8-55.8, 21.5-24.7, 13.5-15.9, and 9.3-10.7 %, respectively. The variation trends in the NMHC concentrations were basically identical and exhibited remarkable fluctuation, which was mainly ascribed to the variation in meteorological conditions, especially wind speed. The diurnal variations in NMHCs on clear days exhibited two peaks during the morning and evening rush hours, whereas the rush hours' peaks diminished or even disappeared on the haze days, implying that the relative contribution of the vehicular emissions to atmospheric NMHCs depended on the pollution status. Two evident peaks of the propane / propene ratios appeared in the early morning before sun rise and at noontime on clear days, whereas only one peak occurred in the afternoon during the haze days, which were attributed to the relatively fast reactions of propene with OH, NO3, and O3. Based on the chemical kinetic equations, the daytime OH concentrations were calculated to be in the range of 3. 47 × 105-1. 04 × 106 molecules cm-3 on clear days and 6. 42 × 105-2. 35 × 106 molecules cm-3 on haze days. The nighttime NO3 concentrations were calculated to be in the range of 2. 82 × 109-4. 86 × 109 molecules cm-3 on clear days. The correlation coefficients of typical hydrocarbon pairs (benzene / toluene, o-xylene / m,p-xylene, isopentane / n-pentane, etc.) revealed that vehicular emissions and coal combustion were important sources for atmospheric NMHCs in Beijing during the wintertime. Five major emission sources for atmospheric NMHCs in Beijing during the wintertime were further identified by positive matrix factorization (PMF), including gasoline-related emissions

  17. Non-methane hydrocarbons (NMHCs) and their contribution to ozone formation potential in a petrochemical industrialized city, Northwest China

    Science.gov (United States)

    Jia, Chenhui; Mao, Xiaoxuan; Huang, Tao; Liang, Xiaoxue; Wang, Yanan; Shen, Yanjie; Jiang, Wanyanhan; Wang, Huiqin; Bai, Zhilin; Ma, Minquan; Yu, Zhousuo; Ma, Jianmin; Gao, Hong

    2016-03-01

    Hourly air concentrations of fifty-three non-methane hydrocarbons (NMHCs) were measured at downtown and suburb of Lanzhou, a petrochemical industrialized city, Northwest China in 2013. The measured data were used to investigate the seasonal characteristics of NMHCs air pollution and their contributions to the ozone formation in Lanzhou. Annually averaged NMHCs concentration was 38.29 ppbv in downtown Lanzhou. Among 53 NMHCs, alkanes, alkenes, and aromatics accounted for 57%, 23% and 20% of the total NMHCs air concentration, respectively. The atmospheric levels of toluene and propane with mean values of 4.62 and 4.56 ppbv were higher than other NMHCs, respectively. The ambient levels of NMHCs in downtown Lanzhou were compared with measured NMHCs data collected at a suburban site of Lanzhou, located near a large-scale petrochemical industry. Results show that the levels of alkanes, alkenes, and aromatics in downtown Lanzhou were lower by factors of 3-11 than that in west suburb of the city. O3-isopleth plots show that ozone was formed in VOCs control area in downtown Lanzhou and NOx control area at the west suburban site during the summertime. Propylene-equivalent (Prop-Equiv) concentration and the maximum incremental reactivity (MIR) in downtown Lanzhou indicate that cis-2-butene, propylene, and m/p-xylene were the first three compounds contributing to ozone formation potentials whereas in the petrochemical industrialized west suburb, ethane, propene, and trans-2-Butene played more important role in the summertime ozone formation. Principal component analysis (PCA) and multiple linear regression (MLR) were further applied to identify the dominant emission sources and examine their fractions in total NMHCs. Results suggest that vehicle emission, solvent usage, and industrial activities were major sources of NMHCs in the city, accounting for 58.34%, 22.19%, and 19.47% of the total monitored NMHCs in downtown Lanzhou, respectively. In the west suburb of the city

  18. Direct measurement of adsorbed gas redistribution in metal-organic frameworks.

    Science.gov (United States)

    Chen, Ying-Pin; Liu, Yangyang; Liu, Dahuan; Bosch, Mathieu; Zhou, Hong-Cai

    2015-03-04

    Knowledge about the interactions between gas molecules and adsorption sites is essential to customize metal-organic frameworks (MOFs) as adsorbents. The dynamic interactions occurring during adsorption/desorption working cycles with several states are especially complicated. Even so, the gas dynamics based upon experimental observations and the distribution of guest molecules under various conditions in MOFs have not been extensively studied yet. In this work, a direct time-resolved diffraction structure envelope (TRDSE) method using sequential measurements by in situ synchrotron powder X-ray diffraction has been developed to monitor several gas dynamic processes taking place in MOFs: infusion, desorption, and gas redistribution upon temperature change. The electron density maps indicate that gas molecules prefer to redistribute over heterogeneous types of sites rather than to exclusively occupy the primary binding sites. We found that the gas molecules are entropically driven from open metal sites to larger neighboring spaces during the gas infusion period, matching the localized-to-mobile mechanism. In addition, the partitioning ratio of molecules adsorbed at each site varies with different temperatures, as opposed to an invariant distribution mode. Equally important, the gas adsorption in MOFs is intensely influenced by the gas-gas interactions, which might induce more molecules to be accommodated in an orderly compact arrangement. This sequential TRDSE method is generally applicable to most crystalline adsorbents, yielding information on distribution ratios of adsorbates at each type of site.

  19. Mass Transfer Enhancement of Gas Absorption by Adding the Dispersed Organic Phases

    Institute of Scientific and Technical Information of China (English)

    张志刚; 许天行; 李文秀; 纪智玲; 许光荣

    2011-01-01

    Mass transfer enhancement of gas absorption by adding a dispersed organic phase has been studied in this work. Various dispersed organic phases (heptanol, octanol, isoamyl alcohol, heptane, octane, and isooctane) were tested respectively in the experiment. According to the theoretical model and experimental data, the overall volumetric mass transfer coefficient and enhancement factor were obtained under different dispersed organic phase volume fraction and stirring speed. The experimental results indicate that gas-liquid mass transfer is enhanced at different level by adding a dispersed organic phase. The best performance of enhancement were achieved with the dispersed organic phase volumetric fraction of 5% and under an intermediate stirring speed of 670 r·min^-1. Among the organic phases tested in the experiment, alcohols show better performance, which gave 20% higher enhance-ment of overall volumetric mass transfer coefficient than adding alkanes.

  20. Portable organic gas detection sensor based on the effect of guided-mode resonance

    Science.gov (United States)

    Guo, Liang; Wang, Qi; Huang, Yuanshen; Zhang, Dawei

    2017-01-01

    A novel organic gas detection sensor based on the effect of guided-mode resonance is proposed in this paper. The sensor is designed to operate in the visible light band. It contains four main sections: a light source, a miniature gas chamber composed of a guided-mode resonant filter, a diffraction grating, and a CCD image sensor. When bunched visible light is irradiated vertically to the gas chamber, it passes through the gas chamber and diffraction grating, and is then received by the CCD sensor. The optical signal received by the CCD sensor is then reduced to the spectrum using a specific algorithm. When organic gases are injected into the gas chamber, there is a shift in the wavelength of resonant reflection, and the magnitude of this shift is proportional to the refractive index of the gas. The large variation in the refractive indexes of industrially important organic gases means that their characteristic peak wavelengths can be easily identified. As a result, this system can quickly detect organic gases. To verify the feasibility of this technique, we use finite difference time domain solutions to simulate the results. The sensitivity of this type of sensor can reach wavelength differences of 0.001 nm, which means that the sensor has high potential for application in portable, high-precision detection systems.

  1. The Mars Phoenix Thermal Evolved-Gas Analysis: The Role of an Organic Free Blank in the Search for Organics

    Science.gov (United States)

    Lauer, H. V., Jr.; Ming, Douglas W.; Sutter, B.; Golden, D. C.; Morris, Richard V.; Boynton, W. V.

    2008-01-01

    The Thermal Evolved-Gas Analyzer (TEGA) instrument onboard the 2007 Phoenix Lander will perform differential scanning calorimetry (DSC) and evolved-gas analysis of soil samples collected from the surface. Data from the instrument will be compared with Mars analog mineral standards, collected under TEGA Mars-like conditions to identify the volatile-bearing mineral phases [1] (e.g., Fe-oxyhydroxides, phyllosilicates, carbonates, and sulfates) found in the Martian soil. Concurrently, the instrument will be looking for indications of organics that might also be present in the soil. Organic molecules are necessary building blocks for life, although their presence in the ice or soil does not indicate life itself. The spacecraft will certainly bring organic contaminants to Mars even though numerous steps were taken to minimize contamination during the spacecraft assembly and testing. It will be essential to distinguish possible Mars organics from terrestrial contamination when TEGA instrument begins analyzing icy soils. To address the above, an Organic Free Blank (OFB) was designed, built, tested, and mounted on the Phoenix spacecraft providing a baseline for distinguishing Mars organics from terrestrial organic contamination. Our objective in this report is to describe some of the considerations used in selecting the OFB material and then report on the processing and analysis of the final candidate material

  2. Boron Trifluoride Gas Adsorption in Metal-Organic Frameworks.

    Science.gov (United States)

    Siu, Paul W; Siegfried, John P; Weston, Mitchell H; Fuller, Patrick E; Morris, William; Murdock, Christopher R; Hoover, William J; Richardson, Rachelle K; Rodriguez, Stephanie; Farha, Omar K

    2016-12-05

    Coordinatively unsaturated metal-organic frameworks (MOFs) were studied for boron trifluoride (BF3) sorption. MOF-74-Mg, MOF-74-Mn, and MOF-74-Co show high initial uptake (below 6.7 × 10(-3) bar) with negligible deliverable capacity. The BF3 isotherm of MOF-74-Cu exhibits gradual uptake up to 0.9 bar and has a deliverable gravimetric capacity that is more than 100% higher than activated carbon. Two other Cu(2+) MOFs, MOF-505 and HKUST-1, have slightly lower deliverable capacities compared to MOF-74-Cu.

  3. Collaborative interactions to enhance gas binding energy in porous metal-organic frameworks.

    Science.gov (United States)

    Lin, Rui-Biao; Chen, Banglin

    2017-03-01

    Metal-organic frameworks (MOFs) are potentially useful materials for hydrogen and methane storage. However, the weak interactions between the MOF host and gas guest molecules have limited their storage capacities at elevated temperatures. In this issue, Alkordi et al. [IUCrJ (2017), 4, 131-135] illustrate an example of a porous MOF with a suitable pore size and unique pore surface for enhanced interaction with hydrogen molecules, providing the promise of further increasing the gas binding affinity through collaborative interactions.

  4. [Treatment of organic waste gas by adsorption rotor].

    Science.gov (United States)

    Zhu, Run-Ye; Zheng, Liang-Wei; Mao, Yu-Bo; Wang, Jia-De

    2013-12-01

    The adsorption rotor is applicable to treating organic waste gases with low concentration and high air volume. The performance of adsorption rotor for purifying organic waste gases was investigated in this paper. Toluene was selected as the simulative gaseous pollutant and the adsorption rotor was packed with honeycomb modified 13X molecular sieves (M-13X). Experimental results of the fixed adsorption and the rotor adsorption were analyzed and compared. The results indicated that some information on the fixed adsorption was useful for the rotor adsorption. Integrating the characteristics of the adsorbents, waste gases and the structures of the rotor adsorption, the formulas on optimal rotor speed and cycle removal efficiency of the adsorption rotor were deduced, based on the mass and heat balances of the adsorbing process. The numerical results were in good agreement with the experimental data, which meant that the formulas on optimal rotor speed and cycle removal efficiency could be effectively applied in design and operation of the adsorption rotor.

  5. Organic richness and gas generation potential of Permian Barren Measures from Raniganj field, West Bengal, India

    Indian Academy of Sciences (India)

    Annapurna Boruah; S Ganapathi

    2015-07-01

    The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of Damodar Basin were analysed to evaluate their gas generation potential using Rock–Eval pyrolysis techniques. Petrographic analysis brings out the lithofacies of Barren Measures as carbonaceous silty shale, iron rich claystone and sand-shale intercalation. The total organic content (TOC) of the shale units of Barren Measures ranges from 3.75 to 20.9 wt%, whereas hydrogen index (HI) ranges from 58.45 to 125.34 mg HC/g TOC. Present study suggests early to late maturated (0.6–1%) organic matters in Barren Measures with gas prone type III kerogen. The study analysed the effect of burial history on the preservation and maturation of organic matters. The organic richness, kerogen type, thermal maturity and petrographic properties of Barren Measures signify fair to excellent gas generation potential.

  6. Volatile organic compound emissions from unconventional natural gas production: Source signatures and air quality impacts

    Science.gov (United States)

    Swarthout, Robert F.

    Advances in horizontal drilling and hydraulic fracturing over the past two decades have allowed access to previously unrecoverable reservoirs of natural gas and led to an increase in natural gas production. Intensive unconventional natural gas extraction has led to concerns about impacts on air quality. Unconventional natural gas production has the potential to emit vast quantities of volatile organic compounds (VOCs) into the atmosphere. Many VOCs can be toxic, can produce ground-level ozone or secondary organic aerosols, and can impact climate. This dissertation presents the results of experiments designed to validate VOC measurement techniques, to quantify VOC emission rates from natural gas sources, to identify source signatures specific to natural gas emissions, and to quantify the impacts of these emissions on potential ozone formation and human health. Measurement campaigns were conducted in two natural gas production regions: the Denver-Julesburg Basin in northeast Colorado and the Marcellus Shale region surrounding Pittsburgh, Pennsylvania. An informal measurement intercomparison validated the canister sampling methodology used throughout this dissertation for the measurement of oxygenated VOCs. Mixing ratios of many VOCs measured during both campaigns were similar to or higher than those observed in polluted cities. Fluxes of natural gas-associated VOCs in Colorado ranged from 1.5-3 times industry estimates. Similar emission ratios relative to propane were observed for C2-C6 alkanes in both regions, and an isopentane:n-pentane ratio ≈1 was identified as a unique tracer for natural gas emissions. Source apportionment estimates indicated that natural gas emissions were responsible for the majority of C2-C8 alkanes observed in each region, but accounted for a small proportion of alkenes and aromatic compounds. Natural gas emissions in both regions accounted for approximately 20% of hydroxyl radical reactivity, which could hinder federal ozone standard

  7. Development of gas chromatography analysis of fatty acids in marine organisms.

    Science.gov (United States)

    Tang, Baokun; Row, Kyung Ho

    2013-08-01

    The gas chromatographic analysis of fatty acids has attracted considerable interest. In this analysis, the common derivatives of fatty acids, such as fatty acid methyl esters, can be detected using a flame ionization detector and the mass spectra can indicate the true structure of fatty acids. This paper reviews gas chromatographic methods for obtaining fatty acids from marine organisms. The stationary phase and detector for applications in gas chromatography are discussed. This article also reviews the components of fatty acids in marine animals, marine plants and marine microorganisms.

  8. Metal-Organic Frameworks for Sensing Applications in the Gas Phase

    OpenAIRE

    Sabine Achmann; Gunter Hagen; Jaroslaw Kita; Malkowsky, Itamar M.; Christoph Kiener; Ralf Moos

    2009-01-01

    Several metal-organic framework (MOF) materials were under investigated to test their applicability as sensor materials for impedimetric gas sensors. The materials were tested in a temperature range of 120 °C - 240 °C with varying concentrations of O2, CO2, C3H8, NO, H2, ethanol and methanol in the gas atmosphere and under different test gas humidity conditions. Different sensor configurations were studied in a frequency range of 1 Hz -1 MHz and time-continuous measurements were performed at ...

  9. Partition coefficients of organic compounds in new imidazolium based ionic liquids using inverse gas chromatography.

    Science.gov (United States)

    Revelli, Anne-Laure; Mutelet, Fabrice; Jaubert, Jean-Noël

    2009-06-05

    Partition coefficients of organic compounds in four ionic liquids: 1-ethanol-3-methylimidazolium tetrafluoroborate, 1-ethanol-3-methylimidazolium hexafluorophosphate, 1,3-dimethylimidazolium dimethylphosphate and 1-ethyl-3-methylimidazolium diethylphosphate were measured using inverse gas chromatography from 303.3 to 332.55K. The influence of gas-liquid and gas-solid interfacial adsorption of different solutes on ionic liquids was also studied. Most of the polar solutes were retained largely by partition while light hydrocarbons were retained predominantly by interfacial adsorption on the ionic liquids studied in this work. The solvation characteristics of the ionic liquids were evaluated using the Abraham solvation parameter model.

  10. Evaluation of shale gas potential based on organic matter characteristics and gas concentration in the Devonian Horn River Formation, Canada

    Science.gov (United States)

    Choi, Jiyoung; Hong, Sung Kyung; Lee, Hyun Suk

    2017-04-01

    In this study, we investigate organic matter characteristics from the analysis of Rock-Eval6 and biomarker, and estimate methane concentration from headspace method in the Devonian Horn River Formation, which is one of the largest shale reservoir in western Canada. The Horn River Formation consists of the Evie, Otterpark and Muskwa members in ascending stratigraphic order. Total Organic Carbon (TOC) ranges from 0.34 to 7.57 wt%, with an average of 2.78 wt%. The Evie, middle Otterpark and Muskwa members have an average TOC of more than 3%, whereas those of the lower and upper Otterpark Member are less than 2%. Based on Pristane/n-C17 (0.2 0.6) and Phytane/n-C18 (0.3 0.9) ratios, the organic matter in the Evie, middle Otterpark and Muskwa members mainly consists of type II kerogen which are formed in reducing marine environment. Thermal maturity were examined through the use of the distributions of Phenanthrene (P) and Methylphenantrenes (MP) based on m/z 178 and 192 mass chromatograms, respectively (Radke et al., 1982). The methylphenanthrene index (MPI-1) are calculated as follows : MPI-1 = 1.5 × (2MP+3MP)/(P+1MP+9MP), and Ro are calculated as follows : Ro = -0.6 × MPI-1 + 2.3. Estimated Ro ranges between 1.88 and 1.93%, which indicates the last stage of wet gas generation. The methane concentrations in headspace range from 15 to 914 ppmv, with an average of 73.5 ppmv. The methane concentrations in the Evie, middle Otterpark and Muskwa members (up to 914 ppmv) are higher than those of the lower and upper Otterpark Member (up to 75 ppmv). Considering the organic geochemical characteristics and gas concentrations, the shale gas potentials of the Evie, middle Otterpark and Muskwa members are higher than those of other members.

  11. Study on the threshold value of organic enrichment of carbonate as gas source rocks

    Institute of Scientific and Technical Information of China (English)

    XUE Haitao; LU Shuangfang; ZHONG Ningning; WANG Bo

    2004-01-01

    In this paper, calculations have been performed about gas quantity of generation, adsorption, dissolving in oil, dissolving in water, diffusion of unit area carbonate rocks at different geologic conditions in the Tarim basin. According to the material balance principle, the corresponding organic carbon content when gas started expelling from source rocks with separate phases has been worked out. We regard it as the theoretical threshold value (TOCmin) of gas source rocks under the same geologic condition. Based on the simulating calculation, a fact has been discovered that TOCmin decreases with the increasing source rocks thickness, decreases at the beginning and then increases with the increasing maturity and decreases with the better type of organic matter. TOCmin evaluation table of carbonate gas source rocks in the Tarim basin has been established. Investigations indicate that the TOCmin of carbonate gas source rocks varies greatly with the differences of geologic conditions, and gas source rocks cannot be evaluated with a unified TOC threshold value. And we also establish a preliminary evaluation table of TOC industrial threshold value, TOCgy, of carbonate gas source rocks in the Tarim basin.

  12. Impact of Chlorine Dioxide Gas Sterilization on Nosocomial Organism Viability in a Hospital Room

    Directory of Open Access Journals (Sweden)

    Angela L. Hewlett

    2013-06-01

    Full Text Available To evaluate the ability of ClO2 to decontaminate pathogens known to cause healthcare-associated infections in a hospital room strains of Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis, Mycobacterium smegmatis, and Staphylococcus aureus were spot placed in duplicate pairs at 10 sites throughout a hospital room and then exposed to ClO2 gas. Organisms were collected and evaluated for reduction in colony forming units following gas exposure. Six sterilization cycles with varied gas concentrations, exposure limits, and relative humidity levels were conducted. Reductions in viable organisms achieved ranged from 7 to 10-log reductions. Two sterilization cycles failed to produce complete inactivation of organisms placed in a bathroom with the door closed. Reductions of organisms in the bathroom ranged from 6-log to 10-log reductions. Gas leakage between hospital floors did not occur; however, some minor gas leakage from the door of hospital room was measured which was subsequently sealed to prevent further leakage. Novel technologies for disinfection of hospital rooms require validation and safety testing in clinical environments. Gaseous ClO2 is effective for sterilizing environmental contamination in a hospital room. Concentrations of ClO2 up to 385 ppm were safely maintained in a hospital room with enhanced environmental controls.

  13. Impact of Chlorine Dioxide Gas Sterilization on Nosocomial Organism Viability in a Hospital Room

    Science.gov (United States)

    Lowe, John J.; Gibbs, Shawn G.; Iwen, Peter C.; Smith, Philip W.; Hewlett, Angela L.

    2013-01-01

    To evaluate the ability of ClO2 to decontaminate pathogens known to cause healthcare-associated infections in a hospital room strains of Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis, Mycobacterium smegmatis, and Staphylococcus aureus were spot placed in duplicate pairs at 10 sites throughout a hospital room and then exposed to ClO2 gas. Organisms were collected and evaluated for reduction in colony forming units following gas exposure. Six sterilization cycles with varied gas concentrations, exposure limits, and relative humidity levels were conducted. Reductions in viable organisms achieved ranged from 7 to 10-log reductions. Two sterilization cycles failed to produce complete inactivation of organisms placed in a bathroom with the door closed. Reductions of organisms in the bathroom ranged from 6-log to 10-log reductions. Gas leakage between hospital floors did not occur; however, some minor gas leakage from the door of hospital room was measured which was subsequently sealed to prevent further leakage. Novel technologies for disinfection of hospital rooms require validation and safety testing in clinical environments. Gaseous ClO2 is effective for sterilizing environmental contamination in a hospital room. Concentrations of ClO2 up to 385 ppm were safely maintained in a hospital room with enhanced environmental controls. PMID:23792697

  14. Assessment and control of chemical risk from organic vapors for attendants in a gas station

    Directory of Open Access Journals (Sweden)

    Stephanie Ehmig Santillán

    2015-12-01

    Full Text Available This research comprises monitoring, assessment and recommendations for chemical risk originating from organic vapors (benzene, toluene and xylene of fuel (super and extra gasoline to which attendants at a gas station are exposed. Given the concentration measured of organic vapors (benzene, toluene and xylene the chemical risk to which attendants are exposed in the supply area is acceptable. Control measures are recommended to ensure healthy working conditions for gas station attendants and also to avoid occurrence of occupational diseases in the medium or long term

  15. Evaluating greenhouse gas impacts of organic waste management options using life cycle assessment.

    Science.gov (United States)

    Kong, Dung; Shan, Jilei; Iacoboni, Mario; Maguin, Stephen R

    2012-08-01

    Efforts to divert organics away from landfills are viewed by many as an important measure to significantly reduce the climate change impacts of municipal solid waste management. However, the actual greenhouse gas (GHG) impacts of organics diversion from landfills have yet to be thoroughly evaluated and whether such a diversion provides significant environmental benefits in terms of GHG impacts must be answered. This study, using California-specific information, aimed to analyse the GHG impacts of organics diversion through a life-cycle assessment (LCA). This LCA considered all aspects of organics management including transportation, materials handling, GHG emissions, landfill gas capture/utilization, energy impacts, and carbon sequestration. The LCA study evaluated overall GHG impacts of landfilling, and alternative management options such as composting and anaerobic digestion for diverted organic waste. The LCA analysis resulted in net GHG reductions of 0.093, 0.048, 0.065 and 0.073 tonnes carbon equivalent per tonne organic waste for landfilling, windrow composting, aerated static pile composting, and anaerobic digestion, respectively. This study confirms that all three options for organics management result in net reductions of GHG emissions, but it also shows that organics landfilling, when well-managed, generates greater GHG reductions. The LCA provides scientific insight with regards to the environmental impacts of organics management options, which should be considered in decision and policy-making. The study also highlights the importance of how site and case-specific conditions influence project outcomes when considering organic waste management options.

  16. Gas separation using novel materials: kinetics of gas adsorption on RPM-1 and Cu-BTC metal-organic frameworks

    Science.gov (United States)

    Lask, Kathleen; Krungleviciute, Vaiva; Migone, Aldo; Lee, J.-Y.; Li, Jing

    2007-03-01

    We have measured the adsorption kinetics of two gases, freon and argon, on two microporous metal-organic framework materials, RPM-1 (or [Co3(bpdc)3bpy].4DMF.H2O, bpdc = biphenyldicarboxylate) and Cu-BTC (or [Cu3(btc)2(H2O)3], btc = benzenetricarboxylate). The measurements were conducted at comparable values of the scaled temperatures (Tisotherm/Tcritical) for the respective gases. In our experiments, we monitor the pressure decrease as a function of time after a dose of gas is admitted into the experimental cell. The kinetics results obtained for both gases are similar on Cu-BTC, while they are significantly different in RPM-1. Our results indicate that RPM-1 has potential for gas separation for mixtures of species with dimensions similar to argon and freon; this is not the case for Cu-BTC MOF.

  17. Emissions and performance evaluation of a dedicated compressed natural gas saturn

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, J.W.; Taylor, J.D. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-07-01

    The use of compressed natural gas (CNG) as a transportation fuel has been identified as one strategy that can help ameliorate some problems, which include a growing dependence on imported oil (and all its ramifications) and the persistent contributions that mobile sources make to urban air pollution, associated with the use of conventional petroleum fuels. The attributes and limitations of CNG as a fuel for spark-ignition engines have been presented by others. The attributes are associated with its high octane rating, low cost relative to other alternative fuels, its availability, the absence of running and diurnal evaporative emissions, and its demonstrated potential for producing extremely low exhaust emissions-particularly if the volatile organic compounds (VOCs) emitted are expressed in terms of reactivity adjusted non-methane organic gases (RANMOG). The limitations associated with the use of CNG include its limited refueling infrastructure, the cost of refueling facilities, the cost of on-board fuel storage tanks, and its relatively low energy density. Because one impediment to CNG use is the cost associated with producing a CNG-powered vehicle, a study was initiated at the University of Tennessee under sponsorship by the Saturn Corporation to determine how a CNG vehicle (specifically, a 1991 Saturn SL1) could be engineered so it could be produced with a minimal impact on the production of the base vehicle. The present study was undertaken to further investigate the emissions reduction potential of the Saturn CNG vehicle. In the previous study the role of exhaust gas recirculation was not thoroughly investigated. Those involved in the study agreed that the NO{sub x} levels could be brought down well below California ULEV levels without increasing either the non-methane organic gases or the CO levels.

  18. Photoluminescent Metal–Organic Frameworks for Gas Sensing

    Science.gov (United States)

    Lin, Rui‐Biao; Liu, Si‐Yang; Ye, Jia‐Wen; Li, Xu‐Yu

    2016-01-01

    Luminescence of porous coordination polymers (PCPs) or metal–organic frameworks (MOFs) is sensitive to the type and concentration of chemical species in the surrounding environment, because these materials combine the advantages of the highly regular porous structures and various luminescence mechanisms, as well as diversified host‐guest interactions. In the past few years, luminescent MOFs have attracted more and more attention for chemical sensing of gas‐phase analytes, including common gases and vapors of solids/liquids. While liquid‐phase and gas‐phase luminescence sensing by MOFs share similar mechanisms such as host‐guest electron and/or energy transfer, exiplex formation, and guest‐perturbing of excited‐state energy level and radiation pathways, via various types of host‐guest interactions, gas‐phase sensing has its unique advantages and challenges, such as easy utilization of encapsulated guest luminophores and difficulty for accurate measurement of the intensity change. This review summarizes recent progresses by using luminescent MOFs as reusable sensing materials for detection of gases and vapors of solids/liquids especially for O2, highlighting various strategies for improving the sensitivity, selectivity, stability, and accuracy, reducing the materials cost, and developing related devices.

  19. Organic Inclusions as an Indicator of Oil/Gas Potential Assessment of Carbonate Reservoir Beds

    Institute of Scientific and Technical Information of China (English)

    施继锡; 兰文波

    1993-01-01

    Organic inclusions could be formed at the stages of either primary or secondary migration of hydrocarbons so long as mineral crystallization or recrystallization takes place in the sediments, presenting a direct indicator of oil/gas evolution, migration and abundance.Based on the strdy of organic inclusions in carbonate-type reser voir beds of commercial importance from North China ,Xingjing ,North Jiangsu, Sichuan and Guizhou in China ,many inclusion parameters for oil/gas potential assessment of carbonate reservoir beds are summarized in this paper, including;1) Types of organic inclusion; Ccmmercially important oil beds are characterized by inclusions consisting of either pure liquid hydrocarbons or liquid plus minor gaseous hydrocarbons, while commercially important gas reservoirs are characterized by inclusions consisting of either pure gaseous hydrocarbons or gas plus minor liquid hydrocarbons.2)Quantity of organic inclusions:The num-ber of organic inclusions in commercially important oil/gas reservoirs is over 60% of the total inclusion percent-tage.3)Temperature of saline inclusions .The homogenization temperatures of contemporaneous saline inclu-sions in oil reservoirs range from 91-161℃, while in gas reservoirs from 150-250℃).4) Inclusion composition: In commercially important oil reservoirs, C1/C2=2-10,C1/C3=2-4,C1/C4=2-21,(C2-C4)/(C1-C4)(%)>20,(CH4+CO+H2)/CO2(molecules/g)=0.5-1.0,and in C2-C3-nC4 triangle diagram there should be an upside-down triangle with the apex within the ellipse, while in commercial gas reservoirs, C1/C2=10-35,C1/C3=14-82,C1/C4=21-200,(C2-C4)/(C1-C4)(%)1,and there would be an upright triangle with the apex within the ellipse.The abovementioned parameters have been used to evaluate a number of other unknown wells or regions and the results are very satisfactory.It is valid to use organic inclusions as an indicator to assess the oil/gas potential during oil/gas exploration and prospecting,This approach is effective

  20. Organic Iodine Adsorption by AgZ under Prototypical Vessel Off-Gas Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jubin, Robert Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jordan, J. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-30

    U.S. regulations will require the removal of 129I from the off-gas streams of any used nuclear fuel (UNF) reprocessing plant prior to discharge of the off-gas to the environment. Multiple off-gas streams within a UNF reprocessing plant combine prior to release, and each of these streams contains some amount of iodine. For an aqueous UNF reprocessing plant, these streams include the dissolver off-gas, the cell off-gas, the vessel off-gas (VOG), the waste off-gas and the shear off-gas. To achieve regulatory compliance, treatment of multiple off-gas streams within the plant must be performed. Preliminary studies have been completed on the adsorption of I2 onto silver mordenite (AgZ) from prototypical VOG streams. The study reported that AgZ did adsorb I2 from a prototypical VOG stream, but process upsets resulted in an uneven feed stream concentration. The experiments described in this document both improve the characterization of I2 adsorption by AgZ from dilute gas streams and further extend it to include characterization of the adsorption of organic iodides (in the form of CH3I) onto AgZ under prototypical VOG conditions. The design of this extended duration testing was such that information about the rate of adsorption, the penetration of the iodine species, and the effect of sorbent aging on iodine removal in VOG conditions could be inferred.

  1. Molecular dynamics simulations of gas diffusion in metal-organic frameworks: argon in CuBTC.

    Science.gov (United States)

    Skoulidas, Anastasios I

    2004-02-11

    The class of coordination polymers known as metal-organic frameworks (MOFs) has three-dimensional porous structures that are considered as a promising alternative to zeolites and other nanoporous materials for catalysis, gas adsorption, and gas separation applications. In this paper, we present the first study of gas diffusion inside an MOF and compare the observed diffusion to known behaviors in zeolites. Using grand canonical Monte Carlo and equilibrium molecular dynamics, we calculate the adsorption isotherm and self-, corrected, and transport diffusivities for argon in the CuBTC metal-organic framework. Our results indicate that diffusion of Ar in CuBTC is very similar to Ar diffusion in silica zeolites in magnitude, concentration, and temperature dependence. This conclusion appears to apply to a broad range of MOF structures.

  2. Incorporation of Gas Chromatography-Mass Spectrometry into the Undergraduate Organic Chemistry Laboratory Curriculum

    Science.gov (United States)

    Giarikos, Dimitrios G.; Patel, Sagir; Lister, Andrew; Razeghifard, Reza

    2013-01-01

    Gas chromatography-mass spectrometry (GC-MS) is a powerful analytical tool for detection, identification, and quantification of many volatile organic compounds. However, many colleges and universities have not fully incorporated this technique into undergraduate teaching laboratories despite its wide application and ease of use in organic…

  3. Identification and measurement of chlorinated organic pesticides in water by electron-capture gas chromatography

    Science.gov (United States)

    Lamar, William L.; Goerlitz, Donald F.; Law, LeRoy M.

    1965-01-01

    Pesticides, in minute quantities, may affect the regimen of streams, and because they may concentrate in sediments, aquatic organisms, and edible aquatic foods, their detection and their measurement in the parts-per-trillion range are considered essential. In 1964 the U.S. Geological Survey at Menlo Park, Calif., began research on methods for monitoring pesticides in water. Two systems were selected--electron-capture gas chromatography and microcoulometric-titration gas chromatography. Studies on these systems are now in progress. This report provides current information on the development and application of an electron-capture gas chromatographic procedure. This method is a convenient and extremely sensitive procedure for the detection and measurement of organic pesticides having high electron affinities, notably the chlorinated organic pesticides. The electron-affinity detector is extremely sensitive to these substances but it is not as sensitive to many other compounds. By this method, the chlorinated organic pesticide may be determined on a sample of convenient size in concentrations as low as the parts-per-trillion range. To insure greater accuracy in the identifications, the pesticides reported were separated and identified by their retention times on two different types of gas chromatographic columns.

  4. Incorporation of Gas Chromatography-Mass Spectrometry into the Undergraduate Organic Chemistry Laboratory Curriculum

    Science.gov (United States)

    Giarikos, Dimitrios G.; Patel, Sagir; Lister, Andrew; Razeghifard, Reza

    2013-01-01

    Gas chromatography-mass spectrometry (GC-MS) is a powerful analytical tool for detection, identification, and quantification of many volatile organic compounds. However, many colleges and universities have not fully incorporated this technique into undergraduate teaching laboratories despite its wide application and ease of use in organic…

  5. Massive preparation of pitch-based organic microporous polymers for gas storage.

    Science.gov (United States)

    Li, Wenqing; Zhang, Aijuan; Gao, Hui; Chen, Mingjie; Liu, Anhua; Bai, Hua; Li, Lei

    2016-02-14

    A general challenge for preparing organic microporous polymers (MOPs) is to use cheap and sustainable building blocks while retaining the advanced functions. We demonstrate a strategy to massively prepare pitch-based MOPs, which are thermally and chemically stable. A maximum BET surface area of 758 m(2) g(-1) and high gas storage capacity were achieved.

  6. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    NARCIS (Netherlands)

    Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

    2008-01-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

  7. SEDIMENTARY ORGANIC MATTER' S CLASSIFICATION OF OIL-GAS SOURCE ROCKS IN CHINA

    Institute of Scientific and Technical Information of China (English)

    JinKuili; LiuDameng; XiaoXianming

    1996-01-01

    According to the study on the oil-gas source rocks in China for ten years,in connection with the microscopic, submicroscopic levels, the authors used the microscope photometry together with transmission electronic microscopy, scanning electronic microscopy and proposed a new classification for Sedimentary organic matters.

  8. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    NARCIS (Netherlands)

    Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

    2008-01-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

  9. Arctic Vegetation under Climate Change – Biogenic Volatile Organic Compound Emissions and Leaf Anatomy

    DEFF Research Database (Denmark)

    Schollert, Michelle

    Biogenic volatile organic compounds (BVOCs) emitted from terrestrial vegetation are highly reactive non-methane hydrocarbons which participate in oxidative reactions in the atmosphere prolonging the lifetime of methane and contribute to the formation of secondary organic aerosols. The BVOC...... measurements in this thesis were performed using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analyzed by gas chromatography-mass spectrometry following thermal desorption. Also modifications in leaf anatomy in response to the studied effects of climate change were assessed...... by the use of light microscopy and scanning electron microscopy. This thesis reports the first estimates of high arctic BVOC emissions, which suggest that arctic environments can be a considerable source of BVOCs to the atmosphere. The BVOC emissions differed qualitatively and quantitatively for the studied...

  10. Analysis of the Molecules Structure and Vertical Electron Affinity of Organic Gas Impact on Electric Strength

    Science.gov (United States)

    Jiao, Juntao; Xiao, Dengming; Zhao, Xiaoling; Deng, Yunkun

    2016-05-01

    It is necessary to find an efficient selection method to pre-analyze the gas electric strength from the perspective of molecule structure and the properties for finding the alternative gases to sulphur hexafluoride (SF6). As the properties of gas are determined by the gas molecule structure, the research on the relationship between the gas molecule structure and the electric strength can contribute to the gas pre-screening and new gas development. In this paper, we calculated the vertical electron affinity, molecule orbits distribution and orbits energy of gas molecules by the means of density functional theory (DFT) for the typical structures of organic gases and compared their electric strengths. By this method, we find part of the key properties of the molecule which are related to the electric strength, including the vertical electron affinity, the lowest unoccupied molecule orbit (LUMO) energy, molecule orbits distribution and negative-ion system energy. We also listed some molecule groups such as unsaturated carbons double bonds (C=C) and carbonitrile bonds (C≡N) which have high electric strength theoretically by this method. supported by National Natural Science Foundation of China (Nos. 51177101 and 51337006)

  11. Analysis of the Molecules Structure and Vertical Electron Affinity of Organic Gas Impact on Electric Strength

    Institute of Scientific and Technical Information of China (English)

    JIAO Juntao; XIAO Dengming; ZHAO Xiaoling; DENG Yunkun

    2016-01-01

    It is necessary to find an efficient selection method to pre-analyze the gas electric strength from the perspective of molecule structure and the properties for finding the alternative gases to sulphur hexafluoride (SF6).As the properties of gas are determined by the gas molecule structure,the research on the relationship between the gas molecule structure and the electric strength can contribute to the gas pre-screening and new gas development.In this paper,we calculated the vertical electron affinity,molecule orbits distribution and orbits energy of gas molecules by the means of density functional theory (DFT) for the typical structures of organic gases and compared their electric strengths.By this method,we find part of the key properties of the molecule which are related to the electric strength,including the vertical electron affinity,the lowest unoccupied molecule orbit (LUMO) energy,molecule orbits distribution and negativeion system energy.We also listed some molecule groups such as unsaturated carbons double bonds (C=C) and carbonitrile bonds (C≡N) which have high electric strength theoretically by this method.

  12. Formation of complex organic molecules in cold objects: the role of gas-phase reactions

    Science.gov (United States)

    Balucani, Nadia; Ceccarelli, Cecilia; Taquet, Vianney

    2015-04-01

    While astrochemical models are successful in reproducing many of the observed interstellar species, they have been struggling to explain the observed abundances of complex organic molecules. Current models tend to privilege grain surface over gas-phase chemistry in their formation. One key assumption of those models is that radicals trapped in the grain mantles gain mobility and react on lukewarm ( ≳ 30 K) dust grains. Thus, the recent detections of methyl formate (MF) and dimethyl ether (DME) in cold objects represent a challenge and may clarify the respective role of grain-surface and gas-phase chemistry. We propose here a new model to form DME and MF with gas-phase reactions in cold environments, where DME is the precursor of MF via an efficient reaction overlooked by previous models. Furthermore, methoxy, a precursor of DME, is also synthesized in the gas phase from methanol, which is desorbed by a non-thermal process from the ices. Our new model reproduces fairly well the observations towards L1544. It also explains, in a natural way, the observed correlation between DME and MF. We conclude that gas-phase reactions are major actors in the formation of MF, DME and methoxy in cold gas. This challenges the exclusive role of grain-surface chemistry and favours a combined grain-gas chemistry.

  13. Organic molecules in ices and their release into the gas phase

    Science.gov (United States)

    Fayolle, Edith; Oberg, Karin I.; Garrod, Robin; van Dishoeck, Ewine; Rajappan, Mahesh; Bertin, Mathieu; Romanzin, Claire; Michaut, Xavier; Fillion, Jean-Hugues

    2015-08-01

    Organic molecules in the early stages of star formation are mainly produced in icy mantles surrounding interstellar dust grains. Identifying these complex organics and quantifying their abundance during the evolution of young stellar objects is of importance to understand the emergence of life. Simple molecules in ices, up to methanol in size, have been identified in the interstellar medium through their mid-IR vibrations, but band confusion prevents detections of more complex and less abundant organic molecules in interstellar ices. The presence of complex organics on grains can instead be indirectly inferred from observations of their rotational lines in the gas phase following ice sublimation.Thermal sublimation of protostellar ices occurs when icy grains flow toward a central protostar, resulting in the formation of a hot-core or a hot-corinos. The high degree of chemical complexity observed in these dense and warm regions can be the results of i) direct synthesis on the grains followed by desorption, but also to ii) the desorption of precursors from the ice followed by gas-phase chemistry. I will show how spatially resolved millimetric observations of hot cores and cooler protostellar environments, coupled to ice observations can help us pinpoint the ice or gas-phase origin of these organic species.Organic molecules have also recently been observed in cold environments where thermal desorption can be neglected. The presence of these cold molecules in the gas phase is most likely due to non-thermal desorption processes induced by, for e.g., photon-, electron-, cosmic-ray-irradiation, shock, exothermic reactions... I will present laboratory and observational efforts that push our current understanding of these non-thermal desorption processes and how they could be use to quantify the amount of organics in ices.

  14. China organic-rich shale geologic features and special shale gas production issues

    Directory of Open Access Journals (Sweden)

    Yiwen Ju

    2014-06-01

    Full Text Available The depositional environment of organic-rich shale and the related tectonic evolution in China are rather different from those in North America. In China, organic-rich shale is not only deposited in marine environment, but also in non-marine environment: marine-continental transitional environment and lacustrine environment. Through analyzing large amount of outcrops and well cores, the geologic features of organic-rich shale, including mineral composition, organic matter richness and type, and lithology stratigraphy, were analyzed, indicating very special characteristics. Meanwhile, the more complex and active tectonic movements in China lead to strong deformation and erosion of organic-rich shale, well-development of fractures and faults, and higher thermal maturity and serious heterogeneity. Co-existence of shale gas, tight sand gas, and coal bed methane (CBM proposes a new topic: whether it is possible to co-produce these gases to reduce cost. Based on the geologic features, the primary production issues of shale gas in China were discussed with suggestions.

  15. Effect of organic matter properties, clay mineral type and thermal maturity on gas adsorption in organic-rich shale systems

    Science.gov (United States)

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Lewan, Mike; Sun, Xun; Baez, Luis; Beeney, Ken; Sonnenberg, Steve

    2013-01-01

    A series of CH4 adsorption experiments on natural organic-rich shales, isolated kerogen, clay-rich rocks, and artificially matured Woodford Shale samples were conducted under dry conditions. Our results indicate that physisorption is a dominant process for CH4 sorption, both on organic-rich shales and clay minerals. The Brunauer–Emmett–Teller (BET) surface area of the investigated samples is linearly correlated with the CH4 sorption capacity in both organic-rich shales and clay-rich rocks. The presence of organic matter is a primary control on gas adsorption in shale-gas systems, and the gas-sorption capacity is determined by total organic carbon (TOC) content, organic-matter type, and thermal maturity. A large number of nanopores, in the 2–50 nm size range, were created during organic-matter thermal decomposition, and they significantly contributed to the surface area. Consequently, methane-sorption capacity increases with increasing thermal maturity due to the presence of nanopores produced during organic-matter decomposition. Furthermore, CH4 sorption on clay minerals is mainly controlled by the type of clay mineral present. In terms of relative CH4 sorption capacity: montmorillonite ≫ illite – smectite mixed layer > kaolinite > chlorite > illite. The effect of rock properties (organic matter content, type, maturity, and clay minerals) on CH4 adsorption can be quantified with the heat of adsorption and the standard entropy, which are determined from adsorption isotherms at different temperatures. For clay-mineral rich rocks, the heat of adsorption (q) ranges from 9.4 to 16.6 kJ/mol. These values are considerably smaller than those for CH4 adsorption on kerogen (21.9–28 kJ/mol) and organic-rich shales (15.1–18.4 kJ/mol). The standard entropy (Δs°) ranges from -64.8 to -79.5 J/mol/K for clay minerals, -68.1 to -111.3 J/mol/K for kerogen, and -76.0 to -84.6 J/mol/K for organic-rich shales. The affinity of CH4 molecules for sorption on organic matter

  16. Formation of Polymeric Hollow Microcapsules and Microlenses Using Gas-in-Organic-in-Water Droplets

    Directory of Open Access Journals (Sweden)

    Dong Hyun Yoon

    2015-05-01

    Full Text Available This paper presents methods for the formation of hollow microcapsules and microlenses using multiphase microdroplets. Microdroplets, which consist of a gas core and an organic phase shell, were generated at a single junction on a silicon device without surface treatment of the fluidic channels. Droplet, core and shell dimensions were controlled by varying the flow rates of each phase. When the organic solvent was released from the organic phase shell, the environmental conditions changed the shape of the solidified polymer shell to either a hollow capsule or a microlens. A uniform solvent release process produced polymeric capsules with nanoliter gas core volumes and a membrane thickness of approximately 3 μm. Alternatively physical rearrangement of the core and shell allowed for the formation of polymeric microlenses. On-demand formation of the polymer lenses in wells and through-holes polydimethylsiloxane (PDMS structures was achieved. Optical properties of the lenses were controlled by changing the dimension of these structures.

  17. Synthesis of refractory organic matter in the ionized gas phase of the solar nebula.

    Science.gov (United States)

    Kuga, Maïa; Marty, Bernard; Marrocchi, Yves; Tissandier, Laurent

    2015-06-01

    In the nascent solar system, primitive organic matter was a major contributor of volatile elements to planetary bodies, and could have played a key role in the development of the biosphere. However, the origin of primitive organics is poorly understood. Most scenarios advocate cold synthesis in the interstellar medium or in the outer solar system. Here, we report the synthesis of solid organics under ionizing conditions in a plasma setup from gas mixtures (H2(O)-CO-N2-noble gases) reminiscent of the protosolar nebula composition. Ionization of the gas phase was achieved at temperatures up to 1,000 K. Synthesized solid compounds share chemical and structural features with chondritic organics, and noble gases trapped during the experiments reproduce the elemental and isotopic fractionations observed in primitive organics. These results strongly suggest that both the formation of chondritic refractory organics and the trapping of noble gases took place simultaneously in the ionized areas of the protoplanetary disk, via photon- and/or electron-driven reactions and processing. Thus, synthesis of primitive organics might not have required a cold environment and could have occurred anywhere the disk is ionized, including in its warm regions. This scenario also supports N2 photodissociation as the cause of the large nitrogen isotopic range in the solar system.

  18. Organic substances in produced and formation water from unconventional natural gas extraction in coal and shale

    Science.gov (United States)

    Orem, William H.; Tatu, Calin A.; Varonka, Matthew S.; Lerch, Harry E.; Bates, Anne L.; Engle, Mark A.; Crosby, Lynn M.; McIntosh, Jennifer

    2014-01-01

    Organic substances in produced and formation water from coalbed methane (CBM) and gas shale plays from across the USA were examined in this study. Disposal of produced waters from gas extraction in coal and shale is an important environmental issue because of the large volumes of water involved and the variable quality of this water. Organic substances in produced water may be environmentally relevant as pollutants, but have been little studied. Results from five CBM plays and two gas shale plays (including the Marcellus Shale) show a myriad of organic chemicals present in the produced and formation water. Organic compound classes present in produced and formation water in CBM plays include: polycyclic aromatic hydrocarbons (PAHs), heterocyclic compounds, alkyl phenols, aromatic amines, alkyl aromatics (alkyl benzenes, alkyl biphenyls), long-chain fatty acids, and aliphatic hydrocarbons. Concentrations of individual compounds range from organic carbon (TOC) in CBM produced water is generally in the 1–4 mg/L range. Excursions from this general pattern in produced waters from individual wells arise from contaminants introduced by production activities (oils, grease, adhesives, etc.). Organic substances in produced and formation water from gas shale unimpacted by production chemicals have a similar range of compound classes as CBM produced water, and TOC levels of about 8 mg/L. However, produced water from the Marcellus Shale using hydraulic fracturing has TOC levels as high as 5500 mg/L and a range of added organic chemicals including, solvents, biocides, scale inhibitors, and other organic chemicals at levels of 1000 s of μg/L for individual compounds. Levels of these hydraulic fracturing chemicals and TOC decrease rapidly over the first 20 days of water recovery and some level of residual organic contaminants remain up to 250 days after hydraulic fracturing. Although the environmental impacts of the organics in produced water are not well defined, results

  19. Measurement of Organic Acids Produced By The Gas-Phase Ozonolysis of Simple Olefins Using Chemical Ionization Mass Spectrometry (CIMS) as a Function of Temperature And Humidity

    Science.gov (United States)

    Percival, C. J.; Bacak, A.; Leather, K. E.; McGillen, M. R.

    2009-12-01

    Non-methane hydrocarbons (NMHCs) form an important trace component of the atmosphere and are of particular environmental interest because of their deleterious effects on air quality, their numerous (and potentially counteractive) effects on Earth’s climate system and their sophisticated semiochemical roles in the world’s ecosystems. NMHCs are also important precursors to the formation of secondary organic aerosol (SOA) (e.g. Pandis et al., 1991; Kavouras et al., 1999). The ozonolysis reactions of olefins result in complex menageries of products, of which the acids are ubiquitous. Although the gas phase acid concentrations are small, they are thought to be key species in SOA formation as a result of their low volatility (e.g., Ma et al., 2009). Despite this, the factors that control acid formation are not well understood, especially with regards to humidity and temperature. Acid yields will be measured using the newly commissioned EXTreme RAnge (EXTRA) chamber (Leather et al., 2009). EXTRA is a 125 L stainless steel chamber, which can be temperature controlled using a commercial chest freezer unit (for T ≤ -20 °C) or a purpose built oven for T > 25 °C. The EXTRA chamber can be operated at pressures from 10-3800 Torr and at temperatures from 180-473 K. The stainless steel chamber walls have been coated with PFA to minimize wall loss of radicals. Fans, located at both ends of the cylinder, promote rapid mixing of reactants. Six sample ports are located at either end of the chamber for connection to ADS-GC-ECD, CIMS and commercial sensors such as a Thermo Electron Corporation 49i Ozone Analyzer, an Edinburgh Instruments Gascard CO2 sensor and a Trace Analytical inc. RGA3 CO analyzer. Experiments will be performed as a function of atmospherically relevant temperatures (T= 180-300 K). The field CIMS has sub ppt(v) L.O.D.s with a sub 1 Hz time response so will enable products to be quantified at very low concentrations in real time. Acid products will be detected

  20. Biogas in organic agriculture-effects on productivity, energy self-sufficiency and greenhouse gas emissions

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Olesen, Jørgen E; Jørgensen, Uffe

    2014-01-01

    Anaerobic digestion of manure and crops provides the possibility of a combined production of renewable energy and organic fertilizer on organic farms and has been suggested as an option to improve sustainability of organic agriculture. In the present study, the consequences of implementation...... of anaerobic digestion and biogas production were analyzed on a 1000 ha model farm with combined dairy and cash crop production, representing organic agriculture in Denmark. The effects on crop rotation, nitrogen flows and losses, yield, energy balance and greenhouse gas (GHG) emissions were evaluated for four......, reduced number of livestock and import of biomass from cuttings made in ungrazed meadows. These four scenarios were compared with the current situation in organic agriculture in Denmark and to a situation where slurry from conventional agriculture is no longer imported. Implementation of anaerobic...

  1. Organic petrology and coalbed gas content, Wilcox Group (Paleocene-Eocene), northern Louisiana

    Science.gov (United States)

    Hackley, P.C.; Warwick, P.D.; Breland, F.C.

    2007-01-01

    Wilcox Group (Paleocene-Eocene) coal and carbonaceous shale samples collected from four coalbed methane test wells in northern Louisiana were characterized through an integrated analytical program. Organic petrographic analyses, gas desorption and adsorption isotherm measurements, and proximate-ultimate analyses were conducted to provide insight into conditions of peat deposition and the relationships between coal composition, rank, and coalbed gas storage characteristics. The results of petrographic analyses indicate that woody precursor materials were more abundant in stratigraphically higher coal zones in one of the CBM wells, consistent with progradation of a deltaic depositional system (Holly Springs delta complex) into the Gulf of Mexico during the Paleocene-Eocene. Comparison of petrographic analyses with gas desorption measurements suggests that there is not a direct relationship between coal type (sensu maceral composition) and coalbed gas storage. Moisture, as a function of coal rank (lignite-subbituminous A), exhibits an inverse relationship with measured gas content. This result may be due to higher moisture content competing for adsorption space with coalbed gas in shallower, lower rank samples. Shallower ( 600??m) coal samples containing less moisture range from under- to oversaturated with respect to their CH4 adsorption capacity.

  2. Volatile organic compound gas sensor based on aluminum-doped zinc oxide with nanoparticle.

    Science.gov (United States)

    Choi, Nak-Jin; Lee, Hyung-Kun; Moon, Seung Eon; Yang, Woo Seok; Kim, Jongdae

    2013-08-01

    Thick film semiconductor gas sensors based on aluminum-doped zinc oxide (AZO) with nanoparticle size were fabricated to detect volatile organic compound (VOC) existed in building, especially, formaldehyde (HCHO) gas which was known as the cause of sick building syndrome. The sensing materials for screen printing were prepared using roll milling process with binder. The crystallite sizes of prepared materials were about 15 nm through X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Gas response characteristics were examined for formaldehyde (HCHO), benzene, carbon monoxide, carbon dioxide gas existing in building. In particular, the sensors showed responses to HCHO gas at sub ppm as a function of operating temperatures and gas concentrations. Also, we investigated sensitivity, repeativity, selectivity, and response time of sensor. The transients were very sharp, taking less than 2 s for 90% response. The sensor has shown very stable response at 350 degrees C and followed a very good behavior and showed 60% response in 50 ppb HCHO concentration at 350 degrees C operating temperatures.

  3. Evaluation of soil-gas transport of organic chemicals into residential buildings: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, A.T.; Garbesi, K.; Sextro, R.G.; Daisey, J.M.

    1988-06-01

    This investigation consisted of theoretical, laboratory, and field study phases with the overall objective of determining the importance of pressure-driven flow of soil gas in the transport of volatile organic compounds (VOC) from soil into a house. In the first phase, the mechanisms of advection, diffusion, and retardation of VOC in soil were evaluated. Using the theory of fluid mechanics and empirical for equilibrium partitioning of VOC among gas, aqueous, and solid phase of soil, a one-dimensional advection-diffusion equation or the transport of gas-phase VOC through soil was developed. An experimental apparatus and method were developed for the direct observation of pressure-driven transport of VOC through soil under controlled laboratory conditions. The retardation of sulfur hexafluoride (SF/sub 6/) and hexafluorobenzene with respect to the flow of the bulk gas was measured in soil-column experiments using different soils and soil-moisture conditions. The results were in good agreement with theoretical predictions. Since SF/sub 6/ was not lost by sorption to soil, it was selected for use as a tracer gas in the field study to study the advective flow of soil gas. The overall objective of the investigation was directly addressed by the field study. This study was conducted at a house which has a basement and which was located adjacent to a covered municipal landfill. The soil at the site was characterized, pressure coupling between the basement and surrounding soil was measured, the entry rate of soil gas as a function of basement depressurization was measured, and VOC in soil gas, indoor air and outdoor air were quantified. 46 refs., 18 figs., 11 tabs.

  4. Performance of an electrothermal swing adsorption system with postdesorption liquefaction for organic gas capture and recovery.

    Science.gov (United States)

    Mallouk, Kaitlin E; Rood, Mark J

    2013-07-02

    The use of adsorption on activated carbon fiber cloth (ACFC) followed by electrothermal swing adsorption (ESA) and postdesorption pressure and temperature control allows organic gases with boiling points below 0 °C to be captured from air streams and recovered as liquids. This technology has the potential to be a more sustainable abatement technique when compared to thermal oxidation. In this paper, we determine the process performance and energy requirements of a gas recovery system (GRS) using ACFC-ESA for three adsorbates with relative pressures between 8.3 × 10(-5) and 3.4 × 10(-3) and boiling points as low as -26.3 °C. The GRS is able to capture > 99% of the organic gas from the feed air stream, which is comparable to destruction efficiencies for thermal oxidizers. The energy used per liquid mole recovered ranges from 920 to 52,000 kJ/mol and is a function of relative pressure of the adsorbate in the feed gas. Quantifying the performance of the bench-scale gas recovery system in terms of its ability to remove organic gases from the adsorption stream and the energy required to liquefy the recovered organic gases is a critical step in developing new technologies to allow manufacturing to occur in a more sustainable manner. To our knowledge, this is the first time an ACFC-ESA system has been used to capture, recover, and liquefy organic compounds with vapor pressures as low as 8.3 × 10(-5) and the first time such a system has been analyzed for process performance and energy consumption.

  5. Plasmonic nanopatch array with integrated metal-organic framework for enhanced infrared absorption gas sensing

    Science.gov (United States)

    Chong, Xinyuan; Kim, Ki-joong; Zhang, Yujing; Li, Erwen; Ohodnicki, Paul R.; Chang, Chih-Hung; Wang, Alan X.

    2017-06-01

    In this letter, we present a nanophotonic device consisting of plasmonic nanopatch array (NPA) with integrated metal-organic framework (MOF) for enhanced infrared absorption gas sensing. By designing a gold NPA on a sapphire substrate, we are able to achieve enhanced optical field that spatially overlaps with the MOF layer, which can adsorb carbon dioxide (CO2) with high capacity. Experimental results show that this hybrid plasmonic-MOF device can effectively increase the infrared absorption path of on-chip gas sensors by more than 1100-fold. The demonstration of infrared absorption spectroscopy of CO2 using the hybrid plasmonic-MOF device proves a promising strategy for future on-chip gas sensing with ultra-compact size.

  6. Microbial electrolysis cells for high yield hydrogen gas production from organic matter.

    Science.gov (United States)

    Logan, Bruce E; Call, Douglas; Cheng, Shaoan; Hamelers, Hubertus V M; Sleutels, Tom H J A; Jeremiasse, Adriaan W; Rozendal, René A

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (> 0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment.

  7. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    KAUST Repository

    Logan, Bruce E.

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment. © 2008 American Chemical Society.

  8. Metal-Organic Framework Thin Films as Stationary Phases in Microfabricated Gas-Chromatography Columns.

    Energy Technology Data Exchange (ETDEWEB)

    Read, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sillerud, Colin Halliday [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    The overarching goal of this project is to integrate Sandia's microfabricated gas-chromatography ( GC) columns with a stationary phase material that is capable of retaining high-volatility chemicals and permanent gases. The successful integration of such a material with GCs would dramatically expand the repertoire of detectable compounds for Sandia's various microanalysis systems. One such promising class of candidate materials is metal-organic frameworks (MOFs). In this report we detail our methods for controlled deposition of HKUST-1 MOF stationary phases within GC columns. We demonstrate: the chromatographic separation of natural gas; a method for determining MOF film thickness from chromatography alone; and the first-reported GC x GC separation of natural gas -- in general -- let alone for two disparate MOF stationary phases. In addition we determine the fundamental thermodynamic constant for mass sorption, the partition coefficient, for HKUST-1 and several light hydrocarbons and select toxic industrial chemicals.

  9. Investigation of the effect of pore size on gas uptake in two metal-organic frameworks.

    Science.gov (United States)

    Wang, Rongming; Meng, Qingguo; Zhang, Liangliang; Wang, Haifeng; Dai, Fangna; Guo, Wenyue; Zhao, Lianming; Sun, Daofeng

    2014-05-18

    Two porous metal–organic frameworks (1 and 2) with a fsc topology based on mixed ligands have been assembled and characterized. The different pillared ligands (pyrazine for 1 and 4,4′-bipyridine for 2) significantly influence the pore size of the frameworks. Gas uptake measurements reveal that complex 1 possesses higher H2, CO2, and CH4 uptake capacities than 2, although the surface area of 1 is lower than that of complex 2. These results further experimentally prove that the pore size plays an important role in gas uptake in porous MOFs, and the slit pore with a size of ~6 Å exhibits stronger interactions with gas molecules.

  10. Capture of elemental and organic iodine from dilute gas streams by silver-exchanged mordenite

    Energy Technology Data Exchange (ETDEWEB)

    Bruffey, S.H.; Jubin, R.T.; Jordan, J.A. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States)

    2016-07-01

    The treatment of off-gas streams arising from reprocessing of used nuclear fuel (UNF) is an area of active study by the U.S. Department of Energy. Such off-gas streams contain volatile fission products, including long-lived {sup 129}I. Although {sup 129}I is released into the off-gas at multiple points within the chemical reprocessing flowsheet, previous research has focused on removal from the dissolver off-gas stream (DOG). The DOG is expected to contain up to 98% of iodine in UNF at ppm levels within the stream. Other off-gas streams will also contain iodine but at substantially lower concentrations. Recent work has shown that compliance with U.S. regulations will likely require capture of iodine from these dilute streams in addition to capture from DOG. In particular, the vessel off-gas (VOG) stream is expected to contain 1-3% of the total iodine inventory at ppb concentrations. A review of literature also indicates that the speciation of iodine in the VOG stream will differ from that of the DOG, with the DOG containing primarily I{sub 2} and the VOG containing a mixture of I{sub 2} and organic iodine species. Silver-exchanged mordenite (AgZ) has been identified for use in the removal of iodine from off-gas streams. It is an effective capture material for I{sub 2} at the concentrations expected in the DOG, but little is known about its performance in gas streams that may contain both I{sub 2} and organic iodides at very dilute concentrations. The experiments to be described were designed to separately characterize the adsorption of I{sub 2} and methyl iodide on AgZ through extended duration testing. Simulated vessel off-gases containing low levels of either I{sub 2} or methyl iodide were contacted with AgZ sorbent beds for up to four months. Through the use of sorbent beds in series and varied sampling times, key parameters such as adsorption rate, decontamination factor, and performance over time could be determined for the capture of each species by AgZ. This

  11. An Innovative Organic Rankine Cycle wtih Gas-liquid Injector for Pressurization

    Institute of Scientific and Technical Information of China (English)

    ZHU Hua-yun; XU Zhi-ming

    2016-01-01

    The organic Rankine cycle ( ORC ) is an effective way to recycle low temperature exhaust heat but pump for the ORC has several disadvantages such as great difficulty in manufacturing , easily-invited cavitations , low efficiency and high cost .Gas-liquid two-phase injector is a device without moving parts , in which steam is used to drive cold liquid from a pressure lower than the primary steam to a pressure higher than the primary steam.In this paper , the mechanical circulation pump was replaced with a gas-liquid injector .The effect of the evaporate temperature for the system was studied with the organic fluid R 123.While this novel ORC can not only improves the energy utilization , but also be suitable for some occasions without power .

  12. Organic and inorganic composition and microbiology of produced waters from Pennsylvania shale gas wells

    Science.gov (United States)

    Akob, Denise M.; Cozzarelli, Isabelle M.; Dunlap, Darren S.; Rowan, Elisabeth L.; Lorah, Michelle M.

    2015-01-01

    Hydraulically fractured shales are becoming an increasingly important source of natural gas production in the United States. This process has been known to create up to 420 gallons of produced water (PW) per day, but the volume varies depending on the formation, and the characteristics of individual hydraulic fracture. PW from hydraulic fracturing of shales are comprised of injected fracturing fluids and natural formation waters in proportions that change over time. Across the state of Pennsylvania, shale gas production is booming; therefore, it is important to assess the variability in PW chemistry and microbiology across this geographical span. We quantified the inorganic and organic chemical composition and microbial communities in PW samples from 13 shale gas wells in north central Pennsylvania. Microbial abundance was generally low (66–9400 cells/mL). Non-volatile dissolved organic carbon (NVDOC) was high (7–31 mg/L) relative to typical shallow groundwater, and the presence of organic acid anions (e.g., acetate, formate, and pyruvate) indicated microbial activity. Volatile organic compounds (VOCs) were detected in four samples (∼1 to 11.7 μg/L): benzene and toluene in the Burket sample, toluene in two Marcellus samples, and tetrachloroethylene (PCE) in one Marcellus sample. VOCs can be either naturally occurring or from industrial activity, making the source of VOCs unclear. Despite the addition of biocides during hydraulic fracturing, H2S-producing, fermenting, and methanogenic bacteria were cultured from PW samples. The presence of culturable bacteria was not associated with salinity or location; although organic compound concentrations and time in production were correlated with microbial activity. Interestingly, we found that unlike the inorganic chemistry, PW organic chemistry and microbial viability were highly variable across the 13 wells sampled, which can have important implications for the reuse and handling of these fluids

  13. Formation of complex organic molecules in cold objects: the role of gas phase reactions

    OpenAIRE

    Balucani, Nadia; Ceccarelli, Cecilia; Taquet, Vianney

    2015-01-01

    While astrochemical models are successful in reproducing many of the observed interstellar species, they have been struggling to explain the observed abundances of complex organic molecules. Current models tend to privilege grain surface over gas phase chemistry in their formation. One key assumption of those models is that radicals trapped in the grain mantles gain mobility and react on lukewarm (>30 K) dust grains. Thus, the recent detections of methyl formate (MF) and dimethyl ether (DME) ...

  14. Analysis of impulse electric field effect on organic exhaust gas decomposition

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The technique of organic exhaust gas decomposition with impulse corono-dischrge plasma has been investigated in this study. It has been discovered that the impulse electric fieldaffected the decomposition efficiency with the secondary electron emission coefficient (δ of the corona electrode as an intermediate: when W was fixed the corona electrode material with higher δcould induce higher decomposition efficiency. In these experiments,wolfram electrode which has the highest δhas really induced the highest decomposition efficiency.

  15. Metal-Organic Frameworks for Sensing Applications in the Gas Phase

    Directory of Open Access Journals (Sweden)

    Sabine Achmann

    2009-03-01

    Full Text Available Several metal-organic framework (MOF materials were under investigated to test their applicability as sensor materials for impedimetric gas sensors. The materials were tested in a temperature range of 120 °C - 240 °C with varying concentrations of O2, CO2, C3H8, NO, H2, ethanol and methanol in the gas atmosphere and under different test gas humidity conditions. Different sensor configurations were studied in a frequency range of 1 Hz -1 MHz and time-continuous measurements were performed at 1 Hz. The materials did not show any impedance response to O2, CO2, C3H8, NO, or H2 in the gas atmospheres, although for some materials a significant impedance decrease was induced by a change of the ethanol or methanol concentration in the gas phase. Moreover, pronounced promising and reversible changes in the electric properties of a special MOF material were monitored under varying humidity, with a linear response curve at 120 °C. Further investigations were carried out with differently doped MOF materials of this class, to evaluate the influence of special dopants on the sensor effect.

  16. Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

    Science.gov (United States)

    Gentner, D. R.; Ford, T. B.; Guha, A.; Boulanger, K.; Brioude, J.; Angevine, W. M.; de Gouw, J. A.; Warneke, C.; Gilman, J. B.; Ryerson, T. B.; Peischl, J.; Meinardi, S.; Blake, D. R.; Atlas, E.; Lonneman, W. A.; Kleindienst, T. E.; Beaver, M. R.; St. Clair, J. M.; Wennberg, P. O.; VandenBoer, T. C.; Markovic, M. Z.; Murphy, J. G.; Harley, R. A.; Goldstein, A. H.

    2014-05-01

    Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. It is essential to understand the emissions and air quality impacts of these relatively understudied sources, especially for oil/gas operations in light of increasing US production. Ground site measurements in Bakersfield and regional aircraft measurements of reactive gas-phase organic compounds and methane were part of the CalNex (California Research at the Nexus of Air Quality and Climate Change) project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions, and provide average source profiles. To examine the spatial distribution of emissions in the San Joaquin Valley, we developed a statistical modeling method using ground-based data and the FLEXPART-WRF transport and meteorological model. We present evidence for large sources of paraffinic hydrocarbons from petroleum operations and oxygenated compounds from dairy (and other cattle) operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes, most of which have limited previous in situ measurements or characterization in petroleum operation emissions. Observed dairy emissions were dominated by ethanol, methanol, acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The petroleum operations source profile was developed using the composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil. The observed source profile is

  17. Gas cluster ion beam for the characterization of organic materials in submarine basalts as Mars analogs

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Naoko, E-mail: naoko.sano@ncl.ac.uk; Barlow, Anders J.; Cumpson, Peter J. [National EPSRC XPS Users' Service (NEXUS), School of Mechanical and Systems Engineering, Stephenson Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom); Purvis, Graham W. H.; Abbott, Geoffrey D.; Gray, Neil N. D. [School of Civil Engineering and Geosciences, Devonshire Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom)

    2016-07-15

    The solar system contains large quantities of organic compounds that can form complex molecular structures. The processing of organic compounds by biological systems leads to molecules with distinctive structural characteristics; thus, the detection and characterization of organic materials could lead to a high degree of confidence in the existence of extra-terrestrial life. Given the nature of the surface of most planetary bodies in the solar system, evidence of life is more likely to be found in the subsurface where conditions are more hospitable. Basalt is a common rock throughout the solar system and the primary rock type on Mars and Earth. Basalt is therefore a rock type that subsurface life might exploit and as such a suitable material for the study of methods required to detect and analyze organic material in rock. Telluric basalts from Earth represent an analog for extra-terrestrial rocks where the indigenous organic matter could be analyzed for molecular biosignatures. This study focuses on organic matter in the basalt with the use of surface analysis techniques utilizing Ar gas cluster ion beams (GCIB); time of flight secondary ion mass spectrometry (ToF-SIMS), and x-ray photoelectron spectroscopy (XPS), to characterize organic molecules. Tetramethylammonium hydroxide (TMAH) thermochemolysis was also used to support the data obtained using the surface analysis techniques. The authors demonstrate that organic molecules were found to be heterogeneously distributed within rock textures. A positive correlation was observed to exist between the presence of microtubule textures in the basalt and the organic compounds detected. From the results herein, the authors propose that ToF-SIMS with an Ar GCIB is effective at detecting organic materials in such geological samples, and ToF-SIMS combined with XPS and TMAH thermochemolysis may be a useful approach in the study of extra-terrestrial organic material and life.

  18. Doubled volatile organic compound emissions from subarctic tundra under simulated climate warming

    DEFF Research Database (Denmark)

    Faubert, Patrick; Tiiva, Paivi; Rinnan, Åsmund

    2010-01-01

    • Biogenic volatile organic compound (BVOC) emissions from arctic ecosystems are important in view of their role in global atmospheric chemistry and unknown feedbacks to global warming. These cold ecosystems are hotspots of climate warming, which will be more severe here than averaged over...... of a focus on BVOC emissions during climate change. The observed changes have implications for ecological interactions and feedback effects on climate change via impacts on aerosol formation and indirect greenhouse effects....... the globe. We assess the effects of climatic warming on non-methane BVOC emissions from a subarctic heath. • We performed ecosystem-based chamber measurements and gas chromatography-mass spectrometry (GC-MS) analyses of the BVOCs collected on adsorbent over two growing seasons at a wet subarctic tundra...

  19. In situ search for organics by gas chromatography analysis: new derivatization / thermochemolysis approach

    Science.gov (United States)

    Geffroy, Claude; Buch, Arnaud; David, Marc; Aissat, Lyes; El Mufleh, Amel; Papot, S.; Sternberg, Robert

    Many organic molecules are present in interstellar clouds and might be carried to the early Earth by comets and meteorites during the heavy bombardment phase in the first few hundred million years of the solar system. It has been suggested that extraterrestrial organic material may well represent an important part of the organic material available for the origin of life. Until samples, brought by future space missions, are available on Earth, in situ measurements are one of the way to get unaltered and non-contaminated samples for analysis. The analytical technique has to be robust, sensitive and non-specific due to the large scope of targets molecules. The only currently flight qualified technique of analysis of organic molecules in space is gas chromatography (Viking, Cassini-Huygens, SAM-MSL, COSAC-Rosetta). The main objective of this work is to present a new approach with multi step analysis using derivatisation and thermochemolysis reagents for a one pot in situ analysis of volatile and refractory organics in surface or sub-surface samples (Mars, comets).Indeed, no single technology enables to identify all organic compounds because naturally occurring molecules have different polarities, molecular weights, being extractible or recalcitrant, bonded trapped or adsorbed on minerals. Thus, we propose to wider the scope of chemical reagent already validated for in situ wet chemistry such as MTBSTFA (Rodier et al. 2001, 2002), DMF-DMA (Rodier et al. 2002), or TMAH (Rodier et al, 2005, Geffroy-Rodier et al; 2009) to analyze enantiomers of amino acids, carbohydrates and lipids in a one pot several steps sub system using a multi reagent and multi step approach. Thus using a new derivatizing agent, we successfully identified twenty one amino acids including twelve of the twenty proteinic amino acids without inhibiting following multi step thermochemolysis. *Geffroy-Rodier C, Grasset L, Sternberg R. Buch A. Amblès A. (2009) Thermochemolysis in search for organics in

  20. Organic Amendment Effects on Greenhouse Gas Emissions from Long-Term Stockpiled Soils

    Science.gov (United States)

    Zvomuya, F.; Laskosky, J.

    2014-12-01

    In oil sands projects in Alberta, Canada, salvaged soils are often placed in large stockpiles where they are stored for the duration of the project, typically 20-30 years. Alberta regulations require that topsoil and subsoil are salvaged in two distinct operations - a process known as two-lifting. Reclamation using long-term stockpiled soils often gives poor results, characterized by lower soil organic carbon and nitrogen concentrations compared with equivalent natural, undisturbed soils. It is thought that the change from an aerobic to an anaerobic environment during soil stockpiling and back again to aerobic during placement are largely responsible for the low carbon and nitrogen due to microbial activity transforming C and N in the soil into CO2, CH4 and N2O and releasing them to the atmosphere. Evidence from recent studies indicates that biochar improves soil physical, chemical and biological properties, and hence could mitigate C and N losses due to greenhouse gas emissions from the soil indirectly. We postulate that documented improvements in soil physical, chemical, and biological properties in soils treated with amendments such as biochar may help mitigate C and N losses due to greenhouse gas emissions from the soil indirectly. This laboratory incubation experiment tested the effects of differential rates (0, 10, 20, and 40 g biochar carbon equivalents kg-1 dry soil) of biochar, peat, and humalite on greenhouse gas emissions from a 25-year old two-lift stockpiled soil. The soils were fertilized according to standard practice, placed in 120-mL plastic containers, and incubated at 25°C for 45 days. Gas samples were taken at 1- to 7-day intervals and analyzed for CO2, CH4, and N2O. Data on treatment differences in emissions will be presented. Results from this experiment will provide an insight into the potential for organic amendments to mitigate greenhouse gas emission during reclamation using degraded soils.

  1. Design and Analysis of SAW Based MEMS Gas Sensor for the Detection of Volatile Organic Gases

    Directory of Open Access Journals (Sweden)

    Staline Johnson

    2014-03-01

    Full Text Available This paper portrays the design and analysis of SAW based MEMS gas sensor for the detection of volatile organic gases. The gas sensor consists of interdigitated transducers modeled on a piezoelectric substrate and covered by a thin film of polyisobutylene (PIB which acts as the sensing layer. The piezoelectric substrate material used is YZ cut Lithium Niobate (LiNbO3 and electrodes used are made of Aluminium (Al. Mass loading effect on the sensing layer is used for the detection of volatile organic gases. The design and simultions were carried out by using comsol multiphysics software based on Finite Element Method (FEM for analytical simulations. The resonant frequency of the SAW device was determined and simulations are carried out by exposing the sensor to 100 ppm of various volatile organic gases and corresponding shift in resonant frequency for various gases are determined. The reduction in the resonant frequency is used for the detection of volatile organic gases such as chloromethane, dichloromethane, trichloromethane, tetrachloroethene, carbon tetrachloride and trichloroethylene.

  2. Cochlear condition and olivocochlear system of gas station attendants exposed to organic solvents

    Directory of Open Access Journals (Sweden)

    Tochetto, Tania Maria

    2012-01-01

    Full Text Available Introduction: Organic solvents have been increasingly studied due to its ototoxic action. Objective: Evaluate the conditions of outer hair cells and olivocochlear system in individuals exposed to organic solvents. Method: This is a prospective study. 78 gas station attendants exposed to organic solvents had been evaluated from three gas stations from Santa Maria city, Rio Grande do Sul (RS. After applying the inclusion criteria, the sample was constituted by 24 individuals. The procedures used on the evaluation were audiological anamnesis, Transient otoacoustic emissions (TEOAES and research for the suppressive effect of TEOAES. A group control (GC compounded by 23 individuals was compared to individuals exposed and non-exposed individuals. The data collection has been done in the room of Speech Therapy of Workers Health Reference Center of Santa Maria. Results: The TEOAES presence was major in the left ear in both groups; the average relation of TEOAES signal/noise in both ears was greater in GE; the TEOAES suppressive effect in the right ear was higher in the individual of GE (62,5% and in the left ear was superior in GC (86,96%, with statistically significant difference. The median sign/noise ratio of TEOAES, according to the frequency range, it was higher in GC in three frequencies ranges in the right ear and one in the left ear. Conclusion: It was not found signs of alteration on the outer hair cells neither on the olivocochlear medial system in the individuals exposed to organic solvents.

  3. Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

    Science.gov (United States)

    P. Veres; J. B. Gilman; J. M. Roberts; W. C. Kuster; C. Warneke; I. R. Burling; J. de Gouw

    2010-01-01

    We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs). The Mobile Organic Carbon Calibration System (MOCCS) combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC) conversion on a palladium surface to CO2 in the presence of...

  4. CO2 Storage by Sorption on Organic Matter and Clay in Gas Shale

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, Diana H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yonkofski, Catherine MR [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schaef, Herbert T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); White, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-10

    Simulations of methane production and supercritical carbon dioxide injection were developed that consider competitive adsorption of CH4 and CO2 on both organic matter and montmorillonite. The results were used to assess the potential for storage of CO2 in a hydraulically fractured shale gas reservoir and for enhanced recovery of CH4. Assuming equal volume fractions of organic matter and montmorillonite, amounts of CO2 adsorbed on both materials were comparable, while methane desorption was from clays was two times greater than desorption from organic material. The most successful strategy considered CO2 injection from a separate well and enhanced methane recovery by 73%, while storing 240 kmt of CO2.

  5. Angle dependence of argon gas cluster sputtering yields for organic materials.

    Science.gov (United States)

    Seah, M P; Spencer, S J; Shard, A G

    2015-02-19

    The first angle-dependent measurements of the sputtering yield of an organic material using argon gas cluster ions under a wide range of conditions are reported in order to develop an analytical description of the behavior important for the development of the application of secondary ion mass spectrometry to organic and biological systems. Data are presented for Irganox 1010 using argon gas cluster ion beams of 5 and 10 keV energy, E, with cluster sizes, n, from 1000 to 5000. The measurements are conducted in an X-ray photoelectron spectrometer for a range of angles from 0 to 80° from the surface normal. The results support the Universal Equation for argon gas cluster sputtering yields with the angle dependence incorporated into the equation via a simple angle dependence of the parameter A. This explains how and why the angular dependence of the sputtering yield changes significantly with increasing E/n. These results are also accurately confirmed using the published measurements for polystyrene by Rading et al.

  6. Formation of complex organic molecules in cold objects: the role of gas phase reactions

    CERN Document Server

    Balucani, Nadia; Taquet, Vianney

    2015-01-01

    While astrochemical models are successful in reproducing many of the observed interstellar species, they have been struggling to explain the observed abundances of complex organic molecules. Current models tend to privilege grain surface over gas phase chemistry in their formation. One key assumption of those models is that radicals trapped in the grain mantles gain mobility and react on lukewarm (>30 K) dust grains. Thus, the recent detections of methyl formate (MF) and dimethyl ether (DME) in cold objects represent a challenge and may clarify the respective role of grain surface and gas phase chemistry. We propose here a new model to form DME and MF with gas phase reactions in cold environments, where DME is the precursor of MF via an efficient reaction overlooked by previous models. Furthermore, methoxy, a precursor of DME, is also synthetized in the gas phase from methanol, which is desorbed by a non-thermal process from the ices. Our new model reproduces fairy well the observations towards L1544. It also...

  7. Observations of gas- and aerosol-phase organic nitrates at BEACHON-RoMBAS 2011

    Directory of Open Access Journals (Sweden)

    J. L. Fry

    2013-09-01

    Full Text Available At the Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS field campaign in the Colorado front range, July–August 2011, measurements of gas- and aerosol-phase organic nitrates enabled a study of the role of NOx (NOx = NO + NO2 in oxidation of forest-emitted volatile organic compounds (VOCs and subsequent aerosol formation. Substantial formation of peroxy- and alkyl-nitrates is observed every morning, with an apparent 2.9% yield of alkyl nitrates from daytime RO2 + NO reactions. Aerosol-phase organic nitrates, however, peak in concentration during the night, with concentrations up to 140 ppt as measured by both optical spectroscopic and mass spectrometric instruments. The diurnal cycle in aerosol fraction of organic nitrates shows an equilibrium-like response to the diurnal temperature cycle, suggesting some reversible absorptive partitioning, but the full dynamic range cannot be reproduced by thermodynamic repartitioning alone. Nighttime aerosol organic nitrate is observed to be positively correlated with [NO2] × [O3] but not with [O3]. These observations support the role of nighttime NO3-initiated oxidation of monoterpenes as a significant source of nighttime aerosol. Nighttime production of organic nitrates is comparable in magnitude to daytime photochemical production at this site, which we postulate to be representative of the Colorado front range forests.

  8. Temperature dependence of the particle/gas partition coefficient: An application to predict indoor gas-phase concentrations of semi-volatile organic compounds.

    Science.gov (United States)

    Wei, Wenjuan; Mandin, Corinne; Blanchard, Olivier; Mercier, Fabien; Pelletier, Maud; Le Bot, Barbara; Glorennec, Philippe; Ramalho, Olivier

    2016-09-01

    The indoor gas-phase concentrations of semi-volatile organic compounds (SVOCs) can be predicted from their respective concentrations in airborne particles by applying the particle/gas partitioning equilibrium. The temperature used for partitioning is often set to 25°C. However, indoor temperatures frequently differ from this reference value. This assumption may result in errors in the predicted equilibrium gas-phase SVOC concentrations. To improve the prediction model, the temperature dependence of the particle/gas partition coefficient must be addressed. In this paper, a theoretical relationship between the particle/gas partition coefficient and temperature was developed based on the SVOC absorptive mechanism. The SVOC particle/gas partition coefficients predicted by employing the derived theoretical relationship agree well with the experimental data retrieved from the literature (R>0.93). The influence of temperature on the equilibrium gas-phase SVOC concentration was quantified by a dimensionless analysis of the derived relationship between the SVOC particle/gas partition coefficient and temperature. The predicted equilibrium gas-phase SVOC concentration decreased by between 31% and 53% when the temperature was lowered by 6°C, while it increased by up to 750% when the indoor temperature increased from 15°C to 30°C.

  9. Temperature dependence of the particle/gas partition coefficient: An application to predict indoor gas-phase concentrations of semi-volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Wenjuan, E-mail: Wenjuan.Wei@cstb.fr [University of Paris-Est, Scientific and Technical Center for Building (CSTB), Health and Comfort Department, French Indoor Air Quality Observatory (OQAI), 84 Avenue Jean Jaurès, Champs sur Marne, 77447 Marne la Vallée Cedex 2 (France); Mandin, Corinne [University of Paris-Est, Scientific and Technical Center for Building (CSTB), Health and Comfort Department, French Indoor Air Quality Observatory (OQAI), 84 Avenue Jean Jaurès, Champs sur Marne, 77447 Marne la Vallée Cedex 2 (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); Blanchard, Olivier [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Mercier, Fabien [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Pelletier, Maud [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Le Bot, Barbara [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); and others

    2016-09-01

    The indoor gas-phase concentrations of semi-volatile organic compounds (SVOCs) can be predicted from their respective concentrations in airborne particles by applying the particle/gas partitioning equilibrium. The temperature used for partitioning is often set to 25 °C. However, indoor temperatures frequently differ from this reference value. This assumption may result in errors in the predicted equilibrium gas-phase SVOC concentrations. To improve the prediction model, the temperature dependence of the particle/gas partition coefficient must be addressed. In this paper, a theoretical relationship between the particle/gas partition coefficient and temperature was developed based on the SVOC absorptive mechanism. The SVOC particle/gas partition coefficients predicted by employing the derived theoretical relationship agree well with the experimental data retrieved from the literature (R > 0.93). The influence of temperature on the equilibrium gas-phase SVOC concentration was quantified by a dimensionless analysis of the derived relationship between the SVOC particle/gas partition coefficient and temperature. The predicted equilibrium gas-phase SVOC concentration decreased by between 31% and 53% when the temperature was lowered by 6 °C, while it increased by up to 750% when the indoor temperature increased from 15 °C to 30 °C. - Highlights: • A theoretical relationship between K{sub p} and temperature was developed. • The relationship was based on the SVOC absorptive mechanism. • The temperature impact was quantified by a dimensionless analysis.

  10. Sensitive resonant gas sensor operating in air with metal organic frameworks coating

    KAUST Repository

    Jaber, Nizar

    2017-08-09

    We report a practical resonant gas sensor that is uniformly coated with metal organic frameworks (MOFs) and excited near the higher order modes for a higher attained sensitivity. The resonator is based on an electrostatically excited clamped-clamped microbeam. The microbeam is fabricated from a polyimide layer coated from the top with Cr/Au and from the bottom with Cr/Au/Cr layer. The geometry of the resonator is optimized to reduce the effect of the squeeze film damping, thereby allowing operation under atmospheric pressure. The electrostatic force electrode is designed to enhance the excitation of the second mode of vibration with the minimum power required. Significant frequency shift (kHz) is demonstrated for the first time upon water vapor, acetone, and ethanol exposure due to the MOFs functionalization and the higher order modes excitation. Also, the adsorption dynamics and MOF selectivity is investigated by studying the decaying time constants of the response upon gas exposure.

  11. Properties of two-dimensional electron gas containing self-organized quantum antidots

    Science.gov (United States)

    Vasilyev, Yu.; Suchalkin, S.; Zundel, M.; Heisenberg, D.; Eberl, K.; von Klitzing, K.

    1999-11-01

    A nonuniform two-dimensional electron gas in a heterojunction with inserted self-organized electrically inactive dots (acting as antidots) has been fabricated by molecular-beam epitaxy of AlGaAs/AlInAs/GaAs layer sequences. Transport measurements give the ratio of the transport mobility to the quantum mobility less than four, which suggests that the dominant scattering at low magnetic fields is the short-range scattering from the lateral potential of the antidots. Far-infrared cyclotron resonance (CR) spectra show an absorption mode as narrow as 0.5 cm-1 at high magnetic fields associated with the high-mobility electron gas formed between the antidot islands and confined in the lateral directions. The confinement energy of 14 cm-1 is derived from the CR spectra.

  12. Dynamic self-organization phenomena in complex ionized gas systems: new paradigms and technological aspects

    Science.gov (United States)

    Vladimirov, S. V.; Ostrikov, K.

    2004-04-01

    An overview of dynamic self-organization phenomena in complex ionized gas systems, associated physical phenomena, and industrial applications is presented. The most recent experimental, theoretical, and modeling efforts to understand the growth mechanisms and dynamics of nano- and micron-sized particles, as well as the unique properties of the plasma-particle systems (colloidal, or complex plasmas) and the associated physical phenomena are reviewed and the major technological applications of micro- and nanoparticles are discussed. Until recently, such particles were considered mostly as a potential hazard for the microelectronic manufacturing and significant efforts were applied to remove them from the processing volume or suppress the gas-phase coagulation. Nowadays, fine clusters and particulates find numerous challenging applications in fundamental science as well as in nanotechnology and other leading high-tech industries.

  13. Analysis of volatile organic compounds in water by dynamic stripping, thermal desorption, cryofocusing, and capillary gas chromatography (journal version)

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, S.A.

    1988-01-01

    A dynamic headspace procedure developed for the determination of volatile organic compounds (VOCs) in water is described. The VOCs are purged from a water sample with an inert gas, transferring them to a tube packed with Tenax adsorbent. The adsorbent tube, or trap, is thermally desorbed, the analytes cryofocused, and subsequently transferred to a capillary column gas chromatograph.

  14. Secondary Organic Aerosol formation from the gas-phase reaction of catechol with ozone

    Science.gov (United States)

    Coeur-Tourneur, C.; Tomas, A.; Guilloteau, A.; Henry, F.; Ledoux, F.; Visez, N.; Riffault, V.; Wenger, J. C.; Bedjanian, Y.; Foulon, V.

    2009-04-01

    The formation of secondary organic aerosol from the gas-phase reaction of catechol (1,2-dihydroxybenzene) with ozone has been studied in two smog chambers (at the LPCA in France and at the CRAC in Ireland). Aerosol production was monitored using a scanning mobility particle sizer. The overall organic aerosol yield (Y) was determined as the ratio of the suspended aerosol mass corrected for wall losses (Mo) to the total reacted catechol concentrations, assuming a particle density of 1.4 g cm-3. Analysis of the data clearly shows that Y is a strong function of Mo and that secondary organic aerosol formation can be expressed by a one-product gas/particle partitioning absorption model. The aerosol formation is affected by the initial catechol concentration, which leads to aerosol yields ranging from 17% to 86%. The aerosol yields determined in the LPCA and CRAC smog chambers were comparable and were also in accordance with those determined in a previous study performed in EUPHORE (EUropean PHOto REactor, Spain).

  15. Effort Optimization in Minimizing Food Related Greenhouse Gas Emissions, a look at "Organic" and "Local"

    Science.gov (United States)

    Bowen, E.; Martin, P. A.; Eshel, G.

    2008-12-01

    The adverse environmental effects, especially energy use and resultant GHG emissions, of food production and consumption are becoming more widely appreciated and increasingly well documented. Our insights into the thorny problem of how to mitigate some of those effects, however, are far less evolved. Two of the most commonly advocated strategies are "organic" and "local", referring, respectively, to growing food without major inputs of fossil fuel based synthetic fertilizers and pesticides and to food consumption near its agricultural origin. Indeed, both agrochemical manufacture and transportation of produce to market make up a significant percentage of energy use in agriculture. While there can be unique environmental benefits to each strategy, "organic" and "local" each may potentially result in energy and emissions savings relative to conventionally grown produce. Here, we quantify the potential energy and greenhouse gas emissions savings associated with "organic" and "local". We take note of energy use and actual GHG costs of the major synthetic fertilizers and transportation by various modes routinely employed in agricultural distribution chains, and compare them for ~35 frequently consumed nutritional mainstays. We present new, current, lower-bound energy and greenhouse gas efficiency estimates for these items and compare energy consumption and GHG emissions incurred during producing those food items to consumption and emissions resulting from transporting them, considering travel distances ranging from local to continental and transportation modes ranging from (most efficient) rail to (least efficient) air. In performing those calculations, we demonstrate the environmental superiority of either local or organic over conventional foods, and illuminate the complexities involved in entertaining the timely yet currently unanswered, and previously unanswerable, question of "Which is Environmentally Superior, Organic or Local?". More broadly, we put forth a

  16. A comparative analysis of vehicle-related greenhouse gas emissions between organic and conventional dairy production.

    Science.gov (United States)

    Aggestam, Vivianne; Buick, Jon

    2017-08-01

    Agricultural industrialisation and globalisation have steadily increased the transportation of food across the world. In efforts to promote sustainability and self-sufficiency, organic milk producers in Sweden are required to produce a higher level of cattle feed on-farm in the hope that increased self-sufficiency will reduce reliance on external inputs and reduce transport-related greenhouse gas emissions. Using data collected from 20 conventional and 20 organic milk producers in Sweden this paper aims to assess the global warming impact of farmyard vehicles and the transportation of feed produced 'off-farm' in order to compare the impact of vehicle-related emissions from the different production methods. The findings show organic and conventional production methods have different vehicle-related emission outputs that vary according to a reliance on either road transportation or increased farmyard machinery use. Mechanical weeding is more fuel demanding than conventional agrichemical sprayers. However, artificial fertilising is one of the highest farmyard vehicle-related emitters. The general findings show organic milk production emits higher levels of farm vehicle-related emissions that fail to be offset by reduced emissions occurring from international transport emissions. This paper does not propose to cover a comprehensive supply chain carbon footprint for milk production or attempt to determine which method of production has the largest climatic impact. However, it does demonstrate that Sweden's legal requirements for organic producers to produce more feed on-farm to reduce transport emissions have brought emissions back within Sweden's greenhouse gas inventory and raises questions around the effectiveness of policies to reduce vehicle-related emissions. Further research is needed into the effectiveness of climate change mitigation on food production policies, in particular looking at various trade-offs that affects the entire food supply chain.

  17. The role of outlet temperature of flue gas in organic Rankine cycle considering low temperature corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shuang Ying; Li, Chun; Xiao, Lan; Li, You Rong; Liu, Chao [Chongqing University, Chongqing (China)

    2014-12-15

    This paper gives a special focus on the role of outlet temperature of flue gas (T{sub go}) in organic Rankine cycle (ORC) system for low temperature flue gas waste heat recovery. The variations of performance indicators: net work (W{sub net}), exergy efficiency (η{sub ex}) and levelized energy cost (LEC) versus T{sub go} are discussed. Considering the corrosion of low temperature flue gas, the necessity and reasonability of limiting T{sub go} at its minimum allowed discharge temperature (355.15 K) are analyzed. Results show that there exist optimal T{sub go} (T{sub go,opt}) for W{sub net} and LEC, while T{sub go,opt} for η{sub ex} does not appear under the investigated range of T{sub go}. Moreover, the T{sub go,opt} for W{sub net} is always lower than 355.15 K, the T{sub go,opt} for LEC, despite being greater than the one for W{sub net}, is just slightly higher than 355.15 K when the inlet temperature of flue gas varies from 408.15 K to 463.15 K. For the waste heat recovery of low temperature flue gas, it is reasonable to fix T{sub go} at 355.15K if W{sub net} or LEC is selected as primary performance indicator under the pinch point temperature difference of evaporator (ΔT{sub e}) below 20K.

  18. Long-term stability measurements of low concentration Volatile Organic Compound gas mixtures

    Science.gov (United States)

    Allen, Nick; Amico di Meane, Elena; Brewer, Paul; Ferracci, Valerio; Corbel, Marivon; Worton, David

    2017-04-01

    VOCs (Volatile Organic Compounds) are a class of compounds with significant influence on the atmosphere due to their large anthropogenic and biogenic emission sources. VOC emissions have a significant impact on the atmospheric hydroxyl budget and nitrogen reservoir species, while also contributing indirectly to the production of tropospheric ozone and secondary organic aerosol. However, the global budget of many of these species are poorly constrained. Moreover, the World Meteorological Organization's (WMO) Global Atmosphere Watch (GAW) have set challenging data quality objectives for atmospheric monitoring programmes for these classes of traceable VOCs, despite the lack of available stable gas standards. The Key-VOCs Joint Research Project is an ongoing three-year collaboration with the aim of improving the measurement infrastructure of important atmospheric VOCs by providing traceable and comparable reference gas standards and by validating new measurement systems in support of the air monitoring networks. It focuses on VOC compounds that are regulated by European legislation, that are relevant for indoor air monitoring and for air quality and climate monitoring programmes like the VOC programme established by the WMO GAW and the European Monitoring and Evaluation Programme (EMEP). These VOCs include formaldehyde, oxy[genated]-VOCs (acetone, ethanol and methanol) and terpenes (a-pinene, 1,8-cineole, δ-3-carene and R-limonene). Here we present the results of a novel long term stability study for low concentration formaldehyde, oxy-VOC and terpenes gas mixtures produced by the Key-VOCs consortium with discussion regarding the implementation of improved preparation techniques and the use of novel cylinder passivation chemistries to guarantee mixture stability.

  19. A porous Cu(II) metal-organic framework: Synthesis, crystal structure and gas adsorption properties

    Science.gov (United States)

    Li, Wu-Wu; Guo, Ying; Zhang, Wei-Hong

    2017-09-01

    Presented here is a new porous Cu(II) metal-organic framework, namely [Cu(tdc)(H2O)]n·n(DMA) (1 H2tdc = thiophene-2,5-dicarboxylic acid, DMA = N,N‧-dimethylacetamide), which was obtained by the self-assembly reaction of CuCl2 and H2tdc under solvothermal conditions. Single crystal X-ray diffraction analysis revealed that compound 1 features a 3D porous framework based on 1D chain structure subunits, and the 1D rhombohedral channels are occupied by the lattice DMA molecules. Gas adsorption studies reveal that this desolvated sample exhibit high uptake capacity for light hydrocarbons.

  20. Performance analysis of different organic Rankine cycle configurations on board liquefied natural gas-fuelled vessels

    DEFF Research Database (Denmark)

    Baldasso, Enrico; Andreasen, Jesper Graa; Meroni, Andrea

    2017-01-01

    Gas-fuelled shipping is expected to increase significantly in the coming years. Similarly, much effort is devoted to the study of waste heat recovery systems to be implemented on board ships. In this context, the organic Rankine cycle (ORC) technology is considered one of the most promising...... solutions. The ORC favorably compares to the steam Rankine cycle because of its simple layout and high efficiency, achievable by selecting a working fluid with desirable properties. This paper aims at assessing the fuel savings attainable by implementing ORC units on board vessels powered by liquefied...

  1. Organic contamination of ground water at Gas Works Park, Seattle, Washington

    Science.gov (United States)

    Turney, G.L.; Goerlitz, D.F.

    1990-01-01

    Gas Works Park, in Seattle, Washington, is located on the site of a coal and oil gasification plant that ceased operation in 1956. During operation, many types of wastes, including coal, tar, and oil, accumulated on-site. The park soil is currently (1986) contaminated with compounds such as polynuclear aromatic hydrocarbons, volatile organic compounds, trace metals, and cyanide. Analyses of water samples from a network of observation wells in the park indicate that these compounds are also present in the ground water. Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in ground water samples in concentrations as large as 200 mg/L. Concentrations of organic compounds were largest where ground water was in contact with a non-aqueous phase liquid in the soil. Where no non-aqueous phase liquid was present, concentrations were much smaller, even if the ground water was in contact with contaminated soils. This condition is attributed to weathering processes in which soluble, low-molecular-weight organic compounds are preferentially dissolved from the non-aqueous phase liquid into the ground water. Where no non-aqueous phase liquid is present, only stained soils containing relatively insoluble, high-molecular-weight compounds remain. Concentrations of organic contaminants in the soils may still remain large.

  2. Observations of gas- and aerosol-phase organic nitrates at BEACHON-RoMBAS 2011

    Directory of Open Access Journals (Sweden)

    J. L. Fry

    2013-01-01

    Full Text Available At the Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS field campaign in the Colorado front range, July–August 2011, measurements of gas- and aerosol-phase organic nitrates enabled a study of the role of NOx (NOx = NO + NO2 in oxidation of forest-emitted VOCs and subsequent aerosol formation. Substantial formation of peroxy- and alkyl-nitrates is observed every morning, with an apparent 2.9% yield of alkyl nitrates from daytime RO2 + NO reactions. Aerosol-phase organic nitrates, however, peak in concentration during the night, with concentrations up to 140 ppt as measured by both optical spectroscopic and mass spectrometric instruments. The diurnal cycle in aerosol fraction of organic nitrates shows an equilibrium-like response to the diurnal temperature cycle, suggesting some reversible absorptive partitioning, but the full dynamic range cannot be reproduced by thermodynamic repartitioning alone. Nighttime aerosol organic nitrate is observed to be positively correlated with [NO2] × [O3] but not with [O3]. These observations support the role of nighttime NO3-initiated oxidation of monoterpenes as a significant source of nighttime aerosol. Nighttime production of organic nitrates exceeds daytime photochemical production at this site, which we postulate to be representative of the Colorado front range forests.

  3. Harnessing the Power of the Water-Gas Shift Reaction for Organic Synthesis.

    Science.gov (United States)

    Ambrosi, Andrea; Denmark, Scott E

    2016-09-26

    Since its original discovery over a century ago, the water-gas shift reaction (WGSR) has played a crucial role in industrial chemistry, providing a source of H2 to feed fundamental industrial transformations such as the Haber-Bosch synthesis of ammonia. Although the production of hydrogen remains nowadays the major application of the WGSR, the advent of homogeneous catalysis in the 1970s marked the beginning of a synergy between WGSR and organic chemistry. Thus, the reducing power provided by the CO/H2 O couple has been exploited in the synthesis of fine chemicals; not only hydrogenation-type reactions, but also catalytic processes that require a reductive step for the turnover of the catalytic cycle. Despite the potential and unique features of the WGSR, its applications in organic synthesis remain largely underdeveloped. The topic will be critically reviewed herein, with the expectation that an increased awareness may stimulate new, creative work in the area.

  4. Effectiveness of Operation of Organic Rankine Cycle Installation Applied in the Liquid Natural Gas Regasification Plant

    Science.gov (United States)

    Kaczmarek, R.; Stachel, A. A.

    2017-05-01

    An analysis of the operation of an Organic Rankine Cycle (ORC) installation heated by a low-temperature heat source is presented for the case where a condenser of a working fluid is cooled by a liquid of ultralow temperature. For this purpose, the process of regasification of liquid natural gas (LNG) is considered. In the process, the condensation heat of the working fluid in ORC is taken by the LNG evaporating subsequently (i.e., undergoing regasification). The paper presents the schematic of this installation and its application, as well as the results of calculations on the basis of the analysis in terms of the power and efficiency. In the analysis, organic fluids used in the ORC as working ones have been selected.

  5. Carbonyl sulfide as an inverse tracer for biogenic organic carbon in gas and aerosol phases

    Science.gov (United States)

    de Gouw, J. A.; Warneke, C.; Montzka, S. A.; Holloway, J. S.; Parrish, D. D.; Fehsenfeld, F. C.; Atlas, E. L.; Weber, R. J.; Flocke, F. M.

    2009-03-01

    Carbonyl sulfide (COS) is a long-lived trace gas in the atmosphere with an oceanic source and a surface sink through the uptake by vegetation and soils. We demonstrate the use of COS as an inverse tracer for the impact of biogenic emissions on an air mass including the formation of secondary organic aerosol (SOA). Using airborne data from the summer of 2004 over the northeastern U.S., we find that air masses with reduced COS in the continental boundary layer had on average higher mixing ratios of biogenic VOCs (isoprene, monoterpenes, methanol) and their photo-oxidation products (methacrolein, methyl vinyl ketone, methyl furan and MPAN, a peroxyacyl nitrate derived from isoprene). Measurements of water-soluble organic carbon were only weakly correlated with COS, indicating that SOA formation from biogenic precursors was a small contribution to the total.

  6. Highly Reliable Organizations in the Onshore Natural Gas Sector: An Assessment of Current Practices, Regulatory Frameworks, and Select Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Jeffrey S. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paranhos, Elizabeth [Energy Innovation Partners, Seattle, WA (United States); Kozak, Tracy G. [Energy Innovation Partners, Seattle, WA (United States); Boyd, William [Univ. of Colorado, Boulder, CO (United States)

    2017-07-31

    This study focuses on onshore natural gas operations and examines the extent to which oil and gas firms have embraced certain organizational characteristics that lead to 'high reliability' - understood here as strong safety and reliability records over extended periods of operation. The key questions that motivated this study include whether onshore oil and gas firms engaged in exploration and production (E&P) and midstream (i.e., natural gas transmission and storage) are implementing practices characteristic of high reliability organizations (HROs) and the extent to which any such practices are being driven by industry innovations and standards and/or regulatory requirements.

  7. Effect of Organic Amendment Application Rate on Greenhouse Gas Emissions at an Organic Farm in Santa Barbara County, California

    Science.gov (United States)

    Oyewole, M.; King, J. Y.; Cleveland, D. A.

    2015-12-01

    Though greenhouse gas emissions (GHGEs) from mineral fertilizer application in agriculture have been well studied, the effect of organic amendment (OA) application rate on GHGEs is not yet understood. Application of multiple OAs can improve different properties that control soil fertility, including nutrient availability, aggregate stability, and water-holding capacity. We measured nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) flux at an organic farm in Goleta, CA in order to understand how OA application rate affects GHGEs and crop yield from agricultural soils. Based on management practices in the region, we asked farm managers to establish high compost (HC) and low compost (LC) treatments during the growing season of an annual crop (18.2, 9.13 Mg ha-1, respectively), and we measured GHGEs in beds and furrows using static chambers. Organic fertilizer (672 kg ha-1) was applied equally to HC and LC beds six weeks after compost application. Overall, emissions of N2O and CO2 were higher in HC than LC, but yield-scaled emissions were higher in LC. Importantly, treatment differences in both N2O and CO2 emissions were not apparent until after mid-season fertilizer application. Net CH4 uptake was higher in HC than LC in the furrows, but there was no difference in the beds. Our data suggest that high compost application rates likely increased SOM mineralization, soil water content, and nitrification and denitrification rates in HC relative to LC, which led to higher N2O emissions during the growing season. Fertilization primed SOM decomposition and increased soil respiration, which led to increased CO2 emissions. Our results suggest that improved management of application rate and timing during use of multiple OAs could reduce GHGEs while maintaining high crop yield. Understanding the mechanisms by which OA application rates alter the balance between GHGEs and yield is an important step toward reducing agriculture's contribution to climate change through

  8. Carbon Dioxide Removal from Flue Gas Using Microporous Metal Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Lesch, David A

    2010-06-30

    UOP LLC, a Honeywell Company, in collaboration with Professor Douglas LeVan at Vanderbilt University (VU), Professor Adam Matzger at the University of Michigan (UM), Professor Randall Snurr at Northwestern University (NU), and Professor Stefano Brandani at the University of Edinburgh (UE), supported by Honeywell's Specialty Materials business unit and the Electric Power Research Institute (EPRI), have completed a three-year project to develop novel microporous metal organic frameworks (MOFs) and an associated vacuum-pressure swing adsorption (vPSA) process for the removal of CO{sub 2} from coal-fired power plant flue gas. The project leveraged the team's complementary capabilities: UOP's experience in materials development and manufacturing, adsorption process design and process commercialization; LeVan and Brandani's expertise in high-quality adsorption measurements; Matzger's experience in syntheis of MOFs and the organic components associated with MOFs; Snurr's expertise in molecular and other modeling; Honeywell's expertise in the manufacture of organic chemicals; and, EPRI's knowledge of power-generation technology and markets. The project was successful in that a selective CO{sub 2} adsorbent with good thermal stability and reasonable contaminant tolerance was discovered, and a low cost process for flue gas CO{sub 2} capture process ready to be evaluated further at the pilot scale was proposed. The team made significant progress toward the current DOE post-combustion research targets, as defined in a recent FOA issued by NETL: 90% CO{sub 2} removal with no more than a 35% increase in COE. The team discovered that favorable CO{sub 2} adsorption at more realistic flue gas conditions is dominated by one particular MOF structure type, M/DOBDC, where M designates Zn, Co, Ni, or Mg and DOBDC refers to the form of the organic linker in the resultant MOF structure, dioxybenzenedicarboxylate. The structure of the M/DOBDC MOFs

  9. Primary and secondary organic aerosol origin by combined gas-particle phase source apportionment

    Directory of Open Access Journals (Sweden)

    M. Crippa

    2013-08-01

    Full Text Available Secondary organic aerosol (SOA, a prominent fraction of particulate organic mass (OA, remains poorly constrained. Its formation involves several unknown precursors, formation and evolution pathways and multiple natural and anthropogenic sources. Here a combined gas-particle phase source apportionment is applied to wintertime and summertime data collected in the megacity of Paris in order to investigate SOA origin during both seasons. This was possible by combining the information provided by an aerosol mass spectrometer (AMS and a proton transfer reaction mass spectrometer (PTR-MS. A better constrained apportionment of primary OA (POA sources is also achieved using this methodology, making use of gas-phase tracers. These tracers made possible the discrimination between biogenic and continental/anthropogenic sources of SOA. We found that continental SOA was dominant during both seasons (24–50% of total OA, while contributions from photochemistry-driven SOA (9% of total OA and marine emissions (13% of total OA were also observed during summertime. A semi-volatile nighttime component was also identified (up to 18% of total OA during wintertime. This approach was successfully applied here and implemented in a new source apportionment toolkit.

  10. Electro-scrubbing volatile organic carbons in the air stream with a gas diffusion electrode

    Energy Technology Data Exchange (ETDEWEB)

    Yang Ji, E-mail: yangji@ecust.edu.cn [School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237 (China); School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu Kaichen; Jia Jinping; Cao Limei [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2011-04-15

    It is demonstrated that exposing the VOC air streams to the electro-scrubbing reactor with a gas diffusion electrode leads to an efficient removal of organics. The importance order of the influence factors on the electro-scrubbing reactor performance is: conductivity, voltage and air stream flow-rate. The effective conductivity and high voltages generally are beneficial to the removal process and the air flow-rate is not a significant factor compared with the other two, indicating that the reactor might have a consistently satisfying performance within a wide range of gas volumetric load. The mass transfer of both organics and oxygen in the reactor is estimated by mathematical model, and the calculation determines the concentration boundary conditions for the 2-ethoxyethyl acetate removal: if the 2-ethoxyethyl acetate concentration in the inflow air stream holds C{sub G,i} {<=} 0.7198 % , the removal in the electro-scrubbing reactor is electrochemical reaction controlled; if C{sub G,i} > 0.7198 % , the controlling step will be the oxygen mass transfer from the air to the liquid in the electro-scrubbing reactor. The Apparent Current Efficiency of the electro-scrubbing reactor was also determined using COD data, which is significantly higher than some commercial metal oxide electrodes, showing that the reactor is energy efficient and has the promise for the future scale-up.

  11. Microporous Organic Polymers Based on Hyper-Crosslinked Coal Tar: Preparation and Application for Gas Adsorption.

    Science.gov (United States)

    Gao, Hui; Ding, Lei; Bai, Hua; Li, Lei

    2017-02-08

    Hyper-crosslinked polymers (HCPs) are promising materials for gas capture and storage, but high cost and complicated preparation limit their practical application. In this paper, a new type of HCPs (CTHPs) was synthesized through a one-step mild Friedel-Crafts reaction with low-cost coal tar as the starting material. Chloroform was utilized as both solvent and crosslinker to generate a three-dimensional crosslinked network with abundant micropores. The maximum BET surface area of the prepared CTHPs could reach up to 929 m(2)  g(-1) . Owing to the high affinity between the heteroatoms on the coal-tar building blocks and the CO2 molecules, the adsorption capacity of CTHPs towards CO2 reached up to 14.2 wt % (1.0 bar, 273 K) with a high selectivity (CO2 /N2 =32.3). Furthermore, the obtained CTHPs could adsorb 1.27 wt % H2 at 1.0 bar and 77.3 K, and also showed capacity for the capture of high organic vapors at room temperature. In comparison with other reported porous organic polymers, CTHPs have the advantages of low-cost, easy preparation, and high gas-adsorption performance, making them suitable for mass production and practical use in the future.

  12. Analysis of a gas-liquid film plasma reactor for organic compound oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Kevin [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States); Wang, Huijuan [School of Environmental and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); Locke, Bruce R., E-mail: blocke@fsu.edu [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States)

    2016-11-05

    Highlights: • Non-homogeneous filamentary plasma discharge formed along gas-liquid interface. • Hydrogen peroxide formed near interface favored over organic oxidation from liquid. • Post-plasma Fenton reactions lead to complete utilization of hydrogen peroxide. - Abstract: A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2 g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide.

  13. Greenhouse Gas Emissions from Solid and Liquid Organic Fertilizers Applied to Lettuce.

    Science.gov (United States)

    Toonsiri, Phasita; Del Grosso, Stephen J; Sukor, Arina; Davis, Jessica G

    2016-11-01

    Improper application of nitrogen (N) fertilizer and environmental factors can cause the loss of nitrous oxide (NO) to the environment. Different types of fertilizers with different C/N ratios may have different effects on the environment. The focus of this study was to evaluate the effects of environmental factors and four organic fertilizers (feather meal, blood meal, fish emulsion, and cyano-fertilizer) applied at different rates (0, 28, 56, and 112 kg N ha) on NO emissions and to track CO emissions from a lettuce field ( L.). The study was conducted in 2013 and 2014 and compared preplant-applied solid fertilizers (feather meal and blood meal) and multiple applications of liquid fertilizers (fish emulsion and cyano-fertilizer). Three days a week, NO and CO emissions were measured twice per day in 2013 and once per day in 2014 using a closed-static chamber, and gas samples were analyzed by gas chromatography. Preplant-applied solid fertilizers significantly increased cumulative NO emissions as compared with control, but multiple applications of liquid fertilizers did not. Emission factors for NO ranged from 0 to 0.1% for multiple applications of liquid fertilizers and 0.6 to 11% for preplant-applied solid fertilizers, which could be overestimated due to chamber placement over fertilizer bands. In 2014, solid fertilizers with higher C/N ratios (3.3-3.5) resulted in higher CO emissions than liquid fertilizers (C/N ratio, 0.9-1.5). Therefore, organic farmers should consider the use of multiple applications of liquid fertilizers as a means to reduce soil greenhouse gas emissions while maintaining high yields.

  14. Gas chromatography-mass spectrometry profiles of urinary organic acids in healthy captive cheetahs (Acinonyx jubatus).

    Science.gov (United States)

    Tordiffe, Adrian Stephen Wolferstan; van Reenen, Mari; Reyers, Fred; Mienie, Lodewyk Jacobus

    2017-04-01

    In captivity, cheetahs (Acinonyx jubatus) frequently suffer from several unusual chronic diseases that rarely occur in their free-ranging counterparts. In order to develop a better understanding of their metabolism and health we documented the urine organic acids of 41 apparently healthy captive cheetahs, in an untargeted metabolomic study, using gas chromatography-mass spectrometry. A total of 339 organic acids were detected and annotated. Phenolic compounds, thought to be produced by the anaerobic fermentation of aromatic amino acids in the distal colon, as well as their corresponding glycine conjugates, were present in high concentrations. The most abundant organic acids in the cheetahs' urine were an as yet unidentified compound and a novel cadaverine metabolite, tentatively identified as N(1),N(5)-dimethylpentane-1,5-diamine. Pantothenic acid and citramalic acid concentrations correlated negatively with age, while glutaric acid concentrations correlated positively with age, suggesting possible dysregulation of coenzyme A metabolism in older cheetahs. This study provides a baseline of urine organic acid reference values in captive cheetahs and suggests important avenues for future research in this species. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A Worldwide Assessment of Greenhouse Gas Emissions from Drained Organic Soils

    Directory of Open Access Journals (Sweden)

    Francesco Nicola Tubiello

    2016-04-01

    Full Text Available Despite the importance of organic soils, including peatlands, in the global carbon cycle, detailed information on regional and global emissions is scarce. This is due to the difficulty to map, measure, and assess the complex dynamics of land, soil, and water interactions needed to assess the human-driven degradation of organic soils. We produced a new methodology for the comprehensive assessment of drained organic soils in agriculture and the estimation of the associated greenhouse gas emissions. Results indicated that over 25 million hectares of organic soils were drained worldwide for agriculture use, of which about 60% were in boreal and temperate cool areas, 34% in tropical areas, and 5% in warm temperate areas. Total emissions from the drainage were globally significant, totaling nearly one billion tonnes CO2eq annually. Of this, the CO2 component, about 780 million tonnes, represented more than one-fourth of total net CO2 emissions from agriculture, forestry, and land use. The bulk of these emissions came from a few tropical countries in Southeast Asia, and was linked to land clearing and drainage for crop cultivation. Geospatial data relative to this work were disseminated via the FAO geospatial server GeoNetwork, while the national aggregated statistics were disseminated via the FAOSTAT database.

  16. The gas phase origin of complex organic molecules precursors in prestellar cores

    Science.gov (United States)

    Bacmann, A.; Faure, A.

    2016-05-01

    Complex organic molecules (COMs) have long been observed in the warm regions surrounding nascent protostars. The recent discovery of oxygen-bearing COMs like methyl formate or dimethyl ether in prestellar cores (Bacmann et al. [2]), where gas and dust temperatures rarely exceed 10-15 K, has challenged the previously accepted models according to which COM formation relied on the diffusion of heavy radicals on warm (˜30 K) grains. Following these detections, new questions have arisen: do non-thermal processes play a role in increasing radical mobility or should new gas-phase routes be explored? The radicals involved in the formation of the aforementioned COMs, HCO and CH3O represent intermediate species in the grain-surface synthesis of methanol which proceeds via successive hydrogenations of CO molecules in the ice. We present here observations of methanol and its grain-surface precursors HCO, H2CO, CH3O in a sample of prestellar cores and derive their relative abundances. We find that the relative abundances HCO:H2CO:CH3O:CH3OH are constant across the core sample, close to 10:100:1:100. Our results also show that the amounts of HCO and CH3O are consistent with a gas-phase synthesis of these species from H2CO and CH3OH via radical-neutral or ion-molecule reactions followed by dissociative recombinations. Thus, while grain chemistry is necessary to explain the abundances of the parent volatile CH3OH, and possibly H2CO, the reactive species HCO and CH3O might be daughter molecules directly produced in the gas-phase.

  17. Position for determining gas-phase volatile organic compound concentrations in transuranic waste containers. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, M.J.; Liekhus, K.J. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R. [Benchmark Environmental Corp. (United States)

    1998-06-01

    In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.

  18. Metal organic framework absorbent platforms for removal of co2 and h2s from natural gas

    KAUST Repository

    Belmabkhout, Youssef

    2016-10-13

    Provided herein are metal organic frameworks comprising metal nodes and N-donor organic ligands which have high selectivity and stability in the present of gases and vapors including H2S, H2O, and CO2. Methods include capturing one or more of H2S, H2O, and CO2 from fluid compositions, such as natural gas.

  19. Fuel composition and secondary organic aerosol formation: gas-turbine exhaust and alternative aviation fuels.

    Science.gov (United States)

    Miracolo, Marissa A; Drozd, Greg T; Jathar, Shantanu H; Presto, Albert A; Lipsky, Eric M; Corporan, Edwin; Robinson, Allen L

    2012-08-07

    A series of smog chamber experiments were performed to investigate the effects of fuel composition on secondary particulate matter (PM) formation from dilute exhaust from a T63 gas-turbine engine. Tests were performed at idle and cruise loads with the engine fueled on conventional military jet fuel (JP-8), Fischer-Tropsch synthetic jet fuel (FT), and a 50/50 blend of the two fuels. Emissions were sampled into a portable smog chamber and exposed to sunlight or artificial UV light to initiate photo-oxidation. Similar to previous studies, neat FT fuel and a 50/50 FT/JP-8 blend reduced the primary particulate matter emissions compared to neat JP-8. After only one hour of photo-oxidation at typical atmospheric OH levels, the secondary PM production in dilute exhaust exceeded primary PM emissions, except when operating the engine at high load on FT fuel. Therefore, accounting for secondary PM production should be considered when assessing the contribution of gas-turbine engine emissions to ambient PM levels. FT fuel substantially reduced secondary PM formation in dilute exhaust compared to neat JP-8 at both idle and cruise loads. At idle load, the secondary PM formation was reduced by a factor of 20 with the use of neat FT fuel, and a factor of 2 with the use of the blend fuel. At cruise load, the use of FT fuel resulted in no measured formation of secondary PM. In every experiment, the secondary PM was dominated by organics with minor contributions from sulfate when the engine was operated on JP-8 fuel. At both loads, FT fuel produces less secondary organic aerosol than JP-8 because of differences in the composition of the fuels and the resultant emissions. This work indicates that fuel reformulation may be a viable strategy to reduce the contribution of emissions from combustion systems to secondary organic aerosol production and ultimately ambient PM levels.

  20. Greenhouse gas fluxes induced by tillage and fertilisation in an organic grass-clover-wheat sequence

    Science.gov (United States)

    Krauss, Maike; Ruser, Reiner; Hansen, Sissel; Mäder, Paul; Gattinger, Andreas

    2015-04-01

    Reduced tillage is technically a challenging task in organic arable farming due to the weed competition but also concerning the destruction of grass-clover leys. Regarding its climate impact, there are hardly any data existing. Soil-derived greenhouse gas fluxes were therefore monitored in a long-term field trial in Frick/CH. The trial is arranged in a strip-split-plot design on a heavy clay soil and compares since 2002 conventional tillage (up to 15 cm deep mouldboard ploughing) with reduced tillage (skim plough 5 cm deep and occasional chisel ploughing). In addition, cattle slurry only (SL) is compared with a slurry/manure compost treatment (MC) at a rate of 90 kg N/year. MC plots received one manure compost and two slurry batches, the latter applied with SL the same day but with half the amount. The overall management is in compliance with the EU organic farming regulation. Nitrous oxide and methane fluxes were monitored in a two-year period including a grass-clover ley, its destruction and a subsequent winter wheat crop. We adjusted the closed chamber sampling method developed by Flessa et al. (1995) with eight replicates for each treatment. Gas and soil sampling took place weekly with additional measurements after fertiliser and tillage management. Soil samples were analysed for mineralised nitrogen, dissolved organic carbon and water filled pore space. Flux calculation included linear and non-linear regression calculated with the HMR-Model after Pedersen et al. (2010) and Fuss et al. (unpublished). N2O fluxes calculated with the non-linear model were 10% higher than calculated with the linear model only. First results for the grass-clover period show no significant differences in N2O fluxes neither between reduced tillage and ploughing nor between slurry and manure compost/slurry application. However, ley destruction induced high N2O emissions which will be discussed with the subsequent wheat period.

  1. Thermal and Evolved Gas Analysis of Geologic Samples Containing Organic Materials: Implications for the 2007 Mars Phoenix Scout Mission

    Science.gov (United States)

    Lauer, H. V., Jr.; Ming, Douglas W.; Golden, D. C.; Boynton, W. V.

    2006-01-01

    The Thermal and Evolved Gas Analyzer (TEGA) instrument scheduled to fly onboard the 2007 Mars Phoenix Scout Mission will perform differential scanning calorimetry (DSC) and evolved gas analysis (EGA) of soil samples and ice collected from the surface and subsurface at a northern landing site on Mars. We have been developing a sample characterization data library using a laboratory DSC integrated with a quadrupole mass spectrometer to support the interpretations of TEGA data returned during the mission. The laboratory TEGA test-bed instrument has been modified to operate under conditions similar to TEGA, i.e., reduced pressure (e.g., 100 torr) and reduced carrier gas flow rates. We have previously developed a TEGA data library for a variety of volatile-bearing mineral phases, including Fe-oxyhydroxides, phyllosilicates, carbonates, and sulfates. Here we examine the thermal and evolved gas properties of samples that contain organics. One of the primary objectives of the Phoenix Scout Mission is to search for habitable zones by assessing organic or biologically interesting materials in icy soil. Nitrogen is currently the carrier gas that will be used for TEGA. In this study, we examine two possible modes of detecting organics in geologic samples; i.e., pyrolysis using N2 as the carrier gas and combustion using O2 as the carrier gas.

  2. Relationship between total Non-Methane Hydrocarbons (NMHC) and Speciated NMHCs by Photochemical Assessment Monitoring Station (PAMS)

    Science.gov (United States)

    Chen, S.; Ou Yang, C.; Chang, J.; Wang, J.

    2012-12-01

    Total NMHC observations were made in some of the EPA air quality stations (AQS) across Taiwan, along with measurements of ozone, CO, NOx, SO2 and PM10. This network is also complimented by another eight-station network, called photochemical assessment monitoring stations (PAMS), to provide hourly observations of 56 individual volatile organic compounds (VOCs). In this study, the relationship of the total NMHC and PAMS NMHC observations for the period of 2007-2011 at four sites were cross-examined. It was found that both the hourly mixing ratios and variations of the summed PAMS NMHC values were in excellent agreement with the total NMHC data, with the summed PAMS NMHC observations accounted for at least 80% of the total NMHC observations. However, when looking into the VOC emission database, the PAMS NMHC emissions only contributed 58% of the total NMHC emissions. This then leads to about 30% difference in the traditionally observed NMHCs and estimated emissions. The three-dimensional Eulerian air quality model (PAMS-AQM) was used to simulate both the total NMHC and individual PAMS NMHCs, which showed that the sum of the simulated PAMS NMHCs agreed well with the observed PAMS values. However, the modeled total VOC values were significantly higher than the observed total NMHC values, and such findings were consistent among all four stations. This and the above findings combine to suggest that the customarily labeled "total NMHC" reported by almost all air quality stations are underestimates by about 30%. This underestimate is rather uncertain for two reasons: One, both total NMHC and PAMS speciated NMHC measurements underestimate VOC levels in ambient air. Since both types of measurements use the same method of flame ionization detection, it is less sensitive to oxygen containing VOCs (OVOCs), e.g., aldehydes, esters, ketones, ether, acids, etc. than other VOCs. In contrast, the PAMS measurements only target 56 PAMS NMHCs although more directly, and OVOCs also are

  3. Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

    Directory of Open Access Journals (Sweden)

    D. R. Gentner

    2013-10-01

    Full Text Available Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. Ground site measurements in Bakersfield and aircraft measurements of reactive gas-phase organic compounds were made in this region as part of the CalNex (California Research at the Nexus of Air Quality and Climate Change project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions from these prominent sources that are relatively understudied compared to motor vehicles We also developed a statistical modeling method with the FLEXPART-WRF transport and meteorological model using ground-based data to assess the spatial distribution of emissions in the San Joaquin Valley. We present evidence for large sources of paraffinic hydrocarbons from petroleum extraction/processing operations and oxygenated compounds from dairy (and other cattle operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes that have limited previous in situ measurements or characterization in emissions from petroleum operations. Observed dairy emissions were dominated by ethanol, methanol, and acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well-correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The good agreement of the observed petroleum operations source profile with the measured composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil suggests a fugitive emissions pathway during petroleum extraction, storage, or processing with

  4. Analytical strategies for characterizing organic paint media using gas chromatography/mass spectrometry.

    Science.gov (United States)

    Colombini, Maria Perla; Andreotti, Alessia; Bonaduce, Ilaria; Modugno, Francesca; Ribechini, Erika

    2010-06-15

    Throughout history, artists have experimented with a variety of organic-based natural materials, using them as paint binders, varnishes, and ingredients for mordants in gildings. Artists often use many layers of paint to produce particular effects. How we see a painting is thus the final result of how this complex, highly heterogeneous, multimaterial, and multilayered structure interacts with light. The chemical characterization of the organic substances in paint materials is of great importance for artwork conservation because the organic components of the paint layers are particularly subject to degradation. In addition, understanding the organic content and makeup of paint materials allows us to differentiate between the painting techniques that have been used over history. Applying gas chromatography/mass spectrometry (GC/MS) analysis to microsamples of paint layers is widely recognized as the best approach for identifying organic materials, such as proteins, drying oils, waxes, terpenic resins, and polysaccharide gums. The method provides essential information for reconstructing artistic techniques, assessing the best conditions for long-term preservation, and planning restoration. In this Account, we summarize the more common approaches adopted in the study of the organic components of paint materials. Our progress in developing GC/MS analytical procedures in the field of cultural heritage is presented, focusing on problems that arise from (i) the presence of mixtures of many chemically complex and degraded materials, (ii) the interference of inorganic species, (iii) the small size of the samples, and (iv) the risk of contamination. We outline some critical aspects of the analytical strategy, such as the need to optimize specific wet-chemical sample pretreatments in order to separate the various components, hydrolyze macromolecular analytes, clean-up inorganic ions, and derivatize polar molecules for subsequent GC/MS separation and identification. We also

  5. Evidence for a significant proportion of Secondary Organic Aerosol from isoprene above a maritime tropical forest

    Directory of Open Access Journals (Sweden)

    N. H. Robinson

    2011-02-01

    Full Text Available Isoprene is the most abundant non-methane biogenic volatile organic compound (BVOC, but the processes governing secondary organic aerosol (SOA formation from isoprene oxidation are only beginning to become understood and selective quantification of the atmospheric particulate burden remains difficult. Organic aerosol above a tropical rainforest located in Danum Valley, Borneo, Malaysia, a high isoprene emission region, was studied during Summer 2008 using Aerosol Mass Spectrometry and offline detailed characterisation using comprehensive two dimensional gas chromatography. Observations indicate that a substantial fraction (up to 15% by mass of atmospheric sub-micron organic aerosol was observed as methylfuran (MF after thermal desorption. This observation was associated with the simultaneous measurements of established gas-phase isoprene oxidation products methylvinylketone (MVK and methacrolein (MACR. Observations of MF were also made during experimental chamber oxidation of isoprene. Positive matrix factorisation of the AMS organic mass spectral time series produced a robust factor which accounts for an average of 23% (0.18 μg m−3, reaching as much as 53% (0.50 μg m−3 of the total oraganic loading, identified by (and highly correlated with a strong MF signal. Assuming that this factor is generally representative of isoprene SOA, isoprene derived aerosol plays a significant role in the region. Comparisons with measurements from other studies suggest this type of isoprene SOA plays a role in other isoprene dominated environments, albeit with varying significance.

  6. Synthesis and gas adsorption study of porous metal-organic framework materials

    Science.gov (United States)

    Mu, Bin

    Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) have become the focus of intense study over the past decade due to their potential for advancing a variety of applications including air purification, gas storage, adsorption separations, catalysis, gas sensing, drug delivery, and so on. These materials have some distinct advantages over traditional porous materials such as the well-defined structures, uniform pore sizes, chemically functionalized sorption sites, and potential for postsynthetic modification, etc. Thus, synthesis and adsorption studies of porous MOFs have increased substantially in recent years. Among various prospective applications, air purification is one of the most immediate concerns, which has urgent requirements to improve current nuclear, biological, and chemical (NBC) filters involving commercial and military purposes. Thus, the major goal of this funded project is to search, synthesize, and test these novel hybrid porous materials for adsorptive removal of toxic industrial chemicals (TICs) and chemical warfare agents (CWAs), and to install the benchmark for new-generation NBC filters. The objective of this study is three-fold: (i) Advance our understanding of coordination chemistry by synthesizing novel MOFs and characterizing these porous coordination polymers; (ii) Evaluate porous MOF materials for gasadsorption applications including CO2 capture, CH4 storage, other light gas adsorption and separations, and examine the chemical and physical properties of these solid adsorbents including thermal stability and heat capacity of MOFs; (iii) Evaluate porous MOF materials for next-generation NBC filter media by adsorption breakthrough measurements of TICs on MOFs, and advance our understanding about structureproperty relationships of these novel adsorbents.

  7. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Wencai Zhou

    2015-06-01

    Full Text Available The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs, is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM, the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10−16 m2·s−1, whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.

  8. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks

    Science.gov (United States)

    Zhou, Wencai; Wöll, Christof; Heinke, Lars

    2015-01-01

    The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs), is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM), the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10−16 m2·s−1), whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.

  9. Rapid, automated gas chromatographic detection of organic compounds in ultra-pure water

    Energy Technology Data Exchange (ETDEWEB)

    MOWRY,CURTIS DALE; BLAIR,DIANNA S.; MORRISON,DENNIS J.; REBER,STEPHEN D.; RODACY,PHILIP J.

    2000-02-15

    An automated gas chromatography was used to analyze water samples contaminated with trace (parts-per-billion) concentrations of organic analytes. A custom interface introduced the liquid sample to the chromatography. This was followed by rapid chromatographic analysis. Characteristics of the analysis include response times less than one minute and automated data processing. Analytes were chosen based on their known presence in the recycle water streams of semiconductor manufacturers and their potential to reduce process yield. These include acetone, isopropanol, butyl acetate, ethyl benzene, p-xylene, methyl ethyl ketone and 2-ethoxy ethyl acetate. Detection limits below 20 ppb were demonstrated for all analytes and quantitative analysis with limited speciation was shown for multianalyte mixtures. Results are discussed with respect to the potential for on-line liquid process monitoring by this method.

  10. Gas storage in porous metal-organic frameworks for clean energy applications.

    Science.gov (United States)

    Ma, Shengqian; Zhou, Hong-Cai

    2010-01-07

    Depletion of fossil oil deposits and the escalating threat of global warming have put clean energy research, which includes the search for clean energy carriers such as hydrogen and methane as well as the reduction of carbon dioxide emissions, on the urgent agenda. A significant technical challenge has been recognized as the development of a viable method to efficiently trap hydrogen, methane and carbon dioxide gas molecules in a confined space for various applications. This issue can be addressed by employing highly porous materials as storage media, and porous metal-organic frameworks (MOFs) which have exceptionally high surface areas as well as chemically-tunable structures are playing an unusual role in this respect. In this feature article we provide an overview of the current status of clean energy applications of porous MOFs, including hydrogen storage, methane storage and carbon dioxide capture.

  11. Partially Interpenetrated NbO Topology Metal–Organic Framework Exhibiting Selective Gas Adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Gaurav; Kumar, Sanjay; Pham, Tony; Niu, Zheng; Wojtas, Lukasz; Perman, Jason A.; Chen, Yu-Sheng; Ma, Shengqian

    2017-03-29

    We report on the first partially interpenetrated metal–organic framework (MOF) with NbO topology for its ability to separate methane from carbon dioxide and permanently sequester the greenhouse gas CO2. The MOF, Cu2(pbpta) (H4pbpta = 4,4',4'',4'''-(1,4-phenylenbis(pyridine-4,2-6-triyl))-tetrabenzoic acid), crystallizes in the monoclinic C2/m space group and has a 2537 m2/g Brunauer, Emmett and Teller surface area with an 1.06 cm3/g pore volume. The MOF exhibits selective adsorption of CO2 over CH4 as well as that of C2H6 and C2H4 over CH4. Cu2(pbpta) additionally shows excellent catalytic efficacy for the cycloaddition reaction of CO2 with epoxides to produce industrially important cyclic carbonates using solvent-free conditions.

  12. Gas chromatography-mass spectrometry analysis of various organic extracts ofMerremia borneensisfrom Sabah

    Institute of Scientific and Technical Information of China (English)

    M Amzad Hossain; Muhammad Dawood Shah; Mahyar Sakari

    2011-01-01

    Objective:To analyse the chemical composition of different extracts ofMerremia borneensis (M. borneensis) by gas chromatography-mass spectrometry (GC-MS).Methods: The dried leaves powder was extracted with methanol at room temperature by using Soxhlet extractor. Methanol crude extracts ofM. borneensis were extrastel with hexane, chloroform, ethyl acetate and butanol. Results: Qualitative analyses of various organic crude extracts showed that majority of these are flavonoids, terpeniods, alkaloids and glycosides. Most of the identified compounds by GC-MS are biologically important. Further theM. borneensisleaf possesses certain characteristics that can be ascribed to cultivation on a domestic plantation.Conclusions: The suitable extracts for respective compounds can be chosen on the basis of aboveGC-MS analysis. All the major compounds from different extracts are biologically active molecules. Thus the identification of a good number of compounds from various extractsM. borneensis might have some ecological significance.

  13. Numerical Analysis of Silicon Micromachined Gas Pendulum Tilt Sense Organ Temperature Field

    Institute of Scientific and Technical Information of China (English)

    Linhua Piao; Bin Zhang; Yaojie Lv; Fuxue Zhang

    2006-01-01

    An analysis of the sensitive mechanism of silicon micromachined gas pendulum tilt sense organ is made. Adopting the method of FEA (finite element analysis), the temperature field at two points heat source, when the two-dimensional enclosure was inclined, was obtained by application of the program ANSYS-FLOTRAN CFD and a series of procedures, such as modeling, meshing, loading and equation solving. The numerical results show that in the level state, the temperatures at two points heat source are two points in the same isotherm; however, the temperatures are not the same when the enclosure is inclined. The difference of the temperatures will increase with the augment of the tilt angle, and contrarily it will decrease. That is the characteristic used to sense the transformation of obliquity.

  14. Extended lactations may improve cow health, productivity and reduce greenhouse gas emissions from organic dairy production

    DEFF Research Database (Denmark)

    Lehmann, Jesper Overgård; Mogensen, Lisbeth; Kristensen, Troels

    2014-01-01

    The concept of extended lactation is a break with the tradition of getting one calf per cow per year that should improve cow health, increase productivity and reduce greenhouse gas (GHG) emission per kg milk produced in high-yield organic dairy herds. These effects are achieved through fewer...... calvings per year and hence a production of fewer replacement heifers, which, in combination with fewer days dry per cow per year, will reduce the annual herd requirement for feed. Total herd feed use is a major determinant of GHG emission at farm gate. However, these effects also rely on the assumption...... of an unchanged milk production per feeding day (days lactating plus days dry) when changing from lactations of traditional length to extended lactations. Thus, milk yield per feeding day becomes a primary determinant of the success of using extended lactations at farm level. Cows undergoing an extended lactation...

  15. Complex Organic Molecules Formation in Space Through Gas Phase Reactions: A Theoretical Approach

    Science.gov (United States)

    Redondo, Pilar; Barrientos, Carmen; Largo, Antonio

    2017-02-01

    Chemistry in the interstellar medium (ISM) is capable of producing complex organic molecules (COMs) of great importance to astrobiology. Gas phase and grain surface chemistry almost certainly both contribute to COM formation. Amino acids as building blocks of proteins are some of the most interesting COMs. The simplest one, glycine, has been characterized in meteorites and comets and, its conclusive detection in the ISM seems to be highly plausible. In this work, we analyze the gas phase reaction of glycine and {{{CH}}5}+ to establish the role of this process in the formation of alanine or other COMs in the ISM. Formation of protonated α- and β-alanine in spite of being exothermic processes is not viable under interstellar conditions because the different paths leading to these isomers present net activation energies. Nevertheless, glycine can evolve to protonated 1-imide-2, 2-propanediol, protonated amino acetone, protonated hydroxyacetone, and protonated propionic acid. However, formation of acetic acid and protonated methylamine is also a favorable process and therefore will be a competitive channel with the evolution of glycine to COMs.

  16. Diffusion of methane and other alkanes in metal-organic frameworks for natural gas storage

    Energy Technology Data Exchange (ETDEWEB)

    Borah, B; Zhang, HD; Snurr, RQ

    2015-03-03

    Diffusion of methane, ethane, propane and n-butane was studied within the micropores of several metal organic frameworks (MOFs) of varying topologies, including the MOFs PCN-14, NU-125, NU-1100 and DUT-49. Diffusion coefficients of the pure components, as well as methane/ethane, methane/ propane and methane/butane binary mixtures, were calculated using molecular dynamics simulations to understand the effect of the longer alkanes on uptake of natural gas in MOB. The calculated self diffusion coefficients of all four components are on the order of 10(-8) m(2)/s. The diffusion coefficients of the pure components decrease as a function of chain length in all of the MOFs studied and show different behaviour as a function of loading in different MOB. The self-diffusivities follow the trend DPCN-14 < DNU-125 approximate to DNU-1100 < DDUT-49, which is exactly the reverse order of the densities of the MOFs: PCN-14 > NU-125 approximate to NU-1100 > DUT-49. By comparing the diffusion of pure methane and methane mixtures vvith the higher alkancs, it is observed that the diffusivity of methane is unaffected by the presence of the higher alkanes in the MOFs considered, indicating that the diffusion path of methane is not blocked by the higher alkanes present in natural gas. (C) 2014 Elsevier Ltd. All rights reserved.

  17. Metal-organic framework nanosheets in polymer composite materials for gas separation

    Science.gov (United States)

    Seoane, Beatriz; Miro, Hozanna; Corma, Avelino; Kapteijn, Freek; Llabrés i Xamena, Francesc X.; Gascon, Jorge

    2014-01-01

    Composites incorporating two-dimensional nanostructures within polymeric matrices hold potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic-frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of free standing nanosheets has proven challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometer lateral dimensions and nanometer thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increment in the separation selectivity with pressure. As revealed by tomographic focused-ion-beam scanning-electron-microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared to isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications. PMID:25362353

  18. Springtime depletion of tropospheric ozone, gaseous elemental mercury and non-methane hydrocarbons in the European Arctic, and its relation to atmospheric transport

    Science.gov (United States)

    Eneroth, Kristina; Holmén, Kim; Berg, Torunn; Schmidbauer, Norbert; Solberg, Sverre

    Using a trajectory climatology for the period 1992-2001 we have examined how seasonal changes in transport cause changes in the concentrations of tropospheric ozone (O 3), gaseous elemental mercury (GEM) and non-methane hydrocarbons (NMHCs) observed at the Mt. Zeppelin station, Ny-Ålesund (78.9°N, 11.9°E). During April-June O 3 depletion events were frequently observed in connection with air transport across the Arctic Basin. The O 3 loss was most pronounced in air masses advected close to the surface. This result supports the idea that the O 3 depletion reactions take place in the lowermost part of the atmosphere in the central Arctic Basin. A strong positive correlation between springtime O 3 depletion events and the oxidation of GEM to divalent mercury was found. During air mass advection from Siberia, the Barents Sea and the Norwegian Sea the strongest correlation was observed during April-May, whereas air masses originating from the Canadian Arctic and the central Arctic areas showed the highest O 3-GEM correlation in May-June. We suggest that this 1-month lag could either be due to the position of the marginal ice zone or temperature differences between the northwestern and northeastern air masses. In connection with springtime O 3 depletion events low concentrations of some NMHCs, especially ethane and ethyne, were observed, indicating that both bromine (ethyne oxidant) and chlorine radicals (ethane oxidant) are present in the Arctic atmosphere during spring. In winter, negative correlations between O 3 and NMHCs were found in connection with air transport from Europe and Siberia, which we interpret as O 3 destruction taking place in industrially contaminated plumes.

  19. A volatile organic analyzer for Space Station: Description and evaluation of a gas chromatography/ ion mobility

    Science.gov (United States)

    Limero, Thomas F.; James, John T.

    1994-01-01

    A Volatile Organic Analyzer (VOA) is being developed as an essential component of the Space Station's Environmental Health System (EHS) air quality monitoring strategy to provide warning to the crew and ground personnel if volatile organic compounds exceed established exposure limits. The short duration of most Shuttle flights and the relative simplicity of the contaminant removal mechanism have lessened the concern about crew exposure to air contaminants on the Shuttle. However, the longer missions associated with the Space Station, the complex air revitalization system and the proposed number of experiments have led to a desire for real-time monitoring of the contaminants in the Space Station atmosphere. Achieving the performance requirements established for the VOA within the Space Station resource (e.g., power, weight) allocations led to a novel approach that joined a gas chromatograph (GC) to an ion mobility spectrometer (IMS). The authors of this paper will discuss the rational for selecting the GC/IMS technology as opposed to the more established gas chromatography/mass spectrometry (GC/MS) for the foundation of the VOA. The data presented from preliminary evaluations will demonstrate the versatile capability of the GC/IMS to analyze the major contaminants expected in the Space Station atmosphere. The favorable GC/IMS characteristics illustrated in this paper included excellent sensitivity, dual-mode operation for selective detection, and mobility drift times to distinguish co-eluting GC peaks. Preliminary studies have shown that the GC/IMS technology can meet surpass the performance requirements of the Space Station VOA.

  20. Characterization of non-methane hydrocarbons emitted from Chinese cooking%中式餐饮业油烟中非甲烷碳氢化合物排放特征研究

    Institute of Scientific and Technical Information of China (English)

    张春洋; 马永亮

    2011-01-01

    使用挥发性有机物采样标准方法TO-14/15,选择了北京市5家不同菜系、不同营业规模的餐馆,在其营业时段,连续采集油烟中非甲烷碳氢(NMHCs)样品,使用气相色谱质谱联用仪(GC/MS)进行样品分析.研究了4大类72种NMHCs排放浓度和组分组成特点.不同采样餐馆的NMHCs排放浓度存在差异,与菜系类型、规模、上座率、档次高低均有关系.用基准风量折算后,采样餐馆NMHCs基准排放浓度变化范围为9.13×103~14.2×103μg·m-3.在组分分布上,烷烃、烯烃和芳香烃在采样餐馆NMHCs组分组成中占主%EPA Method TO-14/15 for measurement of toxic organics in air samples was applied to examine non-methane hydrocarbon(NMHC) emissions from 5 Chinese restaurants in Beijing.The 5 restaurants use 4 different cooking styles.A total of 72 components of VOCs were observed.The distinguishing characteristics of NMHC emissions from different restaurants are attributed to their cooking style,business scale,number of customers and restaurant grade.Based on the calibrated baseline ventilation volume,the NMHC concentrations of the examined restaurants were in the range of 9.13×103~14.2×103μg · m-3.Alkanes,alkenes and aromatics were the major NMHC components,which were in the ranges of 28.4%~47.9%,8.9%~58.3% and 10.8%~50.4%,respectively,according to the specified parameters set for the individual restaurant.However,the proportion of chlorohydrocarbons and naphthalene varied significantly,especially that of naphthalene.Based on our sampling results and catering industry data from the Beijing statistical yearbook the total amount of NMHCs emitted from commercial restaurants in Beijing was roughly estimated,to be 10559 tons per year.The data suggest that commercial cooking might be an important source of ozone precursors.

  1. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume IV ? gas phase reactions of organic halogen species

    OpenAIRE

    2007-01-01

    International audience; This article, the fourth in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of organic halogen species, which were last published in 1997, and were updated on the IUPAC website in 2006. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and four appen...

  2. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species

    OpenAIRE

    2006-01-01

    This article, the second in the series, presents kinetic and photochemical data evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of Organic species, which were last published in 1999, and were updated on the IUPAC website in late 2002, and subsequently during the preparation of this article. The article consists of a summary table of the recommended rate coefficients, containing the...

  3. Determining the Main Gas-generation Phase of Marine Organic Matters in Different Occurrence States using the Kinetic Method

    Institute of Scientific and Technical Information of China (English)

    WANG Yunpeng; ZHAO Changyi; WANG Zhaoyun; WANG Hongjun; ZOU Yanrong; LIU Jinzhong; ZHAO Wenzhi; LIU Dehan; LU Jialan

    2008-01-01

    This paper probes the determination of the main gas-generation phase of marine organic mattes using the kinetic method. The main gas-generation phase of marine organic matters was determined by coupling the gas generation yields and rates in geological history computed by the acquired kinetic parameters of typical marine organic matters (reservoir oil, residual bitumen, low-maturity kerogen and residual kerogen) in both China and abroad and maturity by the EasyRo(%) method. Here, the main gas-generation phase was determined as Ro%=1.4%-2.4% for type Ⅰ kerogen, Ro%=1.5-3.0% for low-maturity type Ⅱ kerogen, Ro%=1.4-2.8% for residual kerogen,Ro%=1.5-3.2% for residual bitumen and Ro%=1.6-3.2% for reservoir oil cracking. The influences on the main gas-generation phase from the openness of the simulated system and the "dead line" of natural gas generation are also discussed. The results indicate that the openness of simulation system has a definite influence on computing the main gas-generation phase. The main gas-generation phase of type Ⅱ kerogen is Ro%=1.4-3.1% in an open system, which is earlier than that in a closed system.According to our results, the "dead line" of natural gas generation is determined as Ro=3.5% for type Ⅰ kerogen, Ro=4.4-4.5% for type Ⅱ kerogen and Ro=4.6% for marine oil. Preliminary applications are presented taking the southwestern Tarim Basin as an example.

  4. [Determination of residual organic solvents in flunixin meglumine raw material by headspace gas chromatography].

    Science.gov (United States)

    Hu, Huilian

    2012-01-01

    A method for the determination of five kinds of residual organic solvents in flunixin meglumine raw material was developed by headspace gas chromatography. An HP-FFAP capillary column (30 m x 0.32 mm x 1.0 microm), a flame ionization detector and the external standard method were used for the separation and quantitative analysis. The effects of equilibrium temperature and equilibrium time on the determination of residual organic solvents were investigated. The good results were obtained in the equilibrium temperature of 90 degrees C and equilibrium time of 30 min. The standard curves were linear in the range of 0.40-7.93 mg/L (r = 0.999 8) for ethyl acetate, 7.32-146.48 mg/L (r = 0.999 6) for methanol, 4.53-90.61 mg/L (r = 0.999 9) for isopropanol, 3.62-72.32 mg/L (r = 0.999 8) for ethanol and 2.31-46.24 mg/L (r = 0.999 6) for acetonitrile. The recoveries for the five residual organic solvents were between 95.96% and 100.31% with relative standard deviations (RSDs) (n = 6) of 1.97%-3.28%. The detection limits of ethyl acetate, methanol, isopropanol, ethanol and acetonitrile were 0.08, 0.9, 0.2, 0.4 and 0.3 mg/L, respectively. The proposed method was successfully applied to analyze the residual organic solvents in the real sample of flunixin meglumine raw material. The results showed that only isopropanol and ethanol were found in the sample with the contents of 177.44 microg/g and 69.32 microg/g, respectively. The method is rapid, sensitive and accurate for the content determination of residual solvents in flunixin meglumine raw material.

  5. Formation of secondary organic aerosols from gas-phase emissions of heated cooking oils

    Science.gov (United States)

    Liu, Tengyu; Li, Zijun; Chan, ManNin; Chan, Chak K.

    2017-06-01

    Cooking emissions can potentially contribute to secondary organic aerosol (SOA) but remain poorly understood. In this study, formation of SOA from gas-phase emissions of five heated vegetable oils (i.e., corn, canola, sunflower, peanut and olive oils) was investigated in a potential aerosol mass (PAM) chamber. Experiments were conducted at 19-20 °C and 65-70 % relative humidity (RH). The characterization instruments included a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). The efficiency of SOA production, in ascending order, was peanut oil, olive oil, canola oil, corn oil and sunflower oil. The major SOA precursors from heated cooking oils were related to the content of monounsaturated fat and omega-6 fatty acids in cooking oils. The average production rate of SOA, after aging at an OH exposure of 1. 7 × 1011 molecules cm-3 s, was 1. 35 ± 0. 30 µg min-1, 3 orders of magnitude lower compared with emission rates of fine particulate matter (PM2. 5) from heated cooking oils in previous studies. The mass spectra of cooking SOA highly resemble field-derived COA (cooking-related organic aerosol) in ambient air, with R2 ranging from 0.74 to 0.88. The average carbon oxidation state (OSc) of SOA was -1.51 to -0.81, falling in the range between ambient hydrocarbon-like organic aerosol (HOA) and semi-volatile oxygenated organic aerosol (SV-OOA), indicating that SOA in these experiments was lightly oxidized.

  6. Secondary organic aerosol formation exceeds primary particulate matter emissions for light-duty gasoline vehicles

    Directory of Open Access Journals (Sweden)

    T. D. Gordon

    2013-09-01

    Full Text Available The effects of photochemical aging on emissions from 15 light-duty gasoline vehicles were investigated using a smog chamber to probe the critical link between the tailpipe and ambient atmosphere. The vehicles were recruited from the California in-use fleet; they represent a wide range of model years (1987 to 2011, vehicle types and emission control technologies. Each vehicle was tested on a chassis dynamometer using the unified cycle. Dilute emissions were sampled into a portable smog chamber and then photochemically aged under urban-like conditions. For every vehicle, substantial secondary organic aerosol (SOA formation occurred during cold-start tests, with the emissions from some vehicles generating as much as 6 times the amount of SOA as primary particulate matter after three hours of oxidation inside the chamber at typical atmospheric oxidant levels. Therefore, the contribution of light duty gasoline vehicle exhaust to ambient PM levels is likely dominated by secondary PM production (SOA and nitrate. Emissions from hot-start tests formed about a factor of 3–7 less SOA than cold-start tests. Therefore, catalyst warm-up appears to be an important factor in controlling SOA precursor emissions. The mass of SOA generated by photo-oxidizing exhaust from newer (LEV1 and LEV2 vehicles was only modestly lower (38% than that formed from exhaust emitted by older (pre-LEV vehicles, despite much larger reductions in non-methane organic gas emissions. These data suggest that a complex and non-linear relationship exists between organic gas emissions and SOA formation, which is not surprising since SOA precursors are only one component of the exhaust. Except for the oldest (pre-LEV vehicles, the SOA production could not be fully explained by the measured oxidation of speciated (traditional SOA precursors. Over the time scale of these experiments, the mixture of organic vapors emitted by newer vehicles appear to be more efficient (higher yielding in

  7. Gas-phase products and secondary organic aerosol formation from the ozonolysis and photooxidation of myrcene

    Science.gov (United States)

    Böge, Olaf; Mutzel, Anke; Iinuma, Yoshiteru; Yli-Pirilä, Pasi; Kahnt, Ariane; Joutsensaari, Jorma; Herrmann, Hartmut

    2013-04-01

    Terrestrial vegetation releases a great variety of volatile organic compounds (VOC) into the atmosphere. Monoterpenes, like myrcene, contribute significantly to this global biogenic VOC emission. In the atmosphere, monoterpenes rapidly undergo oxidation reactions by OH radicals (mainly during the daytime), NO3 radicals (mainly during the nighttime) and O3 to form multifunctional oxidation products. The products of these reactions are likely to be of low volatility and hence might lead to secondary organic aerosol (SOA) formation. In the present study, we report results from a series of chamber experiments performed in the LEAK chamber at TROPOS in which the gas-phase products and SOA yields obtained from myrcene O3 reactions with and without an OH radical scavenger as well as from the myrcene OH radical reaction in the presence of NOx have been measured. During the experiments the consumption of myrcene as well as the formation of gas-phase products was monitored using a proton transfer reaction mass spectrometer (PTR-MS). Ozone concentration was measured by an O3 monitor and the mixing ratios of nitrogen oxides were measured by a NOx monitor. Particle size distributions between 3-900 nm were monitored every 11 min using a differential mobility particle sizer (DMPS) system. In addition to the products observed by means of the PTR-MS by their m/z values, an identification of carbonylic compounds by their DNPH derivatives was performed. Beside low molecular mass products the formation of 4-vinyl-4-pentenal with a yield of 55 % in myrcene ozonolysis has been observed. The further oxidation of this major first generation product lead to the formation of two dicarbonylic products with m/z 113 and to SOA formation. The influence of the continuing oxidation of 4-vinyl-4-pentenal on SOA formation will be discussed in detail. The emergence of the gas-phase product hydroxyacetone as direct result of the myrcene ozone reaction will be mooted, because hydroxyacetone seems to

  8. Structures and Gas Storage Performance of Metal-organic Framework Materials at High Pressures

    Science.gov (United States)

    Song, Yang; Hu, Yue; Huang, Yining

    2013-06-01

    Metal Organic Frameworks (MOFs), are crystalline nanoporous materials comprised of small metal clusters connected three-dimensionally by polyfunctional organic ligands. MOFs have been widely studied due to their high porosity, surface area and thermal stability, which make them promising candidates for gas capture and storage. In the MOF family, Zeolitic Imidazolate Frameworks (ZIFs) have attracted much attention because of their promising applications for CO2 storage. In contrast to the extensive studies under ambient conditions, most ZIFs have only been studied under pressure in a very limited range. It is known that pressure can provide an effective driving force to achieve structural modification which includes changes in pore size, opening and geometry, channel shape and internal surface area. Subsequently, these pressure-induced changes will affect the sorption selectivity, capacity and access to the binding sites of the porous materials. Here, we report the first in situ high-pressure investigation of several ZIFs by FTIR spectroscopy. We observed rich pressure-induced transformations upon compression in different pressure ranges. Furthermore, the reversibilities of these transformations upon decompression were also examined. Finally, the performance of CO2 storage of selected ZIFs at high pressures will be addressed. Our observation and analyses contribute to the understanding of chemical and mechanical properties of ZIFs under high-pressure conditions and provide new insight into their storage applications.

  9. Intermolecular interactions governing the partition between particulate and gas phases for typical organic pollutants

    Institute of Scientific and Technical Information of China (English)

    YU HaiYing; QIAO XianLiang; YANG Ping; DING GuangHui; CHEN JingWen

    2007-01-01

    The partition coefficients between particulate and gas phases (Kp) for organic pollutants are of great importance to characterize the behavior of organic pollutants in atmosphere, and are basic data needed by ecological risk assessment. Partial least squares (PLS) regression with 16 theoretical molecular structural descriptors was used to develop polyparameter linear free energy relationship (LFER) model for Kp of 18 aliphatic hydrocarbons, 21 polycyclic aromatic hydrocarbons (PAHs), 16 polychlorinated biphenyls (PCBs) and 13 polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs). The obtained model has a good predictive ability and robustness, which can be used for estimating Kp of chemicals with similar structures. Intermolecular dispersive interactions play a leading role in governing Kp, followed by charge-transfer interactions and hindrance effects of molecular size. The respective models developed for different group compounds imply that the action mechanism is similar, and dipole-dipole and dipole-induced dipole interactions play a minor role in governing Kp of n-alkanes, PCBs and PCDD/Fs.

  10. Interactions of Gas-Phase Nitric/Nitrous Acids and Primary Organic Aerosol in the Atmosphere of Houston, TX

    Science.gov (United States)

    Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Whitlow, S. I.; Lefer, B. L.; Flynn, J.; Rappenglück, B.

    2007-12-01

    Concentrations of aerosol and gas-phase pollutants were measured on the roof of an 18-story building during the Texas Air Quality Study II Radical and Aerosol Measurement Project (TRAMP) from August 15 through September 28, 2006. Aerosol measurements included size-resolved, non-refractory mass concentrations of ammonium, nitrate, sulfate, chloride, and organic aerosol in submicron particles using an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS). Particulate water-soluble organic carbon (PWSOC) was quantified using a mist chamber/total organic carbon analysis system. Concentration data for gas-phase pollutants included those for nitric acid (HNO3), nitrous acid (HONO), and hydrochloric acid (HCl) collected using a mist chamber/ion chromatographic technique, oxides of nitrogen (NOx) collected using a chemiluminescent method, and carbon monoxide (CO) collected using an infrared gas correlation wheel instrument. Coincident increases in nitrate and organic aerosol mass concentrations were observed on many occasions throughout the measurement campaign, most frequently during the morning rush hour. Based on the lack of organic aerosol processing (defined by the ratio of m/z = 44/57 in the Q-AMS spectra), strong correlation with NOx and CO, and a lack of significant increase in PWSOC concentration, the spikes in organic aerosol were likely associated with primary organic aerosol (POA). During these events, gas-phase HNO3 concentration decreases were observed simultaneously with increases in gas-phase HONO concentrations. These data likely indicate uptake of HNO3 and subsequent heterogeneous conversion to HONO involving POA. Preliminary calculations show that HNO3 partitioning could account for the majority of the observed HONO and aerosol nitrate concentrations during these events. Q-AMS chloride and HCl data also indicate uptake of chloride by particles during these events. This phenomenon was also observed during the night, but these nocturnal events were less

  11. Greenhouse gas budgets for grasslands on peatlands and other organic soils

    Science.gov (United States)

    Tiemeyer, Bärbel; Albiac Borraz, Elisa; Augustin, Jürgen; Bechtold, Michel; Beetz, Sascha; Beyer, Colja; Eickenscheidt, Tim; Drösler, Matthias; Förster, Christoph; Freibauer, Annette; Giebels, Michael; Glatzel, Stephan; Heinichen, Jan; Hoffmann, Mathias; Höper, Heinrich; Leiber-Sauheitl, Katharina; Rosskopf, Niko; Zeitz, Jutta

    2014-05-01

    Drained peatlands are hotspots of greenhouse gas (GHG) emissions. Grassland is the major land use type for peatlands in Germany and other European countries, but strongly varies in its intensity regarding the groundwater level and the agricultural management. These parameters are known to influence the GHG emissions. Furthermore, little is known about the emissions from grasslands on soils which are rich in organic matter, but cannot be classified as peatlands (e.g. Histic Gleysols). We synthesized 116 annual GHG budgets for 46 different sites in 11 German peatlands. Carbon dioxide (net ecosystem exchange and ecosystem respiration), nitrous oxide and methane fluxes were measured with transparent and opaque manual chambers. Land management ranged from very intensive use with up to five cuts per year to re-wetted grasslands with only one cut late in the year. Besides the GHG fluxes, biomass yield, fertilisation, groundwater level, climatic data, vegetation composition and soil properties were measured. Overall, we found a large variability of the total GHG budget ranging from small uptakes (- 6 t CO2- equivalents/(ha yr)) to very high losses (74 t CO2-equivalents/(ha yr)). At all sites, the GHG budget was dominated by carbon dioxide, generally followed by biomass export. Surprisingly, there was no difference between the average GHG budget of the peatlands and of the other organic soils. Thus, the GHG budget did not depend on soil organic carbon concentration or stock. Generally, the groundwater table depth was the best predictor for GHG emissions at each individual peatland, but a poor overall predictor. For all sites, the GHG budget was explained best by the average nitrogen stock above the mean groundwater level.

  12. Anatomy of a cluster IDP. Part 2: Noble gas abundances, trace element geochemistry, isotopic abundances, and trace organic chemistry of several fragments from L2008#5

    Science.gov (United States)

    Thomas, K. L.; Clemett, S. J.; Flynn, G. J.; Keller, L. P.; Mckay, David S.; Messenger, S.; Nier, A. O.; Schlutter, D. J.; Sutton, S. R.; Walker, R. M.

    1994-01-01

    The topics discussed include the following: noble gas content and release temperatures; trace element abundances; heating summary of cluster fragments; isotopic measurements; and trace organic chemistry.

  13. Gas adsorption and storage in metal-organic framework MOF-177.

    Science.gov (United States)

    Li, Yingwei; Yang, Ralph T

    2007-12-18

    Gas adsorption experiments have been carried out on a zinc benzenetribenzoate metal-organic framework material, MOF-177. Hydrogen adsorption on MOF-177 at 298 K and 10 MPa gives an adsorption capacity of approximately 0.62 wt %, which is among the highest hydrogen storage capacities reported in porous materials at ambient temperatures. The heats of adsorption for H2 on MOF-177 were -11.3 to -5.8 kJ/mol. By adding a H2 dissociating catalyst and using our bridge building technique to build carbon bridges for hydrogen spillover, the hydrogen adsorption capacity in MOF-177 was enhanced by a factor of approximately 2.5, to 1.5 wt % at 298 K and 10 MPa, and the adsorption was reversible. N2 and O2 adsorption measurements showed that O2 was adsorbed more favorably than N2 on MOF-177 with a selectivity of approximately 1.8 at 1 atm and 298 K, which makes MOF-177 a promising candidate for air separation. The isotherm was linear for O2 while being concave for N2. Water vapor adsorption studies indicated that MOF-177 adsorbed up to approximately 10 wt % H2O at 298 K. The framework structure of MOF-177 was not stable upon H2O adsorption, which decomposed after exposure to ambient air in 3 days. All the results suggested that MOF-177 could be a potentially promising material for gas separation and storage applications at ambient temperature (under dry conditions or with predrying).

  14. Determination of Organic Pollutants in Small Samples of Groundwaters by Liquid-Liquid Extraction and Capillary Gas Chromatography

    DEFF Research Database (Denmark)

    Harrison, I.; Leader, R.U.; Higgo, J.J.W.;

    1994-01-01

    A method is presented for the determination of 22 organic compounds in polluted groundwaters. The method includes liquid-liquid extraction of the base/neutral organics from small, alkaline groundwater samples, followed by derivatisation and liquid-liquid extraction of phenolic compounds after...... neutralisation. The extracts were analysed by capillary gas chromatography. Dual detection by flame Ionisation and electron capture was used to reduce analysis time....

  15. Earthworms change the quantity and composition of dissolved organic carbon and reduce greenhouse gas emissions during composting

    NARCIS (Netherlands)

    Nigussie, Abebe; Bruun, Sander; Neergaard, de Andreas; Kuijper, Thomas

    2017-01-01

    Dissolved organic carbon (DOC) has recently been proposed as an indicator of compost stability. We assessed the earthworms' effect on DOC content and composition during composting, and linked compost stability to greenhouse gas emissions and feeding ratio. Earthworms reduced total DOC content,

  16. Chemical Composition of Gas Phase and Secondary Organic Aerosol from Aromatic Precursors Produced in a Smog Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sax, M. [ETH Zuerich and PSI (Switzerland); Kalberer, M. [ETH Zuerich (Switzerland); Zenobi, R. [ETH Zuerich (Switzerland); Paulsen, D.; Baltensperger, U.

    2004-03-01

    Reaction products formed during photooxidation of aromatic compounds contribute to secondary organic aerosol (SOA) mass. In this study we performed experiments with 1,3,5-trimethylbenzene (135TMB) in the PSI smog chamber to study the formation and composition of SOA. We used different techniques to analyze the aerosol and the gas phase. (author)

  17. Earthworms change the quantity and composition of dissolved organic carbon and reduce greenhouse gas emissions during composting

    NARCIS (Netherlands)

    Nigussie, Abebe; Bruun, Sander; Neergaard, de Andreas; Kuijper, Thomas

    2017-01-01

    Dissolved organic carbon (DOC) has recently been proposed as an indicator of compost stability. We assessed the earthworms' effect on DOC content and composition during composting, and linked compost stability to greenhouse gas emissions and feeding ratio. Earthworms reduced total DOC content, in

  18. Gas transport in metal organic framework–polyetherimide mixed matrix membranes: The role of the polyetherimide backbone structure

    NARCIS (Netherlands)

    Hegde, Maruti; Shahid, S.; Norder, Ben; Dingemans, Theo J.; Nijmeijer, Dorothea C.

    2015-01-01

    We report on how the morphology of the polymer matrix, i.e. amorphous vs. semi-crystalline, affects the gas transport properties in a series of mixed matrix membranes (MMMs) using Cu3(BTC)2 as the metal organic framework (MOF) filler. The aim of our work is to demonstrate how incorporation of

  19. Pyrolysis-gas chromatography/mass spectrometry of soil organic matter extracted from a Brazilian mangrove and Spanish salt marshes

    NARCIS (Netherlands)

    Perobelli Ferreira, F.; Buurman, P.; Macias, F.; Otero, X.L.; Boluda, R.

    2009-01-01

    The soil organic matter (SOM) extracted under different vegetation types from a Brazilian mangrove (Pai Matos Island, São Paulo State) and from three Spanish salt marshes (Betanzos Ría and Corrubedo Natural Parks, Galícia, and the Albufera Natural Park, Valencia) was investigated by pyrolysis-gas ch

  20. ANALYSIS OF TRACE-LEVEL ORGANIC COMBUSTION PROCESS EMISSIONS USING NOVEL MULTIDIMENSIONAL GAS CHROMATOGRAPHY-MASS SPECTROMETRY PROCEDURES

    Science.gov (United States)

    The paper discusses the analysis of trace-level organic combustion process emissions using novel multidimensional gas chromatography-mass spectrometry (MDGC-MS) procedures. It outlines the application of the technique through the analyses of various incinerator effluent and produ...

  1. The influence of aerosol size and organic carbon content on gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs)

    Energy Technology Data Exchange (ETDEWEB)

    Offenberg, J.H.; Baker, J.E. [University of Maryland, Solomons, MD (United States). Chesapeake Biological Lab.

    2002-07-01

    Concentrations of polycyclic aromatic hydrocarbons (Paths) were measured on size segregated airborne particulate matter and in the gas phase during 12h periods in urban Chicago and over southern Lake Michigan during July 1994 and January 1995 as part of the atmospheric exchange over lakes and oceans (AEOLOS) project. In the 19 paired gas phase and size segregated particle samples, partition coefficients of polycyclic aromatic hydrocarbons are well correlated with the sub-cooled liquid vapor pressure, (p{sub l}{sup 0}) within an aerosol size class. However, partition coefficients differ systematically according to particle size and aerosol organic carbon content. Approximately 68% of the observed variability in measured PAH partition coefficients is explained by a three dimensional multiple linear regression that includes vapor pressure of the compound of interest, aerosol particle aerodynamic equivalent diameter, aerosol organic carbon content and interaction terms. However, addition of both particle size and the fraction organic carbon terms, while statistically significant, appear to be of minimal importance in improving our ability to model gas/particle partitioning in the atmosphere. The influence of either particle size or fraction organic carbon is nearly as large as the calculated random error in partition coefficients, and suggests that an important factor in predicting gas/particle partitioning has not yet been incorporated in the current model. [author].

  2. Gas transport in metal organic framework–polyetherimide mixed matrix membranes: The role of the polyetherimide backbone structure

    NARCIS (Netherlands)

    Hegde, Maruti; Shahid, Salman; Norder, Ben; Dingemans, Theo J.; Nijmeijer, Kitty

    2015-01-01

    We report on how the morphology of the polymer matrix, i.e. amorphous vs. semi-crystalline, affects the gas transport properties in a series of mixed matrix membranes (MMMs) using Cu3(BTC)2 as the metal organic framework (MOF) filler. The aim of our work is to demonstrate how incorporation of Cu3(BT

  3. Volatile organic compounds at oil and natural gas production well pads in Colorado and Texas using passive samplers

    Science.gov (United States)

    A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Methods 325A/B variant for monitoring volatile organic compounds (VOCs) near two oil and natural gas (ONG) production well pads in the Texas Barnett Shale formation and Colorado Denver&nd...

  4. Organic compounds present in the natural Amazonian aerosol: Characterization by gas chromatography-mass spectrometry

    Science.gov (United States)

    Graham, Bim; Guyon, Pascal; Taylor, Philip E.; Artaxo, Paulo; Maenhaut, Willy; Glovsky, M. Michael; Flagan, Richard C.; Andreae, Meinrat O.

    2003-12-01

    As part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)-Cooperative LBA Airborne Regional Experiment (CLAIRE) 2001 campaign in July 2001, separate day and nighttime aerosol samples were collected at a ground-based site in Amazonia, Brazil, in order to examine the composition and temporal variability of the natural "background" aerosol. We used a high-volume sampler to separate the aerosol into fine (aerodynamic diameter, AD 2.5 μm) size fractions and quantified a range of organic compounds in methanolic extracts of the samples by a gas chromatographic-mass spectrometric technique. The carbon fraction of the compounds could account for an average of 7% of the organic carbon (OC) in both the fine and coarse aerosol fractions. We observed the highest concentrations of sugars, sugar alcohols, and fatty acids in the coarse aerosol samples, which suggests that these compounds are associated with primary biological aerosol particles (PBAP) observed in the forest atmosphere. Of these, trehalose, mannitol, arabitol, and the fatty acids were found to be more prevalent at night, coinciding with a nocturnal increase in PBAP in the 2-10 μm size range (predominantly yeasts and other small fungal spores). In contrast, glucose, fructose, and sucrose showed persistently higher daytime concentrations, coinciding with a daytime increase in large fungal spores, fern spores, pollen grains, and, to a lesser extent, plant fragments (generally >20 μm in diameter), probably driven by lowered relative humidity and enhanced wind speeds/convective activity during the day. For the fine aerosol samples a series of dicarboxylic and hydroxyacids were detected with persistently higher daytime concentrations, suggesting that photochemical production of a secondary organic aerosol from biogenic volatile organic compounds may have made a significant contribution to the fine aerosol. Anhydrosugars (levoglucosan, mannosan, galactosan), which are specific tracers for biomass

  5. Detecting Organic Compounds in Martian Soil Analogues Using Gas Chromatography Mass Spectrometry

    Science.gov (United States)

    Glavin, D. P.; Buch, A.; Mahaffy, P. R.

    2004-01-01

    One of the primary objectives of the 1976 Viking missions was to determine whether organic compounds, possibly of biological origin, were present in the Martian surface soils. The Viking gas chromatography mass spectrometry (GCMS) instruments found no evidence for any organic compounds of Martian origin above a few parts per billion in the upper 10 cm of surface soil [l], suggesting the absence of a widely distributed Martian biota. However, Benner et d. have suggested that significant amounts of non-volatile organic compounds, possibly including oxidation products of bioorganic molecules (e.g. carboxylic acids) would not have been detected by the Viking GCMS [2]. Moreover, other key organic compounds important to biology, such as amino acids and nucleobases, would also likely have been missed by the Viking GCMS as these compounds require chemical derivatization to be stable in a GC column [3]. Recent pyrolysis experiments with a Mars soil analogue that had been innoculated with Escherichia coli bacteria have shown that amino acid decomposition products (amines) and nucleobases are among the most abundant products generated after pyrolysis of the bacterial cells [4,5]. At the part per billion level (Viking GCMS detection limit), these pyrolysis products generated from several million bacterial cells per gram of Martian soil would not have been detected by the Viking GCMS instruments [4]. Analytical protocols are under development for upcoming in situ lander opportunities to target several important biological compounds including amino acids and nucleobases. For example, extraction and chemical derivatization techniques [3] are being adapted for space flight use to transform reactive or fragile molecules that would not have been detected by the Viking GCMS instruments, into species that are sufficiently volatile to be detected by GCMS. Recent experiments carried out at NASA Goddard have shown that using this derivatization technique all of the targeted compounds

  6. Detecting Organic Compounds in Martian Soil Analogues Using Gas Chromatography Mass Spectrometry

    Science.gov (United States)

    Glavin, D. P.; Buch, A.; Mahaffy, P. R.

    2004-01-01

    One of the primary objectives of the 1976 Viking missions was to determine whether organic compounds, possibly of biological origin, were present in the Martian surface soils. The Viking gas chromatography mass spectrometry (GCMS) instruments found no evidence for any organic compounds of Martian origin above a few parts per billion in the upper 10 cm of surface soil [l], suggesting the absence of a widely distributed Martian biota. However, Benner et d. have suggested that significant amounts of non-volatile organic compounds, possibly including oxidation products of bioorganic molecules (e.g. carboxylic acids) would not have been detected by the Viking GCMS [2]. Moreover, other key organic compounds important to biology, such as amino acids and nucleobases, would also likely have been missed by the Viking GCMS as these compounds require chemical derivatization to be stable in a GC column [3]. Recent pyrolysis experiments with a Mars soil analogue that had been innoculated with Escherichia coli bacteria have shown that amino acid decomposition products (amines) and nucleobases are among the most abundant products generated after pyrolysis of the bacterial cells [4,5]. At the part per billion level (Viking GCMS detection limit), these pyrolysis products generated from several million bacterial cells per gram of Martian soil would not have been detected by the Viking GCMS instruments [4]. Analytical protocols are under development for upcoming in situ lander opportunities to target several important biological compounds including amino acids and nucleobases. For example, extraction and chemical derivatization techniques [3] are being adapted for space flight use to transform reactive or fragile molecules that would not have been detected by the Viking GCMS instruments, into species that are sufficiently volatile to be detected by GCMS. Recent experiments carried out at NASA Goddard have shown that using this derivatization technique all of the targeted compounds

  7. Effect of total gas velocity on the growth of ZnO films by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Junjie [School of Advanced Materials Engineering and Research Center for Advanced Materials Development, Engineering College, Chonbuk National University, Chonju 561-756 (Korea, Republic of); Yao Ran [Department of physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Liu Cihui [Department of physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Lee, In-Hwan [School of Advanced Materials Engineering and Research Center for Advanced Materials Development, Engineering College, Chonbuk National University, Chonju 561-756 (Korea, Republic of); Zhu Lala [Department of physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ju, Jin-woo [School of Advanced Materials Engineering and Research Center for Advanced Materials Development, Engineering College, Chonbuk National University, Chonju 561-756 (Korea, Republic of); Baek, Jong Hyeob [Center of Technology Strategy Development, Korea Photonics Technology Institute, Gwangju 500-210 (Korea, Republic of); Lin Bixia [Department of physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Fu Zhuxi [Department of physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)]. E-mail: fuzx@ustc.edu.cn

    2006-08-30

    ZnO films were grown on Si (100) substrates at low pressure in a vertical metal-organic chemical vapor deposition reactor with different total gas velocity. The structure and photoluminescence property of the undoped ZnO films grown with different flow rates of N{sub 2} eluting gas were investigated. The structure quality was improved as the N{sub 2} flow rate increased. In addition, when the flow rate of N{sub 2} eluting gas was higher than 1.4 slm, a new luminescence peak which was attributed to the N-related defect was detected at room temperature, besides the other two peaks near the band gap, which were due to radiation of the free exciton and the electron from the donor level to the valence band respectively, also appeared at low flow rate of N{sub 2} eluting gas.

  8. Online derivatization for hourly measurements of gas- and particle-phase semi-volatile oxygenated organic compounds by thermal desorption aerosol gas chromatography (SV-TAG)

    Science.gov (United States)

    Isaacman, G.; Kreisberg, N. M.; Yee, L. D.; Worton, D. R.; Chan, A. W. H.; Moss, J. A.; Hering, S. V.; Goldstein, A. H.

    2014-12-01

    Laboratory oxidation studies have identified a large number of oxygenated organic compounds that can be used as tracers to understand sources and oxidation chemistry of atmospheric particulate matter. Quantification of these compounds in ambient environments has traditionally relied on low-time-resolution collection of filter samples followed by offline sample treatment with a derivatizing agent to allow analysis by gas chromatography of otherwise non-elutable organic chemicals with hydroxyl groups. We present here an automated in situ instrument for the measurement of highly polar organic semi-volatile and low-volatility compounds in both the gas- and particle-phase with hourly quantification of mass concentrations and gas-particle partitioning. The dual-cell semi-volatile thermal desorption aerosol gas chromatograph (SV-TAG) with derivatization collects particle-only and combined particle-plus-vapor samples on two parallel sampling cells that are analyzed in series by thermal desorption into helium saturated with derivatizing agent. Introduction of MSTFA (N-methyl-N-(trimethylsilyl)trifluoroacetamide), a silylating agent, yields complete derivatization of all tested compounds, including alkanoic acids, polyols, diacids, sugars, and multifunctional compounds. In laboratory tests, derivatization is found to be highly reproducible (regularly injected internal standard is used to correct for variability in detector response, consumption of the derivatization agent, desorption efficiency, and transfer losses. Error in quantification from instrument fluctuations is found to be less than 10% for hydrocarbons and less than 15% for all oxygenates for which a functionally similar internal standard is available, with an uncertainty of 20-25% in measurements of particle fraction. After internal standard corrections, calibration curves are found to be linear for all compounds over the span of 1 month, with comparable response on both of the parallel sampling cells.

  9. Plasmonic nanoantenna array with single-chip integrated metal-organic framework for infrared absorption gas sensing (Conference Presentation)

    Science.gov (United States)

    Chong, Xinyuan; Kim, Ki-Joong; Li, Erwen; Zhang, Yujing; Ohodnicki, Paul R.; Chang, Chih-Hung; Wang, Alan X.

    2017-03-01

    Surface-enhanced infrared absorption (SEIRA) is a spectroscopic technique used to identify molecular fingerprints by resonant detection of infrared vibrational modes through coupling with the plasmonic modes of metallic nanostructures. Many reported works have demonstrated its capability to enhance the infrared absorption of solid or liquid samples. However, this technique has not been successfully applied to gas sensing yet due to the short light-matter interaction length and intrinsically weak absorption of gas compared to solid or liquid materials. Usually, IR gas sensing is conducted in a gas cell with a long absorption path. In the paper, we propose an integrated photonic device to expand the application of SEIRA to gas sensing by combining metal-organic framework (MOF) ZIF-8 (zeolitic imidazole framework) with plasmonic nanoantenna array. The device consists of an Au nanopatch array on sapphire substrate and is covered by a thin layer of MOF material. The MOF thin film, which is a new class of highly nanoporous material, serves as a gas absorber to selectively adsorb and concentrate CO2 from ambient environment into the thin layer, which has a high spatial overlap with the high intensity optical field of the plasmonic nanopatch antenna array. Namely, we can effectively increase the gas molecule concentration at the hot-spots for the SEIRA device. The experimentally demonstrated peak IR enhancement factor of the device for carbon dioxide sensing is over 1,100 times.

  10. Snowflake-Shaped ZnO Nanostructures-Based Gas Sensor for Sensitive Detection of Volatile Organic Compounds

    Directory of Open Access Journals (Sweden)

    Tianli Han

    2017-01-01

    Full Text Available Volatile organic compounds (VOCs have been considered severe risks to human health. Gas sensors for the sensitive detection of VOCs are highly required. However, the preparation of gas-sensing materials with a high gas diffusion performance remains a great challenge. Here, through a simple hydrothermal method accompanied with a subsequent thermal treatment, a special porous snowflake-shaped ZnO nanostructure was presented for sensitive detection of VOCs including diethyl ether, methylbenzene, and ethanol. The fabricated gas sensors exhibit a good sensing performance including high responses to VOCs and a short response/recovery time. The responses of the ZnO-based gas sensor to 100 ppm ethanol, methylbenzene, and diethyl ether are about 27, 21, and 11, respectively, while the response times to diethyl ether and methylbenzene are less than 10 seconds. The gas adsorption-desorption kinetics is also investigated, which shows that the gas-sensing behaviors to different target gases are remarkably different, making it possible for target recognition in practical applications.

  11. High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages.

    Science.gov (United States)

    Baek, Seung Bin; Moon, Dohyun; Graf, Robert; Cho, Woo Jong; Park, Sung Woo; Yoon, Tae-Ung; Cho, Seung Joo; Hwang, In-Chul; Bae, Youn-Sang; Spiess, Hans W; Lee, Hee Cheon; Kim, Kwang S

    2015-11-17

    Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO2 sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H3BTB) and N,N-dimethylformamide (DMF) and by π-π stacking between the H3BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO2 at high temperatures due to thermally activated molecular gating, and the weakly confined CO2 molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO2 sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO2 with the organic framework and dynamic motion of CO2 in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO2 (a series of transient opening/closing of compartments enabling CO2 molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use.

  12. Functionalized Metal-organic Frameworks for Applications in Gas Storage and Catalysis

    Science.gov (United States)

    Dau, Phuong Viet

    Metal-organic frameworks (MOFs) are 3-dimensional (3D) inorganic-organic hybrid materials. Due to their hybrid structures, MOFs have been increasingly become attractive materials for energy related applications. In recent years, many methods have been investigated and utilized to functionalize MOFs with a variety of chemical groups to enhance its properties. Among these methods, prefunctionalization and postsynthetic modification methods (PSM) have been proven to be versatile and accessible pathways to incorporate functional groups into MOFs. In this dissertation, the use of prefunctionalization and PSM methods to decorate MOFs with functionalities, and an overview of functionalized MOFs for applications in gas storage and catalysis will be highlighted and investigated. In the first part of the dissertation, a series of free phenylpyridine functionalized MOFs are synthesized and characterized. These MOFs are further decorated with Ir(I) and Rh(I) via cyclometalation reactions using PSM method. Amazingly, a selective PSM on an interpenetrated MOF is unprecedentedly observed. The selective outcome of the PSM is the result of the spatial difference between of chemically modifiable sites within the interpenetrated framework. In the second haft of this dissertation, Ir(I)phenylpyrdine functionalized MOFs are showed to be effective, stable, and reusable heterogeneous catalysts for allylic N-alkylation of amines. Furthermore, the use of prefunctionalization and PSM methods are utilized for the rational synthesis of a bifunctional, site-isolated MOF that has both organocatalytic -NH2 and organometallic Ir(I)phenylpyridine. The bifunctional MOF is further investigated as a tandem catalyst for one-pot condensation and alkylation reactions. Lastly, the synthesis of the first pair of isomeric MOFs is realized via prefunctionalization and PSM methods. More importantly, these cubic isoreticular MOFs with disordered ordered phenyl amide substituents displayed drastic differences

  13. Suspended trapping gas chromatography I fourier transform mass spectrometry for analysis of complex organic mixtures.

    Science.gov (United States)

    Hogan, J D; Laude, D A

    1990-11-01

    The superior sensitivity , dynamic range, and mass measurement accuracy of suspended trapping pulse sequences for gas chromatography combined with Fourier transform mass spectrometry (GC/FTMS) separations of complex organic mixtures is demonstrated. By combining intense ionization conditions with a suspended trapping event prior to detection the working range of the trapped ion cell is increased by 10(3) . Improved detection limits are shown for the GC/FTMS separation of a peppermint oil, with the suspended trapping total ion chromatogram yielding 28 peaks, compared with 15 with a conventional trapping pulse sequence. A fivefold to fifteenfold improvement in signal-to-noise for suspended trapping measurements is also demonstrated with comparison spectra from separations of an unleaded gasoline sample. Suspended trapping spectra show little mass discrimination when an external ion reservoir is used, and chromatographic peak heights differ from conventional spectra by less than 30% if the initial ion population is within the space charge limit of the cell. Finally, average wide band mass measurement errors for components differing in concentration by several orders of magnitude are improved by a factor of 6 to 20 with suspended trapping compared with conventional trapping . For example, average errors of 8.7 ppm are obtained for a suspended trapping GC/FTMS separation of peppermint oil from a single calibration table in which the analysis is perfonned in the absence of calibrant.

  14. Analysis of a gas-liquid film plasma reactor for organic compound oxidation.

    Science.gov (United States)

    Hsieh, Kevin; Wang, Huijuan; Locke, Bruce R

    2016-11-01

    A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide.

  15. Determination of volatile organic compounds in river water by solid phase extraction and gas chromatography

    Institute of Scientific and Technical Information of China (English)

    M. A. Mottaleb; M. Z. Abedin; M. S. Islam

    2004-01-01

    A simple, rapid, and reproducible method is described employing solid-phase extraction(SPE) using dichloromethane followed by gas chromatography(GC) with flame ionization detection(FID) for determination of volatile organic compound(VOC) from the Buriganga River water of Bangladesh. The method was applied to detect the benzene, toluene, ethylbenzene, xylene and cumene(BTEXC) in the sample collected from the surface or 15 cm depth of water. Two-hundred ml of n-hexane-pretreated and filtered water samples were applied directly to a C18 SPE column. BTEXC were extracted with dichloromethane and average concentrations were obtained as 0.104 to 0.372 (g/ml. The highest concentration of benzene was found as 0.372 (g/ml with a relative standard deviation(RSD) of 6.2%, and cumene was not detected. Factors influencing SPE e.g., adsorbent types, sample load volume, eluting solvent, headspace and temperatures, were investigated. A cartridge containing a C18 adsorbent and using dichloromethane gave better performance for extraction of BTEXC from water.Average recoveries exceeding 90% could be achieved for cumene at 4℃with a 2.7%RSD

  16. Integrated gas chromatography for ultrafast analysis of volatile organic compounds in air.

    Science.gov (United States)

    Zhang, Yanggang; Wu, Dapeng; Yan, Xiaohui; Ding, Kun; Guan, Yafeng

    2016-07-01

    An integrated instrumentation of a cryogenic microtrap-thermal desorption-low thermal mass (LTM) fast gas chromatographic (GC) system had been designed and evaluated for the ultrafast enrichment and separation of trace amounts of highly volatile organic compounds (VOCs) in air. The LTM fast GC column was wrapped uniformly on outer surface of a thin metal heating cylinder of 65mm O.D. and 0.5mm in thickness. Both of microtrap and LTM column could be rapidly cooled by liquid CO2 down to -35°C, and heated by resistive heating. A 10m×100µm i.d. micro-bore capillary column was used in the LTM GC column module to provide a high separation speed. Key operational parameters, including adsorbent mass, trapping temperature, thermal desorption temperature and injection time were optimized. Under the optimized condition, the 39 species of TO-14 VOCs were well resolved and quantified in less than 3min. The detection limits were in the range of 8 ppt-0.22 ppb at sampling volume of 50mL and trapping temperature of -10°C. The average peak width was 0.9s, and the peak capacity of ~150 (at unit resolution) was obtained. The applicability of the setup was evaluated by analyzing three real environmental samples, where some typical VOCs at sub ppb level were detected.

  17. The rate of photocatalytic oxidation of aromatic volatile organic compounds in the gas-phase

    Science.gov (United States)

    Boulamanti, Aikaterini K.; Korologos, Christos A.; Philippopoulos, Constantine J.

    In the present study, the gas-solid heterogeneous photocatalytic oxidation (PCO) of six aromatic species of volatile organic compounds (VOCs), benzene, toluene, ethylbenzene, m-, o- and p-xylene over illuminated titania was carried out at ambient temperature in a continuous stirring-tank reactor. Initial VOC concentrations were in the low parts per million (ppm) range. Maximum conversions were over 90% for all compounds except from benzene, ethylbenzene and o-xylene, while the residence time varied from 50 to 210 s. Intermediates were detected only in the case of the xylenes, but catalyst deactivation occurred for all six compounds. The PCO kinetics were well fit by a Langmuir-Hinshelwood (L-H) model for monomolecular surface reaction and it was proved that the reaction rate is related to both constants. The rate constants ranged from 0.147 ppm s -1 g cat-1 for benzene to 1.067 ppm s -1 g cat-1 for m-xylene, while the adsorption constants from 0.424 ppm -1 for ethylbenzene to 0.69 ppm -1 for toluene. The molecular structure of the compounds was found to play an important role in the reaction. Finally the efficiency of the procedure in the case of a mixture of these aromatic substances was tested.

  18. In situ Analysis of Organic Compounds on Mars using Chemical Derivatization and Gas Chromatography Mass Spectrometry

    Science.gov (United States)

    Glavin, D. P.; Buch, A.; Cabane, M.; Coll, P.; Navarro-Gonzalez, R.; Mahaffy, P. R.

    2005-01-01

    One of the core science objectives of NASA's 2009 Mars Science Laboratory (MSL) mission is to determine the past or present habitability of Mars. The search for key organic compounds relevant to terrestrial life will be an important part of that assessment. We have developed a protocol for the analysis of amino acids and carboxylic acids in Mars analogue materials using gas chromatography mass spectrometry (GCMS). As shown, a variety of carboxylic acids were readily identified in soil collected from the Atacama Desert in Chile at part-per-billion levels by GCMS after extraction and chemical derivatization using the reagent N,N-tert.-butyl (dimethylsilyl) trifluoroacetamide (MTBSTFA). Several derivatized amino acids including glycine and alanine were also detected by GCMS in the Atacama soil at lower concentrations (chromatogram not shown). Lacking derivatization capability, the Viking pyrolysis GCMS instruments could not have detected amino acids and carboxylic acids, since these non-volatile compounds require chemical transformation into volatile species that are stable in a GC column. We are currently optimizing the chemical extraction and derivatization technique for in situ GCMS analysis on Mars. Laboratory results of analyses of Atacama Desert samples and other Mars analogue materials using this protocol will be presented.

  19. Achieving a Good Life Time in a Vertical-Organic-Diode Gas Sensor

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Dai

    2014-09-01

    Full Text Available In this study, we investigate the keys to obtain a sensitive ammonia sensor with high air stability by using a low-cost polythiophene diode with a vertical channel and a porous top electrode. Poly(3-hexylthiophene (P3HT and air-stable poly(5,5'-bis(3-dodecyl-2-thienyl-2,2'-bithiophene (PQT-12 are both evaluated as the active sensing layer. Two-dimensional current simulation reveals that the proposed device exhibits numerous connected vertical nanometer junctions (VNJ. Due to the de-doping reaction between ammonia molecules and the bulk current flowing through the vertical channel, both PQT-12 and P3HT VNJ-diodes exhibit detection limits of 50-ppb ammonia. The P3HT VNJ-diode, however, becomes unstable after being stored in air for two days. On the contrary, the PQT-12 VNJ-diode keeps an almost unchanged response to 50-ppb ammonia after being stored in air for 25 days. The improved storage lifetime of an organic-semiconductor-based gas sensor in air is successfully demonstrated.

  20. A Review on Breathing Behaviors of Metal-Organic-Frameworks (MOFs) for Gas Adsorption

    Science.gov (United States)

    Alhamami, Mays; Doan, Huu; Cheng, Chil-Hung

    2014-01-01

    Metal-organic frameworks (MOFs) are a new class of microporous materials that possess framework flexibility, large surface areas, “tailor-made” framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses. PMID:28788614

  1. Cryogen free automated gas chromatography for the measurement of ambient volatile organic compounds.

    Science.gov (United States)

    Wang, J L; Chen, W L; Lin, Y H; Tsai, C H

    2000-10-27

    An automated gas chromatographic system was constructed for measuring ambient volatile organic compounds (VOCs). Preconcentration of the VOCs was performed by using two separated sorbent traps of different combinations with each designated for either low or high boiling VOCs. Both traps and their associated valve systems were integrated as a complete system sharing a common sample inlet. Precise temperature controls for desorption relied on the use of a process controller with proportional-integral-derivative algorithm to throttle the current supply. No additional cryo-focusing stage prior to the column was needed owing to the flash heating capability for desorption. Other than the cryogen free preconcentration and focusing, the separation of VOCs of large volatility difference was also performed without cryogen. The system employed an Al2O3/KCl porous-layer open tubular column for separating C3-C7 compounds; and a DB-1 column for C6-C12. This automated GC system has been deployed in a Taiwan Environmental Protection Agency urban air quality monitoring station of Taiwan for continuous measuring C3-C7 ozone precursors. Excellent correlation between the car exhaust type of compounds measured by our GC system and carbon monoxide measured by a non-dispersive infrared spectrometer was observed, suggesting the automated GC system was robust and reliable.

  2. Optimization of Low-Temperature Exhaust Gas Waste Heat Fueled Organic Rankine Cycle

    Institute of Scientific and Technical Information of China (English)

    WANGHui—tao; WANGHua; ZHANGZhu—ming

    2012-01-01

    Low temperature exhaust gases carrying large amount of waste heat are released by steel-making process and many other industries, Organic Rankine Cycles (ORCs) are proven to be the most promising technology to re- cover the low-temperature waste heat, thereby to get more financial benefits for these industries. The exergy analysis of ORC units driven by low-temperature exhaust gas waste heat and charged with dry and isentropic fluid was per- formed, and an intuitive approach with simple impressions was developed to calculate the performances of the ORC unit. Parameter optimization was conducted with turbine inlet temperature simplified as the variable and exergy effi- ciency or power output as the objective function by means of Penalty Function and Golden Section Searching algo- rithm based on the formulation of the optimization problem. The power generated by the optimized ORC unit can be nearly as twice as that generated by a non-optimized ORC unit. In addition, cycle parametric analysis was performed to examine the effects of thermodynamic parameters on the cycle performances such as thermal efficiency and exergy efficiency. It is proven that performance of ORC unit is mainly affected by the thermodynamic property of working fluid, the waste heat temperature, the pinch point temperature of the evaporator, the specific heat capacity of the heat carrier and the turbine inlet temperature under a given environment temperature.

  3. Reactions of metal cluster anions with inorganic and organic molecules in the gas phase.

    Science.gov (United States)

    Zhao, Yan-Xia; Liu, Qing-Yu; Zhang, Mei-Qi; He, Sheng-Gui

    2016-07-28

    The study of gas phase ion-molecule reactions by state-of-the-art mass spectrometric experiments in conjunction with quantum chemistry calculations offers an opportunity to clarify the elementary steps and mechanistic details of bond activation and conversion processes. In the past few decades, a considerable number of publications have been devoted to the ion-molecule reactions of metal clusters, the experimentally and theoretically tractable models for the active phase of condensed phase systems. The focus of this perspective concerns progress on activation and transformation of important inorganic and organic molecules by negatively charged metal clusters. The metal cluster anions cover bare metal clusters as well as ligated systems with oxygen, carbon, and nitrogen, among others. The following important issues have been summarized and discussed: (i) dependence of chemical reactivity and selectivity on cluster structures and sizes, metals and metal oxidation states, odd-even electron numbers, etc. and (ii) effects of doping, ligation, and pre-adsorption on the reactivity of metal clusters toward rather inert molecules.

  4. A Review on Breathing Behaviors of Metal-Organic-Frameworks (MOFs for Gas Adsorption

    Directory of Open Access Journals (Sweden)

    Mays Alhamami

    2014-04-01

    Full Text Available Metal-organic frameworks (MOFs are a new class of microporous materials that possess framework flexibility, large surface areas, “tailor-made” framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses.

  5. Application of capillary gas chromatography mass spectrometry/computer techniques to synoptic survey of organic material in bed sediment

    Science.gov (United States)

    Steinheimer, T.R.; Pereira, W.E.; Johnson, S.M.

    1981-01-01

    A bed sediment sample taken from an area impacted by heavy industrial activity was analyzed for organic compounds of environmental significance. Extraction was effected on a Soxhlet apparatus using a freeze-dried sample. The Soxhlet extract was fractionated by silica gel micro-column adsorption chromatography. Separation and identification of the organic compounds was accomplished by capillary gas chromatography/mass spectrometry techniques. More than 50 compounds were identified; these include saturated hydrocarbons, olefins, aromatic hydrocarbons, alkylated polycyclic aromatic hydrocarbons, and oxygenated compounds such as aldehydes and ketones. The role of bed sediments as a source or sink for organic pollutants is discussed. ?? 1981.

  6. Methods for calculation of engineering parameters for gas separation. [vapor pressure and solubility of gases in organic liquids

    Science.gov (United States)

    Lawson, D. D.

    1979-01-01

    A group additivity method is generated which allows estimation, from the structural formulas alone, of the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. Using these two parameters and appropriate thermodynamic relations, the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids are predicted. It is also possible to use the data to evaluate organic and some inorganic liquids for use in gas separation stages or liquids as heat exchange fluids in prospective thermochemical cycles for hydrogen production.

  7. Towards the future french organization of the natural gas industry; Vers la future organisation gaziere francaise

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    In the framework of the new directive on the internal gas market of 1998, the government proposed a discussion by the presentation of this white book, providing information and questions. This book proposes seven main chapters: the gas industry activity and the directive on the internal gas market; the gas actors, the key numbers and the juridical context in France; define and strengthen the natural gas public utility; useful actions for each gas facilities (transport, distribution, storage and retailers); the realization of progresses for the consumer; the operating of an efficiency control; actions to develop the gas operators in the world. The text of the 98/30/CE directive is also provided. (A.L.B.)

  8. New global fire emission estimates and evaluation of volatile organic compounds

    Science.gov (United States)

    C. Wiedinmyer; L. K. Emmons; S. K. Akagi; R. J. Yokelson; J. J. Orlando; J. A. Al-Saadi; A. J. Soja

    2010-01-01

    A daily, high-resolution, global fire emissions model has been built to estimate emissions from open burning for air quality modeling applications: The Fire INventory from NCAR (FINN version 1). The model framework uses daily fire detections from the MODIS instruments and updated emission factors, specifically for speciated non-methane organic compounds (NMOC). Global...

  9. Observations and analysis of organic aerosol evolution in some prescribed fire smoke plumes

    Science.gov (United States)

    A. A. May; T. Lee; G. R. McMeeking; S. Akagi; A. P. Sullivan; S. Urbanski; R. J. Yokelson; S. M. Kreidenweis

    2015-01-01

    Open biomass burning is a significant source of primary air pollutants such as particulate matter (PM) and non-methane organic gases (NMOG). However, the physical and chemical atmospheric processing of these emissions during transport is poorly understood. Atmospheric transformations of biomass burning emissions have been investigated in environmental chambers, but...

  10. A highly selective and self-powered gas sensor via organic surface functionalization of p-Si/n-ZnO diodes.

    Science.gov (United States)

    Hoffmann, Martin W G; Mayrhofer, Leonhard; Casals, Olga; Caccamo, Lorenzo; Hernandez-Ramirez, Francisco; Lilienkamp, Gerhard; Daum, Winfried; Moseler, Michael; Waag, Andreas; Shen, Hao; Prades, J Daniel

    2014-12-17

    Selectivity and low power consumption are major challenges in the development of sophisticated gas sensor devices. A sensor system is presented that unifies selective sensor-gas interactions and energy-harvesting properties, using defined organic-inorganic hybrid materials. Simulations of chemical-binding interactions and the consequent electronic surface modulation give more insight into the complex sensing mechanism of selective gas detection.

  11. Evaluation of gas-particle partitioning in a regional air quality model for organic pollutants

    Science.gov (United States)

    Efstathiou, Christos I.; Matejovičová, Jana; Bieser, Johannes; Lammel, Gerhard

    2016-12-01

    Persistent organic pollutants (POPs) are of considerable concern due to their well-recognized toxicity and their potential to bioaccumulate and engage in long-range transport. These compounds are semi-volatile and, therefore, create a partition between vapour and condensed phases in the atmosphere, while both phases can undergo chemical reactions. This work describes the extension of the Community Multiscale Air Quality (CMAQ) modelling system to POPs with a focus on establishing an adaptable framework that accounts for gaseous chemistry, heterogeneous reactions, and gas-particle partitioning (GPP). The effect of GPP is assessed by implementing a set of independent parameterizations within the CMAQ aerosol module, including the Junge-Pankow (JP) adsorption model, the Harner-Bidleman (HB) organic matter (OM) absorption model, and the dual Dachs-Eisenreich (DE) black carbon (BC) adsorption and OM absorption model. Use of these descriptors in a modified version of CMAQ for benzo[a]pyrene (BaP) results in different fate and transport patterns as demonstrated by regional-scale simulations performed for a European domain during 2006. The dual DE model predicted 24.1 % higher average domain concentrations compared to the HB model, which was in turn predicting 119.2 % higher levels compared to the baseline JP model. Evaluation with measurements from the European Monitoring and Evaluation Programme (EMEP) reveals the capability of the more extensive DE model to better capture the ambient levels and seasonal behaviour of BaP. It is found that the heterogeneous reaction of BaP with O3 may decrease its atmospheric lifetime by 25.2 % (domain and annual average) and near-ground concentrations by 18.8 %. Marginally better model performance was found for one of the six EMEP stations (Košetice) when heterogeneous BaP reactivity was included. Further analysis shows that, for the rest of the EMEP locations, the model continues to underestimate BaP levels, an observation that can be

  12. Thermodynamic and design considerations of organic Rankine cycles in combined application with a solar thermal gas turbine

    Science.gov (United States)

    Braun, R.; Kusterer, K.; Sugimoto, T.; Tanimura, K.; Bohn, D.

    2013-12-01

    Concentrated Solar Power (CSP) technologies are considered to provide a significant contribution for the electric power production in the future. Different kinds of technologies are presently in operation or under development, e.g. parabolic troughs, central receivers, solar dish systems and Fresnel reflectors. This paper takes the focus on central receiver technologies, where the solar radiation is concentrated by a field of heliostats in a receiver on the top of a tall tower. To get this CSP technology ready for the future, the system costs have to reduce significantly. The main cost driver in such kind of CSP technologies are the huge amount of heliostats. To reduce the amount of heliostats, and so the investment costs, the efficiency of the energy conversion cycle becomes an important issue. An increase in the cycle efficiency results in a decrease of the solar heliostat field and thus, in a significant cost reduction. The paper presents the results of a thermodynamic model of an Organic Rankine Cycle (ORC) for combined cycle application together with a solar thermal gas turbine. The gas turbine cycle is modeled with an additional intercooler and recuperator and is based on a typical industrial gas turbine in the 2 MW class. The gas turbine has a two stage radial compressor and a three stage axial turbine. The compressed air is preheated within a solar receiver to 950°C before entering the combustor. A hybrid operation of the gas turbine is considered. In order to achieve a further increase of the overall efficiency, the combined operation of the gas turbine and an Organic Rankine Cycle is considered. Therefore an ORC has been set up, which is thermally connected to the gas turbine cycle at two positions. The ORC can be coupled to the solar-thermal gas turbine cycle at the intercooler and after the recuperator. Thus, waste heat from different cycle positions can be transferred to the ORC for additional production of electricity. Within this investigation

  13. Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

    Directory of Open Access Journals (Sweden)

    P. Veres

    2010-06-01

    Full Text Available We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs. The Mobile Organic Carbon Calibration System (MOCCS combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC conversion on a palladium surface to CO2 in the presence of oxygen, and the subsequent CO2 measurement. MOCCS was validated using three different comparisons: (1 TOC of high accuracy methane standards compared well to expected concentrations (3% relative error, (2 a gas-phase benzene standard was generated using a permeation source and measured by TOC and gas chromatography mass spectrometry (GC-MS with excellent agreement (<4% relative difference, and (3 total carbon measurement of 4 known gas phase mixtures were performed and compared to a calculated carbon content to agreement within the stated uncertainties of the standards. Measurements from laboratory biomass burning experiments of formic acid by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS and formaldehyde by proton transfer reaction-mass spectrometry (PTR-MS, both calibrated using MOCCS, were compared to open path Fourier transform infrared spectroscopy (OP-FTIR to validate the MOCCS calibration and were found to compare well (R2 of 0.91 and 0.99, respectively.

  14. Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

    Directory of Open Access Journals (Sweden)

    P. Veres

    2010-01-01

    Full Text Available We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs. The Mobile Organic Carbon Calibration System (MOCCS combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC conversion on a palladium surface to CO2 in the presence of oxygen, and the subsequent CO2 measurement. MOCCS was validated using three different comparisons: (1 TOC of high accuracy methane standards compared well to expected concentrations (3% relative error, (2 a gas-phase benzene standard was generated using a permeation source and measured by TOC and gas chromatography mass spectrometry (GC-MS with excellent agreement (<4% relative difference, and (3 total carbon measurement of 4 known gas phase mixtures were performed and compared to a calculated carbon content to agreement within the stated uncertainties of the standards. Measurements from laboratory biomass burning experiments of formic acid by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS and formaldehyde by proton transfer reaction-mass spectrometry (PTR-MS, both calibrated using MOCCS, were compared to open path Fourier transform infrared spectroscopy (OP-FTIR to validate the MOCCS calibration and were found to compare well (R2 of 0.91 and 0.99 respectively.

  15. Molecular interactions in metal organic frameworks for optimized gas separation, storage and sensing applications

    Science.gov (United States)

    Nijem, Nour

    Hydrogen storage and CO2 capture are two of the most challenging problems for the development of renewable energy sources and the reduction of CO2 emission. Hydrogen storage aims at storing a high volumetric density of hydrogen at room temperature. Fundamental studies exploring molecular hydrogen interactions in storage materials are therefore important to foster further development of materials. Metal-organic Frameworks (MOFs) are promising candidates for hydrogen storage and gas separation because their high surface area, porosity and structural tailorability all contribute to selective high hydrogen and CO2 physisorption at specific sites in the structures. This work explores the incorporation of hydrogen, CO2 and hydrocarbons into various MOFs using infrared (IR) and Raman spectroscopy to characterize their interaction. IR spectroscopy can distinguish possible H2 binding sites based on the perturbation of the initially IR inactive internal H2 stretch mode. Comparative IR measurements are performed on MOFs with both saturated metal centers (e.g., M(bdc)(ted)0.5) and unsaturated metal centers (e.g., MOF-74-M with M=Zn, Mg and Ni) by varying the ligand and/or the metal center. We combine room-temperature and high-pressure with low-temperature (20--100K) measurements and use theoretical van der Waals density functional (vdW-DF) calculations to derive quantitative information from the vibrational band shifts and dipole moment strengths. In addition to H2, CO2 and hydrocarbon adsorption and selectivity in a flexible MOF system using Raman and IR spectroscopy are explored. The CO2 specific interaction with the framework and the specific connectivity of the metal to the ligands is found to be the main reason for this MOFs flexibility leading to its large CO2 selectivity, and a novel "gate opening" phenomenon. The unexpected gate opening behavior in this flexible framework upon different hydrocarbon adsorption is studied to uncover effects of specific hydrogen bonding

  16. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume IV – gas phase reactions of organic halogen species

    Directory of Open Access Journals (Sweden)

    R. Atkinson

    2008-08-01

    Full Text Available This article, the fourth in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of organic halogen species, which were last published in 1997, and were updated on the IUPAC website in 2006/07. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and four appendices containing the data sheets, which provide information upon which the recommendations are made.

  17. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species

    Directory of Open Access Journals (Sweden)

    R. Atkinson

    2006-01-01

    Full Text Available This article, the second in the series, presents kinetic and photochemical data evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of Organic species, which were last published in 1999, and were updated on the IUPAC website in late 2002, and subsequently during the preparation of this article. The article consists of a summary table of the recommended rate coefficients, containing the recommended kinetic parameters for the evaluated reactions, and eight appendices containing the data sheets, which provide information upon which the recommendations are made.

  18. Removal of volatile to semi-volatile organic contaminants from water using hollow fiber membrane contactors and catalytic destruction of the contaminants in the gas phase

    OpenAIRE

    Tarafder, Shamsul Abedin

    2007-01-01

    Abstract Chlorinated organic compounds and ether compounds are frequently found in groundwater and efficient treatment options are needed. In this study, the efficient transferal of the compounds from the water phase to the gas phase was studied followed by the catalytic treatment of the gas phase. For the removal of the organic contaminants from water, a microporous polypropylene hollow fiber membrane (HFM) module was operated under low strip gas flow to water flow ratios (_< 5:1). Rem...

  19. On-line derivatization for hourly measurements of gas- and particle-phase Semi-Volatile oxygenated organic compounds by Thermal desorption Aerosol Gas chromatography (SV-TAG

    Directory of Open Access Journals (Sweden)

    G. Isaacman

    2014-07-01

    Full Text Available Laboratory oxidation studies have identified a large number of oxygenated organic compounds that can be used as tracers to understand sources and oxidation chemistry of atmospheric particulate matter. Quantification of these compounds in ambient environments has traditionally relied on low time-resolution collection of filter samples followed by offline sample treatment with a derivatizing agent to allow analysis by gas chromatography of otherwise non-elutable organic chemicals with hydroxyl groups. We present here an automated in situ instrument for the measurement of highly polar organic semi-volatile and low-volatility compounds in both the gas- and particle-phase with hourly time-resolution. The dual-cell Semi-Volatile Thermal desorption Aerosol Gas chromatograph (SV-TAG with derivatization collects particle-only and combined particle-plus-vapor samples on two parallel sampling cells that are analyzed in series by thermal desorption into helium saturated with derivatizing agent. Introduction of MSTFA, a silylating agent, yields complete derivatization of all tested compounds, including alkanoic acids, polyols, diacids, sugars, and multifunctional compounds. In laboratory tests, derivatization is found to be highly reproducible (< 3% variability. During field deployment, a regularly injected internal standard is used to correct for variability in detector response, derivatization efficiency, desorption efficiency, and transfer efficiency. Error in quantification from instrument fluctuations is found to be less than 10% for hydrocarbons and less than 15% for all oxygenates for which a functionally similar internal standard is available. After internal standard corrections, calibration curves are found to be linear for all compounds over the span of one month with comparable response on both of the parallel sampling cells.

  20. On-line derivatization for hourly measurements of gas- and particle-phase Semi-Volatile oxygenated organic compounds by Thermal desorption Aerosol Gas chromatography (SV-TAG)

    Science.gov (United States)

    Isaacman, G.; Kreisberg, N. M.; Yee, L. D.; Worton, D. R.; Chan, A. W. H.; Moss, J. A.; Hering, S. V.; Goldstein, A. H.

    2014-07-01

    Laboratory oxidation studies have identified a large number of oxygenated organic compounds that can be used as tracers to understand sources and oxidation chemistry of atmospheric particulate matter. Quantification of these compounds in ambient environments has traditionally relied on low time-resolution collection of filter samples followed by offline sample treatment with a derivatizing agent to allow analysis by gas chromatography of otherwise non-elutable organic chemicals with hydroxyl groups. We present here an automated in situ instrument for the measurement of highly polar organic semi-volatile and low-volatility compounds in both the gas- and particle-phase with hourly time-resolution. The dual-cell Semi-Volatile Thermal desorption Aerosol Gas chromatograph (SV-TAG) with derivatization collects particle-only and combined particle-plus-vapor samples on two parallel sampling cells that are analyzed in series by thermal desorption into helium saturated with derivatizing agent. Introduction of MSTFA, a silylating agent, yields complete derivatization of all tested compounds, including alkanoic acids, polyols, diacids, sugars, and multifunctional compounds. In laboratory tests, derivatization is found to be highly reproducible (regularly injected internal standard is used to correct for variability in detector response, derivatization efficiency, desorption efficiency, and transfer efficiency. Error in quantification from instrument fluctuations is found to be less than 10% for hydrocarbons and less than 15% for all oxygenates for which a functionally similar internal standard is available. After internal standard corrections, calibration curves are found to be linear for all compounds over the span of one month with comparable response on both of the parallel sampling cells.

  1. Adsorption and reaction of trace gas-phase organic compounds on atmospheric water film surfaces: a critical review.

    Science.gov (United States)

    Donaldson, D J; Valsaraj, Kalliat T

    2010-02-01

    The air-water interface in atmospheric water films of aerosols and hydrometeors (fog, mist, ice, rain, and snow) presents an important surface for the adsorption and reaction of many organic trace gases and gaseous reactive oxidants (hydroxyl radical (OH(.)), ozone (O(3)), singlet oxygen (O(2)((1)Delta(g))), nitrate radicals (NO(3)(.)), and peroxy radicals (RO(2)(.)). Knowledge of the air-water interface partition constant of hydrophobic organic species is necessary for elucidating the significance of the interface in atmospheric fate and transport. Various methods of assessing both experimental and theoretical values of the thermodynamic partition constant and adsorption isotherm are described in this review. Further, the reactivity of trace gases with gas-phase oxidants (ozone and singlet oxygen) at the interface is summarized. Oxidation products are likely to be more water-soluble and precursors for secondary organic aerosols in hydrometeors. Estimation of characteristic times shows that heterogeneous photooxidation in water films can compete effectively with homogeneous gas-phase reactions for molecules in the atmosphere. This provides further support to the existing thesis that reactions of organic compounds at the air-water interface should be considered in gas-phase tropospheric chemistry.

  2. Gas adsorption properties of highly porous metal-organic frameworks containing functionalized naphthalene dicarboxylate linkers.

    Science.gov (United States)

    Sim, Jaeung; Yim, Haneul; Ko, Nakeun; Choi, Sang Beom; Oh, Youjin; Park, Hye Jeong; Park, SangYoun; Kim, Jaheon

    2014-12-28

    Three functionalized metal-organic frameworks (MOFs), MOF-205-NH2, MOF-205-NO2, and MOF-205-OBn, formulated as Zn4O(BTB)4/3(L), where BTB is benzene-1,3,5-tribenzoate and L is 1-aminonaphthalene-3,7-dicarboxylate (NDC-NH2), 1-nitronaphthalene-3,7-dicarboxylate (NDC-NO2) or 1,5-dibenzyloxy-2,6-naphthalenedicarboxylate (NDC-(OBn)2), were synthesized and their gas (H2, CO2, or CH4) adsorption properties were compared to those of the un-functionalized, parent MOF-205. Ordered structural models for MOF-205 and its derivatives were built based on the crystal structures and were subsequently used for predicting porosity properties. Although the Brunauer-Emmett-Teller (BET) surface areas of the three MOF-205 derivatives were reduced (MOF-205, 4460; MOF-205-NH2, 4330; MOF-205-NO2, 3980; MOF-205-OBn, 3470 m(2) g(-1)), all three derivatives were shown to have enhanced H2 adsorption capacities at 77 K and CO2 uptakes at 253, 273, and 298 K respectively at 1 bar in comparison with MOF-205. The results indicate the following trend in H2 adsorption: MOF-205 MOF-205-NO2 MOF-205-NH2 MOF-205-OBn. MOF-205-OBn showed good ideal adsorbed solution theory (IAST) selectivity values of 6.5 for CO2/N2 (15/85 in v/v) and 2.7 for CO2/CH4 (50/50 in v/v) at 298 K. Despite the large reduction (-22%) in the surface area, MOF-205-OBn displayed comparable total volumetric CO2 (at 48 bar) and CH4 (at 35 bar) storage capacities with those of MOF-205 at 298 K: MOF-205-OBn, 305 (CO2) and 112 (CH4) cm(3) cm(-3), and for MOF-205, 307 (CO2) and 120 (CH4) cm(3) cm(-3), respectively.

  3. Role of organic amendment application on greenhouse gas emission from soil.

    Science.gov (United States)

    Thangarajan, Ramya; Bolan, Nanthi S; Tian, Guanglong; Naidu, Ravi; Kunhikrishnan, Anitha

    2013-11-01

    Globally, substantial quantities of organic amendments (OAs) such as plant residues (3.8×10(9) Mg/yr), biosolids (10×10(7) Mg/yr), and animal manures (7×10(9) Mg/yr) are produced. Recycling these OAs in agriculture possesses several advantages such as improving plant growth, yield, soil carbon content, and microbial biomass and activity. Nevertheless, OA applications hold some disadvantages such as nutrient eutrophication and greenhouse gas (GHG) emission. Agriculture sector plays a vital role in GHG emission (carbon dioxide- CO2, methane- CH4, and nitrous oxide- N2O). Though CH4 and N2O are emitted in less quantity than CO2, they are 21 and 310 times more powerful in global warming potential, respectively. Although there have been reviews on the role of mineral fertilizer application on GHG emission, there has been no comprehensive review on the effect of OA application on GHG emission in agricultural soils. The review starts with the quantification of various OAs used in agriculture that include manures, biosolids, and crop residues along with their role in improving soil health. Then, it discusses four major OA induced-GHG emission processes (i.e., priming effect, methanogenesis, nitrification, and denitrification) by highlighting the impact of OA application on GHG emission from soil. For example, globally 10×10(7) Mg biosolids are produced annually which can result in the potential emission of 530 Gg of CH4 and 60 Gg of N2O. The article then aims to highlight the soil, climatic, and OA factors affecting OA induced-GHG emission and the management practices to mitigate the emission. This review emphasizes the future research needs in relation to nitrogen and carbon dynamics in soil to broaden the use of OAs in agriculture to maintain soil health with minimum impact on GHG emission from agriculture. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Role of organic amendment application on greenhouse gas emission from soil

    Energy Technology Data Exchange (ETDEWEB)

    Thangarajan, Ramya, E-mail: thary008@mymail.unisa.edu.au [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide, SA 5095 (Australia); Bolan, Nanthi S. [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide, SA 5095 (Australia); Tian, Guanglong [Environmental Monitoring and Research Division, Monitoring and Research Dep., Metropolitan Water Reclamation District of Greater Chicago, 6001, Pershing Road, Cicero, IL 60804 (United States); Naidu, Ravi [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide, SA 5095 (Australia); Kunhikrishnan, Anitha [Chemical Safety Division, Department of Agro-Food Safety, National Academy of Agricultural Science,10 Suwon-si, Gyeonggi-do (Korea, Republic of)

    2013-11-01

    Globally, substantial quantities of organic amendments (OAs) such as plant residues (3.8 × 10{sup 9} Mg/yr), biosolids (10 × 10{sup 7} Mg/yr), and animal manures (7 × 10{sup 9} Mg/yr) are produced. Recycling these OAs in agriculture possesses several advantages such as improving plant growth, yield, soil carbon content, and microbial biomass and activity. Nevertheless, OA applications hold some disadvantages such as nutrient eutrophication and greenhouse gas (GHG) emission. Agriculture sector plays a vital role in GHG emission (carbon dioxide— CO{sub 2}, methane— CH{sub 4}, and nitrous oxide— N{sub 2}O). Though CH{sub 4} and N{sub 2}O are emitted in less quantity than CO{sub 2}, they are 21 and 310 times more powerful in global warming potential, respectively. Although there have been reviews on the role of mineral fertilizer application on GHG emission, there has been no comprehensive review on the effect of OA application on GHG emission in agricultural soils. The review starts with the quantification of various OAs used in agriculture that include manures, biosolids, and crop residues along with their role in improving soil health. Then, it discusses four major OA induced-GHG emission processes (i.e., priming effect, methanogenesis, nitrification, and denitrification) by highlighting the impact of OA application on GHG emission from soil. For example, globally 10 × 10{sup 7} Mg biosolids are produced annually which can result in the potential emission of 530 Gg of CH{sub 4} and 60 Gg of N{sub 2}O. The article then aims to highlight the soil, climatic, and OA factors affecting OA induced-GHG emission and the management practices to mitigate the emission. This review emphasizes the future research needs in relation to nitrogen and carbon dynamics in soil to broaden the use of OAs in agriculture to maintain soil health with minimum impact on GHG emission from agriculture. - Highlights: ► A comprehensive overview for the first time on GHG emission from

  5. Greenhouse Gas Emissions From Cattle

    Directory of Open Access Journals (Sweden)

    Podkówka Zbigniew

    2015-03-01

    Full Text Available Cattle produce greenhouse gases (GHG which lead to changes in the chemical composition of the atmosphere. These gases which cause greenhouse effect include: methane (CH4, nitrous oxide (N2O, nitrogen oxides (NOx, sulphur dioxide (SO2, ammonia (NH3, dust particles and non-methane volatile organic compounds, commonly described as other than methane hydrocarbons. Fermentation processes taking place in the digestive tract produce ‘digestive gases’, distinguished from gases which are emitted during the decomposition of manure. Among these digestive gases methane and non-methane volatile organic compounds are of particular relevance importance. The amount of gases produced by cows can be reduced by choosing to rear animals with an improved genetically based performance. A dairy cow with higher production efficiency, producing milk with higher protein content and at the same time reduced fat content emits less GHG into the environment. Increasing the ratio of feed mixtures in a feed ration also reduces GHG emissions, especially of methane. By selection of dairy cows with higher production efficiency and appropriate nutrition, the farm's expected milk production target can be achieved while at the same time, the size of the herd is reduced, leading to a reduction of GHG emissions.

  6. Organic Rankine Cycle for Residual Heat to Power Conversion in Natural Gas Compressor Station. Part I: Modelling and Optimisation Framework

    Science.gov (United States)

    Chaczykowski, Maciej

    2016-06-01

    Basic organic Rankine cycle (ORC), and two variants of regenerative ORC have been considered for the recovery of exhaust heat from natural gas compressor station. The modelling framework for ORC systems has been presented and the optimisation of the systems was carried out with turbine power output as the variable to be maximized. The determination of ORC system design parameters was accomplished by means of the genetic algorithm. The study was aimed at estimating the thermodynamic potential of different ORC configurations with several working fluids employed. The first part of this paper describes the ORC equipment models which are employed to build a NLP formulation to tackle design problems representative for waste energy recovery on gas turbines driving natural gas pipeline compressors.

  7. The contributions of biomass burning to primary and secondary organics: A case study in Pearl River Delta (PRD), China.

    Science.gov (United States)

    Wang, BaoLin; Liu, Ying; Shao, Min; Lu, SiHua; Wang, Ming; Yuan, Bin; Gong, ZhaoHeng; He, LingYan; Zeng, LiMin; Hu, Min; Zhang, YuanHang

    2016-11-01

    Synchronized online measurements of gas- and particle- phase organics including non-methane hydrocarbons (NMHCs), oxygenated volatile organic compounds (OVOCs) and submicron organic matters (OM) were conducted in November 2010 at Heshan, Guangdong provincial supersite, China. Several biomass burning events were identified by using acetonitrile as a tracer, and enhancement ratios (EnRs) of organics to carbon monoxide (CO) obtained from this work generally agree with those from rice straw burning in previous studies. The influences of biomass burning on NMHCs, OVOCs and OM were explored by comparing biomass burning impacted plumes (BB plumes) and non-biomass burning plumes (non-BB plumes). A photochemical age-based parameterization method was used to characterize primary emission and chemical behavior of those three organic groups. The emission ratios (EmRs) of NMHCs, OVOCs and OM to CO increased by 27-71%, 34-55% and 67% in BB plumes, respectively, in comparison with non-BB plumes. The estimated formation rate of secondary organic aerosol (SOA) in BB plumes was found to be 24% faster than non-BB plumes. By applying the above emission ratios to the whole PRD, the annual emissions of VOCs and OM from open burning of crop residues would be 56.4 and 3.8Gg in 2010 in PRD, respectively.

  8. Vacuum ultraviolet absorption spectroscopy in combination with comprehensive two-dimensional gas chromatography for the monitoring of volatile organic compounds in breath gas: A feasibility study.

    Science.gov (United States)

    Gruber, Beate; Groeger, Thomas; Harrison, Dale; Zimmermann, Ralf

    2016-09-16

    Vacuum ultraviolet (VUV) absorption spectroscopy was recently introduced as a new detection system for one, as well as comprehensive two-dimensional gas chromatography (GC×GC) and successfully applied to the analysis of various analytes in several matrices. In this study, its suitability for the analysis of breath metabolites was investigated and the impact of a finite volume of the absorption cell and makeup gas pressure was evaluated for volatile analytes in terms of sensitivity and chromatographic resolution. A commercial available VUV absorption spectrometer was coupled to GC×GC and applied to the analysis of highly polar volatile organic compounds (VOCs). Breath gas samples were acquired by needle trap micro extraction (NTME) during a glucose challenge and analysed by the applied technique. Regarding qualitative and quantitative information, the VGA-100 is compatible with common GC×GC detection systems like FID and even TOFMS. Average peak widths of 300ms and LODs in the lower ng range were achieved using GC×GC-VUV. Especially small oxygenated breath metabolites show intense and characteristic absorption patterns in the VUV region. Challenge responsive VOCs could be identified and monitored during a glucose challenge. The new VUV detection technology might especially be of benefit for applications in clinical research.

  9. Distributions of the particle/gas and dust/gas partition coefficients for seventy-two semi-volatile organic compounds in indoor environment.

    Science.gov (United States)

    Wei, Wenjuan; Mandin, Corinne; Blanchard, Olivier; Mercier, Fabien; Pelletier, Maud; Le Bot, Barbara; Glorennec, Philippe; Ramalho, Olivier

    2016-06-01

    Particle/gas and dust/gas partition coefficients (Kp and Kd) are two key parameters that address the partitioning of semi-volatile organic compounds (SVOCs) between gas-phase, airborne particles, and settled dust in indoor environment. A number of empirical equations to calculate the values of Kp and Kd have been reported in the literature. Therefore, the difficulty lies in the selection of a specific empirical equation in a given situation. In this study, we retrieved from the literature 38 empirical equations for calculating Kp and Kd values from the SVOC saturation vapor pressure and octanol/air partition coefficient. These values were calculated for 72 SVOCs: 9 phthalates, 9 polybrominated diphenyl ethers (PBDEs), 11 polychlorinated biphenyls (PCBs), 22 biocides, 14 polycyclic aromatic hydrocarbons (PAHs), 3 alkylphenols, 2 synthetic musks, tributylphosphate, and bisphenol A. The mean and median values of log10Kp or log10Kd for most SVOCs were of the same order of magnitude. The distribution of log10Kp values was fitted to either a normal distribution (for 27 SVOCs) or a log-normal distribution (for 45 SVOCs). This work provides a reference distribution of the log10Kp for 72 SVOCs, and its use may reduce the bias associated with the selection of a specific value or equation.

  10. Activation of Metal-Organic Precursors by Electron Bombardment in the Gas Phase for Enhanced Deposition of Solid Films.

    Science.gov (United States)

    Sun, Huaxing; Qin, Xiangdong; Zaera, Francisco

    2012-09-01

    The incorporation of gas-phase electron-impact ionization and activation of metal-organic compounds into atomic layer deposition (ALD) processes is reported as a way to enhance film growth with stable precursors. Specifically, it is shown here that gas-phase activation of methylcyclopentadienylmanganese tricarbonyl, MeCpMn(CO)3, which was accomplished by using a typical nude ion gauge employed in many ultrahigh-vacuum (UHV) studies, enhances its dissociative adsorption on silicon surfaces, affording the design of ALD cycles with more extensive Mn deposition and at lower temperatures. Significantly higher Mn uptakes were demonstrated by X-ray photoelectron spectroscopy (XPS) on both silicon dioxide films and on Si(100) wafers Ar(+)-sputtered to remove their native oxide layer. The effectiveness of this electron-impact activation approach in ALD is explained in terms of the cracking patterns seen in mass spectrometry for the metal-organic precursor used.

  11. Soil properties, crop production and greenhouse gas emissions from organic and inorganic fertilizer-based arable cropping systems

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Olesen, Jørgen Eivind; Porter, John Roy

    2010-01-01

    Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy...... conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop...... growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley...

  12. Kinetic modeling of Secondary Organic Aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

    Directory of Open Access Journals (Sweden)

    A. W. H. Chan

    2007-05-01

    Full Text Available The distinguishing mechanism of formation of secondary organic aerosol (SOA is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics, of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

  13. Kinetic modeling of secondary organic aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

    Directory of Open Access Journals (Sweden)

    A. W. H. Chan

    2007-08-01

    Full Text Available The distinguishing mechanism of formation of secondary organic aerosol (SOA is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics, of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

  14. Flue-gas and direct-air capture of CO2 by porous metal-organic materials.

    Science.gov (United States)

    Madden, David G; Scott, Hayley S; Kumar, Amrit; Chen, Kai-Jie; Sanii, Rana; Bajpai, Alankriti; Lusi, Matteo; Curtin, Teresa; Perry, John J; Zaworotko, Michael J

    2017-01-13

    Sequestration of CO2, either from gas mixtures or directly from air (direct air capture), is a technological goal important to large-scale industrial processes such as gas purification and the mitigation of carbon emissions. Previously, we investigated five porous materials, three porous metal-organic materials (MOMs), a benchmark inorganic material, ZEOLITE 13X: and a chemisorbent, TEPA-SBA-15: , for their ability to adsorb CO2 directly from air and from simulated flue-gas. In this contribution, a further 10 physisorbent materials that exhibit strong interactions with CO2 have been evaluated by temperature-programmed desorption for their potential utility in carbon capture applications: four hybrid ultramicroporous materials, SIFSIX-3-CU: , DICRO-3-NI-I: , SIFSIX-2-CU-I: and MOOFOUR-1-NI: ; five microporous MOMs, DMOF-1: , ZIF-8: , MIL-101: , UIO-66: and UIO-66-NH2: ; an ultramicroporous MOM, NI-4-PYC: The performance of these MOMs was found to be negatively impacted by moisture. Overall, we demonstrate that the incorporation of strong electrostatics from inorganic moieties combined with ultramicropores offers improved CO2 capture performance from even moist gas mixtures but not enough to compete with chemisorbents.This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  15. Flue-gas and direct-air capture of CO2 by porous metal-organic materials

    Science.gov (United States)

    Madden, David G.; Scott, Hayley S.; Kumar, Amrit; Chen, Kai-Jie; Sanii, Rana; Bajpai, Alankriti; Lusi, Matteo; Curtin, Teresa; Perry, John J.; Zaworotko, Michael J.

    2017-01-01

    Sequestration of CO2, either from gas mixtures or directly from air (direct air capture), is a technological goal important to large-scale industrial processes such as gas purification and the mitigation of carbon emissions. Previously, we investigated five porous materials, three porous metal-organic materials (MOMs), a benchmark inorganic material, Zeolite 13X and a chemisorbent, TEPA-SBA-15, for their ability to adsorb CO2 directly from air and from simulated flue-gas. In this contribution, a further 10 physisorbent materials that exhibit strong interactions with CO2 have been evaluated by temperature-programmed desorption for their potential utility in carbon capture applications: four hybrid ultramicroporous materials, SIFSIX-3-Cu, DICRO-3-Ni-i, SIFSIX-2-Cu-i and MOOFOUR-1-Ni; five microporous MOMs, DMOF-1, ZIF-8, MIL-101, UiO-66 and UiO-66-NH2; an ultramicroporous MOM, Ni-4-PyC. The performance of these MOMs was found to be negatively impacted by moisture. Overall, we demonstrate that the incorporation of strong electrostatics from inorganic moieties combined with ultramicropores offers improved CO2 capture performance from even moist gas mixtures but not enough to compete with chemisorbents. This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  16. Microbial lipid signatures and substrate potential of organic matter in permafrost deposits: Implications for future greenhouse gas production

    Science.gov (United States)

    Stapel, J. G.; Schirrmeister, L.; Overduin, P. P.; Wetterich, S.; Strauss, J.; Horsfield, B.; Mangelsdorf, K.

    2016-10-01

    A terrestrial permafrost core from Buor Khaya in northern Siberia comprising deposits of Late Pleistocene to Early Holocene age has been investigated to characterize living and past microbial communities with respect to modern and paleoclimate environmental conditions and to evaluate the potential of the organic matter (OM) for greenhouse gas generation. Microbial life markers—intact phospholipids and phospholipid fatty acids—are found throughout the entire core and indicate the presence of living microorganisms also in older permafrost deposits. Biomarkers for past microbial communities (branched and isoprenoid glycerol dialkyl glycerol tetraether as well as archaeol) reveal links between increased past microbial activity and intervals of high OM accumulation accompanied by increased OM quality presumably caused by local periods of moister and warmer environmental conditions. Concentrations of acetate as an excellent substrate for methanogenesis are used to assess the OM quality with respect to microbial degradability for greenhouse gas production. For this purpose two acetate pools are determined: the pore water acetate and OM bound acetate. Both depth profiles reveal similarities to the OM content and quality indicating a link between the amount of the stored OM and the potential to provide substrates for microbial greenhouse gas production. The data suggest that OM stored in the permafrost deposits is not much different in terms of OM quality than the fresh surface organic material. Considering the expected increase of permafrost thaw due to climate warming, this implies a potentially strong impact on greenhouse gas generation from permafrost areas in future with positive feedback on climate variation.

  17. Characterization of Crew Refuse Returned from Shuttle Missions with Permanent Gas, Volatile Organic Compound, and Microbial Analyses

    Science.gov (United States)

    Peterson, B.; Hummerick, M.; Roberts, M.; Krummins, V.; Kish, A.; Garland, J.; Maxwell, S.; Mills, A.

    In addition to the mass and energy costs associated with bioregenerative systems for advanced life support, the storage and processing of waste on spacecraft requires both atmospheric and biological management. Risks to crew health may arise from the presence of potential human pathogens in waste or from decay processes during waste storage and/or processing. This study reports on the permanent gas, trace volatile organic and microbiological analyses of crew refuse returned from shuttle missions STS-105, 109 and 110. The research objective is to characterize the biological stability of the waste stream, to assess the risks associated with its storage, and to provide baseline measures for the evaluation of waste processing technologies. Microbiological samples were collected from packaging material, food waste, bathroom waste, and bulk liquid collected from the volume F waste container. The number of culturable bacteria and total bacteria were determined by plating on R2A media and by Acridine Orange direct count, respectively. Samples of the trash were analyzed for the presence of fecal and total coliforms and other human-associated bacteria. Dry and ash weights were determined to estimate both water and organic content of the materials. The aerobic and anaerobic bio-stability of stored waste was determined by on-line monitoring of CO2 and by laboratory analysis of off-gas samples for hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA method TO15 with gas chromatography/mass spectrometry and by gas chromatography with selective detectors . This study establishes a baseline measure of waste composition, labile organics, and microbial load for this material.

  18. Gas production, composition and emission at a modern disposal site receiving waste with a low-organic content

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Fredenslund, Anders Michael; Nedenskov, Jonas

    2011-01-01

    AV Miljø is a modern waste disposal site receiving non-combustible waste with a low-organic content. The objective of the current project was to determine the gas generation, composition, emission, and oxidation in top covers on selected waste cells as well as the total methane (CH4) emission fro...... drainage pipes placed in permeable gravel layers in the bottom of empty cells was likely....... the disposal site. The investigations focused particularly on three waste disposal cells containing shredder waste (cell 1.5.1), mixed industrial waste (cell 2.2.2), and mixed combustible waste (cell 1.3). Laboratory waste incubation experiments as well as gas modeling showed that significant gas generation...... was occurring in all three cells. Field analysis showed that the gas generated in the cell with mixed combustible waste consisted of mainly CH4 (70%) and carbon dioxide (CO2) (29%) whereas the gas generated within the shredder waste, primarily consisted of CH4 (27%) and nitrogen (N2) (71%), containing no CO2...

  19. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  20. Organic nitrate and secondary organic aerosol yield from NO3 oxidation of β-pinene evaluated using a gas-phase kinetics/aerosol partitioning model

    Directory of Open Access Journals (Sweden)

    H.-P. Dorn

    2008-10-01

    Full Text Available The yields of organic nitrates and of secondary organic aerosol (SOA particle formation were measured for the reaction NO3+β-pinene under dry and humid conditions in the atmosphere simulation chamber SAPHIR at Research Center Jülich. These experiments were conducted at low concentrations of NO3 (NO3+N2O5β-pinene (peak~15 ppb, with no seed aerosol. SOA formation was observed to be prompt and substantial (~50% mass yield under both dry conditions and at 60% RH, and highly correlated with organic nitrate formation. The observed gas/aerosol partitioning of organic nitrates can be simulated using an absorptive partitioning model to derive an estimated vapor pressure of the condensing nitrate species of pvap~5×10−6 Torr (6.67×10−4 Pa, which constrains speculation about the oxidation mechanism and chemical identity of the organic nitrate. Once formed the SOA in this system continues to evolve, resulting in measurable aerosol volume decrease with time. The observations of high aerosol yield from NOx-dependent oxidation of monoterpenes provide an example of a significant anthropogenic source of SOA from biogenic hydrocarbon precursors. Estimates of the NO3+β-pinene SOA source strength for California and the globe indicate that NO3 reactions with monoterpenes are likely an important source (0.5–8% of the global total of organic aerosol on regional and global scales.

  1. Humus and energy balances and greenhouse gas emissions with compost fertilization in organic farming compared with mineral fertilization

    Science.gov (United States)

    Erhart, Eva; Schmid, Harald; Hülsbergen, Kurt-Jürgen; Hartl, Wilfried

    2015-04-01

    Humus and energy balances and greenhouse gas emissions with compost fertilization in organic farming compared with mineral fertilization E. Erhart, H. Schmid, K.-J. Hülsbergen, W. Hartl The positive effects of compost fertilization on soil humus with their associated benefits for soil quality are well-established. The aim of the present study was to assess the effect of compost fertilization on humus and energy balances and greenhouse gas emissions and to compare the results of the humus balances with the changes in soil organic carbon contents measured in the soil of the experimental field. In order to assess the effects of compost use in organic farming as compared to conventional farming practice using mineral fertilizers, the field experiment with compost fertilization 'STIKO' was set up in 1992 near Vienna, Austria, on a Molli-gleyic Fluvisol. It included three treatments with compost fertilization (C1, C2 and C3 with 8, 14 and 20 t ha-1 y-1 f. m. on average of 14 years), three treatments with mineral nitrogen fertilization (N1, N2 and N3 with 29, 46 and 63 kg N ha-1 y 1 on average) and an unfertilized control (0) in six replications in a latin rectangle design. In the field trial, biowaste compost from the composting plant of the City of Vienna was used. Data from the field experiment (from 14 experimental years) were fed into the model software REPRO to calculate humus and energy balances and greenhouse gas emissions. The model software REPRO (REPROduction of soil fertility) couples the balancing of C, N and energy fluxes. For the determination of the net greenhouse effect, REPRO performs calculations of C sequestration in the soil, CO2 emissions from the use of fossil energy and N2O emissions from the soil. Humus balances showed that compost fertilization at a rate of 8 t ha-1 y-1 (C1) resulted in a positive humus balance of +115 kg C ha-1 y-1. With 14 and 20 t ha-1 y-1 compost (C2 and C3), respectively, humus accumulated at rates of 558 and 1021 kg C ha-1

  2. Investigating the gas sorption mechanism in an rht -metal-organic framework through computational studies

    KAUST Repository

    Pham, Tony T.

    2014-01-09

    Grand canonical Monte Carlo (GCMC) simulations were performed to investigate CO2 and H2 sorption in an rht-metal-organic framework (MOF) that was synthesized with a ligand having a nitrogen-rich trigonal core through trisubstituted triazine groups and amine functional groups. This MOF was synthesized by two different groups, each reporting their own distinct gas sorption measurements and crystal structure. Electronic structure calculations demonstrated that the small differences in the atomic positions between each group\\'s crystal structure resulted in different electrostatic parameters about the Cu2+ ions for the respective unit cells. Simulations of CO2 sorption were performed with and without many-body polarization effects and using our recently developed CO2 potentials, in addition to a well-known bulk CO2 model, in both crystallographic unit cells. Simulated CO2 sorption isotherms and calculated isosteric heats of adsorption, Qst, values were in excellent agreement with the results reported previously by Eddaoudi et al. for both structures using the polarizable CO2 potential. For both crystal structures, the initial site for CO2 sorption were the Cu 2+ ions that had the higher positive charge in the unit cell, although the identity of this electropositive Cu2+ ion was different in each case. Simulations of H2 sorption were performed with three different hydrogen potentials of increasing anisotropy in both crystal structures and the results, especially with the highest fidelity model, agreed well with Eddaoudi et al.\\'s experimental data. The preferred site of H 2 sorption at low loading was between two Cu2+ ions of neighboring paddlewheels. The calculation of the normalized hydrogen dipole distribution for the polarizable model in both crystal structures aided in the identification of four distinct sorption sites in the MOF, which is consistent to what was observed in the experimental inelastic neutron scattering (INS) spectra. Lastly, while the

  3. Gas Phase Sensing of Alcohols by Metal Organic Framework–Polymer Composite Materials

    Science.gov (United States)

    2017-01-01

    Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH2-MIL-53(Al) were dispersed in a Matrimid polymer matrix with different weight ratios (0–100 wt %) and drop-casted on planar capacitive transducer devices. These coated devices were electrically analyzed using impedance spectroscopy and investigated for their sensing properties toward the detection of a series of alcohols and water in the gas phase. The measurements indicated a reversible and reproducible response in all devices. Sensor devices containing 40 wt % NH2-MIL-53(Al) in Matrimid showed a maximum response for methanol and water. The sensor response time slowed down with increasing MOF concentration until 40 wt %. The half time of saturation response (τ0.5) increased by ∼1.75 times for the 40 wt % composition compared to devices coated with Matrimid only. This is attributed to polymer rigidification near the MOF/polymer interface. Higher MOF loadings (≥50 wt %) resulted in brittle coatings with a response similar to the 100 wt % MOF coating. Cross-sensitivity studies showed the ability to kinetically distinguish between the different alcohols with a faster response for methanol and water compared to ethanol and 2-propanol. The observed higher affinity of the pure Matrimid polymer toward methanol compared to water allows also for a higher uptake of methanol in the composite matrices. Also, as indicated by the sensing studies with a mixture of water and methanol, the methanol uptake is independent of the presence of water up to 6000 ppm of water. The NH2-MIL-53(Al) MOFs dispersed in the Matrimid matrix show a sensitive and reversible capacitive response, even in the presence of water. By tuning the precise compositions, the affinity kinetics and overall affinity can be tuned, showing

  4. Investigation of Integrated Subsurface Processing of Landfill Gas and Carbon Sequestration, Johnson County, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    K. David Newell; Timothy R. Carr

    2007-03-31

    The Johnson County Landfill in Shawnee, KS is operated by Deffenbaugh Industries and serves much of metropolitan Kansas City. Refuse, which is dumped in large plastic-underlined trash cells covering several acres, is covered over with shale shortly after burial. The landfill waste, once it fills the cell, is then drilled by Kansas City LFG, so that the gas generated by anaerobic decomposition of the refuse can be harvested. Production of raw landfill gas from the Johnson County landfill comes from 150 wells. Daily production is approximately 2.2 to 2.5 mmcf, of which approximately 50% is methane and 50% is carbon dioxide and NMVOCs (non-methane volatile organic compounds). Heating value is approximately 550 BTU/scf. A upgrading plant, utilizing an amine process, rejects the carbon dioxide and NMVOCs, and upgrades the gas to pipeline quality (i.e., nominally a heating value >950 BTU/scf). The gas is sold to a pipeline adjacent to the landfill. With coal-bearing strata underlying the landfill, and carbon dioxide a major effluent gas derived from the upgrading process, the Johnson County Landfill is potentially an ideal setting to study the feasibility of injecting the effluent gas in the coals for both enhanced coalbed methane recovery and carbon sequestration. To these ends, coals below the landfill were cored and then were analyzed for their thickness and sorbed gas content, which ranged up to 79 scf/ton. Assuming 1 1/2 square miles of land (960 acres) at the Johnson County Landfill can be utilized for coalbed and shale gas recovery, the total amount of in-place gas calculates to 946,200 mcf, or 946.2 mmcf, or 0.95 bcf (i.e., 985.6 mcf/acre X 960 acres). Assuming that carbon dioxide can be imbibed by the coals and shales on a 2:1 ratio compared to the gas that was originally present, then 1682 to 1720 days (4.6 to 4.7 years) of landfill carbon dioxide production can be sequestered by the coals and shales immediately under the landfill. Three coal--the Bevier

  5. Organic compounds in produced waters from coalbed natural gas wells in the Powder River Basin, Wyoming, USA

    Science.gov (United States)

    Orem, W.H.; Tatu, C.A.; Lerch, H.E.; Rice, C.A.; Bartos, T.T.; Bates, A.L.; Tewalt, S.; Corum, M.D.

    2007-01-01

    The organic composition of produced water samples from coalbed natural gas (CBNG) wells in the Powder River Basin, WY, sampled in 2001 and 2002 are reported as part of a larger study of the potential health and environmental effects of organic compounds derived from coal. The quality of CBNG produced waters is a potential environmental concern and disposal problem for CBNG producers, and no previous studies of organic compounds in CBNG produced water have been published. Organic compounds identified in the produced water samples included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, various non-aromatic compounds, and phthalates. Many of the identified organic compounds (phenols, heterocyclic compounds, PAHs) are probably coal-derived. PAHs represented the group of organic compounds most commonly observed. Concentrations of total PAHs ranged up to 23 ??g/L. Concentrations of individual compounds ranged from about 18 to compound concentrations was documented, as two wells with relatively high organic compound contents in produced water in 2001 had much lower concentrations in 2002. In many areas, including the PRB, coal strata provide aquifers for drinking water wells. Organic compounds observed in produced water are also likely present in drinking water supplied from wells in the coal. Some of the organic compounds identified in the produced water samples are potentially toxic, but at the levels measured in these samples are unlikely to have acute health effects. The human health effects of low-level, chronic exposure to coal-derived organic compounds in drinking water are currently unknown. Continuing studies will evaluate possible toxic effects from low level, chronic exposure to coal-derived organic compounds in drinking water supplies.

  6. 2D Time-lapse Resistivity Monitoring of an Organic Produced Gas Plume in a Landfill using ERT.

    Science.gov (United States)

    Amaral, N. D.; Mendonça, C. A.; Doherty, R.

    2014-12-01

    This project has the objective to study a landfill located on the margins of Tietê River, in São Paulo, Brazil, using the electroresistivity tomography method (ERT). Due to huge organic matter concentrations in the São Paulo Basin quaternary sediments, there is subsurface depth related biogas accumulation (CH4 and CO2), induced by anaerobic degradation of the organic matter. 2D resistivity sections were obtained from a test area since March 2012, a total of 7 databases, being the last one dated from October 2013. The studied line has the length of 56m, the electrode interval is of 2m. In addition, there are two boreholes along the line (one with 3 electrodes and the other one with 2) in order to improve data quality and precision. The boreholes also have a multi-level sampling system that indicates the fluid (gas or water) presence in relation to depth. With our results it was possible to map the gas plume position and its area of extension in the sections as it is a positive resistivity anomaly, with the gas level having approximately 5m depth. With the time-lapse analysis (Matlab script) between the obtained 2D resistivity sections from the site, it was possible to map how the biogas volume and position change in the landfill in relation to time. Our preliminary results show a preferential gas pathway through the subsurface studied area. A consistent relation between the gas depth and obtained microbiological data from archea and bacteria population was also observed.

  7. Reducing agricultural greenhouse gas emissions: role of biotechnology, organic systems, and consumer behavior

    Science.gov (United States)

    All agricultural systems have environmental and societal costs and benefits that should be objectively quantified before recommending specific management practices. Agricultural biotechnology, which takes advantage of genetically engineered organisms (GEOs), along with organic cropping systems, econ...

  8. Sorbent-coated diffusion denuders for direct measurement of gas/particle partitioning by semi-volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gundel, L.A. [Lawrence Berkeley National Lab., CA (United States); Lane, D.A. [Atmospheric Environment Service, North York, Ontario (Canada)

    1998-01-01

    Sorbent-coated annular denuder-based samplers have been developed for direct determination of both gaseous and particulate semi-volatile organic species. The first such sampler, the Integrated Organic Vapor/Particle Sampler, has been validated for sampling semi-volatile PAH in ambient air and environmental tobacco smoke. Multi-channel versions of the IOVPS have been used successfully for investigation of gas/particle partitioning of a variety of semi-volatile organic species in combustion source-enriched environmental chambers. Subsequent improvements have resulted in two new higher-capacity samplers, the IOGAPS and the jumbo-IOGAPS, that use the same sorbent for sampling trace organics in the ambient atmosphere for 24--48 hr periods over a wide temperature range. Construction of these new samplers began by incorporating the IOVPS coating technology onto the gas collection surfaces of the higher capacity GAP sampler. Substantial design effort aims to ensure that vapor phase components as volatile as naphthalene can be trapped efficiently and retained by the sorbent-coated surface while the particles pass through to the filter.

  9. The Reality of Project Management Office for Construction Organization in the Oil, Gas and Petrochemical Industry of Iran

    Directory of Open Access Journals (Sweden)

    Homayoun Izadpanah

    2012-08-01

    Full Text Available Over the last decade, the Project Management Office (PMO has become a prominent feature in many organizations. Despite the proliferation of PMO in practice, our understanding of this phenomenon remains sketchy at best. The objective of this study is describing the reality of PMOs for Construction Organization in the Oil, Gas and Petrochemical Industry of Iran at 2010 year. Nine major Iranian oil, gas and petrochemical organizations were participated in this survey. The study examines the reality of PMOs, the age of PMOs, the reason for their implementation and challenges during their implementation. Research concludes that PMO are a new concept and nearly 60% of PMOs have been in existence for 3 years. Monitoring project performance, supporting project management software tools and preparing project management methodology are the most used functions. Organizations are using PMOs to achieve the golden triangle project objectives (cost/time/quality. The study found that the most significant challenges in PMO implementation are the risk of changing organizational culture and the lack of professional staff.

  10. Effect of organic-matter type and thermal maturity on methane adsorption in shale-gas systems

    Science.gov (United States)

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Yang, Rongsheng

    2012-01-01

    A series of methane (CH4) adsorption experiments on bulk organic rich shales and their isolated kerogens were conducted at 35 °C, 50 °C and 65 °C and CH4 pressure of up to 15 MPa under dry conditions. Samples from the Eocene Green River Formation, Devonian–Mississippian Woodford Shale and Upper Cretaceous Cameo coal were studied to examine how differences in organic matter type affect natural gas adsorption. Vitrinite reflectance values of these samples ranged from 0.56–0.58 %Ro. In addition, thermal maturity effects were determined on three Mississippian Barnett Shale samples with measured vitrinite reflectance values of 0.58, 0.81 and 2.01 %Ro. For all bulk and isolated kerogen samples, the total amount of methane adsorbed was directly proportional to the total organic carbon (TOC) content of the sample and the average maximum amount of gas sorption was 1.36 mmol of methane per gram of TOC. These results indicate that sorption on organic matter plays a critical role in shale-gas storage. Under the experimental conditions, differences in thermal maturity showed no significant effect on the total amount of gas sorbed. Experimental sorption isotherms could be fitted with good accuracy by the Langmuir function by adjusting the Langmuir pressure (PL) and maximum sorption capacity (Γmax). The lowest maturity sample (%Ro = 0.56) displayed a Langmuir pressure (PL) of 5.15 MPa, significantly larger than the 2.33 MPa observed for the highest maturity (%Ro > 2.01) sample at 50 °C. The value of the Langmuir pressure (PL) changes with kerogen type in the following sequence: type I > type II > type III. The thermodynamic parameters of CH4 adsorption on organic rich shales were determined based on the experimental CH4 isotherms. For the adsorption of CH4 on organic rich shales and their isolated kerogen, the heat of adsorption (q) and the standard entropy (Δs0) range from 7.3–28.0 kJ/mol and from −36.2 to −92.2 J/mol/K, respectively.

  11. Study Analysis of Flue Gas Utilization as Alternative Power Generation in Cement Plant Using Organic Rankine Cycle System

    Directory of Open Access Journals (Sweden)

    Rahmat Ranggonang Anwar

    2017-01-01

    Full Text Available Abstract—Cement plant produce large amount of heat source in cement making process, due to inefficiency of system there still waste heat available in form of flue gas that can be utilize. Flue gas  in cement plant can be utilized as alternative power generation. With the 200-300oC temperature output range of flue gas from suspension preheater and air quenching cooler (AQC in cement plant, organic rankine cycle (ORC can be suitable option for alternative power generation. ORC is development of rankine cycle, the different is the working fluid in ORC using refrigerant. In cement plant that produce 8466 TPD kiln production, used flue gas from suspension preheater to dry raw material and produce 163888 m3/h flue gas from AQC that still not utilized. Flue gas with 235oC temperature from AQC can utilized for power generation purpose using ORC system. Waste heat recovery calculation carried out to know the potential recovery. Operating condition of the ORC system will determine power produced that can be generated and ORC components calculated and selected according to the operating condition of the system. Using R141b as working fluid with 8 bar pressure and 110oC temperature inlet to turbine, power produced by turbine is 666 kW. For the components, evaporator and condenser use shell and tube heat exchanger, with evaporator heat transfer area is 676.49 m2 while condenser has 510 m2 of heat transfer area. And for working fluid pump it needs 16.235 Kw power to pump R141b back to evaporator.

  12. Uranium and organic matters: use of pyrolysis-gas chromatography, carbon, hydrogen, and uranium contents to characterize the organic matter from sandstone-type deposits

    Science.gov (United States)

    Leventhal, Joel S.

    1979-01-01

    Organic matter seems to play an important role in the genesis of uranium deposits in sandstones in the western United States. Organic materials associated with ore from the Texas coastal plain, Tertiary basins of Wyoming, Grants mineral belt of New Mexico, and the Uravan mineral belt of Utah and Colorado vary widely in physical appearance and chemical composition. Partial characterization of organic materials is achieved by chemical analyses to determine atomic hydrogen-to-carbon (H/C) ratios and by gas chromatographic analyses to determine the molecular fragments evolved during stepwise pyrolysis. From the pyrolysis experiments the organic materials can be classified and grouped: (a) lignites from Texas and Wyoming and (b) hydrogen poor materials, from Grants and Uravan mineral belts and Wyoming; (c) naphthalene-containing materials from Grants mineral belt and Wyoming; and (d) complex and aromatic materials from Uravan, Grants and Wyoming. The organic materials analyzed have atomic H/C ratios that range from approximately 0.3 to at least 1.5. The samples with higher H/C ratios yield pyrolysis products that contain as many as 30 carbon atoms per molecule. Samples with low H/C ratios are commonly more uraniferous and yield mostly methane and low-molecular-weight gases during pyrolysis.

  13. An improved, automated whole air sampler and gas chromatography mass spectrometry analysis system for volatile organic compounds in the atmosphere

    Science.gov (United States)

    Lerner, Brian M.; Gilman, Jessica B.; Aikin, Kenneth C.; Atlas, Elliot L.; Goldan, Paul D.; Graus, Martin; Hendershot, Roger; Isaacman-VanWertz, Gabriel A.; Koss, Abigail; Kuster, William C.; Lueb, Richard A.; McLaughlin, Richard J.; Peischl, Jeff; Sueper, Donna; Ryerson, Thomas B.; Tokarek, Travis W.; Warneke, Carsten; Yuan, Bin; de Gouw, Joost A.

    2017-01-01

    Volatile organic compounds were quantified during two aircraft-based field campaigns using highly automated, whole air samplers with expedited post-flight analysis via a new custom-built, field-deployable gas chromatography-mass spectrometry instrument. During flight, air samples were pressurized with a stainless steel bellows compressor into electropolished stainless steel canisters. The air samples were analyzed using a novel gas chromatograph system designed specifically for field use which eliminates the need for liquid nitrogen. Instead, a Stirling cooler is used for cryogenic sample pre-concentration at temperatures as low as -165 °C. The analysis system was fully automated on a 20 min cycle to allow for unattended processing of an entire flight of 72 sample canisters within 30 h, thereby reducing typical sample residence times in the canisters to less than 3 days. The new analytical system is capable of quantifying a wide suite of C2 to C10 organic compounds at part-per-trillion sensitivity. This paper describes the sampling and analysis systems, along with the data analysis procedures which include a new peak-fitting software package for rapid chromatographic data reduction. Instrument sensitivities, uncertainties and system artifacts are presented for 35 trace gas species in canister samples. Comparisons of reported mixing ratios from each field campaign with measurements from other instruments are also presented.

  14. Influence of Oil and Gas Emissions on Ambient Atmospheric Volatile Organic Compounds in Residential Areas of Northeastern Colorado

    Science.gov (United States)

    Thompson, C. R.; Evans, J. M.; Wang, W.; Jacques, H.; Smith, K. R.; Terrell, R.; Helmig, D.

    2014-12-01

    The Northern Front Range (NFR) region of Colorado has experienced rapid expansion in drilling of shale and tight sands oil and gas reservoirs in recent years due to advances in hydraulic fracturing technology, with over 24,000 wells currently in operation. This region has also been designated as a federal ozone non-attainment area by the U.S. EPA. High ozone levels are a significant health concern, as are potential health impacts from chronic exposure to primary emissions of volatile organic compounds (VOC) for residents living near wells. Here we present observations of ambient atmospheric VOC present in residential areas located in close proximity to wells in Erie, Colorado, and show that the C2-C5 alkanes are enhanced by a factor of 18 - 77 relative to the regional background, and present at higher levels than typically found in large urban centers. These data are combined with VOC observations from downtown Denver and Platteville, as well as with measurements conducted this summer in conjunction with the FRAPPE and DISCOVER-AQ flight campaigns, to investigate the spatial distribution of VOC enhancements in correlation with proximity to oil and gas production areas. We show that these compounds, including the BTEX aromatics, are elevated across the NFR, with highest levels in communities within the Greater Wattenberg Gas Field. These analyses demonstrate that VOC emissions from oil and gas operations represent a large area source for ozone precursors in the NFR.

  15. Final Report on Testing of Off-Gas Treatment Technologies for Abatement of Atmospheric Emissions of Chlorinated Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Jarosch, T.R.; Haselow, J.S.; Rossabi, J.; Burdick, S.A.; Raymond, R.; Young, J.E.; Lombard, K.H.

    1995-01-23

    The purpose of this report is to summarize the results of the program for off-gas treatment of atmospheric emissions of chlorinated volatile organic compounds (CVOCs), in particular trichloroethylene (TCE) and perchloroethylene (PCE). This program was funded through the Department of Energy Office of Technology Development`s VOC`s in Non-Arid Soils Integrated Demonstration (VNID). The off-gas treatment program was initiated after testing of in-situ air stripping with horizontal wells was completed (Looney et al., 1991). That successful test expectedly produced atmospheric emissions of CVOCs that were unabated. It was decided after that test that an off-gas treatment is an integral portion of remediation of CVOC contamination in groundwater and soil but also because several technologies were being developed across the United States to mitigate CVOC emissions. A single platform for testing off-gas treatment technologies would facilitate cost effective evaluation of the emerging technologies. Another motivation for the program is that many CVOCs will be regulated under the Clean Air Act Amendments of 1990 and are already regulated by many state regulatory programs. Additionally, compounds such as TCE and PCE are pervasive subsurface environmental contaminants, and, as a result, a small improvement in terms of abatement efficiency or cost will significantly reduce CVOC discharges to the environment as well as costs to United States government and industry.

  16. Screening metal-organic frameworks for selective noble gas adsorption in air: effect of pore size and framework topology.

    Science.gov (United States)

    Parkes, Marie V; Staiger, Chad L; Perry, John J; Allendorf, Mark D; Greathouse, Jeffery A

    2013-06-21

    The adsorption of noble gases and nitrogen by sixteen metal-organic frameworks (MOFs) was investigated using grand canonical Monte Carlo simulation. The MOFs were chosen to represent a variety of net topologies, pore dimensions, and metal centers. Three commercially available MOFs (HKUST-1, AlMIL-53, and ZIF-8) and PCN-14 were also included for comparison. Experimental adsorption isotherms, obtained from volumetric and gravimetric methods, were used to compare krypton, argon, and nitrogen uptake with the simulation results. Simulated trends in gas adsorption and predicted selectivities among the commercially available MOFs are in good agreement with experiment. In the low pressure regime, the expected trend of increasing adsorption with increasing noble gas polarizabilty is seen. For each noble gas, low pressure adsorption correlates with several MOF properties, including free volume, topology, and metal center. Additionally, a strong correlation exists between the Henry's constant and the isosteric heat of adsorption for all gases and MOFs considered. Finally, we note that the simulated and experimental gas selectivities demonstrated by this small set of MOFs show improved performance compared to similar values reported for zeolites.

  17. Reversal of global atmospheric ethane and propane trends largely due to US oil and natural gas production

    Science.gov (United States)

    Helmig, Detlev; Rossabi, Samuel; Hueber, Jacques; Tans, Pieter; Montzka, Stephen A.; Masarie, Ken; Thoning, Kirk; Plass-Duelmer, Christian; Claude, Anja; Carpenter, Lucy J.; Lewis, Alastair C.; Punjabi, Shalini; Reimann, Stefan; Vollmer, Martin K.; Steinbrecher, Rainer; Hannigan, James W.; Emmons, Louisa K.; Mahieu, Emmanuel; Franco, Bruno; Smale, Dan; Pozzer, Andrea

    2016-07-01

    Non-methane hydrocarbons such as ethane are important precursors to tropospheric ozone and aerosols. Using data from a global surface network and atmospheric column observations we show that the steady decline in the ethane mole fraction that began in the 1970s halted between 2005 and 2010 in most of the Northern Hemisphere and has since reversed. We calculate a yearly increase in ethane emissions in the Northern Hemisphere of 0.42 (+/-0.19) Tg yr-1 between mid-2009 and mid-2014. The largest increases in ethane and the shorter-lived propane are seen over the central and eastern USA, with a spatial distribution that suggests North American oil and natural gas development as the primary source of increasing emissions. By including other co-emitted oil and natural gas non-methane hydrocarbons, we estimate a Northern Hemisphere total non-methane hydrocarbon yearly emission increase of 1.2 (+/-0.8) Tg yr-1. Atmospheric chemical transport modelling suggests that these emissions could augment summertime mean surface ozone by several nanomoles per mole near oil and natural gas production regions. Methane/ethane oil and natural gas emission ratios could suggest a significant increase in associated methane emissions; however, this increase is inconsistent with observed leak rates in production regions and changes in methane's global isotopic ratio.

  18. Vadose zone attenuation of organic compounds at a crude oil spill site - Interactions between biogeochemical reactions and multicomponent gas transport

    Science.gov (United States)

    Molins, S.; Mayer, K.U.; Amos, R.T.; Bekins, B.A.

    2010-01-01

    Contaminant attenuation processes in the vadose zone of a crude oil spill site near Bemidji, MN have been simulated with a reactive transport model that includes multicomponent gas transport, solute transport, and the most relevant biogeochemical reactions. Dissolution and volatilization of oil components, their aerobic and anaerobic degradation coupled with sequential electron acceptor consumption, ingress of atmospheric O2, and the release of CH4 and CO2 from the smear zone generated by the floating oil were considered. The focus of the simulations was to assess the dynamics between biodegradation and gas transport processes in the vadose zone, to evaluate the rates and contributions of different electron accepting processes towards vadose zone natural attenuation, and to provide an estimate of the historical mass loss. Concentration distributions of reactive (O2, CH4, and CO2) and non-reactive (Ar and N2) gases served as key constraints for the model calibration. Simulation results confirm that as of 2007, the main degradation pathway can be attributed to methanogenic degradation of organic compounds in the smear zone and the vadose zone resulting in a contaminant plume dominated by high CH4 concentrations. In accordance with field observations, zones of volatilization and CH4 generation are correlated to slightly elevated total gas pressures and low partial pressures of N2 and Ar, while zones of aerobic CH4 oxidation are characterized by slightly reduced gas pressures and elevated concentrations of N2 and Ar. Diffusion is the most significant transport mechanism for gases in the vadose zone; however, the simulations also indicate that, despite very small pressure gradients, advection contributes up to 15% towards the net flux of CH4, and to a more limited extent to O2 ingress. Model calibration strongly suggests that transfer of biogenically generated gases from the smear zone provides a major control on vadose zone gas distributions and vadose zone carbon

  19. A lead-porphyrin metal-organic framework: gas adsorption properties and electrocatalytic activity for water oxidation.

    Science.gov (United States)

    Dai, Fangna; Fan, Weidong; Bi, Jiahui; Jiang, Peng; Liu, Dandan; Zhang, Xirui; Lin, Huan; Gong, Chuanfang; Wang, Rongming; Zhang, Liangliang; Sun, Daofeng

    2016-01-07

    A 3D non-interpenetrating porous metal-organic framework [Pb2(H2TCPP)]·4DMF·H2O (Pb-TCPP) (H6TCPP = 5,10,15,20-tetra(carboxyphenyl)porphyrin) was synthesized by employment of a robust porphyrin ligand. Pb-TCPP exhibits a one-dimensional channel possessing fairly good capability of gas sorption for N2, H2, Ar, and CO2 gases, and also features selectivity for CO2 over CH4 at 298 K. Furthermore, Pb-TCPP shows electrocatalytic activity for water oxidation in alkaline solution. It is the first 3D porous Pb-MOF that exhibits both gas adsorption properties and electrocatalytic activity for an oxygen evolution reaction (OER).

  20. Solid-phase microcolumn extraction and gas chromatography-mass spectrometry identification of volatile organic compounds emitted by paper.

    Science.gov (United States)

    Hrivnák, Ján; Tölgyessy, Peter; Figedyová, Sona; Katuscák, Svetozár

    2009-11-15

    A rapid non-destructive sampling technique for the analysis of volatile organic compounds (VOCs) emitted by paper sheets is described. A capillary, which is connected to a microcolumn packed with Tenax TA, is inserted between two sheets at the centre of a paper stack encapsulated inside a PET/Al/PE composite foil. The other end of the microcolumn is connected to a gas-tight syringe and an appropriate volume of gaseous phase is aspirated. The microcolumn is then thermally desorbed in a modified GC inlet (modification is presented) and analysed by gas chromatography-mass spectrometry (GC-MS). In the chromatogram from the analysis of artificially aged paper sample 21 compounds were identified. Advantages of the method including the short sampling time (1 min), simplicity and economic aspect are discussed.

  1. Selective interfacial synthesis of metal-organic frameworks on a polybenzimidazole hollow fiber membrane for gas separation.

    Science.gov (United States)

    Biswal, Bishnu P; Bhaskar, Anand; Banerjee, Rahul; Kharul, Ulhas K

    2015-04-28

    Metal-organic frameworks (MOFs) have gained immense attention as new age materials due to their tuneable properties and diverse applicability. However, efforts on developing promising materials for membrane based gas separation, and control over the crystal growth positions on polymeric hollow fiber membranes still remain key challenges. In this investigation, a new, convenient and scalable room temperature interfacial method for growing MOFs (ZIF-8 and CuBTC) on either the outer or inner side of a polybenzimidazole based hollow fiber (PBI-BuI-HF) membrane surface has been achieved in a controlled manner. This was made possible by the appropriate selection of an immiscible solvent pair and the synthetic conditions. The growth of MOFs on the PBI-BuI-HF membrane by the interfacial method was continuous and showed an appreciable gas separation performance, conveying promise for their applicability.

  2. Use of manganese oxide and activated carbon fibers for removing a particle, volatile organic compound or ozone from a gas

    Science.gov (United States)

    Sidheswaran, Meera A.; Destaillats, Hugo; Fisk, William J.

    2016-08-30

    The present invention provides for a device for reducing a volatile organic compound (VOC) content of a gas comprising a manganese oxide (MnO.sub.x) catalyst. The manganese oxide (MnO.sub.x) catalyst is capable of catalyzing formaldehyde at room temperature, with complete conversion, to CO.sub.2 and water vapor. The manganese oxide (MnO.sub.x) catalyst itself is not consumed by the reaction of formaldehyde into CO.sub.2 and water vapor. The present invention also provides for a device for reducing or removing a particle, a VOC and/or ozone from a gas comprising an activated carbon filter (ACF) on a media that is capable of being periodically regenerated.

  3. Mitigation of greenhouse gas fluxes from cultivated organic soils by raised water table

    OpenAIRE

    Regina, Kristiina

    2010-01-01

    Cultivated organic soils are a remarkable source of greenhouse gases (GHG) in some countries and raised ground water table has been suggested as a mitigation measure on these soils. Drainage of the peat increases mineralization of the organic matter and causes high emissions of carbon dioxide (CO2) and nitrous oxide (N2O) while emissions of methane (CH4) are lowered compared to pristine peatlands. In countries with a large area of organic soils these GHG emissions can be remarkable. In ...

  4. EPA Method 525.3 - Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS)

    Science.gov (United States)

    Method 525.3 is an analytical method that uses solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) for the identification and quantitation of 125 selected semi-volatile organic chemicals in drinking water.

  5. Gas Chromatography and Mass Spectrometry Measurements and Protocols for Database and Library Development Relating to Organic Species in Support of the Mars Science Laboratory

    Science.gov (United States)

    Misra, P.; Garcia, R.; Mahaffy, P. R.

    2010-04-01

    An organic contaminant database and library has been developed for use with the Sample Analysis at Mars (SAM) instrumentation utilizing laboratory-based Gas Chromatography-Mass Spectrometry measurements of pyrolyzed and baked material samples.

  6. SEMICONDUCTOR DEVICES: Chlorine gas sensors using hybrid organic semiconductors of PANI/ZnPcCl16

    Science.gov (United States)

    Tingping, Lei; Yunbo, Shi; Wenlong, Lü; Yang, Liu; Wei, Tao; Pengliang, Yuan; Liwei, Lin; Daoheng, Sun; Liquan, Wang

    2010-08-01

    PANI/ZnPcCl16 (polyaniline doped with sulfosalicylic acid/hexadecachloro zinc phthalocyanine) powders were vacuum co-deposited onto Si substrates, where Pt interdigitated electrodes were made by micromachining. The PANI/ZnPcCl16 films were characterized and analyzed by SEM, and the influencing factors on its intrinsic performance were analyzed and sensitivities of the sensors were investigated by exposure to chlorine (Cl2) gas. The results showed that powders prepared with a stoichiometric ratio of (ZnPcCl16)0.6(PANI)0.4 had a preferential sensitivity to Cl2 gas, superior to those prepared otherwise; the optimal vacuum co-deposition conditions for the films are a substrate temperature of 160 °C, an evaporation temperature of 425 °C and a film thickness of 75 nm; elevating the operation temperature (above 100 °C) or increasing the gas concentration (over 100 ppm) would improve the response characteristics, but there should be upper levels for each. Finally, the gas sensing mechanism of PANI/ZnPcCl16 films was also discussed.

  7. Part-Load Performance of aWet Indirectly Fired Gas Turbine Integrated with an Organic Rankine Cycle Turbogenerator

    Directory of Open Access Journals (Sweden)

    Leonardo Pierobon

    2014-12-01

    Full Text Available Over the last years, much attention has been paid to the development of efficient and low-cost power systems for biomass-to-electricity conversion. This paper aims at investigating the design- and part-load performance of an innovative plant based on a wet indirectly fired gas turbine (WIFGT fueled by woodchips and an organic Rankine cycle (ORC turbogenerator. An exergy analysis is performed to identify the sources of inefficiencies, the optimal design variables, and the most suitable working fluid for the organic Rankine process. This step enables to parametrize the part-load model of the plant and to estimate its performance at different power outputs. The novel plant has a nominal power of 250 kW and a thermal efficiency of 43%. The major irreversibilities take place in the burner, recuperator, compressor and in the condenser. Toluene is the optimal working fluid for the organic Rankine engine. The part-load investigation indicates that the plant can operate at high efficiencies over a wide range of power outputs (50%–100%, with a peak thermal efficiency of 45% at around 80% load. While the ORC turbogenerator is responsible for the efficiency drop at low capacities, the off-design performance is governed by the efficiency characteristics of the compressor and turbine serving the gas turbine unit.

  8. Application of Homochiral Alkylated Organic Cages as Chiral Stationary Phases for Molecular Separations by Capillary Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Shengming Xie

    2016-11-01

    Full Text Available Molecular organic cage compounds have attracted considerable attention due to their potential applications in gas storage, catalysis, chemical sensing, molecular separations, etc. In this study, a homochiral pentyl cage compound was synthesized from a condensation reaction of (S,S-1,2-pentyl-1,2-diaminoethane and 1,3,5-triformylbenzene. The imine-linked pentyl cage diluted with a polysiloxane (OV-1701 was explored as a novel stationary phase for high-resolution gas chromatographic separation of organic compounds. Some positional isomers were baseline separated on the pentyl cage-coated capillary column. In particular, various types of enantiomers including chiral alcohols, esters, ethers and epoxides can be resolved without derivatization on the pentyl cage-coated capillary column. The reproducibility of the pentyl cage-coated capillary column for separation was investigated using nitrochlorobenzene and styrene oxide as analytes. The results indicate that the column has good stability and separation reproducibility after being repeatedly used. This work demonstrates that molecular organic cage compounds could become a novel class of chiral separation media in the near future.

  9. Application of Homochiral Alkylated Organic Cages as Chiral Stationary Phases for Molecular Separations by Capillary Gas Chromatography.

    Science.gov (United States)

    Xie, Shengming; Zhang, Junhui; Fu, Nan; Wang, Bangjin; Hu, Cong; Yuan, Liming

    2016-11-08

    Molecular organic cage compounds have attracted considerable attention due to their potential applications in gas storage, catalysis, chemical sensing, molecular separations, etc. In this study, a homochiral pentyl cage compound was synthesized from a condensation reaction of (S,S)-1,2-pentyl-1,2-diaminoethane and 1,3,5-triformylbenzene. The imine-linked pentyl cage diluted with a polysiloxane (OV-1701) was explored as a novel stationary phase for high-resolution gas chromatographic separation of organic compounds. Some positional isomers were baseline separated on the pentyl cage-coated capillary column. In particular, various types of enantiomers including chiral alcohols, esters, ethers and epoxides can be resolved without derivatization on the pentyl cage-coated capillary column. The reproducibility of the pentyl cage-coated capillary column for separation was investigated using nitrochlorobenzene and styrene oxide as analytes. The results indicate that the column has good stability and separation reproducibility after being repeatedly used. This work demonstrates that molecular organic cage compounds could become a novel class of chiral separation media in the near future.

  10. Energy resources' utilization in organic and conventional vineyards: Energy flow, greenhouse gas emissions and biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Kavargiris, Stefanos E.; Mamolos, Andreas P.; Nikolaidou, Anna E.; Kalburtji, Kiriaki L. [Laboratory of Ecology and Environmental Protection, Faculty of Agriculture, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece); Tsatsarelis, Constantinos A. [Laboratory of Agricultural Engineering, Faculty of Agriculture, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece)

    2009-09-15

    An energy analysis, in conventional and organic vineyards, combined with ethanol production and greenhouse gas emissions, is useful in evaluating present situation and deciding best management strategies. The objective of this study was to evaluate the differences in the energy flow between organic and conventional vineyards in three locations, to calculate CO{sub 2}, CH{sub 4} and N{sub 2}O-emissions based on the used fossil energy and to explore if wine industry wastes can be used to extract bioethanol. The data were collected through personal interviews with farmers during 2004-2005. Eighteen farmers, who owned vineyards about 1 ha each, were randomly selected to participate in this study [(3 conventional and 3 organic) x 3 locations]. The means averaged over all locations for fertilizer application, plant protection products application, transportation, harvesting, labor, machinery, fuels, plant protections products and tools energy inputs, total energy inputs, outputs (grapes), outputs (grapes + shoots), grape yield, man hour, pomace and ethanol from pomace were significantly higher in conventional than in organic vineyards, while the opposite occurred for the pruning. Means averaged over two farming systems for harvesting, tools energy inputs, energy outputs (grapes), grape yield, pomace and ethanol from pomace were significantly higher at location A, followed by location C and location B. Finally, for irrigation, the means averaged over the two farming systems were significantly lower at location C. Greenhouse gas emissions were significant lower in organic than in conventional vineyards. The results show a clear response of energy inputs to energy outputs that resulted from the farming system and location. (author)

  11. Thermodynamics of the sorption of organic compounds on polyethylene glycol 400-permethylated β-cyclodextrin stationary phase and its enantioselectivity in gas chromatography

    Science.gov (United States)

    Kuraeva, Yu. G.; Onuchak, L. A.; Evdokimova, M. A.

    2016-08-01

    The thermodynamic characteristics of sorption of 24 organic compounds of various classes from the gas phase on the binary stationary phase based on polyethylene glycol 400 and permethylated β-cyclodextrin were determined. The influence of geometrical structure and optical activity of organic compounds on the possibility of forming sorbate-macrocycle complexes was examined. It was found that the studied stationary phase shows the enantioselectivity towards low-polar terpenes under the conditions of gas chromatography.

  12. Variability analyses, site characterization, and regional [OH] estimates using trace gas measurements from the NOAA Global Greenhouse Gas Reference Network

    Directory of Open Access Journals (Sweden)

    Jan Pollmann

    2016-10-01

    Full Text Available Abstract Trace gas measurements from whole air samples collected weekly into glass flasks at background monitoring sites within the NOAA Global Greenhouse Gas Reference Network program (with most of the sites also being World Meteorological Organization (WMO Global Atmospheric Watch (GAW stations were used to investigate the variability-lifetime relationship for site characterization and to estimate regional and seasonal OH concentrations. Chemical species considered include the atmospheric trace gases CO, H2, and CH4, as well as the non-methane hydrocarbons (NMHC ethane (C2H6, propane (C3H8, i-butane (i-C4H10, and n-butane (n-C4H10. The correlation between atmospheric variability and lifetime was applied on a global scale spanning 42 sites with observations covering a period of 5 years. More than 50,000 individual flask measurement results were included in this analysis, making this the most extensive study of the variability-lifetime relationship to date. Regression variables calculated from the variability-lifetime relationship were used to assess the “remoteness” of sampling sites and to estimate the effect of local pollution on the measured distribution of atmospheric trace gases. It was found that this relationship yields reasonable results for description of the site remoteness and local pollution influences. Comparisons of seasonal calculated OH concentrations ([OH] from the variability-lifetime relationships with six direct station measurements yielded variable agreement, with deviations ranging from ∼20% to a factor of ∼2–3 for locations where [OH] monitoring results had been reported. [OH] calculated from the variability-lifetime relationships was also compared to outputs from a global atmospheric model. Resutls were highly variable, with approximately half of the sites yielding agreement to within a factor of 2–3, while others showed deviations of up to an order of magnitude, especially during winter.

  13. Regional crop productivity and greenhouse gas emissions from Swiss soils under organic farming

    Science.gov (United States)

    Lee, Juhwan; Necpalova, Magdalena; Six, Johan

    2016-04-01

    There is worldwide concern about the increase in atmospheric greenhouse gases (GHG) and their impact on climate change and food security. As a sustainable alternative, organic cropping in various forms has been promoted to minimize the environmental impacts of conventional practices. However, relatively little is known about the potential to reduce GHG emissions while maintaining crop productivity through the large-scale adoption of organic practices. Therefore, we simulated and compared regional crop production, soil organic carbon status, and net soil GHG emissions under organic and conventional practices. Grid-level (2.2 km by 2.2 km) simulation was performed using previously validated DailyDayCent by considering typical crop rotations. Regional model estimates are presented and discussed specifically with the focus on Swiss organic and conventional cropping systems, which differ by type and intensity of manuring, tillage, and cover crop.

  14. Laser Photolysis and Thermolysis of Organic Selenides and Tellurides for Chemical Gas-phase Deposition of Nanostructured Materials

    Directory of Open Access Journals (Sweden)

    Josef Pola

    2009-03-01

    Full Text Available Laser radiation-induced decomposition of gaseous organic selenides and tellurides resulting in chemical deposition of nanostructured materials on cold surfaces is reviewed with regard to the mechanism of the gas-phase decomposition and properties of the deposited materials. The laser photolysis and laser thermolysis of the Se and Te precursors leading to chalcogen deposition can also serve as a useful approach to nanostructured chalcogen composites and IVA group (Si, Ge, Sn element chalcogenides provided that it is carried out simultaneously with laser photolysis or thermolysis of polymer and IVA group element precursor.

  15. Laser photolysis and thermolysis of organic selenides and tellurides for chemical gas-phase deposition of nanostructured materials.

    Science.gov (United States)

    Pola, Josef; Ouchi, Akihiko

    2009-03-12

    Laser radiation-induced decomposition of gaseous organic selenides and tellurides resulting in chemical deposition of nanostructured materials on cold surfaces is reviewed with regard to the mechanism of the gas-phase decomposition and properties of the deposited materials. The laser photolysis and laser thermolysis of the Se and Te precursors leading to chalcogen deposition can also serve as a useful approach to nanostructured chalcogen composites and IVA group (Si, Ge, Sn) element chalcogenides provided that it is carried out simultaneously with laser photolysis or thermolysis of polymer and IVA group element precursor.

  16. Self-organization of hydrogen gas bubbles rising above laser-etched metallic aluminum in a weakly basic aqueous solution.

    Science.gov (United States)

    Barmina, E V; Kuzmin, P G; Shafeev, G A

    2011-10-01

    Self-organization of hydrogen bubbles is reported under etching of metallic Aluminum in a weakly basic solution. The ascending gas bubbles drift to the areas with higher density of bubbles. As a result, ascending bubbles form various stationary structures whose symmetry is determined by the symmetry of the etched area. Bubbles are aligned along the bisectors of the contour of the etched area. The special laser-assisted profiling of the etched area in shape of a vortex induces a torque in the fluid above the etched area. The process is interpreted on the basis of Bernoulli equation.

  17. Removal of halogenated organic compounds in landfill gas by top covers containing zero-valent iron

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Winther, K.; Kjeldsen, Peter

    2000-01-01

    Transformation of gaseous CCl3F and CCl4 by zero-valent iron was studied in systems unsaturated with water under anaerobic conditionssin an N2 gas and in a landfill gas atmosphere. The transformation was studied in batch as well as flow-through column tests. In both systems, the transformation...... process of the compounds was pseudo-firstorder. Transformation rate constants, referring to the water phase and normalized to 1 m2 iron surface/mL, of up to 1100 mL m-2 h-1 (batch) and 200 mL m-2 h-1 (flowthrough) were found. The transformation was strongly dependent on pH and the presence of oxygen....... During continuous aerobic conditions, the transformation of CCl3F decreased toward zero. Model calculations show that use of zero-valent iron in landfill top covers is a potential treatment technology for emission reduction of halogenated trace compounds from landfills....

  18. The identification of synthetic organic pigments in modern paints and modern paintings using pyrolysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Russell, Joanna; Singer, Brian W; Perry, Justin J; Bacon, Anne

    2011-05-01

    A collection of more than 70 synthetic organic pigments were analysed using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). We report on the analysis of diketo-pyrrolo-pyrrole, isoindolinone and perylene pigments which are classes not previously reported as being analysed by this technique. We also report on a number of azo pigments (2-naphthol, naphthol AS, arylide, diarylide, benzimidazolone and disazo condensation pigments) and phthalocyanine pigments, the Py-GC-MS analysis of which has not been previously reported. The members of each class were found to fragment in a consistent way and the pyrolysis products are reported. The technique was successfully applied to the analysis of paints used by the artist Francis Bacon (1909-1992), to simultaneously identify synthetic organic pigments and synthetic binding media in two samples of paint taken from Bacon's studio and micro-samples taken from three of his paintings and one painting attributed to him.

  19. Determination of the solubility of low volatility liquid organic compounds in water using volatile-tracer assisted headspace gas chromatography.

    Science.gov (United States)

    Zhang, Shu-Xin; Chai, Xin-Sheng; Barnes, Donald G

    2016-02-26

    This study reports a new headspace gas chromatographic method (HS-GC) for the determination of water solubility of low volatility liquid organic compounds (LVLOs). The HS-GC analysis was performed on a set of aqueous solutions containing a range of concentrations of toluene-spiked (as a tracer) LVLOs, from under-saturation to over-saturation. A plot of the toluene tracer GC signal vs. the concentration of the LVLO results in two lines of different slopes that intersect at the concentration corresponding to the compound's solubility in water. The results showed that the HS-GC method has good precision (RSD solubility of LVLOs at elevated temperatures. This approach should be of special interest to those concerned about the impact of the presence of low-volatility organic liquids in waters of environmental and biological systems.

  20. Landfill gas generation and emission at danish waste disposal sites receiving waste with a low organic waste content

    DEFF Research Database (Denmark)

    Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter

    2015-01-01

    two models are multi-phase models, which defines waste fractions into traditional MSW and low-organic waste categories, respectively. Both the LandGEM and the IPCC model estimated significantly larger methane (CH4) generation in comparison to the Afvalzorg model. The Afvalzorg model could better show...... the influence of not only the total disposed waste amount, but also various waste categories, and was found more suitable to estimate LFG generation from landfills receiving low-organic waste. Four major waste categories currently being disposed at Danish landfills (mixed bulky, shredder, dewatered sludge...... results. The LFG generation from four Danish landfills was estimated by the Afvalzorg model using the experimentally based BMP and k values and compared to whole landfill emission rates measured by applying a tracer gas dispersion method. The results showed that the revised modelled LFG generation rates...

  1. Spatiotemporal dynamics of phosphorus release, oxygen consumption and greenhouse gas emissions after localised soil amendment with organic fertilisers

    DEFF Research Database (Denmark)

    Christel, Wibke; Zhu, Kun; Hoefer, Christoph

    2016-01-01

    Organic fertilisation inevitably leads to heterogeneous distribution of organic matter and nutrients in soil, i.e. due to uneven surface spreading or inhomogeneous incorporation. The resulting localised hotspots of nutrient application will induce various biotic and abiotic nutrient turnover...... processes and fixation in the residue sphere, giving rise to distinct differences in nutrient availability, soil oxygen content and greenhouse gas (GHG) production. In this study we investigated the spatiotemporal dynamics of the reaction of manure solids and manure solids char with soil, focusing...... on their phosphorus (P) availability, as current emphasis on improving societal P efficiency through recycling waste or bio-based fertilisers necessitates a sound understanding of their behaviour. Soil layers amended at a constant P application rate with either pig manure solids or char made from pig manure solids...

  2. Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems

    Directory of Open Access Journals (Sweden)

    Franco Tassi

    2010-03-01

    Full Text Available The composition of non-methane organic volatile compounds (VOCs determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C2–C20 species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C4H8O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.

  3. Origin and distribution of thiophenes and furans in gas discharges from active volcanoes and geothermal systems.

    Science.gov (United States)

    Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

    2010-03-31

    The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C(2)-C(20) species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C(4)H(8)O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.

  4. New Pathways for the Formation of Complex Organics and Prebiotic Synthesis in the Gas Phase

    Science.gov (United States)

    El-Shall, M. S.

    2010-04-01

    We study the formation mechanisms of complex organics that are present in interstellar clouds. The reaction of acetylene ion with water produces vinyl alcohol while the reaction of benzene ion with acetylene produces naphthalene-type ion.

  5. Construction of a polyhedral metal-organic framework via a flexible octacarboxylate ligand for gas adsorption and separation.

    Science.gov (United States)

    Lin, Zu-Jin; Huang, Yuan-Biao; Liu, Tian-Fu; Li, Xiang-Ying; Cao, Rong

    2013-03-18

    A flexible octacarboxylate ligand, tetrakis[(3,5-dicarboxyphenyl)oxamethyl]methane (H8X), has been used to construct a highly porous metal-organic framework (In2X)(Me2NH2)2(DMF)9(H2O)5 (1), which is comprised of octahedral and cuboctahedral cages and shows a rare (4,8)-connected scu topology. Gas adsorption studies of N2, H2 on the actived 1 at 77 K reveal a Langmuir surface area of 1707 m(2) g(-1), a BET surface area of 1555 m(2) g(-1), a total pore volume of 0.62 cm(3) g(-1), and a H2 uptake of 1.49 wt % at 1 bar and 3.05 wt % at 16 bar. CO2, CH4, and N2 adsorption studies at 195, 273, 285, and 298 K and also ideal adsorbed solution theory (IAST) calculations demonstrate that 1 has high selectivites of CO2 over CH4 and N2. The resulting framework represents a MOF with the highest gas uptakes and gas selectivities (CO2 over CH4 and N2) constructed by flexible ligands.

  6. Impact of Marcellus Shale natural gas development in southwest Pennsylvania on volatile organic compound emissions and regional air quality.

    Science.gov (United States)

    Swarthout, Robert F; Russo, Rachel S; Zhou, Yong; Miller, Brandon M; Mitchell, Brittney; Horsman, Emily; Lipsky, Eric; McCabe, David C; Baum, Ellen; Sive, Barkley C

    2015-03-03

    The Marcellus Shale is the largest natural gas deposit in the U.S. and rapid development of this resource has raised concerns about regional air pollution. A field campaign was conducted in the southwestern Pennsylvania region of the Marcellus Shale to investigate the impact of unconventional natural gas (UNG) production operations on regional air quality. Whole air samples were collected throughout an 8050 km(2) grid surrounding Pittsburgh and analyzed for methane, carbon dioxide, and C1-C10 volatile organic compounds (VOCs). Elevated mixing ratios of methane and C2-C8 alkanes were observed in areas with the highest density of UNG wells. Source apportionment was used to identify characteristic emission ratios for UNG sources, and results indicated that UNG emissions were responsible for the majority of mixing ratios of C2-C8 alkanes, but accounted for a small proportion of alkene and aromatic compounds. The VOC emissions from UNG operations accounted for 17 ± 19% of the regional kinetic hydroxyl radical reactivity of nonbiogenic VOCs suggesting that natural gas emissions may affect compliance with federal ozone standards. A first approximation of methane emissions from the study area of 10.0 ± 5.2 kg s(-1) provides a baseline for determining the efficacy of regulatory emission control efforts.

  7. Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium

    Science.gov (United States)

    Iverach, Charlotte P.; Cendón, Dioni I.; Hankin, Stuart I.; Lowry, David; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.; Baker, Andy; Kelly, Bryce F. J.

    2015-11-01

    Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ13C-CH4), groundwater tritium (3H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ13C-CH4 versus CH4 concentration, in association with DOC concentration and 3H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity.

  8. Highly selective sieving of small gas molecules by using an ultra-microporous metal–organic framework membrane

    KAUST Repository

    Kang, Zixi

    2014-09-12

    © 2014 The Royal Society of Chemistry. Two tailor-made microporous metal-organic framework (MOF) membranes were successfully fabricated on nickel screens by secondary growth. The effect of pore structures on gas separation was examined by means of single and binary gas permeation tests. The MOF JUC-150 membrane with its ultra-micropores showed marked preferential permeance to H2 relative to other gas molecules. The selectivity factors of this membrane were 26.3, 17.1 and 38.7 for H2/CH4, H2/N2 and H2/CO2, respectively, at room temperature. To the best of our knowledge, these values represent unprecedentedly high separation selectivity among those for all MOF membranes reported to date. The JUC-150 membrane also shows high thermal stability and outstanding separation performance at a high temperature of 200 °C. The separation performance of these membranes persists even after more than 1 year exposure to air. The superiority of the tailored pore size, high selectivity for H2 over other gases, significant stability and recyclability make these materials potential candidates for industrial H2 recycling applications.

  9. Analysis and quantitation of volatile organic compounds emitted from plastics used in museum construction by evolved gas analysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Samide, Michael J; Smith, Gregory D

    2015-12-24

    Construction materials used in museums for the display, storage, and transportation of artwork must be assessed for their tendency to emit harmful pollution that could potentially damage cultural treasures. Traditionally, a subjective metals corrosion test known as the Oddy test has been widely utilized in museums for this purpose. To augment the Oddy test, an instrumental sampling approach based on evolved gas analysis (EGA) coupled to gas chromatography (GC) with mass spectral (MS) detection has been implemented for the first time to qualitatively identify off-gassed pollutants under specific conditions. This approach is compared to other instrumental methods reported in the literature. This novel application of the EGA sampling technique yields several benefits over traditional testing, including rapidity, high sensitivity, and broad detectability of volatile organic compounds (VOCs). Furthermore, unlike other reported instrumental approaches, the EGA method was used to determine quantitatively the amount of VOCs emitted by acetate resins and polyurethane foams under specific conditions using both an external calibration method as well as surrogate response factors. EGA was successfully employed to rapidly characterize emissions from 12 types of common plastics. This analysis is advocated as a rapid pre-screening method to rule out poorly performing materials prior to investing time and energy in Oddy testing. The approach is also useful for rapid, routine testing of construction materials previously vetted by traditional testing, but which may experience detrimental formulation changes over time. As an example, a case study on batch re-orders of rigid expanded poly(vinyl chloride) board stock is presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Characterization of Gas-Phase Organics Using Proton Transfer Reaction Time-of-Flight Mass Spectrometry: Aircraft Turbine Engines.

    Science.gov (United States)

    Kilic, Dogushan; Brem, Benjamin T; Klein, Felix; El-Haddad, Imad; Durdina, Lukas; Rindlisbacher, Theo; Setyan, Ari; Huang, Rujin; Wang, Jing; Slowik, Jay G; Baltensperger, Urs; Prevot, Andre S H

    2017-03-17

    Nonmethane organic gas emissions (NMOGs) from in-service aircraft turbine engines were investigated using a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) at an engine test facility at Zurich Airport, Switzerland. Experiments consisted of 60 exhaust samples for seven engine types (used in commercial aviation) from two manufacturers at thrust levels ranging from idle to takeoff. Emission indices (EIs) for more than 200 NMOGs were quantified, and the functional group fractions (including acids, carbonyls, aromatics, and aliphatics) were calculated to characterize the exhaust chemical composition at different engine operation modes. Total NMOG emissions were highest at idling with an average EI of 7.8 g/kg fuel and were a factor of ∼40 lower at takeoff thrust. The relative contribution of pure hydrocarbons (particularly aromatics and aliphatics) of the engine exhaust decreased with increasing thrust while the fraction of oxidized compounds, for example, acids and carbonyls increased. Exhaust chemical composition at idle was also affected by engine technology. Older engines emitted a higher fraction of nonoxidized NMOGs compared to newer ones. Idling conditions dominated ground level organic gas emissions. Based on the EI determined here, we estimate that reducing idle emissions could substantially improve air quality near airports.

  11. Secondary organic aerosol formation from the gas phase reaction of hydroxyl radicals with m-, o- and p-cresol

    Science.gov (United States)

    Henry, Françoise; Coeur-Tourneur, Cecile; Ledoux, Frédéric; Tomas, Alexandre; Menu, Dominique

    Secondary organic aerosol (SOA) formation during the atmospheric oxidation of cresols was investigated using a large smog chamber (8000 L), at atmospheric pressure, 294±2 K and low relative humidity (6-10%). Cresol oxidation was initiated by irradiation of cresol/CH 3ONO/NO/air mixtures. The cresol loss was measured by gas chromatography with a flame ionization detector (GC-FID) and the temporal evolution of the aerosol was monitored using a scanning mobility particle sizer (SMPS). The overall organic aerosol yield ( Y) was determined as the ratio of the suspended aerosol mass corrected for wall losses ( Mo) to the total reacted cresol concentrations assuming a particle density of 1.4 g cm -3. Analysis of the data clearly show that Y is a strong function of Mo and that SOA formation can be expressed by a one-product gas/particle partitioning absorption model. The aerosol formation is affected by the initial cresol concentration, which leads to aerosol yields from 9% to 42%. These results are in good agreement with a recent study performed on SOA formation from the photo-oxidation of o-cresol in a smog chamber. To our knowledge, the present work represents the first investigation of SOA formation from OH reaction with m- and p-cresol.

  12. Gas sensing performance of polyaniline/ZnO organic-inorganic hybrids for detecting VOCs at low temperature

    Institute of Scientific and Technical Information of China (English)

    Jing Huang; Taili Yang; Yanfei Kang; Yao Wang; Shurong Wang

    2011-01-01

    Polyaniline (PANI) was prepared by the chemical oxidative polymerization of aniline,and ZnO,with the mean particle size of 28 nm,was synthesized by a non-aqueous solvent method.The organic-inorganic PANI/ZnO hybrids with different mass fractions of PANI were obtained by mechanically mixing the prepared PANI and ZnO.The gas sensing properties of PANI/ZnO hybrids to different volatile organic compounds (VOCs) including methanol,ethanol and acetone were investigated at a low operating temperature of 90 ℃.Compared with the pure PANI and ZnO,the PANI/ZnO hybrids presented much higher response to VOCs.Meanwhile,the PANI/ZnO hybrid exhibited a good reversibility and a short response-recovery time,implying its potential application for gas sensors.The sensing mechanism was suggested to be related to the existence of p-n heterojunctions in the PANI/ZnO hybrids.

  13. Capture of nerve agents and mustard gas analogues by hydrophobic robust MOF-5 type metal-organic frameworks.

    Science.gov (United States)

    Montoro, Carmen; Linares, Fátima; Procopio, Elsa Quartapelle; Senkovska, Irena; Kaskel, Stefan; Galli, Simona; Masciocchi, Norberto; Barea, Elisa; Navarro, Jorge A R

    2011-08-10

    In this communication, a series of observations and data analyses coherently confirms the suitability of the novel metal-organic framework (MOF) [Zn(4)(μ(4)-O)(μ(4)-4-carboxy-3,5-dimethyl-4-carboxy-pyrazolato)(3)] (1) in the capture of harmful volatile organic compounds (VOCs). It is worthy of attention that 1, whose crystal structure resembles that of MOF-5, exhibits remarkable thermal, mechanical, and chemical stability, as required if practical applications are sought. In addition, it selectively captures harmful VOCs (including models of Sarin and mustard gas, which are chemical warfare agents), even in competition with ambient moisture (i.e., under conditions mimicking operative ones). The results can be rationalized on the basis of Henry constant and adsorption heat values for the different essayed adsorbates as well as H(2)O/VOC partition coefficients as obtained from variable-temperature reverse gas chromatography experiments. To further strengthen the importance of 1, its performance in the capture of harmful VOCs has been compared with those of well-known materials, namely, a MOF with coordinatively unsaturated metal sites, [Cu(3)(btc)(2)] and the molecular sieve active carbon Carboxen. The results of this comparison show that coordinatively unsaturated metal sites (preferential guest-binding sites) are ineffective for the capture of VOCs in the presence of ambient moisture. Consequently, we propose that the driving force of the VOC-MOF recognition process is mainly dictated by pore size and surface hydrophobicity. © 2011 American Chemical Society

  14. Economic assessment of greenhouse gas reduction through low-grade waste heat recovery using organic Rankine cycle (ORC)

    Energy Technology Data Exchange (ETDEWEB)

    Imran, Muhammad; Park, Byung Sik; Kim, Hyouck Ju; Usman, Muhammad [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Dong Hyun [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2015-02-15

    Low-grade waste heat recovery technologies reduce the environmental impact of fossil fuels and improve overall efficiency. This paper presents the economic assessment of greenhouse gas (GHG) reduction through waste heat recovery using organic Rankine cycle (ORC). The ORC engine is one of the mature low temperature heat engines. The low boiling temperature of organic working fluid enables ORC to recover low-temperature waste heat. The recovered waste heat is utilized to produce electricity and hot water. The GHG emissions for equivalent power and hot water from three fossil fuels-coal, natural gas, and diesel oil-are estimated using the fuel analysis approach and corresponding emission factors. The relative decrease in GHG emission is calculated using fossil fuels as the base case. The total cost of the ORC system is used to analyze the GHG reduction cost for each of the considered fossil fuels. A sensitivity analysis is also conducted to investigate the effect of the key parameter of the ORC system on the cost of GHG reduction. Throughout the 20-year life cycle of the ORC plant, the GHG reduction cost for R245fa is 0.02 $/kg to 0.04 $/kg and that for pentane is 0.04 $/kg to 0.05 $/kg. The working fluid, evaporation pressure, and pinch point temperature difference considerably affect the GHG emission.

  15. Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Hunkeler, Daniel

    2014-01-17

    An investigation was carried out to develop a simple and efficient method to collect vapour samples for compound specific isotope analysis (CSIA) by bubbling vapours through an organic solvent (methanol or ethanol). The compounds tested were benzene and trichloroethylene (TCE). The dissolution efficiency was tested for different air volume injections, using flow rates ranging from 25ml/min to 150ml/min and injection periods varying between 10 and 40min. Based on the results, complete mass recovery for benzene and TCE in both solvents was observed for the flow rates of 25 and 50ml/min. However, small mass loss was observed at increased flow rate. At 150ml/min, recovery was on average 80±17% for benzene and 84±10% for TCE, respectively in methanol and ethanol. The δ(13)C data measured for benzene and TCE dissolved in both solvents were reproducible and were stable independently of the volume of air injected (up to 6L) or the flow rate used. The stability of δ(13)C values hence underlines no isotopic fractionation due to compound-solvent interaction or mass loss. The development of a novel and simple field sampling technique undertaken in this study will facilitate the application of CSIA to diverse gas-phase volatile organic compound studies, such as atmospheric emissions, soil gas or vapour intrusion.

  16. Changes in concentration, composition and source contribution of atmospheric organic aerosols by shifting coal to natural gas in Urumqi

    Science.gov (United States)

    Ren, Yanqin; Wang, Gehui; Wu, Can; Wang, Jiayuan; Li, Jianjun; Zhang, Lu; Han, Yanni; Liu, Lang; Cao, Cong; Cao, Junji; He, Qing; Liu, Xinchun

    2017-01-01

    Size-segregated aerosols were collected in Urumqi, a megacity in northwest China, during two heating seasons, i.e., before (heating season І: January-March 2012) and after (heating season II: January-March 2014) the project "shifting coal to natural gas", and determined for n-alkanes, PAHs and oxygenated PAHs to investigate the impact of replacement of coal by natural gas on organic aerosols in the urban atmosphere. Our results showed that compared to those in heating season I concentrations of n-alkanes, PAHs and OPAHs decreased by 74%, 74% and 82% in heating season II, respectively. Source apportionment analysis suggested that coal combustion, traffic emission and biomass burning are the major sources of the determined organics during the heating seasons in Urumqi. Traffic emission is the main source for n-alkanes in the city. Coal combustion is the dominant source of PAHs and OPAHs in heating season І, but traffic emission becomes their major source in heating season ІI. Relative contributions of coal combustion to n-alkanes, PAHs and OPAHs in Urumqi decreased from 21 to 75% in heating season I to 4.0-21% in heating season II due to the replacement of coal with natural gas for house heating. Health risk assessment further indicated that compared with that in heating season I the number of lung cancer related to PAHs exposure in Urumqi decreased by 73% during heating season II due to the project implementation. Our results suggest that replacing coal by clean energy sources for house heating will significantly mitigate air pollution and improve human health in China.

  17. Depth resolution at organic interfaces sputtered by argon gas cluster ions: the effect of energy, angle and cluster size.

    Science.gov (United States)

    Seah, M P; Spencer, S J; Havelund, R; Gilmore, I S; Shard, A G

    2015-10-07

    An analysis is presented of the effect of experimental parameters such as energy, angle and cluster size on the depth resolution in depth profiling organic materials using Ar gas cluster ions. The first results are presented of the incident ion angle dependence of the depth resolution, obtained at the Irganox 1010 to silicon interface, from profiles by X-ray photoelectron spectrometry (XPS). By analysis of all relevant published depth profile data, it is shown that such data, from delta layers in secondary ion mass spectrometry (SIMS), correlate with the XPS data from interfaces if it is assumed that the monolayers of the Irganox 1010 adjacent to the wafer substrate surface have an enhanced sputtering rate. SIMS data confirm this enhancement. These results show that the traditional relation for the depth resolution, FWHM = 2.1Y(1/3) or slightly better, FWHM = P(X)Y(1/3)/n(0.2), where n is the argon gas cluster size, and P(X) is a parameter for each material are valid both at the 45° incidence angle of the argon gas cluster sputtering ions used in most studies and at all angles from 0° to 80°. This implies that, for optimal depth profile resolution, 0° or >75° incidence may be significantly better than the 45° traditionally used, especially for the low energy per atom settings required for the best resolved profiles in organic materials. A detailed analysis, however, shows that the FWHM requires a constant contribution added in quadrature to the above such that there are minimal improvements at 0° or greater than 75°. A critical test at 75° confirms the presence of this constant contribution.

  18. Composition of carbonaceous smoke particles from prescribed burning of a Canadian boreal forest: 1. Organic aerosol characterization by gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Mazurek, M.A.; Laterza, C.; Newman, L.; Daum, P. [Brookhaven National Lab., Upton, NY (United States); Cofer, W.R. III; Levine, J.S. [National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center; Winstead, E.L. [Science Applications International Corporation, Hampton, VA (United States)

    1995-06-01

    In this study we examine the molecular organic constituents (C8 to C40 lipid compounds) collected as smoke particles from a Canadian boreal forest prescribed burn. Of special interest are (1) the molecular identity of polar organic aerosols, and (2) the amount of polar organic matter relative to the total mass of aerosol particulate carbon. Organic extracts of smoke aerosol particles show complex distributions of the lipid compounds when analyzed by capillary gas chromatography/mass spectrometry. The molecular constituents present as smoke aerosol are grouped into non-polar (hydrocarbons) and polar {minus}2 oxygen atoms) subtractions. The dominant chemical species found in the boreal forest smoke aerosol are unaltered resin compounds (C20 terpenes) which are abundant in unburned conifer wood, plus thermally altered wood lignins and other polar aromatic hydrocarbons. Our results show that smoke aerosols contain molecular tracers which are related to the biofuel consumed. These smoke tracers can be related structurally back to the consumed softwood and hardwood vegetation. In addition, combustion of boreal forest materials produces smoke aerosol particles that are both oxygen-rich and chemically complex, yielding a carbonaceous aerosol matrix that is enriched in polar substances. As a consequence, emissions of carbonaceous smoke particles from large-scale combustion of boreal forest land may have a disproportionate effect on regional atmospheric chemistry and on cloud microphysical processes.

  19. Smart multi-channel two-dimensional micro-gas chromatography for rapid workplace hazardous volatile organic compounds measurement.

    Science.gov (United States)

    Liu, Jing; Seo, Jung Hwan; Li, Yubo; Chen, Di; Kurabayashi, Katsuo; Fan, Xudong

    2013-03-07

    We developed a novel smart multi-channel two-dimensional (2-D) micro-gas chromatography (μGC) architecture that shows promise to significantly improve 2-D μGC performance. In the smart μGC design, a non-destructive on-column gas detector and a flow routing system are installed between the first dimensional separation column and multiple second dimensional separation columns. The effluent from the first dimensional column is monitored in real-time and decision is then made to route the effluent to one of the second dimensional columns for further separation. As compared to the conventional 2-D μGC, the greatest benefit of the smart multi-channel 2-D μGC architecture is the enhanced separation capability of the second dimensional column and hence the overall 2-D GC performance. All the second dimensional columns are independent of each other, and their coating, length, flow rate and temperature can be customized for best separation results. In particular, there is no more constraint on the upper limit of the second dimensional column length and separation time in our architecture. Such flexibility is critical when long second dimensional separation is needed for optimal gas analysis. In addition, the smart μGC is advantageous in terms of elimination of the power intensive thermal modulator, higher peak amplitude enhancement, simplified 2-D chromatogram re-construction and potential scalability to higher dimensional separation. In this paper, we first constructed a complete smart 1 × 2 channel 2-D μGC system, along with an algorithm for automated control/operation of the system. We then characterized and optimized this μGC system, and finally employed it in two important applications that highlight its uniqueness and advantages, i.e., analysis of 31 workplace hazardous volatile organic compounds, and rapid detection and identification of target gas analytes from interference background.

  20. A thermodynamic tank model for studying the effect of higher hydrocarbons on natural gas storage in metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, HD; Deria, P; Farha, OK; Hupp, JT; Snurr, RQ

    2015-01-01

    Metal-organic frameworks (MOFs) are promising materials for storing natural gas in vehicular applications. Evaluation of these materials has focused on adsorption of pure methane, although commercial natural gas also contains small amounts of higher hydrocarbons such as ethane and propane, which adsorb more strongly than methane. There is, thus, a possibility that these higher hydrocarbons will accumulate in the MOF after multiple operating (adsorption/desorption) cycles, and reduce the storage capacity. To study the net effect of ethane and propane on the performance of an adsorbed natural gas (ANG) tank, we developed a mathematical model based on thermodynamics and mass balance equations that describes the state of the tank at any instant. The required inputs are the pure-component isotherms, and mixture adsorption data are calculated using the Ideal Adsorbed Solution Theory (IAST). We focused on how the "deliverable energy'' provided by the ANG tank to the engine changed over 200 operating cycles for a sample of 120 MOF structures. We found that, with any MOF, the ANG tank performance monotonically declines during early operating cycles until a "cyclic steady state'' is reached. We determined that the best materials when the fuel is 100% methane are not necessarily the best when the fuel includes ethane and propane. Among the materials tested, some top MOFs are MOF-143 > NU-800 > IRMOF-14 > IRMOF-20 > MIL-100 > NU-125 > IRMOF-1 > NU-111. MOF-143 is predicted to deliver 5.43 MJ L-1 of tank to the engine once the cyclic steady state is reached. The model also provided insights that can assist in future work to discover more promising adsorbent materials for natural gas storage.

  1. Solvothermal Metal Metathesis on a Metal-Organic Framework with Constricted Pores and the Study of Gas Separation.

    Science.gov (United States)

    Li, Liangjun; Xue, Haitao; Wang, Ying; Zhao, Pinhui; Zhu, Dandan; Jiang, Min; Zhao, Xuebo

    2015-11-18

    Metal-organic frameworks (MOFs) with constricted pores can increase the adsorbate density of gas and facilitate effective CO2 separation from flue gas or natural gas due to their enhanced overlapping of potential fields of the pores. Herein, an MOF with constricted pores, which was formed by narrow channels and blocks of functional groups, was fabricated from the assembly of a methyl-functionalized ligand and Zn(II) centers (termed NPC-7-Zn). Structural analysis of the as-synthesized NPC-7-Zn reveals a series of zigzag pores with pore diameters of ∼0.7 nm, which could be favorable for CO2 traps. For reinforcing the framework stability, a solvothermal metal metathesis on the pristine MOF NPC-7-Zn was performed, and a new Cu(II) MOF (termed NPC-7-Cu) with an identical framework was produced. The influence of the reaction temperatures on the metal metathesis process was investigated. The results show that the constricted pores in NPC-7-Zn can induce kinetic issues that largely slow the metal metathesis process at room temperature. However, this kinetic issue can be solved by applying higher reaction temperatures. The modified MOF NPC-7-Cu exhibits significant improvements in framework stability and thus leads to a permanent porosity for this framework. The constricted pore structure enables enhanced potential fields for these pores, rendering this MOF with high adsorbate densities for CO2 and high adsorption selectivity for a CO2/N2 gas mixture. The adsorption kinetic studies reveal that CH4 has a faster diffusion rate constant than CO2, showing a surface diffusion controlled mechanism for CO2 and CH4 adsorption.

  2. Windmill Co4 {Co4 (μ4 -O)} with 16 Divergent Branches Forming a Family of Metal-Organic Frameworks: Organic Metrics Control Topology, Gas Sorption, and Magnetism.

    Science.gov (United States)

    Chen, Qing; Xue, Wei; Lin, Jian-Bin; Wei, Yong-Sheng; Yin, Zheng; Zeng, Ming-Hua; Kurmoo, Mohamedally; Chen, Xiao-Ming

    2016-08-16

    A series of highly connected metal-organic frameworks (MOFs), [Co8 (O)(OH)4 (H2 O)4 (ina)8 ](NO3 )2 ⋅2 C2 H5 OH⋅4 H2 O (1), [Co8 (O)(OH)4 (H2 O)4 (pba)8 ](NO3 )2 ⋅8 C2 H5 OH⋅28 H2 O (2), and [Co8 (O)(OH)4 (H2 O)4 (pbba)8 ](NO3 )2 ⋅guest (3), in which ina=isonicotinate, pba=4-pyridylbenzoate, and pbba=4-(pyridine-4-yl)phenylbenzoate, is reported. These MOFs contain a new secondary building unit (SBU), with a square Co4 (μ4 -O) central unit having the rare μ4 -O(2-) motif, which is decorated by the other four peripheral cobalt atoms through μ3 -OH in a windmill-like shape. This SBU holds 16 divergent connecting organic ligands, pyridyl-carboxylates, to form three different frameworks. The high porosity of desolvated 2 is shown by the efficient gas absorption of N2 , CO2 , CH4 , and H2 . In addition, 1 and 2 exhibit unusual canted antiferromagnetic behavior with spin-glass-like relaxation, with blocking temperatures that are fairly high, 20 K (1) and 10 K (2), for cobalt materials. The relationship between the metal clusters and linkers has been studied, in which the size and rotational degrees of freedom of the ligands are found to control the topology, gas sorption, and magnetic properties.

  3. SCREENING PROCESSED MILK FOR VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION/GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    Science.gov (United States)

    An adaptation of Office of Solid Waste and Emergency Response' Test Methods for Evaluating Solid Waste Physical/Chemical Methods (SW-846) method 8261 to analyze milk for an expanded list of volatile organic compounds is presented. The milk matriz exhibits a strong affinity for o...

  4. Thin Film Organic / Inorganic Multilayer Gas Barriers by Hot-Wire and Initiated CVD

    NARCIS (Netherlands)

    Spee, D.A.

    2013-01-01

    A very attractive property for many optoelectronic devices, such as solar cells and organic light emitting diodes (OLEDs), is light weight and mechanical flexibility. This will open new technological opportunities, such as thin flexible lighting, lightweight conformable solar cells, and rollable dis

  5. Gas Phase Sensing of Alcohols by Metal Organic Framework-Polymer Composite Materials

    NARCIS (Netherlands)

    Sachdeva, Sumit; Koper, Sander J.H.; Sabetghadam, Anahid; Soccol, Dimitri; Gravesteijn, Dirk J.; Kapteijn, Freek; Sudhölter, Ernst J.R.; Gascon, Jorge; Smet, De Louis C.P.M.

    2017-01-01

    Affinity layers play a crucial role in chemical sensors for the selective and sensitive detection of analytes. Here, we report the use of composite affinity layers containing Metal Organic Frameworks (MOFs) in a polymeric matrix for sensing purposes. Nanoparticles of NH2-MIL-53(Al) were dispersed in

  6. Primary gas- and particle-phase emissions and secondary organic aerosol production from gasoline and diesel off-road engines.

    Science.gov (United States)

    Gordon, Timothy D; Tkacik, Daniel S; Presto, Albert A; Zhang, Mang; Jathar, Shantanu H; Nguyen, Ngoc T; Massetti, John; Truong, Tin; Cicero-Fernandez, Pablo; Maddox, Christine; Rieger, Paul; Chattopadhyay, Sulekha; Maldonado, Hector; Maricq, M Matti; Robinson, Allen L

    2013-12-17

    Dilution and smog chamber experiments were performed to characterize the primary emissions and secondary organic aerosol (SOA) formation from gasoline and diesel small off-road engines (SOREs). These engines are high emitters of primary gas- and particle-phase pollutants relative to their fuel consumption. Two- and 4-stroke gasoline SOREs emit much more (up to 3 orders of magnitude more) nonmethane organic gases (NMOGs), primary PM and organic carbon than newer on-road gasoline vehicles (per kg of fuel burned). The primary emissions from a diesel transportation refrigeration unit were similar to those of older, uncontrolled diesel engines used in on-road vehicles (e.g., premodel year 2007 heavy-duty diesel trucks). Two-strokes emitted the largest fractional (and absolute) amount of SOA precursors compared to diesel and 4-stroke gasoline SOREs; however, 35-80% of the NMOG emissions from the engines could not be speciated using traditional gas chromatography or high-performance liquid chromatography. After 3 h of photo-oxidation in a smog chamber, dilute emissions from both 2- and 4-stroke gasoline SOREs produced large amounts of semivolatile SOA. The effective SOA yield (defined as the ratio of SOA mass to estimated mass of reacted precursors) was 2-4% for 2- and 4-stroke SOREs, which is comparable to yields from dilute exhaust from older passenger cars and unburned gasoline. This suggests that much of the SOA production was due to unburned fuel and/or lubrication oil. The total PM contribution of different mobile source categories to the ambient PM burden was calculated by combining primary emission, SOA production and fuel consumption data. Relative to their fuel consumption, SOREs are disproportionately high total PM sources; however, the vastly greater fuel consumption of on-road vehicles renders them (on-road vehicles) the dominant mobile source of ambient PM in the Los Angeles area.

  7. Multi-generation gas-phase oxidation, equilibrium partitioning, and the formation and evolution of secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2012-01-01

    Full Text Available A new statistical model of secondary organic aerosol (SOA formation is developed that explicitly takes into account multi-generational oxidation as well as fragmentation of gas-phase compounds. The model framework requires three tunable parameters to describe the kinetic evolution of SOA mass, the average oxygen-to-carbon atomic ratio and the mean particle volatility as oxidation proceeds. These parameters describe (1 the relationship between oxygen content and volatility, (2 the probability of fragmentation and (3 the amount of oxygen added per reaction. The time-evolution and absolute value of the SOA mass depends sensitively on all three tunable parameters. Of the tunable parameters, the mean O:C is most sensitive to the oxygen/volatility relationship, exhibiting only a weak dependence on the other two. The mean particle O:C produced from a given compound is primarily controlled by the number of carbon atoms comprising the SOA precursor. It is found that gas-phase compounds with larger than 11 carbon atoms are unlikely to form SOA with O:C values >0.4, which suggests that so-called "intermediate-volatility" organic compounds (IVOCs and "semi-volatile" organic compounds (SVOCs are not major contributors to the ambient SOA burden when high O:C ratios are observed, especially at short atmospheric times. The model is tested against laboratory measurements of SOA formation from the photooxidation of α-pinene and n-pentadecane and performs well (after tuning. This model may provide a generalized framework for the interpretation of laboratory SOA formation experiments in which explicit consideration of multiple-generations of products is required, which is true for all photo-oxidation experiments.

  8. The Tropical Forest and Fire Emissions Experiment: method evaluation of volatile organic compound emissions measured by PTR-MS, FTIR, and GC from tropical biomass burning

    Directory of Open Access Journals (Sweden)

    T. G. Karl

    2007-11-01

    Full Text Available Volatile Organic Compound (VOC emissions from fires in tropical forest fuels were quantified using Proton-Transfer-Reaction Mass Spectrometry (PTRMS, Fourier Transform Infrared Spectroscopy (FTIR and gas chromatography (GC coupled to PTRMS (GC-PTR-MS. We investigated VOC emissions from 19 controlled laboratory fires at the USFS (United States Forest Service Fire Sciences Laboratory and 16 fires during an intensive airborne field campaign during the peak of the burning season in Brazil in 2004. The VOC emissions were dominated by oxygenated VOCs (OVOC (OVOC/NMHC ~4:1, NMHC: non-methane hydrocarbons The specificity of the PTR-MS instrument, which measures the mass to charge ratio of VOCs ionized by H3O+ ions, was validated by gas chromatography and by intercomparing in-situ measurements with those obtained from an open path FTIR instrument. Emission ratios for methyl vinyl ketone, methacrolein, crotonaldehyde, acrylonitrile and pyrrole were measured in the field for the first time. Our measurements show a higher contribution of OVOCs than previously assumed for modeling purposes. Comparison of fresh (<15 min and aged (>1 h–1 d smoke suggests altered emission ratios due to gas phase chemistry for acetone but not for acetaldehyde and methanol. Emission ratios for numerous, important, reactive VOCs with respect to acetonitrile (a biomass burning tracer are presented.

  9. A micro gas chromatography column with a micro thermal conductivity detector for volatile organic compound analysis.

    Science.gov (United States)

    Sun, J H; Cui, D F; Chen, X; Zhang, L L; Cai, H Y; Li, H

    2013-02-01

    In this paper, a micro gas chromatography (μGC) system contained a μGC column and a micro thermal conductivity detector (μTCD) was proposed. In order to reduce the volume of the system, some micro heaters were integrated on the surface and backside of the GC column, which could provide a robust temperature programming capability and rapidly increase the temperature of the μGC column. In addition, a silicon-glass μTCD with four-thermistor thermal conductivity cells that can offer significant advantages over previously reported designs including low dead volume, good thermal isolation, and elimination of the thermal noise was proposed in this paper. Experimental results have indicated that the μGC system with a detection limit of several ppm concentration levels separated and detected the benzene, toluene, and styrene in less than 3 min, and the μGC system also exhibited a good linear response in the test range.

  10. Organic iodine removal from simulated dissolver off-gas streams using partially exchanged silver mordenite

    Energy Technology Data Exchange (ETDEWEB)

    Jubin, R.T.

    1982-01-01

    The removal of methyl iodide by adsorption onto silver mordenite was studied using a simulated off-gas from the fuel dissolution step of a nuclear fuel reprocessing plant. The methyl iodide adsorption of partially exchanged silver mordenite was examined for the effects of NO/sub x/, humidity, filter temperature, and degree of silver exchange. Partially exchanged silver mordenite, in general, achieved significantly higher silver utilizations than the fully exchanged material. Silver utilizations of > 95% were achieved, assuming the formation of AgI. The experimental results indicate that CH/sub 3/I loadings increase proportionally with silver loading up to 5 wt % silver and then appear to level off. Tests conducted to determine the effect of temperature on the loading showed higher loadings at 200/sup 0/C than at either 150 or 250/sup 0/C. The presence of NO, NO/sub 2/, and H/sub 2/O vapor showed negligible effects on the loading of CH/sub 3/I. In contrast to iodine loaded onto fully exchanged silver mordenite, the iodine loaded onto the partially exchanged silver mordenite could not be stripped by either 4.5% hydrogen or 100% hydrogen at temperatures up to 500/sup 0/C. A study of the regeneration characteristics of fully exchanged silver mordenite indicates a decreased adsorbent capacity after complete removal of the iodine with 4.5% hydrogen in the regeneration gas stream at 500/sup 0/C. The loss of adsorbent capacity was much higher for silver mordenite regenerated in a stainless steel filter housing than in a glass filter housing. A cost evaluation for the use of the partially exchanged silver mordenite shows that the cost of the silver mordenite on a once-through basis is < $10/h of operation for a 0.5-t/d reprocessing plant.

  11. Application of gas chromatography analysis to quality control of residual organic solvents in clopidogrel bisulphate

    Directory of Open Access Journals (Sweden)

    Pavlović Aleksandar D.

    2014-01-01

    Full Text Available A direct-injection, split-mode capillary gas chromatographic procedure with a flame ionization detection is developed for the analysis of eight solvents used in the synthesis and purification of an anti-thrombotic drug clopidogrel bisulphate. The solvents analyzed were methanol, acetone, dichloromethane (DCM, 2-butanol, cyclohexane, toluene, acetic acid and N, N-dimethyl formamide (DMF. In addition, as a result of dehydration of 2-butanol during drying process, in clopidogrel bisulphate samples, significant amounts of 2-butanol dehydration products (1-butene, cis and trans isomers of 2-butene, 2,2'-oxydibutane and 1-(1-methylpropoxybutane may be detected. The content of each of these volatile products can be evaluated using the same gas-chromatographic method, with quantification based on the response factor established for the chromatographic peak of 2-butanol. For each solvent used in the process of clopidogrel bisulphate preparation, the procedure is validated for selectivity, linearity, recovery, precision, robustness, quantitation limit, and detection limit. All eight solvents plus five 2-butanol degradation products are fully separated. System suitability test is validated, and requirements are set. Based on a large number of result sets, retrospectively, from many different batches analyzed, conclusions were made about process variations and reliability and a lack of consistency was identified in the quality of the active substance from a particular producer source. Multivariate analysis was used as statistical technique to classify samples. From the analyzed set of 11 solvents, 6 of them were preselected based upon their occurrence in the samples and both Principal Component Analysis (PCA and Hierarchical Cluster Analysis (HCA were performed.

  12. Characterization of soil organic matter with different degrees of humification using evolved gas analysis-mass spectrometry.

    Science.gov (United States)

    Katsumi, Naoya; Yonebayashi, Koyo; Okazaki, Masanori; Nishiyama, Shun; Nishi, Tomoe; Hosaka, Akihiko; Watanabe, Chuichi

    2016-08-01

    Evolved gas analysis-mass spectrometry (EGA-MS) provides a direct connection between the pyrolyzer and mass spectrometer through a deactivated capillary tube, and provides both a thermal profile relating to the differential thermogravimetric curve of the sample and a mass spectrum of evolved gas from the sample. In this study, EGA-MS was performed to obtain thermal profiles and identify the pyrolysis products of 12 humic acids (HAs) with different degrees of humification extracted from 5 Andisols, 3 Entisols, and 3 Inceptisols, as well as soil samples. All HAs were thermally decomposed gradually over a wide temperature range (100-700°C), and the EGA curves showed four peaks and shoulders at around 250, 350, 450, and 550°C. The peaks at around 550°C were observed for the Andisol HAs only. Carboxyl groups, carbohydrates, and short chain alkanes and alkenes of the HAs and bulk soil samples evolved at a relatively low-temperature region (200-300°C). On the other hand, aromatics including benzenes and lignin derivatives evolved at a relatively high-temperature region (300-600°C). While the shapes of the EGA curves were different between the soils and extracted HAs, the major components of the evolved gas and the pyrolysis behavior of the constituents in the HAs and soil samples were similar. The amount of evolved gas from the Andisol HAs, which mainly consisted of CO2, was very low in comparison to that from the Entisol and Inceptisol HAs. The amount of evolved gas and the molecular weight of the pyrolysis products decreased as humification progressed, but the proportion of CO2 in the total area of the EGA curves increased. The results demonstrated that humification reduces the proportion of volatile components and increases the amount of carboxyl groups. As a result, the molecular structure of HAs is found to be mainly composed of non-volatile components and carboxyl groups. Since EGA-MS can provide information about the chemical structure and pyrolysis

  13. Specific analysis of trace organics in water using gas chromatography and mass spectroscopy.

    Science.gov (United States)

    Reinhard, M; Schreiner, J E; Everhart, T; Graydon, J

    1987-01-01

    For the characterization of a broad range of compounds in water, various methods have been combined into a procedure. The reliability and limitations of this approach have been discussed in this paper. This combined procedure represents only a preliminary solution to the problem of organic materials in water. Future improvements will be possible as new columns, instruments, and software become available. Physico-chemical constants of trace organic compounds have been used to predict and interpret their extraction and pre-separation in an analytical scheme where purge/trap and solvent extraction methods are combined to measure a broad range of organic materials. This approach is limited by the scarcity of thermodynamic data; such data must be generated if predictive models of pollutant behavior in analytical as well as environmental systems are to be developed. In summary, the basic requirements for analyzing trace organic compounds in tertiary effluents and drinking waters include: The analysis must be based on a small sample size (up to 1 liter). Samples of one gallon or more are costly to ship and difficult to process and store. Samples of one liter or less can be shipped at moderate cost and stored in medium-sized refrigerators. The detection limit for most trace contaminants must be in the lower nanogram per liter range. At detection limits of 1 microgram/l and above, the removal (or formation) of many contaminants cannot be determined precisely. For conclusive results, variabilities of the procedure, the compound, and concentration at a sampling point have to be considered and investigated. Generally, approximately 30 samples are needed to establish a concentration distribution (1).

  14. Aging of biogenic secondary organic aerosol via gas-phase OH radical reactions

    DEFF Research Database (Denmark)

    Donahue, Neil M.; Henry, Kaytlin M.; Mentel, Thomas F.;

    2012-01-01

    The Multiple Chamber Aerosol Chemical Aging Study (MUCHACHAS) tested the hypothesis that hydroxyl radical (OH) aging significantly increases the concentration of first-generation biogenic secondary organic aerosol (SOA). OH is the dominant atmospheric oxidant, and MUCHACHAS employed environmental...... with an existing gap between global SOA sources and those predicted in models, and can be described by a mechanism suitable for implementation in those models....

  15. Synthesis and gas adsorption properties of tetra-armed microporous organic polymer networks based on triphenylamine.

    Science.gov (United States)

    Yang, Xiao; Yao, Shuwen; Yu, Miao; Jiang, Jia-Xing

    2014-04-01

    Two novel tetra-armed microporous organic polymers have been designed and synthesized via a nickel-catalyzed Yamamoto-type Ullmann cross-coupling reaction or Suzuki cross-coupling polycondensation. These polymers are stable in various solvents, including concentrated hydrochloric acid, and are thermally stable. The homocoupled polymer YPTPA shows much higher Brunauer-Emmet-Teller-specific surface area up to 1557 m(2) g(-1) than the copolymer SPTPA (544 m(2) g(-1)), and a high CO2 uptake ability of 3.03 mmol g(-1) (1.13 bar/273 K) with a CO2 /N2 sorption selectivity of 17.3:1. Both polymers show high isosteric heats of CO2 adsorption (22.7-26.5 kJ mol(-1)) because the incorporation of nitrogen atoms into the skeleton of microporous organic polymers enhances the interaction between the pore wall and the CO2 molecules. The values are higher than those of the porous aromatic frameworks, which contain neither additional polar functional groups nor nitrogen atoms, and are rather close to those of previously reported microporous organic polymers containing the nitrogen atoms on the pore wall. These data show that these materials would be potential candidates for applications in post-combustion CO2 capture and sequestration technology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A Comparative Exergoeconomic Analysis of Waste Heat Recovery from a Gas Turbine-Modular Helium Reactor via Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Naser Shokati

    2014-04-01

    Full Text Available A comparative exergoeconomic analysis is reported for waste heat recovery from a gas turbine-modular helium reactor (GT-MHR using various configurations of organic Rankine cycles (ORCs for generating electricity. The ORC configurations studied are: a simple organic Rankine cycle (SORC, an ORC with an internal heat exchanger (HORC and a regenerative organic Rankine cycle (RORC. Exergoeconomic analyses are performed with the specific exergy costing (SPECO method. First, energy and exergy analyses are applied to the combined cycles. Then, a cost-balance, as well as auxiliary equations are developed for the components to determine the exergoeconomic parameters for the combined cycles and their components. The three combined cycles are compared considering the same operating conditions for the GT-MHR cycle, and a parametric study is done to reveal the effects on the exergoeconomic performance of the combined cycles of various significant parameters, e.g., turbine inlet and evaporator temperatures and compressor pressure ratio. The results show that the GT-MHR/RORC has the lowest unit cost of electricity generated by the ORC turbine. This value is highest for the GT-MHR/HORC. Furthermore, the GT-MHR/RORC has the highest and the GT-MHR/HORC has the lowest exergy destruction cost rate.

  17. Analytical Approaches Based on Gas Chromatography Mass Spectrometry (GC/MS) to Study Organic Materials in Artworks and Archaeological Objects.

    Science.gov (United States)

    Bonaduce, Ilaria; Ribechini, Erika; Modugno, Francesca; Colombini, Maria Perla

    2016-02-01

    Gas chromatography/mass spectrometry (GC/MS), after appropriate wet chemical sample pre-treatments or pyrolysis, is one of the most commonly adopted analytical techniques in the study of organic materials from cultural heritage objects. Organic materials in archaeological contexts, in classical art objects, or in modern and contemporary works of art may be the same or belong to the same classes, but can also vary considerably, often presenting different ageing pathways and chemical environments. This paper provides an overview of the literature published in the last 10 years on the research based on the use of GC/MS for the analysis of organic materials in artworks and archaeological objects. The latest progresses in advancing analytical approaches, characterising materials and understanding their degradation, and developing methods for monitoring their stability are discussed. Case studies from the literature are presented to examine how the choice of the working conditions and the analytical approaches is driven by the analytical and technical question to be answered, as well as the nature of the object from which the samples are collected.

  18. Earthworms change the quantity and composition of dissolved organic carbon and reduce greenhouse gas emissions during composting

    DEFF Research Database (Denmark)

    Nigatu, Abebe Nigussie; Bruun, Sander; de Neergaard, Andreas

    2017-01-01

    Dissolved organic carbon (DOC) has recently been proposed as an indicator of compost stability. We assessed the earthworms' effect on DOC content and composition during composting, and linked compost stability to greenhouse gas emissions and feeding ratio. Earthworms reduced total DOC content......, indicating larger stability of vermicompost than of thermophilic compost. The concentrations of humic acid and fulvic acid were reduced by earthworms, whereas there was no significant effect on hydrophobic neutrals and hydrophilics. The humic acid fraction was depleted more quickly than the other compounds......, indicating humic acid degradation during composting. The optimum feeding ratio decreased DOC content compared to the high feeding ratio. The lowest N2O emissions were also observed at the optimum feeding ratio. Our study confirmed the use of DOC content and composition as an indicator of compost stability...

  19. Development of organic waste gas treatment%有机废气生物处理进展

    Institute of Scientific and Technical Information of China (English)

    汪印; 魏广业; 史长东; 鲁树成

    2001-01-01

    The process and the principle of the bio-filter, bio-trickling reactor and bio-washing reactor, which are three major types of bio-treatment of organic waste gas, are summarized. The development trend and application prospect is also discussed. The kinetic models of bio-filter and bio-trickling reactor are given.%概述了有机废气生物处理的三种主要形式-生物滤池、生物滴滤塔和生物洗涤器处理有机废气的流程、原理等,讨论了其发展趋势及应用前景,给出了生物滤池和生物滴滤塔的动力学模型.

  20. Use of the PIXEL method to investigate gas adsorption in metal-organic frameworks.

    Science.gov (United States)

    Maloney, Andrew G P; Wood, Peter A; Parsons, Simon

    2016-05-14

    PIXEL has been used to perform calculations of adsorbate-adsorbent interaction energies between a range of metal-organic frameworks (MOFs) and simple guest molecules. Interactions have been calculated for adsorption between MOF-5 and Ar, H2, and N2; Zn2(BDC)2(TED) (BDC = 1,4-benzenedicarboxylic acid, TED = triethylenediamine) and H2; and HKUST-1 and CO2. The locations of the adsorption sites and the calculated energies, which show differences in the Coulombic or dispersion characteristic of the interaction, compare favourably to experimental data and literature energy values calculated using density functional theory.

  1. Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

    Science.gov (United States)

    Hinckley, D.A.; Bidleman, T.F.; Foreman, W.T.; Tuschall, J.R.

    1990-01-01

    Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

  2. An investigation into the use of novel organic materials in gas sensor devices

    CERN Document Server

    Bates, J

    1993-01-01

    oxidised it to the lower conductivity (10 sup - sup 3 S/cm) neutral (Ni(dmit) sub 2) species; the SO sub 2 was presumed to act upon the mixed valence phase and reduce it to the lower conductivity (10 sup - sup 3 S/cm) monoanion species. In order to identify the species responsible for the gas sensitivity various analytical techniques were used including X-Ray diffraction, C,H,N,S analysis, scanning electron microscopy and cyclic voltammetry experiments. The SEM studies showed the effect of solvent composition on the film morphology and indicated that the films were of a highly crystalline nature and this was confirmed by X-Ray diffraction. Single crystal analysis showed the species deposited on platinum wire electrodes at 1.1 V/SCE was the neutral Ni(dmit) sub 2 species. C,H,N,S analysis suggested the films were primarily the neutral Ni(dmit) sub 2 species with a small amount of the mixed valence phase present. Cyclic voltammetry experiments enabled identification of the various electrochemical processes invo...

  3. Characterization of phenol and alkyl phenols in organic matrixes with monoethylene glycol extraction and multidimensional gas chromatography/mass spectrometry.

    Science.gov (United States)

    Luong, J; Gras, R; Cortes, H J; Shellie, R A

    2013-07-02

    The use of monoethylene glycol as an extraction medium for removing phenol and alkyl phenols in organic matrixes such as hydrocarbons is introduced and combined with a practical analytical multidimensional gas chromatography approach. The analytical approach has been successfully developed for the characterization of phenol, cresols, xylenols, and alkyl phenols like 4-ethylphenol and 2,3,5-trimethylphenol. The technique employs a single-step extraction of the analytes with monoethylene glycol and sonication, followed by multidimensional gas chromatography with mass spectrometry in selected ion monitoring mode for the detection and quantitation. Extraction efficiency of phenol approached 100% while cresols, xylenols, and 4-ethylphenol were 97% or higher and 2,3,5-trimethylphenol was better than 91% under the analytical conditions used. With the technique described, a complete analysis can be conducted in less than 16 min. Reproducibility of area counts at two levels, namely, 5 ppm(w) and 50 ppm(w) over a period of 2 days were found to be less than 4% (n = 20). The analytes of interest was found to be linear over a range from 100 ppb(w) to 250 ppm(w) with correlation coefficient of at least 0.999 and detection limit of 50 ppb(w) . Spike recoveries from 500 ppb(w) to 250 ppm(w) for all analytes range from 96 to 102%.

  4. Characterization of Gas-Phase Organics Using Proton Transfer Reaction Time-of-Flight Mass Spectrometry: Cooking Emissions.

    Science.gov (United States)

    Klein, Felix; Platt, Stephen M; Farren, Naomi J; Detournay, Anais; Bruns, Emily A; Bozzetti, Carlo; Daellenbach, Kaspar R; Kilic, Dogushan; Kumar, Nivedita K; Pieber, Simone M; Slowik, Jay G; Temime-Roussel, Brice; Marchand, Nicolas; Hamilton, Jacqueline F; Baltensperger, Urs; Prévôt, André S H; El Haddad, Imad

    2016-02-02

    Cooking processes produce gaseous and particle emissions that are potentially deleterious to human health. Using a highly controlled experimental setup involving a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), we investigate the emission factors and the detailed chemical composition of gas phase emissions from a broad variety of cooking styles and techniques. A total of 95 experiments were conducted to characterize nonmethane organic gas (NMOG) emissions from boiling, charbroiling, shallow frying, and deep frying of various vegetables and meats, as well as emissions from vegetable oils heated to different temperatures. Emissions from boiling vegetables are dominated by methanol. Significant amounts of dimethyl sulfide are emitted from cruciferous vegetables. Emissions from shallow frying, deep frying and charbroiling are dominated by aldehydes of differing relative composition depending on the oil used. We show that the emission factors of some aldehydes are particularly large which may result in considerable negative impacts on human health in indoor environments. The suitability of some of the aldehydes as tracers for the identification of cooking emissions in ambient air is discussed.

  5. Porous anionic indium-organic framework with enhanced gas and vapor adsorption and separation ability.

    Science.gov (United States)

    Huang, Yuanbiao; Lin, Zujin; Fu, Hongru; Wang, Fei; Shen, Min; Wang, Xusheng; Cao, Rong

    2014-09-01

    A three-dimensional microporous anionic metal-organic framework (MOF) (Et4N)3[In3(TATB)4] (FJI-C1, H3TATB=4,4',4''-s-triazine-2,4,6-triyltribenzoic acid) with large unit cell volume has been synthesized. Assisted by the organic cation group Et4N in the pores of the compound, FJI-C1 not only shows high adsorption uptakes of C2 and C3 hydrocarbons, but also exhibits highly selective separation of propane, acetylene, ethane, and ethylene from methane at room temperature. Furthermore, it also exhibits high separation selectivity for propane over C2 hydrocarbons and acetylene can be readily separated from their C2 hydrocarbons mixtures at low pressure due to the high selectivity for C2H2 in comparison to C2H4 and C2H6. In addition, FJI-C1 with hydrophilic internal pores surfaces shows highly efficient adsorption separation of polar molecules from nonpolar molecules. Notably, it exhibits high separation selectivity for benzene over cyclohexane due to the π-π interactions between benzene molecules and s-triazine rings of the porous MOF. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. An Azine-Linked Covalent Organic Framework: Synthesis, Characterization and Efficient Gas Storage.

    Science.gov (United States)

    Li, Zhongping; Zhi, Yongfeng; Feng, Xiao; Ding, Xuesong; Zou, Yongcun; Liu, Xiaoming; Mu, Ying

    2015-08-17

    A azine-linked covalent organic framework, COF-JLU2, was designed and synthesized by condensation of hydrazine hydrate and 1,3,5-triformylphloroglucinol under solvothermal conditions for the first time. The new covalent organic framework material combines permanent micropores, high crystallinity, good thermal and chemical stability, and abundant heteroatom activated sites in the skeleton. COF-JLU2 possesses a moderate BET surface area of over 410 m(2)  g(-1) with a pore volume of 0.56 cm(3)  g(-1) . Specifically, COF-JLU2 displays remarkable carbon dioxide uptake (up to 217 mg g(-1) ) and methane uptake (38 mg g(-1) ) at 273 K and 1 bar, as well as high CO2 /N2 (77) selectivity. Furthermore, we further highlight that it exhibits a higher hydrogen storage capacity (16 mg g(-1) ) than those of reported COFs at 77 K and 1 bar.

  7. Modelling non-equilibrium secondary organic aerosol formation and evaporation with the aerosol dynamics, gas- and particle-phase chemistry kinetic multilayer model ADCHAM

    Energy Technology Data Exchange (ETDEWEB)

    Roldin, P.; Eriksson, A. C.; Nordin, E. Z.; Hermansson, E.; Mogensen, Ditte; Rusanen, A.; Boy, Michael; Swietlicki, E.; Svenningsson, Birgitta; Zelenyuk, Alla; Pagels, J.

    2014-08-11

    We have developed the novel Aerosol Dynamics, gas- and particle- phase chemistry model for laboratory CHAMber studies (ADCHAM). The model combines the detailed gas phase Master Chemical Mechanism version 3.2, an aerosol dynamics and particle phase chemistry module (which considers acid catalysed oligomerization, heterogeneous oxidation reactions in the particle phase and non-ideal interactions between organic compounds, water and inorganic ions) and a kinetic multilayer module for diffusion limited transport of compounds between the gas phase, particle surface and particle bulk phase. In this article we describe and use ADCHAM to study: 1) the mass transfer limited uptake of ammonia (NH3) and formation of organic salts between ammonium (NH4+) and carboxylic acids (RCOOH), 2) the slow and almost particle size independent evaporation of α-pinene secondary organic aerosol (SOA) particles, and 3) the influence of chamber wall effects on the observed SOA formation in smog chambers.

  8. CO2 Binding Organic Liquids Gas Capture with Polarity Swing Assisted Regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Heldebrant, David [Battelle Memorial Institute, Columbus, OH (United States)

    2014-05-31

    This report outlines the comprehensive bench-scale testing of the CO2-binding organic liquids (CO2BOLs) solvent platform and its unique Polarity Swing Assisted Regeneration (PSAR). This study outlines all efforts on a candidate CO2BOL solvent molecule, including solvent synthesis, material characterization, preliminary toxicology studies, and measurement of all physical, thermodynamic and kinetic data, including bench-scale testing. Equilibrium and kinetic models and analysis were made using Aspen Plus™. Preliminary process configurations, a technoeconomic assessment and solvent performance projections for separating CO2 from a subcritical coal-fired power plant are compared to the U.S. Department of Energy's Case 10 monoethanolamine baseline.

  9. Organic matter sources, fluxes and greenhouse gas exchange in the Oubangui River (Congo River basin)

    Science.gov (United States)

    Bouillon, S.; Yambélé, A.; Spencer, R. G. M.; Gillikin, D. P.; Hernes, P. J.; Six, J.; Merckx, R.; Borges, A. V.

    2012-06-01

    The Oubangui is a major tributary of the Congo River, draining an area of ~500 000 km2 mainly consisting of wooded savannahs. Here, we report results of a one year long, 2-weekly sampling campaign in Bangui (Central African Republic) since March 2010 for a suite of physico-chemical and biogeochemical characteristics, including total suspended matter (TSM), bulk concentration and stable isotope composition of particulate organic carbon (POC and δ13CPOC), particulate nitrogen (PN and δ15NPN), dissolved organic carbon (DOC and δ13CDOC), dissolved inorganic carbon (DIC and δ13CDIC), dissolved greenhouse gases (CO2, CH4 and N2O), and dissolved lignin composition. δ13C signatures of both POC and DOC showed strong seasonal variations (-30.6 to -25.8‰, and -31.8 to -27.1‰, respectively), but their different timing indicates that the origins of POC and DOC may vary strongly over the hydrograph and are largely uncoupled, differing up to 6‰ in δ13C signatures. Dissolved lignin characteristics (carbon-normalised yields, cinnamyl:vanillyl phenol ratios, and vanillic acid to vanillin ratios) showed marked differences between high and low discharge conditions, consistent with major seasonal variations in the sources of dissolved organic matter. We observed a strong seasonality in pCO2, ranging between 470 ± 203 ppm for Q < 1000 m3 s-1 (n=10) to a maximum of 3750 ppm during the first stage of the rising discharge. The low POC/PN ratios, high %POC and low and variable δ13CPOC signatures during low flow conditions suggest that the majority of the POC pool during this period consists of in situ produced phytoplankton, consistent with concurrent pCO2 (partial pressure of CO2) values only slightly above and, occasionally, below atmospheric equilibrium. Water-atmosphere CO2 fluxes estimated using two independent approaches averaged 105 and 204 g C m-2 yr-1, i.e. more than an order of magnitude lower than current estimates for large tropical rivers globally. Although

  10. Crystal engineering on superpolyhedral building blocks in metal-organic frameworks applied in gas adsorption.

    Science.gov (United States)

    Chen, Ying Pin; Liu, Tian Fu; Fordham, Stephen; Zhou, Hong Cai

    2015-12-01

    Two metal-organic frameworks [PCN-426(Ni) and PCN-427(Cu)] have been designed and synthesized to investigate the structure predictability using a SBB (supermolecular building blocks) approach. Tetratopic ligands featuring 120° angular carboxylate moieties were coordinated with a [Ni3(μ3-O)] cluster and a [Cu2O2] unit, respectively. As topologically predicted, 4-connected networks with square coordination adopted the nbo net for the Ni-MOF and ssb net for the Cu-MOF. PCN-426(Ni) was augmented with 12-connected octahedral SBBs, while PCN-427(Cu) was constructed with tetragonal open channels. After a CO2 supercritical drying procedure, the PCN-426(Ni) possessed a Brunauer-Emmett-Teller (BET) surface area as high as 3935 m(2) g(-1) and impressively high N2 uptake of 1500 cm(3) g(-1). This work demonstrates the generalization of the SBB strategy, finding an alternative to inconvenient synthetic processes to achieve the desired structural features.

  11. Greenhouse gas and ammonia emissions from composting of animal manure and other organic waste products

    DEFF Research Database (Denmark)

    Chowdhury, Md Albarune

    on human health and ecosystem health. Thus, alternative technologies for recycling manure and utilising it as a nutrient source for crop production, while minimising the environmental costs, are important for the sustainability of the livestock and poultry sectors. Composting of animal manure and other......, but information on its effect on GHG emissions, especially nitrous oxide (N2O), is still limited. This thesis investigated the main processes and factors affecting the physicochemical composition of the compost and emissions of GHG and NH3 during composting of animal manure and other organic waste products....... Laboratory studies showed that differences in the initial physical properties (moisture, bulk density, particle density and air-filled porosity) of separated animal slurry solid fractions (SSF) had a considerable impact on the development of compost maximum temperatures (40-70 o C) and the time required (2...

  12. Organic matter sources, fluxes and greenhouse gas exchange in the Oubangui River (Congo River basin

    Directory of Open Access Journals (Sweden)

    S. Bouillon

    2012-06-01

    Full Text Available The Oubangui is a major tributary of the Congo River, draining an area of ~500 000 km2 mainly consisting of wooded savannahs. Here, we report results of a one year long, 2-weekly sampling campaign in Bangui (Central African Republic since March 2010 for a suite of physico-chemical and biogeochemical characteristics, including total suspended matter (TSM, bulk concentration and stable isotope composition of particulate organic carbon (POC and δ13CPOC, particulate nitrogen (PN and δ15NPN, dissolved organic carbon (DOC and δ13CDOC, dissolved inorganic carbon (DIC and δ13CDIC, dissolved greenhouse gases (CO2, CH4 and N2O, and dissolved lignin composition. δ13C signatures of both POC and DOC showed strong seasonal variations (−30.6 to −25.8‰, and −31.8 to −27.1‰, respectively, but their different timing indicates that the origins of POC and DOC may vary strongly over the hydrograph and are largely uncoupled, differing up to 6‰ in δ13C signatures. Dissolved lignin characteristics (carbon-normalised yields, cinnamyl:vanillyl phenol ratios, and vanillic acid to vanillin ratios showed marked differences between high and low discharge conditions, consistent with major seasonal variations in the sources of dissolved organic matter. We observed a strong seasonality in pCO2, ranging between 470 ± 203 ppm for Q < 1000 m3 s−1 (n=10 to a maximum of 3750 ppm during the first stage of the rising discharge. The low POC/PN ratios, high %POC and low and variable δ13CPOC signatures during low flow conditions suggest that the majority of the POC pool during this period consists of in situ produced phytoplankton, consistent with concurrent pCO2 (partial pressure of CO2 values only slightly

  13. Titan's organic aerosols: Molecular composition and structure of laboratory analogues inferred from pyrolysis gas chromatography mass spectrometry analysis

    Science.gov (United States)

    Morisson, Marietta; Szopa, Cyril; Carrasco, Nathalie; Buch, Arnaud; Gautier, Thomas

    2016-10-01

    samples even if the number of released compounds can significantly differ. The hydrocarbon chain content increases in tholins when the CH4 ratio increases. A semi-quantitative study of the nitriles (most abundant chemical family in our chromatograms) released during the pyrolysis shows the existence of a correlation between the amount of a nitrile released and its molecular mass, similarly to the previous quantification of nitriles in the plasma gas-phase. Moreover, numerous nitriles are present both in tholins and in the gas phase, confirming their suspected role in the gas phase as precursors of the solid organic particles.

  14. Greenhouse gas fluxes from drained organic soils - a synthesis of a large dataset

    Science.gov (United States)

    Tiemeyer, Bärbel

    2016-04-01

    Drained peatlands are hotspots of greenhouse gas (GHG) emissions. Agriculture is the major land use type for peatlands in Germany and other European countries, but strongly varies in its intensity regarding groundwater level and agricultural management. Although the mean annual water table depth is sometimes proposed as an overall predictor for GHG emissions, there is a strong variability of its effects on different peatlands. We synthesized 164 annual GHG budgets for 65 different sites in 13 German peatlands. Land use comprised arable land with different crops (n = 17) and grassland with a management gradient from very intensive use with up to five cuts per year to partially rewetted conservation grassland (n = 48). Carbon dioxide (net ecosystem exchange and ecosystem respiration), nitrous oxide and methane fluxes were measured with transparent and opaque manual chambers. Besides the GHG fluxes, biomass yield, fertilisation, groundwater level, climatic data, vegetation composition and soil properties were measured. Overall, we found a large variability of the total GHG budget ranging from small uptakes to extremely high emissions (> 70 t CO2-equivalents/(ha yr)). At nearly all sites, carbon dioxide was the major component of the GHG budget. Site conditions, especially the nitrogen content of the unsaturated zone and the intra-annual water level distribution, dominated the GHG emissions from grassland. Although these factors are influenced by natural conditions (peat type, regional hydrology), they could be modified by an improved water management. In the case of grassland, agricultural management such as the number of cuts had only a minor influence on the GHG budgets. Given comparable site conditions, there was no significant difference between the emissions from grassland and arable land. Due to the large heterogeneity of site conditions and crop types, emissions from arable land are difficult to explain, but management decisions such as the duration of soil

  15. Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

    Institute of Scientific and Technical Information of China (English)

    Laila Salim Al Hashmi; Mohammad Amzad Hossain; Afaf Mohammed Weli; Qasim Al-Riyami; Jamal Nasser Al-Sabahi

    2013-01-01

    Objective: To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L (T. vulgaris) by gas chromatography-mass spectrometry (GC-MS). Methods: The shade dried leaves powder was extracted with methanol by using Soxhlet extractor. Methanol crude extracts of T. vulgaris and the derived fractions of hexane, chloroform, ethyl acetate and butanol were obtained. Results: Qualitative analyses of various organic crude extracts of T. vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds. Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important. Further, the T. vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation. The crude extracts were prepared from the powder leaves of T. vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis. Conclusions: All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T. vulgaris are biologically active molecules. Thus the identification of a good number of compounds in various crude extracts of T. vulgaris might have some ecological role.

  16. Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

    Institute of Scientific and Technical Information of China (English)

    Laila; Salim; Al; Hashmi; Mohammad; Amzad; Hossain; Afaf; Mohammed; Weli; Qasim; Al-Riyami; Jamal; Nasser; Al-Sabahi

    2013-01-01

    Objective:To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L(T.vulgaris)by gas chromatography-mass spectrometry(GC-MS).Methods:The shade dried leaves powder was extracted with methanol by using Soxhlet extractor.Methanol crude extracts of T.vulgaris and the derived fractions of hexane,chloroform,ethyl acetate and butanol were obtained.Results:Qualitative analyses of various organic crude extracts of T.vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds.Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important.Further,the T.vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation.The crude extracts were prepared from the powder leaves of T.vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis.Conclusions:All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T.vulgaris are biologically active molecules.Thus the identification of a good number of compounds in various crude extracts of T.vulgaris might have some ecological role.

  17. Gas adsorption and structural diversity in a family of Cu(II) pyridyl-isophthalate metal-organic framework materials

    Science.gov (United States)

    Gould, Jamie A.; Athwal, Harprit Singh; Blake, Alexander J.; Lewis, William; Hubberstey, Peter; Champness, Neil R.; Schröder, Martin

    2017-01-01

    A family of Cu(II)-based metal-organic frameworks (MOFs) has been synthesized using three pyridyl-isophthalate ligands, H2L1 (4'-(pyridin-4-yl)biphenyl-3,5-dicarboxylic acid), H2L2 (4''-(pyridin-4-yl)-1,1':4',1''-terphenyl-3,5-dicarboxylic acid) and H2L3 (5-[4-(pyridin-4-yl)naphthalen-1-yl]benzene-1,3-dicarboxylic acid). Although in each case the pyridyl-isophthalate ligands adopt the same pseudo-octahedral [Cu2(O2CR)4N2] paddlewheel coordination modes, the resulting frameworks are structurally diverse, particularly in the case of the complex of Cu(II) with H2L3, which leads to three distinct supramolecular isomers, each derived from Kagomé and square nets. In contrast to [Cu(L2)] and the isomers of [Cu(L3)], [Cu(L1)] exhibits permanent porosity. Thus, the gas adsorption properties of [Cu(L1)] were investigated with N2, CO2 and H2, and the material exhibits an isosteric heat of adsorption competitive with leading MOF sorbents for CO2. [Cu(L1)] displays high H2 adsorption, with the density in the pores approaching that of liquid H2. This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  18. In situ analysis of the Martian soil by gas chromatography: decoding of complex chromatograms of organic molecules of exobiological interest.

    Science.gov (United States)

    Pietrogrande, M C; Zampolli, M G; Dondi, F; Szopa, C; Sternberg, R; Buch, A; Raulin, F

    2005-04-15

    Gas chromatography-mass spectrometry (GC-MS) will be used in future space exploration missions, in order to seek organic molecules at the surface of Mars, and especially potential chemical indicators of life. Carboxylic acids are among the most expected organic species at the surface of Mars, and they could be numerous in the analysed samples. For this reason, a chemometric method was applied to support the interpretation of chromatograms of carboxylic acid mixtures. The method is based on AutoCovariance Function (ACVF) in order to extract information on the sample--number and chemical structure of the components--and on separation performance. The procedure was applied to standard samples containing targeted compounds which are among the most expected to be present in the Martian soil: n-alkanoic and benzene dicarboxylic acids. ACVF was computed on the obtained chromatograms and plotted versus retention time: peaks of the ACVF plot can be related to specific molecular structures and are diagnostic for chemical identification of compounds.

  19. Infrared spectroscopy of methoxyphenols involved as atmospheric secondary organic aerosol precursors: Gas-phase vibrational cross-sections

    Science.gov (United States)

    Cuisset, A.; Coeur, C.; Mouret, G.; Ahmad, W.; Tomas, A.; Pirali, O.

    2016-08-01

    Methoxyphenols are emitted in the atmosphere from biomass burning and recent works have shown the potential role of these oxygenated aromatic species in the formation of secondary organic aerosols. IR spectroscopic data that would enable their remote measurement in the atmosphere remain scarce in the literature. Room temperature Far-IR cross-sections of 4 methoxyphenols (2-methoxyphenol or guaiacol, 3-methoxyphenol, 4-methoxyphenol and 2,6-dimethoxyphenol or syringol) have been determined using the THz synchrotron radiation available at SOLEIL. Mid- and near-IR regions have also been investigated with a conventional Fourier transform IR setup and allowed to provide a set of vibrational cross-sections of the studied methoxyphenols. Finally, gas-phase cross sections of two nitroguaiacol isomers (4-nitroguaiacol and 5-nitroguaiacol), two intermediate products involved in the formation of secondary organic aerosols have been measured in the mid- and near-IR with a heated multi-pass cell. Harmonic and anharmonic density functional theory calculations were carried out for all the studied compounds and allowed a full assignment of the recorded rovibrational bands.

  20. Chemically blockable transformation and ultraselective low-pressure gas adsorption in a non-porous metal organic framework.

    Science.gov (United States)

    Xiao, Bo; Byrne, Peter J; Wheatley, Paul S; Wragg, David S; Zhao, Xuebo; Fletcher, Ashleigh J; Thomas, K Mark; Peters, Lars; Evans, John S O; Warren, John E; Zhou, Wuzong; Morris, Russell E

    2009-07-01

    Metal organic frameworks (MOFs) are among the most exciting materials discovered recently, attracting particular attention for their gas-adsorption and -storage properties. Certain MOFs show considerable structural flexibility in response to various stimuli. Although there are several examples of 'breathing' MOFs, in which structural changes occur without any bond breaking, examples of transformations in which several bonds are broken and made are much rarer. In this paper we demonstrate how a flexible MOF, Cu2(OH)(C8H3O7S)(H2O)2H2O, can be synthesized by careful choice of the organic linker ligand. The flexibility can be controlled by addition of a supplementary coordinating molecule, which increases the thermal stability of the solid sufficiently for direct imaging with electron microscopy to be possible. We also demonstrate that the MOF shows unprecedented low-pressure selectivity towards nitric oxide through a coordination-driven gating mechanism. The chemical control over these behaviours offers new possibilities for the synthesis of MOFs with unusual and potentially exploitable properties.

  1. Sample Processing technique onboard ExoMars (MOMA) to analyze organic compounds by Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Buch, A.; Freissinet, C.; Sternberg, R.; Szopa, C.; Coll, P. J.; Brault, A.; Pinnick, V.; Siljeström, S.; Raulin, F.; Steininger, H.; Goesmann, F.; MOMA Team

    2011-12-01

    With the aim of separating and detecting organic compounds from Martian soil onboard the Mars Organic Molecule Analyzer (MOMA) experiment of the ExoMars 2018 upcoming joint ESA/NASA mission, we have developed three different space compatible sample preparation techniques compatible with space missions, able to extract and analyze by GC-MS a wide range of volatile and refractory compounds, including chirality analysis. Then, a sample processing utilizing three derivatization/extraction reactions has been carried out. The first reaction is based on a silyl reagent N-Methyl-N- (Tert-Butyldimethylsilyl)trifluoroacetamide (MTBSTFA) [1], the second one, N,N-Dimethylformamide Dimethylacetal (DMF-DMA) [2,3] is dedicated to the chirality detection and the third one is a thermochemolysis based on the use of tetramethylammoniumhydroxide (TMAH). The sample processing system is performed in an oven, dedicated to the MOMA experiment containing the solid sample (50-100mg). The internal temperature of the oven ranges from 20 to 900 °C. The extraction step is achieved by using thermodesorption in the range of 100 to 300°C for 5 to 20 min. Then, the chemical derivatization of the extracted compounds is performed directly on the soil sample by using a derivatyization capsule which contains a mixture of MTBSTFA-DMF or DMF-DMA solution when enantiomeric separation is required. By decreasing the polarity of the targeted molecules, this step allows their volatilization at a temperature below 250°C without any thermal degradation. Once derivatized, the volatile target molecules are trapped in a chemical trap and promptly desorbed into the gas chromatograph coupled to a mass spectrometer. Thermochemolysis is directly performed in the oven at 400°C during 5 min with a 25% (w/w) methanol solution of tetramethylammonium hydroxide (TMAH). Then, pyrolysis in the presence of TMAH allows both an efficient cleavage of polar bonds and the subsequent methylation of COOH, OH and NH2 groups, hence

  2. Comparison of two common adsorption materials for thermal desorption gas chromatography - mass spectrometry of biogenic volatile organic compounds.

    Science.gov (United States)

    Marcillo, Andrea; Jakimovska, Viktorija; Widdig, Anja; Birkemeyer, Claudia

    2017-09-08

    Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatography (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for non-polar to semipolar volatiles, however, many volatiles from environmental and biological samples possess a rather polar character. Therefore, we tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (bp. 20-256°C) and different chemical classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At first, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, we tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Moreover, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture. Volatiles were analyzed in a range between 0.01-∼250ng/tube depending on the compound and material. Lower limits of quantitation were between 0.01 and 3 ng±0.9). Interestingly, we found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Crystal engineering on superpolyhedral building blocks in metal–organic frameworks applied in gas adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying-Pin; Liu, Tian-Fu; Fordham, Stephen; Zhou, Hong-Cai

    2015-11-07

    Two metal–organic frameworks [PCN-426(Ni) and PCN-427(Cu)] have been designed and synthesized to investigate the structure predictability using a SBB (supermolecular building blocks) approach. Tetratopic ligands featuring 120° angular carboxylate moieties were coordinated with a [Ni33-O)] cluster and a [Cu2O2] unit, respectively. As topologically predicted, 4-connected networks with square coordination adopted thenbonet for the Ni-MOF andssbnet for the Cu-MOF. PCN-426(Ni) was augmented with 12-connected octahedral SBBs, while PCN-427(Cu) was constructed with tetragonal open channels. After a CO2supercritical drying procedure, the PCN-426(Ni) possessed a Brunauer–Emmett–Teller (BET) surface area as high as 3935 m2 g-1and impressively high N2uptake of 1500 cm3 g-1. This work demonstrates the generalization of the SBB strategy, finding an alternative to inconvenient synthetic processes to achieve the desired structural features.

  4. Elemental and organic carbon in flue gas particles of various wood combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaegauf, C.; Schmid, M.; Guentert, P.

    2005-12-15

    The airborne particulate matter (PM) in the environment is of ever increasing concern to authorities and the public. The major fractions of particles in wood combustion processes are in the size less than 1 micron, typically in the range of 30 to 300 nm. Of specific interest is the content of the elemental carbon (EC) and organic carbon (OC) in the particles since these substances are known for its particular potential as carcinogens. Various wood combustion systems have been analysed (wood chip boiler, pellet boiler, wood log boiler, wood stove and open fire). The sampling of the particles was done by mean of a multi-stage particle sizing sampler cascade impactor. The impactor classifies the particles collected according to their size. The 7 stages classify the particles between 0.4 and 9 microns aerodynamic diameter. The analytical method for determining the content of EC and OC in the particles is based on coulometry. The coulometer measures the conductivity of CO{sub 2} released by oxidation of EC in the samples at 650 {sup o}C. The OC content is determined by pyrolysis of the particle samples in helium atmosphere.

  5. Selection of ionic liquids for enhancing the gas solubility of volatile organic compounds.

    Science.gov (United States)

    Gonzalez-Miquel, Maria; Palomar, Jose; Rodriguez, Francisco

    2013-01-10

    A systematic thermodynamic analysis has been carried out for selecting cations and anions to enhance the absorption of volatile organic compounds (VOCs) at low concentration in gaseous streams by ionic liquids (ILs), using COSMO-RS methodology. The predictability of computational procedure was validated by comparing experimental and COSMO-RS calculated Henry's law constant data over a sample of 125 gaseous solute-IL systems. For more than 2400 solute-IL mixtures evaluated, including 9 solutes and 270 ILs, it was found that the lower the activity coefficient at infinite dilution (γ(∞)) of solutes in the ILs, the more the exothermic excess enthalpy (H(E)) of the equimolar IL-solute mixtures. Then, the solubility of a representative sample of VOC solutes, with very different chemical nature, was screened in a wide number of ILs using COSMO-RS methodology by means of γ(∞) and H(E) parameters, establishing criteria to select the IL structures that promote favorable solute-solvent intermolecular interactions. As a result of this analysis, an attempt of classification of VOCs respect to their potential solubility in ILs was proposed, providing insights to rationally select the cationic and anionic species for a possible development of absorption treatments of VOC pollutants based on IL systems.

  6. Kinetic modeling of mechanisms of industrially important organic reactions in gas and liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Vahteristo, K.

    2010-07-01

    This dissertation is based on 5 articles which deal with reaction mechanisms of the following selected industrially important organic reactions: 1. dehydrocyclization of n-butylbenzene to produce naphthalene, 2. dehydrocyclization of 1-(p-tolyl)-2-methylbutane (MB) to produce 2,6-dimethylnaphthalene, 3. esterification of neopentyl glycol (NPG) with different carboxylic acids to produce monoesters, 4. skeletal isomerization of 1-pentene to produce 2-methyl-1-butene and 2-methyl-2-butene. The results of initial- and integral-rate experiments of n-butylbenzene dehydrocyclization over selfmade chromia/alumina catalyst were applied when investigating reaction 2. Reaction 2 was performed using commercial chromia/alumina of different acidity, platina on silica and vanadium/calcium/alumina as catalysts. On all catalysts used for the dehydrocyclization, major reactions were fragmentation of MB and 1-(p-tolyl)-2-methylbutenes (MBes), dehydrogenation of MB, double bond transfer, hydrogenation and 1,6-cyclization of MBes. Minor reactions were 1,5-cyclization of MBes and methyl group fragmentation of 1,6- cyclization products. Esterification reactions of NPG were performed using three different carboxylic acids: propionic, isobutyric and 2-ethylhexanoic acid. Commercial heterogeneous gellular (Dowex 50WX2), macroreticular (Amberlyst 15) type resins and homogeneous para-toluene sulfonic acid were used as catalysts. At first NPG reacted with carboxylic acids to form corresponding monoester and water. Then monoester esterified with carboxylic acid to form corresponding diester. In disproportionation reaction two monoester molecules formed NPG and corresponding diester. All these three reactions can attain equilibrium. Concerning esterification, water was removed from the reactor in order to prevent backward reaction. Skeletal isomerization experiments of 1-pentene were performed over HZSM-22 catalyst. Isomerization reactions of three different kind were detected: double bond, cis

  7. Quantification of diesel exhaust gas phase organics by a thermal desorption proton transfer reaction mass spectrometer

    Directory of Open Access Journals (Sweden)

    M. H. Erickson

    2012-02-01

    Full Text Available A new approach was developed to measure the total abundance of long chain alkanes (C12 and above in urban air using thermal desorption with a proton transfer reaction mass spectrometer (PTR-MS. These species are emitted in diesel exhaust and may be important precursors to secondary organic aerosol production in urban areas. Long chain alkanes undergo dissociative proton transfer reactions forming a series of fragment ions with formula CnH2n+1. The yield of the fragment ions is a function of drift conditions. At a drift field strength of 80 Townsends, the most abundant ion fragments from C10 to C16 n-alkanes were m/z 57, 71 and 85. The PTR-MS is insensitive to n-alkanes less than C8 but displays an increasing sensitivity for larger alkanes. Higher drift field strengths yield greater normalized sensitivity implying that the proton affinity of the long chain n-alkanes is less than H2O. Analysis of diesel fuel shows the mass spectrum was dominated by alkanes (CnH2n+1, monocyclic aromatics, and an ion group with formula CnH2n−1 (m/z 97, 111, 125, 139. The PTR-MS was deployed in Sacramento, CA during the Carbonaceous Aerosols and Radiative Effects Study field experiment in June 2010. The ratio of the m/z 97 to 85 ion intensities in ambient air matched that found in diesel fuel. Total diesel exhaust alkane concentrations calculated from the measured abundance of m/z 85 ranged from the method detection limit of ~1 μg m−3 to 100 μg m−3 in several air pollution episodes. The total diesel exhaust alkane concentration determined by this method was on average a factor of 10 greater than the sum of alkylbenzenes associated with spark ignition vehicle exhaust.

  8. Stability of metal organic frameworks and interaction of small gas molecules in these materials

    Science.gov (United States)

    Tan, Kui

    The work in this dissertation combines spectroscopy ( in-situ infrared absorption and Raman), powder X-ray diffraction and DFT calculations to study the stability of metal organic frameworks materials (MOFs) in the presence of water vapor and other corrosive gases (e.g., SO 2, NO2 NO), and the interaction and competitive co-adsorption of several gases within MOFs by considering two types of prototypical MOFs: 1) a MOF with saturated metal centers based on paddlewheel secondary building units: M(bdc)(ted)0.5 [M=Cu, Zn, Ni, Co, bdc = 1,4-benzenedicarboxylate, ted = triethylenediamine], and 2) a MOF with unsaturated metal centers: M2(dobdc) [M=Mg2+, Zn2+, Ni2+, Co2+ and dobdc = 2,5-dihydroxybenzenedicarboxylate]. We find that the stability of MOFs to water vapor critically depends on their structure and the specific metal cation in the building units. For M(bdc)(ted)0.5, the metal-bdc bond is the most vulnerable for Cu(bdc)(ted)0.5, while the metal-ted bond is first attacked for the Zn and Co analogs. In contrast, Ni(bdc)(ted)0.5 remains stable under the same conditions. For M2(dobdc), or MOF-74, the weak link is the dobdc-metal bond. The water molecule is dissociatively adsorbed at the metal-oxygen group with OH adsorption directly on the metal center and H adsorption on the bridging O of the phenolate group in the dobdc linker. Other technologically important molecules besides water, such as NO, NO2, SO2, tend to poison M2(dobdc) through dissociative or molecular adsorption onto the open metal sites. A high uptake SO2 capacity was measured in M(bdc)(ted)0.5, attributed to multipoint interactions between the guest SO2 molecule and the MOF host. In the case of competitive co-adsorption between CO2 and other small molecules, we find that binding energy alone is not a good indicator of molecular site occupation within the MOF (i.e., it cannot successfully predict and evaluate the displacement of CO2 by other molecules). Instead, we show that the kinetic barrier for the

  9. Direct thermal desorption of semivolatile organic compounds from diffusion denuders and gas chromatographic analysis for trace concentration measurement.

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, D. E.; Perlinger, J. A.; Morrow, P. S.; Doskey, P. V.; Perram, D.L.; Environmental Science Division; Michigan Technological Univ.

    2007-01-01

    A novel method for collection and analysis of vapor-phase semivolatile organic compounds (SOCs) in ambient air is presented. The method utilizes thermal desorption of SOCs trapped in diffusion denuders coupled with cryogenic preconcentration on Tenax-TA and analysis by high resolution gas chromatography (GC)-electron-capture detection (ECD). The sampling and analysis methods employ custom-fabricated multicapillary diffusion denuders, a hot gas spike (HGS) apparatus to load known quantities of thermally stable standards into diffusion denuders prior to sample collection, a custom-fabricated oven to thermally desorb SOCs from the diffusion denuder, and a programmable temperature vaporization (PTV) inlet containing a liner packed with Tenax-TA for effective preconcentration of the analytes and water management. High flow rates into the PTV inlet of 750 mL min-1during thermal desorption are ca. a factor of ten greater than typically used. To improve resolution and retention time stability, the thermal desorption and PTV inlet programming procedure includes three steps to prevent water from entering the analytic column while effectively transferring the analytes into the GC system. The instrumentation and procedures provide virtually complete and consistent transfer of analytes collected from ambient air into the GC evidenced by recovery of seven replicates of four internal standards of 90.7 {+-} 4.0-120 {+-} 23% (mean {+-} 95% confidence interval, CI). Retention time based compound identification is facilitated by low retention time variability with an average 95% CI of 0.024 min for sixteen replicates of eight standards. Procedure details and performance metrics as well as ambient sampling results are presented.

  10. Direct thermal desorption of semivolatile organic compounds from diffusion denuders and gas chromatographic analysis for trace concentration measurement.

    Science.gov (United States)

    Tobias, David E; Perlinger, Judith A; Morrow, Patrick S; Doskey, Paul V; Perram, David L

    2007-01-26

    A novel method for collection and analysis of vapor-phase semivolatile organic compounds (SOCs) in ambient air is presented. The method utilizes thermal desorption of SOCs trapped in diffusion denuders coupled with cryogenic preconcentration on Tenax-TA and analysis by high resolution gas chromatography (GC)-electron-capture detection (ECD). The sampling and analysis methods employ custom-fabricated multicapillary diffusion denuders, a hot gas spike (HGS) apparatus to load known quantities of thermally stable standards into diffusion denuders prior to sample collection, a custom-fabricated oven to thermally desorb SOCs from the diffusion denuder, and a programmable temperature vaporization (PTV) inlet containing a liner packed with Tenax-TA for effective preconcentration of the analytes and water management. High flow rates into the PTV inlet of 750mLmin(-1)during thermal desorption are ca. a factor of ten greater than typically used. To improve resolution and retention time stability, the thermal desorption and PTV inlet programming procedure includes three steps to prevent water from entering the analytic column while effectively transferring the analytes into the GC system. The instrumentation and procedures provide virtually complete and consistent transfer of analytes collected from ambient air into the GC evidenced by recovery of seven replicates of four internal standards of 90.7+/-4.0-120+/-23% (mean+/-95% confidence interval, CI). Retention time based compound identification is facilitated by low retention time variability with an average 95% CI of 0.024min for sixteen replicates of eight standards. Procedure details and performance metrics as well as ambient sampling results are presented.

  11. Prediction of gas collection efficiency and particle collection artifact for atmospheric semivolatile organic compounds in multicapillary denuders.

    Science.gov (United States)

    Rowe, Mark D; Perlinger, Judith A

    2010-01-15

    A modeling approach is presented to predict the sorptive sampling collection efficiency of gaseous semivolatile organic compounds (SOCs) and the artifact caused by collection of particle-associated SOCs in multicapillary diffusion denuders containing polydimethylsiloxane (PDMS) stationary phase. Approaches are presented to estimate the equilibrium PDMS-gas partition coefficient (K(pdms)) from a solvation parameter model for any compound, and, for nonpolar compounds, from the octanol-air partition coefficient (K(oa)) if measured K(pdms) values are not available. These estimated K(pdms) values are compared with K(pdms) measured by gas chromatography. Breakthrough fraction was measured for SOCs collected from ambient air using high-flow (300 L min(-1)) and low-flow (13 L min(-1)) denuders under a range of sampling conditions (-10 to 25 degrees C; 11-100% relative humidity). Measured breakthrough fraction agreed with predictions based on frontal chromatography theory using K(pdms) and equations of Golay, Lövkvist and Jönsson within measurement precision. Analytes included hexachlorobenzene, 144 polychlorinated biphenyl congeners, and polybrominated diphenyl ethers 47 and 99. Atmospheric particle transmission efficiency was measured for the high-flow denuder (0.037-6.3 microm diameter), and low-flow denuder (0.015-3.1 microm diameter). Particle transmission predicted using equations of Gormley and Kennedy, Pich, and a modified filter model, agreed within measurement precision (high-flow denuder) or were slightly greater than (low-flow denuder) measured particle transmission. As an example application of the model, breakthrough volume and particle collection artifact for the two denuder designs were predicted as a function of K(oa) for nonpolar SOCs. The modeling approach is a necessary tool for the design and use of denuders for sorptive sampling with PDMS stationary phase.

  12. Multi-generation gas-phase oxidation, equilibrium partitioning, and the formation and evolution of secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2012-10-01

    Full Text Available A new model of secondary organic aerosol (SOA formation is developed that explicitly takes into account multi-generational oxidation as well as fragmentation of gas-phase compounds, and assumes equilibrium gas-particle partitioning. The model framework requires specification of a limited number of tunable parameters to describe the kinetic evolution of SOA mass, the average oxygen-to-carbon atomic ratio and the mean particle volatility as oxidation proceeds. These parameters describe (1 the relationship between oxygen content and volatility, (2 the probability of fragmentation and (3 the amount of oxygen added per reaction. The time-evolution and absolute value of the simulated SOA mass depends sensitively on all tunable parameters. Of the tunable parameters, the mean O : C is most sensitive to the oxygen/volatility relationship, exhibiting only a weak dependence on the other relationships. The model mean particle O : C produced from a given compound is primarily controlled by the number of carbon atoms comprising the SOA precursor, with some sensitivity to the specified oxygen/volatility relationship. The model is tested against laboratory measurements of time-dependent SOA formation from the photooxidation of α-pinene and n-pentadecane and performs well (after tuning. The model can also accurately simulate the carbon-number dependence of aerosol yields previously observed for oxidation of straight-chain alkanes. This model may provide a generalized framework for the interpretation of laboratory SOA formation experiments in which explicit consideration of multiple-generations of products is required, which is true for all photo-oxidation experiments.

  13. Characterization of thermal desorption with the Deans-switch technique in gas chromatographic analysis of volatile organic compounds.

    Science.gov (United States)

    Ou-Yang, Chang-Feng; Huang, Ying-Xue; Huang, Ting-Jyun; Chen, Yong-Shen; Wang, Chieh-Heng; Wang, Jia-Lin

    2016-09-02

    This study presents a novel application based on the Deans-switch cutting technique to characterize the thermal-desorption (TD) properties for gas chromatographic (GC) analysis of ambient volatile organic compounds (VOCs). Flash-heating of the sorbent bed at high temperatures to desorb trapped VOCs to GC may easily produce severe asymmetric or tailing GC peaks affecting resolution and sensitivity if care is not taken to optimize the TD conditions. The TD peak without GC separation was first examined for the quality of the TD peak by analyzing a standard gas mixture from C2 to C12 at ppb level. The Deans switch was later applied in two different stages. First, it was used to cut the trailing tail of the TD peak, which, although significantly improved the GC peak symmetry, led to more loss of the higher boiling compounds than the low boiling ones, thus suggesting compound discrimination. Subsequently, the Deans switch was used to dissect the TD peak into six 30s slices in series, and an uneven distribution in composition between the slices were found. A progressive decrease in low boiling compounds and increase in higher boiling ones across the slices indicated severe inhomogeneity in the TD profile. This finding provided a clear evidence to answer the discrimination problem found with the tail cutting approach to improve peak symmetry. Through the use of the innovated slicing method based on the Deans-switch cutting technique, optimization of TD injection for highly resolved, symmetric and non-discriminated GC peaks can now be more quantitatively assessed and guided.

  14. Importance of mineral cations and organics in gas-aerosol partitioning of reactive nitrogen compounds: case study based on MINOS results

    Directory of Open Access Journals (Sweden)

    S. Metzger

    2005-12-01

    Full Text Available The partitioning of reactive nitrogen compounds between the gas and the aerosol phase, as observed during the MINOS (Mediterranean INtensive Oxidant Study campaign in Crete, Greece, in July and August 2001, has been studied with three thermodynamic gas-aerosol equilibrium models (EQMs of different chemical complexity: ISORROPIA, which is limited to the ammonium sulfate-nitrate-sodium-chloride-water-system, SCAPE2, which also includes mineral elements (calcium, magnesium and potassium, and EQSAM2, which additionally accounts for organic acids. The different EQMs, as applied at the same level of complexity, generally produce comparable results within the range of measurement uncertainties (on average within ~10%, although they differ considerably in particular aspects. Model simulations of three distinct air pollution episodes during MINOS show that organic acids (lumped and soluble mineral cations need to be included in EQMs to accurately simulate the gas-aerosol partitioning of ammonia and nitric acid.

  15. Thermodynamics of the adsorption of volatile organic compounds in a binary polydimethylsiloxane-permethylated β-cyclodextrin stationary phase, as measured by gas chromatography

    Science.gov (United States)

    Onuchak, L. A.; Platonov, V. I.; Kuraeva, Yu. G.

    2013-05-01

    The sorption behavior of 29 organic compounds in a binary polydimethylsiloxane-permethylated β-cyclodextrin stationary phase is investigated using gas chromatography. The effect of the sorbates' polarity, shape, and chirality on the formation of sorbate-cyclodextrin inclusion complexes is studied.

  16. A porous metal-organic framework based on Zn6O2 clusters: chemical stability, gas adsorption properties and solvatochromic behavior.

    Science.gov (United States)

    Cui, Jiehu; Li, Yizhi; Guo, Zijian; Zheng, Hegen

    2013-01-21

    A highly connected 3D metal-organic framework with tfz-d topology based on Zn(6)O(2) clusters and flexible carboxylate ligands has been synthesized. The obtained Zn-MOF shows solvatochromic behavior for fluorescence sensing of small molecules, gas adsorption properties and exceptional chemical stability and might have applications for separation and detection purposes.

  17. Assessment of Volatile Organic Compound and Hazardous Air Pollutant Emissions from Oil and Natural Gas Well Pads using Mobile Remote and On-site Direct Measurements

    Science.gov (United States)

    Emissions of volatile organic compounds (VOC) and hazardous air pollutants (HAP) from oil and natural gas production were investigated using direct measurements of component-level emissions on well pads in the Denver-Julesburg (DJ) Basin and remote measurements of production pad-...

  18. Towards a model-based inventory of soil organic carbon in agricultural soils for the Swiss greenhouse gas reporting

    Science.gov (United States)

    Staudt, K.; Leifeld, J.; Bretscher, D.; Fuhrer, J.

    2012-04-01

    The Swiss inventory submission under the United Nations Framework Convention on Climate Change (UNFCCC) reports on changes in soil organic carbon stocks under different land-uses and land-use changes. The approach currently employed for cropland and grassland soils combines Tier 1 and Tier 2 methods and is considered overly simplistic. As the UNFCC encourages countries to develop Tier 3 methods for national greenhouse gas reporting, we aim to build up a model-based inventory of soil organic carbon in agricultural soils in Switzerland. We conducted a literature research on currently employed higher-tier methods using process-based models in four countries: Denmark, Sweden, Finland and the USA. The applied models stem from two major groups differing in complexity - those belonging to the group of general ecosystem models that include a plant-growth submodel, e.g. Century, and those that simulate soil organic matter turnover but not plant-growth, e.g. ICBM. For the latter group, carbon inputs to the soil from plant residues and roots have to be determined separately. We will present some aspects of the development of a model-based inventory of soil organic carbon in agricultural soils in Switzerland. Criteria for model evaluation are, among others, modeled land-use classes and land-use changes, spatial and temporal resolution, and coverage of relevant processes. For model parameterization and model evaluation at the field scale, data from several long-term agricultural experiments and monitoring sites in Switzerland is available. A subsequent regional application of a model requires the preparation of regional input data for the whole country - among others spatio-temporal meteorological data, agricultural and soil data. Following the evaluation of possible models and of available data, preference for application in the Swiss inventory will be given to simpler model structures, i.e. models without a plant-growth module. Thus, we compared different allometric relations

  19. The effect of feed demand on greenhouse gas emissions and farm profitability for organic and conventional dairy farms.

    Science.gov (United States)

    Kiefer, Lukas; Menzel, Friederike; Bahrs, Enno

    2014-12-01

    The reduction of product-related greenhouse gas (GHG) emissions in milk production appears to be necessary. The reduction of emissions on an individual farm might be highly accepted by farm owners if it were accompanied by an increase in profitability. Using life cycle assessments to determine the product carbon footprints (PCF) and farm-level evaluations to record profitability, we explored opportunities for optimization based on analysis of 81 organic and conventional pasture-based dairy farms in southern Germany. The objective of the present study was to detect common determining factors for low PCF and high management incomes (MI) to achieve GHG reductions at the lowest possible operational cost. In our sample, organic farms, which performed economically better than conventional farms, produced PCF that were significantly higher than those produced by conventional farms [1.61 ± 0.29 vs. 1.45 ± 0.28 kg of CO₂ equivalents (CO₂eq) per kg of milk; means ± SD)]. A multiple linear regression analysis of the sample demonstrated that low feed demand per kilogram of milk, high grassland yield, and low forage area requirements per cow are the main factors that decrease PCF. These factors are also useful for improving a farm's profitability in principle. For organic farms, a reduction of feed demand of 100 g/kg of milk resulted in a PCF reduction of 105 g of CO₂eq/kg of milk and an increase in MI of approximately 2.1 euro cents (c)/kg of milk. For conventional farms, a decrease of feed demand of 100 g/kg of milk corresponded to a reduction in PCF of 117 g of CO₂eq/kg of milk and an increase in MI of approximately 3.1 c/kg of milk. Accordingly, farmers could achieve higher profits while reducing GHG emissions. Improved education and training of farmers and consultants regarding GHG mitigation and farm profitability appear to be the best methods of improving efficiency under traditional and organic farming practices.

  20. Cogenerative Performance of a Wind − Gas Turbine − Organic Rankine Cycle Integrated System for Offshore Applications

    DEFF Research Database (Denmark)

    Bianchi, Michele; Branchini, Lisa; De Pascale, Andrea;

    2016-01-01

    Gas Turbines (GT) are widely used for power generationin offshore oil and gas facilities, due to their high reliability,compactness and dynamic response capabilities. Small heavyduty and aeroderivative units in multiple arrangements aretypically used to offer larger load flexibility, but limitede......Gas Turbines (GT) are widely used for power generationin offshore oil and gas facilities, due to their high reliability,compactness and dynamic response capabilities. Small heavyduty and aeroderivative units in multiple arrangements aretypically used to offer larger load flexibility...

  1. Assessing the impacts of changes in treatment technology on energy and greenhouse gas balances for organic waste and wastewater treatment using historical data

    DEFF Research Database (Denmark)

    Hansen, Jens Aage; Poulsen, Tjalfe

    2009-01-01

    that the organic waste quantity and composition is the same in 1970 and 2005, the technology change over this time period has resulted in a progression from a net annual GHG emission of 200 kg CO2-eq. capita ĝ€"1 in 1970 to a net saving of 170 kg CO 2-eq. capitaĝ€"1 in 2005 for management of urban organic wastes.......Historical data on organic waste and wastewater treatment during the period of 1970ĝ€"2020 were used to assess the impact of treatment on energy and greenhouse gas (GHG) balances. The assessment included the waste fractions: Sewage sludge, food waste, yard waste and other organic waste (paper...... production from the remaining organic municipal waste. Wastewater treatment has changed from direct discharge of untreated wastewater to full organic matter and nutrient (N, P) removal combined with anaerobic digestion of the sludge for biogas production with power and heat generation. These changes...

  2. Germania-based, sol-gel hybrid organic-inorganic coatings for capillary microextraction and gas chromatography.

    Science.gov (United States)

    Fang, Li; Kulkarni, Sameer; Alhooshani, Khalid; Malik, Abdul

    2007-12-15

    Germania-based, sol-gel hybrid organic-inorganic coatings were developed for capillary microextraction and gas chromatography (GC). Being an isostructural analogue of SiO2, GeO2 is compatible with the silica network. Because of this similarity, germania-based materials possess great potential for being used in the areas of chromatographic separation and sample preparation. These possibilities, however, remain practically unexplored. To our knowledge, this is the first instance that a germania-based hybrid sol-gel material is used as a sorbent in analytical sample preparation or chromatographic separation. Tetramethoxygermane was used as a precursor to create a sol-gel network via hydrolytic polycondensation reactions performed within a fused-silica capillary. The growing sol-gel germania network was simultaneously reacted with an organic ligand that contained sol-gel-active sites in its chemical structure. Three different sol-gel-active ligands were used: (a) hydroxy-terminated poly(dimethylsiloxane), (b) hydroxy-terminated poly(dimethyldiphenylsiloxane), and (c) 3-aminopropyltrimethoxysilane. Sol-gel germania-coated capillaries of desired polarity and extraction selectivity were prepared by using an appropriately selected sol-gel-active ligand in the sol solution. These capillaries were further used to extract trace concentrations of polycyclic aromatic hydrocarbons, aldehydes, ketones, alcohols, phenols, and free fatty acids from aqueous samples. The extracted solutes were further analyzed by GC-FID. The new germania-based coatings showed excellent stability under harsh operation conditions involving extreme pH values, high temperatures, and aggressive solvents. Our preliminary results also indicate that sol-gel hybrid germania coatings have the potential to offer great analytical performance as GC stationary phases.

  3. [Effects of nitrogen application on soil greenhouse gas fluxes in Eucalyptus plantations with different soil organic carbon content].

    Science.gov (United States)

    Li, Rui-Da; Zhang, Kai; Su, Dan; Lu, Fei; Wan, Wu-Xing; Wang, Xiao-Ke; Zheng, Hua

    2014-10-01

    The effects of nitrogen fertilization or nitrogen deposition on soil greenhouse gases fluxes has been well studied, while little has been piloted about the effects of nitrogen application on soil greenhouse gas fluxes and its discrepancy with different soil organic carbon content. In our study, we conducted field control experiment in a young Eucalyptus plantation in Southeast China. We compared the effects of 4 levels of nitrogen fertilization (Control: 0 kg · hm(-2); Low N: 84.2 kg · hm(-2); Medium N: 166.8 kg · hm(-2); High N: 333.7 kg · hm(-2)) on soil GHGs fluxes from 2 sites (LC and HC) with significantly different soil organic carbon (SOC) content (P Fertilization had significant priming effect on CO2 and N2O emission fluxes. One month after fertilization, both CO2 and N2O had the flux peak and decreased gradually, and the difference among the treatments disappeared at the end of the growing season. However, fertilization had no significant effect on CH4 oxidation between the 2 sites. (2) Fertilization and SOC were two crucial factors that had significant effects on CO2 and N2O emission. Fertilization had a significant positive effect on CO2 and N2O emission fluxes (P 0.05). The CO2 and N2O emission fluxes were significantly higher in HC than those in LC (P Fertilization and SOC had great interactive effect on CO2 and N2O emission (P fertilization on soil GHGs fluxes were not only in connection with the intensify of nitrogen, but also closely tied to the SOC content. When we assess the effects of nitrogen on soil GHGs fluxes, the difference induced by SOC should not be ignored.

  4. Analysis of neutral nitromusks in incenses by capillary electrophoresis in organic solvents and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Gotti, Roberto; Fiori, Jessica; Mancini, Francesca; Cavrini, Vanni

    2005-09-01

    Nitromusks used as fragrances in a variety of personal-care products, cleansers, and domestic deodorants, including incense sticks, are neutral nitro aromatic compounds; some of these have been reported as photosensitizers. In this work, their analysis was performed by capillary electrophoresis (CE) in a methanol-based background electrolyte (BGE). In particular, a 10 mM solution of citric acid in methanol was used; under these conditions the strong suppression of the electroosmotic flow favored the use of negatively charged surfactants as additives for the anodic migration of the studied analytes. To this end, sodium taurodeoxycholate (TDC) was supplemented at high concentration (190 mM) to the organic background electrolyte (BGE), showing strong indication of the ability to give micelle-like aggregates. Since nitromusks are characterized by the presence of a nitroaromatic ring with low charge density, their association with TDC aggregates can be ascribed to donor-acceptor interactions. Separation of musk xylene, musk ketone, and the banned musk moskene and musk ambrette was obtained under full nonaqueous BGE; the addition of relatively small water percentages (15% v/v) was found to be useful in improving the separation of pairs of adjacent peaks. Under optimized conditions (190 mM sodium TDC in methanol-water, 85-15 v/v containing citric acid 10 mM) the system was applied to the analysis of nitromusks in incense sticks extracted with methanol. The results were compared with those obtained by the analysis of the same samples using gas chromatography with mass detector. The expected different selectivity of separation obtained using the two techniques can be useful in the unambiguous determination of the analytes; furthermore, a substantial accord of the preliminary quantitative results achieved with the two methods was assumed as the confirmation of the potential reliability of CE performed with high percentage of organic solvent.

  5. Effects of surface water on gas sorption capacities of gravimetric sensing layers analyzed by molecular descriptors of organic adsorbates.

    Science.gov (United States)

    Sugimoto, Iwao; Mitsui, Kouta; Nakamura, Masayuki; Seyama, Michiko

    2011-02-01

    The gas sorption capacities of sputtered carbonaceous films are evaluated with quartz crystal resonators. These films are sensitive to 20 ppm organic vapors and exhibit structure-dependent responses. Films derived from synthetic polymers are hydrophobic, whereas films derived from biomaterials are amphiphilic or hydrophilic. Polyethylene (PE) film has an extremely high sorption capacity for a wide range of vapors. Transient sorption responses are investigated using a humidified carrier by employing carboxylic acid esters, whose aliphatic groups are systematically changed. Small esters with a higher affinity to water induce negative U-shaped responses from amphiphilic films derived from biomaterials. On the other hand, polymeric films exhibit positive exponential response curves. Even if the concentrations are decreased, the response intensities are enhanced with the incremental expansion of carbon chains of aliphatic groups. Only fluoropolymer film shows the opposite tendency. The modeling of quantitative structure property relationships has indicated that the sorption capacities of the PE film to the carboxylic acid esters are fundamentally governed by electrostatic interactions. The intermolecular attractive forces are basically attributable to interactions between the positively polarized sites in esters and the negatively polarized/charged sites in PE film.

  6. Direct green waste land application: How to reduce its impacts on greenhouse gas and volatile organic compound emissions?

    Science.gov (United States)

    Zhu-Barker, Xia; Burger, Martin; Horwath, William R; Green, Peter G

    2016-06-01

    Direct land application as an alternative to green waste (GW) disposal in landfills or composting requires an understanding of its impacts on greenhouse gas (GHG) and volatile organic compound (VOC) emissions. We investigated the effects of two approaches of GW direct land application, surface application and soil incorporation, on carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), and VOC emissions for a 12month period. Five treatments were applied in fall 2013 on fallow land under a Mediterranean climate in California: 30cm height GW on surface; 15cm height GW on surface; 15cm height GW tilled into soil; control+till; control+no till. In addition, a laboratory experiment was conducted to develop a mechanistic understanding of the influence of GW application on soil O2 consumption and GHG emission. The annual cumulative N2O, CO2 and VOC emissions ranged from 1.6 to 5.5kgN2O-Nha(-1), 5.3 to 40.6MgCO2-Cha(-1) and 0.6 to 9.9kgVOCha(-1), respectively, and were greatly reduced by GW soil incorporation compared to surface application. Application of GW quickly consumed soil O2 within one day in the lab incubation. These results indicate that to reduce GHG and VOC emissions of GW direct land application, GW incorporation into soil is recommended.

  7. Identification of volatile organic compounds (VOCs in plastic products using gas chromatography and mass spectrometry (GC/MS

    Directory of Open Access Journals (Sweden)

    Nerlis Pajaro-Castro

    2014-10-01

    Full Text Available Plastic materials are widely used in daily life. They contain a wide range of compounds with low molecular mass, including monomeric and oligomeric residues of polymerization, solvent-related chemicals residues, and various additives. Plastic products made of expanded polystyrene (EPS are currently employed as food containers. This study therefore sought to identify volatile organic compounds released by EPS from food packages and utensils used in Cartagena, Colombia. EPS-based plates, food and soup containers were subjected to various temperatures and released chemicals captured by solid phase microextraction, followed by on-column thermal desorption and gas chromatography/mass spectrometry analysis. The results revealed the presence of at least 30 different compounds in the EPS-based products examined; the most frequently found were benzaldehyde, styrene, ethylbenzene and tetradecane. The release of these molecules was temperature-dependent. It is therefore advisable to regulate the use of EPS products which may be subjected to heating in order to protect human health by decreasing the exposure to these chemicals.

  8. Gas/vapour separation using ultra-microporous metal–organic frameworks: insights into the structure/separation relationship

    KAUST Repository

    Adil, Karim

    2017-05-30

    The separation of related molecules with similar physical/chemical properties is of prime industrial importance and practically entails a substantial energy penalty, typically necessitating the operation of energy-demanding low temperature fractional distillation techniques. Certainly research efforts, in academia and industry alike, are ongoing with the main aim to develop advanced functional porous materials to be adopted as adsorbents for the effective and energy-efficient separation of various important commodities. Of special interest is the subclass of metal-organic frameworks (MOFs) with pore aperture sizes below 5-7 Å, namely ultra-microporous MOFs, which in contrast to conventional zeolites and activated carbons show great prospects for addressing key challenges in separations pertaining to energy and environmental sustainability, specifically materials for carbon capture and separation of olefin/paraffin, acetylene/ethylene, linear/branched alkanes, xenon/krypton, etc. In this tutorial review we discuss the latest developments in ultra-microporous MOF adsorbents and their use as separating agents via thermodynamics and/or kinetics and molecular sieving. Appreciably, we provide insights into the distinct microscopic mechanisms governing the resultant separation performances, and suggest a plausible correlation between the inherent structural features/topology of MOFs and the associated gas/vapour separation performance.

  9. Volume shrinkage of a metal-organic framework host induced by the dispersive attraction of guest gas molecules.

    Science.gov (United States)

    Joo, Jaeyong; Kim, Hyungjun; Han, Sang Soo

    2013-11-21

    Using a density functional theory calculation including van der Waals (vdW) corrections, we report that H2 adsorption in a cubic-crystalline microporous metal-organic framework (MOF-5) leads to volume shrinkage, which is in contrast to the intuition that gas adsorption in a confined system (e.g., pores in a material) increases the internal pressure and then leads to volumetric expansion. This extraordinary phenomenon is closely related to the vdW interactions between MOF and H2 along with the H2-H2 interaction, rather than the Madelung-type electrostatic interaction. At low temperatures, H2 molecules adsorbed in the MOF-5 form highly symmetrical interlinked nanocages that change from a cube-like shape to a sphere-like shape with H2 loading, helping to exert centrosymmetric forces and hydrostatic (volumetric) stresses from the collection of dispersive interactions. The generated internal negative stress is sufficient to overcome the stiffness of the MOF-5 which is a soft material with a low bulk modulus (15.54 GPa).

  10. Full evaporation headspace gas chromatography for sensitive determination of high boiling point volatile organic compounds in low boiling matrices.

    Science.gov (United States)

    Mana Kialengila, Didi; Wolfs, Kris; Bugalama, John; Van Schepdael, Ann; Adams, Erwin

    2013-11-08

    Determination of volatile organic components (VOC's) is often done by static headspace gas chromatography as this technique is very robust and combines easy sample preparation with good selectivity and low detection limits. This technique is used nowadays in different applications which have in common that they have a dirty matrix which would be problematic in direct injection approaches. Headspace by nature favors the most volatile compounds, avoiding the less volatile to reach the injector and column. As a consequence, determination of a high boiling solvent in a lower boiling matrix becomes challenging. Determination of VOCs like: xylenes, cumene, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMA), N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), benzyl alcohol (BA) and anisole in water or water soluble products are an interesting example of the arising problems. In this work, a headspace variant called full evaporation technique is worked out and validated for the mentioned solvents. Detection limits below 0.1 μg/vial are reached with RSD values below 10%. Mean recovery values ranged from 92.5 to 110%. The optimized method was applied to determine residual DMSO in a water based cell culture and DMSO and DMA in tetracycline hydrochloride (a water soluble sample). Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Spatiotemporal dynamics of phosphorus release, oxygen consumption and greenhouse gas emissions after localised soil amendment with organic fertilisers

    Energy Technology Data Exchange (ETDEWEB)

    Christel, Wibke [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Department of Commerce, Industry and Agriculture, Danish Environmental Protection Agency, 1401 Copenhagen C (Denmark); Zhu, Kun [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Hoefer, Christoph [Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Kreuzeder, Andreas [Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Land Salzburg, Natur- und Umweltschutz, Gewerbe (Abteilung 5), Michael-Pacher-Straße 36, 5020 Salzburg (Austria); Santner, Jakob [Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Division of Agronomy, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Bruun, Sander; Magid, Jakob [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Jensen, Lars Stoumann, E-mail: lsj@plen.ku.dk [Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark)

    2016-06-01

    Organic fertilisation inevitably leads to heterogeneous distribution of organic matter and nutrients in soil, i.e. due to uneven surface spreading or inhomogeneous incorporation. The resulting localised hotspots of nutrient application will induce various biotic and abiotic nutrient turnover processes and fixation in the residuesphere, giving rise to distinct differences in nutrient availability, soil oxygen content and greenhouse gas (GHG) production. In this study we investigated the spatiotemporal dynamics of the reaction of manure solids and manure solids char with soil, focusing on their phosphorus (P) availability, as current emphasis on improving societal P efficiency through recycling waste or bio-based fertilisers necessitates a sound understanding of their behaviour. Soil layers amended at a constant P application rate with either pig manure solids or char made from pig manure solids were incubated for three weeks between layers of non-amended, P-depleted soil. Spatial and temporal changes in and around the amendment layers were simultaneously investigated in this study using a sandwich sensor consisting of a planar oxygen optode and multi-element diffusive gradients in thin films (DGT) gels, combined with GHG emission measurements. After three weeks of incubation, the soil containing a layer amended with manure solids had a lower overall O{sub 2} content and had emitted significantly more CO{sub 2} than the non-amended control or the char-amended soil. The P availability from manure solids was initially higher than that from the char, but decreased over time, whereas from the char-amended layer P availability increased in the same period. In both treatments, increases in P availability were confined to the amended soil layer and did not greatly affect P availability in the directly adjacent soil layers during the three-week incubation. These results highlight the importance of placing organic P fertilisers close to where the plant roots will grow in

  12. Characterization of oil source strata organic matter of Jurassic age and its contribution to the formation of oil and gas deposits

    Science.gov (United States)

    Pronin, Nikita; Nosova, Fidania; Plotnikova, Irina

    2013-04-01

    Within the frames of this work we carried out comprehensive geochemical study of high-carbon rocks samples taken from the three segments of the Jurassic system - from the lower (Kotuhtinskaya suite), from the medium (Tyumenskaya suite) and from the upper (Vasyuganskaya, Georgievskaya and the Bazhenovskaya suites), all within the north-eastern part of the Surgut oil and gas region. Altogether we investigated 27 samples. The complex study of the organic matter (OM) of these strata included the following: chloroform extraction of bitumen, the determination of the group and element composition, gas chromatography (GC) and gas chromatomass-spectrometry (GC/MS). These methods allow giving high quality assessments of the potential oil and gas source strata and thus identifying the possible oil and gas generating strata among them, ie, those strata that could be involved in the formation of oil and gas within the area. As a result of this work we identified various biomarkers that allow characterizing each oil and gas source strata under the study in the open-cast of the Jurassic system: 1. Kotuhtinskaya Suite. The build-up of this suite took place in the coastal marine weakly reducing conditions. In their composition these deposits contain some highly transformed humus organic matter (gradation of catagenesis MK3). 2. Tyumenskaya Suite. Accumulation of OM in these deposits occured mainly in the coastal marine environment with the influx of a large number of terrestrial vegetation in the basin of deposition. As for the type of agents - it is a humus or sapropel-humus OM with a rich content of continental organics. Source type of this OM is mixed - bacterial and algal. OM of the rocks of Tyumenskaya suite is situated in the area of high maturity (stage of catagenesis at MK3 level). 3. Vasyuganskaya Suite. In this case the accumulation of OM occurred mainly in the laguna (lake-delta) weak-reduction close to oxidative conditions with the influx of bacterial matter and the

  13. In-Situ observations of speciated organics in gas and particle phases: CalNex2010 Bakersfield and Los Angeles (Invited)

    Science.gov (United States)

    Goldstein, A. H.; Gentner, D. R.; Isaacman, G. A.; Worton, D. R.; Zhao, Y.; Weber, R.; Kreisberg, N. M.; Hering, S. V.; Williams, B. J.; Hohaus, T.; Jayne, J.; Lambe, A.; Williams, L. R.; Jimenez, J. L.; CalNex Bakersfield Science Team

    2010-12-01

    To identify the major sources and formation mechanisms of organic aerosol in polluted urban regions, we measured a wide range of gas phase and particle phase organics during the Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 experiment at the Bakersfield and Pasadena supersites. The CalNex supersites included an extensive array of co-located observations with cutting edge measurement technologies. This talk will highlight the observations of speciated organics and how they can be used to 1) identify the main emission sources linked with primary and secondary organic aerosol (SOA), 2) identify individual and classes of volatile and semivolatile organic compounds (VOCs and SVOCs) indicative of specific source categories and transformation processes, and 3) examine the gas/particle partitioning of specific SVOCs and the parameters which influence their uptake into SOA, such as meteorological (T, RH, etc), or chemical composition (aerosol organic carbon mass, aerosol acidity, etc.). The complex chemical composition of atmospheric aerosols, particularly the organic carbon portion, presents unique measurement challenges. We developed the Thermal Desorption Aerosol Gas chromatograph (TAG) system for hourly in-situ speciation of a wide range of primary and secondary species including alkanes, aldehydes, ketones, PAHs, monocarboxylic acids, and many more. Recently, we incorporated two-dimensional chromatography (GC×GC) into TAG (2DTAG) enhancing our chromatographic separation power by including polarity separation following volatility separation. We have also developed a combined TAG-AMS (Aerosol Mass Spectrometer) instrument for simultaneous measurements of the total and speciated aerosol composition. Observations reported from Bakersfield include ambient concentrations of ~250 species of VOCs measured hourly via in-situ gas chromatography containing 1-17 C atoms and a variety of functional groups (e.g. aldehydes, ketones, alcohols, halogens, sulfur

  14. SEM and FIB-SEM investigations on potential gas shales in the Dniepr-Donets Basin (Ukraine): pore space evolution in organic matter during thermal maturation

    Science.gov (United States)

    Misch, D.; Mendez-Martin, F.; Hawranek, G.; Onuk, P.; Gross, D.; Sachsenhofer, R. F.

    2016-02-01

    Porosity and permeability are essential parameters for reservoir rocks. Techniques developed for conventional reservoir rocks characterized by large pores, cannot be applied to study gas shales. Therefore, high resolution techniques are increasingly used to determine reservoir quality of shale gas plays. Within the frame of the recent study, Upper Visean black shales (“Rudov Beds”) from the Dniepr-Donets-Basin (DDB, Ukraine) were characterized by X-ray diffraction, conventional SEM imaging and FIB/BIB-SEM. According to SEM and FIB/BIB-SEM data, nanopores are not abundant in primary macerals (e.g., vitrinite) even in overmature rocks, whereas they develop within secondary organic matter (bitumen) formed mainly at gas window maturity. Frequently occurring sub-micrometre porosity, probably related to gas generation from bituminous organic matter, was detected within mudstones at a vitrinite reflectance > 2.0 % Rr. However, such pores have also been detected occasionally in solid bitumen at oil window maturity (0.9 % Rr). Authigenic nanoscale clay minerals and calcite occur within pyrobitumen at gas window maturity. Furthermore, Rudov Beds can be subdivided into mineralogical facies zones by SEM imaging and X-ray diffraction. A basin-centred, brittle siliceous facies is most likely caused by increased contribution from deeper water radiolaria and is separated from a marginal clayey and carbonate-rich facies.

  15. Simulating the detailed chemical composition of secondary organic aerosol formed on a regional scale during the TORCH 2003 campaign in the southern UK

    Directory of Open Access Journals (Sweden)

    D. Johnson

    2006-01-01

    Full Text Available Following on from the companion study (Johnson et al., 2006, a photochemical trajectory model (PTM has been used to simulate the chemical composition of organic aerosol for selected events during the 2003 TORCH (Tropospheric Organic Chemistry Experiment field campaign. The PTM incorporates the speciated emissions of 124 non-methane anthropogenic volatile organic compounds (VOC and three representative biogenic VOC, a highly-detailed representation of the atmospheric degradation of these VOC, the emission of primary organic aerosol (POA material and the formation of secondary organic aerosol (SOA material. SOA formation was represented by the transfer of semi- and non-volatile oxidation products from the gas-phase to a condensed organic aerosol-phase, according to estimated thermodynamic equilibrium phase-partitioning characteristics for around 2000 reaction products. After significantly scaling all phase-partitioning coefficients, and assuming a persistent background organic aerosol (both required in order to match the observed organic aerosol loadings, the detailed chemical composition of the simulated SOA has been investigated in terms of intermediate oxygenated species in the Master Chemical Mechanism, version 3.1 (MCM v3.1. For the various case studies considered, 90% of the simulated SOA mass comprises between ca. 70 and 100 multifunctional oxygenated species derived, in varying amounts, from the photooxidation of VOC of anthropogenic and biogenic origin. The anthropogenic contribution is dominated by aromatic hydrocarbons and the biogenic contribution by α- and β-pinene (which also constitute surrogates for other emitted monoterpene species. Sensitivity in the simulated mass of SOA to changes in the emission rates of anthropogenic and biogenic VOC has also been investigated for 11 case study events, and the results have been compared to the detailed chemical composition data. The role of accretion chemistry in SOA formation, and its

  16. Emission and chemistry of organic carbon in the gas and aerosol phase at a sub-urban site near Mexico City in March 2006 during the MILAGRO study

    Directory of Open Access Journals (Sweden)

    J. A. de Gouw

    2008-12-01

    Full Text Available Volatile organic compounds (VOCs and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives. Diurnal variations of hydrocarbons, elemental carbon (EC and hydrocarbon-like organic aerosol (HOA were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA and water-soluble organic carbon (WSOC stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the US, but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the US, due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the US. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC, and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps not

  17. Emission and Chemistry of Organic Carbon in the Gas and Aerosol Phase at a Sub-Urban Site Near Mexico City in March 2006 During the MILAGRO Study

    Energy Technology Data Exchange (ETDEWEB)

    de Gouw, Joost A.; Welsh-Bon, Daniel; Warneke, Carsten; Kuster, W. C.; Alexander, M. L.; Baker, Angela K.; Beyersdorf, Andreas J.; Blake, D. R.; Canagaratna, Manjula R.; Celada, A. T.; Huey, L. G.; Junkermann, W.; Onasch, Timothy B.; Salcido, A.; Sjostedt, S. J.; Sullivan, Amy; Tanner, David J.; Vargas-Ortiz, Leroy; Weber, R. J.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zaveri, Rahul A.

    2009-05-28

    Volatile organic compounds (VOCs) and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives). Diurnal variations of hydrocarbons, elemental carbon (EC) and hydrocarbon-like organic aerosol (HOA) were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA) and water-soluble organic carbon (WSOC) stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC), and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps not dissimilar

  18. Emission and chemistry of organic carbon in the gas and aerosol phase at a sub-urban site near Mexico City in March 2006 during the MILAGRO study

    Directory of Open Access Journals (Sweden)

    J. A. de Gouw

    2009-05-01

    Full Text Available Volatile organic compounds (VOCs and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives. Diurnal variations of hydrocarbons, elemental carbon (EC and hydrocarbon-like organic aerosol (HOA were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA and water-soluble organic carbon (WSOC stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC, and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps

  19. Gas-phase CO2 subtraction for improved measurements of the organic aerosol mass concentration and oxidation degree by an aerosol mass spectrometer.

    Science.gov (United States)

    Collier, S; Zhang, Q

    2013-12-17

    The Aerodyne aerosol mass spectrometer (AMS) has been widely used for real-time characterization of the size-resolved chemical composition of sub-micrometer aerosol particles. The first step in AMS sampling is the pre-concentration of aerosols while stripping away the gas-phase components, which contributes to the high sensitivity of this instrument. The strength of the instrument lies in particle phase measurement; however, ion signals generated from gas-phase species can influence the interpretation of the particle-phase chemistry data. Here, we present methods for subtracting the varying contributions of gas-phase carbon dioxide (CO2) in the AMS spectra of aerosol particles, which is critical for determining the mass concentration and oxygen-to-carbon (O/C) ratio of organic aerosol. This report gives details on the gaseous CO2 subtraction analysis performed on a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) data set acquired from sampling of fresh and diluted vehicle emissions. Three different methods were used: (1) collocated continuous gas-phase CO2 measurement coupled with periodic filter tests consisting of sampling the same particle-free air by the AMS and the CO2 analyzer, (2) positive matrix factorization (PMF) analysis to separate the gas- and particle-phase signals of CO2(+) at m/z 44, and (3) use of the particle time-of-flight (PTOF) size-resolved chemical information for separation of gas- and particle-phase signals at m/z 44. Our results indicate that these three different approaches yield internally consistent values for the gas/particle apportionment of m/z 44, but methods 2 and 3 require certain conditions to be met to yield reliable results. The methods presented are applicable to any situation where gas-phase components may influence the PM signal of interest.

  20. Analysis of volatile organic compounds in pleural effusions by headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry.

    Science.gov (United States)

    Huang, Zhongping; Zhang, Jie; Zhang, Peipei; Wang, Hong; Pan, Zaifa; Wang, Lili

    2016-07-01

    Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box-plot analysis showed that except for cyclohexanone, 2-ethyl-1-hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n-heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions.

  1. Estimation of emissions of nonmethane organic compounds from a closed landfill site using a landfill gas emission model

    Energy Technology Data Exchange (ETDEWEB)

    Nwachukwu, A.N. [Williamson Research Centre for Molecular Environmental Sciences, School of Earth, Atmospheric and Environmental Science, University of Manchester M13 9PL (United Kingdom); Diya, A.W. [Health Sciences Research Group, School of Medicine, University of Manchester M13 9PL (United Kingdom)

    2013-07-01

    Nonmethane organic compounds (NMOC) emissions from landfills often constitute significant risks both to human health and the general environment. To date very little work has been done on tracking the emissions of NMOC from landfills. To this end, a concerted effort was made to investigate the total annual mass emission rate of NMOC from a closed landfill site in South Manchester, United Kingdom. This was done by using field estimates of NMOC concentration and the landfill parameters into the Landfill Gas Emission Model embedded in ACTS and RISK software. Two results were obtained: (i) a deterministic outcome of 1.7218 x 10-7 kg/year, which was calculated from mean values of the field estimates of NMOC concentration and the landfill parameters, and (ii) a probabilistic outcome of 1.66 x 10-7 - 1.78 x 10-7 kg/year, which is a range of value obtained after Monte Carlo simulation of the uncertain parameters of the landfill including NMOC concentration. A comparison between these two results suggests that the probabilistic outcome is a more representative and reliable estimate of the total annual mass emission of NMOC especially given the variability of the parameters of the model. Moreover, a comparison of the model result and the safety standard of 5.0 x 10-5 kg/year indicate that the mass emission of NMOC from the studied landfill is significantly less than previously thought. However, given that this can accumulate to a dangerous level over a long period of time (such as the age of this landfill site); it may have started affecting the health of the people living within the vicinity of the landfill. A case is therefore made for more studies to be carried out on the emissions of other gases such as CH4 and CO2 from the studied landfill site, as this would help to understand the synergistic effect of the various gases being emitted from the landfill.

  2. Effects of London dispersion correction in density functional theory on the structures of organic molecules in the gas phase.

    Science.gov (United States)

    Grimme, Stefan; Steinmetz, Marc

    2013-10-14

    A benchmark set of 25 rotational constants measured in the gas phase for nine molecules (termed ROT25) was compiled from available experimental data. The medium-sized molecules with 18-35 atoms cover common (bio)organic structure motifs including hydrogen bonding and flexible side chains. They were each considered in a single conformation. The experimental B0 values were back-corrected to reference equilibrium rotational constants (Be) by computation of the vibrational corrections ΔBvib. Various density functional theory (DFT) methods and Hartree-Fock with and without dispersion corrections as well as MP2 type methods and semi-empirical quantum chemical approaches are investigated. The ROT25 benchmark tests their ability to describe covalent bond lengths, longer inter-atomic distances, and the relative orientation of functional groups (intramolecular non-covalent interactions). In general, dispersion corrections to DFT and HF increase Be values (shrink molecular size) significantly by about 0.5-1.5% thereby in general improving agreement with the reference data. Regarding DFT methods, the overall accuracy of the optimized structures roughly follows the 'Jacobs ladder' classification scheme, i.e., it decreases in the series double-hybrid > (meta)hybrid > (meta)GGA > LDA. With B2PLYP-D3, SCS-MP2, B3LYP-D3/NL, or PW6B95-D3 methods and extended QZVP (def2-TZVP) AO basis sets, Be values, accurate to about 0.3-0.6 (0.5-1)% on average, can be computed routinely. The accuracy of B2PLYP-D3/QZVP with a mean deviation of only 3 MHz and a standard deviation of 0.24% is exceptional and we recommend this method when highly accurate structures are required or for problematic conformer assignments. The correlation effects for three inter-atomic distance regimes (covalent, medium-range, long) and the performance of minimal basis set (semi-empirical) methods are discussed.

  3. Greenhouse gas performance of biochemical biodiesel production from straw: soil organic carbon changes and time-dependent climate impact.

    Science.gov (United States)

    Karlsson, Hanna; Ahlgren, Serina; Sandgren, Mats; Passoth, Volkmar; Wallberg, Ola; Hansson, Per-Anders

    2017-01-01

    Use of bio-based diesel is increasing in Europe. It is currently produced from oilseed crops, but can also be generated from lignocellulosic biomass such as straw. However, removing straw affects soil organic carbon (SOC), with potential consequences for the climate impact of the biofuel. This study assessed the climate impacts and energy balance of biodiesel production from straw using oleaginous yeast, with subsequent biogas production from the residues, with particular emphasis on SOC changes over time. It also explored the impact of four different scenarios for returning the lignin fraction of the biomass to soil to mitigate SOC changes. Climate impact was assessed using two methods, global warming potential (GWP) and a time-dependent temperature model (∆T s ) that describes changes in mean global surface temperature as a function of time or absolute temperature change potential (AGTP). Straw-derived biodiesel reduced GWP by 33-80% compared with fossil fuels and primary fossil energy use for biodiesel production was 0.33-0.80 MJprim/MJ, depending on the scenario studied. Simulations using the time-dependent temperature model showed that a scenario where all straw fractions were converted to energy carriers and no lignin was returned to soil resulted in the highest avoided climate impact. The SOC changes due to straw removal had a large impact on the results, both when using GWP and the time-dependent temperature model. In a climate perspective, it is preferable to combust straw lignin to produce electricity rather than returning it to the soil if the excess electricity replaces natural gas electricity, according to results from both GWP and time-dependent temperature modelling. Using different methods to assess climate impact did not change the ranking between the scenarios, but the time-dependent temperature model provided information about system behaviour over time that can be important for evaluation of biofuel systems, particularly in relation to

  4. Volatile organic compounds at two oil and natural gas production well pads in Colorado and Texas using passive samplers.

    Science.gov (United States)

    Eisele, Adam P; Mukerjee, Shaibal; Smith, Luther A; Thoma, Eben D; Whitaker, Donald A; Oliver, Karen D; Wu, Tai; Colon, Maribel; Alston, Lillian; Cousett, Tamira A; Miller, Michael C; Smith, Donald M; Stallings, Casson

    2016-04-01

    A pilot study was conducted in application of the U.S. Environmental Protection Agency (EPA) Methods 325A/B variant for monitoring volatile organic compounds (VOCs) near two oil and natural gas (ONG) production well pads in the Texas Barnett Shale formation and Colorado Denver-Julesburg Basin (DJB), along with a traffic-dominated site in downtown Denver, CO. As indicated in the EPA method, VOC concentrations were measured for 14-day sampling periods using passive-diffusive tube samplers with Carbopack X sorbent at fenceline perimeter and other locations. VOCs were significantly higher at the DJB well pad versus the Barnett well pad and were likely due to higher production levels at the DJB well pad during the study. Benzene and toluene were significantly higher at the DJB well pad versus downtown Denver. Except for perchloroethylene, VOCs measured at passive sampler locations (PSs) along the perimeter of the Barnett well pad were significantly higher than PSs farther away. At the DJB well pad, most VOC concentrations, except perchloroethylene, were significantly higher prior to operational changes than after these changes were made. Though limited, the results suggest passive samplers are precise (duplicate precision usually ≤10%) and that they can be useful to assess spatial gradients and operational conditions at well pad locations over time-integrated periods. Recently enacted EPA Methods 325A/B use passive-diffusive tube samplers to measure benzene at multiple fenceline locations at petrochemical refineries. This pilot study presents initial data demonstrating the utility of Methods 325A/B for monitoring at ONG facilities. Measurements revealed elevated concentrations reflective of production levels and spatial gradients of VOCs relative to source proximity at the Barnett well pad, as well as operational changes at the DJB well pad. Though limited, these findings indicate that Methods 325A/B can be useful in application to characterize VOCs at well pad

  5. Calculation of the Standard Molal Thermodynamic Properties of Crystalline, Liquid, and Gas Organic Molecules at High Temperatures and Pressures

    Science.gov (United States)

    Helgeson, Harold C.; Owens, Christine E.; Knox, Annette M.; Richard, Laurent

    1998-03-01

    Calculation of the thermodynamic properties of organic solids, liquids, and gases at high temperatures and pressures is a requisite for characterizing hydrothermal metastable equilibrium states involving these species and quantifying the chemical affinities of irreversible reactions of organic molecules in natural gas, crude oil, kerogen, and coal with minerals and organic, inorganic, and biomolecular aqueous species in interstitial waters in sedimentary basins. To facilitate calculations of this kind, coefficients for the Parameters From Group Contributions (PFGC) equation of state have been compiled for a variety of groups in organic liquids and gases. In addition, molecular weights, critical temperatures and pressures, densities at 25°C and 1 bar, transition, melting, and boiling temperatures ( Tt,Pr, Tm,Pr, and Tv,Pr, respectively) and standard molal enthalpies of transition (Δ H° t,Pr), melting (Δ H° m,Pr), and vaporization (Δ H° v,Pr) of organic species at 1 bar ( Pr) have been tabulated, together with an internally consistent and comprehensive set of standard molal Gibbs free energies and enthalpies of formation from the elements in their stable state at 298.15 K ( Tr) and Pr (Δ G° f and Δ H° f, respectively). The critical compilation also includes standard molal entropies ( S°) and volumes ( V°) at Tr and Pr, and standard molal heat capacity power function coefficients to compute the standard molal thermodynamic properties of organic solids, liquids, and gases as a function of temperature at 1 bar. These properties and coefficients have been tabulated for more than 500 crystalline solids, liquids, and gases, and those for many more can be computed from the equations of state group additivity algorithms. The crystalline species correspond to normal alkanes (C nH 2( n+1) ) with carbon numbers ( n, which is equal to the number of moles of carbon atoms in one mole of the species) ranging from 5 to 100, and 23 amino acids including glycine (C 2H 5NO

  6. Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2010-08-01

    Full Text Available Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008. This model allows the reliable computation of the liquid-liquid coexistence curve (binodal, corresponding tie-lines, the limit of stability/metastability (spinodal, and further thermodynamic properties of multicomponent systems. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six

  7. Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2010-05-01

    Full Text Available Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008. This model allows the reliable computation of the liquid-liquid coexistence curve (binodal, corresponding tie-lines, the limit of stability/metastability (spinodal, and further thermodynamic properties of the phase diagram. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six

  8. Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

    Science.gov (United States)

    Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

    2014-01-01

    Research on the effects of exposure of stream biota to complex mixtures of pharmaceuticals and other organic compounds associated with wastewater requires the development of additional analytical capabilities for these compounds in water samples. Two gas chromatography/mass spectrometry (GC/MS) analytical methods used at the U.S. Geological Survey National Water Quality Laboratory (NWQL) to analyze organic compounds associated with wastewater were adapted to include additional pharmaceutical and other organic compounds beginning in 2009. This report includes a description of method performance for 42 additional compounds for the filtered-water method (hereafter referred to as the filtered method) and 46 additional compounds for the unfiltered-water method (hereafter referred to as the unfiltered method). The method performance for the filtered method described in this report has been published for seven of these compounds; however, the addition of several other compounds to the filtered method and the addition of the compounds to the unfiltered method resulted in the need to document method performance for both of the modified methods. Most of these added compounds are pharmaceuticals or pharmaceutical degradates, although two nonpharmaceutical compounds are included in each method. The main pharmaceutical compound classes added to the two modified methods include muscle relaxants, opiates, analgesics, and sedatives. These types of compounds were added to the original filtered and unfiltered methods largely in response to the tentative identification of a wide range of pharmaceutical and other organic compounds in samples collected from wastewater-treatment plants. Filtered water samples are extracted by vacuum through disposable solid-phase cartridges that contain modified polystyrene-divinylbenzene resin. Unfiltered samples are extracted by using continuous liquid-liquid extraction with dichloromethane. The compounds of interest for filtered and unfiltered sample

  9. The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method.

    Science.gov (United States)

    Wada, Takao; Ueda, Noriaki

    2013-04-21

    The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature.

  10. Development of a parallel sampling and analysis method for the elucidation of gas/particle partitioning of oxygenated semi-volatile organics: a limonene ozonolysis study

    Directory of Open Access Journals (Sweden)

    S. Rossignol

    2012-06-01

    Full Text Available The gas/particle partitioning behaviour of the semi-volatile fraction of secondary organic matter and the associated multiphase chemistry are key features to accurately evaluate climate and health impacts of secondary organic aerosol (SOA. However, today, the partitioning of oxygenated secondary species is rarely assessed in experimental SOA studies and SOA modelling is still largely based on estimated partitioning data. This paper describes a new analytical approach, solvent-free and easy to use, to explore the chemical composition of the secondary organic matter at a molecular scale in both gas and particulate phases. The method is based on thermal desorption (TD of gas and particulate samples, coupled with gas chromatography (GC and mass spectrometry (MS, with derivatisation on sampling supports. Gaseous compounds were trapped on Tenax TA adsorbent tubes pre-coated with pentafluorobenzylhydroxylamine (PFBHA or N-Methyl-N-(t-butyldimethylsilyltrifluoroacetamide (MTBSTFA. Particulate samples were collected onto quartz or Teflon-quartz filters and subsequently subjected to derivatisation with PFBHA or MTBSTFA before TD-GC/MS analysis. Method development and validation are presented for an atmospherically relevant range of organic acids and carbonyl and hydroxyl compounds. Application of the method to a limonene ozonolysis experiment conducted in the EUPHORE simulation chamber under simulated atmospheric conditions of low concentrations of limonene precursor and relative humidity, provides an overview of the method capabilities. Twenty-five compounds were positively or tentatively identified, nine being in both gaseous and particulate phases; and twelve, among them tricarboxylic acids, hydroxyl dicarboxylic acids and oxodicarboxylic acids, being detected for the first time.

  11. Semicontinuous measurements of gas-particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    Science.gov (United States)

    Yatavelli, R. L. N.; Stark, H.; Thompson, S. L.; Kimmel, J. R.; Cubison, M. J.; Day, D. A.; Campuzano-Jost, P.; Palm, B. B.; Hodzic, A.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2014-02-01

    Hundreds of gas- and particle-phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen - Rocky Mountain Biogenic Aerosol Study). A recently developed micro-orifice volatilization impactor high-resolution time-of-flight chemical ionization mass spectrometer (MOVI-HRToF-CIMS) using acetate (CH3C(O)O-) as the reagent ion was used to selectively ionize and detect acids semicontinuously from 20 to 30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas phase, with only ~2% in the particle phase. We investigated gas-particle partitioning, quantified as the fraction in the particle phase (Fp), of C1-C18 alkanoic acids, six known terpenoic acids, and bulk organic acids vs. carbon number. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1-2 h) of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show poor agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Partitioning to the aqueous phase is predicted to be smaller than to the organic phase for alkanoic and bulk acids, and has different trends with time and carbon number than observed experimentally. This is due

  12. Determination of heat purgeable and ambient purgeable volatile organic compounds in water by gas chromatography/mass spectrometry

    Science.gov (United States)

    Rose, Donna L.; Sandstrom, Mark W.; Murtagh, Lucinda K.

    2016-09-08

    Two new analytical methods have been developed by the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) that allow the determination of 37 heat purgeable volatile organic compounds (VOCs) (USGS Method O-4437-16 [NWQL Laboratory Schedule (LS) 4437]) and 49 ambient purgeable VOCs (USGS Method O-4436-16 [NWQL LS 4436]) in unfiltered water. This report documents the procedures and initial performance of both methods. The compounds chosen for inclusion in the methods were determined as having high priority by the USGS National Water-Quality Assessment (NAWQA) Program. Both methods use a purge-and-trap technique with gas chromatography/mass spectrometry. The compounds are extracted from the sample by bubbling helium through a 25-milliliter sample. For the polar and less volatile compounds, the sample is heated at 60 degrees Celsius, whereas the less polar and more volatile compounds are purged using a separate analytical procedure at ambient temperature. The compounds are trapped on a sorbent trap, desorbed into a gas chromatograph/mass spectrometer for separation, and then identified and quantified. Sample preservation is recommended for both methods by adding a 1:1 solution of hydrochloric acid (HCl [1:1]) to water samples to adjust the pH to 2. Analysis within 14 days from sampling is recommended.The heat purgeable method (USGS Method O-4437-16) operates with the mass spectrometer in the simultaneous full scan/selected ion monitoring mode. This method supersedes USGS Method O-4024-03 (NWQL LS 4024). Method detection limits (MDLs) for fumigant compounds 1,2-dibromoethane, 1,2-dichloropropane, 1,2,3-trichloropropane, chloropicrin, and 1,2-dibromo-3-chloropropane range from 0.002 to 0.010 microgram per liter (µg/L). The MDLs for all remaining heat purgeable VOCs range from 0.006 µg/L for tert-butyl methyl ether to 3 µg/L for alpha-terpineol. Calculated holding times indicate that 36 of the 37 heat purgeable VOCs are stable for a minimum of 14 days

  13. Ozone Precursor Trends in Colorado and Their Relevance to Oil and Gas Development

    Science.gov (United States)

    Pierce, G. E.; Frazier, A. C.

    2015-12-01

    Oil and gas development has occurred in Colorado for over 150 years. With the increasing use of horizontal drilling and hydraulic fracturing, development of shale oil resources has increased significantly during the past ten years. One of the areas is the Denver-Julesburg (D-J) Basin in northeast Colorado, where there are now over 20,000 active wells. The North Front Range area of Colorado, including Denver, is a non-attainment area for ozone, where emissions from oil and gas development in the D-J Basin are a major concern. If a lower ozone standard is promulgated by EPA, other areas of Colorado will likely be designated as non-attainment as well. Colorado has instituted a number of regulations on the oil and gas industry over the past decade to help reduce emissions. The Denver metropolitan area has also grown significantly over the past decades to a population of over 2.6 million, which adds an urban component to the mix of ozone precursor emissions. Ambient monitoring of ozone precursors, including non-methane organic compounds and carbonyls, has been performed at a number of locations in the North Front Range area of Colorado over the past 12 years. Two of these sites have been in continuous operation since 2012; one site is located in the core of the city of Denver, while the other is located in the center of the oil and gas development area and has recorded high levels of ethane. Additionally, air monitoring sites operating on the western slope of Colorado that includes the Piceance Basin have data as far back as 2004. We present trends from the ozone precursor monitoring conducted in Colorado, and discuss how these precursors may contribute to ozone formation, particularly those related to oil and gas development. These data are valuable for emissions inventory work and model validation related to upcoming State Implementation Plans for ozone. The data will also be used in association with the 2014 Front Range Air Pollution and Photochemistry Experiment

  14. Naturally driven variability in the global secondary organic aerosol over a decade

    Directory of Open Access Journals (Sweden)

    K. Tsigaridis

    2005-01-01

    Full Text Available In order to investigate the variability of the secondary organic aerosol (SOA distributions and budget and provide a measure for the robustness of the conclusions on human induced changes of SOA, a global 3-dimensional chemistry transport model describing both the gas and the particulate phase chemistry of the troposphere has been applied. The response of the global budget of SOA to temperature and moisture changes as well as to biogenic emission changes over a decade (1984-1993 has been evaluated. The considered emissions of biogenic non-methane volatile organic compounds (VOC are driven by temperature, light and vegetation. They vary between 756 and 810 Tg Cy-1 and are therefore about 5.5 times higher than the anthropogenic VOC emissions. All secondary aerosols (sulphuric, nitrates and organics are computed on-line together with the aerosol associated water. Over the studied decade, the computed natural variations (8% in the chemical SOA production from biogenic VOC oxidation equal the chemical SOA production from anthropogenic VOC oxidation. Maximum values are calculated for 1990 (warmer and drier and minimum values for 1986 (colder and wetter. The SOA computed variability results from a 7% increase in biogenic VOC emissions from 1986 to 1990 combined with 8.5% and 6% increases in the wet and dry deposition of SOA and leads to about 11.5% increase in the SOA burden of biogenic origin. The present study also demonstrates the importance of the hydrological cycle in determining the built up and fate of SOA in the atmosphere. It also reveals the existence of significant positive and negative feedback mechanisms in the atmosphere responsible for the non linear relationship between emissions of biogenic VOC and SOA burden.

  15. Naturally driven variability in the global secondary organic aerosol over a decade

    Directory of Open Access Journals (Sweden)

    K. Tsigaridis

    2005-03-01

    Full Text Available In order to investigate the variability of the secondary organic aerosol (SOA distributions and budget and provide a measure for the robustness of the conclusions on human induced changes of SOA, a global 3-dimensional chemistry transport model describing both the gas and the particulate phase chemistry of the troposphere has been applied. The response of the global budget of SOA to temperature and moisture changes as well as to biogenic emission changes over a decade (1984–1993 has been evaluated. The considered emissions of biogenic non-methane volatile organic compounds (VOC are driven by temperature, light and vegetation. They vary between 756 and 810 TgC y-1 and are therefore about 5.5 times higher than the anthropogenic VOC emissions. All secondary aerosols (sulphuric, nitrates and organics are computed on-line together with the aerosol associated water. Over the studied decade, the computed natural variations (8% in the chemical SOA production from biogenic VOC oxidation equal the chemical SOA production from anthropogenic VOC oxidation. This computed variability results from a 7% increase in biogenic VOC emissions combined with 8.5% and 6% increases in the wet and dry deposition of SOA and leads to about 11.5% increase in the SOA burden of biogenic origin. The present study also demonstrates the importance of the hydrological cycle in determining the built up and fate of SOA in the atmosphere. It also reveals the existence of significant positive and negative feedback mechanisms in the atmosphere responsible for the non linear relationship between emissions of biogenic VOC and SOA burden.

  16. Estimation of emissions of nonmethane organic compounds from a closed landfill site using a landfill gas emission model

    Directory of Open Access Journals (Sweden)

    A. N. Nwachukwu, A. W. Diya

    2013-01-01

    Full Text Available Nonmethane organic compounds (NMOC emissions from landfills often constitute significant risks both to human health and the general environment. To date very little work has been done on tracking the emissions of NMOC from landfills. To this end, a concerted effort was made to investigate the total annual mass emission rate of NMOC from a closed landfill site in South Manchester, United Kingdom. This was done by using field estimates of NMOC concentration and the landfill parameters into the Landfill Gas Emission Model embedded in ACTS and RISK software. Two results were obtained: (i a deterministic outcome of 1.7218 x 10-7 kg/year, which was calculated from mean values of the field estimates of NMOC concentration and the landfill parameters, and (ii a probabilistic outcome of 1.66 x 10-7 - 1.78 x 10-7 kg/year, which is a range of value obtained after Monte Carlo simulation of the uncertain parameters of the landfill including NMOC concentration. A comparison between these two results suggests that the probabilistic outcome is a more representative and reliable estimate of the total annual mass emission of NMOC especially given the variability of the parameters of the model. Moreover, a comparison of the model result and the safety standard of 5.0 x 10-5 kg/year indicate that the mass emission of NMOC from the studied landfill is significantly less than previously thought. However, given that this can accumulate to a dangerous level over a long period of time (such as the age of this landfill site; it may have started affecting the health of the people living within the vicinity of the landfill. A case is therefore made for more studies to be carried out on the emissions of other gases such as CH4 and CO2 from the studied landfill site, as this would help to understand the synergistic effect of the various gases being emitted from the landfill.

  17. Trace Atmospheric Gas Analyzer (TAGA) Volatile Organic Compound (VOC) Data for BP Spill/Deepwater Horizon - August 2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Trace Atmospheric Gas Analyzer (TAGA) buses are self-contained mobile laboratories that conduct instant-result monitoring of air quality at particular locations....

  18. Trace Atmospheric Gas Analyzer (TAGA) Volatile Organic Compound (VOC) Data for BP Spill/Deepwater Horizon - July 2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Trace Atmospheric Gas Analyzer (TAGA) buses are self-contained mobile laboratories that conduct instant-result monitoring of air quality at particular locations....

  19. Trace Atmospheric Gas Analyzer (TAGA) Volatile Organic Compound (VOC) Data for BP Spill/Deepwater Horizon - May 2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Trace Atmospheric Gas Analyzer (TAGA) buses are self-contained mobile laboratories that conduct instant-result monitoring of air quality at particular locations....

  20. Trace Atmospheric Gas Analyzer (TAGA) Volatile Organic Compound (VOC) Data for BP Spill/Deepwater Horizon - June 2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Trace Atmospheric Gas Analyzer (TAGA) buses are self-contained mobile laboratories that conduct instant-result monitoring of air quality at particular locations....

  1. Semi-continuous measurements of gas/particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    Science.gov (United States)

    Yatavelli, R. L. N.; Stark, H.; Thompson, S. L.; Kimmel, J. R.; Cubison, M. J.; Day, D. A.; Campuzano-Jost, P.; Palm, B. B.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2013-06-01

    Hundreds of gas and particle phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen - Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS). A recently developed Micro-Orifice Volatilization Impactor High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (MOVI-HRToF-CIMS) using acetate (CH3C(O)O-) as the reagent ion was used to selectively ionize and detect acids semi-continuously from 20-30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas-phase, with only ~2% in the particle phase. We investigated gas/particle partitioning, quantified as the fraction in the particle phase (Fp), of C1-C18 alkanoic acids, six known terpenoic acids and total bulk organic acids. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1-2 h) of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show agreement on trends, but poor absolute agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Based on measurement-model comparison we conclude that species carbon number and oxygen content, together with ambient temperature control the volatility of organic acids and are good

  2. Semi-continuous measurements of gas/particle partitioning of organic acids in a ponderosa pine forest using a MOVI-HRToF-CIMS

    Directory of Open Access Journals (Sweden)

    R. L. N. Yatavelli

    2013-06-01

    Full Text Available Hundreds of gas and particle phase organic acids were measured in a rural ponderosa pine forest in Colorado, USA, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen – Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS. A recently developed Micro-Orifice Volatilization Impactor High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (MOVI-HRToF-CIMS using acetate (CH3C(OO- as the reagent ion was used to selectively ionize and detect acids semi-continuously from 20–30 August 2011, with a measurement time resolution of ~1.5 h. At this site 98% of the organic acid mass is estimated to be in the gas-phase, with only ~2% in the particle phase. We investigated gas/particle partitioning, quantified as the fraction in the particle phase (Fp, of C1–C18 alkanoic acids, six known terpenoic acids and total bulk organic acids. Data were compared to the absorptive partitioning model and suggest that bulk organic acids at this site follow absorptive partitioning to the organic aerosol mass. The rapid response (<1–2 h of partitioning to temperature changes for bulk acids suggests that kinetic limitations to equilibrium are minor, which is in contrast to conclusions of some recent laboratory and field studies, possibly due to lack of very low ambient relative humidities at this site. Time trends for partitioning of individual and groups of acids were mostly captured by the model, with varying degrees of absolute agreement. Species with predicted substantial fractions in both the gas and particle phases show better absolute agreement, while species with very low predicted fractions in one phase often show agreement on trends, but poor absolute agreement, potentially due to thermal decomposition, inlet adsorption, or other issues. Based on measurement-model comparison we conclude that species carbon number and oxygen content, together with ambient temperature control the volatility of organic

  3. Greenhouse gas (GHG) emission in organic farming. Approximate quantification of its generation at the organic garden of the School of Agricultural, Food and Biosystems Engineering (ETSIAAB) in the Technical University of Madrid (UPM)

    Science.gov (United States)

    Campos, Jorge; Barbado, Elena; Maldonado, Mariano; Andreu, Gemma; López de Fuentes, Pilar

    2016-04-01

    As it well-known, agricultural soil fertilization increases the rate of greenhouse gas (GHG) emission production such as CO2, CH4 and N2O. Participation share of this activity on the climate change is currently under study, as well as the mitigation possibilities. In this context, we considered that it would be interesting to know how this share is in the case of organic farming. In relation to this, a field experiment was carried out at the organic garden of the School of Agricultural, Food and Biosystems Engineering (ETSIAAB) in the Technical University of Madrid (UPM). The orchard included different management growing areas, corresponding to different schools of organic farming. Soil and gas samples were taken from these different sites. Gas samples were collected throughout the growing season from an accumulated atmosphere inside static chambers inserted into the soil. Then, these samples were carried to the laboratory and there analyzed. The results obtained allow knowing approximately how ecological fertilization contributes to air pollution due to greenhouse gases.

  4. The ability of microbial community of Lake Baikal bottom sediments associated with gas discharge to carry out the transformation of organic matter under thermobaric conditions

    Directory of Open Access Journals (Sweden)

    Sergei Viktorovich Bukin

    2016-05-01

    Full Text Available The ability to compare the composition and metabolic potential of microbial communities inhabiting the subsurface sediment in geographically distinct locations is one of the keys to understanding the evolution and function of the subsurface biosphere. Prospective areas for study of the subsurface biosphere are the sites of hydrocarbon discharges on the bottom of the Lake Baikal rift, where ascending fluxes of gas-saturated fluids and oil from deep layers of bottom sediments seep into near-surface sediment. The samples of surface sediments collected in the area of the Posolskaya Bank methane seep were cultured for 17 months under thermobaric conditions (80°С, 5 MPa with the addition of complementary organic substrate, and a different composition for the gas phase. After incubation, the presence of intact cells of microorganisms, organic matter transformation and the formation of oil biomarkers was confirmed in the samples, with the addition of Baikalian diatom alga Synedra acus detritus, and gas mixture СH4:H2:CO2. Taxonomic assignment of the 16S rRNA sequence data indicates that the predominant sequences in the enrichment were Sphingomonas (55.3%, Solirubrobacter (27.5% and Arthrobacter (16.6%. At the same time, in heat-killed sediment and in sediment without any additional substrates, which were cultivated in a CH4 atmosphere, no geochemical changes were detected, nor the presence of intact cells and 16S rRNA sequences of Bacteria and Archaea. This data may suggest that the decomposition of organic matter under culturing conditions could be performed by microorganisms from low-temperature sediment layers. One possible explanation of this phenomenon is migration of the representatives of the deep thermophilic community through fault zones in the near surface sediment layers, together with gas-bearing fluids.

  5. Effects of some organic acids and salts on microbial fermentation in the digestive tract of piglets estimated using an in vitro gas production technique

    Directory of Open Access Journals (Sweden)

    K. PARTANEN

    2008-12-01

    Full Text Available An in vitro gas production technique was used to screen different organic acids (formic, propionic, lactic, citric, and fumaric acid, organic salts (calcium formate, potassium sorbate, and sodium benzoate, and inorganic phosphoric acid for their ability to modulate microbial fermentation in the digestive tract of piglets. For the incubation, 40 ml of culture medium (53% buffer, 45% frozen ileal digesta, and 2% fresh faeces was dispensed in vessels containing 5 ml of buffer, 0.5 g of feed, and 20 ìl of liquid or 20 mg of solid acidifiers. Gas production was measured every 15 min during the 24 h incubation at 39°C, and a Gompertz bacterial growth model was applied to the gas production data. Formic acid was the only acid that reduced the maximum rate of gas production (ìm compared to that in the control treatment (P 0.05. When investigating formic-acid-based mixtures that contained 1–5% of potassium sorbate and/or sodium benzoate, the estimated parameters for the Gompertz growth model did not differ from those for treatments with plain formic acid (P > 0.05. However, concentrations of total volatile fatty acids, acetic acid, propionic acid, and n-butyric acid were reduced by all the mixtures (P 0.05. In conclusion, organic acids and salts were found to differ in their ability to modulate microbial fermentation in the digestive tract of piglets. Mixing formic acid with potassium sorbate or sodium benzoate changed fermentation patterns, and the possibility to use them to enhance the antimicrobial effect of formic acid should be investigated further in vivo.;

  6. The Ability of Microbial Community of Lake Baikal Bottom Sediments Associated with Gas Discharge to Carry Out the Transformation of Organic Matter under Thermobaric Conditions.

    Science.gov (United States)

    Bukin, Sergei V; Pavlova, Olga N; Manakov, Andrei Y; Kostyreva, Elena A; Chernitsyna, Svetlana M; Mamaeva, Elena V; Pogodaeva, Tatyana V; Zemskaya, Tamara I

    2016-01-01

    The ability to compare the composition and metabolic potential of microbial communities inhabiting the subsurface sediment in geographically distinct locations is one of the keys to understanding the evolution and function of the subsurface biosphere. Prospective areas for study of the subsurface biosphere are the sites of hydrocarbon discharges on the bottom of the Lake Baikal rift, where ascending fluxes of gas-saturated fluids and oil from deep layers of bottom sediments seep into near-surface sediment. The samples of surface sediments collected in the area of the Posolskaya Bank methane seep were cultured for 17 months under thermobaric conditions (80°C, 5 MPa) with the addition of complementary organic substrate, and a different composition for the gas phase. After incubation, the presence of intact cells of microorganisms, organic matter transformation and the formation of oil biomarkers was confirmed in the samples, with the addition of Baikal diatom alga Synedra acus detritus, and gas mixture CH4:H2:CO2. Taxonomic assignment of the 16S rRNA sequence data indicates that the predominant sequences in the enrichment were Sphingomonas (55.3%), Solirubrobacter (27.5%) and Arthrobacter (16.6%). At the same time, in heat-killed sediment and in sediment without any additional substrates, which were cultivated in a CH4 atmosphere, no geochemical changes were detected, nor the presence of intact cells and 16S rRNA sequences of Bacteria and Archaea. This data may suggest that the decomposition of organic matter under culturing conditions could be performed by microorganisms from low-temperature sediment layers. One possible explanation of this phenomenon is migration of the representatives of the deep thermophilic community through fault zones in the near surface sediment layers, together with gas-bearing fluids.

  7. Nanophase Carbonates on Mars: Does Evolved Gas Analysis of Nanophase Carbonates Reveal a Large Organic Carbon Budget in Near-Surface Martian Materials?

    Science.gov (United States)

    Archer, P. Douglas, Jr.; Niles, Paul B.; Ming, Douglas W.; Sutter, Brad; Eigenbrode, Jen

    2015-01-01

    Evolved Gas Analysis (EGA), which involves heating a sample and monitoring the gases released, has been performed on Mars by the Viking gas chromatography/mass spectrometry instruments, the Thermal and Evolved Gas Analyzer (TEGA) on the Phoenix lander, and the Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory. All of these instruments detected CO2 released during sample analysis at abundances of approx. 0.1 to 5 wt% assuming a carbonate source. The source of the CO2 can be constrained by evaluating the temperature of the gas release, a capability of both the TEGA and SAM instruments. The samples analyzed by SAM show that the majority of the CO2 is released below 400C, much lower than traditional carbonate decomposition temperatures which can be as low as 400C for some siderites, with magnesites and calcites decomposing at even higher temperatures. In addition to mineralogy, decomposition temperature can depend on particle size (among other factors). If carbonates formed on Mars under low temperature and relative humidity conditions, the resulting small particle size (nanophase) carbonates could have low decomposition temperatures. We have found that calcite can be synthesized by exposing CaO to water vapor and CO2 and that the resulting mineral has an EGA peak of approx. 550C for CO2, which is about 200C lower than for other calcites. Work is ongoing to produce Fe and Mg-bearing carbonates using the same process. Current results suggest that nanophase calcium carbonates cannot explain the CO2 released from martian samples. If the decomposition temperatures of Mg and Fe-bearing nanophase carbonates are not significantly lower than 400C, other candidate sources include oxalates and carboxylated organic molecules. If present, the abundance of organic carbon in these samples could be greater than 0.1 wt % (1000s of ppm), a signficant departure from the paradigm of the organic-poor Mars based on Viking results.

  8. Nanophase Carbonates on Mars: Does Evolved Gas Analysis of Nanophase Carbonates Reveal a Large Organic Carbon Budget in Near-surface Martian Materials?

    Science.gov (United States)

    Archer, P. D., Jr.; Ming, D. W.; Sutter, B.; Niles, P. B.; Eigenbrode, J. L.

    2015-12-01

    Evolved Gas Analysis (EGA), which involves heating a sample and monitoring the gases released, has been performed on Mars by the Viking gas chromatography/mass spectrometry instruments, the Thermal and Evolved Gas Analyzer (TEGA) on the Phoenix lander, and the Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory. All of these instruments detected CO2 released during sample analysis at abundances of ~0.1 to 5 wt% assuming a carbonate source. The source of the CO2 can be constrained by evaluating the temperature of the gas release, a capability of both the TEGA and SAM instruments. The samples analyzed by SAM show that the majority of the CO2is released below 400 °C, much lower than traditional carbonate decomposition temperatures which can be as low as 400 °C for some siderites, with magnesites and calcites decomposing at even higher temperatures. In addition to mineralogy, decomposition temperature can depend on particle size (among other factors). If carbonates formed on Mars under low temperature and relative humidity conditions, the resultin