Frequency–amplitude range of hydrocarbon microtremors and a discussion on their source

International Nuclear Information System (INIS)

Gerivani, H; Hafezi Moghaddas, N; Ghafoori, M; Lashkaripour, G R; Haghshenas, E

2012-01-01

Recently, some studies have suggested using ambient noise as a tool for hydrocarbon reservoir investigation. This new passive seismic technique, named HyMas, is based on the positive energy anomaly in data spectra between 1 to 6 Hz for microtremor measurements over reservoirs, which are called hydrocarbon microtremors. Despite the acceptable results obtained by the HyMas technique, there are many unknowns, especially concerning the source and generation mechanism of hydrocarbon microtremors and the relations between reservoir characteristics and the attributes of hydrocarbon microtremors. In this study we tried to find the relations between reservoir characteristics, including fluid content and depth, for 12 sites around the world with hydrocarbon microtremor attributes, including peak amplitude and frequency. Based on the power spectral density curves of these 12 reservoirs, a frequency–amplitude range is also proposed as a criterion for separating hydrocarbon microtremors from local noise not related to reservoirs. Finally, the source of the hydrocarbon microtremors is discussed and tidal displacement is suggested as a probable agent for the generation of these anomalies. (paper)

Total organic carbon, an important tool in a holistic approach to hydrocarbon source fingerprinting

International Nuclear Information System (INIS)

Boehm, P.D.; Burns, W.A.; Page, D.S.; Bence, A.E.; Mankiewicz, P.J.; Brown, J.S.; Douglas, G.S.

2002-01-01

Total organic carbon (TOC) was used to verify the consistency of source allocation results for the natural petrogenic hydrocarbon background of the northern Gulf of Alaska and Prince William Sound where the Exxon Valdez oil spill occurred in 1998. The samples used in the study were either pre-spill sediments or from the seafloor outside the spill path. It is assumed that the natural petrogenic hydrocarbon background in the area comes from either seep oil residues and shale erosion including erosion from petroleum source rock shales, or from coals including those of the Bering River coalfields. The objective of this study was to use the TOC calculations to discriminate between the two very different sources. TOC can constrain the contributions of specific sources and rule out incorrect source allocations, particularly when inputs are dominated by fossil organic carbon. The benthic sediments used in this study showed excellent agreement between measured TOC and calculated TOC from hydrocarbon fingerprint matches of polycyclic aromatic hydrocarbons (PAH) and chemical biomarkers. TOC and fingerprint matches confirmed that TOC sources were properly identified. The matches quantify the hydrocarbon contributions of different sources to the benthic sediments and the degree of hydrocarbon winnowing by waves and currents. It was concluded that the natural petrogenic hydrocarbon background in the sediments in the area comes from eroding Tertiary shales and oil seeps along the northern Gulf of Alaska coast. Thermally mature area coals are excluded from being important contributors to the background at Prince William Sound because of their high TOC content. 26 refs., 4 figs

Total organic carbon, an important tool in a holistic approach to hydrocarbon source fingerprinting

Energy Technology Data Exchange (ETDEWEB)

Boehm, P.D. [Battelle, Waltham, MA (United States); Burns, W.A. [W.A. Burns Consulting Services, Houston, TX (United States); Page, D.S. [Bowdoin College, Brunswick, ME (United States); Bence, A.E.; Mankiewicz, P.J. [ExxonMobil Upstream Research Co., Houston, TX (United States); Brown, J.S.; Douglas, G.S. [Battelle, Duxbury, MA (United States)

2002-07-01

Total organic carbon (TOC) was used to verify the consistency of source allocation results for the natural petrogenic hydrocarbon background of the northern Gulf of Alaska and Prince William Sound where the Exxon Valdez oil spill occurred in 1998. The samples used in the study were either pre-spill sediments or from the seafloor outside the spill path. It is assumed that the natural petrogenic hydrocarbon background in the area comes from either seep oil residues and shale erosion including erosion from petroleum source rock shales, or from coals including those of the Bering River coalfields. The objective of this study was to use the TOC calculations to discriminate between the two very different sources. TOC can constrain the contributions of specific sources and rule out incorrect source allocations, particularly when inputs are dominated by fossil organic carbon. The benthic sediments used in this study showed excellent agreement between measured TOC and calculated TOC from hydrocarbon fingerprint matches of polycyclic aromatic hydrocarbons (PAH) and chemical biomarkers. TOC and fingerprint matches confirmed that TOC sources were properly identified. The matches quantify the hydrocarbon contributions of different sources to the benthic sediments and the degree of hydrocarbon winnowing by waves and currents. It was concluded that the natural petrogenic hydrocarbon background in the sediments in the area comes from eroding Tertiary shales and oil seeps along the northern Gulf of Alaska coast. Thermally mature area coals are excluded from being important contributors to the background at Prince William Sound because of their high TOC content. 26 refs., 4 figs.

Process for producing volatile hydrocarbons from hydrocarbonaceous solids

Energy Technology Data Exchange (ETDEWEB)

1949-02-03

In a process for producing volatile hydrocarbons from hydrocarbonaceous solids, a hydrocarbonaceus solid is passed in subdivided state and in the form of a bed downwardly through an externally unheated distilling retort wherein the evolution of volatiles from the bed is effected while solid material comprising combustible heavy residue is discharged from the lower portion of the bed and retort, combustibles are burned from the discharged solid material. The admixture resultant combustion gases with the vapours evolved in the retort is prevented, and a stream of hydrocarbon fluid is heated by indirect heat exchange with hot combustion gases produced by burning to a high temperature and is introduced into the distilling retort and direct contact with bed, supplying heat to the latter for effecting the evolution of volatiles from the hydrocarbonaceous solid. The improvement consists of subjecting the volatile distillation products evolved and removed from the bed to a fractionation and separating selected relatively light and heavy hydrocarbon fractions from the distillation products, withdrawing at least one of the selected fractions from the prcess as a product heating at least one other of the selected fractions to high temperature by the indirect heat exchange with hot combustion gases, and introducing the thus heated hydrocarbon fraction into direct contact with the bed.

Reservoir evaluation of thin-bedded turbidites and hydrocarbon pore thickness estimation for an accurate quantification of resource

Science.gov (United States)

Omoniyi, Bayonle; Stow, Dorrik

2016-04-01

One of the major challenges in the assessment of and production from turbidite reservoirs is to take full account of thin and medium-bedded turbidites (succession, they can go unnoticed by conventional analysis and so negatively impact on reserve estimation, particularly in fields producing from prolific thick-bedded turbidite reservoirs. Field development plans often take little note of such thin beds, which are therefore bypassed by mainstream production. In fact, the trapped and bypassed fluids can be vital where maximising field value and optimising production are key business drivers. We have studied in detail, a succession of thin-bedded turbidites associated with thicker-bedded reservoir facies in the North Brae Field, UKCS, using a combination of conventional logs and cores to assess the significance of thin-bedded turbidites in computing hydrocarbon pore thickness (HPT). This quantity, being an indirect measure of thickness, is critical for an accurate estimation of original-oil-in-place (OOIP). By using a combination of conventional and unconventional logging analysis techniques, we obtain three different results for the reservoir intervals studied. These results include estimated net sand thickness, average sand thickness, and their distribution trend within a 3D structural grid. The net sand thickness varies from 205 to 380 ft, and HPT ranges from 21.53 to 39.90 ft. We observe that an integrated approach (neutron-density cross plots conditioned to cores) to HPT quantification reduces the associated uncertainties significantly, resulting in estimation of 96% of actual HPT. Further work will focus on assessing the 3D dynamic connectivity of the low-pay sands with the surrounding thick-bedded turbidite facies.

The modular pebble bed nuclear reactor - the preferred new sustainable energy source for electricity, hydrogen and potable water production?

International Nuclear Information System (INIS)

Kemeny, L.G.

2003-01-01

This paper describes a joint project of Massachusetts Institute of technology, Nu-Tec Inc. and Proto Power. The elegant simplicity of graphite moderated pebble bed reactor is the basis for the 'generation four' nuclear power plants. High Temperature Gas Cooled (HTGC) nuclear power plant have the potential to become the preferred base load sustainable energy source for the new millennium. The great attraction of these helium cooled 'Generation Four' nuclear plant can be summarised as follows: Factory assembly line production; Modularity and ease of delivery to site; High temperature Brayton Cycle ideally suited for cogeneration of electricity, potable water and hydrogen; Capital and operating costs competitive with hydrocarbon plant; Design is inherently meltdown proof and proliferation resistant

A liquid hydrocarbon deuteron source for neutron generators

Science.gov (United States)

Schwoebel, P. R.

2017-06-01

Experimental studies of a deuteron spark source for neutron generators using hydrogen isotope fusion reactions are reported. The ion source uses a spark discharge between electrodes coated with a deuterated hydrocarbon liquid, here Santovac 5, to inhibit permanent electrode erosion and extend the lifetime of high-output neutron generator spark ion sources. Thompson parabola mass spectra show that principally hydrogen and deuterium ions are extracted from the ion source. Hydrogen is the chief residual gas phase species produced due to source operation in a stainless-steel vacuum chamber. The prominent features of the optical emission spectra of the discharge are C+ lines, the hydrogen Balmer Hα-line, and the C2 Swan bands. Operation of the ion source was studied in a conventional laboratory neutron generator. The source delivered an average deuteron current of ˜0.5 A nominal to the target in a 5 μs duration pulse at 1 Hz with target voltages of -80 to -100 kV. The thickness of the hydrocarbon liquid in the spark gap and the consistency thereof from spark to spark influences the deuteron yield and plays a role in determining the beam-focusing characteristics through the applied voltage necessary to break down the spark gap. Higher breakdown voltages result in larger ion beam spots on the target and vice-versa. Because the liquid self-heals and thereby inhibits permanent electrode erosion, the liquid-based source provides long life, with 104 pulses to date, and without clear evidence that, in principle, the lifetime could not be much longer. Initial experiments suggest that an alternative cylindrical target-type generator design can extract approximately 10 times the deuteron current from the source. Preliminary data using the deuterated source liquid as a neutron-producing target are also presented.

Occurrence of polycyclic aromatic hydrocarbons in dust emitted from circulating fluidized bed boilers.

Science.gov (United States)

Kozielska, B; Konieczyńiski, J

2008-11-01

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in granulometric fractions of dust emitted from a hard coal fired circulating fluidized bed (CFB) boiler was investigated. The dust was sampled with the use of a Mark III impactor. In each fraction of dust, by using gas chromatography (GC), 16 selected PAHs and total PAHs were determined and the toxic equivalent B(a)P (TE B(a)P) was computed. The results, recalculated for the standard granulometric fractions, are presented as concentrations and content of the determined PAHs in dust. Distributions of PAHs and their profiles in the granulometric dust fractions were studied also. The PAHs in dust emitted from the CFB boiler were compared with those emitted from mechanical grate boilers; a distinctly lower content of PAHs was found in dust emitted from the former.

Hydrocarbons from algal bodies and vegetal sources - a prognosticated assessment

International Nuclear Information System (INIS)

Sen, Subhasis; Sen, Meera; Sen, Nandita.

1992-01-01

Hydrogen-rich vegetal matter and other similar plant derived sources are highlighted as a potential renewable source for hydrocarbon following a different route, i.e. low temperature carbonization of the processed material followed by hydrogenation of tar and subsequent processing and also fractionation of the products are discussed. (P.R.K.)

A study of light hydrocarbons (C{sub 4}-C{sub 1}3) in source rocks and petroleum fluid

Energy Technology Data Exchange (ETDEWEB)

Odden, Wenche

2000-07-01

This thesis consists of an introduction and five included papers. Of these, four papers are published in international journals and the fifth was submitted for review in April 2000. Emphasis has been placed on both naturally and artificially generated light hydrocarbons in petroleum fluids and their proposed source rocks as well as direct application of light hydrocarbons to oil/source rock correlations. Collectively, these papers describe a strategy for interpreting the source of the light hydrocarbons in original oils and condensates as well as the source of the asphaltene fractions from the reservoir fluids. The influence of maturity on light hydrocarbon composition has also been evaluated. The papers include (1) compositional data on the light hydrocarbons from thermal extracts and kerogen pyrolysates of sediment samples, (2) light hydrocarbon data of oils and condensates as well as the pyrolysis products of the asphaltenes from these fluids, (3) assessment of compositional alteration effects, such as selective losses of light hydrocarbons due to evaporation, thermal maturity, phase fractionation and biodegradation, (4) comparison of naturally and artificially generated light hydrocarbons, and (5) compound-specific carbon isotope analysis of the whole range of hydrocarbons of all sample types. (author)

Evaluation on occluded hydrocarbon in deep–ultra deep ancient source rocks and its cracked gas resources

Directory of Open Access Journals (Sweden)

Jian Li

2015-12-01

Full Text Available Oil-cracked gas, as the main type of high-over mature marine natural gas in China, is mainly derived from occluded hydrocarbon. So it is significant to carry out quantitative study on occluded hydrocarbon. In this paper, the occluded hydrocarbon volume of the main basins in China was calculated depending on their types, abundances and evolution stages by means of the forward method (experimental simulation and the inversion method (geologic profile dissection. And then, occluded hydrocarbon evolution models were established for five types of source rocks (sapropelic, sapropelic prone hybrid, humic prone hybrid, humic and coal. It is shown that the hydrocarbon expulsion efficiency of sapropelic and sapropelic prone hybrid excellent source rocks is lower than 30% at the low-maturity stage, 30%–60% at the principal oil generation stage, and 50%–80% at the high-maturity stage, which are all about 10% higher than that of humic prone hybrid and humic source rocks at the corresponding stages. The resource distribution and cracked gas expulsion of occluded hydrocarbon since the high-maturity stage of marine source rocks in the Sichuan Basin were preliminarily calculated on the basis of the evolution models. The cracked gas expulsion is 230.4 × 1012 m3 at the high evolution stage of occluded hydrocarbon of the Lower Cambrian Qiongzhusi Fm in this basin, and 12.3 × 1012 m3 from the source rocks of Sinian Doushantuo Fm, indicating good potential for natural gas resources. It is indicated that the favorable areas of occluded hydrocarbon cracked gas in the Qiongzhusi Fm source rocks in the Sichuan Basin include Gaoshiti–Moxi, Ziyang and Weiyuan, covering a favorable area of 4.3 × 104 km2.

Novel techniques for characterization of hydrocarbon emission sources in the Barnett Shale

Science.gov (United States)

Nathan, Brian Joseph

Changes in ambient atmospheric hydrocarbon concentrations can have both short-term and long-term effects on the atmosphere and on human health. Thus, accurate characterization of emissions sources is critically important. The recent boom in shale gas production has led to an increase in hydrocarbon emissions from associated processes, though the exact extent is uncertain. As an original quantification technique, a model airplane equipped with a specially-designed, open-path methane sensor was flown multiple times over a natural gas compressor station in the Barnett Shale in October 2013. A linear optimization was introduced to a standard Gaussian plume model in an effort to determine the most probable emission rate coming from the station. This is shown to be a suitable approach given an ideal source with a single, central plume. Separately, an analysis was performed to characterize the nonmethane hydrocarbons in the Barnett during the same period. Starting with ambient hourly concentration measurements of forty-six hydrocarbon species, Lagrangian air parcel trajectories were implemented in a meteorological model to extend the resolution of these measurements and achieve domain-fillings of the region for the period of interest. A self-organizing map (a type of unsupervised classification) was then utilized to reduce the dimensionality of the total multivariate set of grids into characteristic one-dimensional signatures. By also introducing a self-organizing map classification of the contemporary wind measurements, the spatial hydrocarbon characterizations are analyzed for periods with similar wind conditions. The accuracy of the classification is verified through assessment of observed spatial mixing ratio enhancements of key species, through site-comparisons with a related long-term study, and through a random forest analysis (an ensemble learning method of supervised classification) to determine the most important species for defining key classes. The hydrocarbon

Polycyclic aromatic hydrocarbons and organic matter associated to particulate matter emitted from atmospheric fluidized bed coal combustion

International Nuclear Information System (INIS)

Mastral, A.M.; Callen, M.S.; Garcia, T.

1999-01-01

The polycyclic aromatic hydrocarbons (PAH) and the organic matter (OM) content associated with particulate matter (PM) emissions from atmospheric fluidized bed coal combustion have been studied. The two main aims of the work have been (a) to study OM and PAH emissions as a function of the coal fluidized bed combustion (FBC) variables in solid phase and (b) to check if there is any correlation between OM and PAH contained in the PM. The combustion was carried out in a laboratory scale plant at different combustion conditions: temperature, percentage of oxygen excess, and total air flow. PAH associated on the particulate matter have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after PM extraction by sonication with dimethylformamide (DMF). It can be concluded that there is not a direct relationship between the OM content and the PAH supported in the PM emitted. In addition, neither PM or OM show dependence between themselves

Hydrogeochemistry and coal-associated bacterial populations from a methanogenic coal bed

Science.gov (United States)

Barnhart, Elliott P.; Weeks, Edwin P.; Jones, Elizabeth J.P.; Ritter, Daniel J.; McIntosh, Jennifer C.; Clark, Arthur C.; Ruppert, Leslie F.; Cunningham, Alfred B.; Vinson, David S.; Orem, William H.; Fields, Matthew W.

2016-01-01

Biogenic coalbed methane (CBM), a microbially-generated source of natural gas trapped within coal beds, is an important energy resource in many countries. Specific bacterial populations and enzymes involved in coal degradation, the potential rate-limiting step of CBM formation, are relatively unknown. The U.S. Geological Survey (USGS) has established a field site, (Birney test site), in an undeveloped area of the Powder River Basin (PRB), with four wells completed in the Flowers-Goodale coal bed, one in the overlying sandstone formation, and four in overlying and underlying coal beds (Knoblach, Nance, and Terret). The nine wells were positioned to characterize the hydraulic conductivity of the Flowers-Goodale coal bed and were selectively cored to investigate the hydrogeochemistry and microbiology associated with CBM production at the Birney test site. Aquifer-test results indicated the Flowers-Goodale coal bed, in a zone from about 112 to 120 m below land surface at the test site, had very low hydraulic conductivity (0.005 m/d) compared to other PRB coal beds examined. Consistent with microbial methanogenesis, groundwater in the coal bed and overlying sandstone contain dissolved methane (46 mg/L average) with low δ13C values (−67‰ average), high alkalinity values (22 meq/kg average), relatively positive δ13C-DIC values (4‰ average), and no detectable higher chain hydrocarbons, NO3−, or SO42−. Bioassay methane production was greatest at the upper interface of the Flowers-Goodale coal bed near the overlying sandstone. Pyrotag analysis identified Aeribacillus as a dominant in situbacterial community member in the coal near the sandstone and statistical analysis indicated Actinobacteria predominated coal core samples compared to claystone or sandstone cores. These bacteria, which previously have been correlated with hydrocarbon-containing environments such as oil reservoirs, have demonstrated the ability to produce biosurfactants to break down

A New Global Open Source Marine Hydrocarbon Emission Site Database

Science.gov (United States)

Onyia, E., Jr.; Wood, W. T.; Barnard, A.; Dada, T.; Qazzaz, M.; Lee, T. R.; Herrera, E.; Sager, W.

2017-12-01

Hydrocarbon emission sites (e.g. seeps) discharge large volumes of fluids and gases into the oceans that are not only important for biogeochemical budgets, but also support abundant chemosynthetic communities. Documenting the locations of modern emissions is a first step towards understanding and monitoring how they affect the global state of the seafloor and oceans. Currently, no global open source (i.e. non-proprietry) detailed maps of emissions sites are available. As a solution, we have created a database that is housed within an Excel spreadsheet and use the latest versions of Earthpoint and Google Earth for position coordinate conversions and data mapping, respectively. To date, approximately 1,000 data points have been collected from referenceable sources across the globe, and we are continualy expanding the dataset. Due to the variety of spatial extents encountered, to identify each site we used two different methods: 1) point (x, y, z) locations for individual sites and; 2) delineation of areas where sites are clustered. Certain well-known areas, such as the Gulf of Mexico and the Mediterranean Sea, have a greater abundance of information; whereas significantly less information is available in other regions due to the absence of emission sites, lack of data, or because the existing data is proprietary. Although the geographical extent of the data is currently restricted to regions where the most data is publicly available, as the database matures, we expect to have more complete coverage of the world's oceans. This database is an information resource that consolidates and organizes the existing literature on hydrocarbons released into the marine environment, thereby providing a comprehensive reference for future work. We expect that the availability of seafloor hydrocarbon emission maps will benefit scientific understanding of hydrocarbon rich areas as well as potentially aiding hydrocarbon exploration and environmental impact assessements.

Consideration of emergency source terms for pebble-bed high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Tao, Liu; Jun, Zhao; Jiejuan, Tong; Jianzhu, Cao

2009-01-01

Being the last barrier in the nuclear power plant defense-in-depth strategy, emergency planning (EP) is an integrated project. One of the key elements in this process is emergency source terms selection. Emergency Source terms for light water reactor (LWR) nuclear power plant (NPP) have been introduced in many technical documents, and advanced NPP emergency planning is attracting attention recently. Commercial practices of advanced NPP are undergoing in the world, pebble-bed high-temperature gas-cooled reactor (HTGR) power plant is under construction in China which is considered as a representative of advanced NPP. The paper tries to find some pieces of suggestion from our investigation. The discussion of advanced NPP EP will be summarized first, and then the characteristics of pebble-bed HTGR relating to EP will be described. Finally, PSA insights on emergency source terms selection and current pebble-bed HTGR emergency source terms suggestions are proposed

Oil spill aftermath : temporal evaluation of hydrocarbon sources in Guanabara Bay, Brazil

International Nuclear Information System (INIS)

Meniconi, M.F.G.; Massone, C.G.; Scofield, A.L.; Junior, V.J.F.

2005-01-01

The sources of polycyclic aromatic hydrocarbons (PAH) in environmental ecosystems are both natural and anthropogenic. PAHs interact with different types of environmental compartments and are subject to processes that lead to geochemical fates such as physical-chemical transformation, biodegradation and photo-oxidation. This study examined the sources of PAHs in the estuarine sediment of Guanabara Bay, Brazil following an accidental oil spill from an oil refinery in January 2000. The main portion of the oil was carried by tidal currents and wind. It spread over the water and reached islands and shorelines at the north part of the bay. The objective of this study was to determine the likely sources of hydrocarbons in the bay where untreated municipal sewage and industrial wastes are also dumped. Sediment samples were collected using cores and dredges from the intertidal and subtidal regions of the bay, reflecting both affected and unaffected areas. This paper summarized the results of 16 EPA priority PAH and their alkylated homologues from 21 sediment samples collected in the bay 10 days after the oil spill, immediately after the clean up effort, and then 3 years later. The hydrocarbon source was determined using PAH ratios for the samples studied. The highest PAH concentration was observed in 2000 as a result of the petrogenic and pyrolytic contribution to the sediments. 38 refs., 3 tabs., 9 figs

Hydrocarbon delineation in Muskeg : distinguishing biogenic from petrogenic sources

Energy Technology Data Exchange (ETDEWEB)

Harris, C. [UMA Engineering Ltd., Victoria, BC (Canada)

2006-07-01

The quantification of biogenic versus petrogenic hydrocarbons from an emulsion pipeline in a Muskeg setting in northeastern British Columbia was examined. This presentation provided an introduction and discussion of the challenges in Muskeg environments. It introduced the objectives of the study and the analytical approach. Some supporting literature involving studies on the distribution and origin of hydrocarbons in estuary sediments was also cited. Box plots of the physical and chemical characteristics of soil and chromatograms of gas chromatography flame ionization detector (GC-FID) and gas chromatography mass spectrometry (GC-MS) were presented. Last, the approach to establish a true biogenic source and the recommended analytical program and corrections for biogenic input were discussed. The definition of contaminated peat was introduced. tabs., figs.

Sources of polyaromatic hydrocarbons (PAH); Kildebestemmelse af polyaromatiske kulbrinter (PAH)

Energy Technology Data Exchange (ETDEWEB)

Egsgaard, H. [Forskningscenetr Risoe, Ald. for Plantebiologi og Biokemi (DK); Larsen, E. [Forskningscenter Risoe, Ald. for Optic og Fluid Dynamik (Denmark)

2000-03-01

Aromatic hydrocarbons including PAH compounds are thermally and chemically very stable compounds and are formed by gasification/pyrolysis of biomass. With reference to the tar compounds present in the produced gas from updraft gasifiers the sources responsible for the formation of naphthalene and poly-aromatic hydrocarbons have been investigated. The focus has been on thermal and oxidative conversions of compounds related to the lignin building blocks. Thus, phenols, 2-methoxy-phenols and 4-substituted-2-methoxy-phenols were investigated by introducing water solutions of the compounds into a continuos flow system operating in the temperature range 600-850 deg. C. The pyrolysis products were identified by GC/MS. The tar compounds reveal a well-defined and characteristic thermal transformation. Phenol is a strong source to naphthalene and indenes while 2-methoxyphenols are sources to aromatic oxo-compounds such as cinnamaldehyde. More complex systems are sources to higer PAH compounds. Thus, oligomers of phenol and 2-methoxyphenol give dibenzofuran and oligomers of isoeugenol are important sources to acenaphthylene. It is characteristic that the simple tar compounds investigated undergo loss of CO and hereby loss of the aromatic structure. The intermediary compounds are very reactive cyclo-pentadienes entering Diels-Alder reactions. The later products are transformed to aromatic compounds. The results may facilitate the determination of optimum conditions for updraft gasifiers and hence a reduction of PAH formation. (au)

MANTLE SOURCES OF GENERATION OF HYDROCARBONS: GEOLOGY-PHYSICAL SIGNS AND FORECAST-SEARCHING CRITERIONS OF MAPPING; REGULARITY OF AN OIL-AND-GAS-BEARING CAPACITY AS UNLOADING REFLEX OF MANTLE HYDROCARBON-SYSTEMS IN THE CRUST OF THE EARTH

OpenAIRE

Тімурзіїв, А.І.

2017-01-01

In the conditions of the developed uncertainty concerning the nature of primary sources (donors) and the generation focal (reactionary chambers) of deep hydrocarbons, questions of the nature of donors and the sources of generation of deep hydrocarbons systems, the mechanism and ways of generation and in-source mobilization of hydrocarbons in the top mantle of the Earth and evacuation (vertical migration) of hydrocarbon-systems from the generation sources in the mantle of the Earth into the ac...

Occurrence and sources of aliphatic hydrocarbons in surface soils from Riyadh city, Saudi Arabia

Directory of Open Access Journals (Sweden)

Ahmed I. Rushdi

2013-01-01

Full Text Available Soil particles contain a variety of anthropogenic and natural organic components derived from many sources such as industrial and traffic fossil fuel emissions and terrestrial biota. The organic contents of soil and sand from the Arabian region have not fully characterized. Thus, samples of fine soil particles (sieved to <125 μM were collected from the Riyadh area in November 2006 (late summer and February 2007 (late winter. The samples were extracted with a mixture of dichloromethane/hexane and analyzed by gas chromatography–mass spectroscopy (GCMS in order to characterize the chemical composition and sources of aliphatic hydrocarbons. The results showed that both anthropogenic and natural biogenic inputs were the major sources of the aliphatic hydrocarbons in these extracts. Vehicular emission products and discarded plastics were the major anthropogenic sources in the fine particles of the soils and ranged from 64% to 96% in November 2006 and from 70% to 92% in February 2007. Their tracers were n-alkanes, hopanes, sterane, plasticizers and UCM. Vegetation was also a major natural source of hydrocarbon compounds in samples ranging from ∼0% to18% in November 2006 and from 1% to 13% in February 2007 and included n-alkanes and triterpenoids.

Anoxic environments and oil source bed genesis

Energy Technology Data Exchange (ETDEWEB)

Demaison, G J [Chevron Overseas Petroleum Inc., San Francisco, CA; Moore, G T

1980-01-01

The anoxic, aquatic, environment is a mass of water so depleted in oxygen that virtually all aerobic biological activity has ceased. Anoxic conditions occur where the demand for oxygen in the water column exceeds the supply. The specific cause for preferential lipid enrichment probably relates to the biochemistry of anaerobic bacterial activity. Recent evidence suggests that ancient organic-rich sediments containing hydrogen-rich kerogens (potential oil source beds) were deposited in similar anoxic environments. We propose the following classification for modern aquatic anoxic settings: (1) Large anoxic lakes - Permanent stratification promotes development of anoxic bottom water, particularly in large, deep lakes, which are not subject to seasonal overturn, e.g., Lake Tanganyika. (2) Anoxic silled basins - Landlocked silled basins with positive water balance tend to become anoxic. Typical are the Baltic and Black Seas. In arid region seas (Red and Mediterranean Seas), evaporation exceeds river inflow, causing negative water balance and well-aerated, nutrient-depleted bottom waters. (3) Anoxic layers caused by upwelling - Develop only when the oxygen supply in deep water cannot match demand by decaying organisms. Examples are the Benguela current and Peru coastal upwelling. (4) Open ocean anoxic layers - Found at intermediate depths in the northeastern Pacific and northern Indian Oceans; due to distance from deep, oxygenated polar water sources. Analogous to world-wide anoxic events at times of global climatic warm-ups and major transgressions, as in late Jurassic and middle Cretaceous time. Petroleum exploration can be greatly assisted by using geochemistry to identify paleo-anoxic events in the stratigraphic record. Recognition of the proposed anoxic models in ancient sedimentary basins should help in regional mapping of oil shales and oil-source beds. 17 figures.

A holistic approach to hydrocarbon source allocation in the subtidal sediments of Prince William Sound, Alaska, embayments

International Nuclear Information System (INIS)

Page, D.S.; Bence, A.E.; Burns, W.A.; Boehm, P.D.; Brown, J.S.; Douglas, G.S.

2002-01-01

The complex organic geochemistry record in the subtidal sediments of Prince William Sound, Alaska is a result of much industrial and human activity in the region. Recent oil spills and a regional background of natural petroleum hydrocarbons originating from active hydrocarbon systems in the northern Gulf of Alaska also contribute to the geochemical record. Pyrogenic and petrogenic polycyclic aromatic hydrocarbons (PAH) are introduced regularly to the subtidal sediments at sites of past and present human activities including villages, fish hatcheries, fish camps and recreational campsites as well as abandoned settlements, canneries, sawmills and mines. Hydrocarbon contributions are fingerprinted and quantified using a holistic approach where contributions from multiple sources is determined. The approach involves a good understanding of the history of the area to identify potential sources. It also involves extensive collection of representative samples and an accurate quantitative analysis of the source and sediment samples for PAH analytes and chemical biomarker compounds. Total organic carbon (TOC) does not work in restricted embayments because of a constrained least-square algorithm to determine hydrocarbon sources. It has been shown that sources contributing to the natural petrogenic background are present in Prince William Sound. In particular, pyrogenic hydrocarbons such as combustion products of diesel is significant where there was much human activity. In addition, petroleum produced from the Monterey Formation in California is present in Prince William Sound because in the past, oil and asphalt shipped from California was widely used for fuel. Low level residues of weathered Alaskan North Slope crude oil from the Exxon Valdez spill are also still present. 30 refs., 4 tabs., 2 figs

Recovery of hydrocarbon oils

Energy Technology Data Exchange (ETDEWEB)

1941-02-10

A process is disclosed for recovery of hydrocarbon oils, especially lubricating oils or diesel oils, through pressure hydrogenation of distillation, extraction of hydrogenation products from coal or coaly materials or from oils such as mineral oils or tars in liquid phase by use in a reaction vessel of fixed-bed catalysts, characterized in that as starting material is employed material which has been freed of asphaltic and resinous material by hydrogenation refining, vacuum-steam distillation, treatment with hydrogen-rich hydrocarbons (hydroforming), or sulfuric acid.

Effects of setting new source performance standards for fluidized-bed combustion systems

Energy Technology Data Exchange (ETDEWEB)

1978-02-01

This study was undertaken for the US Environmental Protection Agency to examine the potential consequences of revisions in New Source Performance Standards (NSPS) on fluidized-bed combustor-based steam electric generators of greater than 250,000,000 Btu. A study of the appropriateness and differential effects of alternate regulatory approaches to the standards-setting process was made. Problems dealing with an emerging technology such as fluidized-bed combustion were emphasized. Finally, an examination was made of the potential benefits of fluidized-bed combustion (FBC) systems relative to conventional coal-fired systems equipped with scrubbers. Information is included on the relative advantages and disadvantages of utility-sized fluidized-bed combustors, the technical consequences of NSPS alternatives, policy implications concerning NSPS for steam-electric generators, and cost models for atmospheric and pressurized FBC systems. (LCL)

Hydrocarbon Source Signatures in Houston, Texas: Influence of the Petrochemical Industry

Energy Technology Data Exchange (ETDEWEB)

Jobson, B Tom T; Berkowitz, Carl M; Kuster, W C; Goldan, P D; Williams, E J; Fesenfeld, F; Apel, Eric; Karl, Thomas G; Lonneman, William A; Riemer, D

2004-12-22

Observations of C1-C10 hydrocarbon mixing ratios measured by in-situ instrumentation at the La Porte super site during the TexAQS 2000 field experiment are reported. The La Porte data were compared to a roadway vehicle exhaust signature obtained from canister samples collected in the Houston Washburn tunnel during the same summer to better understand the impact of petrochemical emissions of hydrocarbons at the site. It is shown that the abundance of ethene, propene, 1-butene, C2-C4 alkanes, hexane, cyclohexane, methylcyclohexane, isopropylbenzene, and styrene at La Porte were systematically impacted by petrochemical industry emissions. Coherent power law relationships between frequency distribution widths of hydrocarbon mixing ratios and their local lifetimes clearly identify two major source groups, roadway vehicle emissions and industrial emissions. Distributions of most aromatics and long chain alkanes were consistent with roadway vehicle emissions as the dominant source. Airmass reactivity was generally dominated by C1-C3 aldehydes. Propene and ethene sometimes dominated air mass reactivity with HO loss frequencies often greater than 10 s-1. Ozone mixing ratios near 200 ppbv were observed on two separate occasions and these air masses appear to have been impacted by industrial emissions of alkenes from the Houston Ship Channel. The La Porte data provide evidence of the importance of industrial emissions of ethene and propene on air masses reactivity and ozone formation in Houston.

Low-maturity Kulthieth Formation coal : a possible source of polycyclic aromatic hydrocarbons in benthic sediment of the Northern Gulf of Alaska

International Nuclear Information System (INIS)

Van Kooten, G.K.; Short, J.W.; Kolak, J.J.

2002-01-01

This study addressed the issue of sources of hydrocarbons for benthic sediments in the Gulf of Alaska (GOA) with particular reference to the application of forensic geology to identify end members and to explain the geologic setting and processes affecting the system. Native coals and natural seep oils have been questioned in the past decade as possible sources of background hydrocarbons because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Native coal has also been dismissed as a pollution source because ratios of labile hydrocarbons to total organic carbon for Bering River coal field (BRCF) sources are too low to be consistent with GOA sediments. The authors present evidence that perhaps native coal has been prematurely dismissed as a pollution source because BRCF coals do not represent adequately the geochemical signatures of coals elsewhere in the Kulthieth Formation which have much higher PAH:TOC ratios. The patterns of labile hydrocarbons in these low thermal maturity coals indicate a genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analysis of the coal suggests it is a significant source of PAH, and it was cautioned that source models that do not include this source will underestimate the contribution of native coals to the background hydrocarbon signature in the Gulf of Alaska. 32 refs., 2 tabs., 8 figs

Direct photolysis of polycyclic aromatic hydrocarbons in drinking water sources

International Nuclear Information System (INIS)

Sanches, S.; Leitao, C.; Penetra, A.; Cardoso, V.V.; Ferreira, E.; Benoliel, M.J.; Crespo, M.T. Barreto; Pereira, V.J.

2011-01-01

Highlights: → Low pressure UV photolysis can be used by drinking water utilities to degrade PAHs. → Real water matrices with different compositions were tested. → Photolysis kinetic parameters and by-product formation are described. → The formation of photolysis by-products is highly dependent on the source waters. - Abstract: The widely used low pressure lamps were tested in terms of their efficiency to degrade polycyclic aromatic hydrocarbons listed as priority pollutants by the European Water Framework Directive and the U.S. Environmental Protection Agency, in water matrices with very different compositions (laboratory grade water, groundwater, and surface water). Using a UV fluence of 1500 mJ/cm 2 , anthracene and benzo(a)pyrene were efficiently degraded, with much higher percent removals obtained when present in groundwater (83-93%) compared to surface water (36-48%). The removal percentages obtained for fluoranthene were lower and ranged from 13 to 54% in the different water matrices tested. Several parameters that influence the direct photolysis of polycyclic aromatic hydrocarbons were determined and their photolysis by-products were identified by mass spectrometry. The formation of photolysis by-products was found to be highly dependent on the source waters tested.

First post-fire flush in a Mediterranean temporary stream: source ascription in bed sediments

Science.gov (United States)

Estrany Bertos, Joan; García-Comendador, Julián; Fortesa, Josep; Calsamiglia, Aleix; Garcias, Francesca

2017-04-01

First flushes can be of great importance for suspended-sediment transport in fluvial systems of drylands, being temporary streams a characteristic feature of Mediterranean basins. After a wildfire, storm flows may enhance runoff delivery to channels and then increasing the first-flush effect. 137Cs and 210Pbex were used as tracers for recognizing the first post-fire flush effect in the source ascription of bed sediments temporarily stored in a Mediterranean temporary stream severely affected by a wildfire. Thirty potential sediment source samples were collected along the main stem of a catchment located in Mallorca (Spain) during a field campaign developed some weeks after the wildfire. The sample collection was designed considering the wildfire affection, and also distinguishing between soil surface and channel bank. To quantify the relative source contribution to the bed sediment temporarily stored, five sediment samples -deposited during the first storm occurred three months after the wildfire- were collected into the bed stream of the main channel. The 137Cs and 210Pbex concentrations were measured by gamma spectrometry. Then, a linear mixing model was used to establish the relative contribution of each source type to the bed sediments discerning between the most upstream and the downstream parts of the catchment. Post-fire first-flush effect was generated by a torrential event with a suspended-sediment concentration peak ca. 33,618 mg L-1, although transmission losses under a very low runoff coefficient (1%) promoted sediment deposition. Significant differences were observed in fallout radionuclide concentrations between burned surface soil and channel bank samples (p 0.05). Source ascription in bed sediments in the middle stream shows that 67% was generated in burned hillslopes, reaching 75% in the downstream part because downstream propagation of the sediment derived from the burned area. Bed sediments were mostly generated in burned hillslopes because of

Investigations on the pyrolysis of hydrocarbons in the inductive coupled RF-plasma and the deposited pyrocarbon

International Nuclear Information System (INIS)

Eisgruber, H.; Mazurkiewicz, M.; Nickel, H.

1979-08-01

The pyrocarbon coatings of the nuclear fuel particles for the High-Temperature Reactor (HTR) are produced by pyrolysis of hydrocarbons under high temperatures. The investigations of the inductive coupled argon or argon/hydrocarbon-plasma performed in the frame of this work deliver a contribution for the clarification of pyrolysis processes and the production of pyrolytic carbons in the plasma of an electric discharge. The argon-plasma, as high-temperature source, is diagnosed theoretically and emission-spectroscopically. To the pure argon-plasma the various hydrocarbons are added. Due to the thermal decomposition the carbon is separated in solid form. The structure of the deposited pyrocarbon is composed of different components. The depositions are characterised with the principles in use at the IRW and are assigned to the fluidized bed pyrocarbons as fas as possible. (orig.) [de

Low-maturity Kulthieth Formation coal: A possible source of polycyclic aromatic hydrocarbons in benthic sediment of the northern Gulf of Alaska

Science.gov (United States)

Van Kooten, G. K.; Short, J.W.; Kolak, J.J.

2002-01-01

The successful application of forensic geology to contamination studies involving natural systems requires identification of appropriate endmembers and an understanding of the geologic setting and processes affecting the systems. Studies attempting to delineate the background, or natural, source for hydrocarbon contamination in Gulf of Alaska (GOA) benthic sediments have invoked a number of potential sources, including seep oils, source rocks, and coal. Oil seeps have subsequently been questioned as significant sources of hydrocarbons present in benthic sediments of the GOA in part because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Likewise, native coal has been dismissed in part because ratios of labile hydrocarbons to total organic carbon (e.g. PAH:TOC) for Bering River coal field (BRCF) sources are too low - i.e. the coals are over mature - to be consistent with GOA sediments. We present evidence here that native coal may have been prematurely dismissed, because BRCF coals do not adequately represent the geochemical signatures of coals elsewhere in the Kulthieth Formation. Contrary to previous thought, Kulthieth Formation coals east of the BRCF have much higher PAH: TOC ratios, and the patterns of labile hydrocarbons in these low thermal maturity coals suggest a possible genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analyses of low-maturity Kulthieth Formation coal indicate the low maturity coal is a significant source of PAH. Source apportionment models that neglect this source will underestimate the contribution of native coals to the regional background hydrocarbon signature. ?? Published by Elsevier Science Ltd. on behalf of AEHS.

Pilot fluidized bed combustor system applied to thermal energy production from light hydrocarbons - part I: description and hydrodynamics analysis; Sistema combustor piloto a leito fluidizado para producao de energia termica a partir de hidrocarbonetos leves. Parte I: descricao e analise hidrodinamica do sistema

Energy Technology Data Exchange (ETDEWEB)

Araujo, Leandro P. de; Souza Junior, Francisco de Assis; Alves, Stella M.A.; Estevao, Paulo [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lucena, Sergio; Souza, Phillipi R. de O. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Lab. de Controle e Otimizacao de Processos; Santos, Douglas A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

2008-07-01

During the last years, the employment of light hydrocarbons in combustion systems for power generation has been announced by Brazilian Government's like a great bet for diversification the energetic matrix in spite of the provisional crisis. As consequence, high demand and growing R and D investments caused immediate reflexes in all economical and industrial sectors of the Natural Gas chain, mainly considering the gas from Campos, Santos and Espirito Santo offshore fields offered to the market. Regarding this, Northeast Region of Brazil shows itself to be attentive to the energy market tendencies and to environmental sector, creating conditions for developing new technologies and applications for the gas consumption. Among the possible applications of the gas consumption, the fluidized bed combustion systems are highlighted, like a real alternative for energy applying of the hydrocarbons produced, considering a good safety range to effective environmental demands. Thereby, the present work aimed to perform the description of a pilot fluidized bed combustor system with sand using light hydrocarbons - specifically, natural gas and LPG. Thereby, said pilot fluidized bed combustor operates isothermically without developing flames and/or hot spots. Besides the exposed, a hydrodynamic analysis of the system was made, identifying variables and parameters onto fluidized bed combustion process. (author.

Characterization of Biosurfactant Produced during Degradation of Hydrocarbons Using Crude Oil As Sole Source of Carbon.

Science.gov (United States)

Patowary, Kaustuvmani; Patowary, Rupshikha; Kalita, Mohan C; Deka, Suresh

2017-01-01

Production and spillage of petroleum hydrocarbons which is the most versatile energy resource causes disastrous environmental pollution. Elevated oil degrading performance from microorganisms is demanded for successful microbial remediation of those toxic pollutants. The employment of biosurfactant-producing and hydrocarbon-utilizing microbes enhances the effectiveness of bioremediation as biosurfactant plays a key role by making hydrocarbons bio-available for degradation. The present study aimed the isolation of a potent biosurfactant producing indigenous bacteria which can be employed for crude oil remediation, along with the characterization of the biosurfactant produced during crude oil biodegradation. A potent bacterial strain Pseudomonas aeruginosa PG1 (identified by 16s rDNA sequencing) was isolated from hydrocarbon contaminated soil that could efficiently produce biosurfactant by utilizing crude oil components as the carbon source, thereby leading to the enhanced degradation of the petroleum hydrocarbons. Strain PG1 could degrade 81.8% of total petroleum hydrocarbons (TPH) after 5 weeks of culture when grown in mineral salt media (MSM) supplemented with 2% (v/v) crude oil as the sole carbon source. GCMS analysis of the treated crude oil samples revealed that P. aeruginosa PG1 could potentially degrade various hydrocarbon contents including various PAHs present in the crude oil. Biosurfactant produced by strain PG1 in the course of crude oil degradation, promotes the reduction of surface tension (ST) of the culture medium from 51.8 to 29.6 mN m -1 , with the critical micelle concentration (CMC) of 56 mg L -1 . FTIR, LC-MS, and SEM-EDS studies revealed that the biosurfactant is a rhamnolipid comprising of both mono and di rhamnolipid congeners. The biosurfactant did not exhibit any cytotoxic effect to mouse L292 fibroblastic cell line, however, strong antibiotic activity against some pathogenic bacteria and fungus was observed.

Characterization of Biosurfactant Produced during Degradation of Hydrocarbons Using Crude Oil As Sole Source of Carbon

Science.gov (United States)

Patowary, Kaustuvmani; Patowary, Rupshikha; Kalita, Mohan C.; Deka, Suresh

2017-01-01

Production and spillage of petroleum hydrocarbons which is the most versatile energy resource causes disastrous environmental pollution. Elevated oil degrading performance from microorganisms is demanded for successful microbial remediation of those toxic pollutants. The employment of biosurfactant-producing and hydrocarbon-utilizing microbes enhances the effectiveness of bioremediation as biosurfactant plays a key role by making hydrocarbons bio-available for degradation. The present study aimed the isolation of a potent biosurfactant producing indigenous bacteria which can be employed for crude oil remediation, along with the characterization of the biosurfactant produced during crude oil biodegradation. A potent bacterial strain Pseudomonas aeruginosa PG1 (identified by 16s rDNA sequencing) was isolated from hydrocarbon contaminated soil that could efficiently produce biosurfactant by utilizing crude oil components as the carbon source, thereby leading to the enhanced degradation of the petroleum hydrocarbons. Strain PG1 could degrade 81.8% of total petroleum hydrocarbons (TPH) after 5 weeks of culture when grown in mineral salt media (MSM) supplemented with 2% (v/v) crude oil as the sole carbon source. GCMS analysis of the treated crude oil samples revealed that P. aeruginosa PG1 could potentially degrade various hydrocarbon contents including various PAHs present in the crude oil. Biosurfactant produced by strain PG1 in the course of crude oil degradation, promotes the reduction of surface tension (ST) of the culture medium from 51.8 to 29.6 mN m−1, with the critical micelle concentration (CMC) of 56 mg L−1. FTIR, LC-MS, and SEM-EDS studies revealed that the biosurfactant is a rhamnolipid comprising of both mono and di rhamnolipid congeners. The biosurfactant did not exhibit any cytotoxic effect to mouse L292 fibroblastic cell line, however, strong antibiotic activity against some pathogenic bacteria and fungus was observed. PMID:28275373

Source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments from Khuzestan province, Iran

DEFF Research Database (Denmark)

Lübeck, Josephine; Poulsen, Kristoffer Gulmark; Knudsen, Sofie B.

2016-01-01

of polycyclic aromatic hydrocarbon (PAH) pollution. A four-component principal component analysis (PCA) model was obtained. While principal component 1 (PC1) was related to the total concentration of PAHs, the remaining PCs described three distinct sources: PC2 and PC3 collectively differentiate between...

Bubbling bed catalytic hydropyrolysis process utilizing larger catalyst particles and smaller biomass particles featuring an anti-slugging reactor

Science.gov (United States)

Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

2014-09-23

This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

Bubbling bed catalytic hydropyrolysis process utilizinig larger catalyst particles and small biomass particles featuring an anti-slugging reactor

Science.gov (United States)

Marker, Terry L.; Felix, Larry G.; Linck, Martin B.; Roberts, Michael J.

2016-12-06

This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

Characterization, Distribution, Sources and Origins of Aliphatic Hydrocarbons from Surface Sediment of Prai Strait, Penang, Malaysia: A Widespread Anthropogenic Input

Directory of Open Access Journals (Sweden)

Mahyar Sakari

2008-07-01

Full Text Available Persistent organic pollutants such as petroleum hydrocarbons are one of the most serious and important class of pollutants that face to many countries including Malaysia. Aliphatic hydrocarbons contain straight chain alkane; derive from anthropogenic and natural sources to the marine environment. The multi-purpose strait of Prai is located in the Northwest of Peninsular Malaysia plays an important economic role in the Southeast Asia. Twenty surface sediment samples were collected using Eckman dredge to measure the concentration and determine the characterization, sources and origins of the aliphatic hydrocarbons in December 2006. Samples (top 4 cm were extracted with Soxhlet, treated with activated copper and subjected to 2 steps column chromatography for purification and fractionation. Alkane fraction injected into Gas Chromatography–Flame Ionization Detector (GC-FID for instrumental analysis. The results showed that total n-alkane concentrations are ranging from 512 to 10770 ng/mg d. w. Carbon Preferences Index (CPI revealed an extreme widespread anthropogenic input and naturally derived (CPI= 0 to 4.88 hydrocarbons in the study area. The ratio of C31/C19 indicated that natural hydrocarbons are generating from terrestrial vascular plants and transferring by rivers. The characteristics of Major Hydrocarbons provided evidences that oil and its derivatives either fresh or degraded are the major contributors of the pollution in the study area. Statistical approaches also confirmed that 85% of study area affected by oil sources of pollution. It is seen that aliphatic hydrocarbons mostly transfer by lateral input to the marine environment than atmospheric movements.

The use of polynuclear aromatic hydrocarbon (PAH) alkyl homologues in determining petroleum source identification and weathering

International Nuclear Information System (INIS)

Brown, J.S.; Boehm, P.D.; Sauer, T.C.; Wong, W.M.C.

1993-01-01

Techniques utilizing double ratio plots of selected polynuclear aromatic hydrocarbon (PAH) alkyl homologues were used to identify and distinguish crude oils and refined petroleum products from each other and to distinguish petroleum sources in complex pollutant regimes. Petroleum samples were fractionated by high performance liquid chromatography (HPLC) into saturated and aromatic (PAH) hydrocarbon fractions. The saturated hydrocarbon fractions were then analyzed by gas chromatography/flame ionization detection (GC/FID) to obtain a resolved/unresolved alkane fingerprint of each oil. The aromatic fractions of the oils were analyzed by gas chromatography/mass spectrometry (GC/MS) for PAH and selected alkyl homologues. Comparisons of the saturated hydrocarbon fingerprints indicated that some oils were indistinguishable based on the alkane fingerprint alone. Another double ratio plot of the alkyl chrysenes and alkyl dibenzothiophenes was effective in establishing the weathering of oil in environmental samples which were processed using the same analytical techniques, since the dibenzothiophenes are degraded more rapidly than the chrysenes. The application of selected ratios in oil spill source identification in complex environmental samples from Suisin Bay California and Boston Harbor are discussed. The use of ratios to measure the extent of weathering in oil spill samples from Prince William Sound and the Gulf of Alaska is examined

Chemical fingerprinting of hydrocarbon-contamination in soil

DEFF Research Database (Denmark)

Boll, Esther Sørensen; Nejrup, Jens; Jensen, Julie K.

2015-01-01

Chemical fingerprinting analyses of 29 hydrocarbon-contaminated soils were performed to assess the soil quality and determine the main contaminant sources. The results were compared to an assessment based on concentrations of the 16 priority polycyclic aromatic hydrocarbons pointed out by the U...... and in assessing weathering trends of hydrocarbon contamination in the soils. Multivariate data analysis of sum-normalized concentrations could as a stand-alone tool distinguish between hydrocarbon sources of petrogenic and pyrogenic origin, differentiate within petrogenic sources, and detect weathering trends....... Diagnostic ratios of PACs were not successful for source identification of the heavily weathered hydrocarbon sources in the soils. The fingerprinting of contaminated soils revealed an underestimation of PACs in petrogenic contaminated soils when the assessment was based solely on EPAPAH16. As alkyl...

Plasma devices for hydrocarbon reformation

KAUST Repository

Cha, Min

2017-01-01

Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured

Hydrocarbon migration and accumulation in the Upper Cretaceous Qingshankou Formation, Changling Sag, southern Songliao Basin: Insights from integrated analyses of fluid inclusion, oil source correlation and basin modelling

Science.gov (United States)

Dong, Tian; He, Sheng; Wang, Dexi; Hou, Yuguang

2014-08-01

The Upper Cretaceous Qingshankou Formation acts as both the source and reservoir sequence in the Changling Sag, situated in the southern end of the Songliao Basin, northeast China. An integrated approach involving determination of hydrocarbon charging history, oil source correlation and hydrocarbon generation dynamic modeling was used to investigate hydrocarbon migration processes and further predict the favorable targets of hydrocarbon accumulations in the Qingshankou Formation. The hydrocarbon generation and charge history was investigated using fluid inclusion analysis, in combination with stratigraphic burial and thermal modeling. The source rocks began to generate hydrocarbons at around 82 Ma and the hydrocarbon charge event occurred from approximately 78 Ma to the end of Cretaceous (65.5 Ma) when a large tectonic uplift took place. Correlation of stable carbon isotopes of oils and extracts of source rocks indicates that oil was generated mainly from the first member of Qingshankou Formation (K2qn1), suggesting that hydrocarbon may have migrated vertically. Three dimensional (3D) petroleum system modeling was used to evaluate the processes of secondary hydrocarbon migration in the Qingshankou Formation since the latest Cretaceous. During the Late Cretaceous, hydrocarbon, mainly originated from the Qianan depression, migrated laterally to adjacent structural highs. Subsequent tectonic inversion, defined as the late Yanshan Orogeny, significantly changed hydrocarbon migration patterns, probably causing redistribution of primary hydrocarbon reservoirs. In the Tertiary, the Heidimiao depression was buried much deeper than the Qianan depression and became the main source kitchen. Hydrocarbon migration was primarily controlled by fluid potential and generally migrated from relatively high potential areas to low potential areas. Structural highs and lithologic transitions are potential traps for current oil and gas exploration. Finally, several preferred hydrocarbon

Environmental forensic principals for sources allocation of polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

O'Sullivan, G.; Martin, E.; Sandau, C.D.

2008-01-01

Polycyclic aromatic hydrocarbons (PAH) are organic compounds which include only carbon and hydrogen with a fused ring structure containing at least two six-sided benzene rings but may also contain additional fused rings that are not six-sided. The environmental forensic principals for sources allocation of PAHs were examined in this presentation. Specifically, the presentation addressed the structure and physiochemical properties of PAHs; sources and sinks; fate and behaviour; analytical techniques; conventional source identification techniques; and toxic equivalent fingerprinting. It presented a case study where residents had been allegedly exposed to dioxins, PAHs and metals released from a railroad tie treatment plant. The classification of PAHs is governed by thermodynamic properties such as biogenic, petrogenic, and pyrogenic properties. A number of techniques were completed, including chemical fingerprinting; molecular diagnostic ratios; cluster analysis; principal component analysis; and TEF fingerprinting. These techniques have shown that suspected impacted sites do not all share similar PAH signatures indicating the potential for various sources. Several sites shared similar signatures to background locations. tabs., figs

A chemical and thermodynamic model of oil generation in hydrocarbon source rocks

Science.gov (United States)

Helgeson, Harold C.; Richard, Laurent; McKenzie, William F.; Norton, Denis L.; Schmitt, Alexandra

2009-02-01

Thermodynamic calculations and Gibbs free energy minimization computer experiments strongly support the hypothesis that kerogen maturation and oil generation are inevitable consequences of oxidation/reduction disproportionation reactions caused by prograde metamorphism of hydrocarbon source rocks with increasing depth of burial.These experiments indicate that oxygen and hydrogen are conserved in the process.Accordingly, if water is stable and present in the source rock at temperatures ≳25 but ≲100 °C along a typical US Gulf Coast geotherm, immature (reduced) kerogen with a given atomic hydrogen to carbon ratio (H/C) melts incongruently with increasing temperature and depth of burial to produce a metastable equilibrium phase assemblage consisting of naphthenic/biomarker-rich crude oil, a type-II/III kerogen with an atomic hydrogen/carbon ratio (H/C) of ˜1, and water. Hence, this incongruent melting process promotes diagenetic reaction of detritus in the source rock to form authigenic mineral assemblages.However, in the water-absent region of the system CHO (which is extensive), any water initially present or subsequently entering the source rock is consumed by reaction with the most mature kerogen with the lowest H/C it encounters to form CO 2 gas and a new kerogen with higher H/C and O/C, both of which are in metastable equilibrium with one another.This hydrolytic disproportionation process progressively increases both the concentration of the solute in the aqueous phase, and the oil generation potential of the source rock; i.e., the new kerogen can then produce more crude oil.Petroleum is generated with increasing temperature and depth of burial of hydrocarbon source rocks in which water is not stable in the system CHO by a series of irreversible disproportionation reactions in which kerogens with higher (H/C)s melt incongruently to produce metastable equilibrium assemblages consisting of crude oil, CO 2 gas, and a more mature (oxidized) kerogen with a lower

The potentiality of hydrocarbon generation of the Jurassic source rocks in Salam-3x well,

Directory of Open Access Journals (Sweden)

Mohamed M. El Nady

2016-03-01

Full Text Available The present work deals with the identification of the potential and generating capability of oil generation in the Jurassic source rocks in the Salam-3x well. This depending on the organo-geochemical analyses of cutting samples representative of Masajid, Khatatba and Ras Qattara formations, as well as, representative extract samples of the Khatatba and Ras Qattara formations. The geochemical analysis suggested the potential source intervals within the encountered rock units as follows: Masajid Formation bears mature source rocks and have poor to fair generating capability for generating gas (type III kerogen. Khatatba Formation bears mature source rock, and has poor to good generating capability for both oil and gas. Ras Qattara Formation constituting mature source rock has good to very good generating capability for both oil and gas. The burial history modeling shows that the Masajid Formation lies within oil and gas windows; Khatatba and Ras Qattara formations lie within the gas window. From the biomarker characteristics of source rocks it appears that the extract is genetically related as the majority of them were derived from marine organic matters sources (mainly algae deposited under reducing environment and take the direction of increasing maturity and far away from the direction of biodegradation. Therefore, Masajid Formation is considered as effective source rocks for generating hydrocarbons, while Khatatba and Ras Qattara formations are the main source rocks for hydrocarbon accumulations in the Salam-3x well.

Using hydrocarbon as a carbon source for synthesis of carbon nanotube by electric field induced needle-pulsed plasma

International Nuclear Information System (INIS)

Kazemi Kia, Kaveh; Bonabi, Fahimeh

2013-01-01

In this work different hydrocarbons are used as the carbon source, in the production of carbon nanotubes (CNTs) and nano onions. An electric field induced needle pulse arc-discharge reactor is used. The influence of starting carbon on the synthesis of CNTs is investigated. The production efficiency is compared for Acetone, Isopropanol and Naphthalene as simple hydrocarbons. The hydrocarbons are preheated and then pretreated by electric field before being exposed to plasma. The hydrocarbon vapor is injected into plasma through a graphite spout in the cathode assembly. The pulsed plasma takes place between two graphite rods while a strong electric field has been already established alongside the electrodes. The pulse width is 0.3 μs. Mechanism of precursor decomposition is discussed by describing three forms of energy that are utilized to disintegrate the precursor molecules: thermal energy, electric field and kinetic energy of plasma. Molecular polarity of a hydrocarbon is one of the reasons for choosing carbon raw material as a precursor in an electric field induced low power pulsed-plasma. The results show that in order to obtain high quality carbon nanotubes, Acetone is preferred to Isopropanol and Naphthalene. Scanning probe microscopy techniques are used to investigate the products. - Highlights: • We synthesized CNTs (carbon nano tubes) by needle pulsed plasma. • We use different hydrocarbons as carbon source in the production of CNTs. • We investigated the influence of starting carbon on the synthesis of CNTs. • Thermal energy, electric field and kinetic energy are used to break carbon bonds. • Polar hydrocarbon molecules are more efficient than nonpolar ones in production

A review of atmospheric polycyclic aromatic hydrocarbons: sources, fate and behavior

International Nuclear Information System (INIS)

Baek, S.O.; Field, R.A.; Goldstone, M.E.; Kirk, P.W.; Lester, J.N.; Perry, R.

1991-01-01

A review has been written to assess the sources, fate and behavior of polycyclic aromatic hydrocarbons (PAH) in the atmosphere. PAH are formed mainly by anthropogenic processes, especially the combustion of organic fuels. PAH concentration in air will reflect the location of source emitters, with high concentrations corresponding with urban and industrial areas. PAH are however ubiquitous contaminants of the environment having been detected in remote areas of the world. This is thought to be due to long term transport in the atmosphere. PAH can also be subjected to chemical and/or photochemical change whilst resident in the atmosphere prior to their removal by either wet or dry deposition. 146 refs., 5 tabs

Analysis of the spatial dose according to the type of radiation source used in multi-bed hospital room

Energy Technology Data Exchange (ETDEWEB)

Jang, Dong Gun [Dept. of Nuclear Medicine, Dongnam Institute of Radiological and Medical Sciences Cancer center, Busan (Korea, Republic of); Kim, Jung Hoon [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of); Park, Eun Tae [Dept. of Radiation Oncology, Busan Paik Hospital, Inje University, Busan (Korea, Republic of)

2017-09-15

Medical radiation offers significant benefits in diagnosing and treating patients, but it also generates unnecessary radiation exposure to those nearby. Accordingly, the objective of the present study was to analyze spatial dose rate according to types of radiation source term in multi-bed hospital rooms occupied by patients and general public. MCNPX was used for geometric simulation of multi-bed hospital rooms and radiation source terms, while the radiation source terms were established as whole body bone scan patients and imaging using a portable X-ray generator. The results of simulation on whole body bone scan patients showed 3.46 μSv/hr to another patient position, while experimental results on imaging using a portable X-ray generator showed 1.47 × 10{sup -8} μSv/irradiation to another patient position in chest imaging and 2.97 × 10{sup -8} μSv/irradiation to another patient position in abdomen imaging. Multi-bed hospital room, unnecessary radiation generated in the surrounding patients, while legal regulations and systematic measures are needed for radiation exposure in multi-bed hospital rooms that are currently lacking in Korea.

Use of soft hydrothermal processing to improve and recycle bedding for laboratory animals.

Science.gov (United States)

Miyamoto, T; Li, Z; Kibushi, T; Yamasaki, N; Kasai, N

2008-10-01

Cage bedding for laboratory rodents can influence animal wellbeing and thus the experimental data. In addition, a large amount of used bedding containing excrement is discharged as medical waste from life science institutes and breeding companies. We developed a ground-breaking system to improve fresh bedding and recycle used bedding by applying a soft hydrothermal process with high-temperature and high-pressure dry steam. The system removes both harmful organic components and aromatic hydrocarbons that can affect animals' metabolism. The purpose of the present study was to evaluate the chemical and physical properties of the improved fresh bedding and the recycled used bedding treated by the system. The results showed that 68-99% of the predominant aromatic hydrocarbons were removed from fresh bedding treated at 0.35 MPa and 140 degrees C for 120 min ('improved bedding'). In addition, 59.4-99.0% of predominant harmful organic compounds derived from excrement were removed from used bedding treated at 0.45 MPa and 150 degrees C for 60 min ('recycled bedding'). The soft hydrothermal treatment increased the number of acidic functional groups on the bedding surface and gave it the high adsorptive efficiency of ammonia gas. Harmful substances such as microorganisms, heavy metals and pesticides decreased below the detection limit. The results clearly showed that the improved and recycled bedding is safer for laboratory rodents and has the potential to ameliorate conditions in primary and secondary enclosures (e.g. cages and animal rooms) used for maintaining laboratory animals. This process may be one of the most advanced techniques in providing an alternative to softwood and other bedding, economizing through the recycling of used bedding and reducing bedding waste from animal facilities.

Modeling of Antenna for Deep Target Hydrocarbon Exploration

Directory of Open Access Journals (Sweden)

Nadeem Nasir

2017-11-01

Full Text Available Nowadays control source electromagnetic method is used for offshore hydrocarbon exploration. Hydrocarbon detection in sea bed logging (SBL is a very challenging task for deep target hydrocarbon reservoir. Response of electromagnetic (EM field from marine environment is very low and it is very difficult to predict deep target reservoir below 2km from the sea floor. This work premise deals with modeling of new antenna for deep water deep target hydrocarbon exploration. Conventional and new EM antennas at 0.125Hz frequency are used in modeling for the detection of deep target hydrocarbon  reservoir.  The  proposed  area  of  the  seabed model   (40km ´ 40km   was   simulated   by using CST (computer simulation technology EM studio based on Finite Integration Method (FIM. Electromagnetic field components were compared at 500m target depth and it was concluded that Ex and Hz components shows better resistivity contrast. Comparison of conventional and new antenna for different target  depths  was  done in  our  proposed  model.  From  the results, it was observed that conventional antenna at 0.125Hz shows 70% ,86% resistivity contrast at target depth of 1000m where   as   new   antenna   showed   329%, 355%   resistivity contrast at the same target depth for Ex and Hz field respectively.  It  was  also  investigated  that  at  frequency of0.125Hz, new antenna gave 46% better delineation of hydrocarbon at 4000m target depth. This is due to focusing of electromagnetic waves by using new antenna. New antenna design gave 125% more extra depth than straight antenna for deep target hydrocarbon detection. Numerical modeling for straight  and  new antenna  was also done to know general equation for electromagnetic field behavior with target depth. From this numerical model it was speculated that this new antenna can detect up to 4.5 km target depth. This new EM antenna may open new frontiers for oil and gas

Identifying future directions for subsurface hydrocarbon migration research

Science.gov (United States)

Leifer, I.; Clark, J. F.; Luyendyk, B.; Valentine, D.

Subsurface hydrocarbon migration is important for understanding the input and impacts of natural hydrocarbon seepage on the environment. Great uncertainties remain in most aspects of hydrocarbon migration, including some basic mechanisms of this four-phase flow of tar, oil, water, and gas through the complex fracture-network geometry particularly since the phases span a wide range of properties. Academic, government, and industry representatives recently attended a workshop to identify the areas of greatest need for future research in shallow hydrocarbon migration.Novel approaches such as studying temporal and spatial seepage variations and analogous geofluid systems (e.g., geysers and trickle beds) allow deductions of subsurface processes and structures that remain largely unclear. Unique complexities exist in hydrocarbon migration due to its multiphase flow and complex geometry, including in-situ biological weathering. Furthermore, many aspects of the role of hydrocarbons (positive and negative) in the environment are poorly understood, including how they enter the food chain (respiration, consumption, etc.) and “percolate” to higher trophic levels. But understanding these ecological impacts requires knowledge of the emissions' temporal and spatial variability and trajectories.

Source apportionment of atmospheric polycyclic aromatic hydrocarbons (PAHs) in Palm Beach County, Florida.

Science.gov (United States)

Afshar-Mohajer, Nima; Wilson, Christina; Wu, Chang-Yu; Stormer, James E

2016-04-01

Due to concerns about adverse health effects associated with inhalation of atmospheric polycyclic aromatic hydrocarbons (PAHs), 30 ambient air samples were obtained at an air quality monitoring station in Palm Beach County, Florida, from March 2013 to March 2014. The ambient PAH concentration measurements and fractional emission rates of known sources were incorporated into a chemical mass balance model, CMB8.2, developed by EPA, to apportion contributions of three major PAH sources including preharvest sugarcane burning, mobile vehicles, and wildland fires. Strong association between the number of benzene rings and source contribution was found, and mobile vehicles were identified to be the prevailing source (contribution≥56%) for the observed PAHs concentration with lower molecular weights (four or fewer benzene rings) throughout the year. Preharvest sugarcane burning was the primary contributing source for PAHs with relatively higher molecular weights (five or more benzene rings) during the sugarcane burning season (from October to May of the next year). Source contribution of wildland fires varied among PAH compounds but was consistently lower than for sugarcane burning during the sugarcane harvest season. Determining the major sources responsible for ground-level PAHs serves as a tool to improving management strategies for PAH emitting sources and a step toward better protection of the health of residents in terms of exposure to PAHs. The results obtain insight into temporal dominance of PAH polluting sources for those residential areas located near sugarcane burning facilities and have implications beyond Palm Beach County, in areas with high concerns of PAHs and their linked sources. Source apportionment of atmospheric polycyclic hydrocarbons (PAHs) in Palm Beach County, Florida, meant to estimate contributions of major sources in PAH concentrations measured at Belle Glade City of Palm Beach County. Number of benzene rings was found to be the key parameter

Plasma devices for hydrocarbon reformation

KAUST Repository

Cha, Min Suk

2017-02-16

Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

The genetic source and timing of hydrocarbon formation in gas hydrate reservoirs in Green Canyon, Block GC955

Science.gov (United States)

Moore, M. T.; Darrah, T.; Cook, A.; Sawyer, D.; Phillips, S.; Whyte, C. J.; Lary, B. A.

2017-12-01

Although large volumes of gas hydrates are known to exist along continental slopes and below permafrost, their role in the energy sector and the global carbon cycle remains uncertain. Investigations regarding the genetic source(s) (i.e., biogenic, thermogenic, mixed sources of hydrocarbon gases), the location of hydrocarbon generation, (whether hydrocarbons formed within the current reservoir formations or underwent migration), rates of clathrate formation, and the timing of natural gas formation/accumulation within clathrates are vital to evaluate economic potential and enhance our understanding of geologic processes. Previous studies addressed some of these questions through analysis of conventional hydrocarbon molecular (C1/C2+) and stable isotopic (e.g., δ13C-CH4, δ2H-CH4, δ13C-CO2) composition of gases, water chemistry and isotopes (e.g., major and trace elements, δ2H-H2O, δ18O-H2O), and dissolved inorganic carbon (δ13C-DIC) of natural gas hydrate systems to determine proportions of biogenic and thermogenic gas. However, the effects from contributions of mixing, transport/migration, methanogenesis, and oxidation in the subsurface can complicate the first-order application of these techniques. Because the original noble gas composition of a fluid is preserved independent of microbial activity, chemical reactions, or changes in oxygen fugacity, the integration of noble gas data can provide both a geochemical fingerprint for sources of fluids and an additional insight as to the uncertainty between effects of mixing versus post-genetic modification. Here, we integrate inert noble gases (He, Ne, Ar, and associated isotopes) with these conventional approaches to better constrain the source of gas hydrate formation and the residence time of fluids (porewaters and natural gases) using radiogenic 4He ingrowth techniques in cores from two boreholes collected as part of the University of Texas led UT-GOM2-01 drilling project. Pressurized cores were extracted from

Hydrocarbon Prospectivity of Nigeria's Inland Basins: From the View Point of Organic Geochemistry and Organic Petrology

International Nuclear Information System (INIS)

Obaje, N. G.; Abubakar, M. B.; Jauro, A.; Tukur, A.; Wehner, H.

2003-01-01

The inland basins of Nigeria comprise the Anambra basin, the lower, middle and upper Benue trough, the southeastern sector of the Chad basin, the Mid-Niger (Bida) basin, and the Sokoto basin. Organic geochemical and organic petrologic studies indicate that coal beds constitute major potential source rocks in the whole of the Benue trough (Anambra basin inclusive). The generation and production of liquid and i gaseous hydrocarbons from coal beds presently is world-wide indisputable. In the Anambra basin, the coal beds in the Mamu Formation have TOC contents of up to 60.8wt%, mean Hydrogen Index (HI) of 364mgHC/gTOC, vitrinite reflectivity (Ro) of 0.54 to 0.56% and Tmax 430 to 433degrees C. Biomarker data indicate a dominance of high molecular weight : n-alkanes, very high pristane/phytane ratios, pronounced odd-over-even predominance (OEP), preponderance of C29 regular steranes but with also relatively high contents of C28. In the middle Benue trough, the coal beds of the Awgu Formation have TOC contents of up to 79.1 Owt%, Ro of 0.83 to 1.07%, and mean HI of 281 mgHC/gTOC; unimodal distributions of both low and high molecular weight n-alkanes with no obvious OEP, and a predominance of C29 steranes but also with relatively high contents of C27 and C28. Coal beds from the Lamja Formation in the upper Benue trough yielded TOC contents of up to 50.7wt% with HI of 184mgHC/gTOC, Ro of 0.70 to 0.73%, low and high molecular weights n- alkane dominance with an unpronounced OEP, high pristane/phytane ratios, and very high contents of C29 regular steranes. On a basinal evaluation level, incorporating source rock data from the other formations in the respective sectors, plots on the modified Van Krevelen diagram alongside biomarker and maceral data indicate good i to fair source rock qualities (oil and gas) in the Anambra basin and middle Benue trough; and fair to poor (gaseous to dry) in the upper Benue trough and the Chad basin, with sporadic good to fair source rock

Receptor modeling of C2─C7 hydrocarbon sources at an urban background site in Zurich, Switzerland: changes between 1993─1994 and 2005─2006

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S. Reimann

2008-05-01

Full Text Available Hourly measurements of 13 volatile hydrocarbons (C2–C7 were performed at an urban background site in Zurich (Switzerland in the years 1993–1994 and again in 2005–2006. For the separation of the volatile organic compounds by gas-chromatography (GC, an identical chromatographic column was used in both campaigns. Changes in hydrocarbon profiles and source strengths were recovered by positive matrix factorization (PMF. Eight and six factors could be related to hydrocarbon sources in 1993–1994 and in 2005–2006, respectively. The modeled source profiles were verified by hydrocarbon profiles reported in the literature. The source strengths were validated by independent measurements, such as inorganic trace gases (NOx, CO, SO2, methane (CH4, oxidized hydrocarbons (OVOCs and meteorological data (temperature, wind speed etc.. Our analysis suggests that the contribution of most hydrocarbon sources (i.e. road traffic, solvents use and wood burning decreased by a factor of about two to three between the early 1990s and 2005–2006. On the other hand, hydrocarbon losses from natural gas leakage remained at relatively constant levels (−20%. The estimated emission trends are in line with the results from different receptor-based approaches reported for other European cities. Their differences to national emission inventories are discussed.

Identifying risk sources of air contamination by polycyclic aromatic hydrocarbons.

Science.gov (United States)

Huzlik, Jiri; Bozek, Frantisek; Pawelczyk, Adam; Licbinsky, Roman; Naplavova, Magdalena; Pondelicek, Michael

2017-09-01

This article is directed to determining concentrations of polycyclic aromatic hydrocarbons (PAHs), which are sorbed to solid particles in the air. Pollution sources were identified on the basis of the ratio of benzo[ghi]perylene (BghiPe) to benzo[a]pyrene (BaP). Because various important information is lost by determining the simple ratio of concentrations, least squares linear regression (classic ordinary least squares regression), reduced major axis, orthogonal regression, and Kendall-Theil robust diagnostics were utilized for identification. Statistical evaluation using all aforementioned methods demonstrated different ratios of the monitored PAHs in the intervals examined during warmer and colder periods. Analogous outputs were provided by comparing gradients of the emission factors acquired from the measured concentrations of BghiPe and BaP in motor vehicle exhaust gases. Based on these outputs, it was possible plausibly to state that the influence of burning organic fuels in heating stoves is prevalent in colder periods whereas in warmer periods transport was the exclusive source because other sources of PAH emissions were not found in the examined locations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anaerobic transformation of chlorinated hydrocarbons in a packed-bed reactor

NARCIS (Netherlands)

Best, Jappe Hinco de

1999-01-01

Chlorinated aliphatic hydrocarbons belong to the most frequently found contaminants in soil. Because of their toxicity and persistence, they are a potential threat to human health and the diversity of ecosystems. For the cleanup of soils contaminated with these compounds, biological degradation by

Receptor modeling for source apportionment of polycyclic aromatic hydrocarbons in urban atmosphere.

Science.gov (United States)

Singh, Kunwar P; Malik, Amrita; Kumar, Ranjan; Saxena, Puneet; Sinha, Sarita

2008-01-01

This study reports source apportionment of polycyclic aromatic hydrocarbons (PAHs) in particulate depositions on vegetation foliages near highway in the urban environment of Lucknow city (India) using the principal components analysis/absolute principal components scores (PCA/APCS) receptor modeling approach. The multivariate method enables identification of major PAHs sources along with their quantitative contributions with respect to individual PAH. The PCA identified three major sources of PAHs viz. combustion, vehicular emissions, and diesel based activities. The PCA/APCS receptor modeling approach revealed that the combustion sources (natural gas, wood, coal/coke, biomass) contributed 19-97% of various PAHs, vehicular emissions 0-70%, diesel based sources 0-81% and other miscellaneous sources 0-20% of different PAHs. The contributions of major pyrolytic and petrogenic sources to the total PAHs were 56 and 42%, respectively. Further, the combustion related sources contribute major fraction of the carcinogenic PAHs in the study area. High correlation coefficient (R2 > 0.75 for most PAHs) between the measured and predicted concentrations of PAHs suggests for the applicability of the PCA/APCS receptor modeling approach for estimation of source contribution to the PAHs in particulates.

Autothermal reforming of liquid hydrocarbons for H{sub 2} production

Energy Technology Data Exchange (ETDEWEB)

Palm, C.; Montel, S.; Cremer, P.; Peters, R.; Stolten, D. [Forschungszentrum Juelich GmbH (Germany). Inst. for Materials and Processes in Energy Systems IWV-3: Process Engineering

2001-07-01

The process of autothermal reforming of hydrocarbons can be used for the production of hydrogen within a fuel cell system. The application of three precious metal catalysts for the autothermal reforming of alkane mixtures with boiling ranges between 235 and 325 C was examined. The experiments were carried out at n(O{sub 2})/n(C) = 0.40, n(H{sub 2}O)/n(C) = 2.20, a catalyst bed temperature between 730 and 570 C and a hydrocarbon feed of 30 g/h. The catalysts yielded different hydrocarbon conversions, which can be explained by differences in the activity for the steam reforming reaction. The most active catalyst was also successfully utilized in the conversion of 400 g/h hydrocarbon feed. (orig.)

The distribution and sources of polycyclic aromatic hydrocarbons in shallow groundwater from an alluvial-diluvial fan of the Hutuo River in North China

Science.gov (United States)

Wang, Jincui; Zhao, Yongsheng; Sun, Jichao; Zhang, Ying; Liu, Chunyan

2018-06-01

This paper has investigated the concentration and distribution of polycyclic aromatic hydrocarbons in shallow groundwater from an alluvial-diluvial fan of the Hutuo River in North China. Results show that the concentration levels of 16 priority polycyclic aromatic hydrocarbons range from 0 to 92.06 ng/L, do not conform to drinking water quality standards in China (GB 5749- 2006). However, the concentration figures of priority polycyclic aromatic hydrocarbons are much lower than that of other studies conducted elsewhere in China. In addition, highly-concentrated polycyclic aromatic hydrocarbons (50-92 ng/L) are fragmentarily distributed. The composition of polycyclic aromatic hydrocarbons from this study indicates that low molecular polycyclic aromatic hydrocarbons are predominant in groundwater samples, medium molecular compounds occur at low concentrations, and high molecular hydrocarbons are not detected. The polycyclic aromatic hydrocarbon composition in groundwater samples is basically the same as that of gaseous samples in the atmosphere in this study. Therefore, the atmospheric input is assumed to be an important source of polycyclic aromatic hydrocarbons, no less than wastewater discharge, adhesion on suspended solids, and surface water leakage. Ratios of specific polycyclic aromatic hydrocarbons demonstrate that they mainly originate from wood or coal combustion as well as natural gas and partially from petroleum according to the result of principal component analysis. On the whole, conclusions are drawn that the contamination sources of these polycyclic aromatic hydrocarbons are likely petrogenic and pyrolytic inputs. Future investigations by sampling topsoil, vadose soil, and the atmosphere can further verify aforementioned conclusions.

Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

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Olek Malgorzata

2013-01-01

Full Text Available Abstract Background The process of thermal decomposition of dichloromethane (DCM and chlorobenzene (MCB during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. Conclusions Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%.

Hydrocarbon Plume Dynamics in the Worldś Most Spectacular Hydrocarbon Seeps, Santa Barbara Channel, California

Science.gov (United States)

Mau, S.; Reed, J.; Clark, J.; Valentine, D.

2006-12-01

Large quantities of natural gas are emitted from the seafloor into the coastal ocean near Coal Oil Point, Santa Barbara Channel (SBC), California. Methane, ethane, and propane were quantified in the surface water at 79 stations in a 270 km2 area in order to map the surficial hydrocarbon plume and to quantify air-sea exchange of these gases. A time series was initiated for 14 stations to identify the variability of the mapped plume, and biologically-mediated oxidation rates of methane were measured to quantify the loss of methane in surface water. The hydrocarbon plume was found to comprise ~70 km2 and extended beyond study area. The plume width narrowed from 3 km near the source to 0.7 km further from the source, and then expanded to 6.7 km at the edge of the study area. This pattern matches the cyclonic gyre which is the normal current flow in this part of the Santa Barbara Channel - pushing water to the shore near the seep field and then broadening the plume while the water turns offshore further from the source. Concentrations of gaseous hydrocarbons decrease as the plume migrates. Time series sampling shows similar plume width and hydrocarbon concentrations when normal current conditions prevail. In contrast, smaller plume width and low hydrocarbon concentrations were observed when an additional anticyclonic eddy reversed the normal current flow, and a much broader plume with higher hydrocarbon concentrations was observed during a time of diminished speed within the current gyre. These results demonstrate that surface currents control hydrocarbon plume dynamics in the SBC, though hydrocarbon flux to the atmosphere is likely less dependent on currents. Estimates of air- sea hydrocarbon flux and biological oxidation rates will also be presented.

Potential sources of hydrocarbons and their microbial degradation in sediments from the deep geothermal Lusi site, Indonesia

Science.gov (United States)

Krueger, Martin; Mazzini, Adriano; Scheeder, Georg; Blumenberg, Martin

2017-04-01

The Lusi eruption represents one of the largest ongoing sedimentary hosted geothermal systems, which started in 2006 following an earthquake on Java Island. Since then it has been continuously producing hot and hydrocarbon rich mud from a central crater with peaks reaching 180.000 m3 per day. Numerous investigations focused on the study of microbial communities which thrive at offshore methane and oil seeps and mud volcanoes, however very little has been done on onshore seeping structures. Lusi represents a unique opportunity to complete a comprehensive study of onshore microbial communities fed by the seepage of CH4 as well as of liquid hydrocarbons originating from one or more km below the surface. While the source of the methane at Lusi is unambiuous, the origin of the seeping oil is still discussed. Both, source and maturity estimates from biomarkers, are in favor of a type II/III organic matter source. Likely the oils were formed from the studied black shales (deeper Ngimbang Fm.) which contained a Type III component in the Type II predominated organic matter. In all samples large numbers of active microorganisms were present. Rates for aerobic methane oxidation were high, as was the potential of the microbial communities to degrade different hydrocarbons. The data suggests a transition of microbial populations from an anaerobic, hydrocarbon-driven metabolism in fresher samples from center or from small seeps to more generalistic, aerobic microbial communities in older, more consolidated sediments. Ongoing microbial activity in crater sediment samples under high temperatures (80-95C) indicate a deep origin of the involved microorganisms. First results of molecular analyses of the microbial community compositions confirm the above findings. This study represents an initial step to better understand onshore seepage systems and provides an ideal analogue for comparison with the better investigated offshore structures.

Source apportionment of polycyclic aromatic hydrocarbons in surface soil in Tianjin, China

International Nuclear Information System (INIS)

Zuo, Q.; Duan, Y.H.; Yang, Y.; Wang, X.J.; Tao, S.

2007-01-01

Principal component analysis and multiple linear regression were applied to apportion sources of polycyclic aromatic hydrocarbons (PAHs) in surface soils of Tianjin, China based on the measured PAH concentrations of 188 surface soil samples. Four principal components were identified representing coal combustion, petroleum, coke oven plus biomass burning, and chemical industry discharge, respectively. The contributions of major sources were quantified as 41% from coal, 20% from petroleum, and 39% from coking and biomass, which are compatible with PAH emissions estimated based on fuel consumption and emission factors. When the study area was divided into three zones with distinctive differences in soil PAH concentration and profile, different source features were unveiled. For the industrialized Tanggu-Hangu zone, the major contributors were coking (43%), coal (37%) and vehicle exhaust (20%). In rural area, however, in addition to the three main sources, biomass burning was also important (13%). In urban-suburban zone, incineration accounted for one fourth of the total. - PAHs in surface soil of Tianjin were apportioned and coal combustion, vehicle exhaust, coke production, and biomass burning were found to be the major sources

Gypsum as a bedding source for broiler chickens

Science.gov (United States)

Three trials examined the feasibility of flue gas desulfurization gypsum as a bedding material for raising broilers. Gypsum was used alone, under or on top of pine shavings and pine bark. Test materials were placed as bedding in pens to simulate commercial broiler production through three growout cy...

Problems of hydrocarbon resources development in new bedding zones

International Nuclear Information System (INIS)

Egorov, O.I.; Koszhanov, A.K.

1997-01-01

Intensive exploring geological surveying works were carried out for revealing of fuel resources in South Kazakhstan. Number of complex gas deposits - Ajrakty, Amangel'dy, Kumyrly and others as well as Northern Usharly and Usharal-Kemirtobe deposits of nitrogen-helium gas are recovered. Introduction its into operation has significant importance in consequence of urgent fuel deficit in region. Basic way of guaranteed gas supply to industry and population of South Kazakhstan is connected with own hydrocarbon fields development

The bedding of laboratory animals as a source of airborne contaminants.

Science.gov (United States)

Kaliste, E; Linnainmaa, M; Meklin, T; Torvinen, E; Nevalainen, A

2004-01-01

In work environments with laboratory animals, the bedding of animals binds the excreta as well as other compounds originating from the animals and their environment. These may be generated into the ambient air when the personnel handle bedding in different procedures. This study compares the dustiness of different types of six clean and four soiled beddings from rat or mouse cages. The dust generation of clean bedding varied from beddings decreased, increased or stayed the same, depending on the type of bedding and animal species. A decrease in dustiness was, however, more common. The levels in the soiled beddings varied from bedding, the contents of bedding used in mouse, rat or rabbit cages were analysed for mesophilic bacteria and fungi, mycobacteria and endotoxins. All of these contaminants were variably found in the bedding samples, the maximal concentrations for bacteria were >6 500 000 colony-forming units (cfu)/g, for fungi 212 000 cfu/g, and for endotoxins 6500 ng/g (81 000 EU/g). The results showed that the bedding of laboratory animals may contain biologically effective compounds, and that these may be distributed into the ambient air depending on the characteristics of the bedding material. The dustiness of different bedding types is an important factor affecting the amount and quality of the occupational exposure of the personnel to airborne contaminants.

Session 2: economic and environmental aspects of the different sources of hydrocarbons

International Nuclear Information System (INIS)

Susbielles, G.

2006-01-01

Here are given the summaries of the speeches of Mr Bernard Montaron (Schlumberger): the petroleum recovery ratios: a technical challenge for the energetic stake; of Mr Xavier Preel (Total): the non conventional petroleums; of Mr Guy de Kort (Shell): gas to liquids; and of Mrs Nathalie Alazard (IFP): the fuels coming from biomass. All these speeches have been presented at the AFTP petroleum yearly days (12-13 October 2005) during the session 2 concerning the economical and environmental aspects of the different sources of hydrocarbons. (O.M.)

Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment.

Science.gov (United States)

Mishra, Nitika; Ayoko, Godwin A; Morawska, Lidia

2016-01-01

Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Particulate-bound polycyclic aromatic hydrocarbon sources and determinants in residential homes.

Science.gov (United States)

Cattaneo, Andrea; Fermo, Paola; Urso, Patrizia; Perrone, Maria Grazia; Piazzalunga, Andrea; Tarlassi, Jessica; Carrer, Paolo; Cavallo, Domenico Maria

2016-11-01

Human exposure to polycyclic aromatic hydrocarbons (PAHs) in indoor environments can be particularly relevant because people spend most of their time inside buildings, especially in homes. This study aimed to investigate the most important particle-bound PAH sources and exposure determinants in PM 2.5 samples collected in 19 homes located in northern Italy. Complementary information about ion content in PM 10 was also collected in 12 of these homes. Three methods were used for the identification of PAH sources and determinants: diagnostic ratios with principal component and hierarchical cluster analyses (PCA and HCA), chemical mass balance (CMB) and linear mixed models (LMMs). This combined and tiered approach allowed the infiltration of outdoor PAHs into indoor environments to be identified as the most important source in winter, with a relevant role played by biomass burning and traffic exhausts to be identified as a general source of PAHs in both seasons. Tobacco smoke exhibited an important impact on PAH levels in smokers' homes, whereas in the whole sample, cooking food and natural gas sources played a minor or negligible role. Nitrate, sulfate and ammonium were the main inorganic constituents of indoor PM 10 owing to the secondary formation of ammonium sulfates and nitrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fission Product Transport and Source Terms in HTRs: Experience from AVR Pebble Bed Reactor

Directory of Open Access Journals (Sweden)

Rainer Moormann

2008-01-01

Full Text Available Fission products deposited in the coolant circuit outside of the active core play a dominant role in source term estimations for advanced small pebble bed HTRs, particularly in design basis accidents (DBA. The deposited fission products may be released in depressurization accidents because present pebble bed HTR concepts abstain from a gas tight containment. Contamination of the circuit also hinders maintenance work. Experiments, performed from 1972 to 88 on the AVR, an experimental pebble bed HTR, allow for a deeper insight into fission product transport behavior. The activity deposition per coolant pass was lower than expected and was influenced by fission product chemistry and by presence of carbonaceous dust. The latter lead also to inconsistencies between Cs plate out experiments in laboratory and in AVR. The deposition behavior of Ag was in line with present models. Dust as activity carrier is of safety relevance because of its mobility and of its sorption capability for fission products. All metal surfaces in pebble bed reactors were covered by a carbonaceous dust layer. Dust in AVR was produced by abrasion in amounts of about 5 kg/y. Additional dust sources in AVR were ours oil ingress and peeling of fuel element surfaces due to an air ingress. Dust has a size of about 1  m, consists mainly of graphite, is partly remobilized by flow perturbations, and deposits with time constants of 1 to 2 hours. In future reactors, an efficient filtering via a gas tight containment is required because accidents with fast depressurizations induce dust mobilization. Enhanced core temperatures in normal operation as in AVR and broken fuel pebbles have to be considered, as inflammable dust concentrations in the gas phase.

Hydrocarbon Source Rock Potential of the Sinamar Formation, Muara Bungo, Jambi

Directory of Open Access Journals (Sweden)

Moh. Heri Hermiyanto Zajuli

2014-07-01

Full Text Available DOI: 10.17014/ijog.v1i1.175The Oligocene Sinamar Formation consists of shale, claystone, mudstone, sandstone, conglomeratic sandstone, and intercalation of coal seams. The objective of study was to identify the hydrocarbon source rock potential of the Sinamar Formation based on geochemichal characteristics. The analyses were focused on fine sediments of the Sinamar Formation comprising shale, claystone, and mudstone. Primary data collected from the Sinamar Formation well and outcrops were analyzed according to TOC, pyrolisis analysis, and gas chromatography - mass spectometry of normal alkanes that include isoprenoids and sterane. The TOC value indicates a very well category. Based on TOC versus Pyrolysis Yields (PY diagram, the shales of Sinamar Formation are included into oil prone source rock potential with good to excellent categories. Fine sediments of the Sinamar Formation tend to produce oil and gas originated from kerogen types I and III. The shales tend to generate oil than claystone and mudstone and therefore they are included into a potential source rock. 

Receptor Model Source Apportionment of Nonmethane Hydrocarbons in Mexico City

Directory of Open Access Journals (Sweden)

V. Mugica

2002-01-01

Full Text Available With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas, asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

Energy Technology Data Exchange (ETDEWEB)

Badger, Phillip C.; Dunn, Jr., Kenneth J.

2015-09-01

A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

Reassessment of the hydrocarbons in Prince William Sound and the Gulf of Alaska : identifying the source using partial least squares

International Nuclear Information System (INIS)

Mudge, S.M.

2001-01-01

Since the Exxon Valdez oil spill in Prince William Sound, Alaska there has been much discussion regarding the clean-up and long term fate of the oil. There has also been debate regarding the origin of the background hydrocarbons present within Prince William Sound (PWS) and the Gulf of Alaska (GoA). There is evidence that background (pre-spill) hydrocarbons may come from either nearby coal deposits or from natural oil seeps and eroding source rocks in the region. This paper presented a study in which the multivariate statistical methodology of the Partial Least Squares (PLS) was used to reassess the percentage contribution of coal, seep oil, shales and rivers to the hydrocarbon loading in the GoA. Data was provided by researchers at the National Ocean and Atmospheric Administration (NOAA) and the Bowdoin College, for Exxon. The data was analysed using selected sites as sources in order to develop signatures. The signatures were based on 40 and 136 compounds respectively, including the polyaromatic hydrocarbon (PAH) and terpane biomarkers from the Exxon data. The key components describing the sources were fitted to the data for other sites around the GoA to determine the proportion of the variability described by each source. The large complex datasets can be used to develop complex fingerprints for sources rather than using relatively simplistic ratios between selected compounds. The results indicate that 30 per cent of the signature is common between each source and that the small PAHs are the best diagnostic compounds in the model for the oil signature and the large PAHs are good for coal. Naphthalene, methyl and dimethyl naphthalene are the best markers for the seep oil signature. For the pre-spill background, coals and shales are best defined by the larger PAHs such as perylene and benzo(ghi)perylene. In general, the average partitioning between the two sources across all the sampling sites within the region indicated that 53 per cent is attributable to the

Chemical fingerprinting of hydrocarbon-contamination in soil.

Science.gov (United States)

Boll, Esther S; Nejrup, Jens; Jensen, Julie K; Christensen, Jan H

2015-03-01

Chemical fingerprinting analyses of 29 hydrocarbon-contaminated soils were performed to assess the soil quality and determine the main contaminant sources. The results were compared to an assessment based on concentrations of the 16 priority polycyclic aromatic hydrocarbons pointed out by the U.S. Environmental Protection Agency (EPAPAH16) and total petroleum hydrocarbon (TPH). The chemical fingerprinting strategy proposed in this study included four tiers: (i) qualitative analysis of GC-FID chromatograms, (ii) comparison of the chemical composition of both un-substituted and alkyl-substituted polycyclic aromatic compounds (PACs), (iii) diagnostic ratios of selected PACs, and (iv) multivariate data analysis of sum-normalized PAC concentrations. The assessment criteria included quantitative analysis of 19 PACs and C1-C4 alkyl-substituted homologues of naphthalene, fluorene, dibenzothiophene, phenanthrene, pyrene, and chrysene; and 13 oxygenated polycyclic aromatic compounds (O-PACs). The chemical composition of un-substituted and alkyl-substituted PACs and visual interpretation of GC-FID chromatograms were in combination successful in differentiating pyrogenic and petrogenic hydrocarbon sources and in assessing weathering trends of hydrocarbon contamination in the soils. Multivariate data analysis of sum-normalized concentrations could as a stand-alone tool distinguish between hydrocarbon sources of petrogenic and pyrogenic origin, differentiate within petrogenic sources, and detect weathering trends. Diagnostic ratios of PACs were not successful for source identification of the heavily weathered hydrocarbon sources in the soils. The fingerprinting of contaminated soils revealed an underestimation of PACs in petrogenic contaminated soils when the assessment was based solely on EPAPAH16. As alkyl-substituted PACs are dominant in petrogenic sources, the evaluation of the total load of PACs based on EPAPAH16 was not representative. Likewise, the O-PACs are not

Observations on sediment sources in the Lower Athabasca River basin: implications of natural hydrocarbons inputs from oil sands deposits

International Nuclear Information System (INIS)

Conly, F.M.

1999-01-01

Government, industry and public concern exists over the environmental consequences of the development of the oil sand deposits in the McMurray Formation in the lower Athabasca River basin, Alberta. The impact of this development is unclear and is undergoing investigation. Investigations to date have focussed on the nature of the effluent produced by the extraction industry and its effect on biotic systems, and on the spatial distribution of hydrocarbon contaminants associated with deposited fluvial sediments. Natural hydrocarbon outcrops may be responsible for observed biomarker responses in areas not exposed to industrial effluent. Given this source of hydrocarbons and doubt concerning its environmental impact, it is difficult to ascertain the impact of oil extraction activities within a fluvial system. A study was conducted to determine the nature and extent of natural hydrocarbon releases within the context of the sediment regime of the lower Athabasca River basin. A description is included of observations from the field and a context is set up for assessing sediment-bound hydrocarbon contaminants in the lower Athabasca River basin. Abstract only included

Petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in Hong Kong marine sediments

International Nuclear Information System (INIS)

Zheng, G.J.; Richardson, B.J.

1999-01-01

A total of 20 surficial sediment samples, obtained from Hong Kong coastal waters, were analysed for petroleum hydrocarbons (PHCs) and a suite of 15 polycyclic aromatic hydrocarbons (PAHs). The results indicate that Hong Kong coastal sediments are often seriously polluted with petroleum related hydrocarbons. This is especially so in heavily urbanised or industrialized localities, such as Kowloon Bay (Victoria Harbour), Tsing Yi North and Tolo Harbour. Petroleum hydrocarbon pollutants in marine sediments are believed to be mainly derived from the transportation of oil, shipping activities, spillages, and industrial, stormwater and waste wastewater discharge. The ratio of unresolved complex mixture (UCM) to n-alkanes, carbon preference index (CPI), and n-C 16 values indicate that the main contribution to petroleum hydrocarbon contamination is via oil and its products. Pollutant sources appear to be stable and continuing when compared with previous data. (author)

Aliphatic hydrocarbon and polycyclic aromatic hydrocarbon geochemistry of twelve major rivers in the Northwest Territories

International Nuclear Information System (INIS)

Backus, S.; Swyripa, M.; Peddle, J.; Jeffries, D.S.

1995-01-01

Suspended sediment and water samples collected from twelve major rivers in the Northwest Territories were analyzed for aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) to assess the sources and transport of hydrocarbons entering the Arctic Ocean. Three stations on the Mackenzie River and one station near the mouth of eleven other northern rivers were selected for sampling. Samples were collected on the Mackenzie River on four occasions to characterize spring, summer and fall flow conditions and once on the remaining eleven rivers during high flow conditions. The Mackenzie River is distinctively different then the other eleven rivers. Naturally occurring hydrocarbons predominate in the river. These hydrocarbons include biogenic alkanes, diagenic PAHs, petrogenic alkanes, and PAHs from oil seeps and/or bitumens. Anthropogenic inputs of PAHs are low as indicated by low concentrations of combustion PAHs. Alkyl PAH distributions indicate that a significant component of the lower molecular weight PAH fraction is petrogenic. The majority of the high molecular weight PAHs, together with the petrogenic PAHs have a principal source in the Mackenzie River

Steam reforming of heptane in a fluidized bed membrane reactor

Science.gov (United States)

Rakib, Mohammad A.; Grace, John R.; Lim, C. Jim; Elnashaie, Said S. E. H.

n-Heptane served as a model compound to study steam reforming of naphtha as an alternative feedstock to natural gas for production of pure hydrogen in a fluidized bed membrane reactor. Selective removal of hydrogen using Pd 77Ag 23 membrane panels shifted the equilibrium-limited reactions to greater conversion of the hydrocarbons and lower yields of methane, an intermediate product. Experiments were conducted with no membranes, with one membrane panel, and with six panels along the height of the reactor to understand the performance improvement due to hydrogen removal in a reactor where catalyst particles were fluidized. Results indicate that a fluidized bed membrane reactor (FBMR) can provide a compact reformer for pure hydrogen production from a liquid hydrocarbon feedstock at moderate temperatures (475-550 °C). Under the experimental conditions investigated, the maximum achieved yield of pure hydrogen was 14.7 moles of pure hydrogen per mole of heptane fed.

Potential hydrocarbon producing species of Western Ghats, Tamil Nadu, India

Energy Technology Data Exchange (ETDEWEB)

Augustus, G.D.P.S.; Jayabalan, M.; Rajarathinam, K. [Research Centre in Bombay, V.H.N.S.N. College, Virudhunagar (India); Ray, A.K. [Sardar Patel Univ., Anand (India). Dept. of Chemistry; Seiler, G.J. [USDA, ARS, Northern Crop Science Lab., Fargo, ND (United States)

2002-09-01

The decline in the world supplies of hydrocarbons has led to the search for alternate sources of fuel and chemicals. Plant species are potential sources of hydrocarbons. Large-scale screening of plants growing in the Western Ghats, Tamil Nadu, India was conducted to assess the hydrocarbon production and the type of isoprene compound(s) present. Three species contained more than 3% hydrocarbon. Sarcostemma brevistigma had the highest concentration of hydrocarbon with 3.6%. Seven species contained more than 2% of hydrocarbons among the plant species screened. The hydrocarbon fraction of Ficus elastica (leaf) had a gross heat value of 9834 cal/g (41.17 MJ/kg), which is close to the caloric value of fuel oil. Six hydrocarbon fractions contained gross heat values of more than 9000 cal/g (37.68 MJ/kg). Of the 13 species hydrocarbon fraction analysed, seven species contained cis-polyisoprene compounds, while two species contained trans-polyisoprenes. Cis and trans polyisoprenes are potential alternative energy sources for fuel and/or as industrial raw materials. (author)

Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall.

Science.gov (United States)

Zhang, Wei; Zhang, Shucai; Wan, Chao; Yue, Dapan; Ye, Youbin; Wang, Xuejun

2008-06-01

Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.

Sources and distribution of aromatic hydrocarbons in a tropical marine protected area estuary under influence of sugarcane cultivation.

Science.gov (United States)

Arruda-Santos, Roxanny Helen de; Schettini, Carlos Augusto França; Yogui, Gilvan Takeshi; Maciel, Daniele Claudino; Zanardi-Lamardo, Eliete

2018-05-15

Goiana estuary is a well preserved marine protected area (MPA) located on the northeastern coast of Brazil. Despite its current state, human activities in the watershed represent a potential threat to long term local preservation. Dissolved/dispersed aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments across the estuarine salt gradient. Concentration of aromatic hydrocarbons was low in all samples. According to results, aromatic hydrocarbons are associated to suspended particulate matter (SPM) carried to the estuary by river waters. An estuarine turbidity maximum (ETM) was identified in the upper estuary, indicating that both sediments and contaminants are trapped prior to an occasional export to the adjacent sea. PAHs distribution in sediments were associated with organic matter and mud content. Diagnostic ratios indicated pyrolytic processes as the main local source of PAHs that are probably associated with sugarcane burning and combustion engines. Low PAH concentrations probably do not cause adverse biological effects to the local biota although their presence indicate anthropogenic contamination and pressure on the Goiana estuary MPA. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of oil hydrocarbon fingerprinting and identification techniques

International Nuclear Information System (INIS)

Wang Zhendi; Fingas, Merv F.

2003-01-01

Oil, refined product, and pyrogenic hydrocarbons are the most frequently discovered contaminants in the environment. To effectively determine the fate of spilled oil in the environment and to successfully identify source(s) of spilled oil and petroleum products is, therefore, extremely important in many oil-related environmental studies and liability cases. This article briefly reviews the recent development of chemical analysis methodologies which are most frequently used in oil spill characterization and identification studies and environmental forensic investigations. The fingerprinting and data interpretation techniques discussed include oil spill identification protocol, tiered analytical approach, generic features and chemical composition of oils, effects of weathering on hydrocarbon fingerprinting, recognition of distribution patterns of petroleum hydrocarbons, oil type screening and differentiation, analysis of 'source-specific marker' compounds, determination of diagnostic ratios of specific oil constituents, stable isotopic analysis, application of various statistical and numerical analysis tools, and application of other analytical techniques. The issue of how biogenic and pyrogenic hydrocarbons are distinguished from petrogenic hydrocarbons is also addressed

Biogeochemistry of Halogenated Hydrocarbons

Science.gov (United States)

Adriaens, P.; Gruden, C.; McCormick, M. L.

2003-12-01

Halogenated hydrocarbons originate from both natural and industrial sources. Whereas direct anthropogenic emissions to the atmosphere and biosphere are often easy to assess, particularly when they are tied to major industrial activities, the attribution of emissions to other human activities (e.g., biomass burning), diffuse sources (e.g., atmospheric discharge, run off), and natural production (e.g., soils, fungi, algae, microorganisms) are difficult to quantify. The widespread occurrence of both alkyl and aryl halides in groundwater, surface water, soils, and various trophic food chains, even those not affected by known point sources, suggests a substantial biogeochemical cycling of these compounds (Wania and Mackay, 1996; Adriaens et al., 1999; Gruden et al., 2003). The transport and reactive fate mechanisms controlling their reactivity are compounded by the differences in sources of alkyl-, aryl-, and complex organic halides, and the largely unknown impact of biogenic processes, such as enzymatically mediated halogenation of organic matter, fungal production of halogenated hydrocarbons, and microbial or abiotic transformation reactions (e.g., Asplund and Grimvall, 1991; Gribble, 1996; Watling and Harper, 1998; Oberg, 2002). The largest source may be the natural halogenation processes in the terrestrial environment, as the quantities detected often exceed the amount that can be explained by human activities in the surrounding areas ( Oberg, 1998). Since biogeochemical processes result in the distribution of a wide range of halogenated hydrocarbon profiles, altered chemical structures, and isomer distributions in natural systems, source apportionment (or environmental forensics) can often only be resolved using multivariate statistical methods (e.g., Goovaerts, 1998; Barabas et al., 2003; Murphy and Morrison, 2002).This chapter will describe the widespread occurrence of halogenated hydrocarbons, interpret their distribution and biogeochemical cycling in light of

Distribution and sources of n-alkanes and polycyclic aromatic hydrocarbons in shellfish of the Egyptian Red Sea coast

Directory of Open Access Journals (Sweden)

Ahmed El Nemr

2016-06-01

Full Text Available Aromatic hydrocarbons and n-alkanes were analyzed in shellfish collected from 13 different sites along the Egyptian Red Sea coast. All samples were analyzed for n-alkanes (C8–C40 and polycyclic aromatic hydrocarbons (EPA list of PAHs. n-Alkanes in shellfish samples from 13 locations were found to be in the range of 71.0–701.1 ng/g with a mean value of 242.2 ± 192.1 ng/g dry wt. Different indices were calculated for the n-alkanes to assess their sources. These were carbon preference index (CPI, average chain length (ACL, terrigenous/aquatic ratio (TAR, natural n-alkane ratio (NAR and proxy ratio (Paq. Most of the collected samples of n-alkanes were discovered to be from natural sources. Aromatic hydrocarbons (16 PAHs from 13 sites varied between 1.3 and 160.9 ng/g with an average of 47.9 ± 45.5 ng/g dry wt. Benzo(apyrine (BaP, a cancer risk assessment, was calculated for the PAHs and resulted in ranges between 0.08 and 4.47 with an average of 1.25 ng/g dry wt.

Problems in the fingerprints based polycyclic aromatic hydrocarbons source apportionment analysis and a practical solution.

Science.gov (United States)

Zou, Yonghong; Wang, Lixia; Christensen, Erik R

2015-10-01

This work intended to explain the challenges of the fingerprints based source apportionment method for polycyclic aromatic hydrocarbons (PAH) in the aquatic environment, and to illustrate a practical and robust solution. The PAH data detected in the sediment cores from the Illinois River provide the basis of this study. Principal component analysis (PCA) separates PAH compounds into two groups reflecting their possible airborne transport patterns; but it is not able to suggest specific sources. Not all positive matrix factorization (PMF) determined sources are distinguishable due to the variability of source fingerprints. However, they constitute useful suggestions for inputs for a Bayesian chemical mass balance (CMB) analysis. The Bayesian CMB analysis takes into account the measurement errors as well as the variations of source fingerprints, and provides a credible source apportionment. Major PAH sources for Illinois River sediments are traffic (35%), coke oven (24%), coal combustion (18%), and wood combustion (14%). Copyright © 2015. Published by Elsevier Ltd.

Task 8: Evaluation of hydrocarbon potential

International Nuclear Information System (INIS)

Cashman, P.H.; Trexler, J.H. Jr.

1994-01-01

Our studies focus on the stratigraphy of Late Devonian to early Pennsylvanian rocks at the NTS, because these are the best potential hydrocarbon source rocks in the vicinity of Yucca Mountain. In the last year, our stratigraphic studies have broadened to include the regional context for both the Chainman and the Eleana formations. New age data based on biostratigraphy constrain the age ranges of both Chainman and Eleana; accurate and reliable ages are essential for regional correlation and for regional paleogeographic reconstructions. Source rock analyses throughout the Chainman establish whether these rocks contained adequate organic material to generate hydrocarbons. Maturation analyses of samples from the Chainman determine whether the temperature history has been suitable for the generation of liquid hydrocarbons. Structural studies are aimed at defining the deformation histories and present position of the different packages of Devonian - Pennsylvanian rocks. This report summarizes new results of our structural, stratigraphic and hydrocarbon source rock potential studies at the Nevada Test Site and vicinity. Stratigraphy is considered first, with the Chainman Shale and Eleana Formation discussed separately. New biostratigraphic results are included in this section. New results from our structural studies are summarized next, followed by source rock and maturation analyses of the Chainman Shale. Directions for future work are included where appropriate

Novel Photocatalytic Reactor Development for Removal of Hydrocarbons from Water

Directory of Open Access Journals (Sweden)

Morgan Adams

2008-01-01

Full Text Available Hydrocarbons contamination of the marine environment generated by the offshore oil and gas industry is generated from a number of sources including oil contaminated drill cuttings and produced waters. The removal of hydrocarbons from both these sources is one of the most significant challenges facing this sector as it moves towards zero emissions. The application of a number of techniques which have been used to successfully destroy hydrocarbons in produced water and waste water effluents has previously been reported. This paper reports the application of semiconductor photocatalysis as a final polishing step for the removal of hydrocarbons from two waste effluent sources. Two reactor concepts were considered: a simple flat plate immobilised film unit, and a new rotating drum photocatalytic reactor. Both units proved to be effective in removing residual hydrocarbons from the effluent with the drum reactor reducing the hydrocarbon content by 90% under 10 minutes.

Bioremediation: Technology for treating hydrocarbon-contaminated wastewater

Energy Technology Data Exchange (ETDEWEB)

Towprayoon, S.; Kuntrangwattana, S. [King Mongkut`s Institute of Technology, Bangkok (Thailand)

1996-12-31

Cutting oil wastewater from an iron and steel factory was applied to the soil windrow. Self-remediation was then compared with remediation with acclimatized indigenous microbes. The incremental reduction rate of the microorganisms and hydrocarbon-degradable microbes was slower in self-remediation than in the latter treatment. Within 30 days, when the acclimatized indigenous microbes were used, there was a significant reduction of the contaminated hydrocarbons, while self-remediation took longer to reduce to the same concentration. Various nitrogen sources were applied to the soil pile, namely, organic compost, chemical fertilizer, ammonium sulfate, and urea. The organic compost induced a high yield of hydrocarbon-degradable microorganisms, but the rate at which the cutting oil in the soil decreased was slower than when other nitrogen sources were used. The results of cutting oil degradation studied by gas chromatography showed the absence of some important hydrocarbons. The increment of the hydrocarbon-degradable microbes in the land treatment ecosystem does not necessarily correspond to the hydrocarbon reduction efficiency. 3 refs., 3 figs.

Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment

International Nuclear Information System (INIS)

Mishra, Nitika; Ayoko, Godwin A.; Morawska, Lidia

2016-01-01

Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis – Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. - Highlights: • PAHs represent a major group of outdoor air pollutants. • Concentration levels of PAHS in urban schools ranged from 1.2 to 38 ng/m"3. • PCA–APCS technique used to identify sources of PAHs and their contributions. • Vehicular emissions (56%) were found to be the prominent sources of PAHs.

Improving Thin Bed Identification in Sarawak Basin Field using Short Time Fourier Transform Half Cepstrum (STFTHC) method

Science.gov (United States)

Nizarul, O.; Hermana, M.; Bashir, Y.; Ghosh, D. P.

2016-02-01

In delineating complex subsurface geological feature, broad band of frequencies are needed to unveil the often hidden features of hydrocarbon basin such as thin bedding. The ability to resolve thin geological horizon on seismic data is recognized to be a fundamental importance for hydrocarbon exploration, seismic interpretation and reserve prediction. For thin bedding, high frequency content is needed to enable tuning, which can be done by applying the band width extension technique. This paper shows an application of Short Time Fourier Transform Half Cepstrum (STFTHC) method, a frequency bandwidth expansion technique for non-stationary seismic signal in increasing the temporal resolution to uncover thin beds and improve characterization of the basin. A wedge model and synthetic seismic data is used to quantify the algorithm as well as real data from Sarawak basin were used to show the effectiveness of this method in enhancing the resolution.

Partitioning and source diagnostics of polycyclic aromatic hydrocarbons in rivers in Tianjin, China

International Nuclear Information System (INIS)

Shi, Z.; Tao, S.; Pan, B.; Liu, W.X.; Shen, W.R.

2007-01-01

Water, suspended particulate matter (SPM), and sediment samples were collected from ten rivers in Tianjin and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), dissolved organic carbon (DOC), particulate organic carbon (POC) in SPM and total organic carbon (TOC) in sediment. The behavior and fate of PAHs influenced by these parameters were examined. Generally, organic carbon was the primary factor controlling the behavior of the 16 PAH species. Partitioning of PAHs between SPM and water phase was studied, and K OC for some PAH species were found to be significantly higher than the predicted values. The source of PAHs contamination was diagnosed by using PAH isomer ratios. Coal combustion was identified to be a long-term and prevailing contamination source for sediment, while sewage/wastewater source could reasonably explain a short-term PAHs contamination of SPM. - Distribution of PAHs among water, suspended solids and sediment was under strong influence of naturally occurring organic carbon

Molecular isotopic characterisation of hydrocarbon biomarkers in Palaeocene-Eocene evaporitic, lacustrine source rocks from the Jianghan Basin, China

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Grice, Kliti; Schouten, S.; Peters, Kenneth E.

1998-01-01

Immature organic matter in lacustrine source rocks from the Jianghan Basin, eastern China, was studied for distributions and stable carbon isotopic compositions (13C) of hydrocarbon biomarkers. All of the bitumens contain isorenieratane (13C ca. −17 ) indicating the presence of Chlorobiaceae, and

Understanding Sediment Sources, Pathways, and Sinks in Regional Sediment Management: Application of Wash Load and Bed-Material Load Concept

National Research Council Canada - National Science Library

Biedenham, David S; Hubbard, Lisa C; Thome, Colin R; Watson, Chester C

2006-01-01

... through the fluvial system for sediments derived from various bed, bank, gully, and catchment sources thereby providing a reliable analytical foundation for effective regional sediment management...

Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall

International Nuclear Information System (INIS)

Zhang Wei; Zhang Shucai; Wan Chao; Yue Dapan; Ye Youbin; Wang Xuejun

2008-01-01

Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing. - Urban road runoff and road dust, canopy throughfall and rain were considered as a system for diagnostics of PAH sources

Petroleum systems and hydrocarbon accumulation models in the Santos Basin, SP, Brazil; Sistemas petroliferos e modelos de acumulacao de hidrocarbonetos na Bacia de Santos

Energy Technology Data Exchange (ETDEWEB)

Chang, Hung Kiang; Assine, Mario Luis; Correa, Fernando Santos; Tinen, Julio Setsuo [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Lab. de Estudos de Bacias]. E-mails: chang@rc.unesp.br; assine@rc.unesp.br; fscorrea@rc.unesp.br; jstinen@rc.unesp.br; Vidal, Alexandre Campane; Koike, Luzia [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro de Estudos de Petroleo]. E-mails: vidal@ige.unicamp.br; luzia@iqm.unicamp.br

2008-07-01

The Santos Basin was formed by rifting process during Mesozoic Afro-American separation. Sediment accumulation initiated with fluvial-lacustrine deposits, passing to evaporitic stage until reaching marginal basin stages. The analysis of hydrocarbon potential of Santos Basin identified two petroleum systems: Guaratiba-Guaruja and Itajai-Acu-Ilhabela. The Guaratiba Formation is less known in the Santos Basin because of small number of wells that have penetrated the rift section. By comparison with Campos Basin, hydrocarbons are of saline lacustrine origin deposited in Aptian age. Analogous to Campos Basin the major source rock is of saline-lacustrine origin, which has been confirmed from geochemical analyses of oil samples recovered from the various fields. These analyses also identified marine source rock contribution, indicating the Itajai-Acu source rock went through oil-window, particularly in structural lows generated by halokynesis. Models of hydrocarbon accumulation consider Guaratiba Formacao as the major source rock for shallow carbonate reservoirs of Guaruja Formacao and for late Albian to Miocene turbidites, as well as siliciclastic and carbonate reservoirs of the rift phase. Migration occurs along salt window and through carrier-beds. The seal rock is composed of shales and limestones intercalated with reservoir facies of the post-rift section and by thick evaporites overlying rift section, especially in the deeper water. In the shallow portion, shale inter-tongued with reservoir rocks is the main seal rock. The hydrocarbon generation and expulsion in the central-north portion of the basin is caused by overburden of a thick Senonian section. Traps can be structural (rollovers and turtle), stratigraphic (pinch-outs) and mixed origins (pinch-outs of turbidites against salt domes). (author)

The composition and the source of hydrocarbons in sediments taken from the tectonically active Andaman Backarc Basin, Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Chernova, T.G.; Rao, P.S.; Pikovskii, Yu.I.; Alekseeva, T.A.; Nath, B.N.; Rao, B.R.; Rao, Ch.M.

or hydrothermal organic matter. Anthropogenic sources in region studied are of minor importance. From the results obtained, it may be deduced that the hydrocarbons in the sediments of the tectonically active part of the Andaman Basin are mainly due...

Parsing pyrogenic polycyclic aromatic hydrocarbons: forensic chemistry, receptor models, and source control policy.

Science.gov (United States)

O'Reilly, Kirk T; Pietari, Jaana; Boehm, Paul D

2014-04-01

A realistic understanding of contaminant sources is required to set appropriate control policy. Forensic chemical methods can be powerful tools in source characterization and identification, but they require a multiple-lines-of-evidence approach. Atmospheric receptor models, such as the US Environmental Protection Agency (USEPA)'s chemical mass balance (CMB), are increasingly being used to evaluate sources of pyrogenic polycyclic aromatic hydrocarbons (PAHs) in sediments. This paper describes the assumptions underlying receptor models and discusses challenges in complying with these assumptions in practice. Given the variability within, and the similarity among, pyrogenic PAH source types, model outputs are sensitive to specific inputs, and parsing among some source types may not be possible. Although still useful for identifying potential sources, the technical specialist applying these methods must describe both the results and their inherent uncertainties in a way that is understandable to nontechnical policy makers. The authors present an example case study concerning an investigation of a class of parking-lot sealers as a significant source of PAHs in urban sediment. Principal component analysis is used to evaluate published CMB model inputs and outputs. Targeted analyses of 2 areas where bans have been implemented are included. The results do not support the claim that parking-lot sealers are a significant source of PAHs in urban sediments. © 2013 SETAC.

Hydrocarbon-degradation by Isolate Pseudomonas lundensis UTAR FPE2

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Adeline, S. Y. Ting

2009-01-01

Full Text Available In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

Removal of light petroleum hydrocarbons from water sources using polypropylene and titanium dioxide nano-composite

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H. Karyab

2016-08-01

Full Text Available Background: Petroleum hydrocarbons are the most important pollutants which threat human health and aquatics. Adsorbents are one of the common equipment in water pollution management; however, their applications have been associated with limitations. Objective: To evaluate the potential of polypropylene/titanium dioxide Nano-composite in adsorption of light petroleum hydrocarbons from water sources. Methods: This experimental study was conducted at school of health, Qazvin University of Medical Sciences in 2014-15. Activation of polypropylene fibers, with 1 cm length and 300 microns diameters, was achieved with wet heating. To synthesize of nano-composite the fibers were coated with nano-titanium dioxide with 20 nm diameter. The sonication was performed at 26 kHz and 100 W of power in 40ºc. The morphology of the fractured surfaces of impact specimens was examined by FESEM. The adsorption rate of petrol and gasoline, as surrogate of TPH, was evaluated in different retention time within polyamide mesh aperture diameter of 250 nm. Average of TPH adsorbing, per unit weight of adsorbent, were analyzed with analysis of variance and Scheffe post hoc tests. Findings: The FESEM micrographs showed that the dispersion of the nano-Tio2 particles was relatively good and only few aggregations exist. The maximum adsorption capacity of petrol and gasoline was obtained in 30 minute. The adsorption rate of gasoline was 6.49±0.10 g/g and oil was 7.01±0.13 g/g. Conclusion: According to the results and in comparison with commercial imported adsorbents, the synthesized Nano-composite had favorable performance. The results show that the polypropylene/Tio2 Nano-composite can be used effectively in light petroleum hydrocarbons removal from polluted water sources.

Diesel NO{sub x} reduction by plasma-regenerated absorbent beds

Science.gov (United States)

Wallman, P.H.; Vogtlin, G.E.

1998-02-10

Reduction of NO{sub x} from diesel engine exhaust by use of plasma-regenerated absorbent beds is described. This involves a process for the reduction of NO{sub x} and particulates from diesel engines by first absorbing NO{sub x} onto a solid absorbent bed that simultaneously acts as a physical trap for the particulate matter, and second regenerating said solid absorbent by pulsed plasma decomposition of absorbed NO{sub x} followed by air oxidation of trapped particulate matter. The absorbent bed may utilize all metal oxides, but the capacity and the kinetics of absorption and desorption vary between different materials, and thus the composition of the absorbent bed is preferably a material which enables the combination of NO{sub x} absorption capability with catalytic activity for oxidation of hydrocarbons. Thus, naturally occurring or synthetically prepared materials may be utilized, particularly those having NO{sub x} absorption properties up to temperatures around 400 C which is in the area of diesel engine exhaust temperatures. 1 fig.

Variations in the stable isotope ratios of specific aromatic and aliphatic hydrocarbons from coal conversion processes

Energy Technology Data Exchange (ETDEWEB)

McRae, C.; Snape, C.E.; Fallick, A.E. [University of Strathclyde, Glasgow (United Kingdom). Dept. of Pure and Applied Chemistry

1998-07-01

To establish the scope for applying gas chromatography-isotope ratio mass spectrometry ({sup {delta}-13}C GC-IRMS) to molecular recognition problems in coal utilisation, {sup 13}C/{sup 12}C isotope ratios were determined for n-alkanes and polycyclic aromatic hydrocarbons (PAHs) as a function of coal rank and process conditions. Six coals ranging from a lignite to a low volatile bituminous coal were subjected to chloroform extraction, fixed-bed pyrolysis under hydrogen pressure (hydropyrolysis) and fluidised-bed (flash) pyrolysis. No significant variations in the stable isotope ratios of n-alkanes were evident as a function of either rank or conversion regime. In contrast, the isotope ratios of PAHs show large variations with those for hydropyrolysis (-23 to -25 parts per thousand) being similar to the bulk values of the initial coals and being isotopically heavier (less negative) than their fluidised-bed pyrolysis counterparts by 2-3 parts per thousand. However, the PAHs from fluidised-bed pyrolysis, which resemble closely those obtained from high temperature coal carbonization, are still heavier (by 2-3 parts per thousand) than those from diesel particulates and coal gasification and combustion residues. This provides a firm basis for the source apportionment of airborne PAHs in the proximity of coking plants, particularly with no major variations in the PAH isotope ratios being found as a function of rank.

In-situ hydrocarbon delineation using laser-induced fluorescence

International Nuclear Information System (INIS)

Taer, A.D.; Hastings, R.W.; Brown, A.Y.; Frend, R.

1996-01-01

An investigation of hydrocarbons in soils was conducted at an active Shell Oil Company petroleum products terminal, located in Carson, California. An investigation approach involving Laser-Induced Fluorescence (LIF) and Cone Penetrometer Testing (CPT) technologies was implemented to provide real-time, in-situ characterization of site stratigraphy, hydrocarbon distribution and importantly, hydrocarbon product differentiation. The area of investigation is located along a property boundary, where a plume of separate phase hydrocarbons has been actively recovered for several years. CPT/LIF technology was selected for the investigation since previous delineation efforts using hydrocarbon fingerprinting methods proved inconclusive. Additionally, the CPT/LIF technology had the potential to provide a cost effective solution to accomplish project objectives. Based on the information obtained during this investigation, it was determined that the plume of separate phase hydrocarbons along the northern property boundary is from a source distinctly different than any identified hydrocarbons known to be from on-site sources. In addition, the plume was determined to not be connected with any other known on-site hydrocarbon plumes. The results of this CPT/LIF investigation were consistent with the known hydrogeologic conditions. This evaluation determined that CPT/LIF technology was very effective in addressing project objectives and resulted in a significant cost savings

Tolerance of Antarctic soil fungi to hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Hughes, Kevin A.; Bridge, Paul; Clark, Melody S. [British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET (United Kingdom)

2007-01-01

Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research Station (Adelaide Island, Antarctic Peninsula) was assessed in the presence of ten separate aromatic and aliphatic hydrocarbons [marine gas oil (MGO), dodecane, hexadecane, benzoic acid, p-hydroxybenzoic acid, toluene, phenol, biphenyl, naphthalene and m- and p-xylenes with ethylbenzene]. Aromatic hydrocarbons inhibited soil microbial growth more than aliphatic hydrocarbons. Soil microorganisms from a moss patch, where little previous impact or hydrocarbon contamination had occurred, were less tolerant of hydrocarbons than those from high impact sites. Fungal growth rates of Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp. and Phoma herbarum were assessed in the presence of hydrocarbons. Generally, aromatic hydrocarbons inhibited or stopped hyphal extension, though growth rates increased with some aliphatic hydrocarbons. Hyphal dry weight measurements suggested that Mortierella sp. may be able to use dodecane as sole carbon and energy source. Hydrocarbon-degrading Antarctic fungi may have use in future hydrocarbon spill bioremediation. (author)

Direct electroreduction of CO2 into hydrocarbon

International Nuclear Information System (INIS)

Winea, Gauthier; Ledoux, Marc-Jacques; Pham-Huu, Cuong; Gangeri, Miriam; Perathoner, Siglinda; Centi, Gabriele

2006-01-01

A lot of methods exist to directly reduce carbon dioxide into hydrocarbons: the photoelectrochemical process is certainly the most interesting, essentially due to the similarities with photosynthesis. As the human activities produce a great quantity of CO 2 , this one can then be considered as an infinite source of carbon. The products of this reaction are identical to those obtained during a Fischer-Tropsch reaction, that is to say hydrocarbons, alcohols and carboxylic acids. These works deal with the electrochemical reduction of CO 2 in standard conditions of temperature and pressure. The photochemical part has been replaced by a current generator as electrons source and a KHCO 3 aqueous solution as protons source. The first catalytic results clearly show that it is possible to reduce CO 2 into light hydrocarbons, typically from C1 to C9. (O.M.)

Geochemical assessment of light gaseous hydrocarbons in near-surface soils of Kutch-Saurashtra: Implication for hydrocarbon prospects

Science.gov (United States)

Rao, P. Lakshmi Srinivasa; Madhavi, T.; Srinu, D.; Kalpana, M. S.; Patil, D. J.; Dayal, A. M.

2013-02-01

Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil gases, methane and heavier homologues were recorded in the near-surface soil samples collected from Kutch-Saurashtra, India. Soil gas alkanes were interpreted to be derived from deep-seated hydrocarbon sources and have migrated to the surface through structural discontinuities. The source of hydrocarbons is assessed to be thermogenic and could have been primarily derived from humic organic matter with partial contribution from sapropelic matter. Gas chromatographic analyses of hydrocarbons desorbed from soil samples through acid extraction technique showed the presence of methane through n-butane and the observed concentrations (in ppb) vary from: methane (C1) from 4-291, ethane (C2) from 0-84, propane (C3) from 0-37, i-butane (iC4) from 0-5 and n-butane (nC4) from 0-4. Carbon isotopes measured for methane and ethane by GC-C-IRMS, range between -42.9‰ to -13.3‰ (Pee Dee Belemnite - PDB) and -21.2‰ to -12.4‰ (PDB), respectively. The increased occurrence of hydrocarbons in the areas near Anjar of Kutch and the area south to Rajkot of Saurashtra signifies the area potential for oil and gas.

A review on polycyclic aromatic hydrocarbons: Source, environmental impact, effect on human health and

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Hussein I. Abdel-Shafy

2016-03-01

The aim of this review is to discuss PAHs impact on the environmental and the magnitude of the human health risks posed by such substances. They also contain important information on concentrations, burdens and fate of polycyclic aromatic hydrocarbons (PAHs in the atmosphere. The main anthropogenic sources of PAHs and their effect on the concentrations of these compounds in air are discussed. The fate of PAHs in the air, their persistence and the main mechanisms of their losses are presented. Health hazards associated with PAH air pollution are stressed.

Hydrocarbon Potential in Sandstone Reservoir Isolated inside Low Permeability Shale Rock (Case Study: Beruk Field, Central Sumatra Basin)

Science.gov (United States)

Diria, Shidqi A.; Musu, Junita T.; Hasan, Meutia F.; Permono, Widyo; Anwari, Jakson; Purba, Humbang; Rahmi, Shafa; Sadjati, Ory; Sopandi, Iyep; Ruzi, Fadli

2018-03-01

Upper Red Bed, Menggala Formation, Bangko Formation, Bekasap Formation and Duri Formationare considered as the major reservoirs in Central Sumatra Basin (CSB). However, Telisa Formation which is well-known as seal within CSB also has potential as reservoir rock. Field study discovered that lenses and layers which has low to high permeability sandstone enclosed inside low permeability shale of Telisa Formation. This matter is very distinctive and giving a new perspective and information related to the invention of hydrocarbon potential in reservoir sandstone that isolated inside low permeability shale. This study has been conducted by integrating seismic data, well logs, and petrophysical data throughly. Facies and static model are constructed to estimate hydrocarbon potential resource. Facies model shows that Telisa Formation was deposited in deltaic system while the potential reservoir was deposited in distributary mouth bar sandstone but would be discontinued bedding among shale mud-flat. Besides, well log data shows crossover between RHOB and NPHI, indicated that distributary mouth bar sandstone is potentially saturated by hydrocarbon. Target area has permeability ranging from 0.01-1000 mD, whereas porosity varies from 1-30% and water saturation varies from 30-70%. The hydrocarbon resource calculation approximates 36.723 MSTB.

Polycyclic Aromatic Hydrocarbons in the Dagang Oilfield (China: Distribution, Sources, and Risk Assessment

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Haihua Jiao

2015-05-01

Full Text Available The levels of 16 polycyclic aromatic hydrocarbons (PAHs were investigated in 27 upper layer (0–25 cm soil samples collected from the Dagang Oilfield (China in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs varied between 103.6 µg·kg−1 and 5872 µg·kg−1, with a mean concentration of 919.8 µg·kg−1; increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg−1, to oil well areas (mean of 627.3 µg·kg−1, to urban and residential zones (mean of 1856 µg·kg−1. Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B or not classified/non-carcinogenic (NB. The total concentrations of carcinogenic PAHs (∑BPAHs varied from 13.3 µg·kg−1 to 4397 µg·kg−1 across all samples, with a mean concentration of 594.4 µg·kg−1. The results suggest that oilfield soil is subject to a certain level of ecological environment risk.

Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)

Science.gov (United States)

Kosakowski, Paweł; Wróbel, Magdalena

2012-08-01

Burial history, thermal maturity, and timing of hydrocarbon generation were modelled for the Jurassic source rocks in the basement of the Carpathian Foredeep and marginal part of the Outer Carpathians. The area of investigation was bounded to the west by Kraków, to the east by Rzeszów. The modelling was carried out in profiles of wells: Będzienica 2, Dębica 10K, Góra Ropczycka 1K, Goleszów 5, Nawsie 1, Pławowice E1 and Pilzno 40. The organic matter, containing gas-prone Type III kerogen with an admixture of Type II kerogen, is immature or at most, early mature to 0.7 % in the vitrinite reflectance scale. The highest thermal maturity is recorded in the south-eastern part of the study area, where the Jurassic strata are buried deeper. The thermal modelling showed that the obtained organic matter maturity in the initial phase of the "oil window" is connected with the stage of the Carpathian overthrusting. The numerical modelling indicated that the onset of hydrocarbon generation from the Middle Jurassic source rocks was also connected with the Carpathian thrust belt. The peak of hydrocarbon generation took place in the orogenic stage of the overthrusting. The amount of generated hydrocarbons is generally small, which is a consequence of the low maturity and low transformation degree of kerogen. The generated hydrocarbons were not expelled from their source rock. An analysis of maturity distribution and transformation degree of the Jurassic organic matter shows that the best conditions for hydrocarbon generation occurred most probably in areas deeply buried under the Outer Carpathians. It is most probable that the "generation kitchen" should be searched for there.

Factors controlling leaching of polycyclic aromatic hydrocarbons from petroleum source rock using nonionic surfactant

Energy Technology Data Exchange (ETDEWEB)

Akinlua, Akinsehinwa [Obafemi Awolowo Univ., Ile-Ife (Nigeria). Fossil Fuels and Environmental Geochemistry Group; Jochmann, Maik A.; Qian, Yuan; Schmidt, Torsten C. [Duisburg-Essen Univ., Essen (Germany). Instrumental Analytical Chemistry; Sulkowski, Martin [Duisburg-Essen Univ., Essen (Germany). Inst. of Environmental Analytical Chemistry

2012-03-15

The extraction of polycyclic aromatic hydrocarbons (PAHs) from petroleum source rock by nonionic surfactants with the assistance of microwave irradiation was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and type of surfactant have significant effects on extraction yields of PAHs. Factors such as surfactant concentration, irradiation power, sample/solvent ratio and mixing surfactants (i.e., mixture of surfactant at specific ratio) also influence the extraction efficiencies for these compounds. The optimum temperature for microwave-assisted nonionic surfactant extraction of PAHs from petroleum source rock was 120 C and the best suited surfactant was Brij 35. The new method showed extraction efficiencies comparable to those afforded by the Soxhlet extraction method, but a reduction of the extraction times and environmentally friendliness of the new nonionic surfactant extraction system are clear advantages. The results also show that microwave-assisted nonionic surfactant extraction is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock. (orig.)

Problems in the fingerprints based polycyclic aromatic hydrocarbons source apportionment analysis and a practical solution

International Nuclear Information System (INIS)

Zou, Yonghong; Wang, Lixia; Christensen, Erik R.

2015-01-01

This work intended to explain the challenges of the fingerprints based source apportionment method for polycyclic aromatic hydrocarbons (PAH) in the aquatic environment, and to illustrate a practical and robust solution. The PAH data detected in the sediment cores from the Illinois River provide the basis of this study. Principal component analysis (PCA) separates PAH compounds into two groups reflecting their possible airborne transport patterns; but it is not able to suggest specific sources. Not all positive matrix factorization (PMF) determined sources are distinguishable due to the variability of source fingerprints. However, they constitute useful suggestions for inputs for a Bayesian chemical mass balance (CMB) analysis. The Bayesian CMB analysis takes into account the measurement errors as well as the variations of source fingerprints, and provides a credible source apportionment. Major PAH sources for Illinois River sediments are traffic (35%), coke oven (24%), coal combustion (18%), and wood combustion (14%). - Highlights: • Fingerprint variability poses challenges in PAH source apportionment analysis. • PCA can be used to group compounds or cluster measurements. • PMF requires results validation but is useful for source suggestion. • Bayesian CMB provide practical and credible solution. - A Bayesian CMB model combined with PMF is a practical and credible fingerprints based PAH source apportionment method

The role of fluid migration system in hydrocarbon accumulation in Maichen Sag, Beibuwan Basin

Science.gov (United States)

Liu, Hongyu; Yang, Jinxiu; Wu, Feng; Chen, Wei; Liu, Qianqian

2018-02-01

Fluid migration system is of great significance for hydrocarbon accumulation, including the primary migration and secondary migration. In this paper, the fluid migration system is analysed in Maichen Sag using seismic, well logging and core data. Results show that many factors control the hydrocarbon migration process, including hydrocarbon generation and expulsion period from source rocks, microfractures developed in the source rocks, the connected permeable sand bodies, the vertical faults cutting into/through the source rocks and related fault activity period. The spatial and temporal combination of these factors formed an effective network for hydrocarbon expulsion and accumulation, leading to the hydrocarbon reservoir distribution at present. Generally, a better understanding of the hydrocarbon migration system can explain the present status of hydrocarbon distribution, and help select future target zones for oil and gas exploration.

Patterns and sources of particle-phase aliphatic and polycyclic aromatic hydrocarbons in urban and rural sites of western Greece

Science.gov (United States)

Kalaitzoglou, Maria; Terzi, Eleni; Samara, Constantini

Particle-bound aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs, respectively) were determined in the ambient air of the Eordea basin, in western Greece, where intensive coal burning for power generation takes place. Thirteen PAHs, n-alkanes (C 14-C 35), hopanes, and isoprenoid hydrocarbons (pristane and phytane) were determined in the total suspended particles collected from the atmosphere of four sites within the basin receiving potential impacts from various sources, such as fly ash, coal mining, automobile traffic, domestic heating, and agricultural or refuse burning. The same organic species were also determined in the fly ash generated in power stations, and in particulate emissions from open burning of biomass (dry corn leaves) and refuse burning. Organic particle sources were resolved using concentration diagnostic ratios and factor analysis (FA). A multivariate statistical receptor model (Absolute Principal Component Analysis, APCA) was finally employed to estimate the contribution of identified sources to the measured concentrations of organic pollutants. Four major sources for ambient PAHs and AHs were identified displaying variable contribution in different sites: (a) fossil fuel combustion, (b) biogenic emissions, (c) refuse burning, and (d) oil residues. Fuel combustion was the major source of ambient PAHs and an important source of n-alkanes in the range C 21-C 28. Oil residues were found to be the major source of low molecular weight n-alkanes (particularly the C 14-C 16), and an important source of pristane, phytane and UCM. Biogenic sources were primarily responsible for the high molecular weight n-alkanes explaining almost the entire concentration levels of homologues >C 32. Biomass burning was particularly important for the C 23-C 26n-alkanes. Despite the vicinity of certain sampling sites to power stations, coal fly ash was not identifiable as a source for ambient PAHs and AHs.

Biological fluidized-bed treatment of groundwater from a manufactured gas plant site

International Nuclear Information System (INIS)

Grey, G.M.; Scheible, O.K.; Maiello, J.A.; Guarini, W.J.; Sutton, P.M.

1995-01-01

Bench- and pilot-scale biological treatability studies were performed as part of a comprehensive study for developing an on-site treatment system for contaminated groundwater at a former manufactured gas plant site. The bench-scale work, which included evaluations of activated sludge and fluidized-bed biological processes, indicated that a carbon-based fluidized-bed process was most appropriate. The process was then demonstrated on a pilot level at the site. The bench and pilot studies demonstrated significant reductions of chemical oxygen demand (COD), and all target organics including polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs)

Trace element characterisation of Cretaceous Orange Basin hydrocarbon source rocks

International Nuclear Information System (INIS)

Akinlua, A.; Adekola, S.A.; Swakamisa, O.; Fadipe, O.A.; Akinyemi, S.A.

2010-01-01

Research highlights: → Vanadium and nickel contents indicate that the rock samples from the Orange Basin have marine organic matter input. → The organic matter of the Orange Basin source rocks were deposited in reducing conditions. → Despite the similarities in the organic matter source input and depositional environment of the samples from the two well, cross plots of Co/Ni versus V/Ni and Mo/Ni versus Co/Ni were able to reveal their subtle differences. → Cluster analysis classified the samples into three groups based on subtle differences in their .thermal maturity. - Abstract: Trace elements in the kerogen fraction of hydrocarbon source rock samples from two wells obtained from the Cretaceous units of the Orange Basin, South Africa were determined using X-ray fluorescence spectrometry, in order to determine their distribution and geochemical significances. The concentrations of the elements (As, Ce, Co, Cu, Fe, Mo, Ni, Pb and V) determined ranged from 0.64 to 47,300 ppm for the samples analysed. The total organic carbon (TOC) values indicate that the samples are organic rich but did not show any trend with the distribution of the trace metals except Ce, Mo and Pb. Dendrogram cluster analysis discriminated the samples into three groups on the basis of their level of thermal maturity. Thermal maturity has a significant effect on the distribution of the trace metals. Cobalt/Ni and V/Ni ratios and cross plots of the absolute values of V and Ni indicate that the samples had significant marine organic matter input. The V and Ni contents and V/(V + Ni) ratio indicate that the organic matter of the source rocks had been deposited in reducing conditions. Despite the similarities in the organic matter source input and depositional environment of the organic matter of the samples from the two well, cross plots of Co/Ni versus V/Ni and Mo/Ni versus Co/Ni were able to reveal subtle differences. Cluster analysis of the samples was also able to reveal the subtle

Polycyclic aromatic hydrocarbons in coastal sediment of klang strait, Malaysia: distribution pattern, risk assessment and sources.

Science.gov (United States)

Tavakoly Sany, Seyedeh Belin; Hashim, Rosli; Salleh, Aishah; Rezayi, Majid; Mehdinia, Ali; Safari, Omid

2014-01-01

Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.

Polycyclic aromatic hydrocarbons in coastal sediment of klang strait, Malaysia: distribution pattern, risk assessment and sources.

Directory of Open Access Journals (Sweden)

Seyedeh Belin Tavakoly Sany

Full Text Available Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia. The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions, with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.

Polycyclic Aromatic Hydrocarbons in Coastal Sediment of Klang Strait, Malaysia: Distribution Pattern, Risk Assessment and Sources

Science.gov (United States)

Tavakoly Sany, Seyedeh Belin; Hashim, Rosli; Salleh, Aishah; Rezayi, Majid; Mehdinia, Ali; Safari, Omid

2014-01-01

Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait. PMID:24747349

Nitrocarburising in ammonia-hydrocarbon gas mixtures

DEFF Research Database (Denmark)

Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

2010-01-01

The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

Hydrocarbon source apportionment for the 1996 Paso del Norte Ozone Study

Energy Technology Data Exchange (ETDEWEB)

Fujita, E.M. [Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89506-0220 (United States)

2001-08-10

The 1996 Paso del Norte (PdN) ozone study was conducted to improve current understanding of the significant meteorological and air quality processes that lead to high concentrations of ozone in El Paso, Texas (USA) and Ciudad Juarez, Chihuahua (Mexico). Two-hour canister samples were collected five times daily at 05.00-07.00 h, 07.00-09.00 h, 09.00-11.00 h, 11.00-13.00 h, and 15.00-17.00 h MST during intensive study periods at one urban and one rural site on each side of the border. An automated gas chromatograph was operated at one site in central El Paso. Source profiles (the fractional chemical composition of emissions) from motor vehicles, gasoline, liquefied petroleum gas, and commercial natural gas were combined with source profiles from other studies for input to the Chemical Mass Balance (CMB) receptor model to apportion the measured non-methane hydrocarbons (NMHC) to sources. On-road vehicle emissions accounted for one-half to two-thirds of the NMHC in Ciudad Juarez and El Paso with the highest contributions occurring during the morning and afternoon commute periods. Emissions from diesel exhaust contributed approximately 2-3% of NMHC in Ciudad Juarez and less than 2% in El Paso. The average sum of liquid gasoline and gasoline vapor increased during the day in Ciudad Juarez from 2% at 06.00 h to approximately 12% at 16.00 h. Diurnal and day-of-the-week patterns in the liquid gasoline contributions are essentially identical to the corresponding patterns for motor vehicle exhaust, which suggest that a large fraction of the liquid gasoline contribution may be associated with tailpipe emissions rather than evaporative emissions from motor vehicles or industrial sources. Including the sum of the two sources put the upper limit for tailpipe contributions at 60-70% of NMHC.

Nitrocarburizing in ammonia-hydrocarbon gas mixtures

DEFF Research Database (Denmark)

Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

2011-01-01

The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

The effect of fuel and chlorinated hydrocarbons on a vapor phase carbon adsorption system

International Nuclear Information System (INIS)

Crawford, W.J.; Cheney, J.L.; Taggart, D.B.

1995-01-01

A soil vapor extraction (SVE) system installed at the South Tacoma Well 12A Superfund Site was designed to recover 1,2-dichloroethylene (DCE), trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,2,2-tetrachloroethane (1,1,2,2-TCA) from the vadose zone. The basic system consisted of twenty-two extraction wells, three centrifugal blowers, and three carbon adsorbers. The carbon adsorbers were regenerated on site by steam stripping. The mixture of steam and stripped organics was condensed and then decanted to separate the water from the organic phase. The recovered water was air stripped to remove the dissolved organics prior to discharge to the city storm sewer. The recovered organic phase was then shipped off site for thermal destruction. Previous reports described operating difficulties with the decanter, and air strippers. Sampling and analyses were performed which identified the problem as the simultaneous recovery of unexpected fuel hydrocarbons in addition to the solvents. Recovery of fuels resulted in a light phase in the decanter in addition to the water and heavy solvent phases. This required redesign of the decanter to handle the third phase. The effectiveness of desorption of the carbon beds by steam stripping gradually decreased as the remediation progressed into the second year of operation. Samples were collected from the carbon beds to evaluate the effect of the fuel and chlorinated hydrocarbons on the activated carbon. This report describes the results of these analyses. The data indicated that both 1,1,2,2-TCA and fuel hydrocarbons in the C-9 to C-24 range remained in the carbon beds after steam regeneration in sufficient quantities to require replacing the carbon

Optrode for sensing hydrocarbons

Science.gov (United States)

Miller, H.; Milanovich, F.P.; Hirschfeld, T.B.; Miller, F.S.

1988-09-13

A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons. 5 figs.

Distinguishing natural hydrocarbons from anthropogenic contamination in ground water

International Nuclear Information System (INIS)

Lesage, S.; Xu, H.; Novakowski, K.S.

1997-01-01

Differentiation between natural and anthropogenic sources of ground-water contamination by petroleum hydrocarbons is necessary in areas where natural hydrocarbons may be present in the subsurface. Because of the similarity in composition between natural and refined petroleum, the use of statistical techniques to discern trends is required. In this study, both multivariate plotting techniques and principal component analysis were used to investigate the origin of hydrocarbons from a variety of study sites. Ground-water and gas samples were collected from the Niagara Falls area and from three gasoline stations where leaking underground storage tanks had been found. Although soil gas surveys are used to indicate the presence of hydrocarbons, they were not useful in differentiating between natural and anthropogenic sources of contamination in ground water. Propane and pentene were found to be the most useful chemical parameters in discriminating between the natural and anthropogenic sources. These chemicals are not usually measured in investigations of ground-water contamination, yet analysis can be conducted by most environmental laboratories using conventional methods

Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China

Science.gov (United States)

Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan

2017-12-01

The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

Sources and Deposition of Polycyclic Aromatic Hydrocarbons to Western U.S. National Parks

Science.gov (United States)

USENKO, SASCHA; MASSEY SIMONICH, STACI L.; HAGEMAN, KIMBERLY J.; SCHRLAU, JILL E.; GEISER, LINDA; CAMPBELL, DON H.; APPLEBY, PETER G.; LANDERS, DIXON H.

2010-01-01

Seasonal snowpack, lichens, and lake sediment cores were collected from fourteen lake catchments in eight western U.S. National Parks and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) in order to determine their current and historical deposition, as well as to identify their potential sources. Seasonal snowpack was measured to determine the current wintertime atmospheric PAH deposition; lichens were measured to determine the long-term, year around deposition; and the temporal PAH deposition trends were reconstructed using lake sediment cores dated using 210Pb and 137Cs. The fourteen remote lake catchments ranged from low-latitude catchments (36.6° N) at high elevation (2900 masl) in Sequoia National Park, CA to high-latitude catchments (68.4° N) at low elevation (427 masl) in the Alaskan Arctic. Over 75% of the catchments demonstrated statistically significant temporal trends in ΣPAH sediment flux, depending on catchment proximity to source regions and topographic barriers. The ΣPAH concentrations and fluxes in seasonal snowpack, lichens, and surficial sediment were 3.6 to 60,000 times greater in the Snyder Lake catchment of Glacier National Park than the other 13 lake catchments. The PAH ratios measured in snow, lichen, and sediment were used to identify a local aluminum smelter as a major source of PAHs to the Snyder Lake catchment. These results suggest that topographic barriers influence the atmospheric transport and deposition of PAHs in high-elevation ecosystems and that PAH sources to these national park ecosystems range from local point sources to diffuse regional and global sources. PMID:20465303

A principal-component and least-squares method for allocating polycyclic aromatic hydrocarbons in sediment to multiple sources

International Nuclear Information System (INIS)

Burns, W.A.; Mankiewicz, P.J.; Bence, A.E.; Page, D.S.; Parker, K.R.

1997-01-01

A method was developed to allocate polycyclic aromatic hydrocarbons (PAHs) in sediment samples to the PAH sources from which they came. The method uses principal-component analysis to identify possible sources and a least-squares model to find the source mix that gives the best fit of 36 PAH analytes in each sample. The method identified 18 possible PAH sources in a large set of field data collected in Prince William Sound, Alaska, USA, after the 1989 Exxon Valdez oil spill, including diesel oil, diesel soot, spilled crude oil in various weathering states, natural background, creosote, and combustion products from human activities and forest fires. Spill oil was generally found to be a small increment of the natural background in subtidal sediments, whereas combustion products were often the predominant sources for subtidal PAHs near sites of past or present human activity. The method appears to be applicable to other situations, including other spills

Application of CaO-Based Bed Material for Dual Fluidized Bed Steam Biomass Gasification

Science.gov (United States)

Koppatz, S.; Pfeifer, C.; Kreuzeder, A.; Soukup, G.; Hofbauer, H.

Gasification of biomass is a suitable option for decentralized energy supply based on renewable sources in the range of up to 50 MW fuel input. The paper presents the dual fluidized bed (DFB) steam gasification process, which is applied to generate high quality and nitrogen-free product gas. Essential part of the DFB process is the bed material used in the fluidized reactors, which has significant impact on the product gas quality. By the use of catalytically active bed materials the performance of the overall process is increased, since the bed material favors reactions of the steam gasification. In particular, tar reforming reactions are favored. Within the paper, the pilot plant based on the DFB process with 100kW fuel input at Vienna University of Technology, Austria is presented. Actual investigations with focus on CaO-based bed materials (limestone) as well as with natural olivine as bed material were carried out at the pilot plant. The application of CaO-based bed material shows mainly decreased tar content in the product gas in contrast to experiments with olivine as bed material. The paper presents the results of steam gasification experiments with limestone and olivine, whereby the product gas composition as well as the tar content and the tar composition are outlined.

High atmosphere–ocean exchange of semivolatile aromatic hydrocarbons

KAUST Repository

González-Gaya, Belén

2016-05-16

Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 10 2 -10 3 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr -1, around 15% of the oceanic CO2 uptake. © 2016 Macmillan Publishers Limited.

Waste Plastic Converting into Hydrocarbon Fuel Materials

Energy Technology Data Exchange (ETDEWEB)

Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

2010-09-15

The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

A suggestion to assess spilled hydrocarbons as a greenhouse gas source

Energy Technology Data Exchange (ETDEWEB)

McAlexander, Benjamin L., E-mail: bmcalexander@trihydro.com

2014-11-15

Petroleum-contaminated site management typically counts destruction of hydrocarbons by either natural or engineered processes as a beneficial component of remediation. While such oxidation of spilled hydrocarbons is often necessary for achieving risk reduction for nearby human and ecological receptors, site assessments tend to neglect that this also means that the pollutants are converted to greenhouse gases and emitted to the atmosphere. This article presents a suggestion that the current and long term greenhouse gas emissions from spilled hydrocarbons be incorporated to petroleum site assessments. This would provide a more complete picture of pollutant effects that could then be incorporated to remedial objectives. At some sites, this additional information may affect remedy selection. Possible examples include a shift in emphasis to remedial technologies that reduce pollutant greenhouse gas effects (e.g., by conversion of methane to carbon dioxide in the subsurface), and a more holistic context for considering remedial technologies with low emission footprints.

Distribution and origin sources of Polycyclic Aromatic Hydrocarbons (PAHs) pollution in sediment of Sarawak coastal area

International Nuclear Information System (INIS)

Mohd Shuhaimi Elias; Abdul Khalik Wood; Zaleha Hashim; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Nazaratul Ashifa Abdullah Salim

2010-01-01

Alkyl and parent Polycyclic Aromatic Hydrocarbons (PAHs) compounds in marine sediment sample collected from ten locations along Sarawak coastal areas were extracted and analyzed by using gas chromatography-mass spectrometry. The source identification of PAH pollution in marine sediment of Sarawak coastal areas were identify by ratios technique of An/ An+phen, Fl/ Fl +Py, B[a]A/ (B[a]A+Chry) and total Methyl Phen/ Phen. The total alkyl and parent PAHs concentration varies from 36.5 - 277.4 ng/ g dry weight (d.w.) with a mean concentration of 138.2 ng/ g d.w. The ratio values of PAHs pollution in marine sediment of Sarawak coastal areas are clearly indicating the PAHs pollutions are originated from petroleum (petrogenic) and petroleum combustion (pyrolytic). However, the origin sources of PAHs pollution in a few stations were uncertain due to mixing sources of PAHs. (author)

Screening of biosurfactant producers from petroleum hydrocarbon contaminated sources in cold marine environments.

Science.gov (United States)

Cai, Qinhong; Zhang, Baiyu; Chen, Bing; Zhu, Zhiwen; Lin, Weiyun; Cao, Tong

2014-09-15

An overview of literature about isolating biosurfactant producers from marine sources indicated no such producers have been reported form North Atlantic Canada. Water and sediment samples were taken from petroleum hydrocarbon contaminated coastal and offshore areas in this region. Either n-hexadecane or diesel was used as the sole carbon source for the screening. A modified colony-based oil drop collapsing test was used to cover sessile biosurfactant producers. Fifty-five biosurfactant producers belong to genera of Alcanivorax, Exiguobacterium, Halomonas, Rhodococcus, Bacillus, Acinetobacter, Pseudomonas, and Streptomyces were isolated. The first three genera were established after 1980s with interesting characteristics and limited relevant publications. Some of the 55 isolated strains were found with properties such as greatly reducing surface tension, stabilizing emulsion and producing flocculant. Isolates P6-4P and P1-5P were selected to demonstrate the performance of biosurfactant production, and were found to reduce the surface tension of water to as low as 28 dynes/cm. Copyright © 2014 Elsevier Ltd. All rights reserved.

Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

Science.gov (United States)

2014-01-01

Background Coastal sediments in the northern Gulf of Mexico have a high potential of being contaminated by petroleum hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), due to extensive petroleum exploration and transportation activities. In this study we evaluated the spatial distribution and contamination sources of PAHs, as well as the bioavailable fraction in the bulk PAH pool, in surface marsh and shelf sediments (top 5 cm) of the northern Gulf of Mexico. Results PAH concentrations in this region ranged from 100 to 856 ng g−1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the lowest concentrations in shelf sediments. The PAH concentrations correlated positively with atomic C/N ratios of sedimentary organic matter (OM), suggesting that terrestrial OM preferentially sorbs PAHs relative to marine OM. PAHs with 2 rings were more abundant than those with 5–6 rings in continental shelf sediments, while the opposite was found in marsh sediments. This distribution pattern suggests different contamination sources between shelf and marsh sediments. Based on diagnostic ratios of PAH isomers and principal component analysis, shelf sediment PAHs were petrogenic and those from marsh sediments were pyrogenic. The proportions of bioavailable PAHs in total PAHs were low, ranging from 0.02% to 0.06%, with higher fractions found in marsh than shelf sediments. Conclusion PAH distribution and composition differences between marsh and shelf sediments were influenced by grain size, contamination sources, and the types of organic matter associated with PAHs. Concentrations of PAHs in the study area were below effects low-range, suggesting a low risk to organisms and limited transfer of PAHs into food web. From the source analysis, PAHs in shelf sediments mainly originated from direct petroleum contamination, while those in marsh sediments were from combustion of fossil fuels. PMID:24641695

Coupling of separation and reaction in zeolite membrane reactor for hydroisomerization of hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Gora, L.; Jansen, J.C. [Ceramic Membrane Centre, The Pore, DelftChemTech, Delft Univ. of Technology, Delft (Netherlands)

2005-03-01

A zeolite membrane reactor has been developed for the hydroisomerization of hydrocarbons, in which the linear molecules are separated from branched ones on the silicalite-1 membrane prior to conversion of the permeated linear hydrocarbons to equilibrium levels on the catalyst bed. Model studies using C{sub 6} components are conducted. n-C{sub 6} separated from 2MP (selectivity 24) is converted for 72% with 36% selectivity towards di-branched isomers (at 393 K). The results indicate that platinum containing chlorinated alumina/silicalite-1 membrane reactor has a potential in upgrading octane values and offers advantages such as higher efficiency, better process control and lower consumption of energy. (orig.)

Coupling of separation and reaction in zeolite membrane reactor for hydroisomerization of hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Gora, L.; Maloncy, M.L.; Jansen, J.C. [Ceramic Membrane Centre, The Pore, DelftChemTech, Delft Univ. of Technology (Netherlands)

2004-07-01

A zeolite membrane reactor has been developed for the hydroisomerization of hydrocarbons, in which the linear molecules are separated from branch ones on the silicalite-1 membrane prior to conversion of the permeated linear hydrocarbons to equilibrium levels on the catalyst bed. A model studies using C6 components are conduct. Separated n-C6 from 2MP (selectivity 24) is converted for 72% with 36% selectivity towards di-branched isomers (at 393 K). The results indicate that platinum containing chlorinated alumina/silicalite-1 membrane reactor has a potential in upgrading octane values and offers advantages such as higher efficiency, better process control and lower consumption of energy. (orig.)

Uranium bed oxidation vacuum process system

International Nuclear Information System (INIS)

McLeland, H.L.

1977-01-01

Deuterium and tritium gases are occluded in uranium powder for release into neutron generator tubes. The uranium powder is contained in stainless steel bottles, termed ''beds.'' If these beds become damaged, the gases must be removed and the uranium oxidized in order not to be flammable before shipment to ERDA disposal grounds. This paper describes the system and methods designed for the controlled degassing and oxidation process. The system utilizes sputter-ion, cryo-sorption and bellows pumps for removing the gases from the heated source bed. Removing the tritium gas is complicated by the shielding effect of helium-3, a byproduct of tritium decay. This effect is minimized by incremental pressure changes, or ''batch'' processing. To prevent runaway exothermic reaction, oxidation of the uranium bed is also done incrementally, or by ''batch'' processing, rather than by continuous flow. The paper discusses in detail the helium-3 shielding effect, leak checks that must be made during processing, bed oxidation, degree of gas depletion, purity of gases sorbed from beds, radioactivity of beds, bed disposal and system renovation

Distribution, Source, and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Sediment of Liaodong Bay, Northeast China

Science.gov (United States)

Xu, Shuang; Tao, Ping; Li, Yuxia; Guo, Qi; Zhang, Yan; Wang, Man; Jia, Hongliang; Shao, Mihua

2018-01-01

Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from Liaodong Bay, northeast China. The concentration levels of total PAHs (Σ16PAHs) in sediment were 11.0˜249.6 ng·g-1 dry weight (dw), with a mean value of 89.9 ng·g-1 dry weight (dw). From the point of the spatial distribution, high PAHs levels were found in the western areas of Liaodong Bay. In the paper, sources of PAHs were investigated by diagnostic ratios, which indicated that pyrogenic sources were the main sources of PAHs in the sediment of Liaodong Bay. Therefore, selected PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL indexes) for evaluation probable toxic effects on marine organism.

Hydrocarbon source apportionment for the 1996 Paso del Norte Ozone Study.

Science.gov (United States)

Fujita, E M

2001-08-10

The 1996 Paso del Norte (PdN) ozone study was conducted to improve current understanding of the significant meteorological and air quality processes that lead to high concentrations of ozone in El Paso, Texas (USA) and Ciudad Juárez, Chihuahua (Mexico). Two-hour canister samples were collected five times daily at 05.00-07.00 h, 07.00-09.00 h, 09.00-11.00 h, 11.00-13.00 h, and 15.00-17.00 h MST during intensive study periods at one urban and one rural site on each side of the border. An automated gas chromatograph was operated at one site in central El Paso. Source profiles (the fractional chemical composition of emissions) from motor vehicles, gasoline, liquefied petroleum gas, and commercial natural gas were combined with source profiles from other studies for input to the Chemical Mass Balance (CMB) receptor model to apportion the measured non-methane hydrocarbons (NMHC) to sources. On-road vehicle emissions accounted for one-half to two-thirds of the NMHC in Ciudad Juárez and El Paso with the highest contributions occurring during the morning and afternoon commute periods. Emissions from diesel exhaust contributed approximately 2-3% of NMHC in Ciudad Juárez and less than 2% in El Paso. The average sum of liquid gasoline and gasoline vapor increased during the day in Ciudad Juárez from 2% at 06.00 h to approximately 12% at 16.00 h. Diurnal and day-of-the-week patterns in the liquid gasoline contributions are essentially identical to the corresponding patterns for motor vehicle exhaust, which suggest that a large fraction of the liquid gasoline contribution may be associated with tailpipe emissions rather than evaporative emissions from motor vehicles or industrial sources. Including the sum of the two sources put the upper limit for tailpipe contributions at 60-70% of NMHC.

Combustion of agro-waste with coal in a fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Atimtay, Aysel T. [Middle East Technical University, Department of Environmental Engineering, Ankara (Turkey)

2010-02-15

In this study, a review of the studies done on the co-combustion of some agro-waste in a bubbling fluidized bed combustor (BFBC) having an inside diameter of 102 mm and a height of 900 mm is given. The agro-waste used to investigate the co-combustion characteristics were peach and apricot stones produced as a waste from the fruit juice industry, and olive cake produced as a waste from the olive oil industry. These are typical wastes for a Mediterranean country. A lignite coal was used for co-combustion. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub x} and total hydrocarbons (C{sub m} H{sub n}) were measured in the flue gas during combustion experiments. Variations of emissions of various pollutants were studied by changing the operating parameters (excess air ratio, fluidization velocity and fuel feed rate). Temperature distribution along the bed was measured with thermocouples. Emissions were also monitored from the exhaust. Various combinations of coal and biomass mixtures were tested. During the combustion tests, it was observed that the volatile matter from the biomass quickly volatilizes and mostly burns in the freeboard. The temperature profiles along the bed and the freeboard also confirmed this phenomenon. It was found that as the volatile matter of the biomass increases, combustion takes place more in the freeboard region. Better combustion conditions occur at higher excess air ratios. The results showed that co-combustion with these three proposed biomasses lowers the SO{sub 2} and NO{sub x} emissions considerably. CO and hydrocarbon emissions are lower at the higher excess air ratios. (orig.)

Concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and Major and Trace Elements in Simulated Rainfall Runoff from Parking Lots, Austin, Texas, 2003

National Research Council Canada - National Science Library

Mahler, Barbara J; Van Metre, Peter C; Wilson, Jennifer T

2004-01-01

Samples of creek bed sediment collected near seal-coated parking lots in Austin, Texas, by the City of Austin during 2001-02 had unusually elevated concentrations of polycyclic aromatic hydrocarbons (PAHs...

Hydrocarbons (aliphatic and aromatic) in the snow-ice cover in the Arctic

International Nuclear Information System (INIS)

Nemirovskaya, I.A.; Novigatsky, A.N.; Kluvitkin, A.A.

2002-01-01

This paper presented the concentration and composition of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in snow and ice-infested waters in the France-Victoria trough in the northern Barents Sea and in the Mendeleev ridge in the Amerasian basin of the Arctic Ocean. Extreme conditions such as low temperatures, ice sheets and the polar nights render the arctic environment susceptible to oil spills. Hydrocarbons found in these northern seas experience significant transformations. In order to determine the sources, pathways and transformations of the pollutants, it is necessary to know their origin. Hydrocarbon distributions is determined mostly by natural hydrobiological and geochemical conditions. The regularity of migration is determined by natural factors such as formation and circulation of air and ice drift. There is evidence suggesting that the hydrocarbons come from pyrogenic sources. It was noted that hydrocarbons could be degraded even at low temperatures. 17 refs., 1 tab

Occurrence and Sources of Aliphatic Hydrocarbons in Soils within ...

African Journals Online (AJOL)

ADOWIE PERE

Keywords: Asphalt Plants; Soil; Aliphatic hydrocarbons; Pristane; Phytane. Hot mix asphalt (HMA) plant is an assemblage of mechanical equipment where aggregates or inert mineral materials such as sand, gravel, crushed stones, Slag, rock dust or powder are blended, heated, dried and mixed with bitumen in measured ...

Studies on the effect of petroleum hydrocarbon on the microbial and ...

African Journals Online (AJOL)

SERVER

2007-08-20

Aug 20, 2007 ... Key words: Hydrocarbon, microbial counts, physico-chemical characteristics. INTRODUCTION. Petroleum ... carbons, whose composition also varies with the source. ... hydrocarbons into aquifers can lead to concentrations of.

Aliphatic and polycyclic aromatic hydrocarbons in Gulf of Trieste sediments (northern Adriatic): potential impacts of maritime traffic.

Science.gov (United States)

Bajt, Oliver

2014-09-01

The Gulf of Trieste (northern Adriatic) is one of the most urbanized and industrialized areas in the northern Adriatic, with intense maritime traffic experienced at multiple ports. The impact of maritime traffic on contamination by hydrocarbons in this area was assessed. Concentrations of hydrocarbons were higher near the expected contamination sources and still elevated in the adjacent offshore areas. Aliphatic hydrocarbons were mainly of petrogenic origin, with some contribution of biogenic origin. A continuous contamination by aliphatic hydrocarbons and degradation processes were hypothesized. Concentrations of total polycyclic aromatic hydrocarbons (PAH) were generally greater near the contamination sources. Compared to the prevailing pyrolytic origin, the petrogenic PAH origin seemed to be less important, but not negligible. Results revealed that intensive maritime traffic is a probable source of contamination by hydrocarbons in the investigated area, which is largely limited to areas near the contamination sources.

Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

International Nuclear Information System (INIS)

Xu Hui; Li Qin; Shen Lifeng; Zhang Mengqun; Zhai Jianping

2010-01-01

In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

Experimental Simulation of Methane Hydrate Extraction at High Pressure Conditions: Influence of the Sediment Bed

Science.gov (United States)

Agudo, J. R.; Park, J.; Luzi, G.; Williams, M.; Rauh, C.; Wierschem, A.; Delgado, A.

2017-10-01

Being a clean alternative to other fossil fuels, Methane Hydrate (MH) is currently considered as one of the most important potential sources for hydrocarbon fuels [1]. In addition, the high energy density of MH and its stability at higher temperatures as compared to LNG (Liquefied Natural Gas) makes MH a potential greener method for energy transportation. At the same time, the low thermodynamic stability of MH strongly questions the future exploitation of gas hydrate deposits, turning its extraction into a possible geohazard [2]. Fluctuations in pressure, temperature, salinity, degree of saturation or sediment bed properties may cause methane gas release from the water lattice. We experimentally study the influence of the sediment bed geometry during formation-dissociation of MH. For this purpose, MH is synthesized within regular substrates in a 93 cm3 high pressure vessel. The regular substrates are triangular and quadratic arrangements of identical glass spheres with a diameter of 2 and 5 mm, respectively. MH formation within regular substrate reduces the possibility of spontaneous nucleation to a unique geometrical configuration. This fact permits us to characterize the kinetics of MH formation-dissociation as a function of the sediment bed geometry. Preliminary experimental results reveal a strong dependence of MH formation on the geometry of the regular substrate. For instance, under the same pressure and temperature, the kinetics of MH production is found to change by a factor 3 solely depending on the substrate symmetry, i.e. triangular or quadratic.

Hydrocarbons cocktails of the future

International Nuclear Information System (INIS)

Anon.

2004-01-01

This publication of the Areva Group, a world nuclear industry leader, provides information on the energy in many domains. This issue deals with the CO 2 pollution exchange, the carbon sinks to compensate the CO 2 , the green coal as an innovative solution, an outsize dam in China, the solar energy progresses in France and the french medicine academy in favor of Nuclear. A special chapter is devoted to the hydrocarbons of the future, artificial chemical combination created from constituents of hydrocarbons and derived from various sources. (A.L.B.)

Process for in-situ biodegradation of hydrocarbon contaminated soil

International Nuclear Information System (INIS)

Ely, D.L.; Heffner, D.A.

1991-01-01

This patent describes an in situ process for biodegrading hydrocarbons by drawing oxygen into an undisturbed hydrocarbon contaminated zone in a fluid permeable soil. It comprises: establishing a borehole extending from the earth's surface through a hydrocarbon contaminated zone having hydrocarbon degrading microbes therein; lining the borehole with a fluid impermeable liner coaxially spaced and sealingly connected to the inside surface of the borehole and extending from the earth's surface to the hydrocarbon-contaminated zone; the liner including a fluid permeable portion extending from the lower end thereof and through at least a portion of the hydrocarbon contaminated zone, fluidly connecting a source of negative pressure to the fluid impermeable line; evacuating gas from the borehole through the fluid permeable portion of the liner at a rate sufficient to draw air from the earth's surface into the hydrocarbon containing zone; and adjusting the flow rate of the evacuated gas so that the amount of hydrocarbon biodegradation therein is within 50% of the maximum hydrocarbon biodegradation rate as detected by the volume of carbon dioxide in the evacuated gas

Converting of oil shale and biomass into liquid hydrocarbons via pyrolysis

International Nuclear Information System (INIS)

Kılıç, Murat; Pütün, Ayşe Eren; Uzun, Başak Burcu; Pütün, Ersan

2014-01-01

Highlights: • Co-processing of oil shale with an arid land biomass for hydrocarbon production. • Co-pyrolysis in TGA and fixed-bed reactor. • Characterization of oil and char. - Abstract: In this study, co-pyrolytic behaviors of oil shale and Euphorbia rigida were investigated at different temperatures in a fixed bed reactor at 450, 500, and 550 °C with a heating rate of 10 °C/min in the presence of nitrogen atmosphere. The obtained solid product (char) and liquid product (tar) were analyzed by using different types of characterization techniques. Experimental results showed co-pyrolysis of oil shale and biomass could be an environmental friendly way for the transformation of these precursors into valuable products such as chemicals or fuels

Distribution of discontinuous mudstone beds within wave-dominated shallow-marine deposits: Star Point Sandstone and Blackhawk Formation, Eastern Utah, USA

OpenAIRE

Eide, Christian; Buckley, Simon; Howell, John

2017-01-01

Deposits of wave-dominated shorelines are typically considered to act as relatively simple hydrocarbon reservoirs and are commonly modeled as “tanks of sand”. However, important heterogeneities that can act as barriers to fluid flow occur at the parasequence, bedset and bed scales, especially in viscous oil or low permeability oil fields. Heterogeneities at the parasequence and bedset scale have been well-studied, but discontinuous mudstone-beds occurring within the shoreface have received li...

Seawater-cultured Botryococcus braunii for efficient hydrocarbon extraction.

Directory of Open Access Journals (Sweden)

Kenichi Furuhashi

Full Text Available As a potential source of biofuel, the green colonial microalga Botryococcus braunii produces large amounts of hydrocarbons that are accumulated in the extracellular matrix. Generally, pretreatment such as drying or heating of wet algae is needed for sufficient recoveries of hydrocarbons from B. braunii using organic solvents. In this study, the Showa strain of B. braunii was cultured in media derived from the modified Chu13 medium by supplying artificial seawater, natural seawater, or NaCl. After a certain period of culture in the media with an osmotic pressure corresponding to 1/4-seawater, hydrocarbon recovery rates exceeding 90% were obtained by simply mixing intact wet algae with n-hexane without any pretreatments and the results using the present culture conditions indicate the potential for hydrocarbon milking.Seawater was used for efficient hydrocarbon extraction from Botryococcus braunii. The alga was cultured in media prepared with seawater or NaCl. Hydrocarbon recovery rate exceeding 90% was obtained without any pretreatment.

Geology and oil and gas assessment of the Fruitland Total Petroleum System, San Juan Basin, New Mexico and Colorado: Chapter 6 in Geology and Oil and Gas Assessment of the Fruitland Total Petroleum System, San Juan Basin, New Mexico and Colorado

Science.gov (United States)

Ridgley, J.L.; Condon, S.M.; Hatch, J.R.

2013-01-01

The Fruitland Total Petroleum System (TPS) of the San Juan Basin Province includes all genetically related hydrocarbons generated from coal beds and organic-rich shales in the Cretaceous Fruitland Formation. Coal beds are considered to be the primary source of the hydrocarbons. Potential reservoir rocks in the Fruitland TPS consist of the Upper Cretaceous Pictured Cliffs Sandstone, Fruitland Formation (both sandstone and coal beds), and the Farmington Sandstone Member of the Kirtland Formation, and the Tertiary Ojo Alamo Sandstone, and Animas, Nacimiento, and San Jose Formations.

Two-step processing of oil shale to linear hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Eliseev, O.L.; Ryzhov, A.N.; Latypova, D.Zh.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Avakyan, T.A. [Gubkin Russian State University of Oil and Gas, Moscow (Russian Federation)

2013-11-01

Thermal and catalytic steam reforming of oil shale mined from Leningrad and Kashpir deposits was studied. Experiments were performed in fixed bed reactor by varying temperature and steam flow rate. Data obtained were approximated by empirical formulas containing some parameters calculated by least-squares method. Thus predicting amount of hydrogen, carbon monoxide and methane in producer gas is possible for given particular kind of oil shale, temperature and steam flow rate. Adding Ni catalyst enriches hydrogen and depletes CO content in effluent gas at low gasification temperatures. Modeling gas simulating steam reforming gases (H{sub 2}, CO, CO{sub 2}, and N{sub 2} mixture) was tested in hydrocarbon synthesis over Co-containing supported catalyst. Selectivity of CO conversion into C{sub 5+} hydrocarbons reaches 84% while selectivity to methane is 7%. Molecular weight distribution of synthesized alkanes obeys Anderson-Schulz-Flory equation and chain growth probability 0.84. (orig.)

Interplay between spatially explicit sediment sourcing, hierarchical river-network structure, and in-channel bed material sediment transport and storage dynamics

Science.gov (United States)

Czuba, Jonathan A.; Foufoula-Georgiou, Efi; Gran, Karen B.; Belmont, Patrick; Wilcock, Peter R.

2017-05-01

Understanding how sediment moves along source to sink pathways through watersheds—from hillslopes to channels and in and out of floodplains—is a fundamental problem in geomorphology. We contribute to advancing this understanding by modeling the transport and in-channel storage dynamics of bed material sediment on a river network over a 600 year time period. Specifically, we present spatiotemporal changes in bed sediment thickness along an entire river network to elucidate how river networks organize and process sediment supply. We apply our model to sand transport in the agricultural Greater Blue Earth River Basin in Minnesota. By casting the arrival of sediment to links of the network as a Poisson process, we derive analytically (under supply-limited conditions) the time-averaged probability distribution function of bed sediment thickness for each link of the river network for any spatial distribution of inputs. Under transport-limited conditions, the analytical assumptions of the Poisson arrival process are violated (due to in-channel storage dynamics) where we find large fluctuations and periodicity in the time series of bed sediment thickness. The time series of bed sediment thickness is the result of dynamics on a network in propagating, altering, and amalgamating sediment inputs in sometimes unexpected ways. One key insight gleaned from the model is that there can be a small fraction of reaches with relatively low-transport capacity within a nonequilibrium river network acting as "bottlenecks" that control sediment to downstream reaches, whereby fluctuations in bed elevation can dissociate from signals in sediment supply.

Aromatic hydrocarbon concentrations in sediments of Placentia Bay, Newfoundland

International Nuclear Information System (INIS)

Kiceniuk, J.W.

1992-01-01

A study was conducted to examine the potential for contamination of recent sediments with polycyclic aromatic hydrocarbons due to tanker and refinery activity in Placentia Bay, Newfoundland, an area without large local anthropogenic sources of aromatics. Sediment samples were taken from the vicinity of the Come By Chance refinery, Woody Island, Wild Cove, and Port Royal Arm, all in the north end of the bay. The samples were extracted by two methods, dichloromethane extraction of dried sediment for determination of total aromatic hydrocarbon content and hexane extraction of wet sediment for estimation of the bioavailability of hydrocarbons and determination of more volatile compounds. Class analysis of aromatic hydrocarbons was conducted on a NH 2 column with detection at 255 nm. Total concentrations of di-tricyclic aromatics were highest at the Woody Island site (0.6 μg/g). The sediments from the Come By Chance site, Wild Cove, and Port Royal Arm sediments contained 0.3, 0.1, and 0.2 μg/g respectively. The hexane extracts from Come By Chance were lowest in di-tricyclic aromatics (0.007 μg/g), with the other sites being equal in concentration (0.01 μg/g). It is evident from the study that aromatic hydrocarbon concentrations in Placentia Bay are elevated in some parts of the bay in the absence of local combustion sources, and that the most likely source is petroleum. 12 refs., 5 figs., 2 tabs

Occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal marine sediments along the shoreline of Douglas Channel to Hecate Strait in British Columbia.

Science.gov (United States)

Yang, Zeyu; Hollebone, Bruce P; Laforest, Sonia; Lambert, Patrick; Brown, Carl E; Yang, Chun; Shah, Keval; Landriault, Mike; Goldthorp, Michael

2017-09-15

The occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal zone along the northern British shoreline were evaluated based on analyzing total petroleum hydrocarbons (TPH), n-alkanes, petroleum related biomarkers such as terpanes and steranes, and polycyclic aromatic hydrocarbons (PAHs) including non-alkylated and alkylated homologues (APAHs). The TPH levels, n-alkanes, petroleum biomarkers and PAHs in all the sampling sites, except for Masset Harbor/York Point at Gil Island were low, without obvious unresolved complex mixture (UCM) and petroleum contamination input. Specifically, n-alkanes showed a major terrestrial plants input; PAHs with abundant non-alkylated PAHs but minor APAHs showed a major pyrogenic input. However, obvious petroleum-derived hydrocarbons have impacted Masset Harbor. A historical petroleum input was found in York Point at Gil Island, due to the presence of the low level of petroleum biomarkers. Ecological assessment of 13 non-alkylated PAHs in Masset Harbor indicated no potential toxicity to the benthic organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular indicators for palaeoenvironmental change in a Messinian evaporitic sequence (Vena del Gesso, Italy). II: High-resolution variations in abundances and 13C contents of free and sulphur-bound carbon skeletons in a single marl bed

Science.gov (United States)

Kenig, F.; Damste, J. S.; Frewin, N. L.; Hayes, J. M.; De Leeuw, J. W.

1995-01-01

The extractable organic matter of 10 immature samples from a marl bed of one evaporitic cycle of the Vena del Gesso sediments (Gessoso-solfifera Fm., Messinian, Italy) was analyzed quantitatively for free hydrocarbons and organic sulphur compounds. Nickel boride was used as a desulphurizing agent to recover sulphur-bound lipids from the polar and asphaltene fractions. Carbon isotopic compositions (delta vs PDB) of free hydrocarbons and of S-bound hydrocarbons were also measured. Relationships between these carbon skeletons, precursor biolipids, and the organisms producing them could then be examined. Concentrations of S-bound lipids and free hydrocarbons and their delta values were plotted vs depth in the marl bed and the profiles were interpreted in terms of variations in source organisms, 13 C contents of the carbon source, and environmentally induced changes in isotopic fractionation. The overall range of delta values measured was 24.7%, from -11.6% for a component derived from green sulphur bacteria (Chlorobiaceae) to -36.3% for a lipid derived from purple sulphur bacteria (Chromatiaceae). Deconvolution of mixtures of components deriving from multiple sources (green and purple sulphur bacteria, coccolithophorids, microalgae and higher plants) was sometimes possible because both quantitative and isotopic data were available and because either the free or S-bound pool sometimes appeared to contain material from a single source. Several free n-alkanes and S-bound lipids appeared to be specific products of upper-water-column primary producers (i.e. algae and cyanobacteria). Others derived from anaerobic photoautotrophs and from heterotrophic protozoa (ciliates), which apparently fed partly on Chlorobiaceae. Four groups of n-alkanes produced by algae or cyanobacteria were also recognized based on systematic variations of abundance and isotopic composition with depth. For hydrocarbons probably derived from microalgae, isotopic variations are well correlated with

Hydrocarbon potential of Ordovician and Silurian rocks. Siljan Region (Sweden)

Energy Technology Data Exchange (ETDEWEB)

Berner, U. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Lehnert, O. [Erlangen-Nuernberg Univ., Erlangen (Germany); Meinhold, G. [Goettingen Univ. (Germany)

2013-08-01

Hydrocarbon exploration in the vicinity of Europe's largest impact structure (Siljan, Central Sweden) focused for years on abiogenic concepts and largely neglected state of the art knowledge on hydrocarbon generation via thermal decomposition of organic matter. In our study we use sedimentary rocks obtained from three drill sites (Mora001, Stumsnaes 1 and Solberga 1) within the ring structure around the central uplift to investigate the hydrocarbon potential of Ordovician and Silurian strata of the region and also for comparison with the shale oil and gas potential of age equivalent rocks of the Baltic Sea. Elemental analyses provided information on concentrations of carbonate and organic carbon, total sulfur as well as on the composition of major and minor elements of the sediments. The data has been used to evaluate the depositional environment and possible diagenetic alterations of the organic matter. RockEval pyrolysis and solvent hydrocarbon extraction gave insight into the hydrocarbon generation potential and the type and thermal maturity of the sediments. From the geochemistry data of the studied wells it is obvious that changes of depositional environments (lacustrine - marine) have occurred during Ordovician and Silurian times. Although, the quality of the organic matter has been influenced in marine and brackish environments through sulfate reduction, we observe for a number of marine and lacustrine sediments a good to excellent preservation of the biological precursors which qualify the sediments as hydrocarbon source rocks (Type II kerogens). Lacustrine source rocks show a higher remaining hydrocarbon potential (up to {proportional_to}550 mg HC per g C{sub org}) than those of marine or brackish environments. Our investigations indicate that the thermal maturity of organic matter of the drill sites has reached the initial stage of oil generation. However, at Mora001 some of the sediments were stained with oil indicating that hydrocarbons have

Geology and oil and gas assessment of the Mancos-Menefee Composite Total Petroleum System: Chapter 4 in Total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado

Science.gov (United States)

Ridgley, J.L.; Condon, S.M.; Hatch, J.R.

2013-01-01

The Mancos-Menefee Composite Total Petroleum System (TPS) includes all genetically related hydrocarbons generated from organic-rich shales in the Cretaceous Mancos Shale and from carbonaceous shale, coal beds, and humate in the Cretaceous Menefee Formation of the Mesaverde Group. The system is called a composite total petroleum system because the exact source of the hydrocarbons in some of the reservoirs is not known. Reservoir rocks that contain hydrocarbons generated in Mancos and Menefee source beds are found in the Cretaceous Dakota Sandstone, at the base of the composite TPS, through the lower part of the Cliff House Sandstone of the Mesaverde Group, at the top. Source rocks in both the Mancos Shale and Menefee Formation entered the oil generation window in the late Eocene and continued to generate oil or gas into the late Miocene. Near the end of the Miocene in the San Juan Basin, subsidence ceased, hydrocarbon generation ceased, and the basin was uplifted and differentially eroded. Reservoirs are now underpressured.

Surfactant-enhanced recovery of dissolved hydrocarbons at petroleum production facilities

International Nuclear Information System (INIS)

Freeman, J.T.; Mayes, M.; Wassmuth, F.; Taylor, K.; Rae, W.; Kuipers, F.

1997-01-01

The feasibility and cost effectiveness of surfactant-enhanced pumping to reduce source concentrations of petroleum hydrocarbons from contaminated soils was discussed. Light non-aqueous phase liquids (LNAPL) hydrocarbons are present beneath many petroleum production processing facilities in western Canada. Complete removal of LNAPLs from geologic materials is difficult and expensive. Treatment technologies include costly ex-situ methods such as excavation and in-situ methods such as physical extraction by soil venting and pumping, bioremediation, and combination methods such as bioventing, bioslurping or air sparging. Surfactant-aided pumping can reduce source hydrocarbon concentrations when used in conjunction with traditional pump and treat, or deep well injection. This study involved the selection of an appropriate surfactant from a wide variety of commercially available products. A site contaminated by hydrocarbons in Turner Valley, Alberta, was used for field scale testing. One of the major problems was quantifying the increase in the dissolved hydrocarbon concentrations in the recovered water once a surfactant was added. From the 30 surfactants screened in a series of washing and oil solubilization tests, two surfactants, Brij 97 and Tween 80, were selected for further evaluation. Increased hydrocarbon recovery was observed within 10 days of the introduction of the first surfactant. 2 refs., 7 figs

Differentiation of naturally-occurring vs. artificial hydrocarbons in a landfill groundwater investigation

International Nuclear Information System (INIS)

Beaver, J.L.; Hartness, J.A.; Breeding, L.B.; Buchanan, D.M.

1994-01-01

Interpretation of groundwater sampling data at a large municipal/industrial landfill indicates contamination by both artificial and naturally-occurring hydrocarbons. Site hydrogeology consists of three different water bearing zones. The uppermost (shallow) aquifer is an unconfined unit consisting of silt, clay, and sand deposits. An intermediate depth semiconfined aquifer underlies the unconfined unit, and consists of a chert rubble zone and the upper portion of a fractured and solution-enhanced limestone formation. A regionally-extensive organic-rich shale underlies the semiconfined aquifer and separates it from the deep confined aquifer, which also consists of limestone. Groundwater investigations at the landfill have detected chlorinated and non-chlorinated hydrocarbons in the different aquifer intervals. Chlorinated hydrocarbons detected include tetrachloroethene, dichloroethene, and vinyl chloride and occur almost exclusively in the shallow aquifer. Aromatic hydrocarbons detected include benzene, toluene, ethylbenzene, and xylene (BTEX) and-occur in the intermediate and deep aquifers. The landfill was originally interpreted as the source of the contaminants. The observation of free-phase liquid hydrocarbons in the intermediate aquifer at the site, and high dissolved BTEX levels in the deep and intermediate aquifers upgradient of the landfill suggest that the aromatics were derived from a source other than the landfill. A potential source of BTEX contamination may be abandoned (pre-1930) natural gas wells located near the landfill. An additional BTEX source may be the organic-rich shale formation (a documented petroleum source rock)

Air gasification of agricultural waste in a fluidized bed gasifier: hydrogen production performance

Energy Technology Data Exchange (ETDEWEB)

Wan Ab Karim Ghani, W. A.; Moghadam, R. A.; Mohd Salleh, M. A. [Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Alias, A. B. [Chemical Engineering, Universiti Teknologi MARA Malaysia, 54500 Shah Alam, Selangor (Malaysia)

2009-07-01

Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell) by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900 {sup o}C), fluidization ratio (2 to 3.33 m/s), static bed height (10 to 30 mm) and equivalence ratio (0.16 to 0.46) were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol%) could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900 {sup o}C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidising velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced. (author)

Air Gasification of Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance

Directory of Open Access Journals (Sweden)

A. B. Alias

2009-05-01

Full Text Available Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900°C, fluidization ratio (2 to 3.33 m/s, static bed height (10 to 30 mm and equivalence ratio (0.16 to 0.46 were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol% could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900°C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidizing velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced.

Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China

International Nuclear Information System (INIS)

Ying Liu; Ling Chen; Zhao Jianfu; Huang Qinghui; Zhu Zhiliang; Gao Hongwen

2008-01-01

Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration of the Suzhou River was close to the average concentration of the Huangpu River. PAHs source analysis suggested that, in the Yangtze Estuary, PAHs at locations far away from cities were mainly from petrogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. In the Huangpu and Suzhou Rivers, pyrogenic input outweighed other sources. The pyrogenic PAHs in the upper reaches of the Huangpu River were mainly from the incomplete combustion of grass, wood and coal, and those in the middle and lower reaches were from vehicle and vessel exhaust. - Surface sediments of two rivers and an estuary in Shanghai were contaminated by PAHs

Reference repository design concept for bedded salt

Energy Technology Data Exchange (ETDEWEB)

Carpenter, D.W.; Martin, R.W.

1980-10-08

A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

Reference repository design concept for bedded salt

International Nuclear Information System (INIS)

Carpenter, D.W.; Martin, R.W.

1980-01-01

A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood

Source Apportionment of Particle Bound Polycyclic Aromatic Hydrocarbons at an Industrial Location in Agra, India

Directory of Open Access Journals (Sweden)

Anita Lakhani

2012-01-01

Full Text Available 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs were quantified in total suspended ambient particulate matter (TSPM collected from an industrial site in Agra (India using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m−3. Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline.

Source Apportionment of Suspended Sediment Sources using 137Cs and 210Pbxs

Science.gov (United States)

Lamba, J.; Karthikeyan, K.; Thompson, A.

2017-12-01

A study was conducted in the Pleasant Valley Watershed (50 km 2) in South Central Wisconsin to better understand sediment transport processes using sediment fingerprinting technique. Previous studies conducted in this watershed showed that resuspension of fine sediment deposited on the stream bed is an important source of suspended sediment. To better understand the role of fine sediment deposited on the stream bed, fallout radionuclides,137Cs and 210Pbxs were used to determine relative contribution to suspended sediment from in-stream (stream bank and stream bed) and upland sediment sources. Suspended sediment samples were collected during the crop growing season. Potential sources of suspended sediment considered in this study included cropland, pasture and in-stream (stream bed and stream bank). Suspended sediment sources were determined at a subwatershed level. Results of this study showed that in-stream sediment sources are important sources of suspended sediment. Future research should be conducted to better understand the role of legacy sediment in watershed-level sediment transport processes.

New Insight into the Kinetics of Deep Liquid Hydrocarbon Cracking and Its Significance

Directory of Open Access Journals (Sweden)

Wenzhi Zhao

2017-01-01

Full Text Available The deep marine natural gas accumulations in China are mainly derived from the cracking of liquid hydrocarbons with different occurrence states. Besides accumulated oil in reservoir, the dispersed liquid hydrocarbon in and outside source also is important source for cracking gas generation or relayed gas generation in deep formations. In this study, nonisothermal gold tube pyrolysis and numerical calculations as well as geochemical analysis were conducted to ascertain the expulsion efficiency of source rocks and the kinetics for oil cracking. By determination of light liquid hydrocarbons and numerical calculations, it is concluded that the residual bitumen or hydrocarbons within source rocks can occupy about 50 wt.% of total oil generated at oil generation peak. This implies that considerable amounts of natural gas can be derived from residual hydrocarbon cracking and contribute significantly to the accumulation of shale gas. Based on pyrolysis experiments and kinetic calculations, we established a model for the cracking of oil and its different components. In addition, a quantitative gas generation model was also established to address the contribution of the cracking of residual oil and expulsed oil for natural gas accumulations in deep formations. These models may provide us with guidance for gas resource evaluation and future gas exploration in deep formations.

Petrography of thoriferous hydrocarbon nodules in sandstones, and their significance for petroleum exploration

International Nuclear Information System (INIS)

Parnell, J.; Monson, B.; Tosswill, R.J.

1990-01-01

Nodules of thorium-rich hydrocarbon are recorded in sandstone sequences from several basins. The hydrocarbon nodules contain mineral inclusions, particularly of thorite or monazite. There is evidence both for accretion of hydrocarbons around detrital heavy mineral grains and for epigenetic growth by interaction of hydrocarbons with thorium-bearing fluids. Both mechanisms depend upon the precipitation of solid hydrocarbons induced by irradiation from thorium. The nodules exhibit aggressive replacement of other grains, a characteristic of radioanomalous hydrocarbons. The occurrence of the nodules is dependent upon an appropriate (plutonic) source for the thorium, but given this constraint they are important evidence for hydrocarbon migration pathways. (author)

GOM Deepwater Horizon Oil Spill: A Time Series Analysis of Variations in Spilled Hydrocarbons

Science.gov (United States)

Palomo, C. M.; Yan, B.

2013-12-01

An estimated amount of 210 million gallons of crude oil was released into the Gulf of Mexico (GOM) from April 20th to July 15th 2010 during the Deepwater Horizon oil rig explosion. The spill caused a tremendous financial, ecological, environmental and health impact and continues to affect the GOM today. Variations in hydrocarbons including alkanes, hopanes and poly-cyclic aromatic hydrocarbons (PAHs) can be analyzed to better understand the oil spill and assist in oil source identification. Twenty-one sediment samples*, two tar ball samples and one surface water oil sample were obtained from distinct locations in the GOM and within varying time frames from May to December 2010. Each sample was extracted through the ASE 200 solvent extractor, concentrated down under nitrogen gas, purified through an alumina column, concentrated down again with nitrogen gas and analyzed via GC X GC-TOF MS. Forty-one different hydrocarbons were quantified in each sample. Various hydrocarbon 'fingerprints,' such as parental :alkylate PAH ratios, high molecular weight PAHs: low molecular weight alkane ratios, and carbon preference index were calculated. The initial objective of this project was to identify the relative hydrocarbon contributions of petrogenic sources and combustion sources. Based on the calculated ratios, it is evident that the sediment core taken in October of 2010 was greatly affected by combustion sources. Following the first month of the spill, oil in the gulf was burned in attempts to contain the spill. Combustion related sources have quicker sedimentation rates, and hydrocarbons from a combustion source essentially move into deeper depths quicker than those from a petrogenic source, as was observed in analyses of the October 2010 sediment. *Of the twenty-one sediment samples prepared, nine were quantified for this project.

Experimental, kinetic and numerical modeling of hydrogen production by catalytic reforming of crude ethanol over a commercial catalyst in packed bed tubular reactor and packed bed membrane reactor

International Nuclear Information System (INIS)

Aboudheir, Ahmed; Akande, Abayomi; Idem, Raphael

2006-01-01

The demand for hydrogen energy has increased tremendously in recent years essentially because of the increase in the word energy consumption as well as recent developments in fuel cell technologies. The energy information administration has projected that world energy consumption will increase by 59% over the next two decades, from 1999 to 2020, in which the largest share is still dominated by fossil fuels (oil, natural gas and coal). Carbon dioxide (CO 2 ) emissions resulting from the combustion of these fossil fuels currently are estimated to account for three-fourth of human-caused CO 2 emissions worldwide. Greenhouse gas emission, including CO 2 , should be limited, as recommended at the Kyoto Conference, Japan, in December 1997. In this regard, hydrogen (H 2 ) has a significant future potential as an alternative fuel that can solve the problems of CO 2 emissions as well as the emissions of other air contaminants. One of the techniques to produce hydrogen is by reforming of hydrocarbons or biomass. Crude ethanol (a form of biomass, which essentially is fermentation broth) is easy to produce, is free of sulphur, has low toxicity, and is also safe to handle, transport and store. In addition, crude ethanol consists of oxygenated hydrocarbons, such as ethanol, lactic acid, glycerol, and maltose. These oxygenated hydrocarbons can be reformed completely to H 2 and CO 2 , the latter of which could be separated from H 2 by membrane technology. This provides for CO 2 capture for eventual storage or destruction. In the case of using crude ethanol, this will result in negative CO 2 , emissions. In this paper, we conducted experimental work on production of hydrogen by the catalytic reforming of crude ethanol over a commercial promoted Ni-based catalyst in a packed bed tubular reactor as well as a packed bed membrane reactor. As well, a rigorous numerical model was developed to simulate this process in both the catalytic packed bed tubular reactor and packed bed membrane

Historical polycyclic aromatic and petrogenic hydrocarbon loading in Northern Central Gulf of Mexico shelf sediments.

Science.gov (United States)

Overton, E B; Ashton, B M; Miles, M S

2004-10-01

The distribution of selected hydrocarbons within ten dated sediment cores taken from the Mississippi River Bight off coastal Louisiana suggests a chronic contaminant loading from several sources including the river itself, oil and gas exploration in the central Gulf of Mexico (GOM) shelf area, and natural geologic hydrocarbon seeps. Data were grouped as either total polycyclic aromatic hydrocarbons (PAH's), which were indicative of pyrogenic PAH's; or estimated total hopanes (indicative of petrogenic hydrocarbons). The total PAH concentrations and estimated total hopanes begin increasing above background levels (approximately 200 ng g(-1)) after the 1950s. The distribution of these hydrocarbons and hopanes within the dated sediment cores suggests that the Mississippi River is a regional source of pyrogenic PAH's, and that the hopanes are from natural geologic hydrocarbon seeps, oil and gas exploration in the GOM, or both.

Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

Directory of Open Access Journals (Sweden)

L. C. Marr

2006-01-01

Full Text Available Understanding sources, concentrations, and transformations of polycyclic aromatic hydrocarbons (PAHs in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and intercomparison of the methods. The three methods are (1 collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2 aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3 aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations of particle-phase PAHs typically peak at ~110 ng m-3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

An investigation of the physical and chemical changes occuring in a Fischer-Tropsch fixed bed catalyst during hydrocarbon synthesis

International Nuclear Information System (INIS)

Duvenhage, D.J.

1990-01-01

Deactivation studies: making use of fixed bed reactors, wet chemical analysis, surface area, pore volume determinations and X-ray diffraction spectrometry, scanning electron microscope spectrometry and secondary ion mass spectrometry techniques; were performed on a low temperature iron Fischer-Tropsch catalyst. It was revealed that this catalyst is mainly deactivated by sulphur poisoning, oxidation of the catalytic reactive phases, sintering of the iron crystallites and to a lesser extent deactivation through fouling of the catalytic surface by carbonaceous deposits. It was found that the top entry section of the catalyst bed deactivated relatively fast, the bottom exit section also deactivated, but not as fast as the top section. The central portion of the catalyst bed was least affected. Sulphur contaminants in the feed gas, even though present in only minute quantities, results in a loss of catalyst performance of the top section of the catalyst bed, while water, produced as a product from the Fischer-Tropsch reaction, oxidized and sintered the catalyst over the bottom section of the catalyst bed. 88 figs., 7 tabs., 224 refs

Some technical subjects on production of hydrocarbon fuel from synthetic gas

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Takashi

1987-06-20

Since fuel oil meeting the requirements of current petroleum products can be produced by SASOL F-T synthetic process, the manufacturing process of hydrocarbon fuel oil from the coal-derived synthesis gas, downstream processes are being successively investigated. Mobile M-gasoline, MTG, process which produces gasoline from the natural gas-derived synthesis gas through methanol went into commercial operation in New Zealand in 1986. Although the gasoline suffices the quality of commercial gasoline by both fixed bed and fluidized bed systems, the price and service life of catalyst and control of by-product durene must be improved. Any STG processes have not been completed yet and the yield and quality of gasoline are inferior to those of gasoline produced by the MTG process. Applying two-stage process, the STG process will be more economically effective.(21 refs, 4 figs, 10 tabs)

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

Science.gov (United States)

Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, V.; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, A.; Hellén, H.; Laakso, L.; Hakola, H.

2014-07-01

Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol, which affect human health, crop production and regional climate. Measurements of aromatic hydrocarbons were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (> 10 million people), the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anticyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for 1 year. Samples were collected twice a week for 2 h during daytime and 2 h during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median (mean) total aromatic hydrocarbon concentrations ranged between 0.01 (0.011) and 3.1 (3.2) ppb. Benzene levels did not exceed the local air quality standard limit, i.e. annual mean of 1.6 ppb. Toluene was the most abundant compound, with an annual median (mean) concentration of 0.63 (0.89) ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found, and no distinct seasonal patterns were

Characteristics of atmospheric non-methane hydrocarbons in Foshan City, China.

Science.gov (United States)

Tan, Jihua; Guo, Songjun; Ma, Yongliang; He, Kebin; Yang, Fumo; Yu, Yongchang; Wang, Jiewen

2011-12-01

Foshan is the most air-polluted city in Pearl River Delta. Non-methane hydrocarbons (NMHCs) were investigated for the first time in Foshan in winter 2008. Ethene, ethane, ethyne, propane, i-pentane, and toluene were the most abundant hydrocarbons and observed to be higher in Foshan than those in many other cities in China. Different from other cities, ethene and ethane were observed to be the two highest compounds in Foshan. Generally, the most abundant hydrocarbons showed high mixing ratios in the morning (0930-1030 hours), decreased to the lowest level in the afternoon (1430-1530 hours), and increased to higher value in the evening (1930-2030 hours). But i-pentane exhibited a different diurnal pattern with the highest level (13.4 ± 5.8 ppbv) in the afternoon, implying the acceleration of solvent evaporation resulting from higher temperature. Correlation coefficients (R(2) = 66% for n = 6 at 95% confidence level) of the individual hydrocarbons with ethyne and i-pentane indicated vehicular emissions were the main sources of ethene, propene, i-butene, isoprene, benzene and toluene, while gasoline evaporation was responsible for n-pentane, n-hexane, and n-heptane. The good correlation of most of the hydrocarbons with ethyne, indicating vehicular emissions, were the main sources of NMHCs. B/T ratio was 0.36 ± 0.06, implying vehicular emissions acted as the major contributors as well as additional emissions of toluene emitted from solvent usage. According to investigation, it also suggested that LPG leakage was the main source of propane, while NG leakage was responsible for ethane in Foshan City.

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

Science.gov (United States)

Lau, E. V.; Gan, S.; Ng, H. K.

2010-01-01

This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction. PMID:20396670

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

Directory of Open Access Journals (Sweden)

E. V. Lau

2010-01-01

Full Text Available This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.

Contribution of deep sourced carbon from hydrocarbon seeps to sedimentary organic carbon: Evidence from Δ14C and δ13C isotopes

Science.gov (United States)

Feng, D.; Peckmann, J.; Peng, Y.; Liang, Q.; Roberts, H. H.; Chen, D.

2017-12-01

Sulfate-driven anaerobic oxidation of methane (AOM) limits the release of methane from marine sediments and promotes the formation of carbonates close to the seafloor along continental margins. It has been established that hydrocarbon seeps are a source of dissolved inorganic and organic carbon to marine environments. However, questions remain about the contribution of deep sourced carbon from hydrocarbon seeps to the sedimentary organic carbon pool. For a number of hydrocarbon seeps from the South China Sea and the Gulf of Mexico, the portion of modern carbon was determined based on natural radiocarbon abundances (Δ14C) and stable carbon isotope (δ13Corganic carbon) compositions of the non-carbonate fractions extracted from authigenic carbonates. Samples from both areas show a mixing trend between ideal planktonic organic carbon (δ13C = -22‰ VPDB and 90% modern carbon) and the ambient methane. The δ13Corganic carbon values of non-carbonate fractions from three ancient seep deposits (northern Italy, Miocene; western Washington State, USA, Eocene to Oligocene) confirm that the proxy can be used to constrain the record of sulfate-driven AOM through most of Earth history by measuring the δ13C values of organic carbon. This study reveals the potential of using δ13C values of organic carbon to discern seep and non-seep environments. This new approach is particularly promising when authigenic carbonate is not present in ancient sedimentary environments. Acknowledgments: The authors thank BOEM and NOAA for their years' support of the deep-sea dives. Funding was provided by the NSF of China (Grants: 41422602 and 41373085).

Differentiating submarine channel-related thin-bedded turbidite facies: Outcrop examples from the Rosario Formation, Mexico

Science.gov (United States)

Hansen, Larissa; Callow, Richard; Kane, Ian; Kneller, Ben

2017-08-01

Thin-bedded turbidites deposited by sediment gravity flows that spill from submarine channels often contain significant volumes of sand in laterally continuous beds. These can make up over 50% of the channel-belt fill volume, and can thus form commercially important hydrocarbon reservoirs. Thin-bedded turbidites can be deposited in environments that include levees and depositional terraces, which are distinguished on the basis of their external morphology and internal architecture. Levees have a distinctive wedge shaped morphology, thinning away from the channel, and confine both channels (internal levees) and channel-belts (external levees). Terraces are flat-lying features that are elevated above the active channel within a broad channel-belt. Despite the ubiquity of terraces and levees in modern submarine channel systems, the recognition of these environments in outcrop and in the subsurface is challenging. In this outcrop study of the Upper Cretaceous Rosario Formation (Baja California, Mexico), lateral transects based on multiple logged sections of thin-bedded turbidites reveal systematic differences in sandstone layer thicknesses, sandstone proportion, palaeocurrents, sedimentary structures and ichnology between channel-belt and external levee thin-bedded turbidites. Depositional terrace deposits have a larger standard deviation in sandstone layer thicknesses than external levees because they are topographically lower, and experience a wider range of turbidity current sizes overspilling from different parts of the channel-belt. The thickness of sandstone layers within external levees decreases away from the channel-belt while those in depositional terraces are less laterally variable. Depositional terrace environments of the channel-belt are characterized by high bioturbation intensities, and contain distinctive trace fossil assemblages, often dominated by ichnofabrics of the echinoid trace fossil Scolicia. These assemblages contrast with the lower

Chemometric techniques in distribution, characterisation and source apportionment of polycyclic aromatic hydrocarbons (PAHS) in aquaculture sediments in Malaysia.

Science.gov (United States)

Retnam, Ananthy; Zakaria, Mohamad Pauzi; Juahir, Hafizan; Aris, Ahmad Zaharin; Zali, Munirah Abdul; Kasim, Mohd Fadhil

2013-04-15

This study investigated polycyclic aromatic hydrocarbons (PAHs) pollution in surface sediments within aquaculture areas in Peninsular Malaysia using chemometric techniques, forensics and univariate methods. The samples were analysed using soxhlet extraction, silica gel column clean-up and gas chromatography mass spectrometry. The total PAH concentrations ranged from 20 to 1841 ng/g with a mean of 363 ng/g dw. The application of chemometric techniques enabled clustering and discrimination of the aquaculture sediments into four groups according to the contamination levels. A combination of chemometric and molecular indices was used to identify the sources of PAHs, which could be attributed to vehicle emissions, oil combustion and biomass combustion. Source apportionment using absolute principle component scores-multiple linear regression showed that the main sources of PAHs are vehicle emissions 54%, oil 37% and biomass combustion 9%. Land-based pollution from vehicle emissions is the predominant contributor of PAHs in the aquaculture sediments of Peninsular Malaysia. Copyright © 2013 Elsevier Ltd. All rights reserved.

Conversion of oligomeric starch, cellulose, hydrolysates or sugars to hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Silks, Louis A; Sutton, Andrew; Kim, Jin Kyung; Gordon, John Cameron; Wu, Ruilian; Kimball, David B.

2017-09-05

Embodiments of the present invention are directed to the conversion of a source material (e.g., a depolymerized oligosaccharide mixture, a monomeric sugar, a hydrolysate, or a mixture of monomeric sugars) to intermediate molecules containing 7 to 26 contiguous carbon atoms. These intermediates may also be converted to saturated hydrocarbons. Such saturated hydrocarbons are useful as, for example, fuels.

Polycyclic Aromatic Hydrocarbons Identification and Source Discrimination in Rural Soil of the Northern Persian Gulf Coast

Directory of Open Access Journals (Sweden)

Fatemeh Valizadeh-kakhki

2014-01-01

Full Text Available Due to strategic situation of the Persian Gulf, identifying the petroleum pollution level and source is an important issue. Therefore, this paper enhanced fingerprinting method of applying biomarkers Polycyclic Aromatic Hydrocarbons (PAHs in identifying source and distribution of oil spills of the exposed areas. 10 soil samples collected from the northern coasts of the Persian Gulf along three provinces in the south of Iran. PAH concentrations in the soil ranged from 42.76 to 5596.49 ng.g-1. In the present study the distribution of 3 ringed PAHs was much higher than the other PAHs. Phenanthrene and alkylated derivatives of phenanthrene such as 3-methyl, 2-methyl, 9-methyl and 1-methyl phenanthrene were distinctively higher than the other components. According to the result PAHs concentration can be considered as no or little risk of toxicity for the organisms living in soil except for Fluoranthhene, comparing LD50. Applying marker ratios revealed that in most of the sampling sites showed perogenic sources and it emphasizes on the direct impact of oil and petroleum products to the lands due to oil well exploitation and transferring pipelines.

Air gasification of rice husk in bubbling fluidized bed reactor with bed heating by conventional charcoal.

Science.gov (United States)

Makwana, J P; Joshi, Asim Kumar; Athawale, Gaurav; Singh, Dharminder; Mohanty, Pravakar

2015-02-01

An experimental study of air gasification of rice husk was conducted in a bench-scale fluidized bed gasifier (FBG) having 210 mm diameter and 1600 mm height. Heating of sand bed material was performed using conventional charcoal fuel. Different operating conditions like bed temperature, feeding rate and equivalence ratio (ER) varied in the range of 750-850 °C, 25-31.3 kg/h, and 0.3-0.38, respectively. Flow rate of air was kept constant (37 m(3)/h) during FBG experiments. The carbon conversion efficiencies (CCE), cold gas efficiency, and thermal efficiency were evaluated, where maximum CCE was found as 91%. By increasing ER, the carbon conversion efficiency was decreased. Drastic reduction in electric consumption for initial heating of gasifier bed with charcoal compared to ceramic heater was ∼45%. Hence rice husk is found as a potential candidate to use directly (without any processing) in FBG as an alternative renewable energy source from agricultural field. Copyright © 2014 Elsevier Ltd. All rights reserved.

Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

Science.gov (United States)

Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

2012-11-01

Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

Energy Technology Data Exchange (ETDEWEB)

Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, Ville; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, Alex B.; Hellen, H.; Laakso, L.; Hakola, H.

2014-07-11

Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa) that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (>10 million people), the Vaal Triangle (e.g. petrochemical and industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours 1 during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass 2 selective detector was used for sample preparation and analysis. Results indicated that the 3 monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. 4 Benzene levels did not exceed local air quality standards. Toluene was the most abundant 5 species, with an annual median concentration of 0.63 ppb. No statistically significant 6 differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be

Investigation of Factors Influencing Dispersion of Liquid Hydrocarbons in Porous Media

Directory of Open Access Journals (Sweden)

Hussain Ali Baker

2016-08-01

Full Text Available An experimental work has been done to study the major factors that affect the axial dispersion of some hydrocarbons during liquid-liquid miscible displacement. Kerosene and gas oil are used as displacing phase while seven liquid hydrocarbons of high purity represent the displaced phase, three of the liquids are aromatics and the rest are of paraffinic base. In conducting the experiments, two packed beds of different porosity and permeability are used as porous media. The results showed that the displacement process is not a piston flow, breakthrough of displacing fluids are shown before one pore volume has been injected. The processes are stable with no evidence of viscous fingering. Dispersion model as adapted by Brigham et.al (1961 is used to determine the axial dispersion coefficient of displacing fluid. The results show an increasing in dispersion coefficient as the interstitial velocity and viscosity ratio increases.

Glacier seismology: eavesdropping on the ice-bed interface

Science.gov (United States)

Walter, F.; Röösli, C.

2015-12-01

Glacier sliding plays a central role in ice dynamics. A number of remote sensing and deep drilling initiatives have therefore focused on the ice-bed interface. Although these techniques have provided valuable insights into bed properties, they do not supply theorists with data of sufficient temporal and spatial resolution to rigorously test mathematical sliding laws. As an alternative, passive seismic techniques have gained popularity in glacier monitoring. Analysis of glacier-related seismic sources ('icequakes') has become a useful technique to study inaccessible regions of the cryosphere, including the ice-bed interface. Seismic monitoring networks on the polar ice sheets have shown that ice sliding is not only a smooth process involving viscous deformation and regelation of basal ice layers. Instead, ice streams exhibit sudden slip episodes over their beds and intermittent phases of partial or complete stagnation. Here we discuss new and recently published discoveries of basal seismic sources beneath various glacial bodies. We revisit basal seismicity of hard-bedded Alpine glaciers, which is not the result of pure stick-slip motion. Sudden changes in seismicity suggest that the local configuration of the subglacial drainage system undergoes changes on sub daily time scales. Accordingly, such observations place constraints on basal resistance and sliding of hard-bedded glaciers. In contrast, certain clusters of stick-slip dislocations associated with micro seismicity beneath the Greenland ice sheet undergo diurnal variations in magnitudes and inter event times. This is best explained with a soft till bed, which hosts the shear dislocations and whose strength varies in response to changes in subglacial water pressure. These results suggest that analysis of basal icequakes is well suited for characterizing glacier and ice sheet beds. Future studies should address the relative importance between "smooth" and seismogenic sliding in different glacial environments.

Mobile geophysics for searching and exploration of Domanic hydrocarbon deposits

Science.gov (United States)

Borovsky, M. Ya; Uspensky, B. V.; Valeeva, S. E.; Borisov, A. S.

2018-05-01

There are noted features of shale hydrocarbons occurrence. It is shown the role of geophysical prospecting in the geological prospecting process for non-traditional sources of hydrocarbon. There are considered the possibilities of non-seismic methods for forecasting, prospecting, exploration and preparation of Domanikovian hydrocarbons accumulations for exploration. It is emphasized the need for geophysical studies of tectonic disturbances. Modern aerogeophysical instrumentation and methodological support allows to combine high-precision magneto-prospecting with gravimetric and gamma spectrometry. This combination of geophysical methods contributes to the diagnosis of active and latent faults.

Aromatic hydrocarbons

International Nuclear Information System (INIS)

Roder, M.

1985-01-01

Papers dealing with radiolysis of aromatic hydrocarbons of different composition (from benzene to terphenyls and hydrocarbons with condensed rings) as well as their mixtures (with alkanes, alkenes, other aromatic hydrocarbons) are reviewed. High radiation stability of aromatic hydrocarbons in condensed phases associated with peculiarities of molecular structure of compounds is underlined. Mechanisms of radiolytic processes, vaues of product yields are considered

Hydrocarbon occurrence in NW Africa's MSGBC area

Energy Technology Data Exchange (ETDEWEB)

Reymond, A.; Negroni, P.

1989-06-01

The MSGBC (Mauritania, Senegal, The Gambia, Guinea-Bissau, Guinea Conakry) coastal basin has evolved as a passive margin from Jurassic time up to the present following a period of poorly known rifting of Permian to Middle Jurassic age. Structural configuration of the Paleozoic series is documented by large outcrops and a good number of seismic sections. Based on previous exploration efforts that found significant hydrocarbon shows, a comprehensive study of this African basin's source rocks, maturation evolution and petroleum generation potential was undertaken. About 1,000 geochemical analyses of the Paleozoic, Cretaceous and Tertiary series identified good source rocks in the Cenomano-Turonian, Silurian, Senonian and Paleocene ages. The parameters used to identify and characterize source rock are: Total organic carbon content (TOC) in percent and source potential (in kg HC/t), representing the amount of hydrocarbon generated per ton of rock and determined by Rock-Eval pyrolysis.

Assessment of plant-derived hydrocarbons. Final report

Energy Technology Data Exchange (ETDEWEB)

McFadden, K.; Nelson, S.H.

1981-09-30

A number of hydrocarbon producing plants are evaluated as possible sources of rubber, liquid fuels, and industrial lubricants. The plants considered are Euphorbia lathyris or gopher plant, milkweeds, guayule, rabbit brush, jojoba, and meadow foam. (ACR)

Geology and coal-bed methane resources of the northern San Juan Basin, Colorado and New Mexico

International Nuclear Information System (INIS)

Fassett, J.E.

1988-01-01

This guidebook is the first of its kind: A focused look at coal-bed methane in a large Rocky Mountain Laramide basin. The papers in this volume cover every aspect of coal-bed methane in the San Juan Basin, including: The geology, environments of deposition, and geometry of the coal beds that contain the resource; the origin and migration history of the gas; basin-wide resource estimates; the engineering aspects of getting the gas out of the ground; the marketing and economics of producing coal-bed methane in the San Juan Basin; the legal ownership of the gas; state regulations governing well spacing and field rules; disposal of produced water; and land and mineral ownership patterns in the northern part of the basin. Also included are detailed papers on all of the major coal-bed methane fields in the basin, and in a paper on the history of Fruitland gas production, a discussion of most of the not-so-major fields. A small section of the book deals with geophysical methods, as yet still experimental, for surface detection of underground hydrocarbon resources. Individual papers have been processed separately for inclusion on the data base

Microbial utilization of naturally occurring hydrocarbons at the Guaymas Basin hydrothermal vent site

International Nuclear Information System (INIS)

Bazylinski, D.A.; Wirsen, C.O.; Jannasch, H.W.

1989-01-01

The Guaymas Basin (Gulf of California; depth, 2,000 m) is a site of hydrothermal activity in which petroliferous materials is formed by thermal alteration of deposited planktonic and terrestrial organic matter. We investigated certain components of these naturally occurring hydrocarbons as potential carbon sources for a specific microflora at these deep-sea vent sites. Respiratory conversion of [1- 14 C]hexadecane and [1(4,5,8)- 14 C]naphthalene to 14 CO 2 was observed at 4 degree C and 25 degree C, and some was observed at 55 degree C, but none was observed at 80 degree C. Bacterial isolates were capable of growing on both substrates as the sole carbon source. All isolates were aerobic and mesophilic with respect to growth on hydrocarbons but also grew at low temperatures (4 to 5 degree C). These results correlate well with previous geochemical analyses, indicating microbial hydrocarbon degradation, and show that at least some of the thermally produced hydrocarbons at Guaymas Basin are significant carbon sources to vent microbiota

Catalytic conversion of carboxylic acids in bio-oil for liquid hydrocarbons production

International Nuclear Information System (INIS)

Wang, Shurong; Guo, Zuogang; Cai, Qinjie; Guo, Long

2012-01-01

Bio-oil must be upgraded to be suitable for use as a high-grade transport fuel. Crude bio-oil has a high content of carboxylic acids which can cause corrosion, and the high oxygen content of these acids also reduces the oil’s heating value. In this paper, acetic acid and propanoic acid were chosen as the model carboxylic acids in bio-oil. Their behavior in the production of liquid hydrocarbons during a catalytic conversion process was investigated in a micro-fixed bed reactor. The liquid organic phase from this catalytic conversion process mainly consisted of liquid hydrocarbons and phenol derivatives. Under the condition of low Liquid Hourly Space Velocity (LHSV), the liquid organic phase from acetic acid cracking had a selectivity of 22% for liquid hydrocarbons and a selectivity of 65% for phenol derivatives. The composition of the organic products changed considerably with the LHSV increasing to 3 h −1 . The selectivity for liquid hydrocarbons increased up to 52% while that for phenol derivatives decreased to 32%. Propanoic acid performed much better in producing liquid hydrocarbons than acetic acid. Its selectivity for liquid hydrocarbons was as high as 80% at LHSV = 3 h −1 . A mechanism for this catalytic conversion process was proposed according to the analysis of the components in the liquid organic phases. The pathways of the main compounds formation in the liquid organic phases were proposed, and the reason why liquid hydrocarbons were more effectively produced when using propanoic acid rather than acetic acid was also successfully explained. In addition, BET and SEM characterization were used to analyze the catalyst coke deposition. -- Graphical abstract: Display Omitted Highlights: ► High content of carboxylic acids in bio-oil causes its corrosiveness. ► Acetic acid and propanoic acid are two dominant acids in bio-oil. ► Liquid hydrocarbons were produced by cracking of these two dominant acids. ► A mechanism model was proposed to explain

Hydrogen sulfide release from dairy manure storages containing gypsum bedding

Science.gov (United States)

Recycled gypsum products can provide a cost-effective bedding alternative for dairy producers. Manufacturers report reduced odors, moisture and bacteria in the stall environment when compared to traditional bedding. Gypsum provides a sulfate source that can be converted to hydrogen sulfide under ana...

Methane and Benzene in Drinking-Water Wells Overlying the Eagle Ford, Fayetteville, and Haynesville Shale Hydrocarbon Production Areas.

Science.gov (United States)

McMahon, Peter B; Barlow, Jeannie R B; Engle, Mark A; Belitz, Kenneth; Ging, Patricia B; Hunt, Andrew G; Jurgens, Bryant C; Kharaka, Yousif K; Tollett, Roland W; Kresse, Timothy M

2017-06-20

Water wells (n = 116) overlying the Eagle Ford, Fayetteville, and Haynesville Shale hydrocarbon production areas were sampled for chemical, isotopic, and groundwater-age tracers to investigate the occurrence and sources of selected hydrocarbons in groundwater. Methane isotopes and hydrocarbon gas compositions indicate most of the methane in the wells was biogenic and produced by the CO 2 reduction pathway, not from thermogenic shale gas. Two samples contained methane from the fermentation pathway that could be associated with hydrocarbon degradation based on their co-occurrence with hydrocarbons such as ethylbenzene and butane. Benzene was detected at low concentrations (2500 years, indicating the benzene was from subsurface sources such as natural hydrocarbon migration or leaking hydrocarbon wells. One sample contained benzene that could be from a surface release associated with hydrocarbon production activities based on its age (10 ± 2.4 years) and proximity to hydrocarbon wells. Groundwater travel times inferred from the age-data indicate decades or longer may be needed to fully assess the effects of potential subsurface and surface releases of hydrocarbons on the wells.

Biological treatment process for removing petroleum hydrocarbons from oil field produced waters

Energy Technology Data Exchange (ETDEWEB)

Tellez, G.; Khandan, N.

1995-12-31

The feasibility of removing petroleum hydrocarbons from oil fields produced waters using biological treatment was evaluated under laboratory and field conditions. Based on previous laboratory studies, a field-scale prototype system was designed and operated over a period of four months. Two different sources of produced waters were tested in this field study under various continuous flow rates ranging from 375 1/D to 1,800 1/D. One source of produced water was an open storage pit; the other, a closed storage tank. The TDS concentrations of these sources exceeded 50,000 mg/l; total n-alkanes exceeded 100 mg/l; total petroleum hydrocarbons exceeded 125 mg/l; and total BTEX exceeded 3 mg/l. Removals of total n-alkanes, total petroleum hydrocarbons, and BTEX remained consistently high over 99%. During these tests, the energy costs averaged $0.20/bbl at 12 bbl/D.

Potential for biodegradation of polycyclic aromatic hydrocarbons by ...

African Journals Online (AJOL)

WiTT

2012-05-08

May 8, 2012 ... Full Length Research Paper. Biodegradation of ... organic compounds, including some organometallic ... is a major source of toxic PAHs that contributes signi- ficantly to ... microorganisms for bioremediation of hydrocarbon-.

Model-based evaluation of the use of polycyclic aromatic hydrocarbons molecular diagnostic ratios as a source identification tool

International Nuclear Information System (INIS)

Katsoyiannis, Athanasios; Breivik, Knut

2014-01-01

Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool. -- Highlights: • Model-based evaluation of the PAHs molecular diagnostic ratios efficiency. • Individual PAHs are characterized by different characteristic travel distances. • MDRs are proven to be a limited tool for source identification. • Use of MDRs for other environmental media is likely unfeasible. -- PAHs molecular diagnostic ratios which change greatly as a function of distance from the emitting source are improper for source identification purposes

Carbon coated (carbonous) catalyst in ebullated bed reactor for production of oxygenated chemicals from syngas/CO2

International Nuclear Information System (INIS)

Peizheng Zhou

2002-01-01

This report summarizes the work completed under DOE's Support of Advanced Fuel Research program, Contract No. DE-FG26-99FT40681. The contract period was October 2000 through September 2002. This R and D program investigated the modification of the mechanical strength of catalyst extrudates using Hydrocarbon Technologies, Inc. (HTI) carbon-coated catalyst technology so that the ebullated bed technology can be utilized to produce valuable oxygenated chemicals from syngas/CO 2 efficiently and economically. Exothermic chemical reactions benefit from the temperature control and freedom from catalyst fouling provided by the ebullated bed reactor technology. The carbon-coated extrudates prepared using these procedures had sufficient attrition resistance and surface area for use in ebullated bed operation. The low cost of carbon coating makes the carbon-coated catalysts highly competitive in the market of catalyst extrudates

Using multiple bed load measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers

Science.gov (United States)

Marquis, G. A.; Roy, A. G.

2012-02-01

This study examines bed load transport processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and bed load transport rates from bed load traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of bed load transport rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine sediments under very low gravel transport. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine sediment infiltration lead to the maintenance of a larger sediment framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on sediment transport and morphological changes in gravel-bed rivers.

Organic pollutants in the coastal environment off San Diego, California. 2: Petrogenic and biogenic sources of aliphatic hydrocarbons

International Nuclear Information System (INIS)

Tran, K.; Yu, C.C.; Zeng, E.Y.

1997-01-01

The results from the measurements of aliphatic hydrocarbons suggest that hydrocarbons suggest that hydrocarbons in the Point Loma Wastewater Treatment Plant (PLWTP) effluents are mainly petroleum derived; those in the Tijuana River runoff have largely originated from terrestrial plants with visible petroleum contamination; and those in the sea surface microlayer, sediment traps, and sediments at various coastal locations off San Diego have mostly resulted from biogenic contributions with enhanced microbial products in the summer season. Rainfall in the winter season appeared to amplify the inputs from terrestrial higher plants to the coastal areas. The PLWTP discharged approximately 3.85 metric tons of n-alkanes (C 10 -C 35 ) in 1994, well below the level (136 metric tons) estimated in 1979. The input of aliphatic hydrocarbons from the Tijuana River was about 0.101 metric tons in 1994. Diffusion, solubilization, evaporation, and microbial degradation seemed partially responsible for the difference in the concentrations and compositions of aliphatic hydrocarbons in different sample media, although the relative importance of each mechanism cannot be readily discerned from the available data. The results from analyses of aliphatic hydrocarbon compositional indices are generally consistent with those of polycyclic aromatic hydrocarbons

Condensation Mechanism of Hydrocarbon Field Formation.

Science.gov (United States)

Batalin, Oleg; Vafina, Nailya

2017-08-31

Petroleum geology explains how hydrocarbon fluids are generated, but there is a lack of understanding regarding how oil is expelled from source rocks and migrates to a reservoir. To clarify the process, the multi-layer Urengoy field in Western Siberia was investigated. Based on this example, we have identified an alternative mechanism of hydrocarbon field formation, in which oil and gas accumulations result from the phase separation of an upward hydrocarbon flow. There is evidence that the flow is generated by the gases released by secondary kerogen destruction. This study demonstrates that oil components are carried by the gas flow and that when the flow reaches a low-pressure zone, it condenses into a liquid with real oil properties. The transportation of oil components in the gas flow provides a natural explanation for the unresolved issues of petroleum geology concerning the migration process. The condensation mechanism can be considered as the main process of oil field formation.

Polystyrene plastic: a source and sink for polycyclic aromatic hydrocarbons in the marine environment.

Science.gov (United States)

Rochman, Chelsea M; Manzano, Carlos; Hentschel, Brian T; Simonich, Staci L Massey; Hoh, Eunha

2013-12-17

Polycyclic aromatic hydrocarbons (PAHs) on virgin polystyrene (PS) and PS marine debris led us to examine PS as a source and sink for PAHs in the marine environment. At two locations in San Diego Bay, we measured sorption of PAHs to PS pellets, sampling at 0, 1, 3, 6, 9, and 12 months. We detected 25 PAHs using a new analytical method with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. Several congeners were detected on samples before deployment. After deployment, some concentrations decreased (1,3-dimethylnaphthalene and 2,6-methylnaphthalene), while most increased [2-methylanthracene and all parent PAHs (PPAHs), except fluorene and fluoranthene], suggesting that PS debris is a source and sink for PAHs. When sorbed concentrations of PPAHs on PS are compared to the five most common polymers [polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), and polypropylene (PP)], PS sorbed greater concentrations than PP, PET, and PVC, similar to HDPE and LDPE. Most strikingly, at 0 months, PPAHs on PS ranged from 8 to 200 times greater than on PET, HDPE, PVC, LDPE, and PP. The combination of greater PAHs in virgin pellets and large sorption suggests that PS may pose a greater risk of exposure to PAHs upon ingestion.

Mathematical modelling on transport of petroleum hydrocarbons in ...

Indian Academy of Sciences (India)

Groundwater being the world's most extracted raw material, with withdrawal rates .... and analytical results, while Petroleum Hydro-Carbons (PHC) generally ... and pipeline ruptures form the major source of groundwater contamination by ...

Direct hydrocarbon fuel cells

Science.gov (United States)

Barnett, Scott A.; Lai, Tammy; Liu, Jiang

2010-05-04

The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

Monitoring in situ biodegradation of hydrocarbons by using stable carbon isotopes

International Nuclear Information System (INIS)

Aggarwal, P.K.; Hinchee, R.E.

1991-01-01

Spilled or leaked nonhalogenated petroleum hydrocarbons in the soil can generally be metabolized by indigenous, aerobic bacteria. In situ biological degradation of hydrocarbons may be accelerated by supplying inorganic nutrients and/or oxygen. Approaches to monitoring and verifying enhanced in situ biodegradation have included measurements of changes over time in the (a) concentration of hydrocarbons, (b) temperature, (c) number of hydrocarbon-degrading microorganisms, (d) ratio of fast-degrading hydrocarbons (e.g., pristanes or phytanes), and (e) metabolic intermediates. Measurements of oxygen consumption over time and elevated carbon dioxide concentrations in soil gas also have been used as indicators of hydrocarbon degradation. An alternative approach that may help substantiate biodegradation is to measure stable carbon isotope ratios in soil gas CO 2 . Stable carbon isotope ratio analysis is inexpensive and commercially available at many laboratories. Carbon dioxide produced by hydrocarbon degradation may be distinguished from that produced by other processes based on the carbon isotopic compositions characteristic of the source material and/or fractionation accompanying microbial metabolism. Here the authors demonstrate the applicability of the stable isotope technique for monitoring enhanced. aerobic biodegradation of hydrocarbons using data from three locations in the United States

Determination of the hydrocarbon-degrading metabolic capabilities of tropical bacterial isolates

Energy Technology Data Exchange (ETDEWEB)

Marquez-Rocha, F.J.; Olmos-Soto, J. [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, San Diego, CA (United States). Departamento de Biotecnologia Marina; Rosano-Hernandez, M.A.; Muriel-Garcia, M. [Instituto Mexicano del Petroleo, CD Carmen Camp (Mexico). Zona Marina/Tecnologia Ambiental

2005-01-01

Of more than 20 bacteria isolated from a tropical soil using minimal medium supplemented with hydrocarbons, 11 grew well on diesel as sole carbon source, and another 11 grew in the presence of polynuclear aromatic hydrocarbons (PAHs). Ten isolates were identified phenotypically as Pseudomonas sp. and eight as Bacillus sp. Gene sequences representing the catabolic genes (alkM, todM, ndoM, and xylM) and 16S rRNA gene sequences characteristic for Pseudomona and Bacillus were amplified by PCR, using DNA recovered from the supernatant of hydrocarbon-contaminated soil suspensions. Based on their rapid growth characteristics in the presence of hydrocarbons and the formation of PCR products for the catabolic genes alkM and ndoM six isolates were selected for biodegradation assays. After 30 days a mixed culture of two isolates achieved close to 70% hydrocarbon removal and apparent mineralization of 16% of the hydrocarbons present in the soil. Biodegradation rates varied from 275 to 387 mg hydrocarbon kg{sup -1} day{sup -1}. Several bacterial isolates obtained in this study have catabolic capabilities for the biodegradation of alkanes and aromatic hydrocarbons including PAHs. (author)

Isolation and identification of aromatic hydrocarbon degrading yeasts present in gasoline tanks of urbans vehicles

Directory of Open Access Journals (Sweden)

Nathalia Catalina Delgadillo-Ordoñez

2017-07-01

Full Text Available Yeast isolates were obtained from fuel tanks of vehicles in order to assess their potential use in the degradation of aromatic hydrocarbons. Growth assays were performed in minimum mineral medium using different aromatic hydrocarbons (benzene, toluene, naphthalene, phenanthrene, and pyrene as the sole carbon source. Isolates that showed growth in any of the tested polycyclic aromatic hydrocarbons were identified by Sanger sequencing of the ITS1 and ITS2 rDNA molecular markers. A total of 16 yeasts strains were isolated, and three showed remarkable growth in media with aromatic hydrocarbons as the sole carbon source. These strains belong to the genus Rhodotorula, and correspond to the species Rhodotorula calyptogenae (99,8% identity and Rhodotorula dairenensis (99,8% identity.  These strains grew in benzene, toluene, naphthalene, phenanthrene and pyrene. This study demonstrates for the first time that yeasts of the genus Rhodotorula inhabit pipelines and fuel tanks of vehicles and that remove   aromatic hydrocarbons that are environmental pollutants. Our results suggest that these yeasts are potential candidates for aromatic hydrocarbon degradation as part of bioremediation strategies.

Distribution and sources of the polycyclic aromatic hydrocarbons in the sediments of the Pearl River estuary, China.

Science.gov (United States)

Zhang, Jian-Dong; Wang, You-Shao; Cheng, Hao; Jiang, Zhao-Yu; Sun, Cui-Ci; Wu, Mei-Lin

2015-10-01

The Pearl River delta, one of the most prosperous economically region in China, has experienced significant contaminant inputs. However, the dynamics of pollutants in the Pearl River estuary and the adjacent coastal areas are still unclear at present. In the paper, distribution and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments of the Pearl River estuary. The total PAHs concentrations ranged from 126.08 to 3828.58 ng/g with a mean value of 563.52 ng/g, whereas the highest PAHs were observed in Guangzhou channel. Among the U.S. Environmental Protection Agency's 16 priority PAHs, PAHs with 3-4 rings exhibited relative higher levels. A positive relationship was found between PAHs and total organic carbon. The source analysis further showed that the major sources of PAHs in the Pearl River estuary were originated from the pyrolytic inputs, reflecting a mixed energy structure such as wood, coal and petroleum combustion. In summary, although PAHs in Lingding Bay and the adjacent coastal areas of the Pearl River estuary exhibited a relatively low pollution level, the relatively high pollution level of PAHs in Guangzhou channel will be attended.

Characteristics of atmospheric non-methane hydrocarbons during haze episode in Beijing, China.

Science.gov (United States)

Guo, Songjun; Tan, Jihua; Duan, Jingchun; Ma, Yongliang; Yang, Fumo; He, Kebin; Hao, Jimin

2012-12-01

This study firstly focused on non-methane hydrocarbons (NMHCs) during three successive days with haze episode (16-18 August 2006) in Beijing. Concentrations of alkanes, alkenes, aromatic hydrocarbons, and ethyne all peaked at traffic rush hour, implying vehicular emission; and alkanes also peaked at non-traffic rush hour in the daytime, implying additional source. Especially, alkanes and aromatics clearly showed higher levels in the nighttime than that in the daytime, implying their active photochemical reactions in the daytime. Correlation coefficients (R (2)) showed that propane, n-butane, i-butane, ethene, propene, and benzene correlated with ethyne (R (2) = 0.61-0.66), suggesting that their main source is vehicular emission; 2-methylpentane and n-hexane correlated with i-pentane (R (2) = 0.61-0.64), suggesting that gasoline evaporation is their main source; and ethylbezene, m-/p-xylene, and o-xylene correlated with toluene (R (2) = 0.60-0.79), suggesting that their main source is similar to that of toluene (e.g., solvent usage). The R (2) of ethyne, i-pentane, and toluene with total NMHCs were 0.58, 0.76, and 0.60, respectively, indicating that ambient hydrocarbons are associated with vehicular emission, gasoline evaporation, and solvent usage. The sources of other hydrocarbons (e.g., ethane) might be natural gas leakage, biogenic emission, or long-range transport of air pollutants. Measured higher mean B/T ratio (0.78 ± 0.27) was caused by the more intensive photochemical activity of toluene than benzene, still indicating the dominant emission from vehicles.

Evaluation of abundant hydrocarbon-generation depressions in the deepwater area of Qiongdongnan Basin, South China Sea

Institute of Scientific and Technical Information of China (English)

LIU Zhen; SUN Zhipeng; WANG Zisong; ZHANG Wei; LI Tingan; HE Weijun; LI Fengxia

2016-01-01

It has been confirmed that the key source rocks of Qiongdongnan Basin are associated with the Yacheng Formation, which was deposited in a transitional marine-continental environment. Because the distribution and evolution patterns of the source rocks in the major depressions are different, it is important to determine the most abundant hydrocarbon-generation depressions in terms of exploration effectiveness. Based on an analysis of organic matter characteristics of the source rocks, in combination with drilling data and seismic data, this paper establishes a model to evaluate the hydrocarbon-generation depressions in the deepwater area of Qiongdongnan Basin. First of all, by using the method of seismic-facies model analysis, the distribution of sedimentary facies was determined. Then, the sedimentary facies were correlated with the organic facies, and the distribution of organic facies was predicted. Meanwhile, the thickness of source rocks for all the depressions was calculated on the basis of a quantitative analysis of seismic velocity and lithology. The relationship between mudstone porosity and vitrinite reflectance (Ro) was used to predict the maturity of source rocks. Second, using the parameters such as thickness and maturity of source rocks, the quantity and intensity of gas generation for Yacheng and Lingshui Formations were calculated. Finally, in combination with the identified hydrocarbon resources, the quantity and intensity of gas generation were used as a guide to establish an evaluation standard for hydrocarbon-generation depressions, which was optimized for the main depressions in the Central Depression Belt. It is proposed that Lingshui, Ledong, Baodao and Changchang Depressions are the most abundant hydrocarbon depressions, whilst Songnan and Beijiao Depressions are rich hydrocarbon depressions. Such an evaluation procedure is beneficial to the next stage of exploration in the deep-water area of Qiongdongnan Basin.

Statistical evaluation of variables affecting occurrence of hydrocarbons in aquifers used for public supply, California

Science.gov (United States)

Landon, Matthew K.; Burton, Carmen A.; Davis, Tracy A.; Belitz, Kenneth; Johnson, Tyler D.

2014-01-01

The variables affecting the occurrence of hydrocarbons in aquifers used for public supply in California were assessed based on statistical evaluation of three large statewide datasets; gasoline oxygenates also were analyzed for comparison with hydrocarbons. Benzene is the most frequently detected (1.7%) compound among 17 hydrocarbons analyzed at generally low concentrations (median detected concentration 0.024 μg/l) in groundwater used for public supply in California; methyl tert-butyl ether (MTBE) is the most frequently detected (5.8%) compound among seven oxygenates analyzed (median detected concentration 0.1 μg/l). At aquifer depths used for public supply, hydrocarbons and MTBE rarely co-occur and are generally related to different variables; in shallower groundwater, co-occurrence is more frequent and there are similar relations to the density or proximity of potential sources. Benzene concentrations are most strongly correlated with reducing conditions, regardless of groundwater age and depth. Multiple lines of evidence indicate that benzene and other hydrocarbons detected in old, deep, and/or brackish groundwater result from geogenic sources of oil and gas. However, in recently recharged (since ~1950), generally shallower groundwater, higher concentrations and detection frequencies of benzene and hydrocarbons were associated with a greater proportion of commercial land use surrounding the well, likely reflecting effects of anthropogenic sources, particularly in combination with reducing conditions.

Investigation of Adsorbed Gases Content in Coal Beds in Bosnia and Herzegovina

Directory of Open Access Journals (Sweden)

Sadadinovic, J.

2008-09-01

Full Text Available Investigation of the gas fraction in coal beds in Bosnia & Herzegovina has been performed systematically since 1988. Gas in coal beds can be present in free or adsorbed form, and dissolved in water. Methods of investigation are based on the direct approach, according to which the gas fraction is determined in the undisturbed coal bed.The quantity of the adsorbed and free gas in the coal bed is directly proportional to the gas pressure. Dependence is hyperbolic. The quantity of the free gas in mining conditions is being determined by measurement of the desorption index (Δp2. The desorption index for the Srednjobosanski coal basin ranges to 1571 Pa, and the free gas pressure in this coal basin amounts up to 3.75 MPa. The desorption index for coal beds in “Kreka” and “Banoviće” coal basins has negative values, which means that the free gas fraction within the coal beds is negligible, while separation of adsorbed gases is diffuse. The free gas pressure in the mentioned coal basins is below 0.1 MPa. Adsorbed gases within the coal are connected by physical adsorption according to Langmuir’s isothermal adsorption curve. Langmuir’s quantities, for coal bed conditions, ranges as follows: am from 0.826 to 9.52 m3 t–1 pcs, and b from 6.65 10–3 to 0.247 MPa–1. Adsorbed gas within Miocene coal beds contains methane in amounts of 1.49 m3 t–1 čus CH4 andcarbon(IVoxide in amounts of 0.15 m3 t–1 čus CO2. Adsorbed gas within Pliocene coal beds, without methane, dominant is content of carbon(IVoxide.The investigation of the gas content in coal beds of BiH conducted in this article reveal that the coal beds primarily contain methane, while others hydrocarbons such as ethane, ethene, propane, propene and butane are present sporadically in fraction below φ/10–6. Based on the investigation results conducted in this article, simple mathematical forms were obtained for quick calculation of the free gas quantity by measurement of the

Lacustrine Environment Reservoir Properties on Sandstone Minerals and Hydrocarbon Content: A Case Study on Doba Basin, Southern Chad

Science.gov (United States)

Sumery, N. F. Mohd; Lo, S. Z.; Salim, A. M. A.

2017-10-01

The contribution of lacustrine environment as the hydrocarbon reservoir has been widely known. However, despite its growing importance, the lacustrine petroleum geology has received far less attention than marine due to its sedimentological complexity. This study therefore aims in developing an understanding of the unique aspects of lacustrine reservoirs which eventually impacts the future exploration decisions. Hydrocarbon production in Doba Basin, particularly the northern boundary, for instance, has not yet succeeded due to the unawareness of its depositional environment. The drilling results show that the problems were due to the: radioactive sand and waxy oil/formation damage, which all are related to the lacustrine depositional environment. Detailed study of geological and petrophysical integration on wireline logs and petrographic thin sections analysis of this environment helps in distinguishing reservoir and non-reservoir areas and determining the possible mechanism causing the failed DST results. The interpretations show that the correlation of all types> of logs and rho matrix analysis are capable in identifying sand and shale bed despite of the radioactive sand present. The failure of DST results were due to the presence of arkose in sand and waxy oil in reservoir bed. This had been confirmed by the petrographic thin section analysis where the arkose has mineral twinning effect indicate feldspar and waxy oil showing bright colour under fluorescent light. Understanding these special lacustrine environment characteristics and features will lead to a better interpretation of hydrocarbon prospectivity for future exploration.

Natural hydrocarbon seeps observation with underwater gliders and UV fluorescence sensor

Science.gov (United States)

Rochet, V.

2016-02-01

Hydrocarbons may leak to the near-surface from subsurface accumulations, from mature source rock, or by buoyancy along major cross-strata routes. The presence of migrating near-surface hydrocarbons can provide strong evidence for the presence of a working petroleum system, as well as valuable information on source, maturity, and migration pathways. Detection and characterization of hydrocarbons in the water column may then help to de-risk hydrocarbon plays at a very preliminary stage of an exploration program. In order to detect hydrocarbons in the water column, an underwater glider survey was conducted in an offshore frontier area. Driven by buoyancy variation, underwater gliders enable collecting data autonomously along the water column for weeks to months. Underwater gliders are regularly piloted from shore by satellite telemetry and do not require a surface supervising vessel resulting in substantial operational costs savings. The data compiled, over 700m depth of the water column, included temperature, salinity, pressure, dissolved oxygen and hydrocarbon components (phenanthrene and naphthalene) measured by "MINIFLUO" sensors to particularly target representative crude oil compounds Two gliders were deployed at sea, one from coast in shallow water and the other one offshore on the survey area. Both accurately squared the survey area following pre-defined lines and cross lines. Data files were transmitted by satellite telemetry in near real time during the performance of the mission for real time observations and appropriate re-positioning of the gliders. Using rechargeable underwater gliders increased reliability reducing the risk of leakage and associated logistics during operation at sea. Despite strong evidences of seabed seepages such as pockmarks, faults, etc, over the area of interest, no hydrocarbon indices were detected in the water column, which was confirmed later by seabed sample analysis. The use of glider platforms for hydrocarbon detection has

Can sediments at hydrocarbon seep sites represent a source for marine bioavailable iron? — A case study from the South China Sea

Science.gov (United States)

Li, N.; Feng, D.; Chen, D.

2017-12-01

Niu Li1, Dong Feng1,2, and Duofu Chen2,31CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. 2Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China. 3Hadal Science and Technology Research Center, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China. Iron is an essential micronutrient and commonly considered to be one of the key-limiting factors for biological productivity in many ocean regions. Seafloor Fe supply should be most efficient in suboxic conditions. Recent studies shown that widely spread anoxic environments can develop in hydrocarbon seep sediment and local bottom water, owing to the occurrence of aerobic and/or anaerobic methane oxidation. Under this condition, the iron in sediment can be reduced to dissolved Fe2+ in the ocean. However, questions remain about whether the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean, and the control factor for the transformation of iron in the sediment remains largely unexplored. For a number of hydrocarbon seeps from the northern and southern South China Sea, the iron speciation, pyrite sulfur isotope, and iron isotope, as well as the major and trace elements are used to constrain the intensity of cold seep, and its impact on transformation of iron in sediment. Samples from both areas show sediment iron lost during the high methane flux conditions, owing to the suboxic conditions cause by aerobic methane oxidation. On the other hand, high sediment iron content accompanied by high sulfur content can be seen during the conditions of high methane flux without the occurrence of aerobic methane oxidation, which is possible ascribed to the anaerobic methane oxidation and the release of iron through seep activity. This study reveals the transformation of iron in the sediment is closely related to the

[Characteristics and sources of particulate polycyclic aromatic hydrocarbons (PAHs) during haze period in Guangzhou].

Science.gov (United States)

Duan, Jing-Chun; Tan, Ji-Hua; Sheng, Guo-Ying; Fu, Jia-Mo

2009-06-15

PM10 (particulates matter with aerodynamic diameter Guangzhou city between March 2002 and June 2003. Polycyclic aromatic hydrocarbons (PAHs) were studied during haze and non-haze periods in both summer and winter. PAHs pollution was serious in haze period compared with that in non-haze period, especially in winter. Compared with non-haze period, Phe, Ant, Flu, Pyr, BaA, Chr, IcdP, DahA and BghiP were more abundant in haze period in summer, and BaF, BeP, BaP, Pery, IcdP, DahA and BghiP were more abundant in haze period in winter. The BEQ values were 3.5 ng x m(-3), 3.35 ng x m(-3), 1.43 ng x m(-3) and 13.0 ng x m(-3) in non-haze in summer, in haze in summer, in non-haze in winter and in haze in winter, respectively. The BEQ values in non-haze in summer, in haze in summer and in non-haze in winter in Guangzhou (average: 2.76 ng x m(-3)) were relatively low in Chinese cities, and comparable with oversea cities. However, the BEQ value in haze in winter was relatively high in Chinese cities. It indicated that haze in winter would impair human health seriously. The diagnostic ratios suggested gasoline and diesel vehicle emission were main sources of PAHs in summer, and diesel vehicle and coal combustion emission were main sources of PAHs in winter; PAHs may come from both local sources and long-range transportation in non-haze in winter.

Polycyclic aromatic hydrocarbons in soils of the central Tibetan Plateau, China: Distribution, sources, transport and contribution in global cycling

International Nuclear Information System (INIS)

Yuan, Guo-Li; Wu, Li-Juan; Sun, Yong; Li, Jun; Li, Jing-Chao; Wang, Gen-Hou

2015-01-01

Forty-four soil samples were collected across the central Tibetan Plateau (CTP) at altitudes between 3711 m and 5352 m, and their polycyclic aromatic hydrocarbons (PAHs) contents were measured to be from 0.43 to 26.66 ng/g. The main sources of PAHs were identified for each of four sub-areas, and their concentrations in soils were determined to be mainly influenced by local sources. Along a 600 km sampling trajectory from Lhasa, which served as the biggest local source, the concentrations of PAHs decreased logarithmically with increasing distances from the source. Meanwhile, the fractional proportions of PAHs were observed to change logarithmically according to the transport distances. Conclusively, PAHs from local sources were transported within the CTP and dominated PAHs concentrations in the soils, but few of them were transported outside the CTP. In global cycling, the soils in the CTP mainly serve as background and a “sink” for PAHs. - Highlights: • Main sources of PAHs were identified for each of four sub-areas in CTP. • Local sources dominated PAHs in soils but rarely transported outside CTP. • The PAHs in soils changed logarithmically according to the distances from source. • It is first revealed how the local PAH sources influenced PAHs in the soils of CTP. - Local sources dominated PAHs concentrations in the soils of CTP but rarely transported outside, and PAHs in soils changed logarithmically according to the transported distances

Spatial distribution and sources of heavy metals and petroleum hydrocarbon in the sand flats of Shuangtaizi Estuary, Bohai Sea of China.

Science.gov (United States)

Yang, Xiaolong; Yuan, Xiutang; Zhang, Anguo; Mao, Yuze; Li, Qiang; Zong, Humin; Wang, Lijun; Li, Xiaodong

2015-06-15

The concentrations of heavy metals and petroleum hydrocarbons (PHCs) in surface sediments were investigated in the sand flats of Shuangtaizi Estuary, Bohai Sea of China in May, 2013. Ecological risk assessment indicated that most heavy metals cause low ecological risk to the estuarine environment, with the exception of Cd and Hg (considerable and moderate risk, respectively). Principal component analysis in combination with correlation analysis among heavy metals, PHCs and geological factors (e.g., granularity) was used to identify possible sources of pollutants in Shuangtaizi Estuary. Results showed that the main pollution sources of the area come from anthropogenic factors, such as sewage discharge and oil exploitation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of the vadose zone above a shallow aquifer contaminated with gas condensate hydrocarbons

International Nuclear Information System (INIS)

Sublette, K.; Duncan, K.; Thoma, G.; Todd, T.

2002-01-01

A gas production site in the Denver Basin near Ft. Lupton, Colorado has leaked gas condensate hydrocarbons from an underground concrete tank used to store produced water. The leak has contaminated a shallow aquifer. Although the source of pollution has been removed, a plume of hydrocarbon contamination still remains for nearly 46 m from the original source. An extensive monitoring program was conducted in 1993 of the groundwater and saturated sediments. The objective was to determine if intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurred at the site at a rate that would support remediation. Geochemical indicators of hydrogen biodegradation by microorganisms in the saturated zone included oxygen depletion, increased alkalinity, sulfate depletion, methane production and Fe2+ production associated with hydrogen contamination. The presence of sulfate-reducing bacteria and methanogens was also much higher in the contaminated sediments. Degraded hydrocarbon metabolites were found in contaminated groundwater. An extensive characterization of the vadose zone was conducted in which the vadose zone was sample in increments of 15 cm from the surface to the water table at contaminated and non contaminated sites. The samples were tested for individual C3+ hydrocarbons, methane, CO2, total organic carbon, total inorganic carbon, and total petroleum hydrocarbons. The vadose zone consisted of an active and aerobic bioreactor fueled by condensate hydrocarbons transported into the unsaturated zone by evaporation of hydrocarbons at the water table. It was concluded that the unsaturated zone makes an important contribution to the natural attenuation of gas condensate hydrocarbons in the area. 17 refs., 2 tabs., 28 figs

Seasonal effect and source apportionment of polycyclic aromatic hydrocarbons in PM2.5

Science.gov (United States)

Khan, Md Firoz; Latif, Mohd Talib; Lim, Chee Hou; Amil, Norhaniza; Jaafar, Shoffian Amin; Dominick, Doreena; Mohd Nadzir, Mohd Shahrul; Sahani, Mazrura; Tahir, Norhayati Mohd

2015-04-01

This study aims to investigate distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) bound to fine particulate matter (PM2.5) captured in a semi-urban area in Malaysia during different seasons, and to assess their health risks. PM2.5 samples were collected using a high volume air sampler on quartz filter paper at a flow rate of 1 m3 min-1 for 24 h. PAHs on the filter paper were extracted with dichloromethane (DCM) using an ultrasonic centrifuge solid-phase extraction method and measured by gas chromatography-mass spectroscopy. The results showed that the range of PAHs concentrations in the study period was between 0.21 and 12.08 ng m-3. The concentrations of PAHs were higher during the south-west monsoon (0.21-12.08 ng m-3) compared to the north-east monsoon (0.68-3.80 ng m-3). The high molecular weight (HMW) PAHs (≥5 ring) are significantly prominent (>70%) compared to the low molecular weight (LMW) PAHs (≤4 ring) in PM2.5. The Spearman correlation indicates that the LMW and HMW PAHs correlate strongly among themselves. The diagnostic ratios (DRs) of I[c]P/I[c]P + BgP and B[a]P/B[g]P suggest that the HMW PAHs originated from fuel combustion sources. The source apportionment analysis of PAHs was resolved using DRs-positive matrix factorization (PMF)-multiple linear regression (MLR). The main sources identified were (a) gasoline combustion (65%), (b) diesel and heavy oil combustion (19%) and (c) natural gas and coal burning (15%). The health risk evaluation, by means of the lifetime lung cancer risk (LLCR), showed no potential carcinogenic risk from the airborne BaPeq (which represents total PAHs at the present study area in Malaysia). The seasonal LLCR showed that the carcinogenic risk of total PAHs were two fold higher during south-westerly monsoon compared to north-easterly monsoon.

The presence of hydrocarbons in southeast Norway

DEFF Research Database (Denmark)

Hanken, Niels Martin; Hansen, Malene Dolberg; Kresten Nielsen, Jesper

Hydrocarbons, mostly found as solid pyrobitumen, are known from more than 30 localities in southeast Norway. They occur as inclusions in a wide range of "reservoir rocks" spanning from Permo-Carboniferous breccias to veins (vein quartz and calcite veins) in Precambrian granites, gneisses and amph......Hydrocarbons, mostly found as solid pyrobitumen, are known from more than 30 localities in southeast Norway. They occur as inclusions in a wide range of "reservoir rocks" spanning from Permo-Carboniferous breccias to veins (vein quartz and calcite veins) in Precambrian granites, gneisses......, indicating that Alum Shale was the most important source rock. Petrographic investigations combined with stable isotope analyses (d13C and d18O) of the cement containing pyrobitumen indicate two phases of hydrocarbon migration. The first phase probably took place in Upper Silurian to Lower Devonian time......, when the Alum Shale entered the oil window. These hydrocarbons are mostly found as pyrobitumen in primary voids and calcite cemented veins in Cambro-Silurian sedimentary deposits. The second phase is probably of Late Carboniferous/Permian age and was due to the increased heat flow during the formation...

Benthic Community Structure and Sediment Geochemical Properties at Hydrocarbon Seeps Along the Continental Slope of the Western North Atlantic

Science.gov (United States)

Demopoulos, A. W.; Bourque, J. R.; Brooke, S.

2015-12-01

Hydrocarbon seeps support distinct benthic communities capable of utilizing reduced chemical compounds for nutrition. In recent years, methane seepage has been increasingly documented along the continental slope of the U.S. Atlantic margin. In 2012 and 2013, two seeps were investigated in this region: a shallow site near Baltimore Canyon (410-450 m) and a deep site near Norfolk Canyon (1600 m). Both sites contain extensive mussel beds and microbial mats. Sediment cores and grab samples were collected to quantify the abundance, diversity, and community structure of benthic macrofauna (>300 mm) in relationship to the associated sediment environment (organic carbon and nitrogen, stable isotopes 13C and 15N, grain size, and depth) of mussel beds, mats, and slope habitats. Macrofaunal densities in microbial mats were four times greater than those present in mussel beds and slope sediments. Macrofaunal communities were distinctly different both between depths and among habitat types. Specifically, microbial mat sediments were dominated by the annelid families Dorvilleidae, Capitellidae, and Tubificidae, while mussel habitats had higher proportions of crustaceans. Diversity was lower in Baltimore microbial mat habitats, but higher in mussel and slope sediments compared to Norfolk seep habitats found at deeper depths. Multivariate statistical analysis identified sediment carbon:nitrogen (C:N) ratios and 13C values as important variables for structuring the macrofaunal communities. Higher C:N ratios were present within microbial mat habitats and depleted 13C values occurred in sediments adjacent to mussel beds found in Norfolk Canyon seeps. Differences in the quality and source of organic matter present in the seep habitats are known to be important drivers in macrofaunal community structure and associated food webs. The multivariate analysis provides new insight into the relative importance of the seep sediment quality in supporting dense macrofaunal communities compared

Seasonal Variations and Sources of Airborne Polycyclic Aromatic Hydrocarbons (PAHs in Chengdu, China

Directory of Open Access Journals (Sweden)

Ju Yang

2018-02-01

Full Text Available The concentrations of polycyclic aromatic hydrocarbons (PAHs in the air of Chengdu, a southwest city of China, were determined from March 2015 to February 2016. Here, two diagnostic ratios (DR were determined and a principal component analysis/multiple linear regression (PCA/MLR analysis was performed to identify the sources of PAHs during the four seasons. The gaseous and particle phase samples were analyzed separately. The sampled air had a gas-to particle ratio of 4.21, and between 18.7% and 31.3% of the total detected PAHs were found in the particulate phase. The total concentration of all 16-PAHs combined (gas + particles varied from 176.94 in summer to 458.95 ng·m−3 in winter, with a mean of 300.35 ± 176.6 ng·m−3. In the gas phase, phenanthrene(Phe was found at the highest concentrations in all four seasons, while benzo[b]fluoranthene(BbF and (in winter chrysene(Chr were the highest in the particle phase. The DR of Fluroanthene (Flua/(Flua + Pyrene (Pyr was higher in the gas phase than in the particle phase, while the Indeno[1,2,3-cd]pyrene(IcdP/(IcdP + Benzo[ghi]perylene (BghiP ratio was more variable in the gas than that in the particle phase. The main sources for both phases were a mixture of liquid fossil fuel combustion and the burning of biomass and coal, with clear seasonal variation. Principal Component Analysis/Multiple Linear Regression (PCA/MLR analysis identified the main PAH sources as coal burning (52% with motor vehicle exhaust and coke (48% in spring; coal (52%, coke (21%, and motor vehicle exhaust (27% in summer; coal (47%, vehicle exhaust (34%, and coke (19% in autumn; and coal (58% and vehicle exhaust (42% in winter.

Risk analysis associated with petroleum hydrocarbons: is everything running smoothly?

International Nuclear Information System (INIS)

Morin, D.

1999-01-01

Petroleum products represent one of the main sources of environmental contamination, and these products are complex, composed of several hundred individual hydrocarbons. The evaluation of the risks associated with petroleum products is often limited by certain specific parameters such as benzene. The petroleum hydrocarbons running from C(10) to C(50) are not often integrated in an analysis of the toxological risks since the toxological characterization of a complex mixture of hydrocarbons is difficult to carry out. There exist in the United States two approaches that were developed recently that allow the integration of various hydrocarbons comprising a mixture. In this presentation, two of these approaches are described and compared. An overview of these approaches related to Canadian regulatory bodies is included, and a case study completes the account. The two approaches that are most well known in this area are: 1) that of the Massachusetts Dept. of Environmental Protection, and 2) that of the Total Petroleum Hydrocarbon Criteria Working Group. The integration of petroleum hydrocarbons in a quantitative evaluation of their toxological risk is possible by present methods. This integration allows a reduction in the uncertainty associated with the use of an integrating parameter in the case of these petroleum hydrocarbons in the C(10) to the C(50) range

Jet-Fuel Range Hydrocarbons from Biomass-Derived Sorbitol over Ni-HZSM-5/SBA-15 Catalyst

Directory of Open Access Journals (Sweden)

Yujing Weng

2015-12-01

Full Text Available Aromatics and cyclic-hydrocarbons are the significant components of jet fuel with high energy-density. However, conventional technologies for bio-fuel production cannot produce these products without further aromatization and isomerization. In this work, renewable liquid fuel with high content of aromatics and cyclic-hydrocarbons was obtained through aqueous catalytic conversion of biomass sorbitol over Ni-HZSM-5/SBA-15 catalyst. Texture characteristics of the catalyst were determined by physisorption of N2, which indicated its bimodal pore structures were microporous (HZSM-5, pore width: 0.56 nm and mesoporous (SBA-15, pore width: 8 nm. The surface acidity included weak and strong acid sites, predominantly Lewis type, and was further confirmed by the NH3-TPD and Py-IR analysis. The catalytic performances were tested in a fixed-bed reactor under the conditions of 593 K, WHSV of 0.75 h−1, GHSV of 2500 h−1 and 4.0 MPa of hydrogen pressure, whereby oil yield of 40.4 wt. % with aromatics and cyclic-hydrocarbons content of 80.0% was obtained.

Mineral oil hydrocarbons in food - a review.

Science.gov (United States)

Grob, Koni

2018-06-12

Work on mineral oil hydrocarbons (MOH) contaminating food is reviewed up to about 2010, when the subject received broad publicity. It covers the period of the main discoveries and elimination or reduction of the dominant sources: release agents used in industrial bakeries, spraying of rice, additions to animal feed, contamination of edible oils from various sources and migration from paperboard packaging. In most cases highly refined ("white") oils were involved, but also technical oils, e.g. from the environment, and more or less crude oil fractions from jute and sisal bags. There were numerous unexpected sources, and there might still be more of those. The exposure of the consumers to MOH must have been markedly reduced in the meantime. Environmental influx may have become dominant, particularly when taking into account that these MOH go through several degradation processes which might enrich the species resisting metabolic elimination. Major gaps are in the systematic investigation of sources and the largely unavoidable levels from environmental contamination, but also in the toxicological evaluation of the various types of hydrocarbons. A regulation is overdue that avoids the present discrepancy between the low tolerance to MOH perceived as contaminants and the very high legal limits for some applications - the MOH are largely the same.

Bioremediation of Petroleum Hydrocarbon Contaminated Sites

Energy Technology Data Exchange (ETDEWEB)

Fallgren, Paul

2009-03-30

Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of

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

Sources and deposition of polycyclic aromatic hydrocarbons to western US national parks

Science.gov (United States)

Seasonal snowpack, lichens, and lake sediment cores were collected from fourteen lake catchments in eight western U.S. National Parks and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) to determine their current and historical deposition, as well as to identify thei...

Sources of hydrocarbons in sediments of the Mandovi estuary and the Marmugoa harbour, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Harji, R.R.; Yvenat, A.; Bhosle, N.B.

anthropogenic hydrocarbon inputs. Mar Environ Res 1992;33:223-253. Stout SA, Uhler AD, McCarthy KJ, Emsbo-Mattingly S. Chemical fingerprinting of hydrocarbons. In: Murphy BL, Morrison R (Eds.), Introduction to Environmental Forensics. Academic Press, Boston...

Preliminary Geospatial Analysis of Arctic Ocean Hydrocarbon Resources

Energy Technology Data Exchange (ETDEWEB)

Long, Philip E.; Wurstner, Signe K.; Sullivan, E. C.; Schaef, Herbert T.; Bradley, Donald J.

2008-10-01

Ice coverage of the Arctic Ocean is predicted to become thinner and to cover less area with time. The combination of more ice-free waters for exploration and navigation, along with increasing demand for hydrocarbons and improvements in technologies for the discovery and exploitation of new hydrocarbon resources have focused attention on the hydrocarbon potential of the Arctic Basin and its margins. The purpose of this document is to 1) summarize results of a review of published hydrocarbon resources in the Arctic, including both conventional oil and gas and methane hydrates and 2) develop a set of digital maps of the hydrocarbon potential of the Arctic Ocean. These maps can be combined with predictions of ice-free areas to enable estimates of the likely regions and sequence of hydrocarbon production development in the Arctic. In this report, conventional oil and gas resources are explicitly linked with potential gas hydrate resources. This has not been attempted previously and is particularly powerful as the likelihood of gas production from marine gas hydrates increases. Available or planned infrastructure, such as pipelines, combined with the geospatial distribution of hydrocarbons is a very strong determinant of the temporal-spatial development of Arctic hydrocarbon resources. Significant unknowns decrease the certainty of predictions for development of hydrocarbon resources. These include: 1) Areas in the Russian Arctic that are poorly mapped, 2) Disputed ownership: primarily the Lomonosov Ridge, 3) Lack of detailed information on gas hydrate distribution, and 4) Technical risk associated with the ability to extract methane gas from gas hydrates. Logistics may control areas of exploration more than hydrocarbon potential. Accessibility, established ownership, and leasing of exploration blocks may trump quality of source rock, reservoir, and size of target. With this in mind, the main areas that are likely to be explored first are the Bering Strait and Chukchi

Emission and source characterization of monoaromatic hydrocarbons from coke production

Energy Technology Data Exchange (ETDEWEB)

He, Q.S.; Wang, X.M.; Sheng, G.Y.; Fu, J.M. [Chinese Academy of Sciences, Guangzhou (China). State Key Laboratory of Organic Geochemistry

2005-09-15

Monoaromatic hydrocarbons (MAHs) from indigenous and industrial coking processes are studied in Shanxi province. They are sampled on the top of coke ovens and in the chimneys using stainless steel canister and determined by GC/MSD after preconcentration with liquid nitrogen. Benzene, toluene and xylene are the main components among MAHs emitted from coking processes. Benzene and the total MAHs concentrations were as high as 3421.0 microg/m3 and 4 865.9 microg/m3 in the air from indigenous coking, 548.7 microg/m3 and 1 054.8 microg/m3 in the oventop air from industrial coking, and 1 376.4 microg/m3 and 1 819.4 microg/m3 in stack gas from industrial coking, respectively. The MAHs concentrations vary greatly during the indigenous coking process, which in the prophase (from firing to 10 days) is obviously higher than in the anaphase (10 days to quenching the coke). In industrial coking the MAHs in the oventop air are highest when charging the coal and next when transferring the hot coke, but in stack gas they are highest when charging coal and lowest when transferring the coke. Benzene, toluene, ethylbenzene and xylene (BTEX) in industrial coking samples show good linearity, indicating that MAHs in industrial coking might come predominantly from coal pyrolysis; but BTEX distribute dispersedly in indigenous coking samples, indicating that its emission might be affected by many factors. In all samples BTEX ratios especially high B/E ratio, is unique among MAHs sources, and might be helpful to characterize pollution from coking.

[Emission and source characterization of monoaromatic hydrocarbons from coke production].

Science.gov (United States)

He, Qiu-Sheng; Wang, Xin-Ming; Sheng, Guo-Ying; Fu, Jia-Mo

2005-09-01

Monoaromatic hydrocarbons (MAHs) from indigenous and industrial coking processes are studied in Shanxi province. They are sampled on the top of coke ovens and in the chimneys using stainless steel canister and determined by GC/MSD after preconcentration with liquid nitrogen. Benzene, toluene and xylene are the main components among MAHs emitted from coking processes. Benzene and the total MAHs concentrations were as high as 3421.0 microg/m3 and 4 865.9 microg/m3 in the air from indigenous coking, 548.7 microg/m3 and 1 054.8 microg/m3 in the oventop air from industrial coking, and 1 376.4 microg/m3 and 1 819.4 microg/m3 in stack gas from industrial coking, respectively. The MAHs concentrations vary greatly during the indigenous coking process, which in the prophase (from firing to 10 days) is obviously higher than in the anaphase (10 days to quenching the coke). In industrial coking the MAHs in the oventop air are highest when charging the coal and next when transferring the hot coke, but in stack gas they are highest when charging coal and lowest when transferring the coke. Benzene, toluene, ethylbenzene and xylene (BTEX) in industrial coking samples show good linearity, indicating that MAHs in industrial coking might come predominantly from coal pyrolysis; but BTEX distribute dispersedly in indigenous coking samples, indicating that its emission might be affected by many factors. In all samples BTEX ratios especially high B/E ratio, is unique among MAHs sources, and might be helpful to characterize pollution from coking.

Hydrocarbon-degrading sulfate-reducing bacteria in marine hydrocarbon seep sediments

OpenAIRE

Kleindienst, Sara

2012-01-01

Microorganisms are key players in our biosphere because of their ability to degrade various organic compounds including a wide range of hydrocarbons. At marine hydrocarbon seeps, more than 90% of sulfate reduction (SR) is potentially coupled to non-methane hydrocarbon oxidation. Several hydrocarbon-degrading sulfate-reducing bacteria (SRB) were enriched or isolated from marine sediments. However, in situ active SRB remained largely unknown. In the present thesis, the global distribution and a...

Study utilization of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuels

Science.gov (United States)

Hendrianie, Nuniek; Juliastuti, Sri Rachmania; Ar-rosyidah, Fanny Husna; Rochman, Hilal Abdur

2017-05-01

Nowadays the existence of energy sources of oil and was limited. Therefore, it was important to searching for new innovations of renewable energy sources by utilizing the waste into a source of energy. On the other hand, the process of extractable petroleum hydrocarbons biodegradation generated sludge that had calorific value and untapped. Because of the need for alternative sources of energy innovation with the concept of zero waste and the fuel potential from extractable petroleum hydrocarbons biodegradation waste, so it was necessary to study the use of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuel. In addition, sawdust is a waste that had a great quantities and also had a high calorific value to be mixed with extractable petroleum hydrocarbons biodegradation waste. The purpose of this study was to determine the characteristics of the extractable petroleum hydrocarbons biodegradation waste and to determine the potential and a combination of a mixture of extractable petroleum hydrocarbons biodegradation waste and sawdust which has the best calorific value. The variables of this study was the composition of the waste and sawdust as follows 1:1; 1:3; and 3:1 (mass of sawdust : mass of waste) and time of sawdust carbonization was 10, 15 and 20 minutes. Sawdust was carbonized to get the high heating value. The characteristic of main material and fuel analysis performed with proximate analysis. While the calorific value analysis was performed with a bomb calorimeter. From the research, it was known that extractable petroleum hydrocarbons biodegradation waste had a moisture content of 3.06%; volatile matter 19.98%; ash content of 0.56%; fixed carbon content of 76.4% and a calorific value of 717 cal/gram. And a mixture that had the highest calorific value (4286.5 cal/gram) achieved in comparison sawdust : waste (3:1) by carbonization of sawdust for 20 minutes.

Concentrations, sources and spatial distribution of polycyclic aromatic hydrocarbons in soils from Beijing, Tianjin and surrounding areas, North China

International Nuclear Information System (INIS)

Wang Wentao; Massey Simonich, Staci L.; Xue Miao; Zhao Jingyu; Zhang Na; Wang Rong; Cao Jun; Tao Shu

2010-01-01

The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote-rural village-urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources. - The concentration, profiles and possible sources of PAHs in Beijing, Tianjin and surrounding area soils were studied and related to population density and gross domestic product (GDP).

Ancient glaciations and hydrocarbon accumulations in North Africa and the Middle East

Science.gov (United States)

Le Heron, Daniel Paul; Craig, Jonathan; Etienne, James L.

2009-04-01

Palaeozoic source rock across the region. Existing models do not adequately explain the temporal and spatial development of anoxia, and hence of black shale/deglacial source rocks. The origins of a palaeotopography previously invoked as the primary driver for this anoxia is allied to a complex configuration of palaeo-ice stream pathways, "underfilled" tunnel valley incisions, glaciotectonic deformation structures and re-activation of older crustal structures during rebound. A putative link with the development of Silurian glaciation in northern Chad is suggested. Silurian glaciation appears to have been restricted to the southern Al Kufrah Basin in the eastern part of North Africa, and was associated with the deposition of boulder beds. Equivalent deposits are lacking in shallow marine deposits in neighbouring outcrop belts. Evidence for Carboniferous-Permian glaciation is tentative in the eastern Sahara (SW Egypt) but well established on the Arabian Peninsula in Oman and more recently in Saudi Arabia. Pennsylvanian-Sakmarian times saw repeated glaciation-deglaciation cycles affecting the region, over a timeframe of about 20 Myr. Repeated phases of deglaciation produced a complex stratigraphy consisting, in part, of structureless sandstone intervals up to 50 m thick. Some of these sandstone intervals are major hydrocarbon intervals in the Omani salt basins. Whilst studies of the Hirnantian glaciation can provide lessons on the causes of large-scale variability within Carboniferous-Permian glaciogenic reservoirs, additional factors also influenced their geometry. These include the effects of topography produced during Hercynian orogenesis and the mobilisation and dissolution of the Precambrian Ara Salt. Deglacial or interglacial lacustrine shale, with abundant palynomorphs, is also important. Whilst both Cryogenian intervals and the Hirnantian-Rhuddanian deglaciation resulted in the deposition of glaciomarine deposits, Carboniferous-Permian deglaciation likely occurred within

Investigations of material balance and the formation of metabolites on white rot in clamps in soil loaded with polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Zarth, M.

1993-01-01

One examines from a concrete case to what extent the potential danger of white rot in bio-beds caused by polycyclic aromatic hydrocarbons (PAH's) is reduced. The potential danger is mainly determined by the remainder of the PAH's. The remainder paths to be considered (micro-biological decomposition, transport and abiotic processes) are shown. (orig.) [de

Source characterization and exposure modeling of gas-phase polycyclic aromatic hydrocarbon (PAH) concentrations in Southern California

Science.gov (United States)

Masri, Shahir; Li, Lianfa; Dang, Andy; Chung, Judith H.; Chen, Jiu-Chiuan; Fan, Zhi-Hua (Tina); Wu, Jun

2018-03-01

Airborne exposures to polycyclic aromatic hydrocarbons (PAHs) are associated with adverse health outcomes. Because personal air measurements of PAHs are labor intensive and costly, spatial PAH exposure models are useful for epidemiological studies. However, few studies provide adequate spatial coverage to reflect intra-urban variability of ambient PAHs. In this study, we collected 39-40 weekly gas-phase PAH samples in southern California twice in summer and twice in winter, 2009, in order to characterize PAH source contributions and develop spatial models that can estimate gas-phase PAH concentrations at a high resolution. A spatial mixed regression model was constructed, including such variables as roadway, traffic, land-use, vegetation index, commercial cooking facilities, meteorology, and population density. Cross validation of the model resulted in an R2 of 0.66 for summer and 0.77 for winter. Results showed higher total PAH concentrations in winter. Pyrogenic sources, such as fossil fuels and diesel exhaust, were the most dominant contributors to total PAHs. PAH sources varied by season, with a higher fossil fuel and wood burning contribution in winter. Spatial autocorrelation accounted for a substantial amount of the variance in total PAH concentrations for both winter (56%) and summer (19%). In summer, other key variables explaining the variance included meteorological factors (9%), population density (15%), and roadway length (21%). In winter, the variance was also explained by traffic density (16%). In this study, source characterization confirmed the dominance of traffic and other fossil fuel sources to total measured gas-phase PAH concentrations while a spatial exposure model identified key predictors of PAH concentrations. Gas-phase PAH source characterization and exposure estimation is of high utility to epidemiologist and policy makers interested in understanding the health impacts of gas-phase PAHs and strategies to reduce emissions.

Production of hydrogen via conversion of hydrocarbons using a microwave plasma

International Nuclear Information System (INIS)

Jasinski, Mariusz; Dors, Miroslaw; Nowakowska, Helena; Mizeraczyk, Jerzy; Nichipor, Gerietta V

2011-01-01

In this paper, results of hydrogen production from hydrocarbons in an atmospheric pressure microwave plasma are presented. As sources of hydrogen, both methane CH 4 and tetrafluoroethane C 2 H 2 F 4 were tested. A new waveguide-based nozzleless cylinder-type microwave plasma source was used to convert hydrocarbons into hydrogen. The processed gaseous hydrocarbons were introduced into the plasma by four gas ducts which formed a swirl flow in the plasma reactor. The absorbed microwave power was up to 5 kW. The gas flow rate was up to 212 L min -1 . The hydrogen mass yield rate and the corresponding energetic hydrogen mass yield were up to 866 g[H 2 ] h -1 and 577 g [H 2 ] kWh -1 of microwave energy absorbed by the plasma, respectively. These parameters are better than our previous results when nitrogen was used as a swirl gas and much better than those typical for other plasma methods of hydrogen production (electron beam, gliding arc, plasmatron).

Source identification of hydrocarbon contaminants and their transportation over the Zonguldak shelf, Turkish Black Sea

Science.gov (United States)

Unlu, S.; Alpar, B.

2009-04-01

Under great anthropogenic pressure due to the substantial freshwater input from the surrounding industrial and agricultural areas, especially central and middle-Eastern Europe, the Black Sea basin is ranked among the most ecologically threatened water bodies of the world. Oil levels are unacceptable in many coastal areas perilously close to polluted harbors and many river mouths; the places presenting the highest levels of bio-diversity and having a high socio-economic importance due to human use of coastal resources. There are about sixty sources of pollution which resulted in "hot spots" having disastrous impacts on sensitive marine and coastal areas and needing immediate priorities for action. Beyond such land-based sources, trans-boundary pollution sources from Black Sea riparian countries, heavy maritime traffic, particularly involving petroleum transports and fishing boats, and the improper disposal of ballast and bilge waters and solid waste are also important marine sources of pollution. Found in fossil fuels such as Polycyclic Aromatic Hydrocarbons are generated by incomplete combustion of organic matter. In order to estimate their distribution in sediment and their sources, they were monitored from the bottom samples offshore the Zonguldak industry region, one of the most polluted spots in the Turkish Black Sea. There the budget of pollutants via rivers is not precisely known due to an evident lack of data on chemical and granulometric composition of the river runoff and their fluxes. Therefore the marine sediments, essential components of marine ecosystems, are very important in our estimating the degree of the damage given to the ecosystem by such inputs. Realization of the sources and transport of these contaminants will be a critical tool for future management of the Zonguldak industry region and its watershed. The sea bottom in study area is composed of mainly sand and silt mixtures with small amount of clay. Geochemical analyses have shown that oil

Assessment of polycyclic aromatic hydrocarbons (PAHs) pollution in soil of suburban areas in Tianjin, China.

Science.gov (United States)

Lv, Jungang; Shi, Rongguang; Cai, Yanming; Liu, Yong

2010-07-01

Soil contamination with polycyclic aromatic hydrocarbons is an increasing problem and has aroused more and more concern in many countries, including China. In this study, representative soil samples (n = 87) of suburban areas in Tianjin (Xiqing, Dongli, Jinnan, Beichen) were evaluated for 16 polycyclic aromatic hydrocarbons. Surface soil samples were air-dried and sieved. Microwave assisted extraction was used for polycyclic aromatic hydrocarbons preparation prior to analysis with gas chromatography-mass spectrometry. The total concentrations of tested polycyclic aromatic hydrocarbons in Xiqing, Dongli, Jinnan, Beichen ranged in 58.5-2,748.3, 36.1-6,734.7, 58.5-4,502.5, 29.7-852.5 ng/g and the averages of total concentration of polycyclic aromatic hydrocarbons were 600.5, 933.6, 640.8, 257.3 ng/g, respectively. Spatial variation of polycyclic aromatic hydrocarbons in soil was illustrated; Pollution status and comparison to other cities were also investigated. Serious polycyclic aromatic hydrocarbons soil pollution was found in Dongli district, on the contrary, Bap in most sites in Beichen did not exceed relative standards and most sites in Beichen should be classified as non-contaminated soil. Principal component analysis was used to identify the possible sources of different districts. It turned out that coal combustion still was the most important sources in three districts except Beichen. Coking, traffic, cooking, biomass combustion also accounted for polycyclic aromatic hydrocarbons pollution to certain extent in different districts. These data can be further used to assess the health risk associated with soils polluted with polycyclic aromatic hydrocarbons and help local government find proper way to reduce polycyclic aromatic hydrocarbons pollution in soils.

Catalytic pyrolysis of woody biomass in a fluidized bed reactor: influence of the zeolite structure

Energy Technology Data Exchange (ETDEWEB)

A. Aho; N. Kumar; K. Eranen; T. Salmi; M. Hupa; D.Yu. Murzin [Aabo Akademi University, Aabo/Turku (Finland). Process Chemistry Centre, Laboratory of Industrial Chemistry and Reaction Engineering

2008-09-15

Catalytic pyrolysis of biomass from pine wood was carried out in a fluidized bed reactor at 450{sup o}C. Different structures of acidic zeolite catalysts were used as bed material in the reactor. Proton forms of Beta, Y, ZSM-5, and Mordenite were tested as catalysts in the pyrolysis of pine, while quartz sand was used as a reference material in the non-catalytic pyrolysis experiments. The yield of the pyrolysis product phases was only slightly influenced by the structures, at the same time the chemical composition of the bio-oil was dependent on the structure of acidic zeolite catalysts. Ketones and phenols were the dominating groups of compounds in the bio-oil. The formation of ketones was higher over ZSM-5 and the amount of acids and alcohols lower than over the other bed materials tested. Mordenite and quartz sand produced smaller quantities of polyaromatic hydrocarbons than the other materials tested. It was possible to successfully regenerate the spent zeolites without changing the structure of the zeolite. 12 refs., 9 figs., 5 tabs.

Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

Science.gov (United States)

Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana M.; Fachel, Jandyra Maria Guimarães; Leal, Karen Alam; Garcia, Karine de Oliveira; Wiegand, Flavio

2012-11-01

The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5-10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5-10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA.

Infant's bed climate and bedding in the Japanese home.

Science.gov (United States)

Nakamura Ikeda, Rie; Fukai, Kiyoko; Okamoto Mizuno, Kazue

2012-06-01

to assess the bed climate of infants in their homes in Japan. descriptive, exploratory, non-experimental research design. the data were collected at the participants' homes under normal circumstances. nineteen healthy infants between the ages of two and five months. Their mothers, who joined a parenting class organised by a maternity clinic in Okayama, Japan, consented to participate in this study. we visited the infants' homes and interviewed their mothers concerning the types and use of bedding. The temperature and relative humidity of the bed climate at the back and foot of the bedding, and in the room were measured every minute for four consecutive days. Differences among the bed climates measured during three seasons (spring, summer, and autumn) were assessed by one-way analysis of variance. The bed temperature was higher for infants than for adults. No significant difference in temperature was noted among the three seasons. The bed temperature was about 36.0°C when waterproof sheets and futon mattresses for children or adult were used. The average relative humidity of the bed climate at the back was highest in summer, followed by that in spring and autumn; the differences were significant. The use of waterproof sheets and futon mattresses for children in summer increased the relative humidity to 80% or more. The use of infant beds, sunoko drainboards, and cotton futon mattresses in summer was effective in reducing the bed humidity. these results suggest that nurse-midwives should advise the parents on comfortable bed climates for their infants, as well as how to select and use bedding for them. Copyright © 2010 Elsevier Ltd. All rights reserved.

The origin of high hydrocarbon groundwater in shallow Triassic aquifer in Northwest Guizhou, China.

Science.gov (United States)

Liu, Shan; Qi, Shihua; Luo, Zhaohui; Liu, Fangzhi; Ding, Yang; Huang, Huanfang; Chen, Zhihua; Cheng, Shenggao

2018-02-01

Original high hydrocarbon groundwater represents a kind of groundwater in which hydrocarbon concentration exceeds 0.05 mg/L. The original high hydrocarbon will significantly reduce the environment capacity of hydrocarbon and lead environmental problems. For the past 5 years, we have carried out for a long-term monitoring of groundwater in shallow Triassic aquifer in Northwest Guizhou, China. We found the concentration of petroleum hydrocarbon was always above 0.05 mg/L. The low-level anthropogenic contamination cannot produce high hydrocarbon groundwater in the area. By using hydrocarbon potential, geochemistry and biomarker characteristic in rocks and shallow groundwater, we carried out a comprehensive study in Dalongjing (DLJ) groundwater system to determine the hydrocarbon source. We found a simplex hydrogeology setting, high-level water-rock-hydrocarbon interaction and obviously original hydrocarbon groundwater in DLJ system. The concentration of petroleum hydrocarbon in shallow aquifer was found to increase with the strong water-rock interaction. Higher hydrocarbon potential was found in the upper of Guanling formation (T 2 g 3 ) and upper of Yongningzhen formation (T 1 yn 4 ). Heavily saturated carbon was observed from shallow groundwater, which presented similar distribution to those from rocks, especially from the deeper groundwater. These results indicated that the high concentrations of original hydrocarbon in groundwater could be due to the hydrocarbon release from corrosion and extraction out of strata over time.

Combined in-situ and ex-situ bioremediation of petroleum hydrocarbon contaminated soils by closed-loop soil vapor extraction and air injection

International Nuclear Information System (INIS)

Hu, S.S.; Buckler, M.J.

1993-01-01

Treatment and restoration of petroleum hydrocarbon contaminated soils at a bulk petroleum above-ground storage tank (AST) site in Michigan is being conducted through in-situ and ex-situ closed-loop soil vapor extraction (SVE), soil vapor treatment, and treated air injection (AI) processes. The soil vapor extraction process applies a vacuum through the petroleum hydrocarbon affected soils in the ex-situ bio-remediation pile (bio-pile) and along the perimeter of excavated area (in-situ area) to remove the volatile or light petroleum hydrocarbons. This process also draws ambient air into the ex-situ bio-pile and in-situ vadose zone soil along the perimeter of excavated area to enhance biodegradation of light and heavy petroleum hydrocarbons in the soil. The extracted soil vapor is treated using a custom-designed air bio-remediation filter (bio-filter) to degrade the petroleum hydrocarbon compounds in the soil vapor extraction air streams. The treated air is then injected into a flush grade soil bed in the backfill area to perform final polishing of the air stream, and to form a closed-loop air flow with the soil vapor extraction perforated pipes along the perimeter of the excavated area

Numerical modeling of straw combustion in a fixed bed

DEFF Research Database (Denmark)

Zhou, Haosheng; Jensen, Anker; Glarborg, Peter

2005-01-01

. The straw combustion processes include moisture evaporation, straw pyrolysis, gas combustion, and char combustion. The model provides detailed information of the structure of the ignition flame front. Simulated gas species concentrations at the bed surface, ignition flame front rate, and bed temperature......Straw is being used as main renewable energy source in grate boilers in Denmark. For optimizing operating conditions and design parameters, a one-dimensional unsteady heterogeneous mathematical model has been developed and experiments have been carried out for straw combustion in a fixed bed...... are in good agreement with measurements at different operating conditions such as primary air-flow rate, pre-heating of the primary air, oxygen concentration, moisture content in straw, and bulk density of the straw in the fixed bed. A parametric study indicates that the effective heat conductivity, straw...

Synthetic aperture controlled source electromagnetics

NARCIS (Netherlands)

Fan, Y.; Snieder, R.; Slob, E.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.

2010-01-01

Controlled?source electromagnetics (CSEM) has been used as a de?risking tool in the hydrocarbon exploration industry. Although there have been successful applications of CSEM, this technique is still not widely used in the industry because the limited types of hydrocarbon reservoirs CSEM can detect.

Sources and patterns of polycyclic aromatic hydrocarbons pollution in kitchen air, China.

Science.gov (United States)

Zhu, Lizhong; Wang, Jing

2003-02-01

Twelve polycyclic aromatic hydrocarbons, multi-ringed compounds known to be carcinogenic in air of six domestic kitchens and four commercial kitchens of China were measured in 1999-2000. The mean concentration of total PAHs in commercial kitchens was 17 microg/m3, consisting mainly of 3- and 4-ring PAHs, and 7.6 microg/m3 in domestic kitchens, where 2- and 3-ring PAHs were predominant, especially naphthalene. The BaP levels in domestic kitchens were 0.0061-0.024 microg/m3 and 0.15- 0.44 microg/m3 in commercial kitchens. Conventional Chinese cooking methods were responsible for such heavy PAHs pollution. The comparative study for PAH levels in air during three different cooking practices: boiling, broiling and frying were conducted. It was found that boiling produced the least levels of PAHs. For fish, a low-fat food, frying it produced a larger amount of PAHs compared to broiling practice, except pyrene and anthracene. In commercial kitchens, PAHs came from two sources, cooking practice and oil-fumes, however the cooking practice had a more predominant contribution to PAHs in commercial kitchen air. In domestic kitchens, except for cooking practice and oil-fumes, there were other PAHs sources, such as smoking and other human activities in the domestic houses, where 3-4 ring PAHs mainly came from cooking practice. Naphthalene (NA, 2-ring PAHs) was the most predominant kind, mostly resulting from the evaporation of mothball containing a large quantity of NA, used to prevent clothes against moth. A fingerprint of oil-fumes was the abundance of 3-ring PAHs. Heating at the same temperature, the PAHs concentrations in different oil-fumes were lard > soybean oil > rape-seed oil. An increase in cooking temperature increased the levels of PAHs, especially acenaphthene.

Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico.

Directory of Open Access Journals (Sweden)

Isabel C Romero

Full Text Available The Deepwater Horizon (DWH spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000-1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC, aliphatic, polycyclic aromatic hydrocarbon (PAHs, and biomarker (hopanes, steranes, diasteranes compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1 sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material, and 2 advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related variability in the DeSoto Canyon, NE of the DWH wellhead.

Sedimentological analysis and bed thickness statistics from a Carboniferous deep-water channel-levee complex: Myall Trough, SE Australia

Science.gov (United States)

Palozzi, Jason; Pantopoulos, George; Maravelis, Angelos G.; Nordsvan, Adam; Zelilidis, Avraam

2018-02-01

This investigation presents an outcrop-based integrated study of internal division analysis and statistical treatment of turbidite bed thickness applied to a Carboniferous deep-water channel-levee complex in the Myall Trough, southeast Australia. Turbidite beds of the studied succession are characterized by a range of sedimentary structures grouped into two main associations, a thick-bedded and a thin-bedded one, that reflect channel-fill and overbank/levee deposits, respectively. Three vertically stacked channel-levee cycles have been identified. Results of statistical analysis of bed thickness, grain-size and internal division patterns applied on the studied channel-levee succession, indicate that turbidite bed thickness data seem to be well characterized by a bimodal lognormal distribution, which is possibly reflecting the difference between deposition from lower-density flows (in a levee/overbank setting) and very high-density flows (in a channel fill setting). Power law and exponential distributions were observed to hold only for the thick-bedded parts of the succession and cannot characterize the whole bed thickness range of the studied sediments. The succession also exhibits non-random clustering of bed thickness and grain-size measurements. The studied sediments are also characterized by the presence of statistically detected fining-upward sandstone packets. A novel quantitative approach (change-point analysis) is proposed for the detection of those packets. Markov permutation statistics also revealed the existence of order in the alternation of internal divisions in the succession expressed by an optimal internal division cycle reflecting two main types of gravity flow events deposited within both thick-bedded conglomeratic and thin-bedded sandstone associations. The analytical methods presented in this study can be used as additional tools for quantitative analysis and recognition of depositional environments in hydrocarbon-bearing research of ancient

Tracking channel bed resiliency in forested mountain catchments using high temporal resolution channel bed movement

Science.gov (United States)

Martin, Sarah E.; Conklin, Martha H.

2018-01-01

This study uses continuous-recording load cell pressure sensors in four, high-elevation (1500-1800 m), Sierra Nevada headwater streams to collect high-temporal-resolution, bedload-movement data for investigating the channel bed movement patterns within these streams for water years 2012-2014. Data show an annual pattern where channel bed material in the thalweg starts to build up in early fall, peaks around peak snow melt, and scours back to baseline levels during hydrograph drawdown and base flow. This pattern is punctuated by disturbance and recovery of channel bed material associated with short-term storm events. A conceptual model, linking sediment sources at the channel margins to patterns of channel bed fill and scour in the thalweg, is proposed building on the results of Martin et al. (2014). The material in the thalweg represents a balance between sediment supply from the channel margins and sporadic, conveyor-belt-like downstream transport in the thalweg. The conceptual model highlights not only the importance of production and transport rates but also that seasonal connectedness between the margins and thalweg is a key sediment control, determining the accumulation rate of sediment stores at the margins and the redistribution of sediment from margins to thalweg that feeds the conveyor belt. Disturbance and recovery cycles are observed at multiple temporal scales; but long term, the channel beds are stable, suggesting that the beds act as short-term storage for sediment but are in equilibrium interannually. The feasibility of use for these sensors in forested mountain stream environments is tested. Despite a high failure rate (50%), load cell pressure sensors show potential for high-temporal-resolution bedload measurements, allowing for the collection of channel bed movement data to move beyond time-integrated change measurements - where many of the subtleties of bedload movement patterns may be missed - to continuous and/or real-time measurements. This

Modelling post-depositional transport of PAHs in aquatic bed sediments using CoReTranS

Energy Technology Data Exchange (ETDEWEB)

Go, Jason [Imperial College London, London (United Kingdom). Dept. of Earth Science and Engineering; Stegemann, Julia A. [Imperial College London, London (United Kingdom). Dept. of Civil, Environmental and Geomatic Engineering

2012-12-15

Purpose: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent contaminants in aquatic bed sediments. A better understanding of their in-bed fate and transport is therefore key in minimising the risk to the environment over time through various remediation and monitoring strategies. Since ecological effects and risks are related to contaminant concentrations, this study developed CoReTranS, a predictive model that simulates one-dimensional organic contaminant reaction and transport in bed sediments. Materials and methods: CoReTranS was benchmarked against analytical solutions of simplified reactive transport models and validated using a published study of marsh sediments contaminated with petroleum-derived hydrocarbons from Wild Harbour, West Falmouth, MA, USA. Results and discussion: The CoReTranS model effectively predicted the vertical distribution of PAHs in the Wild Harbour sediments as confirmed by the modelling results from the published study. The CoReTranS model was also used to interpret results from a published study of PAH-contaminated fjord sediments from Kitimat Arm in British Columbia, Canada. Specific insights into the post-depositional fate and transport of selected PAHs in the Kitimat fjord sediments were obtained by comparing the measured concentration-depth profiles with the numerical results from the CoReTranS model. Key parameters such as effective diffusivity of contaminants and burial velocities of sediment particles were shown to possibly account for the predicted concentrations-depth profiles in the Kitimat fjord sediments. Conclusions: As demonstrated, CoReTranS can simulate reactive transport models in order to predict PAH concentration profiles in porewater under site-specific conditions. The information derived from the use of the CoReTranS model highlighted practical application of such information by engineers to site-specific risk assessment and remediation. (orig.)

Aliphatic hydrocarbons in surface sediments from South China Sea off Kuching Division, Sarawak

International Nuclear Information System (INIS)

Hafidz Yusoff; Zaini Assim; Samsur Mohamad

2012-01-01

Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/ MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 μg/ g to 1466.1 μg/ g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C 31 / C 19 and C 29 / C 31 indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world. (author)

[Pollution characteristics and sources of polycyclic aromatic hydrocarbons in urban rivers of Wenzhou city].

Science.gov (United States)

Zhou, Jie-Cheng; Chen, Zhen-Lou; Bi, Chun-Juan; Lü, Jin-Gang; Xu, Shi-Yuan; Pan, Qi

2012-12-01

Concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) in water and surface sediments collected from the urban rivers of Wenzhou city in spring and summer were measured by GC-MS. The results showed that the total PAHs concentrations in water and sediments of the studied rivers varied in ranges of 146.74-3 047.89 ng x L(-1) and 21.01-11 990.48 ng x g(-1), respectively. Higher concentrations occurred in spring. The low and middle rings of 2-4-ring were dominant in both water and sediments, but the concentrations of 5-ring and 6-ring PAHs in sediments were relatively higher than those in water. The EBaP values of PAHs in water of the studied rivers in spring and summer were 1.69-51.95 ng x L(-1) and 0-3.03 ng x L(-1), respectively. Eighty percent of water samples in spring surpassed the limits of BaP in surface water of China. The concentrations of sigma PAHs in the sediments both in spring and summer were lower than the ERM value, but part of the components of PAHs had values higher than the ERM, suggesting possible toxic effect on living organisms. Based on the PAHs molecule ratios and principal component analysis, a mixed PAHs source of petroleum and combustion in water and sediments was diagnosed, while sediments showed a greater proportion of combustion sources.

Towards minimizing measurement uncertainty in total petroleum hydrocarbon determination by GC-FID

Energy Technology Data Exchange (ETDEWEB)

Saari, E.

2009-07-01

Despite tightened environmental legislation, spillages of petroleum products remain a serious problem worldwide. The environmental impacts of these spillages are always severe and reliable methods for the identification and quantitative determination of petroleum hydrocarbons in environmental samples are therefore needed. Great improvements in the definition and analysis of total petroleum hydrocarbons (TPH) were finally introduced by international organizations for standardization in 2004. This brought some coherence to the determination and, nowadays, most laboratories seem to employ ISO/DIS 16703:2004, ISO 9377-2:2000 and CEN prEN 14039:2004:E draft international standards for analysing TPH in soil. The implementation of these methods, however, usually fails because the reliability of petroleum hydrocarbon determination has proved to be poor.This thesis describes the assessment of measurement uncertainty for TPH determination in soil. Chemometric methods were used to both estimate the main uncertainty sources and identify the most significant factors affecting these uncertainty sources. The method used for the determinations was based on gas chromatography utilizing flame ionization detection (GC-FID).Chemometric methodology applied in estimating measurement uncertainty for TPH determination showed that the measurement uncertainty is in actual fact dominated by the analytical uncertainty. Within the specific concentration range studied, the analytical uncertainty accounted for as much as 68-80% of the measurement uncertainty. The robustness of the analytical method used for petroleum hydrocarbon determination was then studied in more detail. A two-level Plackett-Burman design and a D-optimal design were utilized to assess the main analytical uncertainty sources of the sample treatment and GC determination procedures. It was also found that the matrix-induced systematic error may also significantly reduce the reliability of petroleum hydrocarbon determination

Surface geochemical data evaluation and integration with geophysical observations for hydrocarbon prospecting, Tapti graben, Deccan Syneclise, India

Directory of Open Access Journals (Sweden)

T. Satish Kumar

2014-05-01

Full Text Available The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable areas identified by integrated geophysical studies. The compositional and isotopic signatures of adsorbed gaseous hydrocarbons (methane through butane were used as surface indicators of petroleum micro-seepages. An analysis of 75 near-surface soil-gas samples was carried out for light hydrocarbons (C1–C4 and their carbon isotopes from the western part of Tapti graben, Deccan Syneclise, India. The geochemical results reveal sites or clusters of sites containing anomalously high concentrations of light hydrocarbon gases. High concentrations of adsorbed thermogenic methane (C1 = 518 ppb and ethane plus higher hydrocarbons (ΣC2+ = 977 ppb were observed. Statistical analysis shows that samples from 13% of the samples contain anomalously high concentrations of light hydrocarbons in the soil-gas constituents. This seepage suggests largest magnitude of soil gas anomalies might be generated/source from Mesozoic sedimentary rocks, beneath Deccan Traps. The carbon isotopic composition of methane, ethane and propane ranges are from −22.5‰ to −30.2‰ PDB, −18.0‰ to 27.1‰ PDB and 16.9‰–32.1‰ PDB respectively, which are in thermogenic source. Surface soil sample represents the intersection of a migration conduit from the deep subsurface to the surface connected to sub-trappean Mesozoic sedimentary rocks. Prominent hydrocarbon concentrations were associated with dykes, lineaments and presented on thinner basaltic cover in the study area

Field desorption mass spectroscopy monitoring of changes in hydrocarbon type composition during petroleum biodegradation

International Nuclear Information System (INIS)

Huesemann, M.H.

1995-01-01

A comprehensive petroleum hydrocarbon characterization procedure involving group type separation, boiling point distribution, and hydrocarbon typing by field desorption mass spectroscopy (FDMS) has been developed to quantify changes in hydrocarbon type composition during bioremediation of petroleum-contaminated soils. FDMS is able to quantify the concentration of hundreds of specific hydrocarbon types based on their respective hydrogen deficiency (z-number) and molecular weight (carbon number). Analytical results from two bioremediation experiments involving soil contaminated with crude oil and motor oil indicate that alkanes and two-ring saturates (naphthenes) were readily biodegradable. In addition, low-molecular-weight hydrocarbons generally were biodegraded to a larger extent than those of high molecular weight. More importantly, it was found that the extent of biodegradation of specific hydrocarbon types was comparable between treatments and appeared to be unaffected by the petroleum contaminant source, soil type, or experimental conditions. It was therefore concluded that in these studies the extent of total petroleum hydrocarbon (TPH) biodegradation is primarily affected by the molecular composition of the petroleum hydrocarbons present in the contaminated soil

Bed Bugs

Science.gov (United States)

Prevent, identify, and treat bed bug infestations using EPA’s step-by-step guides, based on IPM principles. Find pesticides approved for bed bug control, check out the information clearinghouse, and dispel bed bug myths.

Mobile sources of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH: Results of samples collected in a roadway tunnel

International Nuclear Information System (INIS)

Benner, B.A. Jr.; Gordon, G.E.; Wise, S.A.

1987-01-01

A recent review article emphasized the need for further characterizations of the carbonaceous fraction of mobile source emissions, particularly with the impending removal of lead alkyl octane boosters and bromine-containing lead scavengers from regular leaded gasolines. The lead and bromine emitted from the combustion of these fuels have been used as tracers of mobile source emissions for a number of years. Single vehicle emission studies have shed light on the relationship between engine operating parameters and the chemical characteristics of the emissions but they are not suitable for use in source apportionment studies which require emission data from a large number of different vehicles. Air particulate samples collected near a busy highway or in a roadway tunnel would be more appropriate for use in estimating the mobile source contribution of organic compounds to a region. Suspended particle samples collected in a heavily-travelled roadway tunnel (Baltimore Harbor Tunnel, Baltimore, Maryland) were characterized for polycyclic aromatic hydrocarbons (PAH) and some nitro-PAH by gas and liquid chromatographic techniques. These samples included those collected on Teflon filters and on glass fiber filters for investigating any differences in samples collected on an inert (Teflon) and more reactive (glass-fiber) medium. All samples collected on Teflon were backed-up with polyurethane foam plugs (PUF) which trapped any inherent vapor-phase PAH as well as any compounds ''blown-off'' the particles during collection

Petroleum hydrocarbons in a water-sediment system from Yellow River estuary and adjacent coastal area, China: Distribution pattern, risk assessment and sources.

Science.gov (United States)

Wang, Min; Wang, Chuanyuan; Li, Yuanwei

2017-09-15

Aliphatic hydrocarbons (AHs), biomarker and polycyclic aromatic hydrocarbons (PAHs) concentrations of surface water and sediment samples collected from Yellow River Estuary and adjacent coastal area in China were measured to determine their spatial distributions, analyze their sources and evaluate the ecological risk of PAHs in the water-sediment system. The spatial distributions of n-alkane in sediments are mainly controlled by the mixing inputs of terrigenous and marine components. In comparison with AHs, the total concentrations of Σ16PAHs in surface sediments from a transect of the offshore area were noticeably higher than that of the riverine and estuary areas. Additionally, the AHs and total PAHs concentrations all indicated an overall pattern of a seaward decrease. The PAHs concentrations during the dry season (mainly in the form of dissolved phase) were higher than that of PAHs (mainly dissolved phase and particulate phase form) in the flooding season. In comparison with global concentration levels of PAHs, the level of PAHs in suspended particulate matter and sediments from the Yellow River Estuary was lower than those from other countries, while the concentration of PAHs in the dissolved phase were in the middle range. Petroleum contamination, mainly from oil exploration and discharge of pollutants from rivers, was the main source of n-alkanes. The PAHs in the river were mostly of petrogenic origin, while those in the estuarial and marine areas originated mainly from pyrogenic sources. The results of the toxicology assessment suggested that the PAHs in sediments from Yellow River Estuary and adjacent coastal area exhibited a low potential eco-toxicological contamination level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural attenuation of diesel aliphatic hydrocarbons in contaminated agricultural soil

International Nuclear Information System (INIS)

Serrano, Antonio; Gallego, Mercedes; Gonzalez, Jose Luis; Tejada, Manuel

2008-01-01

A diesel fuel spill at a concentration of 1 L m -2 soil was simulated on a 12 m 2 plot of agricultural land, and natural attenuation of aliphatic hydrocarbons was monitored over a period of 400 days following the spill after which the aliphatic hydrocarbon concentrations were found to be below the legal contamination threshold for soil. The main fraction of these compounds (95%) remained at the surface layer (0-10 cm). Shortly after the spill (viz. between days 0 and 18), evaporation was the main origin of the dramatic decrease in pollutant concentrations in the soil. Thereafter, soil microorganisms used aliphatic hydrocarbons as sources of carbon and energy, as confirmed by the degradation ratios found. Soil quality indicators, soil microbial biomass and dehydrogenase activity, regained their original levels about 200 days after the spill. - The effect of aliphatic hydrocarbons contamination on soil quality was monitored over a period of 400 days after a Diesel fuel spill

Analysis of ORC (Organic Rankine Cycle) systems with pure hydrocarbons and mixtures of hydrocarbon and retardant for engine waste heat recovery

International Nuclear Information System (INIS)

Song, Jian; Gu, Chun-wei

2015-01-01

The Organic Rankine Cycle (ORC) has been demonstrated to be a promising technology for the recovery of engine waste heat. Systems with hydrocarbons as the working fluids exhibit good thermal performance. However, the flammability of hydrocarbons limits their practical applications because of safety concerns. This paper examines the potential of using mixtures of a hydrocarbon and a retardant in an ORC system for engine waste heat recovery. Refrigerants R141b and R11 are selected as the retardants and blended with the hydrocarbons to form zeotropic mixtures. The flammability is suppressed, and in addition, zeotropic mixtures provide better temperature matches with the heat source and sink, which reduces the exergy loss within the heat exchange processes, thereby increasing the cycle efficiency. Energetic and exergetic analysis of ORC systems with pure hydrocarbons and with mixtures of a hydrocarbon and a retardant are conducted and compared. The net power output and the second law efficiency are chosen as the evaluation criteria to select the suitable working fluid compositions and to define the optimal set of thermodynamic parameters. The simulation results reveal that the ORC system with cyclohexane/R141b (0.5/0.5) is optimal for this engine waste heat recovery case, thereby increasing the net power output of the system by 13.3% compared to pure cyclohexane. - Highlights: • ORC with zeotropic mixtures for engine waste heat recovery is discussed. • Energetic and exergetic analysis of ORC system are conducted. • Optimal mixture working fluid composition is identified. • Greater utilization of jacket water and lower irreversible loss are important.

Source apportionment of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH) associated to airborne PM10 by a PMF model.

Science.gov (United States)

Callén, M S; Iturmendi, A; López, J M; Mastral, A M

2014-02-01

In order to perform a study of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene equivalent (BaP-eq) concentration was calculated and modelled by a receptor model based on positive matrix factorization (PMF). Nineteen PAH associated to airborne PM10 of Zaragoza, Spain, were quantified during the sampling period 2001-2009 and used as potential variables by the PMF model. Afterwards, multiple linear regression analysis was used to quantify the potential sources of BaP-eq. Five sources were obtained as the optimal solution and vehicular emission was identified as the main carcinogenic source (35 %) followed by heavy-duty vehicles (28 %), light-oil combustion (18 %), natural gas (10 %) and coal combustion (9 %). Two of the most prevailing directions contributing to this carcinogenic character were the NE and N directions associated with a highway, industrial parks and a paper factory. The lifetime lung cancer risk exceeded the unit risk of 8.7 x 10(-5) per ng/m(3) BaP in both winter and autumn seasons and the most contributing source was the vehicular emission factor becoming an important issue in control strategies.

Identification of emission sources of particle-bound polycyclic aromatic hydrocarbons in the vicinity of the industrial zone of the city of Novi Sad

OpenAIRE

Jovčić Nataša S.; Radonić Jelena R.; Turk-Sekulić Maja M.; Vojinović-Miloradov Mirjana B.; Popov Srđan B.

2013-01-01

Data on polycyclic aromatic hydrocarbons (PAHs) in ambient air accessed at selected locations in the vicinity of the industrial zone of the city of Novi Sad, Serbia, have been presented and analyzed in order to determine seasonal and spatial variations and to identify emission sources of particle-bound PAHs. Previous studies have demonstrated that the major contributors of PAHs in urban areas are the emissions from vehicle exhaust, and emissions releases from industrial processes like a...

Compound-specific stable carbon isotopic composition of petroleum hydrocarbons as a tool for tracing the source of oil spills

International Nuclear Information System (INIS)

Li Yun; Xiong Yongqiang; Yang Wanying; Xie Yueliang; Li Siyuan; Sun Yongge

2009-01-01

With the increasing demand for and consumption of crude oils, oil spill accidents happen frequently during the transportation of crude oils and oil products, and the environmental hazard they pose has become increasingly serious in China. The exact identification of the source of spilled oil can act as forensic evidence in the investigation and handling of oil spill accidents. In this study, a weathering simulation experiment demonstrates that the mass loss of crude oils caused by short-term weathering mainly occurs within the first 24 h after a spill, and is dominated by the depletion of low-molecular weight hydrocarbons ( 18 n-alkanes). Short-term weathering has no significant effect on δ 13 C values of individual n-alkanes (C 12 -C 33 ), suggesting that a stable carbon isotope profile of n-alkanes can be a useful tool for tracing the source of an oil spill, particularly for weathered oils or those with a relatively low concentration or absence of sterane and terpane biomarkers

Bed agglomeration characteristics of palm shell and corncob combustion in fluidized bed

International Nuclear Information System (INIS)

Chaivatamaset, Pawin; Sricharoon, Panchan; Tia, Suvit

2011-01-01

Bed particle agglomeration was studied experimentally in an atmospheric laboratory scale fluidized bed combustor using quartz sand as bed material. Palm shell and corncob were tested. The objectives of the study were (i) to describe the contributions of the biomass ash properties and the operating conditions on the bed agglomeration tendency in term of the bed defluidization time (t def ) and the extent of potassium accumulation in the bed (K/Bed) and (ii) to further elucidate the ash inorganic behaviors and the governing bed agglomeration mechanisms. Defluidization caused by the bed agglomeration was experienced in all experiments during combustion of these biomasses, as a consequence of the presence of potassium in biomass. The experimental results indicated that biomass ash characteristics were the significant influence on the bed agglomeration. The increasing bed temperature, bed particle size and static bed height and the decreasing fluidizing air velocity enhanced the bed agglomeration tendency. The SEM/EDS analyses on the agglomerates confirmed that the agglomeration was attributed to the formation of potassium silicate liquid enriched on the surface of quartz sand particles in conjunction with the high surface temperature of the burning biomass char particles. Thermodynamic examination based on the phase diagram analysis confirmed that the molten phase formation was responsible for the agglomeration. In this study, the high molten ash fraction resulting from the high potassium content in biomass promoted the agglomeration and thus defluidization. - Highlights: → Palm shell and corncob of Thailand are tested their bed agglomeration behaviors during fluidized bed combustion. → The increase of bed temperature, bed particle size and static bed height and the decrease of air velocity enhance bed agglomeration. → The formation of ash derived potassium silicate melts enriched on sand surface is the key process. → The collision between char and sand

The characteristics of bed agglomeration during fluidized bed combustion of eucalyptus bark

International Nuclear Information System (INIS)

Chaivatamaset, Pawin; Tia, Suvit

2015-01-01

The bed agglomeration behaviors were investigated experimentally when eucalyptus bark was burning tested in a laboratory scale fluidized bed reactor. The focuses of this work were the influences of operating conditions and bed materials on the bed agglomeration tendency and the elucidation in the behaviors of fuel inorganic elements and the governing mode of the agglomeration. It was found that the defluidization caused by the bed agglomeration was clearly detectable from the decrease in measured bed pressure. The growth of bed particle and accumulation of agglomerates during combustion provided the partial to complete defluidization. The defluidization was promoted by the increase of bed temperature and bed particle size, and the decrease of fluidizing air velocity. The SEM-EDS analyses revealed that the bed agglomeration was mainly attributed to the formation of potassium silicate compounds as liquid phase during the combustion. This was initiated by the chemical reaction between the bed particle and the released ash constituents. In this study, the inorganic migration from fuel particle to bed particle was likely dominated by the condensation/reaction. The thermodynamic examination by ternary phase diagram analysis corroborated that the liquid phase formation of the ash derived materials controlled the agglomeration. The alumina sand prevented the bed agglomeration since it was inactive in the formation of viscous molten substances during combustion at the observed temperatures. - Highlights: • The behaviors of bed agglomeration were studied during the fluidized bed combustion of eucalyptus bark. • The increase in bed temperature and sand size, and the decrease of air velocity promoted bed defluidization. • The formation of molten potassium silicate compounds conduced to the bed agglomeration. • Condensation/reaction was the dominant inorganic migration mechanism from fuel particle to bed particle. • The alumina sand prevented effectively the bed

Nonpoint source solute transport normal to aquifer bedding in heterogeneous, Markov chain random fields

Science.gov (United States)

Zhang, Hua; Harter, Thomas; Sivakumar, Bellie

2006-06-01

Facies-based geostatistical models have become important tools for analyzing flow and mass transport processes in heterogeneous aquifers. Yet little is known about the relationship between these latter processes and the parameters of facies-based geostatistical models. In this study, we examine the transport of a nonpoint source solute normal (perpendicular) to the major bedding plane of an alluvial aquifer medium that contains multiple geologic facies, including interconnected, high-conductivity (coarse textured) facies. We also evaluate the dependence of the transport behavior on the parameters of the constitutive facies model. A facies-based Markov chain geostatistical model is used to quantify the spatial variability of the aquifer system's hydrostratigraphy. It is integrated with a groundwater flow model and a random walk particle transport model to estimate the solute traveltime probability density function (pdf) for solute flux from the water table to the bottom boundary (the production horizon) of the aquifer. The cases examined include two-, three-, and four-facies models, with mean length anisotropy ratios for horizontal to vertical facies, ek, from 25:1 to 300:1 and with a wide range of facies volume proportions (e.g., from 5 to 95% coarse-textured facies). Predictions of traveltime pdfs are found to be significantly affected by the number of hydrostratigraphic facies identified in the aquifer. Those predictions of traveltime pdfs also are affected by the proportions of coarse-textured sediments, the mean length of the facies (particularly the ratio of length to thickness of coarse materials), and, to a lesser degree, the juxtapositional preference among the hydrostratigraphic facies. In transport normal to the sedimentary bedding plane, traveltime is not lognormally distributed as is often assumed. Also, macrodispersive behavior (variance of the traveltime) is found not to be a unique function of the conductivity variance. For the parameter range

Sources of polycyclic aromatic hydrocarbons to sediments of the Bohai and Yellow Seas in East Asia

Science.gov (United States)

Lin, Tian; Hu, Limin; Guo, Zhigang; Qin, Yanwen; Yang, Zuosheng; Zhang, Gan; Zheng, Mei

2011-12-01

The coasts of Bohai Sea (BS) and Yellow Sea (YS) in China support almost one-quarter of its population and provide more than one-third of the national GDP. BS and YS are downwind of the Asian continental outflow in spring and winter as influenced by the East Asian monsoon. This makes the two seas important sinks of land-based pollutants associated with the Asian continental outflow. The sixteen U.S. EPA proposed priority polycyclic aromatic hydrocarbons (PAHs) in 130 surface sediment samples collected from BS and YS were measured. Combined with our previous PAH data of 90 PM2.5 samples from the upwind areas, the sources of the PAHs in BS and YS were apportioned using positive matrix factorization (PMF) modeling. Four sources were identified: petroleum residue, vehicular emissions, coal combustion and biomass burning. Petroleum residue was the dominant contributor of PAHs in the coast of the Bohai Bay probably due to Haihe River runoff, oil leakage from ships and offshore oil fields. The contribution of vehicular emissions in BS was higher than that in YS, and the reverse was true for coal combustion and biomass burning. This difference in the source patterns in the sediments of the two seas could be attributed to the different PAH emission features of the upwind area related to demographic and economic conditions, as well as the marine geography. The ratios of selected 4-6 ring PAHs in the sediments compared well with those of the PM2.5 of the upwind areas, implicating that the particle phase PAHs in the atmosphere play an important role in the source to sink process of the pyrogenic PAHs in the region.

Distribution of hydrocarbon-utilizing microorganisms and hydrocarbon biodegradation potentials in Alaskan continental shelf areas

International Nuclear Information System (INIS)

Roubal, G.; Atlas, R.M.

1978-01-01

Hydrocarbon-utilizing microogranisms were enumerated from Alaskan continental shelf areas by using plate counts and a new most-probable-number procedure based on mineralization of 14 C-labeled hydrocarbons. Hydrocarbon utilizers were ubiquitously distributed, with no significant overall concentration differences between sampling regions or between surface water and sediment samples. There were, however, significant seasonal differences in numbers of hydrocarbon utilizers. Distribution of hydrocarbon utilizers within Cook Inlet was positively correlated with occurrence of hydrocarbons in the environment. Hydrocarbon biodegradation potentials were measured by using 14 C-radiolabeled hydrocarbon-spiked crude oil. There was no significant correlation between numbers of hydrocarbon utilizers and hydrocarbon biodegradation potentials. The biodegradation potentials showed large seasonal variations in the Beaufort Sea, probably due to seasonal depletion of available nutrients. Non-nutrient-limited biodegradation potentials followed the order hexadecane > naphthalene >> pristane > benzanthracene. In Cook Inlet, biodegradation potentials for hexadecane and naphthalene were dependent on availability of inorganic nutrients. Biodegradation potentials for pristane and benzanthracene were restricted, probably by resistance to attack by available enzymes in the indigenous population

The Anthropogenic Effects of Hydrocarbon Inputs to Coastal Seas: Are There Potential Biogeochemical Impacts?

Science.gov (United States)

Anderson, M. R.; Rivkin, R. B.

2016-02-01

Petroleum hydrocarbon discharges related to fossil fuel exploitation have the potential to alter microbial processes in the upper ocean. While the ecotoxicological effects of such inputs are commonly evaluated, the potential for eutrophication from the constituent organic and inorganic nutrients has been largely ignored. Hydrocarbons from natural seeps and anthropogenic sources represent a measurable source of organic carbon for surface waters. The most recent (1989-1997) estimate of average world-wide input of hydrocarbons to the sea is 1.250 x 1012 g/yr ≈ 1.0 x 1012g C/year. Produced water from offshore platforms is the largest waste stream from oil and gas exploitation and contributes significant quantities of inorganic nutrients such as N, P and Fe. In coastal areas where such inputs are a significant source of these nutrients, model studies show the potential to shift production toward smaller cells and net heterotrophy. The consequences of these nutrient sources for coastal systems and semi enclosed seas are complex and difficult to predict, because (1) there is a lack of comprehensive data on inputs and in situ concentrations and (2) the is no conceptual or quantitative framework to consider their effects on ocean biogeochemical processes. Here we use examples from the North Sea (produced water discharges 1% total riverine input and NH4 3% of the annual riverine nitrogen load), the South China Sea (total petroleum hydrocarbons = 10-1750 μg/l in offshore waters), and the Gulf of Mexico (seeps = 76-106 x 109 gC/yr, Macondo blowout 545 x 109 gC) to demonstrate how hydrocarbon and produced water inputs can influence basin scale biogeochemical and ecosystem processes and to propose a framework to consider these effects on larger scales.

Numerical modeling of pyrolysis of sawdust in a packed bed

Energy Technology Data Exchange (ETDEWEB)

Meng, Qingmin; Chen, Xiaoping [Southeast Univ., Nanjing (China). School of Energy and Environment

2013-07-01

An unsteady, one-dimensional mathematical model has been developed to describe the pyrolysis of sawdust in a packed bed. The sawdust bed was pyrolyzed using the hot gas and an electric heater outside the bed as the source of energy. The developed model includes mass, momentum and energy conservations of gas and solid within the bed. The gas flow in the bed is modeled using Darcy's law for fluid through a porous medium. The heat transfer model includes heat conduction inside the bed and convection between the bed and the hot gas. The kinetic model consists of primary pyrolysis reaction. A finite volume fully implicit scheme is employed for solving the heat and mass transfer model equations. A Runge-Kutta fourth order method is used for the chemical kinetics model equations. The model predictions of mass loss history and temperature were validated with published experimental results, showing a good agreement. The effects of inlet temperature on the pyrolysis process have been analyzed with model simulation. A sensitivity analysis using the model suggests that the predictions could be improved by considering the second reaction which could generate volatile flowing in the void.

Production of hydrogen via conversion of hydrocarbons using a microwave plasma

Energy Technology Data Exchange (ETDEWEB)

Jasinski, Mariusz; Dors, Miroslaw; Nowakowska, Helena; Mizeraczyk, Jerzy [Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk (Poland); Nichipor, Gerietta V, E-mail: mj@imp.gda.pl [Joint Institute of Power and Nuclear Research, Academy of Sciences of Belarus, Minsk, Sosny 220109 (Belarus)

2011-05-18

In this paper, results of hydrogen production from hydrocarbons in an atmospheric pressure microwave plasma are presented. As sources of hydrogen, both methane CH{sub 4} and tetrafluoroethane C{sub 2}H{sub 2}F{sub 4} were tested. A new waveguide-based nozzleless cylinder-type microwave plasma source was used to convert hydrocarbons into hydrogen. The processed gaseous hydrocarbons were introduced into the plasma by four gas ducts which formed a swirl flow in the plasma reactor. The absorbed microwave power was up to 5 kW. The gas flow rate was up to 212 L min{sup -1}. The hydrogen mass yield rate and the corresponding energetic hydrogen mass yield were up to 866 g[H{sub 2}] h{sup -1} and 577 g [H{sub 2}] kWh{sup -1} of microwave energy absorbed by the plasma, respectively. These parameters are better than our previous results when nitrogen was used as a swirl gas and much better than those typical for other plasma methods of hydrogen production (electron beam, gliding arc, plasmatron).

Application of solid phase micro extraction (SPME) in profiling hydrocarbons in oil spill cases

International Nuclear Information System (INIS)

Zuraidah Abdullah Munir; Norashikin Saim; Nurul Huda Mamat Ghani

2008-01-01

In environmental forensic, it is extremely important to have a fast and reliable method in identifying sources of spilled oil and petroleum products. In this study, solid phase micro extraction (SPME) method coupled to gas chromatography-mass spectrometry was developed for the analysis of hydrocarbons in diesel and petroleum contaminated soil samples. Optimization of SPME parameters such as extraction time, extraction temperature and desorption time, was performed using 100-μm poly dimethylsiloxane (PDMS) fiber. These parameters were studied at three levels by means of a central composite experimental design and the optimum experimental conditions were determined using response surface method. The developed SPME method was applied to determine the profiles of hydrocarbons in several oil contaminated soil sample. The SPME method was also used to study the effects of weathering on the profiles of hydrocarbons in unleaded gasoline, diesel and kerosene contaminated soil samples. After several days, significant losses of the lighter hydrocarbons were observed compared to the heavier ones. From these data, SPME method can be used to differentiate possible candidate sources in oil spill cases. (author)

Distributions, Sources, and Backward Trajectories of Atmospheric Polycyclic Aromatic Hydrocarbons at Lake Small Baiyangdian, Northern China

Directory of Open Access Journals (Sweden)

Ning Qin

2012-01-01

Full Text Available Air samples were collected seasonally at Lake Small Baiyangdian, a shallow lake in northern China, between October 2007 and September 2008. Gas phase, particulate phase and dust fall concentrations of polycyclic aromatic hydrocarbons (PAHs were measured using a gas chromatograph-mass spectrometer (GC-MS. The distribution and partitioning of atmospheric PAHs were studied, and the major sources were identified; the backward trajectories of air masses starting from the center of Lake Small Baiyangdian were calculated for the entire year. The following results were obtained: (1 The total concentration of 16 priority controlled PAHs (PAH16 in the gas phase was 417.2±299.8 ng·m−3, in the particulate phase was 150.9±99.2 ng·m−3, and in dust fall was 6930.2±3206.5 ng·g−1. (2 Vehicle emission, coal combustion, and biomass combustion were the major sources in the Small Baiyangdian atmosphere and accounted for 28.9%, 45.1% and 26.0% of the total PAHs, respectively. (3 Winter was dominated by relatively greater PAHs polluted northwesterly air mass pathways. Summer showed a dominant relatively clean southern pathway, whereas the trajectories in autumn and spring might be associated with high pollution from Shanxi or Henan province.

A Contribution to the Problem of Initiation of a Combustion Source in an Oil-Saturated Bed

Science.gov (United States)

Koznacheev, I. A.; Dobrego, K. V.

2013-11-01

The problem on in-situ self-ignition of an oil-saturated bed under the conditions of forced filtration of an oxygen-containing gas has been solved with analytical and numerical methods with account of the burnout of a deficient gas component. The influence of the burnout of this component and of convective removal of heat from the bed on the time of its self-ignition has been determined. Recommendations for the optimum regime of initiation of the self-ignition of the bed with account of variation of the blast flow rate and the oxygen content have been given.

Condensation in Nanoporous Packed Beds.

Science.gov (United States)

Ally, Javed; Molla, Shahnawaz; Mostowfi, Farshid

2016-05-10

In materials with tiny, nanometer-scale pores, liquid condensation is shifted from the bulk saturation pressure observed at larger scales. This effect is called capillary condensation and can block pores, which has major consequences in hydrocarbon production, as well as in fuel cells, catalysis, and powder adhesion. In this study, high pressure nanofluidic condensation studies are performed using propane and carbon dioxide in a colloidal crystal packed bed. Direct visualization allows the extent of condensation to be observed, as well as inference of the pore geometry from Bragg diffraction. We show experimentally that capillary condensation depends on pore geometry and wettability because these factors determine the shape of the menisci that coalesce when pore filling occurs, contrary to the typical assumption that all pore structures can be modeled as cylindrical and perfectly wetting. We also observe capillary condensation at higher pressures than has been done previously, which is important because many applications involving this phenomenon occur well above atmospheric pressure, and there is little, if any, experimental validation of capillary condensation at such pressures, particularly with direct visualization.

Production of hydrogen from hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Lohmueller, R

1984-03-01

Hydrocarbons are the preferred starting materials for the industrial production of hydrogen. Most hydrogen is produced by steam reforming of light hydrocarbons. Partial oxidation of heavy oil and residue is used for the production of H/sub 2/ and synthesis gas in large plants. In both cases gas purification was improved. Hydrogen-rich gases like coke oven gas, refinery-offgas, and offgases from the chemical and petrochemical industry have high potential for becoming a major source of hydrogen. Processes for recovering H/sub 2/ (and by-products) are condensation and rectification at low temperatures and, most attractive and versatile for the production of very pure H/sub 2/, adsorption (PSA). The environmental impact of H/sub 2/ production lies mainly in the emission of CO/sub 2/ and heat. Other forms of pollution can be considerably reduced by conventional methods. The economy of H/sub 2/ production depends essentially on price and availability of the raw materials.

Distribution of aliphatic and polycyclic aromatic hydrocarbon in South China sea sediments

International Nuclear Information System (INIS)

Md Suhaimi Elias; Ab Khalik Wood; Zaleha Hashim; Wee Boon Siong; Nazaratul Ashifa; Mohd Suhaimi Hamzah; Shamsiah Ab Rahman; Ariffin Talib

2006-01-01

Petroleum hydrocarbon (Hcp) consist of three major components namely alkanes, cyclo-alkanes and aromatics. HCP are pollutant and can cause adverse effect to the marine organisms. The study was done to identify the source of pollution in the South China Sea coastal area. The South China Sea is one of the major oil production area in Malaysia. Sampling was done at 15 stations along the coastal area of South China Sea off Peninsular Malaysia, which involved two zone namely coastal (zone 1) and offshore (zone 2) areas. Samples were analyzed using GC-MS for determination of HCP. The results showed, that concentration of aliphatic and polycyclic aromatic hydrocarbon at coastal area, range from 0.51 - 1.31 mg/g and 0.18 - 0.42 mg/g dry weight, respectively whilst, concentration of aliphatic and polycyclic aromatic hydrocarbon at offshore area, range from 0.44 - 1.09 mg/g and 0.20 - 0.49 mg/g dry weight, respectively. SHCP (Aliphatic + PAH) concentration in the sediment at the study area range from 0.64 - 1.68 mg/g dry weight. In this study, it was found that, pollution source for the South China Sea off Peninsular Malaysia was originated from pyrolytic sources (combustion fossil fuel), while some other area had been polluted by pyrolytic or petrogenic (unburned fossil) sources. (Author)

The Space Station Module Power Management and Distribution automation test bed

Science.gov (United States)

Lollar, Louis F.

1991-01-01

The Space Station Module Power Management And Distribution (SSM/PMAD) automation test bed project was begun at NASA/Marshall Space Flight Center (MSFC) in the mid-1980s to develop an autonomous, user-supportive power management and distribution test bed simulating the Space Station Freedom Hab/Lab modules. As the test bed has matured, many new technologies and projects have been added. The author focuses on three primary areas. The first area is the overall accomplishments of the test bed itself. These include a much-improved user interface, a more efficient expert system scheduler, improved communication among the three expert systems, and initial work on adding intermediate levels of autonomy. The second area is the addition of a more realistic power source to the SSM/PMAD test bed; this project is called the Large Autonomous Spacecraft Electrical Power System (LASEPS). The third area is the completion of a virtual link between the SSM/PMAD test bed at MSFC and the Autonomous Power Expert at Lewis Research Center.

The Safety of Hospital Beds: Ingress, Egress, and In-Bed Mobility.

Science.gov (United States)

Morse, Janice M; Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K; Bloswick, Donald

2015-01-01

To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients' ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients' use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated.

Petroleum hydrocarbons

International Nuclear Information System (INIS)

Farrington, J.W.; Teal, J.M.; Parker, P.L.

1976-01-01

Methods for analysis of petroleum hydrocarbons in marine samples are presented. Types of hydrocarbons present and their origins are discussed. Principles and methods of analysis are outlined. Infrared spectrometry, uv spectrometry, gas chromatography, mass spectroscopy, and carbon 14 measurements are described

Organic geochemical characterization of potential hydrocarbon source rocks in the upper Benue Trough

International Nuclear Information System (INIS)

Obaje, N. G.; Pearson, M. J.; Suh, C. E.; Dada, S. S.

1999-01-01

The Upper Benue Trough of Nigeria is the northeastern most portion of the Benue rift structure that extends from the northern limit of the Niger Delta in the south to the southern limit of the Chad basin int he northeast. this portion of the trough is made up of two arms: the Gongola Arm and the Yola Arm. Stratigraphic sequence in the Gongola Arm comprises the continental Albian Bima Sandstone, the transitional Cenomanian Yolde Formation and the marine Turonian - Santonian Gongila, Pindiga, and Fika Formations. Overlying these are the continental Campane - Maastrichtian Gombe Sandstone and the Tertiary Kerri - Kerri Formation. In the Yola Arm, the Turonian - Santonian sequence is replaced by the equally marine Dukul, Jessu, Sekuliye Formations, Numanha Shale, and the Lamja Sandstone. Organic geochemical studies have been carried on outcrop sample form the Gongila, Pindiga, Dukul Formations, the Fika shale and the shaly units of the Gombe Sandstone, with the aim of assessing their source rock potential. Gas Chromatography (GC), Gas Chromatography - Mass Spectrometry (C - MS), and Rock Eval Pyrolysis were the major organic geochemical tools employed. Biomaker hydrocarbon signatures obtained from the GC - MS and the Rock Eval Pyrolysis results indicate that all he formations studied, except the Dukul formation, are immature and are all lean in organic matter

Biodegradation and chemical characterization of petroleum diesel hydrocarbons in seawater at low temperatures

OpenAIRE

Bausch, Alexandre Renee

2010-01-01

Master's thesis in Environmental engineering Petroleum hydrocarbons are a major source of marine contamination. Biodegradation, which is fundamental for the natural attenuation of these hydrocarbons in nature, involves mineralization or transformation of organic compounds by autochthonous microorganism communities. Various limiting factors characteristic of the petroleum, the external environment, and the microbial community determine the fate of oil (e.g., diesel) in the marine environmen...

RF Negative Ion Source Development at IPP Garching

International Nuclear Information System (INIS)

Kraus, W.; McNeely, P.; Berger, M.; Christ-Koch, S.; Falter, H. D.; Fantz, U.; Franzen, P.; Froeschle, M.; Heinemann, B.; Leyer, S.; Riedl, R.; Speth, E.; Wuenderlich, D.

2007-01-01

IPP Garching is heavily involved in the development of an ion source for Neutral Beam Heating of the ITER Tokamak. RF driven ion sources have been successfully developed and are in operation on the ASDEX-Upgrade Tokamak for positive ion based NBH by the NB Heating group at IPP Garching. Building on this experience a RF driven H- ion source has been under development at IPP Garching as an alternative to the ITER reference design ion source. The number of test beds devoted to source development for ITER has increased from one (BATMAN) by the addition of two test beds (MANITU, RADI). This paper contains descriptions of the three test beds. Results on diagnostic development using laser photodetachment and cavity ringdown spectroscopy are given for BATMAN. The latest results for long pulse development on MANITU are presented including the to date longest pulse (600 s). As well, details of source modifications necessitated for pulses in excess of 100 s are given. The newest test bed RADI is still being commissioned and only technical details of the test bed are included in this paper. The final topic of the paper is an investigation into the effects of biasing the plasma grid

HYDROCARBON POLLUTION IN THE NORTH-WESTERN PART OF THE CASPIAN SEA

Directory of Open Access Journals (Sweden)

E. V. Ostrovskaya

2016-01-01

Full Text Available Aim. The paper is aimed to estimate the current level of hydrocarbon pollution of the marine environment in the North-Western part of the Caspian Sea.Methods. The paper discusses the results of three-year studies conducted in 2012-2014 within the framework of Roshydromet’s Programme of monitoring of transboundary waters of the Caspian Sea. Spatial distribution of concentrations of hydrocarbons (total and polyaromatic in water and bottom sediments of the area was analysed. Concentrations of total hydrocarbons were determined by means of infrared spectrometry and PAHs – of gas chromatography with mass spectrometry.Results. The range of the total hydrocarbons in the area’s water is from slight traces to 240 µg/l, in sediments – from traces to 114 µg/g (dry weight. Total concentrations of PAHs in water varied from traces to 321 ng/l, in sediments – from traces to 699 ng/g (dry weight. For the source identification, data of satellite monitoring of the area were used. The data showed increasing input of hydrocarbons coming into the marine environment with discharges from vessels.Conclusion. The results of these studies are compared to those of previous research and show that the level of hydrocarbons in the area is typical for slightly polluted areas.

Application and Discussion of Dual Fluidized Bed Reactor in Biomass Energy Utilization

Science.gov (United States)

Guan, Haibin; Fan, Xiaoxu; Zhao, Baofeng; Yang, Liguo; Sun, Rongfeng

2018-01-01

As an important clean and renewable energy, biomass has a broad market prospect. The dual fluidized bed is widely used in biomass gasification technology, and has become an important way of biomass high-value utilization. This paper describes the basic principle of dual fluidized bed gasification, from the gas composition, tar content and thermal efficiency of the system point of view, analyzes and summarizes several typical dual fluidized bed biomass gasification technologies, points out the existence of gas mixing, the external heat source, catalyst development problems on gas. Finally, it is clear that the gasification of biomass in dual fluidized bed is of great industrial application and development prospect.

Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

Directory of Open Access Journals (Sweden)

R. E. Dunmore

2015-09-01

Full Text Available Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London, which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20–30 % of the total hydrocarbon mixing ratio but comprise more than 50 % of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that 60 % of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50 % of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for, but very significant, under-reporting of diesel-related hydrocarbons; an underestimation of a factor ~4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

Do sealless pumps belong in hydrocarbon processing services?

Energy Technology Data Exchange (ETDEWEB)

Bennett, Shawn L. [Sundyne Corporation, Arvada, CO (Brazil)

2004-07-01

Sealless pump technology seems unimaginable in the hot, dirty and high-pressure world of hydrocarbon processing. Furthermore the high flow rates typical of the industry seem incompatible with sealless pumps. Seals and their environmental controls used in conventional technologies are not immune from these factors making sealless worth another look. In October 2000 the Sealless Centrifugal Pump Specification API 685 was published. This specification lends sealless pumps credibility and emphasizes the proper application of the technology. In many process units seal leaks can be extremely dangerous and costly. The heavy hydrocarbons can auto-ignite and light hydrocarbons will tend to find a source of ignition. The ever-increasing requirements for clean fuels are driving many of the current refinery upgrades. Best Also available control technology requirements and additional focus on Environmental Health and Safety increase the attractiveness of sealless technology to mitigate the hazards associated with seal leaks. Sealless has a place in hydrocarbon processing to eliminate seals, provide mechanical simplification, and ensure personnel/environmental protection. The proper application involves evaluating canned motor/magnetic drive technology, API 685 Guidelines, and vapor pressure versus pump circuit pressure analysis. There are four (4) specific processes where sealless pumps should be targeted: Alkylation, Sulfur Recovery/Hydrotreating, Naphtha Reforming Production, and Neutralization. (author)

Converting high boiling hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Terrisse, H; DuFour, L

1929-02-12

A process is given for converting high boiling hydrocarbons into low boiling hydrocarbons, characterized in that the high boiling hydrocarbons are heated to 200 to 500/sup 0/C in the presence of ferrous chloride and of such gases as hydrogen, water gas, and the like gases under a pressure of from 5 to 40 kilograms per square centimeter. The desulfurization of the hydrocarbons occurs simultaneously.

Bed rest from the perspective of the high-risk pregnant woman.

Science.gov (United States)

Gupton, A; Heaman, M; Ashcroft, T

1997-01-01

To describe the experience of prolonged bed rest from the perspective of women during high-risk pregnancies. A focused ethnographic study that used interviews, participant diaries, and field notes as data sources. Participants were obtained from an acute-care hospital antepartum unit and an antepartum home care program. Twenty-four women with complications of pregnancy requiring prolonged bed rest (range, 7-50 days). A model of the stress process in pregnant women on bed rest emerged from the data analysis. Stressors were grouped into situational (sick role, lack of control, uncertainty, concerns regarding fetus's well-being, and being tired of waiting), environmental (feeling like a prisoner, being bored, and having a sense of missing out), and family (role reversal and worry about older children) categories. Two main mediators of stress were social support and coping. Families, friends, and professionals were perceived as sources of support. Women used coping strategies, such as keeping a positive attitude, taking it 1 day at a time, doing it for the baby, getting used to it, setting goals, and keeping busy. Manifestations of stress were evidenced by adverse physical symptoms, emotional reactions, and altered social relationships. Prolonged bed rest is a stressful experience for pregnant women at high risk. Understanding the stress process in pregnant women confined to bed rest may assist nurses in developing interventions to reduce stressors and enhance mediators.

Integrated Use of n-Alkanes and PAH to Evaluate the Anthropogenic Hydrocarbon Sources and the Toxicity Assessment of Surface Sediments from the Southwestern Coasts of the Caspian Sea

Directory of Open Access Journals (Sweden)

Golshan Shirneshan

2017-07-01

Full Text Available Polycyclic aromatic hydrocarbon (PAH compounds and normal alkanes form a large group of undegradable environmental contaminats. This study aims to determine the sources and distribution of oil pollution (PAH compounds and normal alkanes in the sediments of the southwestern coastal areas of the Caspian Sea and to compare their levels with the relevant standards. For this purpose, 18 surface sediment samples were collected from depths of 10, 20, and 50 meters along two transects in the vertical direction located in the coastal areas of Sangachin and Hashtpar (Gilan Province. The samples were then examined using mass-spectrometric gas chromatography. The origins of n-alkanes were identified using CPI index (0.76-0.95, U/R (3.30‒6.57, and Pristane/Phytane (0.21‒0.42. The sources of PAHs were determined using the index ratios of LMW/HMW (1.93‒13.37, Phenanthrene/Anthracene (11.44‒ 16.7, Chrysene/Benzo (a anthracene (4.69‒10/33, Fluoranthene/Pyrene (0.53‒0.69, and MP/P (0.05‒0.08. Results confirmed the dominant petrogenic source of the hydrocarbons found in the region. The total concentrations of 30 aliphatic hydrocarbons and PAHs in the sediments ranged from 823.8 to 3899.5 µg/g and from 626.95 to 3842.5362 ng/g, respectively. Comparison of the measured PAH concentrations with US sediment quality guidelines revealed that the levels of naphthalene, fluorine, Acenaphthylene, and Acenaphthene exceeded the ERLs at stations with depths of 50m in Sangachin and Hashtpar while comparisons with Canadian standards indicated that they were higher than PELs at all the stations sampled. A major point of great concern is the high concentration of naphthalene as the most toxic PAH compound, which naturally warrants due attention to adopt appropriate management programs.

Coconut endocarp and mesocarp as both biosorbents of dissolved hydrocarbons in fuel spills and as a power source when exhausted.

Science.gov (United States)

Luis-Zarate, Victor Hugo; Rodriguez-Hernandez, Mayra Cecilia; Alatriste-Mondragon, Felipe; Chazaro-Ruiz, Luis Felipe; Rangel-Mendez, Jose Rene

2018-04-01

Health and environmental problems associated with the presence of toxic aromatic compounds in water from oil spills have motivated research to develop effective and economically viable strategies to remove these pollutants. In this work, coconut shell (endocarp), coconut fiber (mesocarp) and coconut shell with fiber (endocarp and mesocarp) obtained from coconut (Cocos nucifera) waste were evaluated as biosorbents of benzene, toluene and naphthalene from water, considering the effect of the solution pH (6-9) and the presence of dissolved organic matter (DOM) in natural water (14 mg/L). In addition, the heat capacity of saturated biosorbents was determined to evaluate their potential as an alternative power source to conventional fossil fuels. Tests of N 2 physisorption, SEM, elemental and fiber analysis, ATR-FTIR and acid-based titrations were performed in order to understand the materials' characteristics, and to elucidate the biosorbents' hydrocarbon adsorption mechanism. Coconut fiber showed the highest adsorption capacities (222, 96 and 5.85 mg/g for benzene, toluene and naphthalene, respectively), which was attributed to its morphologic characteristics and to its high concentration of phenolic groups, associated with the lignin structure. The pH of the solution did not have a significant influence on the removal of the contaminants, and the presence of DOM improved the adsorption capacities of aromatic hydrocarbons. The adsorption studies showed biphasic isotherms, which highlighted the strong affinity between the molecules adsorbed on the biosorbents and the aromatic compounds remaining in the solution. Finally, combustion heat analysis of coconut waste saturated with soluble hydrocarbons showed that the heat capacity increased from 4407.79 cal/g to 5064.43 ± 11.6 cal/g, which is comparable with that of woody biomass (3400-4000 cal/g): this waste biomass with added value could be a promising biofuel. Copyright © 2018 Elsevier Ltd. All rights

Marine controlled source electromagnetic (mCSEM) detects hydrocarbon reservoirs in the Santos Basin - Brazil

Energy Technology Data Exchange (ETDEWEB)

Buonora, Marco Polo Pereira; Rodrigues, Luiz Felipe [PETROBRAS, Rio de Janeiro, RJ (Brazil); Zerilli, Andrea; Labruzzo, Tiziano [WesternGeco, Houston, TX (United States)

2008-07-01

In recent years marine Controlled Source Electromagnetic (mCSEM) has driven the attention of an increasing number of operators due to its sensitivity to map resistive structures, such as hydrocarbon reservoirs beneath the ocean floor and successful case histories have been reported. The Santos basin mCSEM survey was performed as part of a technical co-operation project between PETROBRAS and Schlumberger to assess the integration of selected deep reading electromagnetic technologies into the full cycle of oil field exploration and development. The survey design was based on an in-depth sensitivity study, built on known reservoirs parameters, such as thickness, lateral extent, overburden and resistivities derived from seismic and well data. In this context, the mCSEM data were acquired to calibrate the technology over the area's known reservoirs, quantify the resistivity anomalies associated with those reservoirs, with the expectation that new prospective locations could be found. We show that the mCSEM response of the known reservoirs yields signatures that can be clearly imaged and accurately quantified and there are evident correlations between the mCSEM anomalies and the reservoirs. (author)

Formation of diamonds out of hydrocarbon gas in the earth's mantle

International Nuclear Information System (INIS)

Krason, J.; Szymanski, A.; Savkevitch, S.S.

1991-01-01

This paper discusses the concept of formation of polycrystalline diamonds being discussed dint he context of a very rapid, dynamic decomposition of the hydrocarbon gas, initially biogenic or thermogenic condensed in gas hydrates, naturally locked and highly compressed in the hosting rocks. Gas hydrates are of solid, ice-like composition, mostly of hydrocarbon. Gas hydrates, composed of polyhedral cages, may have two types of structural forms: the body-centered structure or Structure I (small molecules) and diamond lattice or Structure II (large molecules). The crystal structure of the gas hydrate depends on the geometry of gas molecules. The thermodynamic conditions required for stabilization and preservation of the gas hydrates can be changed. Thus, in this concept, the principal source for at least some diamond deposits can originally be highly condensed hydrocarbons. In this case, if all the above indicated thermodynamic conditions and processes are met, naturally precondensed hydrocarbons can be directly converted into polycrystalline, extremely coherent diamonds

Surface geochemical data evaluation and integration with geophysical observations for hydrocarbon prospecting, Tapti graben, Deccan Syneclise, India

OpenAIRE

Satish Kumar, T.; Dayal, A.M.; Sudarshan, V.

2014-01-01

The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable...

Identification of emission sources of particle-bound polycyclic aromatic hydrocarbons in the vicinity of the industrial zone of the city of Novi Sad

Directory of Open Access Journals (Sweden)

Jovčić Nataša S.

2013-01-01

Full Text Available Data on polycyclic aromatic hydrocarbons (PAHs in ambient air accessed at selected locations in the vicinity of the industrial zone of the city of Novi Sad, Serbia, have been presented and analyzed in order to determine seasonal and spatial variations and to identify emission sources of particle-bound PAHs. Previous studies have demonstrated that the major contributors of PAHs in urban areas are the emissions from vehicle exhaust, and emissions releases from industrial processes like aluminium production, creosote and wood preservation, waste incineration, cement manufacture, petrochemical and related industries, commercial heat/power production etc. The sampling campaigns have been conducted at three sampling sites, during the two 14-day periods. The first site was situated near industrial area, with a refinery, power plant and heavy-traffic road in the vicinity. The second site was located nearby the heavy traffic area, especially busy during the rush hour. The third site was residential district. Summer sampling period lasted from June 26th to July 10th 2008, while sampling of ambient air during the winter was undertaken from January 22nd to February 5th 2009. Eighty-four (84 air samples were collected using a high volume air sampler TCR Tecora H0649010/ECHO. 16 US EPA polycyclic aromatic hydrocarbons were determined in all samples using a gas chromatographer with a mass spectrometer as a detector (Shimatzu MDGC/GCMS-2010. The total average concentrations of PAHs ranged from 1.21 to 1.77 ng/m3 during the summer period and from 6.31 to 7.25 ng/m3 in the winter. Various techniques, including diagnostic ratio (DR and principal component analysis (PCA, have been used to define and evaluate potential emission sources of PAHs. Diagnostic ratio analysis indicated that vehicles, diesel or/and gasoline, industrial and combustion emissions were sources of PAHs in the vicinity of the industrial zone. Additionally, principal component analysis was used

7 CFR 2902.15 - Bedding, bed linens, and towels.

Science.gov (United States)

2010-01-01

... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that... minimum biobased content is 12 percent and shall be based on the amount of qualifying biobased carbon in..., and silk are not qualifying biobased feedstocks for the purpose of determining the biobased content of...

Positron induced scattering cross sections for hydrocarbons relevant to plasma

Science.gov (United States)

Singh, Suvam; Antony, Bobby

2018-05-01

This article explores positron scattering cross sections by simple hydrocarbons such as ethane, ethene, ethyne, propane, and propyne. Chemical erosion processes occurring on the surface due to plasma-wall interactions are an abundant source of hydrocarbon molecules which contaminate the hydrogenic plasma. These hydrocarbons play an important role in the edge plasma region of Tokamak and ITER. In addition to this, they are also one of the major components in the planetary atmospheres and astrophysical mediums. The present work focuses on calculation of different positron impact interactions with simple hydrocarbons in terms of the total cross section (Qtot), elastic cross section (Qel), direct ionization cross section (Qion), positronium formation cross section (Qps), and total ionization cross section (Qtion). Knowing that the positron-plasma study is one of the trending fields, the calculated data have diverse plasma and astrophysical modeling applications. A comprehensive study of Qtot has been provided where the inelastic cross sections have been reported for the first time. Comparisons are made with those available from the literature, and a good agreement is obtained with the measurements.

Cyclic Sediment Trading Between Channel and River Bed Sediments

Science.gov (United States)

Haddadchi, A.

2015-12-01

Much of the previous work on sediment tracing has focused on determining either the initial sources of the sediment (soils derive from a particular rock type) or the erosion processes generating the sediment. However, alluvial stores can be both a source and sink for sediment transported by streams. Here geochemical and fallout radionuclide tracing of river-bed and alluvial sediments are used to determine the role of secondary sources, sediment stores, as potential sources of sediment leaving Emu Creek catchment, southeastern Queensland, Australia. Activity concentrations of 137Cs on the river sediments are consistent with channel erosion being the dominant source at all sites sampled along the river. To characterise the deposition and remobilisation cycles in the catchment, a novel geochemical tracing approach was used. Successive pockets of alluvium were treated as discrete sink terms within geochemical mixing models and their source contributions compared with those of river bed sediments collected adjacent to each alluvial pocket. Three different size fractions were examined; silts and clays (banks indicates a high degree of 'trading' between the fluvial space and the alluvial space. Hence, management works aimed at primarily reducing the supply of sediments to the outlet of Emu Creek should focus on rehabilitation of channel banks in the lower catchment.

Morrowan stratigraphy, depositional systems, and hydrocarbon accumulation, Sorrento field, Cheyenne County, Colorado

Energy Technology Data Exchange (ETDEWEB)

Orchard, D.M.; Kidwell, M.R.

1983-08-01

The Sorrento field, located on the western flank of the present-day Las Animas arch in western Cheyenne County, Colorado, has approximately 29 million bbl of oil and 12 bcf of gas in place in sandstones of the Lower Pennsylvanian Morrow units. The sandstones were deposited in a fluvially dominated deltaic system, and the trap for the hydrocarbon accumulation is formed by pinch-out of this deltaic system onto regional dip. The primary reservoirs are point-bar deposits. At the Sorrento field, the basal Keyes limestone member of the Morrow formation rests unconformably on the Mississippian St. Louis Formation. Above the Keyes limestone, the Morrow shale is 180 to 214 ft (55 to 65 m) thick, and locally contains reservoir sands. Gas/oil and oil/water contacts are not uniform through the field owing to discontinuities between separate point bars. One such discontinuity is formed by an apparent mud plug of an abandoned channel separating two point bars on the southeastern end of the field. In a well 7000 ft (2100 m) from the edge of the meander belt, the regressive sequence is represented by a shoreline siltstone unit 8 ft (2 m) thick with flaser bedding, graded bedding, load structures, and rare wave-ripple cross-bedding overlain by 3 ft (1 m) of flood-plain mudstone and coal with no indication of proximity to a nearby sand system.

Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments from the Bering Sea and western Arctic Ocean.

Science.gov (United States)

Zhao, Mengwei; Wang, Weiguo; Liu, Yanguang; Dong, Linsen; Jiao, Liping; Hu, Limin; Fan, Dejiang

2016-03-15

To analyze the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) and evaluate their potential ecological risks, the concentrations of 16 PAHs were measured in 43 surface sediment samples from the Bering Sea and western Arctic Ocean. Total PAH (tPAH) concentrations ranged from 36.95 to 150.21 ng/g (dry weight). In descending order, the surface sediment tPAH concentrations were as follows: Canada Basin>northern Chukchi Sea>Chukchi Basin>southern Chukchi Sea>Aleutian Basin>Makarov Basin>Bering Sea shelf. The Bering Sea and western Arctic Ocean mainly received PAHs of pyrogenic origin due to pollution caused by the incomplete combustion of fossil fuels. The concentrations of PAHs in the sediments of the study areas did not exceed effects range low (ERL) values. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of a clay-based acidic bedding conditioner for dairy cattle bedding.

Science.gov (United States)

Proietto, R L; Hinckley, L S; Fox, L K; Andrew, S M

2013-02-01

This study investigated the effects of a clay-based acidic bedding conditioner on sawdust bedding pH, dry matter (DM), environmental pathogen counts, and environmental bacterial counts on teat ends of lactating dairy cows. Sixteen lactating Holstein cows were paired based on parity, days in milk, milk yield, and milk somatic cell count, and were negative for the presence of an intramammary pathogen. Within each pair, cows were randomly assigned to 1 of 2 treatments with 3-wk periods in a crossover design. Treatment groups consisted of 9 freestalls per group bedded with either untreated sawdust or sawdust with a clay-based acidic bedding conditioner, added at 3- to 4-d intervals over each 21-d period. Bedding and teat ends were aseptically sampled on d 0, 1, 2, 7, 14, and 21 for determination of environmental bacterial counts. At the same time points, bedding was sampled for DM and pH determination. The bacteria identified in the bedding material were total gram-negative bacteria, Streptococcus spp., and coliform bacteria. The bacteria identified on the teat ends were Streptococcus spp., coliform bacteria, and Klebsiella spp. Teat end score, milk somatic cell count, and intramammary pathogen presence were measured weekly. Bedding and teat cleanliness, environmental high and low temperatures, and dew point data were collected daily. The bedding conditioner reduced the pH, but not the DM, of the sawdust bedding compared with untreated sawdust. Overall environmental bacterial counts in bedding were lower for treated sawdust. Total bacterial counts in bedding and on teat ends increased with time over both periods. Compared with untreated sawdust, the treated bedding had lower counts of total gram-negative bacteria and streptococci, but not coliform counts. Teat end bacterial counts were lower for cows bedded on treated sawdust for streptococci, coliforms, and Klebsiella spp. compared with cows bedded on untreated sawdust. The clay-based acidic bedding conditioner

Attenuation of dissolved aromatic hydrocarbons from residual gasoline : source depletion and bioattenuation controls

Energy Technology Data Exchange (ETDEWEB)

Freitas, J.; Yang, T.; Barker, J. [Waterloo Univ., ON (Canada). Dept. of Earth and Environmental Sciences; Mocanu, M. [CH2M Hill Engineering Ltd., Santa Ana, CA (United States); Molson, J. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. of Civil, Mining and Geological Engineering

2008-07-01

It has become commonplace to add ethanol to normal gasoline because this oxygenate has been touted to reduce greenhouse gas emissions, improve air quality and reduce dependence on non-renewable fossil fuels. It is advantageous from a groundwater quality perspective to substitute ethanol for soluble, toxic and mobile monoaromatics such as benzene, toluene, ethylbenzene and xylenes (BTEX). Ethanol poses minimal direct environmental risk, other than the high biological oxygen demand (BOD) imposed on receiving waters. This paper addressed the misconception that fermentation of ethanol to acetate or methane removes this BOD, thus eliminating ethanol as a competitor with BTEX for electron transfers. A study was conducted in which 50 litres each of normal gasoline and gasoline with 10 per cent ethanol (E10) were placed below the water table in a shallow sand aquifer at Canadian Forces Base (CFB) Borden. Two years of monitoring the downgradient plume revealed that the aromatic hydrocarbon were naturally attenuated. Although the rate of mass depletion in gasoline sources could not be predicted from the core analysis and simple interpretations, the biodegradation rate was well captured. It was concluded that the extent of bioattenuation exceeds that predicted by models considering electron acceptor (oxygen) availability. Ethanol was rapidly biotransformed in the Borden aquifer. It did not seem to impair the biotransformation of benzene when both were derived from E10 gasoline. The study revealed that for homogeneous sand aquifers such as Borden, the heterogeneity of sources will likely be a key cause of heterogeneous pollutant distribution in the downgradient plume. Ongoing research will focus on resolving the issue of insufficient oxygen to account for complete mineralization of ethanol and biotransformed aromatics. 14 refs., 1 tab., 7 figs.

Identifying the source of petroleum pollution in sediment cores of southwest of the Caspian Sea using chemical fingerprinting of aliphatic and alicyclic hydrocarbons.

Science.gov (United States)

Shirneshan, Golshan; Bakhtiari, Alireza Riyahi; Memariani, Mahmoud

2017-02-15

In this study, the concentration and sources of aliphatic and petroleum markers were investigated in 105 samples of Anzali, Rezvanshahr and Astara cores from the southwest of Caspian Sea. Petroleum importation was diagnosed as a main source in most depths of cores by the results of unresolved complex mixture, carbon preference index and hopanes and steranes. From the chemical diagnostic parameters, petroleum inputs in sediment of cores were determined to be different during years and the sources of hydrocarbons in some sections differed than Anzali and Turkmenistan and Azerbaijan oils. Diagenic ratios in most sediments of upper and middle sections in Astara core were determined to be highly similar to those of Azerbaijan oil, while the presence of Turkmenistan and Anzali oils were detected in a few sections of Anzali and Rezvanshahr cores and only five layers of downer section in Anzali core, respectively. Copyright © 2016. Published by Elsevier Ltd.

Hydrocarbons from plants: Analytical methods and observations

Energy Technology Data Exchange (ETDEWEB)

Calvin, Melvin

1980-11-01

We have suggested that certain plants rich in hydrocarbon-like materials might be cultivated for renewable photosynthetic products. Two species were selected for experimental plantations: Euphorbia lathyris, an annual from seed and Euphorbia tirucalli, a perennial from cuttings, The yield from each species is over 10 barrels of oil/acre/year without genetic or agronomic improvement. In addition to plants, there are trees, such as species of Copaifera in Brazil and other tropical areas, which produce a diesel-like oil upon tapping. Each tree produces approximately 40 liters of hydrocarbon per year, and this material can be used directly by a diesel-powered car. Further efforts to develop plants as alternate energy sources are underway, as well as a continuing search for additional plant species throughout the world which have a similar capability.

Production of hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Day, D T; Day, R E

1920-04-27

A process is disclosed of converting hydro-carbon oils having high boiling points to hydro-carbon oils having low boiling points, which process comprises adding the oil to be treated to a mass of hydro-carbon oil bearing shale, passing the shale with the oil through a conveyor retort and subjecting the material while in the retort to a heat treatment involving a temperature of at least 500/sup 0/F.

C2-C10 hydrocarbon emissions from a boreal wetland and forest floor

Directory of Open Access Journals (Sweden)

H. Hellén

2006-01-01

Full Text Available Emissions of various C2-C10 hydrocarbons (VOCs and halogenated hydrocarbons (VHOCs from a boreal wetland and a Scots pine forest floor in south-western Finland were measured by the static chamber technique. Isoprene was the main non-methane hydrocarbon emitted by the wetland, but small emissions of ethene, propane, propene, 1-butene, 2-methylpropene, butane, pentane and hexane were also detected. The isoprene emission from the wetland was observed to follow the commonly-used isoprene emission algorithm. The mean emission potential of isoprene was 224 µg m-2 h-1 for the whole season. This is lower than the emission potentials published earlier; that is probably at least partly due to the cold and cloudy weather during the measurements. No emissions were detected of monoterpenes or halogenated hydrocarbons from the wetland. The highest hydrocarbon emissions from the Scots pine forest floor were measured in spring and autumn. However, only a few measurements were conducted during summer. The main compounds emitted were monoterpenes. Isoprene emissions were negligible. The total monoterpene emission rates varied from zero to 373 µg m-2 h-1. The results indicated that decaying plant litter may be the source for these emissions. Small emissions of chloroform (100-800 ng m-2 h-1, ethene, propane, propene, 2-methylpropene, cis-2-butene, pentane, hexane and heptane were detected. Comparison with Scots pine emissions showed that the forest floor may be an important monoterpene source, especially in spring.

An-integrated seismic approach to de-risk hydrocarbon accumulation for Pliocene deep marine slope channels, offshore West Nile Delta, Egypt

Science.gov (United States)

Othman, Adel A. A.; Bakr, Ali; Maher, Ali

2017-12-01

The Nile Delta basin is a hydrocarbon rich province that has hydrocarbon accumulations generated from biogenic and thermogenic source rocks and trapped in a clastic channel reservoirs ranging in age from Pliocene to Early Cretaceous. Currently, the offshore Nile Delta is the most active exploration and development province in Egypt. The main challenge of the studied area is that we have only one well in a channel system exceeds fifteen km length, where seismic reservoir characterization is used to de-risk development scenarios for the field by discriminating between gas sand, water sand and shale. Extracting the gas-charged geobody from the seismic data is magnificent input for 3D reservoir static modelling. Seismic data, being non-stationary in nature, have varying frequency content in time. Spectral decomposition analysis unravels the seismic signal into its initial constituent frequencies. Frequency decomposition of a seismic signal aims to characterize the time-dependent frequency response of subsurface rocks and reservoirs for imaging and mapping of bed thickness, geologic discontinuities and channel connectivity. Inversion feasibility study using crossplot between P-wave impedance (Ip) and S-wave impedance (Is) which derived from well logs (P-wave velocity, S-wave velocity and density) is applied to investigate which inversion type would be sufficient enough to discriminate between gas sand, water sand and shale. Integration between spectral analysis, inversion results and Ip vs. Is crossplot cutoffs help to generate 3D lithofacies cubes, which used to extract gas sand and water sand geobodies, which is extremely wonderful for constructing facies depositional static model in area with unknown facies distribution and sand connectivity. Therefore de-risking hydrocarbon accumulation and GIIP estimation for the field became more confident for drilling new development wells.

Organic maturation levels, thermal history and hydrocarbon source rock potential of the Namurian rocks of the Clare Basin, Ireland

Energy Technology Data Exchange (ETDEWEB)

Goodhue, Robbie; Clayton, Geoffrey [Trinity Coll., Dept. of Geology, Dublin (Ireland)

1999-11-01

Vitrinite reflectance data from two inland cored boreholes confirm high maturation levels throughout the onshore part of the Irish Clare Basin and suggest erosion of 2 to 4 km of late Carboniferous cover and elevated palaeogeothermal gradients in the Carboniferous section. The observed maturation gradients are fully consistent with the published hypothesis of a late Carboniferous/Permian 'superplume' beneath Pangaea but local vertical reversals in gradients also suggest a complex thermal regime probably involving advective heating. The uppermost Visean--lower Namurian Clare Shale is laterally extensive and up to 300 m thick. Although this unit is post-mature, TOC values of up to 15% suggest that it could have considerable hydrocarbon source rock potential in any less mature offshore parts of the basin. (Author)

CO₂ and O₂ respiration kinetics in hydrocarbon contaminated soils amended with organic carbon sources used to determine catabolic diversity.

Science.gov (United States)

Pietravalle, Stéphane; Aspray, Thomas J

2013-05-01

Multiple substrate induced respiration (MSIR) assays which assess the response of soils to carbon source amendment are effective approaches to determine catabolic diversity of soils. Many assays are based on a single short term (hydrocarbon contaminated soils using continuous CO2 and O2 respiration measurements. Based on cumulative CO2 and O2 measurements at 4, 24 and 120 h, the soils were found to be distinct in terms of their catabolic diversity. Most noteworthy, however, was the response to the addition of maleic acid which provided strong evidence of abiotic CO2 efflux to be the overriding process, raising questions about the interpretation of CO2 only responses from organic acid addition in MSIR assays. Copyright © 2013 Elsevier Ltd. All rights reserved.

Selection of bacteria with hydrocarbon degrading capacity isolated from Colombian Caribbean sediments

International Nuclear Information System (INIS)

Narvaez Florez, Silvia; Gomez, Martha L; Martinez Maria M

2008-01-01

Thirty one bacterial isolations in minimal salts supplemented medium with hydrocarbons (ACPM or crude oil) as sole carbon source were isolated from sediment samples from the Colombian Caribbean. Bacterial strains underwent selection tests in different concentrations of hydrocarbons; 11 tolerant crude oil and ACPM strains in a range of 1-8%v/v were chosen. A mixed bacterial culture was created and assessed its ability to degrade hydrocarbons in a laboratory-scale test, with a concentration of 2% v/v of ACPM over a period of 21 days. Measurements of biomass in Colony Forming Units (CFU)/mL were used to develop the growth curve of the mixed culture. Hydrocarbons remotion was measured by mass chromatography. The mixed culture was able to degrade the 68.6% of aliphatic hydrocarbons in preference of long chain n- alkenes (C12- C31), reaching a maximum growth of 3.13 x 10 9 UFC / mL. Degradation of aromatic hydrocarbons was not evidenced under the observation time. Nine of the eleven strains were identified using the biochemical systems BBL and API 50 CHB/E; they belonged to the genus Klebsiella, Chromobacterium, Flavimonas, Enterobacter,Pseudomonas, and Bacillus. The evaluated strains have enzymatic potential to degrade hydrocarbons and it is necessary to characterize them at molecular level in order to develop and effective consortium for field application

Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

Science.gov (United States)

Gargouri, Boutheina; Mhiri, Najla; Karray, Fatma; Aloui, Fathi; Sayadi, Sami

2015-01-01

Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons. PMID:26339653

Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater

Directory of Open Access Journals (Sweden)

Boutheina Gargouri

2015-01-01

Full Text Available Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons.

Pellet bed reactor for multi-modal space power

International Nuclear Information System (INIS)

Buden, D.; Williams, K.; Mast, P.; Mims, J.

1987-01-01

A review of forthcoming space power needs for both civil and military missions indicates that power requirements will be in the tens of megawatts. The electrical power requirements are envisioned to be twofold: long-duration lower power levels will be needed for station keeping, communications, and/or surveillance; short-duration higher power levels will be required for pulsed power devices. These power characteristics led to the proposal of a multi-modal space power reactor using a pellet bed design. Characteristics desired for such a multimegawatt reactor power source are standby, alert, and pulsed power modes; high-thermal output heat source (approximately 1000 MWt peak power); long lifetime station keeping power (10 to 30 years); high temperature output (1500 K to 1800 K); rapid-burst power transition; high reliability (above 95 percent); and stringent safety standards compliance. The proposed pellet bed reactor is designed to satisfy these characteristics

Chebyshev super spectral viscosity method for a fluidized bed model

International Nuclear Information System (INIS)

Sarra, Scott A.

2003-01-01

A Chebyshev super spectral viscosity method and operator splitting are used to solve a hyperbolic system of conservation laws with a source term modeling a fluidized bed. The fluidized bed displays a slugging behavior which corresponds to shocks in the solution. A modified Gegenbauer postprocessing procedure is used to obtain a solution which is free of oscillations caused by the Gibbs-Wilbraham phenomenon in the spectral viscosity solution. Conservation is maintained by working with unphysical negative particle concentrations

Degradation and utilization of polycyclic aromatic hydrocarbons by indigenous soil bacteria

International Nuclear Information System (INIS)

Stetzenbach, L.D.A.

1986-01-01

The persistence of industrially derived polycyclic aromatic hydrocarbons in the subsurface may be significantly affected by the metabolism of soil bacteria. This study was conducted to determine the ability of indigenous soil bacteria to decrease the concentration of four polycyclic aromatic hydrocarbons (naphthalene, fluorene, anthracene, and pyrene) and to utilize the compounds as a substrate for growth. Soil cores from petroleum contaminated and noncontaminated sites contained 10 5 -10 7 viable microorganisms per gram dryweight of soil. Gram negative rod-shaped bacteria predominated. Decreases in the concentration of the four polycyclic aromatic hydrocarbons were observed during incubation with bacterial isolates in aqueous suspension by the use of high performance liquid chromatography. Corresponding increases in bacterial numbers indicated utilization of the compounds as a carbon source. Soil samples from the contaminated sites contained greater numbers of bacteria utilizing anthracene and pyrene than soil samples from uncontaminated sites. Degradation rates of the four polycyclic aromatic hydrocarbons were related to the compound, its concentration, and the bacterium. Biodegradation of pyrene was positively correlated with the presence of oxygen. Pyrene was biodegraded by an Acinetobacter sp. under aerobic conditions but not under anaerobic or microaerophilic conditions. Studies with radiolabeled 14 C-anthracene demonstrated utilization of the labeled carbon as a source of carbon by viable bacterial cells in aqueous suspension. Incorporation of 14 C into cellular biomass however was not observed during incubation of 14 C-anthracene in soil

Polycyclic aromatic hydrocarbons in urban air : concentration levels and patterns and source analysis in Nairobi, Kenya

Energy Technology Data Exchange (ETDEWEB)

Muthini, M.; Yoshimichi, H.; Yutaka, K.; Shigeki, M. [Yokohama National Univ., Yokohama (Japan). Graduate School of Environment and Information Sciences

2005-07-01

Polycyclic aromatic hydrocarbons (PAHs) present in the environment are often the result of incomplete combustion processes. This paper reported concentration levels and patterns of high molecular weight PAHs in Nairobi, Kenya. Daily air samples for 30 different PAHs were collected at residential, industrial and business sites within the city. Samples were then extracted using deuterated PAH with an automated Soxhlet device. Gas chromatography and mass spectrometry (GC-MS) with a capillary column was used to analyze the extracts using a selected ion monitoring (SIM) mode. Statistical analyses were then performed. PAH concentration levels were reported for average, median, standard deviation, range, and Pearson's correlation coefficients. Data were then analyzed for sources using a principal component analysis (PCA) technique and isomer ratio analysis. Nonparametric testing was then conducted to detect inherent differences in PAH concentration data obtained from the different sites. Results showed that pyrene was the most abundant PAH. Carcinogenic PAHs were higher in high-traffic areas. The correlation coefficient between coronene and benzo(ghi)pyrene was high. The PAH isomer ratio analysis demonstrated that PAHs in Nairobi are the product of traffic emissions and oil combustion. Results also showed that PAH profiles were not well separated. It was concluded that source distinction methods must be improved in order to better evaluate PAH emissions in the city. 9 refs., 2 tabs., 1 fig.

[Compositions and residual properties of petroleum hydrocarbon in contaminated soil of the oilfields].

Science.gov (United States)

Hu, Di; Li, Chuan; Dong, Qian-Qian; Li, Li-Ming; Li, Guang-He

2014-01-01

The aims of this study were to determine the compositions and residual properties of petroleum hydrocarbon in soil, as well as to identify the source and weathering degree of the pollution. A total of 5 producing wells in Gudao and Hekou oil producing region of Shengli oilfields were analyzed. More than 50 individual target compounds including straight-and branched-chain alkanes( n-alkanes, pristine and phytane) and polycyclic aromatic hydrocarbons (PAHs) in soil samples and crude oil were determined by gas chromatography-mass spectrometry (GC-MS). The percentages of chain alkanes and PAHs in total solvent extractable matters(TSEM) of soil samples were both much lower than those in the crude oil samples. The compositions of petroleum hydrocarbon in soil samples differed from those in crude oil, which indicated the n-alkanes with carbon numbers contaminated soils, the relationship between the index and petroleum hydrocarbon compounds was analyzed using principal component analysis (PCA). The results showed that the n-alkanes with carbon numbers > 33 and the PAHs with rings between 3 and 5 were much harder to degrade. PCA of 4 indexes for source identification revealed more than 50% of the soil samples were polluted by crude oil, which needs more attention during remediation.

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

Directory of Open Access Journals (Sweden)

C. Liu

2017-09-01

Full Text Available 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

Determination of the sticking coefficient of low-energy hydrocarbon ions

International Nuclear Information System (INIS)

Tichmann, Klaus Markus

2011-01-01

The maximum lifetime of future fusion facilities like ITER will be limited by the retention of radioactive tritium in the vessel walls. The retention is significantly affected by the sticking coefficient of hydrocarbon molecules that form in the machine. Using a particle-beam experiment, this sticking coefficient was determined for multiple species at energies below 200 eV. The equipment for the production of the particle beam was optimised and a new ion source for hydrocarbon ions was developed. Simulations using molecular dynamics were performed in parallel to improve the understanding of the processes at the surface.

Application of radiocarbon analysis and receptor modeling to the source apportionment of PAHs (polycyclic aromatic hydrocarbons) in the atmosphere

International Nuclear Information System (INIS)

Sheffield, A.E.

1988-01-01

The radiocarbon tracer technique was used to demonstrate that polycyclic aromatic hydrocarbons (PAHs) can be used for quantitative receptor modeling of air pollution. Fine-particle samples were collected during December, 1985, in Albuquerque, NM. Motor vehicles (fossil) and residential wood combustion (RWC, modern) were the major PAH-sources. For each sample, the PAH-fraction was solvent-extracted, isolated by liquid chromatography, and analyzed by GC-FID and GC-MS. The PAH-fractions from sixteen samples were analyzed for 14 C by Accelerator Mass Spectrometry. Radiocarbon data were used to calculate the relative RWC contribution (f RWC ) for samples analyzed for 14 C. Normalized concentrations of a prospective motor vehicle tracer, benzo(ghi)perylene (BGP) had a strong, negative correlation with f RWC . Normalized BGP concentrations were used to apportion sources for samples not analyzed for 14 C. Multiple Linear Regression (MLR) vs. ADCS and BGP was used to estimate source profiles for use in Target Factor Analysis (TFA). Profiles predicted by TFA were used in Chemical Mass Balances (CMBs). For non-volatile, stable PAHs, agreement between observed and predicted concentrations was excellent. The worst fits were observed for the most volatile PAHs and for coronene. The total RWC contributions predicted by CMBs correlated well with the radiocarbon data

Biosurfactant production from marine hydrocarbon-degrading consortia and pure bacterial strains using crude oil as carbon source.

Science.gov (United States)

Antoniou, Eleftheria; Fodelianakis, Stilianos; Korkakaki, Emmanouela; Kalogerakis, Nicolas

2015-01-01

Biosurfactants (BSs) are "green" amphiphilic molecules produced by microorganisms during biodegradation, increasing the bioavailability of organic pollutants. In this work, the BS production yield of marine hydrocarbon degraders isolated from Elefsina bay in Eastern Mediterranean Sea has been investigated. The drop collapse test was used as a preliminary screening test to confirm BS producing strains or mixed consortia. The community structure of the best consortia based on the drop collapse test was determined by 16S-rDNA pyrotag screening. Subsequently, the effect of incubation time, temperature, substrate and supplementation with inorganic nutrients, on BS production, was examined. Two types of BS - lipid mixtures were extracted from the culture broth; the low molecular weight BS Rhamnolipids and Sophorolipids. Crude extracts were purified by silica gel column chromatography and then identified by thin layer chromatography and Fourier transform infrared spectroscopy. Results indicate that BS production yield remains constant and low while it is independent of the total culture biomass, carbon source, and temperature. A constant BS concentration in a culture broth with continuous degradation of crude oil (CO) implies that the BS producing microbes generate no more than the required amount of BSs that enables biodegradation of the CO. Isolated pure strains were found to have higher specific production yields than the complex microbial marine community-consortia. The heavy oil fraction of CO has emerged as a promising substrate for BS production (by marine BS producers) with fewer impurities in the final product. Furthermore, a particular strain isolated from sediments, Paracoccus marcusii, may be an optimal choice for bioremediation purposes as its biomass remains trapped in the hydrocarbon phase, not suffering from potential dilution effects by sea currents.

Historical records of polycyclic aromatic hydrocarbon deposition in a shallow eutrophic lake: Impacts of sources and sedimentological conditions.

Science.gov (United States)

Li, Chaocan; Huo, Shouliang; Yu, Zhiqiang; Guo, Wei; Xi, Beidou; He, Zhuoshi; Zeng, Xiangying; Wu, Fengchang

2016-03-01

Sediment core samples collected from Lake Chaohu were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) to assess the spatial and temporal distributions of the PAHs during lacustrine sedimentary processes and regional economic development. Assessing the PAH sedimentary records over an approximately 100-year time span, we identified two stages in the PAH inputs and sources (before the 1970s and after the 1970s) in the eastern lake region near a village, whereas three stages (before the 1950s, 1950s-1990s and after the 1990s) were identified in the western lake region near urban and industrial areas. Rapid increases in the PAH depositional fluxes occurred during the second stage due to increased human activities in the Lake Chaohu basin. The composition and isomeric ratios of the PAHs revealed that pyrolysis is the main source of PAHs in this lake. Strong positive relationships between PAH concentration and the total organic carbon concentration, sediment grain size (energy consumption and the levels of urban industrialization and civilization, affect both the composition and abundance of the PAHs. Copyright © 2015. Published by Elsevier B.V.

Greater bottoms upgrading with Albemarle's e-bed catalysts

Energy Technology Data Exchange (ETDEWEB)

Toshima, H.; Sedlacek, Z.; Backhouse, D.; Mayo, S.; Plantenga, F. [Albemarle Catalysts, Houston, TX (United States)

2006-07-01

The E-bed process is a heavy oil upgrading technology that produces near isothermal reactor conditions at a constant catalytic activity. However, E-bed conversion optimization is limited by reactor and downstream fouling problems caused by asphaltene precipitation. While asphaltene precipitation can controlled by reducing hydrogenation, high hydrogenation activity is needed for the removal of sulfur and heavy metals. This presentation described an asphaltene molecule management concept to reduce the fouling of E-bed units. Sediment reduction and high hydrogenation catalysts were used in a modified E-bed process with a variety of feeds and operating conditions. It was observed that the KF1312 catalyst achieved much higher sediment-reduction capability along with satisfactory hydrogenation activity with the different kinds of crude oil sources tested. The catalyst hydrocracked the asphaltenes into smaller molecules, which created greater asphaltene solubility. The sediment reduction capacity of the catalyst-staging technology is now being optimized. It was concluded that the technology will help to reduce fouling in E-bed processes and lead to improved conversion rates for refineries. refs., tabs., figs.

Hydrocarbon preservation conditions in Mesozoic–Paleozoic marine strata in the South Yellow Sea Basin

Directory of Open Access Journals (Sweden)

Jie Liang

2017-11-01

Full Text Available In the South Yellow Sea Basin, Mesozoic–Paleozoic marine strata are generally well developed with large thickness, and they are characterized by multi-source and multi-stage hydrocarbon accumulation, providing a material basis for the formation of large-scale oil and gas fields. However, no substantial breakthrough has been made in this area. Based on previous research results, the complex tectonic pattern of this superimposed basin was formed by multi-stage tectonic movements and the favorable static conditions for hydrocarbon preservation were reworked or destroyed by later superimposition. Therefore, hydrocarbon preservation conditions are the key factors for restricting the breakthrough of marine oil and gas exploration in this area. In this paper, hydrocarbon preservation conditions of marine strata in the South Yellow Sea Basin were comprehensively analyzed from many aspects, such as tectonic movement, source conditions, caprock characteristics, magmatic activities, and hydrogeological and hydrogeochemical characteristics. It is indicated that the complex tectonic pattern of the South Yellow Sea Basin is resulted from tectonic events in multiple stages, and the development and evolution of regional source rocks are mainly controlled by two stages (i.e., the stable evolution stage of Mesozoic–Paleozoic marine basin and the Mesozoic–Cenozoic tectonic pattern transformation and basin formation stage, so the characteristics of differential oil and gas preservation are presented. Besides, better marine hydrocarbon preservation preconditions in this area are weaker tectonic reworking, development of high-quality thick source rocks, good vertical sealing capacity of caprocks, weaker magmatic activity and confined hydrogeological conditions. It is concluded that the Laoshan Uplift in the central part of the South Yellow Sea Basin is structurally stable with weaker faulting and magmatic activities, so it is better in oil and gas preservation

Petroleum hydrocarbon concentrations in eight mollusc species along Tamilnadu coast, Bay of Bengal, India.

Science.gov (United States)

Veerasingam, S; Venkatachalapathy, R; Sudhakar, S; Raja, P; Rajeswari, V

2011-01-01

Eight mollusc species and sediment samples collected from three different stations along Tamilnadu coast, Bay of Bengal, India were analysed for the levels of petroleum hydrocarbons to elucidate the status of the petroleum residues in mollusc meant for human consumption. The concentrations of petroleum hydrocarbons in sediments along Tamilnadu coast varied from 5.04-25.5 microg/g dw (dry weight). High concentration of petroleum hydrocarbons in the sediment of Uppanar estuary (25.5 +/- 1.45 microg/g dw) was perhaps land and marine based anthropogenic sources of this region. The petroleum hydrocarbon residues in eight mollusc species collected from Uppanar, Vellar and Coleroon estuaries varied between 2.44-6.04 microg/g ww (wet weight). Although the concentration of petroleum hydrocarbons in sediment of the Uppanar region was markedly higher than the background, the petroleum hydrocarbon residues in mollusc collected from Uppanar estuary did not suggest bioaccumulation. The results signified that industrial growth has affected the aquatic environments and regular monitoring will help to adopt stringent pollution control measures for better management of the aquatic region.

Exploration of hydrocarbon degrading bacteria on soils contaminated by crude oil from South Sumatera

Directory of Open Access Journals (Sweden)

A. Napoleon

2014-07-01

Full Text Available The goal of this research was to explore hydrocarbon degrading bacteria on crude oil contaminated soil with potential to degrade hydrocarbon in oil pollutant. The research started by early August 2013 till January 2014. Soil sampling for this research was taken on several places with contaminated soil location such as Benakat, Rimau, and Pengabuan all of it located in South Sumatera. Conclusion from this research Isolates obtained from three (3 sites of contaminated soil and treated using SBS medium were Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pnumoniae, Streptococcus beta hemolisa, Proteus mirabilis, Staphylococcus epidermis and Acinotobacter calcoaceticus. Isolates that survived on 300 ppm of hydrocarbon concentration were Bacillus cereus, Pseudomonas aeruginosa and Acinetobacter cakciaceticus Selected isolates posses the ability to degrade hydrocarbon by breaking hydrocarbon substance as the energy source to support isolates existence up to 1,67 TPH level. Based on results accomplish by this research, we urge for further research involving the capacity of isolates to degrade wide variety of hydrocarbon substance and more to develop the potential of these bacteria for bioremediation.

Diesel oil combustion in fluidized bed; Combustion de aceite diesel en lecho fluidizado

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Cazares, Mario [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1992-07-01

The effect of the fluidized bed depth in the combustion in burning diesel oil in a fluidized bed, was analyzed. A self sustained combustion was achieved injecting the oil with an injector that utilized a principle similar to an automobile carburetor venturi. Three different depths were studied and it was found that the deeper the bed, the greater the combustion efficiency. Combustion efficiencies were attained from 82% for a 100mm bed depth, up to 96% for a 200mm bed depth. The diminution in the efficiency was mainly attributed to unburned hydrocarbons and to the carbon carried over, which was observed in the black smoke at the stack outlet. Other phenomena registered were the temperature gradient between the lower part of the bed and the upper part, caused by the fluidization velocity; additionally it was observed that the air employed for the oil injection (carbureting air) is the most important parameter to attain a complete combustion. [Espanol] Se analizo el efecto de la profundidad del lecho en la combustion al quemar aceite diesel en un lecho fluidizado experimental. Se logro combustion autosostenida inyectando el aceite con un inyector que utilizo un principio similar al venturi del carburador de automovil. Se estudiaron tres diferentes profundidades del lecho y se encontro que a mayor profundidad del lecho, mayor eficiencia de la combustion. Se lograron eficiencias de la combustion desde 82% para el lecho de 100 mm de profundidad hasta 96% para el de 200 mm. La disminucion de la eficiencia se atribuyo, principalmente, a los hidrocarburos no quemados y al carbon arrastrado, lo cual se observo en el humo negro a la salida de la chimenea. Otros fenomenos registrados fueron el gradiente de temperatura entre la parte baja del lecho y la parte superior causado por la velocidad de fluidizacion; ademas, se observo que el aire utilizado para inyectar el aceite (aire de carburacion) es el parametro mas importante para lograr una combustion completa.

Performance of a Throttle Cycle Refrigerator with Nitrogen-Hydrocarbon and Argon-Hydrocarbon Mixtures

Science.gov (United States)

Venkatarathnam, G.; Senthil Kumar, P.; Srinivasa Murthy, S.

2004-06-01

Throttle cycle refrigerators are a class of vapor compression refrigerators that can provide refrigeration at cryogenic temperatures and operate with refrigerant mixtures. The performance of our prototype refrigerators with nitrogen-hydrocarbon, nitrogen-hydrocarbon-helium and argon-hydrocarbon refrigerant mixtures is presented in this paper.

Purifying hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Demoulins, H D; Garner, F H

1923-02-07

Hydrocarbon distillates, including natural gases and vapors produced by cracking hydrocarbon oils, are desulfurized etc. by treating the vapor with an aqueous alkaline solution of an oxidizing agent. The hydrocarbons may be previously purified by sulfuric acid. In examples aqueous solutions of sodium or calcium hydrochlorite containing 1.5 to 5.0 grams per liter of available chlorine and sufficient alkali to give an excess of 0.1 percent in the spent reagent are preheated to the temperature of the vapor, and either sprayed or atomized into the vapors near the outlet of the dephlegmator or fractionating tower, or passed in countercurrent to the vapors through one or a series of scrubbers.

Direct hydrocarbon exploration and gas reservoir development technology

Energy Technology Data Exchange (ETDEWEB)

Kwak, Young Hoon; Oh, Jae Ho; Jeong, Tae Jin [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); and others

1995-12-01

In order to enhance the capability of petroleum exploration and development techniques, three year project (1994 - 1997) was initiated on the research of direct hydrocarbon exploration and gas reservoir development. This project consists of four sub-projects. (1) Oil(Gas) - source rock correlation technique: The overview of bio-marker parameters which are applicable to hydrocarbon exploration has been illustrated. Experimental analysis of saturated hydrocarbon and bio-markers of the Pohang E and F core samples has been carried out. (2) Study on surface geochemistry and microbiology for hydrocarbon exploration: the test results of the experimental device for extraction of dissolved gases from water show that the device can be utilized for the gas geochemistry of water. (3) Development of gas and gas condensate reservoirs: There are two types of reservoir characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. (4) Numerical modeling of seismic wave propagation and full waveform inversion: Three individual sections are presented. The first one is devoted to the inversion theory in general sense. The second and the third sections deal with the frequency domain pseudo waveform inversion of seismic reflection data and refraction data respectively. (author). 180 refs., 91 figs., 60 tabs.

Hydrocarbons in sediments adjacent to a gas and condensate development and production platform in northwestern Australia

International Nuclear Information System (INIS)

Fischer, S.J.; Alexander, R.; Kagi, R.I.

1994-01-01

In northwestern Australia during the period of 1983 to 1991, 23 wells were drilled from a gas/condensate production platform to the producing formation approximately 3000 m below the sea bed. Low toxicity water-based drilling muds formulated with hydrogenated kerosenes were used, with the resultant formation cuttings being legally discharged into the ocean. To study the fate of hydrocarbons associated with the cuttings, sea-floor samples were collected along two perpendicular transects from the platform. The first extended 10 km in the prevailing direction of the current and the other to 1.2 km. Subsequently, samples have been collected from one of these sites on two occasions, first one year and secondly two years after the initial collection. Samples collected from directly under the platform cuttings chute contained the highest hydrocarbon concentrations, determined gravimetrically, of 75000 mg/kg, decreasing to approximately 40 mg/kg within 800 m in the direction of the prevailing current. Concentrations in the more remote samples were determined by GC and decreased gradually to be barely discernible above background at less than 0.01 mg/kg at 10 km from the platform. This suite of samples provided an excellent opportunity to study the progress of hydrocarbon biodegradation as it occurs in the marine environment. Analysis by GC-FID, GC-MS and GC-FTIR revealed a number of features. For example, the extent of biodegradation and weathering with increasing distance from the platform, and the half life for biodegradation of total hydrocarbons appears to be approximately one year. The hydrocarbon components of the sediments are mainly from the drilling mud with minor contributions from the formation fluids

Hydrocarbon potential of the Trinidad area - 1977

Energy Technology Data Exchange (ETDEWEB)

Persad, K.M.

1978-06-01

It is recognized that deltaic and associated sands, together with porous marine limestones, form the vast majority of the reservoirs in the major accumulations of hydrocarbons throughout the world. The source of the hydrocarbons is now thought to be kerogen which is generated from the organic content of principally marine shales which are formed in or near the continental shelves. The Trinidad area contains several sedimentary subbasins, most of which consist largely of deltaic and associated sediments. These sediments, like most of the ancient deltas of the world, contain major reserves of oil and gas. Other less important reserves should occur in sporadic (time-wise) porous limestones. The total proven and probable reserves of the Trinidad area are around 5 billion bbl of oil, of which 1.6 billion bbl already have been produced, and over 47 TCF of gas.

A study of the microbiology and polycyclic aromatic hydrocarbons ...

African Journals Online (AJOL)

A study was carried out on the drill cuttings from three different oil and gas wells located at Ologbo Community at Edo State with respect to their microbiology and polycyclic aromatic hydrocarbons (PAHs) compositional profile and sources. Isolation and enumeration of heterotrophic bacteria and fungi was carried out using ...

Co-combustion of agricultural wastes in a circulating fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Huseyin Topal; Aysel T. Atimtay [Gazi University, Ankara (Turkey). Dept. of Mechanical Engineering

2005-07-01

In this study a circulating fluidized bed combustion (CFBC) of 125 mm inside diameter and 1800 mm height was used to investigate the co-combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry, and sunflower stems produced as a waste from the edible oil industry with a lignite coal. Lignite coal is a coal most widely used in Turkey. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NOx and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. By changing the operating parameters the variation of emissions of various pollutants were studied. During combustion tests, it was observed that the volatile matter from agro-wastes quickly volatilizes and mostly burn in the riser. The temperature profiles along the bed and the rise also confirmed this phenomenon. It was found that as the volatile matter content of agro-waste increases, the combustion efficiency increases and the combustion takes place more in the upper region of the riser. These results suggest that agro-wastes are potential fuels that can be utilized for clean energy production by using CFBC in countries where agricultural activities are heavy. 3 refs., 4 figs., 5 tabs.

Research on preventive technologies for bed-separation water hazard in China coal mines

Science.gov (United States)

Gui, Herong; Tong, Shijie; Qiu, Weizhong; Lin, Manli

2018-03-01

Bed-separation water is one of the major water hazards in coal mines. Targeted researches on the preventive technologies are of paramount importance to safe mining. This article studied the restrictive effect of geological and mining factors, such as lithological properties of roof strata, coal seam inclination, water source to bed separations, roof management method, dimensions of mining working face, and mining progress, on the formation of bed-separation water hazard. The key techniques to prevent bed-separation water-related accidents include interception, diversion, destructing the buffer layer, grouting and backfilling, etc. The operation and efficiency of each technique are corroborated in field engineering cases. The results of this study will offer reference to countries with similar mining conditions in the researches on bed-separation water burst and hazard control in coal mines.

Electrochemical Routes towards Sustainable Hydrocarbon Fuels

DEFF Research Database (Denmark)

Mogensen, Mogens Bjerg

2012-01-01

The potential of renewable energy and possible solution to the intermittency problem of renewable energy sources like sun and wind are explained. The densest storage of energy is in the form of hydrocarbons. The most suitable method of conversion and storage within a foreseeable future is electro...... in the future. In spite of this, it is important to research and develop as many viable sustainable energy technologies as economical possible. © 2012 ECS - The Electrochemical Society  ...

Upper Pleistocene turbidite sand beds and chaotic silt beds in the channelized, distal, outer-fan lobes of the Mississippi fan

Science.gov (United States)

Nelson, C.H.; Twichell, D.C.; Schwab, W.C.; Lee, H.J.; Kenyon, Neil H.

1992-01-01

Cores from a Mississippi outer-fan depositional lobe demonstrate that sublobes at the distal edge contain a complex local network of channelized-turbidite beds of graded sand and debris-flow beds of chaotic silt. Off-lobe basin plains lack siliciclastic coarse-grained beds. The basin-plain mud facies exhibit low acoustic backscatter on SeaMARC IA sidescan sonar images, whereas high acoustic backscatter characteristic of the lobe sand and silt facies. The depth of the first sand-silt layer correlates with relative backscatter intensity and stratigraphic age of the distal sublobes (i.e., shallowest sand = highest backscatter and youngest sublobe). The high proportion (>50%) of chaotic silt compared to graded sand in the distal, outer-fan sublobes may be related to the unstable, muddy, canyon-wall source areas of the extensive Mississippi delta-fed basin slope. A predominace of chaotic silt in cores or outcrops from outer-fan lobes thus may predict similar settings for ancient fans.

Scheduling admissions and reducing variation in bed demand

NARCIS (Netherlands)

Bekker, R.; Out, P.

2011-01-01

Variability in admissions and lengths of stay inherently leads to variability in bed occupancy. The aim of this paper is to analyse the impact of these sources of variability on the required amount of capacity and to determine admission quota for scheduled admissions to regulate the occupancy

Evaluation of hydrocarbon potential

International Nuclear Information System (INIS)

Cashman, P.H.; Trexler, J.H. Jr.

1992-01-01

Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the open-quotes Eleana Formationclose quotes are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock

Timing of Late Cretaceous Gulf Coast volcanism and chronostratigraphic constraints on deposition of the Ripley Formation from a newly recognized bentonite bed, Pontotoc County, Mississippi

Science.gov (United States)

Vitale, E. J.; Gifford, J.; Platt, B. F.

2017-12-01

forms a synchronous surface in this part of the Cretaceous section. This is significant due to it being a potential previously unknown bout of volcanism, which, if the source can be found, implies a new region that may have experienced thermal maturation of hydrocarbon source rocks at a shallower depth than would have been expected under the normal geothermal gradient.

Distribution of some hydrocarbons in ambient air near Delft and the influence on the formation of secondary air pollutants

NARCIS (Netherlands)

Bos, R.; Guicherit, R.; Hoogeveen, A.

1977-01-01

The relative concentrations of hydrocarbons in the atmosphere may provide information concerning their origin. It appears that the hydrocarbon composition measured in Delft (The Netherlands) is entirely different for northern and southern wind directions. This points to different sources. The most

Polycyclic aromatic hydrocarbons in soils around Guanting Reservoir, Beijing, China

NARCIS (Netherlands)

Jiao, W.T.; Lu, Y.L.; Wang, T.Y.; Li, J.; Han, Jingyi; Wang, G.; Hu, W.Y.

2009-01-01

The concentrations of 16 polycyclic aromatic hydrocarbons ( 16PAHs) were measured by gas chromatography equipped with a mass spectrometry detector (GC-MS) in 56 topsoil samples around Guanting Reservior (GTR), which is an important water source for Beijing. Low to medium levels of PAH contamination

Efficacy of bacterial bioremediation: Demonstration of complete incorporation of hydrocarbons into membrane phospholipids from Rhodococcus hydrocarbon degrading bacteria by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Rodgers, R.P.; Blumer, E.N.; Emmett, M.R.; Marshall, A.G.

2000-02-01

The authors present a method and example to establish complete incorporation of hydrocarbons into membrane phospholipids of putatively bioremediative bacteria. Bacteria are grown on minimal media containing a specified carbon source, either natural abundance or enriched. After extraction (but no other prior separation) of the membrane lipids, electrospray ionization yields a negative-ion FT-ICR mass spectrum containing prominent phospholipid parent ions. If {sup 13}C-enriched hydrocarbon incorporation is complete, then the mass of the parent ion will increase by n Da, in which n is the number of its constituent carbon atoms; moreover, the {sup 13}C isotopic distribution pattern will be reversed. The identities of the constituent fatty acids and polar headgroup are obtained by collisional dissociation (MS/MS), and their extent of {sup 13}C incorporation determined individually. The method is demonstrated for Rhodococcus rhodochrous (ATCC No. 53968), for which all 44 carbons of a representative phosphatidylinositol are shown to derive from the hydrocarbon source. Interestingly, although only C{sub 16} and C{sub 18} alkanes are provided in the growth medium, the bacteria synthesize uniformly enriched C16:0 and C19:0 fatty acids.

Characterization of Bacterial Hydrocarbon Degradation Potential in the Red Sea Through Metagenomic and Cultivation Methods

KAUST Repository

Bianchi, Patrick

2018-02-01

Prokaryotes are the main actors in biogeochemical cycles that are fundamental in global nutrient cycling. The characterization of microbial communities and isolates can enhance the comprehension of such cycles. Potentially novel biochemical processes can be discovered in particular environments with unique characteristics. The Red Sea can be considered as a unique natural laboratory due to its peculiar hydrology and physical features including temperature, salinity and water circulation. Moreover the Red Sea is subjected to hydrocarbon pollution by both anthropogenic and natural sources that select hydrocarbon degrading prokaryotes. Due to its unique features the Red Sea has the potential to host uncharacterized novel microorganisms with hydrocarbondegrading pathways. The focus of this thesis is on the characterization at the metagenomic level of the water column of the Red Sea and on the isolation and characterization of novel hydrocarbon-degrading species and genomes adapted to the unique environmental characteristics of the basin. The presence of metabolic genes responsible of both linear and aromatic hydrocarbon degradation has been evaluated from a metagenomic survey and a meta-analysis of already available datasets. In parallel, water column-based microcosms have been established with crude oil as the sole carbon source, with aim to isolate potential novel bacterial species and provide new genome-based insights on the hydrocarbon degradation potential available in the Red Sea.

Use of biolog methodology for optimizing the degradation of hydrocarbons by bacterial consortia.

Science.gov (United States)

Ambrosoli, R; Bardi, L; Minati, J L; Belviso, S; Ricci, R; Marzona, M

2003-01-01

Biolog methodology was used for the preliminary screening of different cultural conditions in order to detect the best combination/s of factors influencing the metabolic performance of bacterial consortia active in the degradation of hydrocarbons. Two microbial consortia were tested for their activity on 2 hydrocarbons (nonadecane and eicosane) in presence of the following cultural coadjuvants: vegetal oil, beta-cyclodextrine, sodium acetate, mineral solution. Tests were conducted in Biolog MT plates, where only the redox indicator of microbial growth (tetrazolium violet) and no carbon sources are provided. The microwells were filled with various combinations of hydrocarbons, microbial inoculum and coadjuvants. Blanks were prepared with the same combinations but without hydrocarbons. The results obtained show the suitability of the methodology developed to identify the most active consortium and the conditions for its best degradation performance. The efficacy of Biolog methodology (Biolog Inc., USA) for the characterization of microbial communities on the basis of the metabolic profiles obtained on specific carbon sources in the microwells of Elisa-type plates, is widely acknowledged (Garland, 1997; Pietikäinen et al., 2000; Dauber and Wolters, 2000). Due to its aptitude to simultaneously evaluate multiple microbial responses and directly organize the results, it can be adapted to meet specific study purposes (Gamo and Shji, 1999). In the present research Biolog methodology was fitted for the preliminary screening of different cultural conditions, in order to detect the best combination/s of factors influencing the metabolic performance of bacterial consortia active in the degradation of aliphatic hydrocarbons, in view of their utilization for the bioremediation of polluted sites.

Process for the preparation of unsatured hydrocarbons. Verfahren zur Herstellung ungesaettigter Kohlenwasserstoffe

Energy Technology Data Exchange (ETDEWEB)

Tmenov, D N; Svintsov, N I; Schapovalova, L P; Tabakov, A V; Dvoretsky, M L; Vasiliev, G I; Schestovsky, G P; Kandalova, V D; Korotkevitsch, B S; Lukaschov, A I

1980-07-31

Parrafins, olefines or alkyl aromatic compounds can be dehydrated using a catalyst with a molybdenum oxide compound as the active component and magnesium oxide and crystalline clay or titanium oxide or aluminium oxide as carrier. Monoolefines are formed, which are returned to the contact area, and diolefines. The oxygen of the catalyst is used up in the process, so that this has to be regenerated by a gas rich in oxygen at intervals. In order to avoid oxidation cracking by the oxygen, the catalyst must be flushed with an inert gas before reuse. Dehydration occurs in a fluidised bed, where the yield of olefines is increased by dilution of the hydrocarbons by an inert gas.

Screening of hydrocarbons as supercritical ORCs working fluids by thermal stability

International Nuclear Information System (INIS)

Dai, Xiaoye; Shi, Lin; An, Qingsong; Qian, Weizhong

2016-01-01

Highlights: • A rapid evaluation method for thermal stability of hydrocarbons for ORCs. • Methane and hydrogen are confirmed to be decomposition indicators. • The decomposition temperatures for some hydrocarbons using the rapid method. • Long carbon chain hydrocarbons are not suitable for supercritical ORCs. - Abstract: Organic Rankine Cycle (ORC) systems are widely used for industrial waste heat recovery and renewable energy utilization. The supercritical ORC is currently one of the main development directions due to its low exergy loss, high thermal efficiency and high work output. The thermal stability is the major limitation of organic working fluid selection with high temperature heat sources. This paper presents a rapid experimental method for assessing the thermal stability of hydrocarbons for ORCs. The fluids were tested in a high temperature reactor with methane and hydrogen theoretically and experimentally confirmed to be the indicators of thermal decomposition. The thermal decomposition temperatures were obtained for n-hexane, n-pentane, isopentane, cyclopentane, n-butane and isobutane using the rapid experimental method. The results show that cycloalkanes are not the good choices by thermal stability and long carbon chain hydrocarbons (longer than C6) are not suitable for supercritical ORCs due to the thermal stability limitation.

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.

Calibration of an experimental model of tritium storage bed designed for 'in situ' accountability

International Nuclear Information System (INIS)

Bidica, Nicolae; Stefanescu, Ioan; Bucur, Ciprian; Bulubasa, Gheorghe; Deaconu, Mariea

2009-01-01

Full text: Objectives: Tritium accountancy of the storage beds in tritium facilities is an important issue for tritium inventory control. The purpose of our work was to perform calibration of an experimental model of tritium storage bed with a special design, using electric heaters to simulate tritium decay, and to evaluate the detection limit of the accountancy method. The objective of this paper is to present an experimental method used for calibration of the storage bed and the experimental results consisting of calibration curves and detection limit. Our method is based on a 'self-assaying' tritium storage bed. The basic characteristics of the design of our storage bed consists, in principle, of a uniform distribution of the storage material on several copper thin fins (in order to obtain a uniform temperature field inside the bed), an electrical heat source to simulate the tritium decay heat, a system of thermocouples for measuring the temperature field inside the bed, and good thermal isolation of the bed from the external environment. Within this design of the tritium storage bed, the tritium accounting method is based on determining the decay heat of tritium by measuring the temperature increase of the isolated storage bed. Experimental procedure consisted in measuring of temperature field inside the bed for few values of the power injected with the aid of electrical heat source. Data have been collected for few hours and the temperature increase rate was determined for each value of the power injected. Graphical representation of temperature rise versus injected powers was obtained. This accounting method of tritium inventory stored as metal tritide is a reliable solution for in-situ tritium accountability in a tritium handling facility. Several improvements can be done regarding the design of the storage bed in order to improve the measurement accuracy and to obtain a lower detection limit as for instance use of more accurate thermocouples or special

Polycyclic Aromatic Hydrocarbons Bound to PM 2.5 in Urban Coimbatore, India with Emphasis on Source Apportionment

Directory of Open Access Journals (Sweden)

R. Mohanraj

2012-01-01

Full Text Available Coimbatore is one of the fast growing industrial cities of Southern India with an urban population of 1.9 million. This study attempts to evaluate the trends of airborne fine particulates (PM 2.5 and polyaromatic hydrocarbons (PAH on them. The PM 2.5 mass was collected in polytetra fluoroethylene filters using fine particulate sampler at monthly intervals during March 2009 to February 2010. PAHs were extracted from PM 2.5 and estimated by high-performance liquid chromatography. It is alarming to note that PM 2.5 values ranged between 27.85 and 165.75 μg/m3 and exceeded the air quality standards in many sampling events. The sum of 9 PAHs bound to PM 2.5 in a single sampling event ranged from 4.1 to 1632.3 ng/m3. PAH diagnostic ratios and principal component analysis results revealed vehicular emissions and diesel-powered generators as predominant sources of PAH in Coimbatore.

Indications of Hydrocarbons in the Tjörnes Basin, North Iceland

Science.gov (United States)

Richter, B.; Brandsdóttir, B.; Detrick, R.; Helgadóttir, G.; Kjartansson, E.; Gunnarsson, K.; Driscoll, N.; Kent, G.

2002-12-01

The Tjörnes basin, located within the Tjörnes Fracture Zone (TFZ) was initiated during the Miocene (7-9 Ma), following an eastward jump of the spreading axis in N-Iceland. The roughly 150 km long (EW) and 50 km wide (NS) basin has since accumulated a 0.5-4 km thick sedimentary sequence within three extensional grabens, Eyjafjardaráll, Skjálfandadjúp and Öxarfjördur. The transtensional Húsavík-Flatey fault defines the southern margin of the basin. The hangingwalls within the westernmost and deepest graben (Eyjafjardaráll) are transected by series of synthetic and antithetic listric faults. These structures are affiliated with a crustal-scale, listric east- to north-easterly dipping master fault which soles out in the lower crust, at about 7500 m depth. Near shore sediments are exposed on the Tjörnes peninsula, at the eastern margin of the central graben, where a basal unit of Tertiary lava flows, up to 10 Ma old is overlain by 500 m thick Miocene-Pliocene sediments (Tjörnes Beds). Several lignite layers are present within this predominantly marine succession. Multichannel Seismic data show that the Tjörnes Beds extend westwards into the Skjálfandi Bay. In 1989, gas emissions of thermogenic hydrocarbons were detected during a core-drilling in the easternmost basin, Öxarfjördur. Analyses of natural gas-emissions within the geothermal areas at Skógarlón and Skógar in Öxarfjördur also revealed hydrocarbons (methane-hexane) in high concentrations. These gasses probably originate from marine sediments and lignites similar to those found in the Tjörnes Beds. The Tjörnes Beds, as seen in the Tjörnes horst, are thermally immature with respect to petroleum generation. However, based on the tectonic history, this is probably a minimum-maturity indication as organic geochemical analysis and maturation simulations indicate that high geothermal gradient enhances the formation of dry and wet gasses and waxy oil. In 2001 a sidescan sonar imaging was

Developing a source-receptor methodology for the characterization of VOC sources in ambient air

International Nuclear Information System (INIS)

Borbon, A.; Badol, C.; Locoge, N.

2005-01-01

Since 2001, in France, a continuous monitoring of about thirty ozone precursor non-methane hydrocarbons (NMHC) is led in some urban areas. The automated system for NMHC monitoring consists of sub-ambient preconcentration on a cooled multi-sorbent trap followed by thermal desorption and bidimensional Gas Chromatography/Flame Ionisation Detection analysis.The great number of data collected and their exploitation should provide a qualitative and quantitative assessment of hydrocarbon sources. This should help in the definition of relevant strategies of emission regulation as stated by the European Directive relative to ozone in ambient air (2002/3/EC). The purpose of this work is to present the bases and the contributions of an original methodology known as source-receptor in the characterization of NMHC sources. It is a statistical and diagnostic approach, adaptable and transposable in all urban sites, which integrates the spatial and temporal dynamics of the emissions. The methods for source identification combine descriptive or more complex complementary approaches: 1) univariate approach through the analysis of NMHC time series and concentration roses, 2) bivariate approach through a Graphical Ratio Analysis and a characterization of scatterplot distributions of hydrocarbon pairs, 3) multivariate approach with Principal Component Analyses on various time basis. A linear regression model is finally developed to estimate the spatial and temporal source contributions. Apart from vehicle exhaust emissions, sources of interest are: combustion and fossil fuel-related activities, petrol and/or solvent evaporation, the double anthropogenic and biogenic origin of isoprene and other industrial activities depending on local parameters. (author)

Experimental measurement of effective thermal conductivity of packed lithium-titanate pebble bed

International Nuclear Information System (INIS)

Mandal, D.; Sathiyamoorthy, D.; Vinjamur, M.

2012-01-01

Lithium titanate is a promising solid breeder material for the fusion reactor blanket. Packed lithium titanate pebble bed is considered for the blanket. The thermal energy; that will be produced in the bed during breeding and the radiated heat from the reactor core absorbed must be removed. So, the experimental thermal property data are important for the blanket design. In past, a significant amount of works were conducted to determine the effective thermal conductivity of packed solid breeder pebble bed, in helium atmosphere, but no flow of gas was considered. With increase in gas flow rate, effective thermal conductivity of pebble bed increases. Particle size and void fraction also affect the thermal properties of the bed significantly. An experimental facility with external heat source was designed and installed. Experiments were carried out with lithium-titanate pebbles of different sizes at variable gas flow rates and at different bed wall temperature. It was observed that effective thermal conductivity of pebble bed is a function of particle Reynolds number and temperature. From the experimental data two correlations have been developed to estimate the effective thermal conductivity of packed lithium-titanate pebble bed for different particle Reynolds number and at different temperatures. The experimental details and results are discussed in this paper.

Improve The Efficiency Of The Study Of Complex Reservoirs And Hydrocarbon Deposits - East Baghdad Field

Directory of Open Access Journals (Sweden)

Sudad H. Al-Obaidi

2015-08-01

Full Text Available Practical value of this work consists in increasing the efficiency of exploration for oil and gas fields in Eastern Baghdad by optimizing and reducing the complex of well logging coring sampling and well testing of the formation beds and computerizing the data of interpretation to ensure the required accuracy and reliability of the determination of petrophysical parameters that will clarify and increase proven reserves of hydrocarbon fields in Eastern Baghdad. In order to calculate the most accurate water saturation values for each interval of Zubair formation a specific modified form of Archie equation corresponding to this formation was developed.

Growth of fungi on volatile aromatic hydrocarbons: environmental technology perspectives

NARCIS (Netherlands)

Prenafeta Boldú, F.X.

2002-01-01

The present study aimed the better understanding of the catabolism of monoaromatic hydrocarbons by fungi. This knowledge can be used to enhance the biodegradation of BTEX pollutants. Fungi with the capacity of using toluene as the sole source of carbon and energy were isolated by enriching

Hyperspectral reflectance of vegetation affected by underground hydrocarbon gas seepage

NARCIS (Netherlands)

Noomen, M.F.

2007-01-01

Anomalous concentrations of natural gas in the soil may be sourced from leaking underground gas pipelines or from natural microseepages. Due to the explosive nature of hydrocarbon gases, early detection of these gases is essential to avoid dangerous situations. It is known that natural gas in the

14C age of the Satsunai pumice bed, Noboribetsu City, SW Hokkaido, Japan

International Nuclear Information System (INIS)

Kawachi, Shinpei; Matsui, Masaru; Miyasaka, Shogo; Akamatsu, Morio; Kasugai, Akira.

1980-01-01

A sample of carbonized fallen tree piece (Picea or Pinus; diameter 5 cm and length 15 cm) was discovered in a crop in the Noboribetsu pumice flow deposit, where fossil-rootless fumaroles had been found recently. It existed in the loam layer immediately above the Satsunai pumice bed covering the Noboribetsu formation and the fumaroles below it. Its 14 C age was determined to be 11,330 +- 320 Y.B.P. Though the distribution and eruption source of Satsunai pumice bed are still unknown, the 14 C age has significance as follows in the Quaternary chronology. (1) The Satsunai pumice bed is important as a pumice bed indicating the boundary between the pleistocene and the Recent epoch. (2) By means of the Satsunai pumice bed, the age of upper Noboribetsu formation is given. (3) As there is no high bench deposit on the Noboribetsu pumice flow deposit, the time gap may be small between the Satsunai pumice bed and the Noboribetsu formation below it. (J.P.N.)

Characterization of hydrocarbons, halocarbons and carbonyls in the atmosphere of Hong Kong.

Science.gov (United States)

Guo, H; Lee, S C; Louie, P K K; Ho, K F

2004-12-01

Ambient air quality measurements of 156 species including 39 alkanes, 32 alkenes, 2 alkynes, 24 aromatic hydrocarbons, 43 halocarbons and 16 carbonyls, were carried out for 120 air samples collected at two sampling stations (CW and TW) in 2001 throughout Hong Kong. Spatial variations of volatile organic compounds (VOCs) in the atmosphere were investigated. Levels of most alkanes and alkenes at TW site were higher than that at the CW site, while the BTEX concentrations at the two sites were close. The BTEX ratios at CW and TW were 1.6:10.1:1.0:1.6 and 2.1:10.8:1.0:2.0, respectively. For major halogenated hydrocarbons, the mean concentrations of chloromethane, CFCs 12 and 22 did not show spatial variations at the two sites. However, site-specific differences were observed for trichloroethene and tetrachloroethene. Furthermore, there were no significant differences for carbonyls such as formaldehyde, acetaldehyde and acetone between the two sites. The levels of selected hydrocarbons in winter were 1-5 times that in summer. There were no common seasonal trends for carbonyls in Hong Kong. The ambient level of formaldehyde, the most abundant carbonyl, was higher in summer. However, levels of acetaldehyde, acetone and benzaldehyde in winter were 1.6-3.8 times that in summer. The levels of CFCs 11 and 12, and chloromethane in summer were higher than that in winter. Strong correlation of most hydrocarbons with propene and n-butane suggested that the primary contributors of hydrocarbons were vehicular emissions in Hong Kong. In addition, gasoline evaporation, use of solvents, leakage of liquefied petroleum gas (LPG), natural gas leakage and other industrial emissions, and even biogenic emissions affected the ambient levels of hydrocarbons. The sources of halocarbons were mainly materials used in industrial processes and as solvents. Correlation analysis suggested that photochemical reactions made significant contributions to the ambient levels of carbonyls in summer whereas

Modeling of air toxics from hydrocarbon pool fires

International Nuclear Information System (INIS)

Harvey, K.A.; Aydil, M.L.; Barone, J.B.

1996-01-01

While there is guidance for estimating the radiation hazards of fires (ARCHIE), there is little guidance on modeling the dispersion of hazardous materials from fires. The objective of this paper is to provide a review of the methodology used for modeling the impacts of liquid hydrocarbon pool fires. The required input variables for modeling of hydrocarbon pool fires include emission strength, emission duration, and dispersion characteristics. Methods for predicting the products of combustion including the use of literature values, test data, and thermodynamic equilibrium calculations are discussed. The use of energy balances coupled to radiative heat transfer calculations are presented as a method for determining flame temperature. Fire modeling literature is reviewed in order to determine other source release variables such as mass burn rate and duration and flame geometry

Gas-particle distributions, sources and health effects of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in Venice aerosols.

Science.gov (United States)

Gregoris, Elena; Argiriadis, Elena; Vecchiato, Marco; Zambon, Stefano; De Pieri, Silvia; Donateo, Antonio; Contini, Daniele; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

2014-04-01

Air samples were collected in Venice during summer 2009 and 2012 to measure gas and particulate concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). PCB-11, considered a marker for non-Aroclor contamination of the environment, was found for the first time in the Venetian lagoon and in Europe. An investigation on sources has been conducted, evidencing traffic as the major source of PAHs, whereas PCBs have a similar composition to Aroclor 1248 and 1254; in 2009 a release of PCN-42 has been hypothesized. Toxicological evaluation by TCA and TEQ methods, conducted for the first time in Venice air samples, identified BaP, PCB-126 and PCB-169 as the most important contributors to the total carcinogenic activity of PAHs and the total dioxin-like activity of PCBs and PCNs. Copyright © 2014 Elsevier B.V. All rights reserved.

Petrology, palynology and organic geochemistry of Eocene lignite of Matanomadh, Kutch Basin, western India: Implications to depositional environment and hydrocarbon source potential

Energy Technology Data Exchange (ETDEWEB)

Dutta, Suryendu; Mathews, Runcie P.; Saraswati, Pratul K.; Banerjee, Santanu [Department of Earth Sciences, Indian Institute of Technology Bombay (India); Singh, Bhagwan D.; Tripathi, Suryakant M.; Singh, Alpana [Birbal Sahni Institute of Palaeobotany, Lucknow (India); Mann, Ulrich [Forschungszentrum Juelich (Germany). Institut fuer chemie und Dynamik der Geosphaere

2011-01-01

Petrological, palynological and organic-geochemical investigations were undertaken to determine the source vegetation, depositional conditions and hydrocarbon source potential of Eocene Matanomadh lignites from Kutch Basin, western India. The maceral study reveals that studied lignites are rich in huminite (av. 63%) with sub-ordinate amount of liptinite (av. 19%) and low inertinite (av. 3%), along with low to moderately high associated mineral matters (av. 15%). The overall petrographic composition points to a lagoonal condition for the formation of these lignites. The mean huminite reflectance values (R{sub r}: 0.28-0.34%, av. 0.31%) as well as low Rock-Eval T{sub max} (av. 417 C) values for the seams, suggest brown coal or lignitic stage/rank for the studied lignites. The palynological assemblages, dominated by tropical angiospermic pollen, suggest prevalence of warm humid tropical climate during the deposition of these lignites. The total organic carbon (TOC) content of lignites ranges between 26 and 58 wt.%, whereas the TOC content of the associated carbonaceous shales is around 4 wt.%. The Hydrogen Index (HI) ranging from 23 to 452 mg HC/g TOC indicates that the lignite sequence has the potential to produce mixed oil and gaseous hydrocarbons on maturation. The major pyrolysis products of lignites, derived from Curie point pyrolysis-GC-MS, are straight chain aliphatics, phenols and cadalene-based C{sub 15} bicyclic sesquiterpenoids. The exclusive occurrence of C{sub 15} bicyclic sesquiterpenoids suggests that these compounds are derived from dammar resin of angiosperm plants, belonging to family Dipterocarpaceae. (author)

Hydrocarbon Reserves: Abundance or Scarcity

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

Hydrocarbon Reserves: Abundance or Scarcity

International Nuclear Information System (INIS)

2005-01-01

IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

Biosurfactant production from marine hydrocarbon-degrading consortia and pure bacterial strains using crude oil as carbon source

Directory of Open Access Journals (Sweden)

Eleftheria eAntoniou

2015-04-01

Full Text Available Biosurfactants (BS are green amphiphilic molecules produced by microorganisms during biodegradation, increasing the bioavailability of organic pollutants. In this work, the BS production yield of marine hydrocarbon degraders isolated from Elefsina bay in Eastern Mediterranean Sea has been investigated. The drop collapse test was used as a preliminary screening test to confirm biosurfactant producing strains or mixed consortia. The community structure of the best consortia based on the drop collapse test was determined by 16S-rDNA pyrotag screening. Subsequently, the effect of incubation time, temperature, substrate and supplementation with inorganic nutrients, on biosurfactant production, was examined. Two types of BS - lipid mixtures were extracted from the culture broth; the low molecular weight BS Rhamnolipids and Sophorolipids. Crude extracts were purified by silica gel column chromatography and then identified by thin layer chromatography (TLC and Fourier transform infrared spectroscopy (FT-IR. Results indicate that biosurfactant production yield remains constant and low while it is independent of the total culture biomass, carbon source, and temperature. A constant BS concentration in a culture broth with continuous degradation of crude oil implies that the BS producing microbes generate no more than the required amount of biosurfactants that enables biodegradation of the crude oil. Isolated pure strains were found to have higher specific production yields than the complex microbial marine community-consortia. The heavy oil fraction of crude oil has emerged as a promising substrate for BS production (by marine BS producers with fewer impurities in the final product. Furthermore, a particular strain isolated from sediments, Paracoccus marcusii, may be an optimal choice for bioremediation purposes as its biomass remains trapped in the hydrocarbon phase, not suffering from potential dilution effects by sea currents.

Biosurfactant production from marine hydrocarbon-degrading consortia and pure bacterial strains using crude oil as carbon source

Science.gov (United States)

Antoniou, Eleftheria; Fodelianakis, Stilianos; Korkakaki, Emmanouela; Kalogerakis, Nicolas

2015-01-01

Biosurfactants (BSs) are “green” amphiphilic molecules produced by microorganisms during biodegradation, increasing the bioavailability of organic pollutants. In this work, the BS production yield of marine hydrocarbon degraders isolated from Elefsina bay in Eastern Mediterranean Sea has been investigated. The drop collapse test was used as a preliminary screening test to confirm BS producing strains or mixed consortia. The community structure of the best consortia based on the drop collapse test was determined by 16S-rDNA pyrotag screening. Subsequently, the effect of incubation time, temperature, substrate and supplementation with inorganic nutrients, on BS production, was examined. Two types of BS – lipid mixtures were extracted from the culture broth; the low molecular weight BS Rhamnolipids and Sophorolipids. Crude extracts were purified by silica gel column chromatography and then identified by thin layer chromatography and Fourier transform infrared spectroscopy. Results indicate that BS production yield remains constant and low while it is independent of the total culture biomass, carbon source, and temperature. A constant BS concentration in a culture broth with continuous degradation of crude oil (CO) implies that the BS producing microbes generate no more than the required amount of BSs that enables biodegradation of the CO. Isolated pure strains were found to have higher specific production yields than the complex microbial marine community-consortia. The heavy oil fraction of CO has emerged as a promising substrate for BS production (by marine BS producers) with fewer impurities in the final product. Furthermore, a particular strain isolated from sediments, Paracoccus marcusii, may be an optimal choice for bioremediation purposes as its biomass remains trapped in the hydrocarbon phase, not suffering from potential dilution effects by sea currents. PMID:25904907

Near omni-conductors and insulators: Alternant hydrocarbons in the SSP model of ballistic conduction

OpenAIRE

Fowler, P.W.; Sciriha, I.; Borg, M.; Seville, V.E.; Pickup, B.T.

2017-01-01

Within the source-and-sink-potential model, a complete characterisation is obtained for the conduction behaviour of alternant π-conjugated hydrocarbons (conjugated hydrocarbons without odd cycles). In this model, an omni-conductor has a molecular graph that conducts at the Fermi level irrespective of the choice of connection vertices. Likewise, an omni-insulator is a molecular graph that fails to conduct for any choice of connections. We give a comprehensive classification of possible combina...

Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt

International Nuclear Information System (INIS)

Al-Alfy, I.M.; Nabih, M.A.; Eysa, E.A.

2013-01-01

Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. - Highlights: ► The positive DRAD values indicate the hydrocarbon zones in petroleum reservoirs. ► Thorium normalization was applied to determine the hydrocarbon potentialities. ► The conventional well logs are analyzed to determine the net pay zones in wells. ► Determining hydrocarbon potentialities zones using spectrometric gamma-ray logs

Bed mixing dryer for high moisture content fuels

Energy Technology Data Exchange (ETDEWEB)

Hulkkonen, S; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

1998-12-31

Bed mixing dryer is a new type of fuel drying technology for fluidized bed combustion. The idea is to extract hot bed material from the fluidized bed and use it as a heat source for drying the fuel. Drying occurs at steam atmosphere which makes it possible to recover the latent heat of evaporation to process. This improves the thermal efficiency of the power plant process considerably, especially in combined heat and power applications. Imatran Voima Oy (IVO) has developed the Bed Mixing Dryer technology since early 1990s. The first pilot plant was built in 1994 to IVO`s Kuusamo peat and wood fired power plant. The capacity of the plant is 6 MW{sub e} and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since it`s commissioning the dryer has been used successfully for about 3000 hours during the heating season in wintertime. The second application of the technology will be a demonstration project in Oerebro (S). IVO Power Engineering Ltd will supply in 1997 a dryer to Oerebro Energi`s peat, wood and coal fired CHP plant equipped with circulating fluidized bed boiler. The fuel to be dried is sawdust with fuel input of about 60 MW. In Kuusamo the dryer produces 3 MW of additional district heat and in Oerebro 6 MW. The fuels in Kuusamo are peat, saw dust and bark. In addition to the municipal heat production this type of drying technology has its benefits in pulp and paper industry processes. Disposal of paper mill sludges is becoming more difficult and costly which has resulted in need of alternative treatment. Drying of the sludge before combustion in a boiler for power production is an attractive option. At the moment IVO is carrying out several studies to apply the Bed Mixing Dryer in pulp and paper industry processes. Economy of drying the sludge looks promising

Bed mixing dryer for high moisture content fuels

Energy Technology Data Exchange (ETDEWEB)

Hulkkonen, S.; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

1997-12-31

Bed mixing dryer is a new type of fuel drying technology for fluidized bed combustion. The idea is to extract hot bed material from the fluidized bed and use it as a heat source for drying the fuel. Drying occurs at steam atmosphere which makes it possible to recover the latent heat of evaporation to process. This improves the thermal efficiency of the power plant process considerably, especially in combined heat and power applications. Imatran Voima Oy (IVO) has developed the Bed Mixing Dryer technology since early 1990s. The first pilot plant was built in 1994 to IVO`s Kuusamo peat and wood fired power plant. The capacity of the plant is 6 MW{sub e} and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since it`s commissioning the dryer has been used successfully for about 3000 hours during the heating season in wintertime. The second application of the technology will be a demonstration project in Oerebro (S). IVO Power Engineering Ltd will supply in 1997 a dryer to Oerebro Energi`s peat, wood and coal fired CHP plant equipped with circulating fluidized bed boiler. The fuel to be dried is sawdust with fuel input of about 60 MW. In Kuusamo the dryer produces 3 MW of additional district heat and in Oerebro 6 MW. The fuels in Kuusamo are peat, saw dust and bark. In addition to the municipal heat production this type of drying technology has its benefits in pulp and paper industry processes. Disposal of paper mill sludges is becoming more difficult and costly which has resulted in need of alternative treatment. Drying of the sludge before combustion in a boiler for power production is an attractive option. At the moment IVO is carrying out several studies to apply the Bed Mixing Dryer in pulp and paper industry processes. Economy of drying the sludge looks promising

Lithofacies Architecturing and Hydrocarbon Reservoir Potential of Lumshiwal Formation: Surghar Range, Trans-Indus Ranges, North Pakistan

Directory of Open Access Journals (Sweden)

Iftikhar Alam

2015-12-01

Full Text Available Western environs of the Indo-Pak Plate are comprised of thick Mesozoic sedimentary sequence and extensively extended toward Trans-Indus Salt ranges of North Pakistan. This sequence consists of detrital clastic sediments in the lower level and shallow to deep marine sediments in the upper level. In the Trans-Indus Salt ranges the Lumshiwal Formation represents the transitional level of the lower Cretaceous sequence. In Surghar Range the lower part of formation is composed of cyclic alteration of clayey, silty, very fine grained greenish gray, glauconitic sandstone to rusty brownish gray sandstone. The middle part of formation is comprised of thick bedded to massive, cliff forming, sugary texture, whitish to light yellowish gray occasionally rusty brownish gray medium to coarse grained, moderate to well cemented sandstone. The upper part is comprised of feldspathic, ferruginous, weathering yellowish brown, rusty brown to light gray with locally calcareous sandstone beds. The sandstone is reddish to brownish gray, coarse to granules texture, moderately cemented thick bedded to massive. Total thickness of the formation is 220m at Baroch Nala section 230m in Karandi section at a dip of 60°. Along trend lithological variations and diversified primary sedimentary structures which classifies fifteen different sub-lithofacie in Lumshiwal. Middle and upper parts of the formation show massive to thick, current bedded deposits. Lithofacies analysis revealed that the Lumshiwal Formation was deposited in shallow marine for the lower cyclic part to transitionally prodeltaic to deltaic for the middle to upper part respectively. High silica contents in the upper part compare to the middle and lower part of the formation. On the basis of high silica and low alumina with other low fractions of rock fragments, the sandstone is categorized into quartzarenite, sub-litharenite and sub-arkose. Cross beds in the middle and upper parts of formation indicate west to east

Polycyclic aromatic hydrocarbons (PAHs in the atmospheres of two French alpine valleys: sources and temporal patterns

Directory of Open Access Journals (Sweden)

N. Marchand

2004-01-01

Full Text Available Alpine valleys represent some of the most important crossroads for international heavy-duty traffic in Europe, but the full impact of this traffic on air quality is not known due to a lack of data concerning these complex systems. As part of the program "Pollution des Vallées Alpines" (POVA, we performed two sampling surveys of polycyclic aromatic hydrocarbons (PAHs in two sensitive valleys: the Chamonix and Maurienne Valleys, between France and Italy. Sampling campaigns were performed during the summer of 2000 and the winter of 2001, with both periods taking place during the closure of the "Tunnel du Mont-Blanc". The first objective of this paper is to describe the relations between PAH concentrations, external parameters (sampling site localization, meteorological parameters, sources, and aerosol characteristics, including its carbonaceous fraction (OC and EC. The second objective is to study the capacity of PAH profiles to accurately distinguish the different emission sources. Temporal evolution of the relative concentration of an individual PAH (CHR and the PAH groups BghiP+COR and BbF+BkF is studied in order to differentiate wood combustion, gasoline, and diesel emissions, respectively. The results show that the total particulate PAH concentrations were higher in the Chamonix valley during both seasons, despite the cessation of international traffic. Seasonal cycles, with higher concentrations in winter, are also stronger in this valley. During winter, particulate PAH concentration can reach very high levels (up to 155 ng.m-3 in this valley during cold anticyclonic periods. The examination of sources shows the impact during summer of heavy-duty traffic in the Maurienne valley and of gasoline vehicles in the Chamonix valley. During winter, Chamonix is characterized by the strong influence of wood combustion in residential fireplaces, even if the temporal evolution of specific PAH ratios are difficult to interpret. Information on sources

Enhanced aerobic biodegradation of some toxic hydrocarbon pollutants

International Nuclear Information System (INIS)

Elshahawy, M.R.M.

2007-01-01

samples were collected from the same location in Suez Gulf during the period from June, 2004 to April 2006 then microbiologically and chemically analyzed . the TPH levels ranged from 55 to 86 ppm and exceeded the known permissible limits referring to a settled situation of chronic hydrocarbon pollution in the studied area. on the other hand the biodegrading bacterial counts cfu clearly reflected the great adaptation of endogenous bacteria to use hydrocarbons as a sole source of carbon . the ratio of biodegrading bacteria to heterotrophic ones ranged between 26 and 50% over the period of collection. the biodegradation potentials of suez gulf consortia were studied at different concentrations of phenanthrene as a sole carbon source. it was found that the degradation kinetics of phenanthrene either due to biotic or abiotic factors is affected with the initial concentration of PAHs. twenty PAHs degraders were isolated from Suez Gulf consortia after different adaptation periods on phenanthrene.ten isolates were selected to be promising due to their ability to tolerate high base oil concentrations, grow at wide range of temperatures and their short incubation period on MSO. the biodegradation kinetics of 200 ppm phenanthrene by the selected isolates was monitored by HPLC

The combustion of low calorific value fuels (oil shale) by using fluidized bed combustor

International Nuclear Information System (INIS)

Azzam, S.M.

1993-01-01

The present work reports an experimental data for combustion of oil-shale in a fluidized bed combustor. The experimental set up was designed for the combustion of low calorific value fuel such as oil-shale to facilitate the variation of many parameters over a wide operating range. A cold run was firstly conducted to study the fluidization parameters. Fluidization experiment were made with different sized quartiz particles. Minimum fluidization velocities and other fluidization characteristics were determined at room temperature. Secondary a hot run was started, first studying the combustion of 'LPG' in a fluidized bed as a starting process, then studying the combustion if oil-shale with different flow rates. The experimetal results are promising and give rise to hopes that this valuable deposit can be used as a fuel source and can be burned sucessfully in a fluidized bed combustor. This study had prooved that utilization of oil-shale a fuel source is no more a complicated technical problem, this opens the way for power generation using fluidized bed combustors. (author). 17 refs., 32 figs., 3 tabs

The combustion of low calorific value fuels (oil shale) by using fluidized bed combustor

Energy Technology Data Exchange (ETDEWEB)

Azzam, S M

1994-12-31

The present work reports an experimental data for combustion of oil-shale in a fluidized bed combustor. The experimental set up was designed for the combustion of low calorific value fuel such as oil-shale to facilitate the variation of many parameters over a wide operating range. A cold run was firstly conducted to study the fluidization parameters. Fluidization experiment were made with different sized quartiz particles. Minimum fluidization velocities and other fluidization characteristics were determined at room temperature. Secondary a hot run was started, first studying the combustion of `LPG` in a fluidized bed as a starting process, then studying the combustion if oil-shale with different flow rates. The experimetal results are promising and give rise to hopes that this valuable deposit can be used as a fuel source and can be burned sucessfully in a fluidized bed combustor. This study had prooved that utilization of oil-shale a fuel source is no more a complicated technical problem, this opens the way for power generation using fluidized bed combustors. (author). 17 refs., 32 figs., 3 tabs.

A CFD model for biomass combustion in a packed bed furnace

Energy Technology Data Exchange (ETDEWEB)

Karim, Md. Rezwanul [Faculty of Science, Engineering and Technology, Swinburne University of Technology, VIC 3122 (Australia); Department of Mechanical & Chemical Engineering, Islamic University of Technology, Gazipur 1704 (Bangladesh); Ovi, Ifat Rabbil Qudrat [Department of Mechanical & Chemical Engineering, Islamic University of Technology, Gazipur 1704 (Bangladesh); Naser, Jamal, E-mail: jnaser@swin.edu.au [Faculty of Science, Engineering and Technology, Swinburne University of Technology, VIC 3122 (Australia)

2016-07-12

Climate change has now become an important issue which is affecting environment and people around the world. Global warming is the main reason of climate change which is increasing day by day due to the growing demand of energy in developed countries. Use of renewable energy is now an established technique to decrease the adverse effect of global warming. Biomass is a widely accessible renewable energy source which reduces CO{sub 2} emissions for producing thermal energy or electricity. But the combustion of biomass is complex due its large variations and physical structures. Packed bed or fixed bed combustion is the most common method for the energy conversion of biomass. Experimental investigation of packed bed biomass combustion is difficult as the data collection inside the bed is challenging. CFD simulation of these combustion systems can be helpful to investigate different operational conditions and to evaluate the local values inside the investigation area. Available CFD codes can model the gas phase combustion but it can’t model the solid phase of biomass conversion. In this work, a complete three-dimensional CFD model is presented for numerical investigation of packed bed biomass combustion. The model describes the solid phase along with the interface between solid and gas phase. It also includes the bed shrinkage due to the continuous movement of the bed during solid fuel combustion. Several variables are employed to represent different parameters of solid mass. Packed bed is considered as a porous bed and User Defined Functions (UDFs) platform is used to introduce solid phase user defined variables in the CFD. Modified standard discrete transfer radiation method (DTRM) is applied to model the radiation heat transfer. Preliminary results of gas phase velocity and pressure drop over packed bed have been shown. The model can be useful for investigation of movement of the packed bed during solid fuel combustion.

Management bedding : vrijloopstal met composterende bedding van houtsnippers

NARCIS (Netherlands)

Boer, de H.C.; Wiersma, M.; Galama, P.J.; Szanto, G.L.

2015-01-01

In de vrijloopstal liggen de koeien meestal op een organische bedding en scheiden daar mest (feces en urine) uit. Om de bedding voldoende droog en schoon te houden wordt er regelmatig nieuw strooisel aangevoerd en wordt de toplaag bewerkt. Op basis van onderzoek- en praktijkervaringen tot nu toe

Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in Shanghai: the spatio-temporal variation and source identification

Science.gov (United States)

Cheng, Chen; Bi, Chunjuan; Wang, Dongqi; Yu, Zhongjie; Chen, Zhenlou

2018-03-01

This study investigated the dry and wet deposition fluxes of atmospheric polycyclic aromatic hydrocarbons (PAHs) in Shanghai, China. The flux sources were traced based on composition and spatio-temporal variation. The results show that wet deposition concentrations of PAHs ranged from 0.07 to 0.67 mg·L-1 and were correlated with temperature ( P<0.05). Dry deposition of PAHs concentrations ranged from 3.60-92.15 mg·L-1 and were higher in winter and spring than in summer and autumn. The annual PAH average fluxes were 0.631 mg·m-2·d-1 and 4.06 mg·m-2·d-1 for wet and dry deposition, respectively. The highest wet deposition of PAH fluxes was observed in summer, while dry deposition fluxes were higher in winter and spring. Atmospheric PAHs were deposited as dry deposition in spring and winter, yet wet deposition was the dominant pathway during summer. Total atmospheric PAH fluxes were higher in the northern areas than in the southern areas of Shanghai, and were also observed to be higher in winter and spring. Annual deposition of atmospheric PAHs was about 10.8 t in across all of Shanghai. Wet deposition of PAHs was primarily composed of two, three, or four rings, while dry deposition of PAHs was composed of four, five, or six rings. The atmospheric PAHs, composed of four, five, or six rings, primarily existed in the form of particulates. Coal combustion and vehicle emissions were the dominant sources of PAH in the observed area of downtown Shanghai. In suburban areas, industrial pollution, from sources such as coke oven, incinerator, and oil fired power plant, was as significant as vehicle emissions in contributing to the deposition of PAHs.

Effects of strict prolonged bed rest on cardiorespiratory fitness

DEFF Research Database (Denmark)

Ried-Larsen, Mathias; Aarts, Hugo M; Joyner, Michael J

2017-01-01

The aim of this systematic review and meta-analysis [International Prospective Register of Systematic Reviews (PROSPERO) CRD42017055619] was to assess the effects of strict prolonged bed rest (without countermeasures) on maximal oxygen uptake (V̇o2max) and to explore sources of variation therein....

Hydrocarbons and air pollution

International Nuclear Information System (INIS)

Herz, O.

1992-01-01

This paper shows the influence of hydrocarbons vapors, emitted by transports or by volatile solvents using, on air pollution. Hydrocarbons are the principal precursors of photochemical pollution. After a brief introduction on atmospheric chemistry and photochemical reactions, the author describes the french prevention program against hydrocarbons emissions. In the last chapter, informations on international or european community programs for photochemical pollution study are given. 5 figs., 10 tabs

Molecular indicators for palaeoenvironmental change in a Messinian evaporitic sequence (Vena del Gesso, Italy) II. Stratigraphic changes in abundances and (13)C contents of free and sulphur-bound skeletons in a single marl bed

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Kenig, F.; Frewin, N.L.; Hayes, J.M.

1995-01-01

The extractable organic matter of 10 immature samples from a marl bed of one evaporitic cycle of the Vena del Gesso sediments (Gessoso-solfifera Fm., Messinian, Italy) was analyzed quantitatively for free hydrocarbons and organic sulphur compounds. Nickel boride was used as a desulphurizing agent to

Effect of bed particles to combustion of gases in fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Raiko, R.; Wallen, V.; Etelaeaho, R.; Correia, S. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

1997-10-01

The objective of this project was to obtain experimental data on effects of sand particles to the combustion of gases. The effect of the surface area of the particles was tested using different sized particles. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 42 mm surrounded by an electric heater. The test rig was built in the Laboratory of Energy and Process Engineering at Tampere University of Technology. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies were conducted with both fresh bed particles and used bed particles. These measurements indicate that carbon monoxide significantly reacts with oxygen in the particulate or emulsion phase of a fluidized bed, if the residence time is long enough. The reaction rate depends mainly on temperature, air coefficient, residence time and particle size of the solids. It seems that the combustion enhances if the average particle size increases. Whether this is caused by increased free path length or reduced specific surface area of the bed is yet unknown. The first might be more probable cause because the majority of reactions often took place in the freeboard right above the bed. It was clear that the bed hindered proper combustion in several cases. (orig.)

Sources and distribution of polycyclic aromatic hydrocarbons in sediments from the Spanish northern continental shelf. Assessment of spatial and temporal trends

International Nuclear Information System (INIS)

Vinas, Lucia; Angeles Franco, M.; Antonio Soriano, J.; Jose Gonzalez, J.; Pon, Jordi; Albaiges, Joan

2010-01-01

The distribution of polycyclic aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Spanish Northern continental shelf in March and September 2003, and February 2005. Concentrations of PAHs (Σ13 parent components) were in the range of 22-47528 μg/kg dw, the highest values corresponding to coastal urban-industrial hotspots and decreasing offshore. Sediment quality guidelines (SQGs) showed that concentrations of total PAHs were below the threshold effect level (TEC) in 27 stations (81%) and above in 7, two of which (Gijon and Bilbao) were above the probable effect concentration (PEC). The detailed study of diagnostic ratios suggested a rather uniform mixture of petrogenic and pyrolytic PAH sources along the continental shelf, with a slight decrease of the latter moving westwards and offshore. In order to assess the incidence of sediment sampling on the variability of the results, selected stations were also monitored in February and September 2004 and September 2005. The average field variance of the values obtained for each station was 31% that decreased to 23% when the values were normalized to TOC. - PAHs in the Spanish Atlantic coastal sediments reflect chronic inputs of petrogenic and pyrolytic hydrocarbons, with a decrease of the latter moving westwards and offshore and representing low to moderate pollution according to established sediment quality guidelines.

Sources and distribution of polycyclic aromatic hydrocarbons in sediments from the Spanish northern continental shelf. Assessment of spatial and temporal trends

Energy Technology Data Exchange (ETDEWEB)

Vinas, Lucia, E-mail: lucia.vinas@vi.ieo.e [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, Cabo Estai - Canido, 36200 Vigo (Spain); Angeles Franco, M.; Antonio Soriano, J.; Jose Gonzalez, J. [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, Cabo Estai - Canido, 36200 Vigo (Spain); Pon, Jordi [Department of Environmental Chemistry, CID-CSIC, Jordi Girona Salgado, 18-26, 08034-Barcelona (Spain); Albaiges, Joan, E-mail: albqam@cid.csic.e [Department of Environmental Chemistry, CID-CSIC, Jordi Girona Salgado, 18-26, 08034-Barcelona (Spain)

2010-05-15

The distribution of polycyclic aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Spanish Northern continental shelf in March and September 2003, and February 2005. Concentrations of PAHs (SIGMA13 parent components) were in the range of 22-47528 mug/kg dw, the highest values corresponding to coastal urban-industrial hotspots and decreasing offshore. Sediment quality guidelines (SQGs) showed that concentrations of total PAHs were below the threshold effect level (TEC) in 27 stations (81%) and above in 7, two of which (Gijon and Bilbao) were above the probable effect concentration (PEC). The detailed study of diagnostic ratios suggested a rather uniform mixture of petrogenic and pyrolytic PAH sources along the continental shelf, with a slight decrease of the latter moving westwards and offshore. In order to assess the incidence of sediment sampling on the variability of the results, selected stations were also monitored in February and September 2004 and September 2005. The average field variance of the values obtained for each station was 31% that decreased to 23% when the values were normalized to TOC. - PAHs in the Spanish Atlantic coastal sediments reflect chronic inputs of petrogenic and pyrolytic hydrocarbons, with a decrease of the latter moving westwards and offshore and representing low to moderate pollution according to established sediment quality guidelines.

Co-combustion of peach and apricot stone with coal in a bubbling fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Atimtay, Aysel T.; Kaynak, Burcak [Department of Environmental Engineering, Middle East Technical University, Ankara 06531 (Turkey)

2008-02-15

In this study a bubbling fluidized bed combustor (BFBC) having an inside diameter of 102 mm and a height of 900 mm was used to investigate the co-combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry with coal. A lignite coal was used for co-combustion. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub X} and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. Variations of emissions of various pollutants were studied by changing the operating parameters (excess air ratio, fluidization velocity, and fuel feed rate). Temperature distribution along the bed was measured with thermocouples. For co-combustion of apricot and peach fruit stones with a lignite coal, various ratios of biomass to coal ranging from 0 to 100 wt.% were tested. For the peach stone co-combustion tests, efficiencies are about 98% and for the apricot stone co-combustion tests, efficiencies ranged between 94.7% and 96.9% for 25%, 50% and 75% of apricot stone in the fuel mixture. The results of this study have shown that as the biomass ratio in the fuel mixture increases, the combustion takes place at the upper regions of the main column. This causes higher temperatures in the freeboard than the bed. Also the CO and hydrocarbon (C{sub m}H{sub n}) emissions increase as the biomass percentage increases in the fuel mixture. This causes decrease in the combustion efficiency. These results suggest that peach and apricot stones are potential fuels that can be utilized for clean energy production in small-scale fruit juice industries by using BFBC. The percentage of peach stones or apricot stones in the fuel mixture is suggested to be below 50 wt.% in order to obtain the emission limits of EU. During the design of the BFBC, one has to be careful about the volatile matter (VM) content of the biomass. For the complete combustion of the VM, longer freeboard or secondary air addition should be

Bed retained products in swept fixed bed (SFB) coal hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

Mastral, A.M.; Perez-Surio, M.J. [CSIC, Zaragosa (Spain). Inst. de Carboquimica

1997-12-31

The hydropyrolysis of a low rank coal in a swept fixed bed (SFB) reactor is carried out by fixing the hydrogen pressure (40 kg/cm{sup 2}), the hydrogen flow (2 l/min) and the residence time (10 min) at increasing temperatures (400 C, 500 C and 600 C) and coal bed heights (h, 1.5h, 2h, 2.5h and 3h). It is shown that the percentages of tars and char directly depend on the coal bed height and that there is not only a quantitative dependence, but also the height of the coal bed is very important and plays a relevant role on the nature of the conversion products. (orig.)

Seasonal variations and sources of atmospheric polycyclic aromatic hydrocarbons and organochlorine compounds in a high-altitude city: Evidence from four-year observations

Energy Technology Data Exchange (ETDEWEB)

Gong, Ping; Wang, Xiaoping; Sheng, Jiujiang; Wang, Hailong; Yuan, Xiaohua; He, Yuanqing; Qian, Yun; Yao, Tandong

2018-02-01

Lijiang is a high-altitude city located on the eastern fringe of the Tibetan Plateau, with complex seasonal atmospheric circulations (i.e. westerly wind, Indian Monsoon, and East Asia Monsoon). Very few previous studies have focused on seasonal variations and sources of organic pollutants in Lijiang. In this study, a four-year air campaign from June 2009 to July 2013 was conducted to investigate the temporal trends and the sources of polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds [including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs)]. The atmospheric PAH concentrations in winter are 2-3 times of those in summer, probably because of the combined result of enhanced local emission and long-range atmospheric transport (LRAT) during winter. Traffic pollution was the primary local source of PAHs, while biomass burning is the dominant LRAT source. Different from PAHs, OCPs and PCBs mainly underwent LRAT to reach Lijiang. The peak concentrations of most of OCPs occurred in pre-monsoon season and winter, which are carried by air masses from Myanmar and India through westerly winds. As compared with other sites of the Tibetan Plateau, without the direct barrier of the Himalaya, Lijiang is easily contaminated by the incursion of polluted air masses.

Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

International Nuclear Information System (INIS)

Rue-Van Es, J.E. La.

1993-05-01

Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs

Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

Energy Technology Data Exchange (ETDEWEB)

Rue-Van Es, J.E. La.

1993-05-01

Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs.

Distributions of nitrated polycyclic aromatic hydrocarbons in the sediment of Osaka Bay, Japan.

Science.gov (United States)

Uno, Seiichi; Tanaka, Hiroyuki; Kokushi, Emiko; Bacolod, Eugene T; Koyama, Jiro

2017-11-30

The distributions of 15 nitrated polycyclic aromatic hydrocarbons (NPAHs) in sediments collected at 44 sites throughout Osaka Bay, Japan were examined. The highest total NPAHs, with a concentration of 1949ng/kg dry weight, were detected near the city of Amagasaki. Some sites near the cities of Osaka, Kishiwada, sand Sakai registered ng/kg levels of NPAHs, but individual NPAH concentrations were relatively lower than those in previous studies. The sources were estimated using principal component analysis, and NPAHs were derived from exhaust gases of automobiles and industries at some sites. However, our results suggest that it is difficult to estimate the source, especially in coastal areas near big cities and large industrial areas, because the generation pathways between parent polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs are slightly different, and the ratio of PAHs and NPAHs could not be accurately reflect the characters of sources in sediments especially at coastal areas with large-scale industrial zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

In-bed accountability of tritium in production scale metal hydride storage beds

International Nuclear Information System (INIS)

Klein, J.E.

1995-01-01

An ''in-bed accountability'' (IBA) flowing gas calorimetric measurement method has been developed and implemented to eliminate the need to remove tritium from production scale metal hydride storage beds for inventory measurement purposes. Six-point tritium IBA calibration curves have been completed for two, 390 gram tritium metal hydride storage beds. The calibration curves for the two tritium beds are similar to those obtained from the ''cold'' test program. Tritium inventory errors at the 95 percent confidence level ranged from ± 7.3 to 8.6 grams for the cold test results compared to ± 4.2 to 7.5 grams obtained for the two tritium calibrated beds

Distribution, partitioning and sources of polycyclic aromatic hydrocarbons in Daliao River water system in dry season, China

International Nuclear Information System (INIS)

Guo Wei; He Mengchang; Yang Zhifeng; Lin Chunye; Quan Xiangchun; Men Bing

2009-01-01

Eighteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in 29 surface water, 29 suspended particulate matter (SPM), 28 sediment, and 10 pore water samples from Daliao River water system in dry season. The total PAH concentration ranged from 570.2 to 2318.6 ng L -1 in surface water, from 151.0 to 28483.8 ng L -1 in SPM, from 102.9 to 3419.2 ng g -1 in sediment and from 6.3 to 46.4 μg l -1 in pore water. The concentration of dissolved PAHs was higher than that of particulate PAHs at many sites, but the opposite results were generally observed at the sites of wastewater discharge. The soluble level of PAHs was much higher in the pore water than in the water column. Generally, the water column of the polluted branch streams contained higher content of PAHs than their mainstream. The environmental behaviors and fates of PAHs were examined according to some physicochemical parameters such as pH, organic carbon, SPM content, water content and grain size in sediments. Results showed that organic carbon was the primary factor controlling the distribution of the PAHs in the Daliao River water system. Partitioning of PAHs between sediment solid phase and pore water phase was studied, and the relationship between log K oc and log K ow of PAHs on some sediments and the predicted values was compared. PAHs other than naphthalene and acenaphthylene would be accumulated largely in the sediment of the Dalaio River water system. The sources of PAHs were evaluated employing ratios of specific PAHs compounds and different wastewater discharge sources, indicating that combustion was the main source of PAHs input.

Detection of hydrocarbons in irradiated foods

International Nuclear Information System (INIS)

Miyahara, Makoto; Maitani, Tamio; Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko; Kobayashi, Yasuo; Ito, Hitoshi

2003-01-01

The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

Detection of hydrocarbons in irradiated foods

Energy Technology Data Exchange (ETDEWEB)

Miyahara, Makoto; Maitani, Tamio [National Inst. of Health Sciences, Tokyo (Japan); Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Kobayashi, Yasuo; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Establishment

2003-06-01

The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

Concentrations, sources and health effects of parent, oxygenated- and nitrated- polycyclic aromatic hydrocarbons (PAHs) in middle-school air in Xi'an, China

Science.gov (United States)

Wang, Jingzhi; Xu, Hongmei; Guinot, Benjamin; Li, Lijuan; Ho, Steven Sai Hang; Liu, Suixin; Li, Xiaoping; Cao, Junji

2017-08-01

Indoor and outdoor concentrations of polycyclic aromatic hydrocarbons (PAHs), oxygenated-PAHs (OPAHs), and nitro-PAHs (NPAHs) associated with PM2.5 particles were monitored in a middle-school classroom from 8 to 22 March 2012 in Xi'an, China. The total PAHs ranged from 49.6 to 140.0 ng/m3 in outdoors and 50.3 to 111.6 ng/m3 in indoors, while OPAHs and NPAHs showed averages of 19.1 and 16.4 ng/m3, 0.1039 and 0.0785 ng/m3 for outdoor and indoor air, respectively. Strong correlations were found between indoor (I) and outdoor (O), and the I/O ratios were school in Xi'an. Indoor pollutants were mostly influenced by outdoor air. Biomass burning, coal combustion, and vehicle emission were main sources for PAHs. Secondary formation was the main source for OPAHs and NPAHs. Inhalation cancer risks assessment of PAHs showed there were potential health risks for students during sampling time.