WorldWideScience

Sample records for co2 gas sensor

  1. Silicon microring refractometric sensor for atmospheric CO(2) gas monitoring.

    Science.gov (United States)

    Mi, Guangcan; Horvath, Cameron; Aktary, Mirwais; Van, Vien

    2016-01-25

    We report a silicon photonic refractometric CO(2) gas sensor operating at room temperature and capable of detecting CO(2) gas at atmospheric concentrations. The sensor uses a novel functional material layer based on a guanidine polymer derivative, which is shown to exhibit reversible refractive index change upon absorption and release of CO(2) gas molecules, and does not require the presence of humidity to operate. By functionalizing a silicon microring resonator with a thin layer of the polymer, we could detect CO(2) gas concentrations in the 0-500ppm range with a sensitivity of 6 × 10(-9) RIU/ppm and a detection limit of 20ppm. The microring transducer provides a potential integrated solution in the development of low-cost and compact CO(2) sensors that can be deployed as part of a sensor network for accurate environmental monitoring of greenhouse gases.

  2. SnO2/PPy Screen-Printed Multilayer CO2 Gas Sensor

    Directory of Open Access Journals (Sweden)

    S.A. WAGHULEY

    2007-05-01

    Full Text Available Tin dioxide (SnO2 plays a dominant role in solid state gas sensors and exhibit sensitivity towards oxidizing and reducing gases by a variation of its electrical properties. The electrical conducting polymer-polypyrrole (PPy has high anisotropy of electrical conduction and used as a gas sensor. SnO2/PPy multilayer, pure SnO2, pure PPy sensors were prepared by screen-printing method on Al2O3 layer followed by glass substrate. The sensors were used for different concentration (ppm of CO2 gas investigation at room temperature (303 K. The sensitivity of SnO2/PPy multilayer sensor was found to be higher, compared with pure SnO2 and pure PPy sensors. The multilayer sensor exhibited improved stability. The response and recovery time of multilayer sensor were found to be ~2 min and ~10 min respectively.

  3. Wearable CO2 sensor

    OpenAIRE

    Radu, Tanja; Fay, Cormac; Lau, King-Tong; Waite, Rhys; Diamond, Dermot

    2009-01-01

    High concentrations of CO2 may develop particularly in the closed spaces during fires and can endanger the health of emergency personnel by causing serious physiological effects. The proposed prototype provides real-time continuous monitoring of CO2 in a wearable configuration sensing platform. A commercially available electrochemical CO2 sensor was selected due to its selectivity, sensitivity and low power demand. This was integrated onto an electronics platform that performed signal capture...

  4. Optical Transcutaneous pCO2 Sensor using Soft Lithography Method for Arterial Blood Gas Analysis

    Science.gov (United States)

    Kang, Byoung-Ho; Kim, Do-Eok; Leem, Myoung-Kun; Kwon, Dae-Hyuk; Lee, Kwang-Man; Kang, Shin-Won

    2008-10-01

    In this study, we carried out development of non-invasive optical transcutaneous partial pressure of carbon dioxide, pCO2, monitoring system. The purpose of this system is to detect CO2 from outer skin, not from the arterial blood-gathering method. There are advantages about a reduction of analysis time and real-time monitoring that this system might be available. The measurement system is composed of the IR lamp, the pyroelectric sensor including a 4.26 μm optical filter, the optical gas reaction chamber and the signal processing circuit. The optical reaction length of chamber was reduced by 1 mm using the soft-lithography method which CO2 is exhausted in human body as we considered. The fabricated pCO2 monitoring system showed linear result of 6.50×10-6 absorbance/ppm sensitivity for CO2 concentration from 0 ˜5,000 ppm by MFC and about 2 seconds of fast response time. The proposed system can be used in the optical biosensor field for the medical diagnosis such as pCO2 monitoring system and environment monitoring systems.

  5. CdO-based nanostructures as novel CO(2) gas sensors.

    Science.gov (United States)

    Krishnakumar, T; Jayaprakash, R; Prakash, T; Sathyaraj, D; Donato, N; Licoccia, S; Latino, M; Stassi, A; Neri, G

    2011-08-12

    Crystalline Cd(OH)(2)/CdCO(3) nanowires, having lengths in the range from 0.3 up to several microns and 5-30 nm in diameter, were synthesized by a microwave-assisted wet chemical route and used as a precursor to obtain CdO nanostructures after a suitable thermal treatment in air. The morphology and microstructure of the as-synthesized and annealed materials have been investigated by scanning electron microscopy, transmission electron microscopy, x-ray diffraction and thermogravimetry-differential scanning calorimetry. The change in morphology and electrical properties with temperature has revealed a wire-to-rod transformation along with a decreases of electrical resistance. Annealed samples were printed on a ceramic substrate with interdigitated contacts to fabricate resistive solid state sensors. Gas sensing properties were explored by monitoring CO(2) in synthetic air in the concentration range 0.2-5 v/v% (2000-50 000 ppm). The effect of annealing temperature, working temperature and CO(2) concentration on sensing properties (sensitivity, response/recovery time and stability) were investigated. The results obtained demonstrate that CdO-based thick films have good potential as novel CO(2) sensors for practical applications.

  6. Effect of macrostructural control of an auxiliary layer on the CO2 sensing properties of NASICON-based gas sensors

    OpenAIRE

    Morio, Masataka; Hyodo, Takeo; Shimizu, Yasuhiro; Egashira, Makoto

    2009-01-01

    Macrostructural effects of an auxiliary electrode on the CO2 gas sensing properties of NASICON (Na3Zr2Si2PO12) solid-electrolyte sensors were investigated. The sensor with a porous Li2CO3–BaCO3-based auxiliary layer (mp-Sensor), which was prepared by utilizing constituent metal acetates and polymethylmethacrylate microspheres as a template, showed faster CO2 response and recovery and smaller cross-response against humidity changes than those obtained with a dense auxiliary layer without pores...

  7. A long pathlength spectrophotometric pCO(2) sensor using a gas-permeable liquid-core waveguide.

    Science.gov (United States)

    Wang, Zhaohui Aleck; Wang, Yongchen; Cai, Wei-Jun; Liu, Su-Yi

    2002-04-22

    The first long pathlength fiber optic-based sensor system to measure pCO(2) in natural waters and the atmosphere is described. The sensor is based on a liquid-core (an indicator-HCO(3)(-)/CO(3)(2-) buffer solution) waveguide made of a low refractive index amorphous fluoropolymer tubing, the wall of which serves as a gas-permeable membrane to sense pCO(2) changes. The system detects the indicator absorbance changes when the liquid-core reaches CO(2) equilibrium with the surrounding sample. Theoretical calculations demonstrate that due to indicator buffer effects, increasing the optical pathlength is a more efficient way to obtain higher sensitivity than increasing the indicator concentration. Using an 18-cm cell with low indicator concentrations (10 muM), this system achieves a precision and an accuracy of +/-2-3 muatm in the pCO(2) range of 200-500 muatm. The sensor also features a response time (99%) of only 2 min for low-level (pCO(2) measurements as a result of high CO(2) permeability of the amorphous fluoropolymer membrane. Field tests indicate that this new sensor is capable of handling both atmospheric and aquatic pCO(2) monitoring.

  8. Gas Membrane Sensor Technique for in-situ Downhole Detection of Gases Applied During Geological Storage of CO2

    Science.gov (United States)

    Zimmer, M.; Erzinger, J.; Kujawa, C.; Group, C.

    2008-12-01

    The geological storage of CO2 in deep saline aquifers is regarded as a possible technology for the reduction of anthropogenic greenhouse gases. However, comprehensive research is still needed to better understand the behaviour of CO2 during and after storage. Therefore, we developed and applied a new, innovative geochemical monitoring tool for the real time and in-situ determination of CO2 and other gases in the underground and in bore holes. The method uses a phase separating silicone membrane, permeable for gases, in order to separate gases dissolved in borehole fluids, water and brines. Argon is used as a carrier gas to conduct the collected gases through capillaries to the surface. Here, the gas phase is analyzed in real-time with a portable mass spectrometer for all permanent gases. In addition, gas samples may be collected for detailed investigations in the laboratory. Downhole extraction and on-line determination of gases dissolved in brines using this gas membrane sensor (GMS) technique was successful applied at the scientific CO2SINK test site in Ketzin, Germany (sandstone aquifer). GMSs together with temperature and pressure probes were installed in two approx. 700m deep observation holes, drilled in 50m and 100m distance from the CO2 injection well. Hydraulic pressure in the observation wells rose gradually during injection of CO2. Increasing reservoir gas concentrations of helium, hydrogen, methane, and nitrogen as well as the arrival of the added krypton tracer were determined shortly before the injected CO2 appeared. The breakthrough of CO2 into the observation well, in 50m distance, was recorded after 531.5 tons of CO2 were injected.

  9. Tunable Diode Laser Absorption Spectroscopy Sensor for Calibration Free Humidity Measurements in Pure Methane and Low CO2 Natural Gas.

    Science.gov (United States)

    Nwaboh, Javis Anyangwe; Pratzler, Sonja; Werhahn, Olav; Ebert, Volker

    2017-05-01

    We report a new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor for absolute measurements of H2O in methane, ethane, propane, and low CO2 natural gas. The sensor is operated with a 2.7 µm DFB laser, equipped with a high pressure single pass gas cell, and used to measure H2O amount of substance fractions in the range of 0.31-25 000 µmol/mol. Operating total gas pressures are up to 5000 hPa. The sensor has been characterized, addressing the traceability of the spectrometric results to the SI and the evaluation of the combined uncertainty, following the guide to the expression of uncertainty in measurement (GUM). The relative reproducibility of H2O amount of substance fraction measurements at 87 µmol/mol is 0.26% (0.23 µmol/mol). The maximum precision of the sensor was determined using a H2O in methane mixture, and found to be 40 nmol/mol for a time resolution of 100 s. This corresponds to a normalized detection limit of 330 nmol mol(-1)·m Hz(-1/2). The relative combined uncertainty of H2O amount fraction measurements delivered by the sensor is 1.2%.

  10. ACCURACY OF CO2 SENSORS

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2008-10-01

    Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.

  11. 新型结构CO2传感器的研究%Study on New-structure CO2 Gas Sensor

    Institute of Scientific and Technical Information of China (English)

    刘晓宁; 全宝富; 何月华; 吴玉军; 陈丽华

    2004-01-01

    介绍了一种新型管式结构固体电解质CO2传感器.该传感器是将溶胶–凝胶法制备的NASICON材料均匀涂敷在Al2O3陶瓷管上,烧结形成厚膜,加热丝穿过管内提供热量.在加热电流为180 mA,CO2浓度为(200~2000)×10-6时,管式元件灵敏度曲线的斜率达到60,比同电流下平面型元件的斜率高出14.2.35 d内,管式元件在1 000×10-6浓度下的漂移值为8.8 mV,与平面型元件的漂移值11.3 mV相比,显示了较好的稳定性.

  12. Research on Low Power Consumption Mini-type CO2 Gas Sensors%低功耗微型CO2传感器的研制

    Institute of Scientific and Technical Information of China (English)

    何月华; 全宝富; 王彪; 张春萍; 邱法斌

    2006-01-01

    制作了一种新型微型结构CO2传感器,该传感器采用Al2O3陶瓷片作为衬底,sol-gel法制备的固体电解质NASICON(sodium super ionic conductor)材料为离子导电层,复合碳酸盐Li2CO3-BaCO3(摩尔比为1:1.5)为敏感电极.该传感器在CO2浓度为(500~5 000)×10-6体积分数范围内表现出良好的敏感特性,灵敏度达到67.3 mV/decade(毫伏/10×10-6体积分数),并且功耗由原来的1.08 W降到0.72 W.微型元件的响应恢复时间分别为20 s和58 s.

  13. A Novel Solid State Non-Dispersive Infrared CO2 Gas Sensor Compatible with Wireless and Portable Deployment

    Directory of Open Access Journals (Sweden)

    Desmond Gibson

    2013-05-01

    Full Text Available This paper describes development of a novel mid-infrared light emitting diode (LED and photodiode (PD light source/detector combination and use within a non-dispersive infrared (NDIR carbon dioxide gas sensor. The LED/PD based NDIR sensor provides fast stabilisation time (time required to turn on the sensor from cold, warm up, take and report a measurement, and power down again ≈1 second, longevity (>15 years, low power consumption and low cost. Described performance is compatible with “fit and forget” wireless deployed sensors in applications such as indoor air quality monitoring/control & energy conservation in buildings, transport systems, horticultural greenhouses and portable deployment for safety, industrial and medical applications. Fast stabilisation time, low intrinsic power consumption and cycled operation offer typical energy consumption per measurement of mJ’s, providing extended operation using battery and/or energy harvesting strategies (measurement interval of ≈ 2 minutes provides >10 years operation from one AA battery. Specific performance data is provided in relation to measurement accuracy and noise, temperature performance, cross sensitivity, measurement range (two pathlength variants are described covering ambient through to 100% gas concentration, comparison with NDIR utilizing thermal source/pyroelectric light source/detector combination and compatibility with energy harvesting. Semiconductor based LED/PD processing together with injection moulded reflective optics and simple assembly provide a route to low cost high volume manufacturing.

  14. A novel solid state non-dispersive infrared CO2 gas sensor compatible with wireless and portable deployment.

    Science.gov (United States)

    Gibson, Desmond; MacGregor, Calum

    2013-05-29

    This paper describes development of a novel mid-infrared light emitting diode (LED) and photodiode (PD) light source/detector combination and use within a non-dispersive infrared (NDIR) carbon dioxide gas sensor. The LED/PD based NDIR sensor provides fast stabilisation time (time required to turn on the sensor from cold, warm up, take and report a measurement, and power down again ≈1 second), longevity (>15 years), low power consumption and low cost. Described performance is compatible with "fit and forget" wireless deployed sensors in applications such as indoor air quality monitoring/control & energy conservation in buildings, transport systems, horticultural greenhouses and portable deployment for safety, industrial and medical applications. Fast stabilisation time, low intrinsic power consumption and cycled operation offer typical energy consumption per measurement of mJ's, providing extended operation using battery and/or energy harvesting strategies (measurement interval of ≈ 2 minutes provides >10 years operation from one AA battery). Specific performance data is provided in relation to measurement accuracy and noise, temperature performance, cross sensitivity, measurement range (two pathlength variants are described covering ambient through to 100% gas concentration), comparison with NDIR utilizing thermal source/pyroelectric light source/detector combination and compatibility with energy harvesting. Semiconductor based LED/PD processing together with injection moulded reflective optics and simple assembly provide a route to low cost high volume manufacturing.

  15. A micro CO2 gas sensor based on sensing of pH-sensitive hydrogel swelling by means of a pressure sensor

    NARCIS (Netherlands)

    Herber, S.; Bomer, J.; Olthuis, W.; Bergveld, P.; Berg, van den A.

    2005-01-01

    In this paper a sensor is presented for the detection of carbon dioxide gas inside the stomach in order to diagnose gastrointestinal ischemia. The operational principle of the sensor is measuring the CO/sub 2/ induced pressure generation of a confined pH-sensitive hydrogel by means of a micro pressu

  16. Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design

    Science.gov (United States)

    Andrews, A. E.; Ryerson, T. B.; Peischl, J.; Parrish, D. D.; Trainer, M.; Tans, P. P.

    2011-12-01

    Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design A. Andrews, T. Ryerson, J. Peischl, D. Parrish, M. Trainer, P. Tans An extensive dataset of CO2 concentrations including enhancements in point and area source plumes is available from in situ measurements collected using the NOAA P-3 and NCAR Electra research aircraft during seven major field projects from 1999 through 2010. Research flights sampled emission plumes from coal-, oil-, and natural gas-fired electric utility power plants, industrial facilities, and urban areas. Plume sampling often included horizontal transects at several altitudes and multiple distances downwind. CO2 data from crosswind transects upwind and downwind, coupled with ancillary measurements of co-emitted nitric oxide, nitrogen dioxide and sulfur dioxide, along with plume location, and wind speed and direction permit unambiguous attribution and quantification of atmospheric plumes from individual sources. Certain point sources were revisited on multiple flights over the course of 1-2 month long field projects and on successive field projects spanning several years. Sampling occurred primarily in the summertime, daytime continental boundary layer, with some plume studies performed after dark and in the spring, fall, and winter seasons. The data provide rigorously calibrated, measurement-based constraints on the expected range of atmospheric CO2 plume enhancements that can be used to assess satellite sensor concepts. Crosswind near-field (~5 km) transects in the summer daytime mixed-layer downwind of the strongest point sources were characterized by peak plume CO2 mixing ratio enhancements >100 ppm above background for the 100-m spatial averages reported from the moving aircraft. On many flights, the aircraft tracked such emissions plumes beyond 150 km downwind, or up to 10 hours of transport time, until plume enhancements were indistinguishable from background variability in CO2

  17. Evaluation of a Prototype pCO2 Optical Sensor

    Science.gov (United States)

    Sanborn-Marsh, C.; Sutton, A.; Sabine, C. L.; Lawrence-Salvas, N.; Dietrich, C.

    2016-12-01

    Anthropogenic greenhouse gas emissions continue to rise, driving climate change and altering the ocean carbonate systems. Carbonate chemistry can be characterized by any two of the four parameters: pH, total alkalinity, dissolved inorganic carbon, and partial pressure of dissolved carbon dioxide gas (pCO2). To fully monitor these dynamic systems, researchers must deploy a more temporally and spatially comprehensive sensor network. Logistical challenges, such as the energy consumption, size, lifetime, depth range, and cost of pCO2 sensors have limited the network's reach so far. NOAA's Pacific Marine Environmental Laboratory has conducted assessment tests of a pCO2 optical sensor (optode), recently developed by Atamanchuk et al (2014). We hope to deploy this optode in the summer of 2017 on high-resolution moored profiler, along with temperature, salinity, and oxygen sensors. While most pCO2 optodes have energy consumptions of 3-10 W, this 36mm-diameter by 86mm-long instrument consumes a mere 7-80 mW. Initial testing showed that its accuracy varied within an absolute range of 2-75 μatm, depending on environmental conditions, including temperature, salinity, response time, and initial calibration. Further research independently examining the effects of each variable on the accuracy of the data will also be presented.

  18. QCM Sensors Based on PEI Films for CO2Detection

    Institute of Scientific and Technical Information of China (English)

    Guang-Zhong Xie; Ting Kang; Yong Zhou; Tao Xie; Hui-Ling Tai; Ya-Dong Jiang

    2015-01-01

    In this paper, quartz crystal microbalance (QCM) gas sensors coated with polyehtyleneimine (PEI) was utilized for carbon dioxide (CO2) detection. The sensing mechanism is based on the availability of reversible acid-base reactions between CO2 molecules and PEI at room temperature. The experimental results revealed that the PEI/starch sensor exhibited much higher sensitivity than that of pure PEI, and showed approximate linearity over a concentration region ranging from 500ppm to 8000ppm. The influence of humidity had also been investigated. Furthermore, the response and recovery time deceased as the operation temperatures increased. Finally, sensitivity loss after conservation for several days and reversibility of the sensors had been discussed.

  19. CO2 gas sensitivity of sputtered zinc oxide thin films

    Indian Academy of Sciences (India)

    P Samarasekara; N U S Yapa; N T R N Kumara; M V K Perera

    2007-04-01

    For the first time, sputtered zinc oxide (ZnO) thin films have been used as a CO2 gas sensor. Zinc oxide thin films have been synthesized using reactive d.c. sputtering method for gas sensor applications, in the deposition temperature range from 130–153°C at a chamber pressure of 8.5 mbar for 18 h. Argon and oxygen gases were used as sputtering and reactive gases, respectively. ZnO phase could be crystallized using a pure metal target of zinc. The structure of the films determined by means of X-ray diffraction method indicates that the zinc oxide single phase can be fabricated in this substrate temperature range. The sensitivity of the film synthesized at substrate temperature of 130°C is 2.17 in the presence of CO2 gas at a measuring temperature of 100°C.

  20. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

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

  1. Hydrogel-based sensor for CO2 measurements

    NARCIS (Netherlands)

    Herber, S.; Olthuis, W.; Bergveld, P.; Berg, van den A.

    2004-01-01

    A hydrogel-based sensor is presented for CO2 measurements. The sensor consists of a pressure sensor and porous silicon cover. A pH-sensitive hydrogel is confined between the two parts. Furthermore the porous cover contains a bicarbonate solution and a gaspermeable membrane. CO2 reacts with the solut

  2. CO2 Selective Potentiometric Sensor in Thick-film Technology

    Directory of Open Access Journals (Sweden)

    Ralf Moos

    2008-08-01

    Full Text Available A potentiometric sensor device based on screen-printed Nasicon films was investigated. In order to transfer the promising sensor concept of an open sodium titanate reference to thick film technology, “sodium-rich” and “sodium-poor” formulations were compared. While the “sodium-rich” composition was found to react with the ion conducting Nasicon during thermal treatment, the “sodium-poor” reference mixture was identified as an appropriate reference composition. Screen-printed sensor devices were prepared and tested with respect to CO2 response, reproducibility, and cross-interference of oxygen. Excellent agreement with the theory was observed. With the integration of a screen-printed heater, sensor elements were operated actively heated in a cold gas stream.

  3. CO2-Responsive Polymer-Functionalized Au Nanoparticles for CO2 Sensor.

    Science.gov (United States)

    Ma, Ying; Promthaveepong, Kittithat; Li, Nan

    2016-08-16

    Metallic nanoparticles (NPs) coated with stimuli-responsive polymers (SRPs) exhibit tunable optical properties responding to external stimuli and show promising sensing applications. We present a new CO2-responsive polymer, poly(N-(3-amidino)-aniline) (PNAAN), coated gold NPs (AuNPs) synthesized by directly reducing HAuCl4 with a CO2-responsive monomer N-(3-amidino)-aniline (NAAN). The amidine group of PNAAN can be protonated into a hydrophilic amidinium group by dissolved CO2 (dCO2). This induces the PNAAN to swell and detach from the AuNP surface, resulting in AuNP aggregation and color change. By monitoring the UV absorbance change of AuNPs, a sensitive dCO2 sensor with a linear range of 0.0132 to 0.1584 hPa and a limit of detection (LOD) of 0.0024 hPa is developed. This method shows dramatic improvement in sensitivity and convenience of sample preparation compared with the previously reported dCO2 sensor.

  4. Gas sensor

    Science.gov (United States)

    Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

    2014-09-09

    A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

  5. Evaluation and selection of sensing materials for carbon dioxide (CO2) sensor by molecular modeling

    NARCIS (Netherlands)

    Chen, X.P.; Wong, C.K.Y.; Yuan, C.A.; Zhang, G.Q.

    2011-01-01

    We report a molecular modeling study to evaluate and select conducting polymers (CPs) as the sensing materials of carbon dioxide (CO2) sensor. The interaction between polymer and gas and the adsorption of the gas molecules in the polymer matrix are investigated. Polymers considered for this work

  6. Evaluation and selection of sensing materials for carbon dioxide (CO 2) sensor by molecular modeling

    NARCIS (Netherlands)

    Chen, X.P.; Wong, C.K.Y.; Yuan, C.A.; Zhang, G.Q.

    2011-01-01

    We report a molecular modeling study to evaluate and select conducting polymers (CPs) as the sensing materials of carbon dioxide (CO2) sensor. The interaction between polymer and gas and the adsorption of the gas molecules in the polymer matrix are investigated. Polymers considered for this work

  7. Evaluation and selection of sensing materials for carbon dioxide (CO 2) sensor by molecular modeling

    NARCIS (Netherlands)

    Chen, X.P.; Wong, C.K.Y.; Yuan, C.A.; Zhang, G.Q.

    2011-01-01

    We report a molecular modeling study to evaluate and select conducting polymers (CPs) as the sensing materials of carbon dioxide (CO2) sensor. The interaction between polymer and gas and the adsorption of the gas molecules in the polymer matrix are investigated. Polymers considered for this work inc

  8. Evaluation and selection of sensing materials for carbon dioxide (CO2) sensor by molecular modeling

    NARCIS (Netherlands)

    Chen, X.P.; Wong, C.K.Y.; Yuan, C.A.; Zhang, G.Q.

    2011-01-01

    We report a molecular modeling study to evaluate and select conducting polymers (CPs) as the sensing materials of carbon dioxide (CO2) sensor. The interaction between polymer and gas and the adsorption of the gas molecules in the polymer matrix are investigated. Polymers considered for this work inc

  9. A Mobile Sensor Network to Map CO2 in Urban Environments

    Science.gov (United States)

    Lee, J.; Christen, A.; Nesic, Z.; Ketler, R.

    2014-12-01

    Globally, an estimated 80% of all fuel-based CO2 emissions into the atmosphere are attributable to cities, but there is still a lack of tools to map, visualize and monitor emissions to the scales at which emissions reduction strategies can be implemented - the local and urban scale. Mobile CO2 sensors, such as those attached to taxis and other existing mobile platforms, may be a promising way to observe and map CO2 mixing ratios across heterogenous urban environments with a limited number of sensors. Emerging modular open source technologies, and inexpensive compact sensor components not only enable rapid prototyping and replication, but also are allowing for the miniaturization and mobilization of traditionally fixed sensor networks. We aim to optimize the methods and technologies for monitoring CO2 in cities using a network of CO2 sensors deployable on vehicles and bikes. Our sensor technology is contained in a compact weather-proof case (35.8cm x 27.8cm x 11.8cm), powered independently by battery or by car, and includes the Li-Cor Li-820 infrared gas analyzer (Licor Inc, lincoln, NB, USA), Arduino Mega microcontroller (Arduino CC, Italy) and Adafruit GPS (Adafruit Technologies, NY, USA), and digital air temperature thermometer which measure CO2 mixing ratios (ppm), geolocation and speed, pressure and temperature, respectively at 1-second intervals. With the deployment of our sensor technology, we will determine if such a semi-autonomous mobile approach to monitoring CO2 in cities can determine excess urban CO2 mixing ratios (i.e. the 'urban CO2 dome') when compared to values measured at a fixed, remote background site. We present results from a pilot study in Vancouver, BC, where the a network of our new sensors was deployed both in fixed network and in a mobile campaign and examine the spatial biases of the two methods.

  10. Metal-CO2 Batteries on the Road: CO2 from Contamination Gas to Energy Source.

    Science.gov (United States)

    Xie, Zhaojun; Zhang, Xin; Zhang, Zhang; Zhou, Zhen

    2017-01-20

    Rechargeable nonaqueous metal-air batteries attract much attention for their high theoretical energy density, especially in the last decade. However, most reported metal-air batteries are actually operated in a pure O2 atmosphere, while CO2 and moisture in ambient air can significantly impact the electrochemical performance of metal-O2 batteries. In the study of CO2 contamination on metal-O2 batteries, it has been gradually found that CO2 can be utilized as the reactant gas alone; namely, metal-CO2 batteries can work. On the other hand, investigations on CO2 fixation are in focus due to the potential threat of CO2 on global climate change, especially for its steadily increasing concentration in the atmosphere. The exploitation of CO2 in energy storage systems represents an alternative approach towards clean recycling and utilization of CO2 . Here, the aim is to provide a timely summary of recent achievements in metal-CO2 batteries, and inspire new ideas for new energy storage systems. Moreover, critical issues associated with reaction mechanisms and potential directions for future studies are discussed.

  11. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Fauth, D.J.; Filburn, T.P. (University of Hartford, West Hartford, CT); Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

    2007-06-01

    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  12. Biosequestration of atmospheric CO2 and flue gas-containing CO2 by microalgae.

    Science.gov (United States)

    Cheah, Wai Yan; Show, Pau Loke; Chang, Jo-Shu; Ling, Tau Chuan; Juan, Joon Ching

    2015-05-01

    The unceasing rise of greenhouse gas emission has led to global warming and climate change. Global concern on this phenomenon has put forward the microalgal-based CO2 sequestration aiming to sequester carbon back to the biosphere, ultimately reducing greenhouse effects. Microalgae have recently gained enormous attention worldwide, to be the valuable feedstock for renewable energy production, due to their high growth rates, high lipid productivities and the ability to sequester carbon. The photosynthetic process of microalgae uses atmospheric CO2 and CO2 from flue gases, to synthesize nutrients for their growth. In this review article, we will primarily discuss the efficiency of CO2 biosequestration by microalgae species, factors influencing microalgal biomass productions, microalgal cultivation systems, the potential and limitations of using flue gas for microalgal cultivation as well as the bio-refinery approach of microalgal biomass.

  13. Sensor placement algorithm development to maximize the efficiency of acid gas removal unit for integrated gasifiction combined sycle (IGCC) power plant with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2012-01-01

    Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel

  14. TREATMENT OF NATURAL GAS BY ADSORPTION OF CO2

    Directory of Open Access Journals (Sweden)

    Kristýna Hádková

    2015-12-01

    Full Text Available Apart from burning, one of the possible uses of natural gas is as a fuel for motor vehicles. There are two types of fuel from natural gas — CNG (Compressed Natural Gas or LNG (Liquefied Natural Gas. Liquefaction of natural gas is carried out for transport by tankers, which are an alternative to long-distance gas pipelines, as well as for transport over short distance, using LNG as a fuel for motor vehicles. A gas adjustment is necessary to get LNG. As an important part of the necessary adjustment of natural gas to get LNG, a reduction of CO2 is needed. There is a danger of the carbon dioxide freezing during the gas cooling. This work deals with the testing of adsorption removal of CO2 from natural gas. The aim of these measurements was to find a suitable adsorbent for CO2 removal from natural gas. Two different types of adsorbents were tested: activated carbon and molecular sieve. The adsorption properties of the selected adsorbents were tested and compared. The breakthrough curves for CO2 for both adsorbents were measured. The conditions of the testing were estimated according to conditions at a gas regulation station — 4.0MPa pressure and 8 °C temperature. Natural gas was simulated by model gas mixture during the tests. The breakthrough volume was set as the gas volume passing through the adsorber up to the CO2 concentration of 300 ml/m3 in the exhaust gas. The thermal and pressure desorption of CO2 from saturated adsorbents were also tested after the adsorption.

  15. Gas condensate reservoir characterisation for CO2 geological storage

    Science.gov (United States)

    Ivakhnenko, A. P.

    2012-04-01

    During oil and gas production hydrocarbon recovery efficiency is significantly increased by injecting miscible CO2 gas in order to displace hydrocarbons towards producing wells. This process of enhanced oil recovery (EOR) might be used for the total CO2 storage after complete hydrocarbon reservoir depletion. This kind of potential storage sites was selected for detailed studies, including generalised development study to investigate the applicability of CO2 for storages. The study is focused on compositional modelling to predict the miscibility pressures. We consider depleted gas condensate field in Kazakhstan as important target for CO2 storage and EOR. This reservoir being depleted below the dew point leads to retrograde condensate formed in the pore system. CO2 injection in the depleted gas condensate reservoirs may allow enhanced gas recovery by reservoir pressurisation and liquid re-vaporisation. In addition a number of geological and petrophysical parameters should satisfy storage requirements. Studied carbonate gas condensate and oil field has strong seal, good petrophysical parameters and already proven successful containment CO2 and sour gas in high pressure and high temperature (HPHT) conditions. The reservoir is isolated Lower Permian and Carboniferous carbonate platform covering an area of about 30 km. The reservoir contains a gas column about 1.5 km thick. Importantly, the strong massive sealing consists of the salt and shale seal. Sour gas that filled in the oil-saturated shale had an active role to form strong sealing. Two-stage hydrocarbon saturation of oil and later gas within the seal frame were accompanied by bitumen precipitation in shales forming a perfect additional seal. Field hydrocarbon production began three decades ago maintaining a strategy in full replacement of gas in order to maintain pressure of the reservoir above the dew point. This was partially due to the sour nature of the gas with CO2 content over 5%. Our models and

  16. 一种基于双固体电解质的CO2传感器%A New Carbon Dioxide Gas Sensor Based on Solid Bielectrolyte

    Institute of Scientific and Technical Information of China (English)

    周会珠; 王岭; 王福先; 戴磊; 洪彦若

    2007-01-01

    以Nasicon结合的Na-β-alumina作为固体电解质,BaCO3-Na2CO3(44:56)作为辅助电极制备了CO2传感器并检验了其性能.结果表明:在618~947 K范围内测得的传感器电动势与CO2浓度之间成良好的线性关系,符合能斯特关系,反应的电子转移数接近2.实验了水蒸汽,O2,NO2和SO2对CO2测定的影响,结果表明,O2、水蒸汽对CO2传感器性能没有明显的影响;低于100×10-6NO2对传感器响应也没有造成干扰;当共存SO2高于1.7×10-6时由于在辅助电极和电解质表面生成Na2SO4而严重影响其性能.

  17. Potential for the Use of Wireless Sensor Networks for Monitoring of CO2 Leakage Risks

    Science.gov (United States)

    Pawar, R.; Illangasekare, T. H.; Han, Q.; Jayasumana, A.

    2015-12-01

    Storage of supercritical CO2 in deep saline geologic formation is under study as a means to mitigate potential global climate change from green house gas loading to the atmosphere. Leakage of CO2 from these formations poses risk to the storage permanence goal of 99% of injected CO2 remaining sequestered from the atmosphere,. Leaked CO2 that migrates into overlying groundwater aquifers may cause changes in groundwater quality that pose risks to environmental and human health. For these reasons, technologies for monitoring, measuring and accounting of injected CO2 are necessary for permitting of CO2 sequestration projects under EPA's class VI CO2 injection well regulations. While the probability of leakage related to CO2 injection is thought to be small at characterized and permitted sites, it is still very important to protect the groundwater resources and develop methods that can efficiently and accurately detect CO2 leakage. Methods that have been proposed for leakage detection include remote sensing, soil gas monitoring, geophysical techniques, pressure monitoring, vegetation stress and eddy covariance measurements. We have demonstrated the use of wireless sensor networks (WSN) for monitoring of subsurface contaminant plumes. The adaptability of this technology for leakage monitoring of CO2 through geochemical changes in the shallow subsurface is explored. For this technology to be viable, it is necessary to identify geochemical indicators such as pH or electrical conductivity that have high potential for significant change in groundwater in the event of CO2 leakage. This talk presents a conceptual approach to use WSNs for CO2 leakage monitoring. Based on our past work on the use of WSN for subsurface monitoring, some of the challenges that need to be over come for this technology to be viable for leakage detection will be discussed.

  18. CO2 Utilization and Storage in Shale Gas Reservoirs

    Science.gov (United States)

    Schaef, T.; Glezakou, V.; Owen, T.; Miller, Q.; Loring, J.; Davidson, C.; McGrail, P.

    2013-12-01

    Surging natural gas production from fractured shale reservoirs and the emerging concept of utilizing anthropogenic CO2 for secondary recovery and permanent storage is driving the need for understanding fundamental mechanisms controlling gas adsorption and desorption processes, mineral volume changes, and impacts to transmissivity properties. Early estimates indicate that between 10 and 30 gigatons of CO2 storage capacity may exist in the 24 shale gas plays included in current USGS assessments. However, the adsorption of gases (CO2, CH4, and SO2) is not well understood and appears unique for individual clay minerals. Using specialized experimental techniques developed at PNNL, pure clay minerals were examined at relevant pressures and temperatures during exposure to CH4, CO2, and mixtures of CO2-SO2. Adsorbed concentrations of methane displayed a linear behavior as a function of pressure as determined by a precision quartz crystal microbalance. Acid gases produced differently shaped adsorption isotherms, depending on temperature and pressure. In the instance of kaolinite, gaseous CO2 adsorbed linearly, but in the presence of supercritical CO2, surface condensation increased significantly to a peak value before desorbing with further increases in pressure. Similarly shaped CO2 adsorption isotherms derived from natural shale samples and coal samples have been reported in the literature. Adsorption steps, determined by density functional theory calculations, showed they were energetically favorable until the first CO2 layer formed, corresponding to a density of ~0.35 g/cm3. Interlayer cation content (Ca, Mg, or Na) of montmorillonites influenced adsorbed gas concentrations. Measurements by in situ x-ray diffraction demonstrate limited CO2 diffusion into the Na-montmorillonite interlayer spacing, with structural changes related to increased hydration. Volume changes were observed when Ca or Mg saturated montmorillonites in the 1W hydration state were exposed to

  19. A rate-based transcutaneous CO2 sensor for noninvasive respiration monitoring

    OpenAIRE

    Chatterjee, M; Ge, X; Kostov, Y; Luu, P; Tolosa, L; Woo, H.; Viscardi, R; Falk, S; R. Potts; G Rao

    2015-01-01

    The pain and risk of infection associated with invasive blood sampling for blood gas measurements necessitate the search for reliable noninvasive techniques. In this work we developed a novel rate-based noninvasive method for a safe and fast assessment of respiratory status. A small sampler was built to collect the gases diffusing out of the skin. It was connected to a CO2 sensor through gas-impermeable tubing. During a measurement, the CO2 initially present in the sampler was first removed b...

  20. CO2-emissions from Norwegian oil and gas extraction

    OpenAIRE

    2015-01-01

    Emissions from oil and gas extraction matter for the lifecycle emissions of fossil fuels, and account for significant shares of domestic emissions in many fossil fuel exporting countries. In this study we investigate empirically the driving forces behind CO2-emission intensities of Norwegian oil and gas extraction, using detailed field-specific data that cover all Norwegian oil and gas activity. We find that emissions per unit extraction increase significantly as a field’s extraction declines...

  1. CO2-emissions form Norwegian oil and gas extraction

    OpenAIRE

    2015-01-01

    Emissions from oil and gas extraction matter for the lifecycle emissions of fossil fuels, and account for significant shares of domestic emissions in many fossil fuel exporting countries. In this study we investigate empirically the driving forces behind CO2-emission intensities of Norwegian oil and gas extraction, using detailed field-specific data that cover all Norwegian oil and gas activity. We find that emissions per unit extraction increase significantly as a field's extraction declines...

  2. A Sulfur Hexafluoride Sensor Using Quantum Cascade and CO2 Laser-Based Photoacoustic Spectroscopy

    Directory of Open Access Journals (Sweden)

    Helion Vargas

    2010-10-01

    Full Text Available The increase in greenhouse gas emissions is a serious environmental problem and has stimulated the scientific community to pay attention to the need for detection and monitoring of gases released into the atmosphere. In this regard, the development of sensitive and selective gas sensors has been the subject of several research programs. An important greenhouse gas is sulphur hexafluoride, an almost non-reactive gas widely employed in industrial processes worldwide. Indeed it is estimated that it has a radiative forcing of 0.52 W/m2. This work compares two photoacoustic spectrometers, one coupled to a CO2 laser and another one coupled to a Quantum Cascade (QC laser, for the detection of SF6. The laser photoacoustic spectrometers described in this work have been developed for gas detection at small concentrations. Detection limits of 20 ppbv for CO2 laser and 50 ppbv for quantum cascade laser were obtained.

  3. Determining CO2 storage potential during miscible CO2 enhanced oil recovery: Noble gas and stable isotope tracers

    Science.gov (United States)

    Shelton, Jenna L.; McIntosh, Jennifer C.; Hunt, Andrew; Beebe, Thomas L; Parker, Andrew D; Warwick, Peter; Drake, Ronald; McCray, John E.

    2016-01-01

    Rising atmospheric carbon dioxide (CO2) concentrations are fueling anthropogenic climate change. Geologic sequestration of anthropogenic CO2 in depleted oil reservoirs is one option for reducing CO2 emissions to the atmosphere while enhancing oil recovery. In order to evaluate the feasibility of using enhanced oil recovery (EOR) sites in the United States for permanent CO2 storage, an active multi-stage miscible CO2flooding project in the Permian Basin (North Ward Estes Field, near Wickett, Texas) was investigated. In addition, two major natural CO2 reservoirs in the southeastern Paradox Basin (McElmo Dome and Doe Canyon) were also investigated as they provide CO2 for EOR operations in the Permian Basin. Produced gas and water were collected from three different CO2 flooding phases (with different start dates) within the North Ward Estes Field to evaluate possible CO2 storage mechanisms and amounts of total CO2retention. McElmo Dome and Doe Canyon were sampled for produced gas to determine the noble gas and stable isotope signature of the original injected EOR gas and to confirm the source of this naturally-occurring CO2. As expected, the natural CO2produced from McElmo Dome and Doe Canyon is a mix of mantle and crustal sources. When comparing CO2 injection and production rates for the CO2 floods in the North Ward Estes Field, it appears that CO2 retention in the reservoir decreased over the course of the three injections, retaining 39%, 49% and 61% of the injected CO2 for the 2008, 2010, and 2013 projects, respectively, characteristic of maturing CO2 miscible flood projects. Noble gas isotopic composition of the injected and produced gas for the flood projects suggest no active fractionation, while δ13CCO2 values suggest no active CO2dissolution into formation water, or mineralization. CO2 volumes capable of dissolving in residual formation fluids were also estimated along with the potential to store pure-phase supercritical CO2. Using a combination

  4. Capture of CO2 From Recirculating Flue Gas Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Ochs, Thomas L.

    2003-01-01

    The possible need for an economical method for the separation of CO2 from flue gas adds a new set of challenges to power plant design, construction, operation, and maintenance. Many of the new requirements of CO2 separation are similar in nature to those addressed by the mature chemical engineering processes used in petroleum refining and industrial chemical production. Chemical engineering processes are regularly used to separate heterogeneous vapors in processes such as the fractionation of hydrocarbons or the separation of the components of air. This paper addresses the application of chemical engineering processes to the mixtures of gases and vapors found in the flue gas of recirculating boilers. Adaptation of these techniques can lead to a reduction in the energy required to capture CO2.

  5. Development of in situ CO2 and pH sensor for AUVs and ROVs

    Science.gov (United States)

    Nakano, Yoshiyuki; Kimoto, Hideshi; Miwa, Tetsuya; Yoshida, Hiroshi

    2013-04-01

    Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been developing two-type autonomous underwater vehicles (AUVs): a cruising AUV and a working AUV, since October 2010. These vehicles will perform carbon dioxide (CO2) and pH observations to explore hydrothermal plume on seabed mineral resources and to monitor a leak of CO2 in carbon capture and storage (CCS) up to depth of 3,000 meters. We here have been developing the compact in situ CO2 and pH sensor (Hybrid CO2-pH sensor: HCS) for the AUVs to obtain vertical and horizontal distributions of CO2 and pH. The HCS consists of an aluminum pressure housing (diameter 84 mm, length 570 mm, weight 4 kg) and an acrylic silicon-oil filled, pressure-compensated vessel (diameter 90 mm, length 355 mm, weight 2 kg) containing valves and pump unit. The HCS is also useful for the observation by remotely operated vehicles (ROVs). The measured data were transmitted to the AUVs or ROVs by serial communications. We can monitor the data of in situ pCO2, pH and so on in real time on board. The measurement principle for the CO2 sensor is based on spectrophotometry. The pCO2 is calculated from the optical absorbance of the pH indicator solution equilibrated with CO2 in seawater through a gas permeable membrane. On the other hand, we adopt potentiometric analysis using original glass and reference electrodes as a pH sensor because of the most commonly used technique for sea water pH measurements and high-speed response (within 20 seconds). From simultaneously measured data of in situ pCO2 and pH, we can also calculate dissolved inorganic carbon (DIC) and total alkalinity (TA) as other carbonate species in the ocean. The resolutions of HCS are 1 μatm for pCO2 and 0.001 pH. In the laboratory experiment, the HCS obtained precisions within 3 μatm and within 0.01 pH, respectively. Our first in situ observational test of the HSC with cruising AUV was made in the coast of the Japan Sea last August. And also first in situ test

  6. Measuring NO, NO2, CO2 and O3 with low-cost sensors

    Science.gov (United States)

    Müller, Michael; Graf, Peter; Hüglin, Christoph

    2017-04-01

    Inexpensive sensors measuring ambient gas concentrations can be integrated in sensor units forming dense sensor networks. The utilized sensors have to be sufficiently accurate as the value of such networks directly depends on the information they provide. Thus, thorough testing of sensors before bringing them into service and the application of effective strategies for performance monitoring and adjustments during service are key elements for operating the low-cost sensors that are currently available on the market. We integrated several types of low-cost sensors into sensor units (Alphasense NO2 B4/B42F/B43F, Alphasense NO B4, SensAir CO2 LP8, Aeroqual O3 SM50), run them in the field next to instruments of air quality monitoring stations and performed tests in the laboratory. The poster summarizes our findings regarding the achieved sensor accuracy, methods to improve sensor performance as well as strategies to monitor the current state of the sensor (drifts, sensitivity) within a sensor network.

  7. A Catalytic Sensor for Measurement of Radical Density in CO2 Plasmas

    Directory of Open Access Journals (Sweden)

    Alenka Vesel

    2012-11-01

    Full Text Available A catalytic sensor for the measurement of radical density in weakly ionized CO2 plasmas, created in a low-pressure electrodeless discharge, is presented. The CO2 plasma was created in a 4 cm wide borosilicate glass tube inside a copper coil connected to a radio frequency generator operating at 27.12 MHz with a nominal power of 250 W. The dissociation fraction of the CO2 molecules was measured in the early afterglow at pressures ranging from 10 Pa to 100 Pa, and at distances of up to 35 cm along the gas stream from the glowing plasma. The radical density peaked (2 × 1020 m–3 at 80 Pa. The density quickly decreased with increasing distance from the glowing plasma despite a rather large drift velocity. The dissociation fraction showed similar behavior, except that the maximum was obtained at somewhat lower pressure. The results were explained by rather intense surface recombination of radicals.

  8. Gas monitoring during the CO2 back production field test at the Ketzin pilot site

    Science.gov (United States)

    Szizybalski, Alexandra; Zimmer, Martin; Kujawa, Christian; Erzinger, Jörg

    2015-04-01

    The GFZ German Research Centre for Geosciences operates Europe's first on-shore CO2 storage site in Ketzin, a small town near Berlin. From June 2008 until August 2013 about 67 kt of CO2 were injected into Upper Triassic sandstones in 630 to 650 m depth. The injection phase ended with an experiment to evaluate the influence of additives on CO2 storage. During this experiment 32 t N2 and 613 t CO2 were co-injected into the borehole over a period of 25 days followed by the final injection of 66 t pure CO2. At the beginning of the experiment 10,000 l (10 Nm3) Kr were pumped into the borehole, to separate the previous pure CO2 and the CO2-N2 mixture. For the same reason, CO2 with a different isotopic composition (δ13C = -3.4±0.2o instead of δ13C = -30.6±0.4) was used for the first 548 t of the total 613 t. To demonstrate that the stored CO2 is retrievable a field test was carried out in October 2014 during a period of two weeks. Of interest, in this context, is the composition of the back-produced gas which delivers key information on possible interactions between the CO2, formation fluid and rocks. In total 240 t of gas were produced via the former injection well. The flow rates ranged between 800 and 3,200 kg gas/h. The gas was sampled after the gas/water separator and continuously analysed using a mass spectrometer, a gas chromatograph and a photoacoustic sensor, thus covering all gas components and concentrations. In addition, gas samples were collected for stable carbon isotopes investigations in the laboratory. Preliminary results show that the produced gas consists of > 97% CO2 plus mainly N2. The N2 was detected from the beginning, although the injection in 2013 ended with pure CO2. The N2 concentration decreased from about 3% to 1% during the two weeks of the experiment. In addition to these major components CH4, CO and H2 (up to 0.01%) as well as Kr and SF6 (up to 0.001%, both were used as tracers in 2013) were detected. The gas composition of natural

  9. Assisting Gas Optimization in CO2 Laser Welding

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    1996-01-01

    High quality laser welding is achieved under the condition of optimizing all process parameters. Assisting gas plays an important role for sound welds. In the conventional welding process assisting gas is used as a shielding gas to prevent that the weld seam oxidates. In the laser welding process...... assisting gas is also needed to control the laser induced plasma.Assisting gas is one of the most important parameters in the laser welding process. It is responsible for obtaining a quality weld which is characterized by deep penetration, no interior imperfections, i.e. porosity, no crack, homogeneous seam...... are applied with three different flow rates for each of the gases. A number of systematic laboratory experiments is carried out by employing various experimental designs, 33 and 32 Factorial Design. In the experiments a CO2 laser is used to weld thin sheets of mild steel. The welding specimens are evaluated...

  10. Study on the Characteristics of Ag Doped CuO-BaTiO3 CO2 Sensors

    Directory of Open Access Journals (Sweden)

    Jinhuai Liu

    2002-09-01

    Full Text Available In this paper the characteristics of a CuO-BaTiO3 based CO2 gas sensor was investigated. The sensitivity of the CuO-BaTiO3 based CO2 sensor was influenced by doping various metal elements such as Au, Ag, Pt, Pd, Ce, Mg, Sr, La, Zn, Fe and Bi, which were added as a pure metal or in the form of metal oxides. It was found that Ag is the most suitable additive among all substances tested. The Ag-doped CO2 gas sensor has better sensitivity and lower operating temperature, with a detection concentration range of from 100 ppm to 10%. The sensor also shows good stability.

  11. A low-cost sensor for high density urban CO2 monitoring

    Science.gov (United States)

    Zeng, N.; Martin, C.

    2015-12-01

    The high spatial-termporal variability of greenhouse gases and other pollution sources in an urban environment can not be easily resolved with current high-accuracy but expensive instruments. We have tested a small, low-cost NDIR CO2 sensor designed for potential use. It has a manufacturer's specified accuracy of +- 30 parts per million (ppm). However, initial results running parallel with a research-grade greenhouse gas analyzer have shown that the absolute accuracy of the sensor is within +-5ppm, suggesting their utility for sensing ambient air variations in carbon dioxide. Through a multivariate analysis, we have determined a correction procedure that when accounting for environmental temperature, humidity, air pressure, and the device's span and offset, we can further increase the accuracy of the collected data. We will show results from rooftop measurements over a period of one year and CO2 tracking data in the Washington-Baltimore Metropolitan area.

  12. CO2-H2 gas separation by physical adsorption

    Science.gov (United States)

    Maiga, Sidi; Mbaye, Mamadou; Gatica, Silvina

    2011-04-01

    In the advancement of Hydrogen-based economy, the efficient production of H2 represents an issue for commercial applications. Regardless of the method, H2 purification ultimately equates to a CO2 removal process. Gas separation by adsorption can be accomplished by three basic physical mechanisms: equilibrium, steric and kinetic. Equilibrium mechanisms are based on the strength of the attraction of the gases to the substrate; the kinetic mechanisms are those based on the differences in the rates of adsorption and/or transport of the gas on and through the substrate; and the steric mechanisms are based on the incompatibility between the size or shape of the pores in the substrate and those of the adsorbate gas molecules. Many materials have been used for this purpose during the past half century, including carbon nanotubes (NTs), activated carbons and zeolites. Within the arena of gas separations, ``Metal-Organic Frameworks'' (MOFs) or Carbon Nanohorns (CNHs) are promising materials. We have studied the energy space distribution of CO2and H2 in MOFs and CNHs and found that based on the energetics the materials may be used for gas separation processes. Acknowledgment is made to the Donors of the American Chemical Society Petroleum Research Fund and to the National Science Foundation under Grant No. DMR-1006010 for partial support of this research.

  13. Modeling CO2 air dispersion from gas driven lake eruptions

    Science.gov (United States)

    Chiodini, Giovanni; Costa, Antonio; Rouwet, Dmitri; Tassi, Franco

    2016-04-01

    The most tragic event of gas driven lake eruption occurred at Lake Nyos (Cameroon) on 21 August 1986, when a dense cloud of CO2 suffocated more than 1700 people and an uncounted number of animals in just one night. The event stimulated a series of researches aimed to understand gas origins, gas release mechanisms and strategies for gas hazard mitigation. Very few studies have been carried out for describing the transport of dense CO2 clouds in the atmosphere. Although from a theoretical point of view, gas dispersion can be fully studied by solving the complete equations system for mass, momentum and energy transport, in actual practice, different simplified models able to describe only specific phases or aspects have to be used. In order to simulate dispersion of a heavy gas and to assess the consequent hazard we used a model based on a shallow layer approach (TWODEE2). This technique which uses depth-averaged variables to describe the flow behavior of dense gas over complex topography represents a good compromise between the complexity of computational fluid dynamic models and the simpler integral models. Recently the model has been applied for simulating CO2 dispersion from natural gas emissions in Central Italy. The results have shown how the dispersion pattern is strongly affected by the intensity of gas release, the topography and the ambient wind speed. Here for the first time we applied TWODEE2 code to simulate the dispersion of the large CO2 clouds released by limnic eruptions. An application concerns the case of the 1986 event at lake Nyos. Some difficulties for the simulations were related to the lack of quantitative information: gas flux estimations are not well constrained, meteorological conditions are only qualitatively known, the digital model of the terrain is of poor quality. Different scenarios were taken into account in order to reproduce the qualitative observations available for such episode. The observations regard mainly the effects of gas on

  14. MEMS CHIP CO2 SENSOR FOR BUILDING SYSTEMS INTEGRATION

    Energy Technology Data Exchange (ETDEWEB)

    Anton Carl Greenwald

    2005-09-14

    The objective of this research was to develop an affordable, reliable sensor to enable demand controlled ventilation (DCV). A significant portion of total energy consumption in the United States is used for heating or air conditioning (HVAC) buildings. To assure occupant safety and fresh air levels in large buildings, and especially those with sealed windows, HVAC systems are frequently run in excess of true requirements as automated systems cannot now tell the occupancy level of interior spaces. If such a sensor (e.g. thermostat sized device) were available, it would reduce energy use between 10 and 20% in such buildings. A quantitative measure of ''fresh air'' is the concentration of carbon dioxide (CO{sub 2}) present. An inert gas, CO{sub 2} is not easily detected by chemical sensors and is usually measured by infrared spectroscopy. Ion Optics research developed a complete infrared sensor package on a single MEMS chip. It contains the infrared (IR) source, IR detector and IR filter. The device resulting from this DOE sponsored research has sufficient sensitivity, lifetime, and drift rate to meet the specifications of commercial instrument manufacturers who are now testing the device for use in their building systems.

  15. Evaluation of Mars CO2 Capture and Gas Separation Technologies

    Science.gov (United States)

    Muscatello, Anthony C.; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

    2011-01-01

    Recent national policy statements have established that the ultimate destination of NASA's human exploration program is Mars. In Situ Resource Utilization (ISRU) is a key technology required to ,enable such missions and it is appropriate to review progress in this area and continue to advance the systems required to produce rocket propellant, oxygen, and other consumables on Mars using the carbon dioxide atmosphere and other potential resources. The Mars Atmospheric Capture and Gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure CO2 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as well. To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from unreacted carbon oxides (C02-CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3)/carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include' freezers, selective membranes, selective solvents, polymeric sorbents

  16. Lorentz Angle Measurement for CO2/Isobutane Gas Mixtures

    CERN Document Server

    Hoshina, K; Khalatyan, N S; Nitoh, O; Okuno, H; Kato, Y; Kobayashi, M; Kurihara, Y; Kuroiwa, H; Nakamura, Y; Sakieda, K; Suzuki, Y; Watanabe, T

    2002-01-01

    We have developed a Lorentz angle measurement system for cool gas mixtures in the course of our R&D for a proposed JLC central drift chamber (JLC-CDC). The measurement system is characterized by the use of two laser beams to produce primary electrons and flash ADCs to read their signals simultaneously. With this new system, we have measured Lorentz angles for CO2/isobutane gas mixtures with different proportions (95:5, 90:10, and 85:15), varying drift field from 0.6 to 2.0 kV/cm and magnetic field up to 1.5 T. The results of the measurement are in good agreement with GARFIELD/MAGBOLTZ simulations.

  17. Reusable In Situ AirCore System for CO2 and Trace Gas Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel design for an in situ atmospheric sensor for CO2 and trace gases is proposed. The sensor, named AirCore, provides the advantages of existing in situ sensors...

  18. Assessment of a new prototype hydrogel CO2 sensor; comparison with air tonometry

    NARCIS (Netherlands)

    Steege, ter W.F.; Herber, S.; Olthuis, W.; Bergveld, P.; Berg, van den A.; Kolkman, J.

    2007-01-01

    a>Abstract a>Objective Gastrointestinal ischemia is always accompanied by an increased luminal CO2. Currently, air tonometry is used to measure luminal CO2. To improve the response time a new sensor was developed, enabling continuous CO2 measurement. It consists of a pH-sensitive hydrogel which swe

  19. Response of CO2 Concentration in Andisol to Rainfall Events by Using Buried Tubing Gas Monitoring System

    Science.gov (United States)

    Endo, Toshifumi; Tokida, Takeshi; Imoto, Hiromi; Nishimura, Taku; Miyazaki, Tsuyoshi

    For the purpose of continuous soil CO2 gas monitoring, gas permeable resins were evaluated. Among polytetrafluoroethylen (PTFE), polyfluoroethylene propylene (PFEP) and silicone, the silicone rubber tube had highest permeability for oxygen gas. Buried Tubing Gas Monitoring System (BT-GMS) consisting of silicone rubber tube connected to a Non-diffuse infrared (NDIR) -CO2 gas and galvanic cell O2 gas sensors were constructed, and buried into an Andisol upland field at a depth of 20cm. Thermo-couples and EC-5 soil moisture sensors were inserted into 10 and 20cm deep layers. Soil CO2 gas concentration, temperature and moisture were continuously monitored for 5 months. Soil CO2 concentration was sensitive to rainfall events and soil moisture change. Responses were keen during summer until early autumn when soil temperature was higher than 20°C. Then, when soil temperature got lower the response tended to be dull. This suggested quick CO2 gas concentration change following a rainfall event was mostly due to enhancement in soil respiration with soil moisture rise.

  20. A PILOT STUDY OF THE ACCURACY OF CO2 SENSORS IN COMMERCIAL BUILDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William; Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2007-09-01

    Carbon dioxide (CO2) sensors are often deployed in commercial buildings to obtain CO2 data that are used to automatically modulate rates of outdoor air supply. The goal is to keep ventilation rates at or above design requirements and to save energy by avoiding ventilation rates exceeding design requirements. However, there have been many anecdotal reports of poor CO2 sensor performance in actual commercial building applications. This study evaluated the accuracy of 44 CO2 sensors located in nine commercial buildings to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. CO2 measurement errors varied widely and were sometimes hundreds of parts per million. Despite its small size, this study provides a strong indication that the accuracy of CO2 sensors, as they are applied and maintained in commercial buildings, is frequently less than needed to measure typical values of maximum one-hour-average indoor-outdoor CO2 concentration differences with less than a 20percent error. Thus, we conclude that there is a need for more accurate CO2 sensors and/or better sensor maintenance or calibration procedures.

  1. Economic Comparison of Three Gas Separation Technologies for CO2 Capture from Power Plant Flue Gas

    Institute of Scientific and Technical Information of China (English)

    YANG Hongjun; FAN Shuanshi; LANG Xuemei; WANG Yanhong; NIE Jianghua

    2011-01-01

    Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three technologies are analyzed and compared.The cost for chemical absorption is mainly from $30 to $60 per ton(based on CO2 avoided),while the minimum value is $10 per ton(based on CO2 avoided).As for membrane separation and pressure swing adsorption,the costs are $50 to $78 and $40 to $63 per ton(based on CO2 avoided),respectively.Measures are proposed to reduce the cost of the three technologies.For CO2 capture and storage process,the CO2 recovery and purity should be greater than 90%.Based on the cost,recovery,and purity,it seems that chemical absorption is currently the most cost-effective technology for CO2 capture from flue gas from power plants.However,membrane gas separation is the most promising alternative approach in the future,provided that membrane performance is further improved.

  2. LIBS Sensor for Sub-surface CO2 Leak Detection in Carbon Sequestration

    Directory of Open Access Journals (Sweden)

    Jinesh JAIN

    2017-07-01

    Full Text Available Monitoring carbon sequestration poses numerous challenges to the sensor community. For example, the subsurface environment is notoriously harsh, with large potential mechanical, thermal, and chemical stresses, making long-term stability and survival a challenge to any potential in situ monitoring method. Laser induced breakdown spectroscopy (LIBS has been demonstrated as a promising technology for chemical monitoring of harsh environments and hard to reach places. LIBS has a real- time monitoring capability and can be used for the elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of the probe design and the use of fiber- optics has made LIBS particularly suited for remote measurements. The paper focuses on developing a LIBS instrument for downhole high-pressure, high-temperature brine experiments, where CO2 leakage could result in changes in the trace mineral composition of an aquifer. The progress in fabricating a compact, robust, and simple LIBS sensor for widespread subsurface leak detection is presented.

  3. Polymer blend membranes for CO2 separation from natural gas

    Science.gov (United States)

    Mukhtar, H.; Mannan, H. A.; Minh, D.; Nasir, R.; Moshshim, D. F.; Murugesan, T.

    2016-06-01

    Polymeric membranes are dominantly used in industrial gas separation membrane processes. Enhancement in membranes permeability and/or selectivity is a key challenge faced by membrane researchers. The current work represents the effect of poyetherimide blending on separation performance of polysulfone membranes. Polysulfone/poyetherimide (PSF/PEI) blend flat sheet dense membranes were synthesized and tested for permeation analysis of CO2 and CH4 gases at 6, 8 and 10 bar pressure and 25oC temperature. Morphology and thermal properties of membranes were characterized by field emission scanning electron microscope (FESEM) and thermo gravimetric analysis (TGA) respectively. Blend membranes were dense and homogeneous as deduced from FESEM analysis. Thermal stability of synthesized blend membranes was maintained by blending with PEI as characterized by TGA results. Decrease in permeability of both gases was observed by the addition of PEI due to rigidity of PEI chains. Additionally, selectivity of synthesized blend membranes was enhanced by blending PEI and blend membranes show improved selectivity over pure PSF membrane. This new material has the capability to be used as gas separation membrane material.

  4. AirCore Reusable InSitu Sampler for CO2 and Trace Gas Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel design for an in situ air sampling sensor for CO2 and trace gases is proposed. The sensor, named AirCore, provides the advantages of existing in situ...

  5. Real-time breath gas analysis of CO and CO2 using an EC-QCL

    Science.gov (United States)

    Ghorbani, Ramin; Schmidt, Florian M.

    2017-05-01

    Real-time breath gas analysis is a promising, non-invasive tool in medical diagnostics, and well-suited to investigate the physiology of carbon monoxide (CO), a potential biomarker for oxidative stress and respiratory diseases. A sensor for precise, breath-cycle resolved, simultaneous detection of exhaled CO (eCO) and carbon dioxide (eCO2) was developed based on a continuous wave, external-cavity quantum cascade laser (EC-QCL), a low-volume multi-pass cell and wavelength modulation spectroscopy. The system achieves a noise-equivalent (1σ) sensitivity of 8.5 × 10-8 cm-1 Hz-1/2 and (2σ) detection limits of 9 ± 2 ppbv and 650 ± 7 ppmv at 0.14 s spectrum acquisition time for CO and CO2, respectively. Integration over 15 s yields a precision of 0.6 ppbv for CO. The fact that the eCO2 expirograms measured by capnography and laser spectroscopy have essentially identical shape confirms true real-time detection. It is found that the individual eCO exhalation profiles from healthy non-smokers have a slightly different shape than the eCO2 profiles and exhibit a clear dependence on exhalation flow rate and breath-holding time. Detection of indoor air CO and broadband breath profiling across the 93 cm-1 mode-hop-free tuning range of the EC-QCL are also demonstrated.

  6. Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

    Science.gov (United States)

    Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.

    2014-12-01

    A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.

  7. Accuracy of CO2 sensors in commercial buildings: a pilotstudy

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2006-10-01

    Carbon dioxide (CO{sub 2}) sensors are often deployed in commercial buildings to obtain CO{sub 2} data that are used to automatically modulate rates of outdoor air supply. The goal is to keep ventilation rates at or above code requirements, but to also to save energy by avoiding over ventilation relative to code requirements. However, there have been many anecdotal reports of poor CO{sub 2} sensor performance in actual commercial building applications. This study evaluated the accuracy of 44 CO{sub 2} sensors located in nine commercial buildings to determine if CO{sub 2} sensor performance, in practice, is generally acceptable or problematic. CO{sub 2} measurement errors varied widely and were sometimes hundreds of parts per million. Despite its small size, this study provides a strong indication that the accuracy of CO{sub 2} sensors used in commercial buildings is frequently less than is needed to measure peak indoor-outdoor CO{sub 2} concentration differences with less than a 20% error. Thus, we conclude that there is a need for more accurate CO{sub 2} sensors and/or better sensor maintenance or calibration procedures.

  8. Evolution of compact electrochemical in-situ pH-pCO2 sensor using ISFET-pH electrode

    Science.gov (United States)

    Shitashima, K.

    2011-12-01

    The measurement of pH in the marine system is important because this parameter related to the chemical equilibrium conditions of the seawater and the biological and chemical processes occurring in the sea. In particular, the pH of seawater is reflected in the exchange of CO2 between the atmosphere and the ocean, and oceanic carbon cycles. A change of pH and pCO2 in seawater should preferably be observed continually in a long term and a wide area to monitor air-sea CO2 exchange and oceanic carbon cycle concerning the global warming. Unfortunately, the onboard measurement of pH and pCO2 in seawater is not convenient for the long term and continuous observations. In-situ measurement with a sensor is the most suitable for such observations, but a marketed in-situ pH sensor using a glass electrode cannot detect a detailed pH change because precision is extremely low and response time is too long. In addition, in the pCO2 measurement, it is limited to only a measurement at the marine surface under the present conditions. A non-glass type in-situ pH sensor which uses an ion-sensitive field-effect transistor (ISFET) as the pH electrode, and a chloride ion selective electrode (Cl-ISE) as the reference electrode was developed by Shitashima and Kyo in 1998. For the pCO2 sensor, the pH sensor was sealed with a gas permeable membrane filled with the inner solution (Shitashima et al. 2002). Several sea tests of the sensor were carried out at various locations in the ocean, and the results of the tests showed high accuracy, quick response, and long-term stability. In the field, the in-situ response time of the devised pH sensor is as quick as 1 second or less, and the estimated measurement accuracy is ±0.005 pH units and a depth rating of 6000 m. The in-situ (3000 m depth, 1.8C) response time of the pCO2 sensor was less than 60 seconds. In order to adapt the in-situ pH-pCO2 sensor to wide area mapping and/or long term monitoring of pH and pCO2 in the ocean, the sensor was

  9. Physical Activation of Oil Palm Empty Fruit Bunch via CO2 Activation Gas for CO2 Adsorption

    Science.gov (United States)

    Joseph, C. G.; Quek, K. S.; Daud, W. M. A. W.; Moh, P. Y.

    2017-06-01

    In this study, different parameters for the preparation of activated carbon were investigated for their yield and CO2 capture capabilities. The activated carbon was prepared from Oil Palm Empty Fruit Bunch (OPEFB) via a 2-step physical activation process. The OPEFB was pyrolyzed under inert conditions at 500 °C and activated via CO2. A 2-factorial design was employed and the effects of activation temperature, activation dwell time and gas flow rate on yield and CO2 capture capabilities were compared and studied. The yield obtained ranged from between 20 - 26, whereby the temperature was determined to be the most significant factor in influencing CO2 uptake. The CO2 capture capacity was determined using Temperature Programmed Desorption (TPD) technique. The CO2 uptake of EFB activated carbon achieved was between 1.85 - 2.09 mmol/g. TPD analysis has shown that the surface of AC were of basic nature. AC was found to be able to withhold the CO2 up to 663°C before maximum desorption occurs. The surface area and pore size of OPEFB obtained from BET analysis is 2.17 m2 g-1 and 0.01 cm3 g-1. After activation, both surface area and pore size increased with a maximum observed surface area and pore size of 548.07 m2 g-1 and 0.26 cm3 g-1. Surface morphology, functional groups, pore size and surface area were analyzed using SEM, FT-IR, TPD and BET.

  10. Near-infrared absorption fiber-optic sensors for ultra-sensitive CO2 detection

    Science.gov (United States)

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

    2015-05-01

    We present a fiber-optic sensor working at near-infrared (NIR) wavelength (~1.57μm) for CO2 detection. In order to increase the NIR absorption, we utilize functional sensor materials metalorganic framework (MOF) on the surface of the core of a multimode-fiber with the cladding layer etched away. The selected functional materials demonstrated excellent adsorption capacity of CO2 and significantly increased the detection sensitivity down to 500 ppm with only 8-centimeter absorption length.

  11. Suitability Evaluation of Multipoint Simultaneous CO2 Sampling Wireless Sensors for Livestock Buildings

    Directory of Open Access Journals (Sweden)

    Salvador Calvet

    2014-06-01

    Full Text Available The environment in livestock buildings must be controlled to ensure the health and welfare of both workers and animals, as well as to restrict the emission of pollutants to the atmosphere. Among the pollutants generated inside these premises, carbon dioxide (CO2 is of great interest in terms of animal welfare and ventilation control. The use of inexpensive sensors means that complete systems can be designed with a number of sensors located around the building. This paper describes a study of the suitability of multipoint simultaneous CO2 sensors operating in a wireless sensor network, which was found to operate satisfactorily under laboratory conditions and was found to be the best alternative for these applications. The sensors showed a highly linear response to CO2 concentrations, ranging from 500 to 5000 ppm. However, individual sensor response was found to differ, which made it necessary to calibrate each one separately. Sensor precision ranged between 80 and 110 ppm CO2, and sensor response to register a 95% change in concentration was estimated at around 5 min. These features mean this type of sensor network can be used to monitor animal welfare and also for environmental control in poorly ventilated livestock premises. According to the tests conducted in this study, a temporal drift may occur and therefore a regular calibration of sensors would be needed.

  12. CO2 Plasticization of Polyethersulfone/Polyimide Gas-Separation Membranes

    NARCIS (Netherlands)

    Kapantaidakis, G.; Koops, G.H.; Wessling, Matthias; Kaldis, S.P.; Sakellaropoulos, G.P.

    2003-01-01

    This work reports the CO2 plasticization of gas-separation hollow-fiber membranes based on polyimide and polyethersulfone blends. The feed pressure effect on the permeance of pure gases (CO2, N2) and the separation performance of a gaseous mixture (CO2/N2, 55/45%) is examined. Contrary to dense

  13. 基于红外传感器的CO2测量装置%CO2 measuring device based on infrared sensor

    Institute of Scientific and Technical Information of China (English)

    王莉; 陈小平

    2011-01-01

    根据Beer-Lambert定理和红外吸收原理,研究了红外传感器的工作原理,设计了一种CO2气体体积分数测量装置.简要说明了整个装置的架构,硬件设计和软件程序设计.并利用Matlab对体积分数在0%~20%之间的测量数据进行了拟合,相关系数在0.98以上.该测量装置可对CO2体积分数进行实时准确的测量,稳定性好、体积小.%The working principle of infrared sensors is studied and a gas volume fraction measuring device for CO, is designed,according to Beer-Lambert law and infrared absorption principle. A brief description of the whole architecture of the device is illustrated, including the design of hardware and software. Matlab is used to fit measurement datas of volume fraction ranges from 0 % ~20 % ,the correlation coefficient achieves above 0.98. This device can measure the volume fraction of CO2 accurately in real time, and has good stability and small in size.

  14. CO2 , NOx and SOx removal from flue gas via microalgae cultivation: a critical review.

    Science.gov (United States)

    Yen, Hong-Wei; Ho, Shih-Hsin; Chen, Chun-Yen; Chang, Jo-Shu

    2015-06-01

    Flue gas refers to the gas emitting from the combustion processes, and it contains CO2 , NOx , SOx and other potentially hazardous compounds. Due to the increasing concerns of CO2 emissions and environmental pollution, the cleaning process of flue gas has attracted much attention. Using microalgae to clean up flue gas via photosynthesis is considered a promising CO2 mitigation process for flue gas. However, the impurities in the flue gas may inhibit microalgal growth, leading to a lower microalgae-based CO2 fixation rate. The inhibition effects of SOx that contribute to the low pH could be alleviated by maintaining a stable pH level, while NOx can be utilized as a nitrogen source to promote microalgae growth when it dissolves and is oxidized in the culture medium. The yielded microalgal biomass from fixing flue gas CO2 and utilizing NOx and SOx as nutrients would become suitable feedstock to produce biofuels and bio-based chemicals. In addition to the removal of SOx , NOx and CO2 , using microalgae to remove heavy metals from flue gas is also quite attractive. In conclusion, the use of microalgae for simultaneous removal of CO2 , SOx and NOx from flue gas is an environmentally benign process and represents an ideal platform for CO2 reutilization. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Microfabricated Formaldehyde Gas Sensors

    Directory of Open Access Journals (Sweden)

    Karen C. Cheung

    2009-11-01

    Full Text Available Formaldehyde is a volatile organic compound that is widely used in textiles, paper, wood composites, and household materials. Formaldehyde will continuously outgas from manufactured wood products such as furniture, with adverse health effects resulting from prolonged low-level exposure. New, microfabricated sensors for formaldehyde have been developed to meet the need for portable, low-power gas detection. This paper reviews recent work including silicon microhotplates for metal oxide-based detection, enzyme-based electrochemical sensors, and nanowire-based sensors. This paper also investigates the promise of polymer-based sensors for low-temperature, low-power operation.

  16. Stability aspects of a fiber optic sensor for CO2 phase monitoring

    Science.gov (United States)

    Prada, Dario; Martelli, Cicero; Gouvêa, Paula M. P.; Kato, Carla C.; Braga, Arthur M. B.; Gomes, Marcos S. P.

    2015-09-01

    In this paper we discuss the stability and effectiveness of an optical fiber sensor for CO2 phase monitoring that could be used inside pipelines, rock caverns and steel tanks for Carbon Capture and Storage (CCS) systems; in Enhanced Oil Recovery (EOR) processes; and in mapping of natural reservoirs. The sensor is an optical fiber refractometer and is shown to be capable of identifying phase changes and when two-phase systems co-exist, even near the phase transition line. When properly calibrated, the sensor can be used to obtain the refractive index and density (calculated with the Lorentz-Lorentz formula) of CO2.

  17. Capture and separation of CO2 from flue gas by coupling free and immobilized amines

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel system has been proposed for the capture and separation of CO2 from flue gas. In this method, a resin isemployed to regenerate the amine capturing CO2 from flue gas atroom temperatures. The feasibility for the resin to regenerateamines such as MEA, MAE, TEA, and ammonia has been demonstrated. It was also discovered that the resin could be regenerated by hotwater.

  18. Predicting gas decomposition in an industrialized pulsed CO2 laser

    CSIR Research Space (South Africa)

    Forbes, A

    2005-03-01

    Full Text Available A model is developed for the breakdown and regeneration of component gases in an industrialised TEA CO2 laser, both with and without internal catalysts, and is found to be in excellent agreement with experimental data. The laser was found...

  19. Modeling CO2 air dispersion from gas driven lake eruptions (Invited)

    OpenAIRE

    Chiodini, G.(INFN Sezione di Lecce, Lecce, Italy); COSTA, A.; Rouwet, D; F. Tassi

    2010-01-01

    The most tragic event of gas driven lake eruption occurred at Lake Nyos (Cameroon) on 21 August 1986, when a dense cloud of CO2 suffocated more than 1700 people and an uncounted number of animals in just one night. The event stimulated a series of researches aimed to understand gas origins, gas release mechanisms and strategies for gas hazard mitigation. Very few studies have been carried out for describing the transport of dense CO2 clouds in the atmosphere. Although from a...

  20. TREATMENT OF NATURAL GAS BY ADSORPTION OF CO2

    OpenAIRE

    Kristýna Hádková; Viktor Tekáč; Karel Ciahotný; Zdeněk Beňo; Veronika Vrbová

    2015-01-01

    Apart from burning, one of the possible uses of natural gas is as a fuel for motor vehicles. There are two types of fuel from natural gas — CNG (Compressed Natural Gas) or LNG (Liquefied Natural Gas). Liquefaction of natural gas is carried out for transport by tankers, which are an alternative to long-distance gas pipelines, as well as for transport over short distance, using LNG as a fuel for motor vehicles. A gas adjustment is necessary to get LNG. As an important part of the necessary adju...

  1. Technical note: Assessing gas equilibration systems for continuous pCO2 measurements in inland waters

    Science.gov (United States)

    Yoon, Tae Kyung; Jin, Hyojin; Oh, Neung-Hwan; Park, Ji-Hyung

    2016-07-01

    High-frequency continuous measurements of the partial pressure of CO2 (pCO2) are crucial for constraining the spatiotemporal dynamics of CO2 emissions from inland water systems. However, direct measurements of pCO2 are scarce, and no systematic comparisons have been conducted on the suitability of the widely used measurement systems for continuous underway or long-term deployment in various field conditions. We compared spray- and marble-type equilibrators and a membrane-enclosed CO2 sensor to assess their suitability for continuous long-term or underway pCO2 measurements in an urbanized river system in Korea. Both equilibrators had a shorter response time compared with the membrane-enclosed sensor, and could capture large spatial variations of pCO2 during a transect study along a highly urbanized river reach. The membrane-enclosed sensor based on passive equilibration provided comparable underway measurements along the river sections where pCO2 varied within the sensor detection range. When deployed in a eutrophic river site, the membrane-enclosed sensor was able to detect large diel variations in pCO2. However, biofouling on the membrane could reduce the accuracy of the measurement during long deployments exceeding several days. The overall results suggest that the fast response of the equilibrator systems facilitates capturing large spatial variations in pCO2 during short underway measurements. However, the attendant technical challenges of these systems, such as clogging and desiccant maintenance, have to be addressed carefully to enable their long-term deployment. The membrane-enclosed sensor would be suitable as an alternative tool for long-term continuous measurements if membrane biofouling could be overcome by appropriate antifouling measures such as copper mesh coverings.

  2. Measurement of CO(2) Dissolved in Aqueous Solutions Using a Modified Infrared Gas Analyzer System.

    Science.gov (United States)

    Schumacher, T E; Smucker, A J

    1983-05-01

    Total dissolved inorganic carbon (SigmaCO(2)) and aqueous carbon dioxide (H(2)CO(3) (*)) in nutrient solutions may be measured by the injection of small gas or liquid samples (1 microliter to 8 milliliters) into a gas stripping column connected in-line with an infrared gas analyzer. The measurement of SigmaCO(2) in solution requires sample acidification, while H(2)CO(3) (*) and gaseous CO(2) are measured without the addition of lactic acid. The standard curve for SigmaCO(2) was linear up to 300 nanomoles CO(2). Maximum sensitivity was approximately 300 picomoles. Measurements of H(2)CO(3) (*) were independent of pH. Consequently, SigmaCO(2) and H(2)CO(3) (*) could be used to calculate the pH, HCO(3) (-), and CO(3) (2-) values of nutrient solutions. Injection and complete analyses required from 0.8 to 2 minutes.

  3. About the development of single microdischarges in dielectric barrier discharges in CO2 and CO2/N2 gas mixtures. DBD-MDs in CO2 and CO2/N2

    Science.gov (United States)

    Brandenburg, Ronny; Sarani, Abdollah

    2017-08-01

    The conversion of carbon dioxide as one of the main greenhouse gases into carbon monoxide as a chemical feedstock is considered as so-called carbon capture usage technology. Recently it was shown, that the dissociation of carbon dioxide to carbon monoxide in Dielectric Barrier Discharges can be enhanced by the addition of nitrogen gas. Here, the development of microdischarges in CO2 and CO2/N2 gas mixtures is studied. Therefore, a single filament DBD arrangement operated under sinusoidal high-voltage is investigated by means of spectroscopic and electrical diagnostics with high spatial and temporal resolution and sensitivity. The filament development is similar as in air or other nitrogen-oxygen gas mixtures, but the gas composition influences the duration and other parameters. The higher the CO2 content the weaker the filaments and the faster the quenching of excited molecular states. The optimum power dissipation into single discharge is obtained for a CO2 content between 20 and 30 vol.%.

  4. High-precision gas gain and energy transfer measurements in Ar–CO2 mixtures

    CERN Document Server

    Şahin, Özkan; Veenhof, Rob

    2014-01-01

    Ar–CO2 is a Penning mixture since a fraction of the energy stored in Ar 3p53d3p53d and higher excited states can be transferred to ionize CO2 molecules. In the present work, concentration and pressure dependence of Penning transfer rate and photon feedback parameter in Ar–CO2 mixtures have been investigated with recent systematic high-precision gas gain measurements which cover the range 1–50% CO2 at 400, 800, 1200, 1800 hPa and gas gain from 1 to 5×105.

  5. Formation of Carbamate Anions by the Gas-phase Reaction of Anilide Ions with CO2.

    Science.gov (United States)

    Liu, Chongming; Nishshanka, Upul; Attygalle, Athula B

    2016-05-01

    The anilide anion (m/z 92) generated directly from aniline, or indirectly as a fragmentation product of deprotonated acetanilide, captures CO2 readily to form the carbamate anion (m/z 136) in the collision cell, when CO2 is used as the collision gas in a tandem-quadrupole mass spectrometer. The gas-phase affinity of the anilide ion to CO2 is significantly higher than that of the phenoxide anion (m/z 93), which adds to CO2 only very sluggishly. Our results suggest that the efficacy of CO2 capture depends on the natural charge density on the nitrogen atom, and relative nucleophilicity of the anilide anion. Generally, conjugate bases generated from aniline derivatives with proton affinities (PA) less than 350 kcal/mol do not tend to add CO2 to form gaseous carbamate ions. For example, the anion generated from p-methoxyaniline (PA = 367 kcal/mol) reacts significantly faster than that obtained from p-nitroaniline (PA = 343 kcal/mol). Although deprotonated p-aminobenzoic acid adds very poorly because the negative charge is now located primarily on the carboxylate group, it reacts more efficiently with CO2 if the carboxyl group is esterified. Moreover, mixture of CO2 and He as the collision gas was found to afford more efficient adduct formation than CO2 alone, or as mixtures made with nitrogen or argon, because helium acts as an effective "cooling" gas and reduces the internal energy of reactant ions.

  6. Formation of Carbamate Anions by the Gas-phase Reaction of Anilide Ions with CO2

    Science.gov (United States)

    Liu, Chongming; Nishshanka, Upul; Attygalle, Athula B.

    2016-05-01

    The anilide anion ( m/z 92) generated directly from aniline, or indirectly as a fragmentation product of deprotonated acetanilide, captures CO2 readily to form the carbamate anion ( m/z 136) in the collision cell, when CO2 is used as the collision gas in a tandem-quadrupole mass spectrometer. The gas-phase affinity of the anilide ion to CO2 is significantly higher than that of the phenoxide anion ( m/z 93), which adds to CO2 only very sluggishly. Our results suggest that the efficacy of CO2 capture depends on the natural charge density on the nitrogen atom, and relative nucleophilicity of the anilide anion. Generally, conjugate bases generated from aniline derivatives with proton affinities (PA) less than 350 kcal/mol do not tend to add CO2 to form gaseous carbamate ions. For example, the anion generated from p-methoxyaniline (PA = 367 kcal/mol) reacts significantly faster than that obtained from p-nitroaniline (PA = 343 kcal/mol). Although deprotonated p-aminobenzoic acid adds very poorly because the negative charge is now located primarily on the carboxylate group, it reacts more efficiently with CO2 if the carboxyl group is esterified. Moreover, mixture of CO2 and He as the collision gas was found to afford more efficient adduct formation than CO2 alone, or as mixtures made with nitrogen or argon, because helium acts as an effective "cooling" gas and reduces the internal energy of reactant ions.

  7. MEMBRANE PROCESS TO SEQUESTER CO2 FROM POWER PLANT FLUE GAS

    Energy Technology Data Exchange (ETDEWEB)

    Tim Merkel; Karl Amo; Richard Baker; Ramin Daniels; Bilgen Friat; Zhenjie He; Haiqing Lin; Adrian Serbanescu

    2009-03-31

    The objective of this project was to assess the feasibility of using a membrane process to capture CO2 from coal-fired power plant flue gas. During this program, MTR developed a novel membrane (Polaris™) with a CO2 permeance tenfold higher than commercial CO2-selective membranes used in natural gas treatment. The Polaris™ membrane, combined with a process design that uses a portion of combustion air as a sweep stream to generate driving force for CO2 permeation, meets DOE post-combustion CO2 capture targets. Initial studies indicate a CO2 separation and liquefaction cost of $20 - $30/ton CO2 using about 15% of the plant energy at 90% CO2 capture from a coal-fired power plant. Production of the Polaris™ CO2 capture membrane was scaled up with MTR’s commercial casting and coating equipment. Parametric tests of cross-flow and countercurrent/sweep modules prepared from this membrane confirm their near-ideal performance under expected flue gas operating conditions. Commercial-scale, 8-inch diameter modules also show stable performance in field tests treating raw natural gas. These findings suggest that membranes are a viable option for flue gas CO2 capture. The next step will be to conduct a field demonstration treating a realworld power plant flue gas stream. The first such MTR field test will capture 1 ton CO2/day at Arizona Public Service’s Cholla coal-fired power plant, as part of a new DOE NETL funded program.

  8. MEMBRANE PROCESS TO SEQUESTER CO2 FROM POWER PLANT FLUE GAS

    Energy Technology Data Exchange (ETDEWEB)

    Tim Merkel; Karl Amo; Richard Baker; Ramin Daniels; Bilgen Friat; Zhenjie He; Haiqing Lin; Adrian Serbanescu

    2009-03-31

    The objective of this project was to assess the feasibility of using a membrane process to capture CO2 from coal-fired power plant flue gas. During this program, MTR developed a novel membrane (Polaris™) with a CO2 permeance tenfold higher than commercial CO2-selective membranes used in natural gas treatment. The Polaris™ membrane, combined with a process design that uses a portion of combustion air as a sweep stream to generate driving force for CO2 permeation, meets DOE post-combustion CO2 capture targets. Initial studies indicate a CO2 separation and liquefaction cost of $20 - $30/ton CO2 using about 15% of the plant energy at 90% CO2 capture from a coal-fired power plant. Production of the Polaris™ CO2 capture membrane was scaled up with MTR’s commercial casting and coating equipment. Parametric tests of cross-flow and countercurrent/sweep modules prepared from this membrane confirm their near-ideal performance under expected flue gas operating conditions. Commercial-scale, 8-inch diameter modules also show stable performance in field tests treating raw natural gas. These findings suggest that membranes are a viable option for flue gas CO2 capture. The next step will be to conduct a field demonstration treating a realworld power plant flue gas stream. The first such MTR field test will capture 1 ton CO2/day at Arizona Public Service’s Cholla coal-fired power plant, as part of a new DOE NETL funded program.

  9. CAPTURING EXHAUST CO2 GAS USING MOLTEN CARBONATE FUEL CELLS

    Directory of Open Access Journals (Sweden)

    Prateek Dhawan

    2016-03-01

    Full Text Available Carbon dioxide is considered as one of the major contenders when the question of greenhouse effect arises. So for any industry or power plant it is of utmost importance to follow certain increasingly stringent environment protection rules and laws. So it is significant to keep eye on any possible methods to reduce carbon dioxide emissions in an efficient way. This paper reviews the available literature so as to try to provide an insight of the possibility of using Molten Carbonate Fuel Cells (MCFCs as the carbon capturing and segregating devices and the various factors that affect the performance of MCFCs during the process of CO2 capture.

  10. Amino acid salt solutions as solvents in CO2 capture from flue gas

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai; Thomsen, Kaj; Stenby, Erling Halfdan

    New solvents based on the salts of amino acids have emerged as an alternative to the alkanolamine solutions, for the chemical absorption of CO2 from flue gas. But only few studies on amino acids as CO2 capturing agents have been performed so far. One of the interesting features of amino acid salt...... solutions is their ability to form solid precipitates upon the absorption of CO2. The occurrence of crystallization offers the possibility of increasing the CO2 loading capacity of the solvent. However, precipitation can also have negative effect on the CO2 capture process. The chemical nature of the solid...... of glycine, taurine, and lysine, while in the case of proline, and glutamic acid, the precipitate was found to be bicarbonate. These results give an important contribution to further understanding the potential of amino acid salt solutions in CO2 capture from flue gas....

  11. The injection of liquid cool CO2 in a warm depleted gas reservoir

    NARCIS (Netherlands)

    Hofstee, C.; Maas, J.H.; Loeve, D.

    2013-01-01

    The P18-4 compartment (operated by TAQA Energy B.V.) would be injected by CO2 at a minimum temperature of 12 degrees C. At these temperatures, the CO2 phase will either be a gas or a liquid. As the initial temperature of the reservoir is 120 oC, the CO2 will eventually be the gaseous or (at higher

  12. Highly integrated CO2 capture and conversion: Direct synthesis of cyclic carbonates from industrial flue gas

    KAUST Repository

    Barthel, Alexander

    2016-02-08

    Robust and selective catalytic systems based on early transition metal halides (Y, Sc, Zr) and organic nucleophiles were found able to quantitatively capture CO2 from diluted streams via formation of hemicarbonate species and to convert it to cyclic organic carbonates under ambient conditions. This observation was exploited in the direct and selective chemical fixation of flue gas CO2 collected from an industrial exhaust, affording high degrees of CO2 capture and conversion.

  13. CO2 Capture from Flue Gas using Amino Acid Salt Solutions

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai; Stenby, Erling Halfdan; Thomsen, Kaj

    2009-01-01

    difficult. Amino acid salt solutions have emerged as an alternative to the alkanolamine solutions. A number of advantages make amino acid salt solutions attractive solvents for CO2 capture from flue gas. In the present study CO2 absorption in aqueous solutions of 0.5 M potassium glycinate and 0.5 M...

  14. Geochemical evaluation of CO2 injection and containment in a depleted gas field

    NARCIS (Netherlands)

    Tambach, T.J.; Koenen, M.; Wasch, L.J.; Bergen, F. van

    2015-01-01

    The short- and long-term geochemical impact of CO2 injection into a depleted gas reservoir (DGR) is investigated using reservoir/geochemical modeling with TOUGH2/TOUGHREACT and 1D kinetic diffusion modeling with PHREEQC (caprock/well-cement). Simulations of CO2 injection into the reservoir predict d

  15. A Highly Stable Microporous Covalent Imine Network Adsorbent for Natural Gas Upgrading and Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan Kumar

    2016-06-06

    The feasible capture and separation of CO2 and N2 from CH4 is an important task for natural gas upgrading and the control of greenhouse gas emissions. Here, we studied the microporous covalent imine networks (CIN) material prepared through Schiff base condensation and exhibited superior chemical robustness under both acidic and basic conditions and high thermal stability. The material possesses a relatively uniform nanoparticle size of approximately 70 to 100 nm. This network featured permanent porosity with a high surface area (722 m2g-1) and micropores. A single-component gas adsorption study showed enhanced CO2 and CH4 uptakes of 3.32 mmol/g and 1.14 mmol/g, respectively, at 273 K and 1 bar, coupled with high separation selectivities for CO2/CH4, CH4/N2, and CO2/N2 of 23, 11.8 and 211, respectively. The enriched Lewis basicity in the porous skeletons favours the interaction of quadrupolar CO2 and polarizable CH4, resulting in enhanced CH4 and CO2 uptake and high CH4/N2, CO2/CH4 and CO2/N2 selectivities. Breakthrough experiments showed high CO2/CH4, CH4/N2 and CO2/N2 selectivities of 7.29, 40 and 125, respectively, at 298 K and 1 bar. High heats of adsorption for CH4 and CO2 (QstCH4; 32.61 kJ mol-1 and QstCO2; 42.42 kJ mol-1) provide the ultimate validation for the high selectivity. To the best of our knowledge, such a versatile adsorbent material that displays both enhanced uptake and selectivity for a variety of binary gas mixtures, including CO2/ CH4, CO2/N2 and CH4/N2, has not been extensively explored.

  16. Effect of temperature fluctuation on hydrate-based CO2 separation from fuel gas

    Institute of Scientific and Technical Information of China (English)

    Xiaosen Li; Chungang Xu; Zhaoyang Chen; Huijie Wu; Jing Cai

    2011-01-01

    A new method of temperature fluctuation is proposed to promote the process of hydrate-based CO2 separation from fuel gas in this work according to the dual nature of CO2 solubility in hydrate forming and non-hydrate forming regions [1].The temperature fluctuation operated in the process of hydrate formation improves the formation of gas hydrate observably.The amount of the gas consumed with temperature fluctuation is approximately 35% more than that without temperature fluctuation.It is found that only the temperature fluctuation operated in the period of forming hydrate leads to a good effect on CO2 separation.Meanwhile,with the proceeding of hydrate formation,the effect of temperature fluctuation on the gas hydrate gradually reduces,and little effect is left in the completion term.The CO2 separation efficiencies in the separation processes with the effective temperature fluctuations are improved remarkably.

  17. Analysis of CO2 Separation from Flue Gas, Pipeline Transportation, and Sequestration in Coal

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Robertson

    2007-09-01

    This report was written to satisfy a milestone of the Enhanced Coal Bed Methane Recovery and CO2 Sequestration task of the Big Sky Carbon Sequestration project. The report begins to assess the costs associated with separating the CO2 from flue gas and then injecting it into an unminable coal seam. The technical challenges and costs associated with CO2 separation from flue gas and transportation of the separated CO2 from the point source to an appropriate sequestration target was analyzed. The report includes the selection of a specific coal-fired power plant for the application of CO2 separation technology. An appropriate CO2 separation technology was identified from existing commercial technologies. The report also includes a process design for the chosen technology tailored to the selected power plant that used to obtain accurate costs of separating the CO2 from the flue gas. In addition, an analysis of the costs for compression and transportation of the CO2 from the point-source to an appropriate coal bed sequestration site was included in the report.

  18. Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

    Directory of Open Access Journals (Sweden)

    Sarkar Jahar

    2015-01-01

    Full Text Available The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

  19. Growth response of Spirulina platensis PCC9108 to elevated CO2 levels and flue gas

    Directory of Open Access Journals (Sweden)

    Seyedmahdi Hoseini

    2014-01-01

    Full Text Available Introduction: Because their ability to capture CO2, photosynthetical microorganisms have some advantages to CO2 mitigation from high CO2 streams such as flue gases and they can use CO2 as carbon source. Recently, experts have made efforts to exploit microorganisms intended for recovering CO2 from power plants. Materials and methods: To achieve this purpose, we studied the growth response of the cyanobacterium Spirulina platensis PCC9108 under different concentrations of carbon dioxide (ranging from 0.036% to 10% and flue gas in a bench-scale system. Preparation of different concentrations of CO2 and injection into Erlenmeyer flasks was performed by a system including air compressor, CO2 capsule, pressure gauge and flow meter. Results: The main goal of studying this paper is a survey of organism's potential to grow by generated CO2 from flue gas of power plant. It already had the potential and highest biomass production recorded at 8% CO2 (v/v. Also we proved that S.platensis PCC9108 can be grown under flue gas, although biomass production decreased fairly. Total lipid content of algae interestingly enhanced with elevated CO2 levels from ambient air to 4% and 6% which ranged from 14.5 to 15.8 and 16 dry weight (wt. % respectively. In contrast, total protein content illustrated no difference between all treatment and its value was about 46 wt.%. Discussion and conclusion: The results of present study suggested that understudied S.platensis PCC9108 is appropriate for mitigating CO2 because of its carbon fixation ability. Also due to its high protein content, this cyanobacterium is a good candidate to produce SCP (single cell protein.

  20. Simulasi Pengaruh Kandungan CO2 dalam Gas Umpan terhadap Reforming dan Shift Converter Sistem Pabrik Amoniak

    Directory of Open Access Journals (Sweden)

    Jefry Yusuf

    2015-12-01

    Full Text Available Perubahan produksi dan pangsa pasar gas alam domestik maupun global mempengaruhi suplai terhadap pabrik pupuk-amoniak baik dari sisi jumlah, komposisi maupun harga. Kondisi ini memungkinkan pabrik amoniak menerima jenis gas alam berat kaya dengan CO2 (raw gas maupun gas alam  ringan minim CO2 (treated gas. Pada penelitian ini telah dilakukan analisa pengaruh perubahan  komposisi gas alam terutama kandungan CO2 dengan variasi 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 dan 50% vol terhadap operasional reforming dan shift converter sistem pabrik amoniak-2 PT. PI Mexisting dengan metodelogi simulasi mengggunakan Aspen HYSYS V8.0. Untuk memproduksi amoniak dengan jumlah yang sama, hasil studi menunjukkan penambahan CO2 dalam gas umpan akan meningkatkan pressure drop sistem, laju pembentukan komponen hidrogen turun sementara konsumsi energi bertambah di reforming, beban katalis shift converter dan beban feed gas compressor meningkat. Kandungan CO2 sebesar 7% vol masih mungkin diaplikasikan, mengingat ada batasan beban peralatan.

  1. Application of Factorial Design for Gas Parameter Optimization in CO2 Laser Welding

    DEFF Research Database (Denmark)

    Gong, Hui; Dragsted, Birgitte; Olsen, Flemming Ove

    1997-01-01

    The effect of different gas process parameters involved in CO2 laser welding has been studied by applying two-set of three-level complete factorial designs. In this work 5 gas parameters, gas type, gas flow rate, gas blowing angle, gas nozzle diameter, gas blowing point-offset, are optimized...... to be a very useful tool for parameter optimi-zation in laser welding process. Keywords: CO2 laser welding, gas parameters, factorial design, Analysis of Variance........ The bead-on-plate welding specimens are evaluated by a number of quality char-acteristics, such as the penetration depth and the seam width. The significance of the gas pa-rameters and their interactions are based on the data found by the Analysis of Variance-ANOVA. This statistic methodology is proven...

  2. CO2-mitigation options for the offshore oil and gas sector

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Tock, Laurence; Breuhaus, Peter

    2016-01-01

    The offshore extraction of oil and gas is an energy-intensive process leading to the production of CO2and methane, discharged into the atmosphere, and of chemicals, rejected into the sea. The taxation of these emissions, in Norway, has encouraged the development of more energy-effcient and enviro......The offshore extraction of oil and gas is an energy-intensive process leading to the production of CO2and methane, discharged into the atmosphere, and of chemicals, rejected into the sea. The taxation of these emissions, in Norway, has encouraged the development of more energy......, using thermodynamic, economic and environmental indicators. The results indicate the benets of all these options, as the total CO2-emissions can be reduced by more than 15% in all cases, while the avoidance costs vary widely and are highly sensitive to the natural gas price and CO2-tax....

  3. Gas sensors based on nanostructured materials.

    Science.gov (United States)

    Jiménez-Cadena, Giselle; Riu, Jordi; Rius, F Xavier

    2007-11-01

    Gas detection is important for controlling industrial and vehicle emissions, household security and environmental monitoring. In recent decades many devices have been developed for detecting CO(2), CO, SO(2), O(2), O(3), H(2), Ar, N(2), NH(3), H(2)O and several organic vapours. However, the low selectivity or the high operation temperatures required when most gas sensors are used have prompted the study of new materials and the new properties that come about from using traditional materials in a nanostructured mode. In this paper, we have reviewed the main research studies that have been made of gas sensors that use nanomaterials. The main quality characteristics of these new sensing devices have enabled us to make a critical review of the possible advantages and drawbacks of these nanostructured material-based sensors.

  4. Biomimetic Membrane for CO2 Capture from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Michael C. Trachtenberg

    2007-05-31

    These Phase III experiments successfully addressed several issues needed to characterize a permeator system for application to a pulverized coal (PC) burning furnace/boiler assuming typical post-combustion cleanup devices in place. We completed key laboratory stage optimization and modeling efforts needed to move towards larger scale testing. The SOPO addressed six areas. Task 1--Post-Combustion Particle Cleanup--The first object was to determine if the Carbozyme permeator performance was likely to be reduced by particles (materials) in the flue gas stream that would either obstruct the mouth of the hollow fibers (HF) or stick to the HF bore wall surface. The second, based on the Acceptance Standards (see below), was to determine whether it would be preferable to clean the inlet gas stream (removing acid gases and particulates) or to develop methods to clean the Carbozyme permeator if performance declined due to HF block. We concluded that condensation of particle and particulate emissions, in the heat exchanger, could result in the formation of very sticky sulfate aerosols with a strong likelihood of obtruding the HF. These must be managed carefully and minimized to near-zero status before entering the permeator inlet stream. More extensive post-combustion cleanup is expected to be a necessary expense, independent of CO{sub 2} capture technology This finding is in agreement with views now emerging in the literature for a variety of CO{sub 2} capture methods. Task 2--Water Condensation--The key goal was to monitor and control temperature distributions within the permeator and between the permeator and its surroundings to determine whether water condensation in the pores or the HF bore would block flow, decreasing performance. A heat transfer fluid and delivery system were developed and employed. The result was near isothermal performance that avoided all instances of flow block. Direct thermocouple measurements provided the basis for developing a heat transfer

  5. Biomimetic Membrane for CO2 Capture from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Michael C. Trachtenberg

    2007-05-31

    These Phase III experiments successfully addressed several issues needed to characterize a permeator system for application to a pulverized coal (PC) burning furnace/boiler assuming typical post-combustion cleanup devices in place. We completed key laboratory stage optimization and modeling efforts needed to move towards larger scale testing. The SOPO addressed six areas. Task 1--Post-Combustion Particle Cleanup--The first object was to determine if the Carbozyme permeator performance was likely to be reduced by particles (materials) in the flue gas stream that would either obstruct the mouth of the hollow fibers (HF) or stick to the HF bore wall surface. The second, based on the Acceptance Standards (see below), was to determine whether it would be preferable to clean the inlet gas stream (removing acid gases and particulates) or to develop methods to clean the Carbozyme permeator if performance declined due to HF block. We concluded that condensation of particle and particulate emissions, in the heat exchanger, could result in the formation of very sticky sulfate aerosols with a strong likelihood of obtruding the HF. These must be managed carefully and minimized to near-zero status before entering the permeator inlet stream. More extensive post-combustion cleanup is expected to be a necessary expense, independent of CO{sub 2} capture technology This finding is in agreement with views now emerging in the literature for a variety of CO{sub 2} capture methods. Task 2--Water Condensation--The key goal was to monitor and control temperature distributions within the permeator and between the permeator and its surroundings to determine whether water condensation in the pores or the HF bore would block flow, decreasing performance. A heat transfer fluid and delivery system were developed and employed. The result was near isothermal performance that avoided all instances of flow block. Direct thermocouple measurements provided the basis for developing a heat transfer

  6. Joule-Thomson Cooling Due to CO2 Injection into Natural Gas Reservoirs

    OpenAIRE

    Oldenburg, Curtis M.

    2006-01-01

    Depleted natural gas reservoirs are a promising target for Carbon Sequestration with Enhanced Gas Recovery (CSEGR). The focus of this study is on evaluating the importance of Joule-Thomson cooling during CO2 injection into depleted natural gas reservoirs. Joule-Thomson cooling is the adiabatic cooling that accompanies the expansion of a real gas. If Joule-Thomson cooling were extreme, injectivity and formation permeability could be altered by the freezing of residual water, formation of ...

  7. Imagining CO2: development and assessment of interactive visualizations for high resolution greenhouse gas observations collected by BEACO2N

    Science.gov (United States)

    Raheja, G.; Shusterman, A.; Martin, S.; Shahar, E.; Laughner, J.; Turner, A. J.; Miller, M. K.; Cohen, R. C.

    2016-12-01

    The Berkeley Atmospheric CO2 Observation Network (BEACO2N) is a high-density network of 28 carbon dioxide sensors distributed around the San Francisco Bay Area that serve to enhance understanding of intra-city variations in CO2 concentrations that are not necessarily captured by sparser networks maintained by local and national air quality management agencies. We partner with designers at the San Francisco Exploratorium to create a suite of interactive exhibits and hands-on activities that creatively visualize data from BEACO2N for general audiences. Museum goers can manipulate a light-up "bar graph" of live CO2 concentrations by exhaling on an in-room sensor, query the current readings of rooftop sensors using a scale model of the Wired Pier observation system, scroll through the data from other BEACO2N sites projected on a 3-D "topographic table" of the Bay Area, and view interpolated CO2 fields driven by research-grade weather models on a nine-screen LCD display. We present lessons learned from these initial installations, from layperson audience feedback to details of the Stochastic Time-Inverted Lagrangian Transport (STILT) model coupled to Weather Research and Forecasting (WRF) weather fields used to generate intuitive concentration maps. We propose that compelling visual demonstrations of elevated CO2 concentrations due to routine small-scale high-emission anthropogenic activities (e.g. rush hour) and/or special events (such as fireworks or factory fires) generate deeper engagement in local environmental issues and interest in undertaking personal actions that can become part of the broader climate solution. While global means and other large-scale aggregate climate metrics can lead to feelings of disconnect and subsequent ambivalence, via such exhibitions, distributed network instruments like BEACO2N can provide the local sensitivity needed to "personalize" greenhouse gas concentrations to a given individual or community and incite the drive toward

  8. Atmospheric radon, CO2 and CH4 dynamics in an Australian coal seam gas field

    Science.gov (United States)

    Tait, D. R.; Santos, I. R.; Maher, D. T.

    2013-12-01

    Atmospheric radon (222Rn), carbon dioxide (CO2), and methane concentrations (CH4) as well as carbon stable isotope ratios (δ13C) were used to gain insight into atmospheric chemistry within an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). A˜3 fold increase in maximum 222Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average 222Rn concentrations and the number of gas wells within a 2 km to 4 km radius of the sampling sites (n = 5 stations; p gas field related to point sources (well heads, pipelines, etc.) and diffse soil sources due to changes in the soil structural and hydrological characteristics. A rapid qualitative assessment of CH4 and CO2 concentration, and carbon isotopes using a mobile cavity ring-down spectrometer system showed a widespread enrichment of both CH4 and CO2 within the production gas field. Concentrations of CH4 and CO2 were as high as 6.89 ppm and 541 ppm respectively compared average concentrations of 1.78 ppm (CH4) and 388 ppm (CO2) outside the gas field. The δ13C values showed distinct differences between areas inside and outside the production field with the δ13C value of the CH4 source within the field matching that of the methane in the CSG.

  9. Effects of CO 2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification

    KAUST Repository

    Omole, Imona C.

    2010-05-19

    A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO2 partial pressures. The cross-linked membrane material shows high intrinsic separation performance for CO2 and CH4 (selectivity ∼49, CO2 permeability ∼161 barrer, with a feed at 65 psia, 35 °C, and 10% CO2). Cross-linked asymmetric hollow-fiber membranes made from the material show good resistance to CO2-induced plasticization. Carbon dioxide partial pressures as high as ∼400 psia were employed, and the membrane was shown to be promisingly stable under these aggressive conditions. The performance of the membrane was also analyzed using the dual-mode sorption/transport model. © 2010 American Chemical Society.

  10. Lagrangian simulation of deposition of CO2 gas-solid sudden expansion flow

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Freezing and blockage resulting from the deposition of solid CO2 formed because of sudden expansion of the downstream pipe during the release of CO2 through safety valves,will endanger the protected equipment.To overcome this problem,the characteristics of the CO2 gas-solid sudden expansion flow are studied by using the disperse Lagrangian model.A comparison of the calculated deposition of the solid CO2 with the experimental results shows that they are in reasonable agreement.The simulation results show that the size of the solid CO2 formed should not be in the range of 0.04-0.07 mm (St number 3.2-9.8).This can be achieved by using an appropriate flow cross section of the safety valve.

  11. A Technical and Economical Evaluation of CO2 Capture from Fluidized Catalytic Cracking (FCC Flue Gas

    Directory of Open Access Journals (Sweden)

    Digne Romina

    2014-11-01

    Full Text Available Environmental issues, related to greenhouse gas and among them CO2, are becoming short term challenges. Pressure on industries and therefore on refining to limit and manage CO2 emissions will be reinforced in next few years. Refining industry is responsible for about 2.7% of global CO2 emissions. Fluidized Catalytic Cracking unit (FCC, one of the main process in refining, represents by itself 20% of the refinery CO2 emissions. As FCC unit is present in half of the refining schemes, it is challenging to find technologies to manage its emissions. Based on an industrial case, the aims of the presented work are to determine if amine technology HiCapt+, developed for power plant, might be a relevant solution to manage FCC CO2 emissions and to evaluate the additional cost to be supported by refiners.

  12. Early detection of cardiac ischemia using a conductometric pCO(2) sensor: real-time drift correction and parameterization.

    Science.gov (United States)

    Tronstad, Christian; Pischke, Soeren E; Holhjem, Lars; Tønnessen, Tor Inge; Martinsen, Orjan G; Grimnes, Sverre

    2010-09-01

    For detection of cardiac ischemia based on regional pCO(2) measurement, sensor drift becomes a problem when monitoring over several hours. A real-time drift correction algorithm was developed based on utilization of the time-derivative to distinguish between physiological responses and the drift, customized by measurements from a myocardial infarction porcine model (6 pigs, 23 sensors). IscAlert conductometric pCO(2) sensors were placed in the myocardial regions supplied by the left anterior descending coronary artery (LAD) and the left circumflex artery (LCX) while the LAD artery was fully occluded for 1, 3, 5 and 15 min leading to ischemia in the LAD-dependent region. The measured pCO(2), the drift-corrected pCO(2) (DeltapCO(2)) and its time-derivative (TDpCO(2)) were compared with respect to detection ability. Baseline stability in the DeltapCO(2) led to earlier, more accurate detection. The TDpCO(2) featured the earliest sensitivity, but with a lower specificity. Combining DeltapCO(2) and TDpCO(2) enables increased accuracy. Suggestions are given for the utilization of the parameters for an automated early warning and alarming system. In conclusion, early detection of cardiac ischemia is feasible using the conductometric pCO(2) sensor together with parameterization methods.

  13. New absorption liquids for the removal of CO2 from dilute gas streams using membrane contactors

    NARCIS (Netherlands)

    Kumar, P.S.; Hogendoorn, J.A.; Feron, P.H.M.; Versteeg, G.F.

    2002-01-01

    A new absorption liquid based on amino acid salts has been studied for CO2 removal in membrane gas-liquid contractors. Unlike conventional gas treating solvents like aqueous alkanolamines solutions, the new absorption liquid does not wet polyolefin microporous membranes. The wetting characteristics

  14. Effect of gas field production and CO2 injection on brine flow and salt precipitation

    NARCIS (Netherlands)

    Loeve, D.; Tambach, T.J.; Hofstee, C.; Plug, W.J.; Maas, J.

    2012-01-01

    This paper reports modeling of gas field produc-tion and CO2 injection from a theoretical reser-voir based on characteristics of the P18 gas field in the Dutch offshore, which consists of four geological deposits with different petrophysical properties. We especially focus on the brine flow during

  15. Effect of CO2 injection on brine flow and salt precipitation after gas field production

    NARCIS (Netherlands)

    Tambach, T.J.; Loeve, D.; Hofstee, C.; Plug, W.J.; Maas, J.G.

    2014-01-01

    This paper reports modeling of gas field production and CO2 injection in a theoretical reservoir based on characteristics of the P18 gas field in the Dutch offshore, which consists of four geological deposits with different petrophysical properties. We especially focus on the brine flow during and

  16. Water-gas shift (WGS) Operation of Pre-combustion CO2 Capture Pilot Plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Van Dijk, H.A.J.; Damen, K.; Makkee, M.; Trapp, C.

    2014-01-01

    In the Nuon/Vattenfall CO2 Catch-up project, a pre-combustion CO2 capture pilot plant was built and operated at the Buggenum IGCC power plant, the Netherlands. The pilot consist of sweet water-gas shift, physical CO2 absorption and CO2 compression. The technology performance was verified and validat

  17. Water-gas shift (WGS) Operation of Pre-combustion CO2 Capture Pilot Plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Van Dijk, H.A.J.; Damen, K.; Makkee, M.; Trapp, C.

    2014-01-01

    In the Nuon/Vattenfall CO2 Catch-up project, a pre-combustion CO2 capture pilot plant was built and operated at the Buggenum IGCC power plant, the Netherlands. The pilot consist of sweet water-gas shift, physical CO2 absorption and CO2 compression. The technology performance was verified and

  18. Water-gas shift (WGS) Operation of Pre-combustion CO2 Capture Pilot Plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Van Dijk, H.A.J.; Damen, K.; Makkee, M.; Trapp, C.

    2014-01-01

    In the Nuon/Vattenfall CO2 Catch-up project, a pre-combustion CO2 capture pilot plant was built and operated at the Buggenum IGCC power plant, the Netherlands. The pilot consist of sweet water-gas shift, physical CO2 absorption and CO2 compression. The technology performance was verified and validat

  19. 高含CO2气井产能计算新方法%A new method of productivity prediction for high CO2-content gas wells

    Institute of Scientific and Technical Information of China (English)

    严谨; 刘传喜

    2011-01-01

    Productivity of gas wells in Songnan volcanic gas reservoir is difficult to predict as high CO2 content has great influences on PVT of natural gas, resulting in large difference between the measured and predicted productivity. Based on laboratory experiments, this paper studied the effects of temperature, pressure and CO2 content on PVT of gas with high CO2 content and established the relational expressions of gas viscosity and Z-facto to pressure for gas with different CO2 contents. A new prediction model considering PVT variations of gas with high CO2 content was built based on gas percolation theory. The case study results indicate that the productivity reduces with the CO2 content increasing; the effect of Μz factor changes on productivity prediction should be considered when CO2 content is above 20 %; and the impacts of CO2 content on productivity lowers to a level that can be neglect in late production period. The new method is accurate and practical for the high CO2-content gas reservoirs.%松南火山岩气藏高含CO2,这种气体的存在对天然气的高压物性产生很大影响,使得气井产能预测与实际相差较大.在高含CO2气体高压物性分析(PVT)实验的基础上,研究了温度、压力和CO2含量对天然气高压物性参数的影响规律,建立了不同CO2含量下天然气粘度和偏差因子与压力的相关关系,并结合气体渗流理论建立了考虑高含CO2天然气高压物性变化的产能预测新模型.实例计算表明:①气井产能随着CO2含量的增高而降低;②当CO2含量大于20%时,气井产能评价必须考虑μΖ值(天然气粘度与偏差因子的乘积)变化的影响;③开发中后期可以忽略CO2含量对气井产能的影响.新的产能计算方法能反映CO2含量对产能计算的影响,精确度更高,对于高含CO2天然气田的产能评价和生产制度的制定具有重要的指导意义.

  20. Origin of CO2 in natural gas from the Triassic Feixianguan Formation of Northeast Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The natural gas from the Triassic Feixianguan Formation of Northeast Sichuan Basin contains high H2S whereas relatively low CO2 concentrations and the CO2 display high δ13C values (ranging from -5.81‰ to 3.3‰ (PDB)). This seems to contradict the conventional wisdom that TSR should be a primary source of CO2 in natural gas from the Feixianguan Formation. In contrast, many authigenic calcite samples from these sites display very low δ13C values (ranging from -18.4‰ to -10.3‰ (PDB)). This suggests that the carbon from TSR source dominated the formation of calcite whereas the carbon from inorganic source came into CO2 in natural gas. In order to assess the origin of CO2 from these H2S-rich sites, we have calculated the relative contributions of organic and inorganic carbon sources to the CO2 and authigenic calcite. The organic carbon source possibly originated from TSR, whereas the inorganic one might be generated from marine carbonates dissolution. This calculation is based on the carbon isotopic compositions of CO2 and authigenic calcite as well as an isotopic mass balance. The results show that the contribution of organic carbon source to the CO2 is only 2%, whereas that to authigenic calcite is as high as 43% on average. Such results combined with thermodynamic evidence indicate that the isotopically light CO2 produced by TSR process may contribute to authigenic calcite precipitation during burial diagenesis. Distinguishable from Ordovician reservoir of Tarim Basin, Feixianguan reservoir of Northeast Sichuan Basin experienced rapid tectonic uplift due to Yanshanian movement after TSR occurred. Such tectonic event could induce temperature decrease and further promote carbonates dissolution. During these processes, secondary porosity has developed in Feixianguan carbonate reservoirs. Therefore, much attention should be paid to the structural highs in search of high quality carbonate reservoirs.

  1. Long-wave infrared imaging of vegetation for detecting leaking CO2 gas

    Science.gov (United States)

    Johnson, Jennifer E.; Shaw, Joseph A.; Lawrence, Rick; Nugent, Paul W.; Dobeck, Laura M.; Spangler, Lee H.

    2012-01-01

    The commercial development of uncooled-microbolometer, long-wave infrared (LWIR) imagers, combined with advanced radiometric calibration methods developed at Montana State University, has led to new uses of thermal imagery in remote sensing applications. One specific novel use of these calibrated imagers is imaging of vegetation for CO2 gas leak detection. During a four-week period in the summer of 2011, a CO2 leak was simulated in a test field run by the Zero Emissions Research and Technology Center in Bozeman, Montana. An LWIR imager was deployed on a scaffold before and during the CO2 release, viewing a vegetation test area that included regions of high and low CO2 flux. Increased root-level CO2 concentration caused plant stress that led to reduced thermal regulation of the vegetation, which was consistent with increased diurnal variation of IR emission observed in this study. In a linear regression, the IR data were found to have a strong relationship to the CO2 emission and to be consistent with the location of leaking CO2 gas. Reducing the continuous data set to one image per day weakened the regression fit, but maintained sufficient significance to indicate that this method could be implemented with once-daily airborne images.

  2. CO2 recycling by means of reforming of coke oven gas for methanol production

    Directory of Open Access Journals (Sweden)

    J. M. Bermúdez

    2013-01-01

    Full Text Available The steelmaking industry is the largest energyconsuming manufacturing sector. As a consequence of this, the CO2 emissions from this sector account for about 5-7 % of the total anthropogenic CO2 emissions. For this reason, increasing efforts are being made to find solutions that might help diminish these emissions and increase energy efficiency. A better management of the coke oven gas (COG surplus is one of the proposed solutions...

  3. Early results from the development of a miniature tunable diode laser gas cell for measuring CO2 isotopologue fluxes in situ

    Science.gov (United States)

    Osuna, J. L.; Bora, M.; Bond, T.; Wharton, S.

    2014-12-01

    In order to accurately predict how ecosystems will respond to climate change, it is necessary to separate the response of respiration and photosynthetic uptake individually to environmental conditions. Currently, the net ecosystem exchange of CO2 is measured continuously at various ecosystems around the world. Net CO­2 flux can be partitioned into the primary components using either models or measurements of 13C/12C in the CO2 flux. We introduce recent technological developments toward in situ, rapid, continuous measurements of fluxes of 13CO2 and 12CO2. We describe a unique approach to achieving 10Hz measurements of CO2 using tunable diode laser gas absorption spectroscopy in a multi-pass White cell capable of being deployed directly to a canopy. We will first discuss proof-of-concept characterization of the technique using wave modulation spectroscopy with a laser tuned to detect 12CO2 fluxes. We show the sensitivity of the 2w component of a wave-modulated signal to CO2 concentration, the precision, and the accuracy of the sensor as well as the stability of the sensor under normal ranges of ambient temperature and humidity in an environmental chamber. We then show preliminary results of sensor performance with a laser tuned to measure 13CO2 and 12CO2 fluxes. We discuss our approach to reliably measuring multiple peaks of gas absorption while maintaining the rapid sampling rates necessary for flux calculations. We will also discuss considerations for extending the sensor from the lab to being directly deployed into a canopy for in situ measurements. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS- 658355

  4. Effects of flue gas compositions on nitrosamine and nitramine formation in postcombustion CO2 capture systems.

    Science.gov (United States)

    Dai, Ning; Mitch, William A

    2014-07-01

    Amine-based technologies are emerging as the prime contender for postcombustion CO2 capture. However, concerns have arisen over the health impacts of amine-based CO2 capture associated with the release of nitrosamines and nitramines, which are byproducts from the reactions between flue gas NOx and solvent amines. In this study, flue gas compositions were systematically varied to evaluate their effects on the formation of nitrosamines and nitramines in a lab-scale CO2 capture reactor with morpholine as a model solvent amine. The accumulation of N-nitrosomorpholine in both the absorber and washwater increased linearly with both NO and NO2 for concentrations up to ∼20 ppmv. These correlations could be extrapolated to estimate N-nitrosomorpholine accumulation at extremely low NOx levels (0.3 ppmv NO2 and 1.5 ppmv NO). NO played a particularly important role in driving N-nitrosomorpholine formation in the washwater, likely following partial oxidation to NO2 by O2. The accumulation of N-nitromorpholine in both the absorber and washwater positively correlated with flue gas NO2 concentration, but not with NO concentration. Both N-nitrosomorpholine and N-nitromorpholine accumulated fastest in the absence of CO2. Flue gas humidity did not affect nitrosamine accumulation in either the absorber or the washwater unit. These results provide a basis for estimating the effects of flue gas composition on nitrosamine and nitramine accumulation in postcombustion CO2 capture systems.

  5. Compact portable QEPAS multi-gas sensor

    Science.gov (United States)

    Dong, Lei; Kosterev, Anatoliy A.; Thomazy, David; Tittel, Frank K.

    2011-01-01

    A quartz-enhanced photoacoustic spectroscopy (QEPAS) based multi-gas sensor was developed to quantify concentrations of carbon monoxide (CO), hydrogen cyanide (HCN), hydrogen chloride (HCl), and carbon dioxide (CO2) in ambient air. The sensor consists of a compact package of dimensions 25cm x 25cm x 10cm and was designed to operate at atmospheric pressure. The HCN, CO2, and HCl measurement channels are based on cw, C-band telecommunication-style packaged, fiber-coupled diode lasers, while the CO channel uses a TO can-packaged Sb diode laser as an excitation source. Moreover, the sensor incorporates rechargeable batteries and can operate on batteries for at least 8 hours. It can also operate autonomously or interact with another device (such as a computer) via a RS232 serial port. Trace gas detection limits of 7.74ppm at 4288.29cm-1 for CO, 450ppb at 6539.11 cm-1 for HCN, 1.48ppm at 5739.26 cm-1 for HCl and 97ppm at 6361.25 cm-1 for CO2 for a 1sec average time, were demonstrated.

  6. Proportional counters aged anode wire recovering using an 80%CF4 + 20%CO2 gas mixture

    CERN Document Server

    Gavrilov, Gennady; Conti, Richard; Fetisov, Andrey; Maysuzenko, Dmitry; Shvecova, Natalia; Vakhtel, Victor

    2011-01-01

    A technique to recover a gas proportional counter having an aged anode wire using a glow discharge in an 80%CF4 + 20%CO2 gas mixture has been developed and tested. Studies of aging effects were carried out under sustained irradiation by an intense 90Sr -source of the straw proportional counters operated with a 60%Ar + 30%CO2 + 10%CF4 gas mixture. Special attention was paid to the aging mechanism of the anode wires. Our experience showed that using a given gas mixture the swelling of the anode wires is a typical mode of aging that leads to degradation of the gas gain. The proposed method of recovery provided a complete restoration of the gas gain and the signal amplitude in the damaged zone of the wire. SEM/XEM analysis confirmed successful cleaning WOx deposits from the wire surface. The application of this method to recover the aged gaseous detectors in real experimental conditions is discussed.

  7. Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology

    Science.gov (United States)

    Chullen, Cinda

    2015-01-01

    Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology" project will investigate newly developed optic gas sensors delivered from a Small Business Innovative Research (SBIR) Phase II effort. A ventilation test rig will be designed and fabricated to test the sensors while integrated with a Suited Manikin Test Apparatus (SMTA). Once the sensors are integrated, a series of test points will be completed to verify that the sensors can withstand Advanced Suit Portable Life Support System (PLSS) environments and associated human metabolic profiles for changes in pressure and levels of Oxygen (ppO2), carbon dioxide (ppCO2), and humidity (ppH2O).

  8. Fabrication quality analysis of a fiber optic refractive index sensor created by CO2 laser machining.

    Science.gov (United States)

    Chen, Chien-Hsing; Yeh, Bo-Kuan; Tang, Jaw-Luen; Wu, Wei-Te

    2013-03-26

    This study investigates the CO2 laser-stripped partial cladding of silica-based optic fibers with a core diameter of 400 μm, which enables them to sense the refractive index of the surrounding environment. However, inappropriate treatments during the machining process can generate a number of defects in the optic fiber sensors. Therefore, the quality of optic fiber sensors fabricated using CO2 laser machining must be analyzed. The results show that analysis of the fiber core size after machining can provide preliminary defect detection, and qualitative analysis of the optical transmission defects can be used to identify imperfections that are difficult to observe through size analysis. To more precisely and quantitatively detect fabrication defects, we included a tensile test and numerical aperture measurements in this study. After a series of quality inspections, we proposed improvements to the existing CO2 laser machining parameters, namely, a vertical scanning pathway, 4 W of power, and a feed rate of 9.45 cm/s. Using these improved parameters, we created optical fiber sensors with a core diameter of approximately 400 μm, no obvious optical transmission defects, a numerical aperture of 0.52 ± 0.019, a 0.886 Weibull modulus, and a 1.186 Weibull-shaped parameter. Finally, we used the optical fiber sensor fabricated using the improved parameters to measure the refractive indices of various solutions. The results show that a refractive-index resolution of 1.8 × 10(-4) RIU (linear fitting R2 = 0.954) was achieved for sucrose solutions with refractive indices ranging between 1.333 and 1.383. We also adopted the particle plasmon resonance sensing scheme using the fabricated optical fibers. The results provided additional information, specifically, a superior sensor resolution of 5.73 × 10(-5) RIU, and greater linearity at R2 = 0.999.

  9. On which timescales do gas transfer velocities control North Atlantic CO2 flux variability?

    Science.gov (United States)

    Couldrey, Matthew P.; Oliver, Kevin I. C.; Yool, Andrew; Halloran, Paul R.; Achterberg, Eric P.

    2016-05-01

    The North Atlantic is an important basin for the global ocean's uptake of anthropogenic and natural carbon dioxide (CO2), but the mechanisms controlling this carbon flux are not fully understood. The air-sea flux of CO2, F, is the product of a gas transfer velocity, k, the air-sea CO2 concentration gradient, ΔpCO2, and the temperature- and salinity-dependent solubility coefficient, α. k is difficult to constrain, representing the dominant uncertainty in F on short (instantaneous to interannual) timescales. Previous work shows that in the North Atlantic, ΔpCO2 and k both contribute significantly to interannual F variability but that k is unimportant for multidecadal variability. On some timescale between interannual and multidecadal, gas transfer velocity variability and its associated uncertainty become negligible. Here we quantify this critical timescale for the first time. Using an ocean model, we determine the importance of k, ΔpCO2, and α on a range of timescales. On interannual and shorter timescales, both ΔpCO2 and k are important controls on F. In contrast, pentadal to multidecadal North Atlantic flux variability is driven almost entirely by ΔpCO2; k contributes less than 25%. Finally, we explore how accurately one can estimate North Atlantic F without a knowledge of nonseasonal k variability, finding it possible for interannual and longer timescales. These findings suggest that continued efforts to better constrain gas transfer velocities are necessary to quantify interannual variability in the North Atlantic carbon sink. However, uncertainty in k variability is unlikely to limit the accuracy of estimates of longer-term flux variability.

  10. Recovery Act: Innovative CO2 Sequestration from Flue Gas Using Industrial Sources and Innovative Concept for Beneficial CO2 Use

    Energy Technology Data Exchange (ETDEWEB)

    Dando, Neal; Gershenzon, Mike; Ghosh, Rajat

    2012-07-31

    field testing of a biomimetic in-duct scrubbing system for the capture of gaseous CO2 coupled with sequestration of captured carbon by carbonation of alkaline industrial wastes. The Phase 2 project, reported on here, combined efforts in enzyme development, scrubber optimization, and sequestrant evaluations to perform an economic feasibility study of technology deployment. The optimization of carbonic anhydrase (CA) enzyme reactivity and stability are critical steps in deployment of this technology. A variety of CA enzyme variants were evaluated for reactivity and stability in both bench scale and in laboratory pilot scale testing to determine current limits in enzyme performance. Optimization of scrubber design allowed for improved process economics while maintaining desired capture efficiencies. A range of configurations, materials, and operating conditions were examined at the Alcoa Technical Center on a pilot scale scrubber. This work indicated that a cross current flow utilizing a specialized gas-liquid contactor offered the lowest system operating energy. Various industrial waste materials were evaluated as sources of alkalinity for the scrubber feed solution and as sources of calcium for precipitation of carbonate. Solids were mixed with a simulated sodium bicarbonate scrubber blowdown to comparatively examine reactivity. Supernatant solutions and post-test solids were analyzed to quantify and model the sequestration reactions. The best performing solids were found to sequester between 2.3 and 2.9 moles of CO2 per kg of dry solid in 1-4 hours of reaction time. These best performing solids were cement kiln dust, circulating dry scrubber ash, and spray dryer absorber ash. A techno-economic analysis was performed to evaluate the commercial viability of the proposed carbon capture and sequestration process in full-scale at an aluminum smelter and a refinery location. For both cases the in-duct scrubber technology was compared to traditional amine- based capture

  11. Thermodynamic Analysis and Experimental Study on Reaction of CO2 Gas with Hot Metal

    Institute of Scientific and Technical Information of China (English)

    Guo WEI; Zhi-tao LI; Zi-liang LI; Qiang-jian GAO; Feng-man SHEN

    2016-01-01

    The reaction of CO2 gas with hot metal was investigated based on the thermodynamic analysis and experi-mental results.It shows that both silicon and carbon in hot metal can be oxidized by CO2 gas in the temperature range of 1 300-1 500 ℃.When using graphite crucible,temperature has little influence on final mass percent of car-bon w[C] because of the carburization effect.Decarburization degree rises significantly with increasing gas inj ection rate and w[C] can be reduced to 3�2% at most when using MgO crucible.Lower temperature or higher gas inj ection rate is propitious to promote desilication reaction,but only 5%-10% of desilication ratio could be obtained in 20 min. The final mass percent of silicon w[Si] when using MgO crucible is lower than that when using graphite crucible.Ex-perimental results also demonstrate that CO2 injection has no effect on the concentration of manganese,sulfur and phosphorus in hot metal.In view of the weak oxidation ability and temperature drop of hot metal,CO2 gas is sugges-ted to be used as carrier gas in desilication process rather than oxidizing agent.

  12. CO2地质封存和提高天然气采收率%Geological Storage of CO2 and Enhanced Gas Recovery

    Institute of Scientific and Technical Information of China (English)

    孙晓岭; 曾凡桂; 刘贺娟

    2012-01-01

    The CCS technology (CO2 capture and storage)that was addressed by developed countries , such as USA, Canada, Germany, Holland and so on demonstrating that the C02 can be injected underground or deep sea to reduce the emission of CO2 into atmosphere. These sites include saline aquifer, unmineral coal seam (CO2—ECBM), depleted oil or gas field (CO2-EOR/EGR). The CCS technology seems like become the most important way to solve the CO2 emission problem and at the same time, which can also produce some commercial belief. In this paper, as one kind of the CCS technology, CO2-EGR technology has been summarized, including the projects in the world, the critical issues, challenges and the prospect.%目前发达国家,如美国、加拿大、德国、荷兰等兴起的CCS(CO2 capture and storage)技术,即将CO2储存到地下或深海中,包括盐水层、不可开采煤层(CO2-ECBM)、废弃油田(CO2-EOR)、废弃气田(CO2-EGR),已成为解决CO2排放和保护环境的重要举措,而且也可能产生相应的商业利益.本文从CO2提高天然气的采收率角度就这一技术进行概括,研究世界上该类工程的开展情况、技术的关键问题、面临的挑战以及发展前景.

  13. CO2 migration in the vadose zone: experimental and numerical modelling of controlled gas injection

    Science.gov (United States)

    gasparini, andrea; credoz, anthony; grandia, fidel; garcia, david angel; bruno, jordi

    2014-05-01

    The mobility of CO2 in the vadose zone and its subsequent transfer to the atmosphere is a matter of concern in the risk assessment of the geological storage of CO2. In this study the experimental and modelling results of controlled CO2 injection are reported to better understanding of the physical processes affecting CO2 and transport in the vadose zone. CO2 was injected through 16 micro-injectors during 49 days of experiments in a 35 m3 experimental unit filled with sandy material, in the PISCO2 facilities at the ES.CO2 centre in Ponferrada (North Spain). Surface CO2 flux were monitored and mapped periodically to assess the evolution of CO2 migration through the soil and to the atmosphere. Numerical simulations were run to reproduce the experimental results, using TOUGH2 code with EOS7CA research module considering two phases (gas and liquid) and three components (H2O, CO2, air). Five numerical models were developed following step by step the injection procedure done at PISCO2. The reference case (Model A) simulates the injection into a homogeneous soil(homogeneous distribution of permeability and porosity in the near-surface area, 0.8 to 0.3 m deep from the atmosphere). In another model (Model B), four additional soil layers with four specific permeabilities and porosities were included to predict the effect of differential compaction on soil. To account for the effect of higher soil temperature, an isothermal simulation called Model C was also performed. Finally, the assessment of the rainfall effects (soil water saturation) on CO2 emission on surface was performed in models called Model D and E. The combined experimental and modelling approach shows that CO2 leakage in the vadose zone quickly comes out through preferential migration pathways and spots with the ranges of fluxes in the ground/surface interface from 2.5 to 600 g·m-2·day-1. This gas channelling is mainly related to soil compaction and climatic perturbation. This has significant implications to

  14. Interdisciplinary Investigation of CO2 Sequestration in Depleted Shale Gas Formations

    Energy Technology Data Exchange (ETDEWEB)

    Zoback, Mark D. [Stanford Univ., CA (United States); Kovscek, Anthony R. [Stanford Univ., CA (United States); Wilcox, Jennifer [Stanford Univ., CA (United States)

    2013-09-30

    This project investigates the feasibility of geologic sequestration of CO2 in depleted shale gas reservoirs from an interdisciplinary viewpoint. It is anticipated that over the next two decades, tens of thousands of wells will be drilled in the 23 states in which organic-rich shale gas deposits are found. This research investigates the feasibility of using these formations for sequestration. If feasible, the number of sites where CO2 can be sequestered increases dramatically. The research embraces a broad array of length scales ranging from the ~10 nanometer scale of the pores in the shale formations to reservoir scale through a series of integrated laboratory and theoretical studies.

  15. Tail gas treatment of SEWGS technology. Literature review on CO2 and H2S separation

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, E.N.; Van Dijk, H.A.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2011-12-15

    This literature review is the result of an investigation of the most important way to remove sulphur for the last decades. We will discuss Claus and Claus tail gas process options to solve the problem. Next to solutions which come from membranes, direct oxidation catalysis, from acid gas removal technology, sorbent technology, and liquid oxidation. Each field will be described and explained to understand in which way it could be suitable to separate CO2 and H2S and reach our goals with regard to CO2 transport and storage conditions. Finally, the target of this work will be to propose some interesting and promising solutions in view of future experiments.

  16. Development of a fiber optic sensor for measurement of pCO 2 in sea water: design criteria and sea trials

    Science.gov (United States)

    Goyet, Catherine; Walt, David R.; Brewer, Peter G.

    1992-06-01

    Measurement of the partial pressure of CO 2 gas in sea water (pCO 2) is usually accomplished by gas chromatography or infrared spectrometry. Both techniques require large, complex and power-demanding apparatus. In this paper we explore the possibility of developing small, low-power sensors. We have developed and tested a prototype pCO 2 sensor for seawater based upon the fluorescence of a combination of dyes encapsulated within a gas permeable silicone membrane at the tip of a single optical fiber. The optical module (Douglas Instruments) delivers 30 Hz chopped white light to a filter and is passed through a dichroic mirror. This light is then focused on to a 220 μm optical fiber. The fiber, approximately 2 m long, was terminated with a standard coupler equipped with a small silicone nipple. The internal volume of the sensor tip (about 10 μl) was filled with a combination of a fluorescent indicator and two absorbing dyes so as to achieve the required sensitivity. HPTS (hydroxypyrenetrisulfonic acid) was chosen as the fluorescent species; Neutral Red and DNPA (2-(2,4-dinitrophenylazo)-1-naphthol-3,6-disulfonic acid) were selected as absorbers. Illumination at λex = 450 nm yielded fluorescence at λex = 530 nm, and fluoresced light was returned through the same fiber, reflected at 90° by the dichroic mirror, passed through an interference filter and focused on to a sensitive silicon photodiode. Experiments carried out both in the laboratory on standard solutions and at sea show a precision of 3% in the range 400-500 ppm pCO 2. To our knowledge, this is the first demonstration of an optical pCO 2 sensor for detecting oceanic signals. This technology is complementary to optical detection of pH and points the way towards full characterization of the CO 2 system within this measurement framework.

  17. Synthesis, characterization and enhanced gas sensing performance of porous ZnCo2O4 nano/microspheres.

    Science.gov (United States)

    Liu, Tie; Liu, Jingyuan; Liu, Qi; Song, Dalei; Zhang, Hongseng; Zhang, Hongquan; Wang, Jun

    2015-12-14

    In recent years, spinel-type compounds have attracted great interest because of their gem-like qualities. However, little is known of their gas sensing properties. We report, in this paper, on a self-assembly method to prepare porous ZnCo2O4 (ZCO) nano/microspheres by a facile one-step solvothermal process and subsequent annealing. Abundant techniques were used to characterize the morphology and structure of the as-obtained compounds. Our data indicate that the hierarchical nano/microspheres are constructed from numerous nanoparticles primarily, which have a higher specific surface area (ca. 77.3 m(2) g(-1)) and are of uniform diameter (ca. 1 μm). To demonstrate their potential application, gas sensors based on the as-synthesized ZCO nano/microspheres were fabricated to test their sensing performance, whose sensing behaviours correspond to p-type semiconductors. The test results also indicate that porous spinel-type compounds have an excellent kinetic response to ethanol at an operating temperature of 175 °C and a superior selectivity. As such, hierarchical porous ZnCo2O4 nano/microspheres will hold promising potential in the gas sensor field.

  18. The Strategy and Technology Selection for Non-CO2 Greenhouse Gas Emission Control

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ya-Min; FENG Yong-Sheng

    2014-01-01

    The emission control of non-CO2 greenhouse gases is conducive to slowing down global warming. It is also helpful in controlling environmental pollution, and beneficial in improving the local health benefits. This paper aims at six kinds of non-CO2 greenhouse gases under United Nations Framework Convention on Climate Change, namely methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). This paper analyzes the emission status and trend of China’s non-CO2 greenhouse gases, and provides some technology selections for non-CO2 emission reduction. Through strategic policy arrangements and appropriate technology choices, China can gain environmental protection and greenhouse gas control.

  19. Amino acid salt solutions as solvents in CO2 capture from flue gas

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai; Thomsen, Kaj; Stenby, Erling Halfdan

    solutions is their ability to form solid precipitates upon the absorption of CO2. The occurrence of crystallization offers the possibility of increasing the CO2 loading capacity of the solvent. However, precipitation can also have negative effect on the CO2 capture process. The chemical nature of the solid...... loading capacity of aqueous solutions of the potassium salts of selected amino-acids (glycine, taurine, lysine proline, and glutamic acid) were examined, and the relation between the initial amino acid salt concentration and precipitation ability of each solution were determined. Experiments were...... of glycine, taurine, and lysine, while in the case of proline, and glutamic acid, the precipitate was found to be bicarbonate. These results give an important contribution to further understanding the potential of amino acid salt solutions in CO2 capture from flue gas....

  20. A Low-Cost Fluorescent Sensor for pCO2 Measurements

    Directory of Open Access Journals (Sweden)

    Xudong Ge

    2014-04-01

    Full Text Available Global warming is believed to be caused by increasing amounts of greenhouse gases (mostly CO2 discharged into the environment by human activity. In addition to an increase in environmental temperature, an increased CO2 level has also led to ocean acidification. Ocean acidification and rising temperatures have disrupted the water’s ecological balance, killing off some plant and animal species, while encouraging the overgrowth of others. To minimize the effect of global warming on local ecosystem, there is a strong need to implement ocean observing systems to monitor the effects of anthropogenic CO2 and the impacts thereof on ocean biological productivity. Here, we describe the development of a low-cost fluorescent sensor for pCO2 measurements. The detector was exclusively assembled with low-cost optics and electronics, so that it would be affordable enough to be deployed in great numbers. The system has several novel features, such as an ideal 90° separation between excitation and emission, a beam combiner, a reference photodetector, etc. Initial tests showed that the system was stable and could achieve a high resolution despite the low cost.

  1. CO2 Sensors Based on Nanocrystalline SnO2 Doped with CuO

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Liu, Chung Chiun; Ward, Benjamin J.

    2008-01-01

    Nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been found to be useful as an electrical-resistance sensory material for measuring the concentration of carbon dioxide in air. SnO2 is an n-type semiconductor that has been widely used as a sensing material for detecting such reducing gases as carbon monoxide, some of the nitrogen oxides, and hydrocarbons. Without doping, SnO2 usually does not respond to carbon dioxide and other stable gases. The discovery that the electrical resistance of CuO-doped SnO2 varies significantly with the concentration of CO2 creates opportunities for the development of relatively inexpensive CO2 sensors for detecting fires and monitoring atmospheric conditions. This discovery could also lead to research that could alter fundamental knowledge of SnO2 as a sensing material, perhaps leading to the development of SnO2-based sensing materials for measuring concentrations of oxidizing gases. Prototype CO2 sensors based on CuO-doped SnO2 have been fabricated by means of semiconductor-microfabrication and sol-gel nanomaterial-synthesis batch processes that are amendable to inexpensive implementation in mass production.

  2. Synthesis, Characterization, and Sensor Applications of Spinel ZnCo2O4 Nanoparticles

    Science.gov (United States)

    Morán-Lázaro, Juan Pablo; López-Urías, Florentino; Muñoz-Sandoval, Emilio; Blanco-Alonso, Oscar; Sanchez-Tizapa, Marciano; Carreon-Alvarez, Alejandra; Guillén-Bonilla, Héctor; Olvera-Amador, María de la Luz; Guillén-Bonilla, Alex; Rodríguez-Betancourtt, Verónica María

    2016-01-01

    Spinel ZnCo2O4 nanoparticles were synthesized by means of the microwave-assisted colloidal method. A solution containing ethanol, Co-nitrate, Zn-nitrate, and dodecylamine was stirred for 24 h and evaporated by a microwave oven. The resulting solid material was dried at 200 °C and subsequently calcined at 500 °C for 5 h. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy, confirming the formation of spinel ZnCo2O4 nanoparticles with average sizes between 49 and 75 nm. It was found that the average particle size decreased when the dodecylamine concentration increased. Pellets containing ZnCo2O4 nanoparticles were fabricated and tested as sensors in carbon monoxide (CO) and propane (C3H8) gases at different concentrations and temperatures. Sensor performance tests revealed an extremely high response to 300 ppm of CO at an operating temperature of 200 °C. PMID:27999315

  3. Measurement of air exchange rates in different indoor environments using continuous CO2 sensors

    Institute of Scientific and Technical Information of China (English)

    Yan YOU; Can Niu; Jian Zhou; Yating Liu; Zhipeng Bai; Jiefeng Zhang; Fei He; Nan Zhang

    2012-01-01

    A new air exchange rate (AER) monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies.Controlled laboratory simulation tests were conducted in a 1-m3 environmental chamber at different AERs (0.1-10.0 hr-1).AERs were determined using the decay method based on box model assumptions.Field tests were conducted in classrooms,dormitories,meeting rooms and apartments during 2-5 weekdays using CO2 sensors coupled with data loggers.Indoor temperature,relative humidity (RH),and CO2 concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded.Statistical results indicated that good laboratory performance was achieved:duplicate precision was within 10%,and the measured AERs were 90%-120% of the real AERs.Average AERs were 1.22,1.37,1.10,1.91 and 0.73 hr-1 in dormitories,air-conditioned classrooms,classrooms with an air circulation cooling system,reading rooms,and meeting rooms,respectively.In an elderly particulate matter exposure study,all the homes had AER values ranging from 0.29 to 3.46 hr-1 in fall,and 0.12 to 1.39 hr-1 in winter with a median AER of 1.15.

  4. Synthesis, Characterization, and Sensor Applications of Spinel ZnCo2O4 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Juan Pablo Morán-Lázaro

    2016-12-01

    Full Text Available Spinel ZnCo2O4 nanoparticles were synthesized by means of the microwave-assisted colloidal method. A solution containing ethanol, Co-nitrate, Zn-nitrate, and dodecylamine was stirred for 24 h and evaporated by a microwave oven. The resulting solid material was dried at 200 °C and subsequently calcined at 500 °C for 5 h. The samples were characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and Raman spectroscopy, confirming the formation of spinel ZnCo2O4 nanoparticles with average sizes between 49 and 75 nm. It was found that the average particle size decreased when the dodecylamine concentration increased. Pellets containing ZnCo2O4 nanoparticles were fabricated and tested as sensors in carbon monoxide (CO and propane (C3H8 gases at different concentrations and temperatures. Sensor performance tests revealed an extremely high response to 300 ppm of CO at an operating temperature of 200 °C.

  5. CO2传感器的制作及特性%Fabrication of CO2 sensor and its characteristic

    Institute of Scientific and Technical Information of China (English)

    全宝富; 张爽; 刘晓宁; 陈丽华; 刘奎学

    2002-01-01

    采用高温固相反应法制备了Na超离子导体(NASICON)的固体电解质材料,用IR技术分析了不同合成温度下制备的NASICON材料的基本性质.用所制得的NASICON材料制作了具有较高灵敏度和选择性的CO2气体传感器.

  6. CO2 capture from simulated fuel gas mixtures using semiclathrate hydrates formed by quaternary ammonium salts.

    Science.gov (United States)

    Park, Sungwon; Lee, Seungmin; Lee, Youngjun; Seo, Yongwon

    2013-07-02

    In order to investigate the feasibility of semiclathrate hydrate-based precombustion CO2 capture, thermodynamic, kinetic, and spectroscopic studies were undertaken on the semiclathrate hydrates formed from a fuel gas mixture of H2 (60%) + CO2 (40%) in the presence of quaternary ammonium salts (QASs) such as tetra-n-butylammonium bromide (TBAB) and fluoride (TBAF). The inclusion of QASs demonstrated significantly stabilized hydrate dissociation conditions. This effect was greater for TBAF than TBAB. However, due to the presence of dodecahedral cages that are partially filled with water molecules, TBAF showed a relatively lower gas uptake than TBAB. From the stability condition measurements and compositional analyses, it was found that with only one step of semiclathrate hydrate formation with the fuel gas mixture from the IGCC plants, 95% CO2 can be enriched in the semiclathrate hydrate phase at room temperature. The enclathration of both CO2 and H2 in the cages of the QAS semiclathrate hydrates and the structural transition that results from the inclusion of QASs were confirmed through Raman and (1)H NMR measurements. The experimental results obtained in this study provide the physicochemical background required for understanding selective partitioning and distributions of guest gases in the QAS semiclathrate hydrates and for investigating the feasibility of a semiclathrate hydrate-based precombustion CO2 capture process.

  7. An approach to utilize a grid of EMF potentiometric CO 2 sensors in a ultra low power wireless sensor networ k

    NARCIS (Netherlands)

    Bent, J.F. van der; Rijn, C.F.M. van; Puik, Erik

    2010-01-01

    from the article: The demand for a wireless CO2 solution is ever increasing. One of the biggest problems with the majority of commercial available CO2 sensors is the high energy consumption which makes them unsuitable for battery operation. Possible candidates for CO2 se

  8. Review of the impacts of leaking CO 2 gas and brine on groundwater quality

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla P.; Lawter, Amanda R.; Bacon, Diana H.; Zheng, Liange; Kyle, Jennifer; Brown, Christopher F.

    2017-06-01

    This review paper provides a synthetic view of the existing knowledge and summarizes data and findings of the recent literature on the subject of the potential leaking of CO2 from the deep subsurface storage reservoirs and the effects on aquifer quality. New ideas and concepts are developed and insights are also provided. The objectives of this paper are to: 1) present and discuss potential risks for groundwater degradation due to CO2 gas and brine exposure; 2) identify the set of geochemical data required to assess and predict aquifer responses to CO2 and brine leakage. Specifically, this paper will discuss the following issues: 1) Aquifer responses (such as changes in aqueous phase/groundwater chemical composition; changes in solid phase chemistry and mineralogy; changes in the extent and rate of reactions and processes and possible establishment of a new network of reactions and processes affecting or controlling overall mobility of major, minor, and trace elements; development of conceptual and reduced order models (ROMs) to describe and predict aquifer responses); 2) The degree of impact such as significant or insignificant changes in pH and major, minor, and trace element release that depend on the following controlling variables; the effect of leaking plume characteristics (gas composition, pure CO2 and/or CO2 -CH4 -H2S mixtures and brine concentration and composition (trace metals); aquifer properties [such as initial aqueous phase conditions and mineralogy: minerals controlling sediments’ response (e.g., calcite, Si bearing minerals, etc.)]; overview of relevant hydrogeological and geochemical processes related to the impact of CO2 gas and brine on groundwater quality; the fate of the elements released from sediments or transported with brine (such as precipitation/incorporation into minerals (calcite and other minerals), adsorption, electron transfer reactions, the role of natural attenuation; whether or not the release of metals following exposure to

  9. COMPARISON OF CO2-EMISSIONS OF HOUSEHOLDS HEATED BY NATURAL GAS AND FIREWOOD

    Directory of Open Access Journals (Sweden)

    MÓNIKA PALÁDI

    2013-12-01

    Full Text Available In terms of climate protection, one of the most important questions is the reduction of the GHG emission. In this study, I compared CO2 -emission of households heated by natural gas and firewood, which had similar heated area and volume of air, considering the carbon-dioxide absorbing of forests of the households heated by firewood. Natural gas is a fossil fuel; however, the firewood (solid biomass is a renewable energy resource. One of the main features of renewable energy sources is to get into the atmosphere less CO2 than fossil fuels. The renewable energy resources emit into the air just as much CO2 as they absorb during their life cycle.

  10. HEAT RECOVERY FROM A NATURAL GAS POWERED INTERNAL COMBUSTION ENGINE BY CO2 TRANSCRITICAL POWER CYCLE

    Directory of Open Access Journals (Sweden)

    Mahmood Farzaneh-Gord

    2010-01-01

    Full Text Available The present work provides details of energy accounting of a natural gas powered internal combustion engine and achievable work of a utilized CO2 power cycle. Based on experimental performance analysis of a new designed IKCO (Iran Khodro Company 1.7 litre natural gas powered engine, full energy accounting of the engine were carried out on various engine speeds and loads. Further, various CO2 transcritical power cycle configurations have been appointed to take advantages of exhaust and coolant water heat lost. Based on thermodynamic analysis, the amount of recoverable work obtainable by CO2 transcritical power cycles have been calculated on various engine conditions. The results show that as much as 18 kW power could be generated by the power cycle. This would be considerable amount of power especially if compared with the engine brake power.

  11. Oil drainage by CO2 gas diffusion, dissolution and foaming in heavy oil

    Energy Technology Data Exchange (ETDEWEB)

    Kono, H; Sasaki, K.; Sugai, Y. [Department of Earth Resources Engineering, Kyushu University (Japan); Takahashi, T.; Ito, D.; Okabe, T. [Research Center, JAPEX (Japan)

    2011-07-01

    In the heavy oil industry, the injection of carbon dioxide into reservoirs is used as a method to enhance oil recovery and store CO2. During this process, dissolution of gas takes place and contributes to cold production through a reduction in oil viscosity and capillarity pressure and swelling of the oil. The aim of this study was to investigate oil drainage from the sandstone cores. Experiments were conducted in a high pressure cell with pressures up to 10MPa, to measure the swelling factors of heavy and light oils for CO2 gas dissolution and thus evaluate the swelling coefficient and diffusion coefficient of the oil. Results allowed the development of an equation to determine gas solubility in the heavy oil based on measurements of apparent density. This study showed that gas dissolution does not affect oil mobility but that foamy oil contributes to oil drainage.

  12. Flexible Transparent Electronic Gas Sensors.

    Science.gov (United States)

    Wang, Ting; Guo, Yunlong; Wan, Pengbo; Zhang, Han; Chen, Xiaodong; Sun, Xiaoming

    2016-07-01

    Flexible and transparent electronic gas sensors capable of real-time, sensitive, and selective analysis at room-temperature, have gained immense popularity in recent years for their potential to be integrated into various smart wearable electronics and display devices. Here, recent advances in flexible transparent sensors constructed from semiconducting oxides, carbon materials, conducting polymers, and their nanocomposites are presented. The sensing material selection, sensor device construction, and sensing mechanism of flexible transparent sensors are discussed in detail. The critical challenges and future development associated with flexible and transparent electronic gas sensors are presented. Smart wearable gas sensors are believed to have great potential in environmental monitoring and noninvasive health monitoring based on disease biomarkers in exhaled gas.

  13. Effects of CO2 gas as leaks from geological storage sites on agro-ecosystems

    DEFF Research Database (Denmark)

    Patil, Ravi; Colls, Jeremy J; Steven, Michael D

    2010-01-01

    Carbon capture and storage in geological formations has potential risks in the long-term safety because of the possibility of CO2 leakage. Effects of leaking gas, therefore, on vegetation, soil, and soil-inhabiting organisms are critical to understand. An artificial soil gassing and response...

  14. Phase equilibrium modeling of gas hydrate systems for CO2 capture

    DEFF Research Database (Denmark)

    Herslund, Peter Jørgensen; Thomsen, Kaj; Abildskov, Jens

    2012-01-01

    Two thermodynamic models capable of describing dissociation pressures of mixed gas clathrate hydrates formed from ternary mixtures of CO2, N2 and liquid water, are presented. Both of the models utilize the Cubic-Plus-Association (CPA) equation of state (EOS) for the thermodynamic description of t...

  15. Carbon Mineralization by Aqueous Precipitation for Beneficial Use of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Devenney, Martin; Gilliam, Ryan; Seeker, Randy

    2014-06-01

    The objective of this project is to demonstrate an innovative process to mineralize CO2 from flue gas directly to reactive carbonates and maximize the value and versatility of its beneficial use products. The program scope includes the design, construction, and testing of a CO2 Conversion to Material Products (CCMP) Pilot Demonstration Plant utilizing CO2 from the flue gas of a power production facility in Moss Landing, CA as well as flue gas from coal combustion. This topical report covers Phase 2b, which is the construction phase of pilot demonstration subsystems that make up the integrated plant. The subsystems included are the mineralization subsystem, the Alkalinity Based on Low Energy (ABLE) subsystem, the waste calcium oxide processing subsystem, and the fiber cement board production subsystem. The fully integrated plant is now capable of capturing CO2 from various sources (gas and coal) and mineralizing into a reactive calcium carbonate binder and subsequently producing commercial size (4ftx8ft) fiber cement boards. The topical report provides a description of the “as built” design of these subsystems and the results of the commissioning activities that have taken place to confirm operability. At the end of Phase 2b, the CCMP pilot demonstration is fully ready for testing.

  16. CO2 sensor versus Volatile Organic Compounds (VOC) sensor – analysis of field measurement data and implications for demand controlled ventilation

    DEFF Research Database (Denmark)

    Kolarik, Jakub

    2014-01-01

    and CO2 sensors, presence detection sensor and supply/return air flow were logged. VOC and CO2 signals were in agreement with respect to indicated need for mechanical ventilation for 49 % of occupied time (81 % of whole measuring period). VOC measurement would clearly trigger the mechanical ventilation...

  17. Exhaust Gas Recirculation in Gas Turbines for Reduction of CO2 Emissions; Combustion Testing with Focus on Stability and Emissions

    Directory of Open Access Journals (Sweden)

    Johan E. Hustad

    2005-12-01

    Full Text Available Exhaust gas recirculation can be applied with the intention of reducing CO2 emissions. When a fraction of the exhaust gas is injected in the entry of a gas turbine, the amount of CO2 in the exhaust gas not being recirculated will be higher and less complicated to capture. However, with this change in combustion air composition, especially the reduced concentration of oxygen, the combustion process will be affected. The lower oxygen concentration decreases the stability and the increased amount of CO2, H2O and N2 will decrease the combustion temperature and thus, the NOx emissions. Testing has been performed on a 65 kW gas turbine combustor, to investigate the effect of adding N2, CO2 and O2 in the combustion process, with focus on stability and emissions of NOx. Results show that adding N2 and CO2 decreases the NOx emissions, whereas O2 addition increases the NOx emissions. The tests have been performed both in a diffusion flame (pilot burner and a premixed flame (main burner, and for additives being injected with the fuel or with the air stream. Addition into the fuel stream is proven to affect the NOx emissions the most. The stability limits of the flames are indicated with respect to mass-based additive-to-fuel ratios.

  18. Numerical simulation of CO2 separation from gas mixtures in membrane modules: Effect of chemical absorbent

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Reza Razavi

    2016-01-01

    Full Text Available In this study, a mathematical model is proposed for prediction of CO2 absorption from N2/CO2 mixture by potassium threonate in a hollow-fiber membrane contactor (HFMC. CFD technique using numerical method of finite element was applied to solve the governing equations of model. Effect of different factors on CO2 absorption was analyzed and for investigation of absorbent type effect, functioning of potassium threonate was compared with diethanolamine (DEA. Axial and radial diffusion can be described with the two dimensional model established in this work. The obtained simulation results were compared with the reported experimental data to ensure accuracy of the model predictions. Comparison of model results with experimental data revealed that the developed model can well predict CO2 capture by potassium threonate in HFMCs. Increment of absorbent flow rate and concentration eventuate in enhancement of CO2 absorption. On the other hand, capture of CO2 will be reduced with increment of gas flow rate. According to the model results, potassium threonate can be considered as a more efficient absorbent as compared with DEA.

  19. Relationships between carbonyl sulfide (COS) and CO2 during leaf gas exchange.

    Science.gov (United States)

    Stimler, Keren; Montzka, Stephen A; Berry, Joseph A; Rudich, Yinon; Yakir, Dan

    2010-06-01

    *Carbonyl sulfide (COS) exchange in C(3) leaves is linked to that of CO(2), providing a basis for the use of COS as a powerful tracer of gross CO(2) fluxes between plants and the atmosphere, a critical element in understanding the response of the land biosphere to global change. *Here, we carried out controlled leaf-scale gas-exchange measurements of COS and CO(2) in representative C(3) plants under a range of light intensities, relative humidities and temperatures, CO(2) and COS concentrations, and following abscisic acid treatments. *No 'respiration-like' emission of COS or detectable compensation point, and no cross-inhibition effects between COS and CO(2) were observed. The mean ratio of COS to CO(2) assimilation flux rates, A(s)/A(c), was c. 1.4 pmol micromol(-1) and the leaf relative uptake (assimilation normalized to ambient concentrations, (A(s)/A(c))(C(a)(c)/C(a)(s))) was 1.6-1.7 across species and conditions, with significant deviations under certain conditions. Stomatal conductance was enhanced by increasing COS, which was possibly mediated by hydrogen sulfide (H(2)S) produced from COS hydrolysis, and a correlation was observed between A(s) and leaf discrimination against C(18)OO. *The results provide systematic and quantitative information necessary for the use of COS in photosynthesis and carbon-cycle research on the physiological to global scales.

  20. Kinetics of CH4 and CO2 hydrate dissociation and gas bubble evolution via MD simulation.

    Science.gov (United States)

    Uddin, M; Coombe, D

    2014-03-20

    Molecular dynamics simulations of gas hydrate dissociation comparing the behavior of CH4 and CO2 hydrates are presented. These simulations were based on a structurally correct theoretical gas hydrate crystal, coexisting with water. The MD system was first initialized and stabilized via a thorough energy minimization, constant volume-temperature ensemble and constant volume-energy ensemble simulations before proceeding to constant pressure-temperature simulations for targeted dissociation pressure and temperature responses. Gas bubble evolution mechanisms are demonstrated as well as key investigative properties such as system volume, density, energy, mean square displacements of the guest molecules, radial distribution functions, H2O order parameter, and statistics of hydrogen bonds. These simulations have established the essential similarities between CH4 and CO2 hydrate dissociation. The limiting behaviors at lower temperature (no dissociation) and higher temperature (complete melting and formation of a gas bubble) have been illustrated for both hydrates. Due to the shift in the known hydrate stability curves between guest molecules caused by the choice of water model as noted by other authors, the intermediate behavior (e.g., 260 K) showed distinct differences however. Also, because of the more hydrogen-bonding capability of CO2 in water, as reflected in its molecular parameters, higher solubility of dissociated CO2 in water was observed with a consequence of a smaller size of gas bubble formation. Additionally, a novel method for analyzing hydrate dissociation based on H-bond breakage has been proposed and used to quantify the dissociation behaviors of both CH4 and CO2 hydrates. Activation energies Ea values from our MD studies were obtained and evaluated against several other published laboratory and MD values. Intrinsic rate constants were estimated and upscaled. A kinetic reaction model consistent with macroscale fitted kinetic models has been proposed to

  1. 低分压CO2回收新技术捕集水泥窑气中CO2的侧线试验%Bypass experiment for capturing CO2 from cement furnace flue gas by low pressure CO2 recovery technology

    Institute of Scientific and Technical Information of China (English)

    黄汉根

    2011-01-01

    A bypass experiment facility for capturing CO2 from cement furnace flue gas is designed. A self-developed blended amine is used for CO2 capturing. The experimental results show that the CO2 volume content in the purified gas is lower than 1.41%, while the CO2 purity of the product gas is higher than 99 %. Using this technology, CO2 emission reduction can be realized. At the same time, CO2 product with high purity can be produced. This technology can be used as an effective technological support for enterprises to reduce CO2 emission.%设计了一套水泥窑气CO2捕集的侧线试验装置,利用自主研发的复合胺溶剂捕集窑气中的CO2.试验结果表明.新型复合胺溶剂能使净化气中CO2体积分数降至1.41%以下,产品气中CO2体积分数达到99%以上.采用该技术,可实现CO2减排并获得高纯度的CO2产品气,为企业的CO2减排提供技术支持.

  2. Leaf Cutter Ant (Atta cephalotes) Soil Modification and In Situ CO2 Gas Dynamics in a Neotropical Wet Forest

    Science.gov (United States)

    Fernandez Bou, A. S.; Carrasquillo Quintana, O.; Dierick, D.; Harmon, T. C.; Johnson, S.; Schwendenmann, L.; Zelikova, T. J.

    2016-12-01

    The goal of this work is to advance our understanding of soil carbon cycling in highly productive neotropical wet forests. More specifically, we are investigating the influence of leaf cutter ants (LCA) on soil CO2 gas dynamics in primary and secondary forest soils at La Selva Biological Station, Costa Rica. LCA are the dominant herbivore in tropical Americas, responsible for as much as 50% of the total herbivory. Their presence is increasing and their range is expanding because of forest fragmentation and other human impacts. We installed gas sampling wells in LCA (Atta cephalotes) nest and control sites (non-nests in the same soil and forest settings). The experimental design encompassed land cover (primary and secondary forest) and soil type (residual and alluvial). We collected gas samples monthly over an 18-month period. Several of the LCA nests were abandoned during this period. Nevertheless, we continued to sample these sites for LCA legacy effects. In several of the sites, we also installed sensors to continuously monitor soil moisture content, temperature, and CO2 levels. Within the 18-month period we conducted a 2-month field campaign to collect soil and nest vent CO2 efflux data from 3 of the nest-control pairs. Integrating the various data sets, we observed that for most of the sites nest and control soils behaved similarly during the tropical dry season. However, during the wet season gas well CO2 concentrations increased in the control sites while levels in the nests remained at dry season levels. This outcome suggests that ants modify soil gas transport properties (e.g., tortuosity). In situ time series and efflux sampling campaign data corroborated these findings. Abandoned nest CO2 levels were similar to those of the active nests, supporting the notion of a legacy effect from LCA manipulations. For this work, the period of abandonment was relatively short (several months to 1 year maximum), which appears to be insufficient for estimating the

  3. A breakthrough in flue gas cleanup, CO2 mitigation and H2S removal

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Wolf; Wasas, James; Stenger, Raymond; Howell, Evan

    2010-09-15

    SWAPSOL Corp. is developing commercial processes around a newly discovered reaction that reduces H2S below detectable levels while reacting with CO2 to form water, sulfur and carsuls, a carbon-sulfur polymer. The Stenger-Wasas Process (SWAP) stands to simplify sulfur removal technology as it consumes CO2 in an exothermic reaction. The SWAP has applications in landfill, sour, flue and Claus tail gas cleanup and may replace Claus technology. Destruction of waste hydrocarbons provides a source of H2S. The primary reactions and variants have been independently verified and the chemical kinetics determined by a third party laboratory.

  4. A breakthrough in flue gas cleanup, CO2 mitigation and H2S removal

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Wolf; Wasas, James; Stenger, Raymond; Howell, Evan

    2010-09-15

    SWAPSOL Corp. is developing commercial processes around a newly discovered reaction that reduces H2S below detectable levels while reacting with CO2 to form water, sulfur and carsuls, a carbon-sulfur polymer. The Stenger-Wasas Process (SWAP) stands to simplify sulfur removal technology as it consumes CO2 in an exothermic reaction. The SWAP has applications in landfill, sour, flue and Claus tail gas cleanup and may replace Claus technology. Destruction of waste hydrocarbons provides a source of H2S. The primary reactions and variants have been independently verified and the chemical kinetics determined by a third party laboratory.

  5. Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures

    Directory of Open Access Journals (Sweden)

    F. Falbo

    2014-12-01

    Full Text Available Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2 and with a mixture (30% CO2 and 70% N2 in dry and wet conditions at 25 ºC, 50 ºC, 60 ºC and 75 ºC and up to 600 kPa. Interesting values of single gas selectivity up to 60 ºC (between 31 and 28 for CO2/N2 and between 33 and 30 for CO2/CH4 in dry condition were obtained. The separation factor measured for the mixture was 20% lower compared to the single gas selectivity, in the whole temperature range analyzed. In saturation conditions the data showed that water influences the performance of the membranes, inducing a reduction of the permeance of all gases. Moreover, the presence of water caused a decrease of single gas selectivity and separation factor, although not so significant, highlighting the very high water resistance of hollow fiber membrane modules.

  6. Air-water gas exchange and CO2 flux in a mangrove-dominated estuary

    Science.gov (United States)

    Ho, David T.; Ferrón, Sara; Engel, Victor C.; Larsen, Laurel G.; Barr, Jordan G.

    2014-01-01

    Mangrove forests are highly productive ecosystems, but the fate of mangrove-derived carbon remains uncertain. Part of that uncertainty stems from the fact that gas transfer velocities in mangrove-surrounded waters are not well determined, leading to uncertainty in air-water CO2 fluxes. Two SF6 tracer release experiments were conducted to determine gas transfer velocities (k(600) = 8.3 ± 0.4 and 8.1 ± 0.6 cm h−1), along with simultaneous measurements of pCO2 to determine the air-water CO2 fluxes from Shark River, Florida (232.11 ± 23.69 and 171.13 ± 20.28 mmol C m−2 d−1), an estuary within the largest contiguous mangrove forest in North America. The gas transfer velocity results are consistent with turbulent kinetic energy dissipation measurements, indicating a higher rate of turbulence and gas exchange than predicted by commonly used wind speed/gas exchange parameterizations. The results have important implications for carbon fluxes in mangrove ecosystems.

  7. Predicting mixed-gas adsorption equilibria on activated carbon for precombustion CO2 capture.

    Science.gov (United States)

    García, S; Pis, J J; Rubiera, F; Pevida, C

    2013-05-21

    We present experimentally measured adsorption isotherms of CO2, H2, and N2 on a phenol-formaldehyde resin-based activated carbon, which had been previously synthesized for the separation of CO2 in a precombustion capture process. The single component adsorption isotherms were measured in a magnetic suspension balance at three different temperatures (298, 318, and 338 K) and over a large range of pressures (from 0 to 3000-4000 kPa). These values cover the temperature and pressure conditions likely to be found in a precombustion capture scenario, where CO2 needs to be separated from a CO2/H2/N2 gas stream at high pressure (~1000-1500 kPa) and with a high CO2 concentration (~20-40 vol %). Data on the pure component isotherms were correlated using the Langmuir, Sips, and dual-site Langmuir (DSL) models, i.e., a two-, three-, and four-parameter model, respectively. By using the pure component isotherm fitting parameters, adsorption equilibrium was then predicted for multicomponent gas mixtures by the extended models. The DSL model was formulated considering the energetic site-matching concept, recently addressed in the literature. Experimental gas-mixture adsorption equilibrium data were calculated from breakthrough experiments conducted in a lab-scale fixed-bed reactor and compared with the predictions from the models. Breakthrough experiments were carried out at a temperature of 318 K and five different pressures (300, 500, 1000, 1500, and 2000 kPa) where two different CO2/H2/N2 gas mixtures were used as the feed gas in the adsorption step. The DSL model was found to be the one that most accurately predicted the CO2 adsorption equilibrium in the multicomponent mixture. The results presented in this work highlight the importance of performing experimental measurements of mixture adsorption equilibria, as they are of utmost importance to discriminate between models and to correctly select the one that most closely reflects the actual process.

  8. Optimized CO2-flue gas separation model for a coal fired power plant

    Directory of Open Access Journals (Sweden)

    Udara S. P. R. Arachchige, Muhammad Mohsin, Morten C. Melaaen

    2013-01-01

    Full Text Available The detailed description of the CO2 removal process using mono-ethylamine (MEA as a solvent for coal-fired power plant is present in this paper. The rate based Electrolyte NRTL activity coefficient model was used in the Aspen Plus. The complete removal process with re-circulating solvent back to the absorber was implemented with the sequential modular method in Aspen Plus. The most significant cost related to CO2 capture is the energy requirement for re-generating solvent, i.e. re-boiler duty. Parameters’ effects on re-boiler duty were studied, resulting decreased re-boiler duty with the packing height and absorber packing diameter, absorber pressure, solvent temperature, stripper packing height and diameter. On the other hand, with the flue gas temperature, re-boiler duty is increased. The temperature profiles and CO2 loading profiles were used to check the model behavior.

  9. Tail gas treatment of sour-SEWGS CO2 product. Public version

    Energy Technology Data Exchange (ETDEWEB)

    Van Dijk, H.A.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2012-06-15

    This literature review covers the technologies suitable for the CO2-H2S separation within the context of CO2 purification of a pre-combustion captured stream intended for storage or reuse. The technologies considered cover existing industrially applied processes, emerging processes as well as processes in development. Several technologies capable of achieving the desired CO2-H2S separation were identified. Among them are liquid scrubbing processes Thiopaq and CrystaSulf producing elemental sulphur, selective oxidation to elemental sulphur such as MODOP or based on novel catalysts and sorbent-based (reactive) separations using low-, medium- or high-temperature (reactive) sorbents. SEWGS stands for Sorption Enhanced Water Gas Shift process.

  10. Optimized CO2-flue gas separation model for a coal fired power plant

    Energy Technology Data Exchange (ETDEWEB)

    Arachchige, Udara S.P.R. [Telemark University College, Porsgrunn (Norway); Mohsin, Muhammad [Telemark University College, Porsgrunn (Norway); Melaaen, Morten C. [Telemark University College, Porsgrunn (Norway); Tel-Tek, Porsgrunn (Norway)

    2013-07-01

    The detailed description of the CO2 removal process using mono-ethylamine (MEA) as a solvent for coal-fired power plant is present in this paper. The rate based Electrolyte NRTL activity coefficient model was used in the Aspen Plus. The complete removal process with re-circulating solvent back to the absorber was implemented with the sequential modular method in Aspen Plus. The most significant cost related to CO2 capture is the energy requirement for re-generating solvent, i.e. re-boiler duty. Parameters’ effects on re-boiler duty were studied, resulting decreased re-boiler duty with the packing height and absorber packing diameter, absorber pressure, solvent temperature, stripper packing height and diameter. On the other hand, with the flue gas temperature, re-boiler duty is increased. The temperature profiles and CO2 loading profiles were used to check the model behavior.

  11. Electrodes for Semiconductor Gas Sensors.

    Science.gov (United States)

    Lee, Sung Pil

    2017-03-25

    The electrodes of semiconductor gas sensors are important in characterizing sensors based on their sensitivity, selectivity, reversibility, response time, and long-term stability. The types and materials of electrodes used for semiconductor gas sensors are analyzed. In addition, the effect of interfacial zones and surface states of electrode-semiconductor interfaces on their characteristics is studied. This study describes that the gas interaction mechanism of the electrode-semiconductor interfaces should take into account the interfacial zone, surface states, image force, and tunneling effect.

  12. Greenhouse gas simulations with a coupled meteorological and transport model: the predictability of CO2

    Science.gov (United States)

    Polavarapu, Saroja M.; Neish, Michael; Tanguay, Monique; Girard, Claude; de Grandpré, Jean; Semeniuk, Kirill; Gravel, Sylvie; Ren, Shuzhan; Roche, Sébastien; Chan, Douglas; Strong, Kimberly

    2016-09-01

    A new model for greenhouse gas transport has been developed based on Environment and Climate Change Canada's operational weather and environmental prediction models. When provided with realistic posterior fluxes for CO2, the CO2 simulations compare well to NOAA's CarbonTracker fields and to near-surface continuous measurements, columns from the Total Carbon Column Observing Network (TCCON) and NOAA aircraft profiles. This coupled meteorological and tracer transport model is used to study the predictability of CO2. Predictability concerns the quantification of model forecast errors and thus of transport model errors. CO2 predictions are used to compute model-data mismatches when solving flux inversion problems and the quality of such predictions is a major concern. Here, the loss of meteorological predictability due to uncertain meteorological initial conditions is shown to impact CO2 predictability. The predictability of CO2 is shorter than that of the temperature field and increases near the surface and in the lower stratosphere. When broken down into spatial scales, CO2 predictability at the very largest scales is mainly due to surface fluxes but there is also some sensitivity to the land and ocean surface forcing of meteorological fields. The predictability due to the land and ocean surface is most evident in boreal summer when biospheric uptake produces large spatial gradients in the CO2 field. This is a newly identified source of uncertainty in CO2 predictions but it is expected to be much less significant than uncertainties in fluxes. However, it serves as an upper limit for the more important source of transport error and loss of predictability, which is due to uncertain meteorological analyses. By isolating this component of transport error, it is demonstrated that CO2 can only be defined on large spatial scales due to the presence of meteorological uncertainty. Thus, for a given model, there is a spatial scale below which fluxes cannot be inferred simply

  13. Model of gas composition and plasma properties in sealed cw CO2 lasers

    Science.gov (United States)

    Byron, Stanley R.; Apter, Henri

    1992-02-01

    A comprehensive set of gas-phase reactions is described that accounts for the observed CO2 decomposition in sealed cw CO2 lasers that are free of H2O vapor. The model includes reactions among the species CO2, CO, O, O2, and O3, the electron Boltzmann equation to determine dissociation and ionization rates, and the negative ions O-, O2-, CO3-, and CO4-, which affect the reduced field E/N through their influence on ambipolar diffusion and ion neutralization. The CO2 formation mechanism is O+O2+M→k2O3+M, k2=4.2×10-34 cm6/s at 300 K, e-+O3→k3O-+O2, k3=1×10-8 cm3/s, O-+CO→k4CO2+e-, k4=7×10-10 cm3/s. The value for k3 is about 5 times larger than expected on the basis of electron-beam and drift tube measurements in room-temperature ozone and is attributed to electronic and/or vibrational excitation of ozone.

  14. Winter greenhouse gas fluxes (CO2, CH4 and N2O from a subalpine grassland

    Directory of Open Access Journals (Sweden)

    L. Merbold

    2013-05-01

    Full Text Available Although greenhouse gas emissions during winter contribute significantly to annual balances, their quantification is still highly uncertain in snow-covered ecosystems. Here, carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O fluxes were measured at a subalpine managed grassland in Switzerland using concentration gradients within the snowpack (CO2, CH4, N2O and the eddy covariance method (CO2 during the winter 2010/2011. Our objectives were (1 to identify the temporal and spatial variation of greenhouse gases (GHGs and their drivers, and (2 to estimate the GHG budget of the site during this specific season (1 December–31 March, 121 days. Mean winter fluxes (December–March based on the gradient method were 0.77 ± 0.54 μmol m−2 s−1 for CO2 (1.19 ± 1.05 μmol m−2 s−1 measured by eddy covariance, −0.14 ± 0.09 nmol m−2 s−1 for CH4 and 0.23 ± 0.23 nmol m−2 s−1 for N2O, respectively. In comparison with the CO2 fluxes measured by eddy covariance, the gradient technique underestimated the effluxes by 50%. While CO2 and CH4 fluxes decreased with the progressing winter season, N2O fluxes did not follow a seasonal pattern. The major variables correlating with the fluxes of CO2 and CH4 were soil temperature and snow water equivalent, which is based on snow height and snow density. N2O fluxes were only explained poorly by any of the measured environmental variables. Spatial variability across the valley floor was smallest for CO2 and largest for N2O. During the winter season 2010/2011, greenhouse gas fluxes ranged between 550 ± 540 g CO2 m−2 estimated by the eddy covariance approach and 543 ± 247 g CO2 m−2, −0.4 ± 0.01 g CH4 m−2 and 0.11 ± 0.1 g N2O m−2 derived by the gradient technique. Total seasonal greenhouse gas emissions from the grassland were between 574 ± 276 and 581 ± 569 g CO2 eq. m−2, with N2O contributing 5% to the overall budget and CH4 reducing the budget by 0.1%. Cumulative budgets of CO2 were

  15. Analyses of photoinitiated H+CO 2 reactions: Gas phase single-collision conditions and CO 2HBr adducts

    Science.gov (United States)

    Wittig, C.; Engel, Y. M.; Levine, R. D.

    1988-12-01

    Analyses of data obtained under single-collision bulk conditions and from CO 2HBr complexes suggest that with complexes ≈80% of the OHproduct accrues via a mechanism wherein repulsive entrance-channel interactions enhance Br-HOCO † c.m. kinetic energy at the expense of HOCO † internal energy. Resonances are described in which H is localized between Br and OCO until the reactive window opens.

  16. The Relative Performance of NDIR-based Sensors in the Near Real-time Analysis of CO2 in Air

    Directory of Open Access Journals (Sweden)

    Ki-Hyun Kim

    2007-09-01

    Full Text Available In this study, the reliability of NDIR-based sensors was explored by evaluatingthe comparability between measurement systems in the near real-time analysis of CO2. Forthis purpose, replicate analyses were performed using sensors of two different model types(H-550 and B-530, ELT Company, Korea. Three replicate data of each sensor typecollected continuously by side-by-side analysis in three second intervals (a duration of 304hour were evaluated for the relative performance of NDIR sensors. The reproducibility ofsensors, when assessed by relative standard error (RSE % values of all sensor units,showed moderate changes with time with the overall mean of 2.33%. When CO2measurements from all NDIR sensor units were evaluated by correlation analysis, theresults showed strong comparability, regardless of the model type. The overall results ofthis study suggest that NDIR sensors are reliable enough to produce highly comparabledata at least in a relative sense.

  17. Intensified technology for microalgal CO2 fixation and conversion from flue gas%微藻固定转化烟气CO2强化技术

    Institute of Scientific and Technical Information of China (English)

    姜加伟; 程丽华; 徐新华; 张林; 陈欢林

    2014-01-01

    全球气候变暖和能源危机是21世纪影响人类生存发展的重要问题。微藻由于具有利用太阳能、固定CO2并转化为油脂等产物的能力以及环境适应性强、光合效率高、繁殖快等优势,微藻固碳技术有望成为缓解温室效应和能源危机的有效方法之一,但是该技术目前仍存在去除烟气 CO2转化油脂效率低的问题。本文分析了微藻固碳过程中碳传递转化途径,介绍了强化微藻固定与转化烟气 CO2的技术研究,包括微藻固碳与转化油脂的生物强化、微藻固定 CO2的反应器强化、微藻固定与转化 CO2技术的耦合,重点讨论了强化微藻固碳与转化的生物技术和膜技术研究现状及存在问题。最后指出微藻固碳的生物技术、膜技术及其他多技术的耦合有望进一步提升烟气CO2的高效固定与转化,是强化微藻固定转化烟气CO2的重要研究方向。%Microalgae has the strong ability to convert CO2 into cellular lipid product , better environmental adaptability , higher photosynthetic efficiency and the higher reproduction rate. Therefore,carbon dioxide fixation by microalgae has become one of the effective solutions to greenhouse effect and energy crisis. The bottle neck of this technology lies in the low efficiency of CO2 fixation and conversion into cellular lipid product. This paper introduced the process of CO2 fixation and conversion into organic carbon components of microalgae cell. The progresses on intensified fixation and conversion of CO2 from flue gas,including the stimulated CO2 fixation and conversion into lipid,the intensified CO2 fixation by membrane technology in a photobioreactor and the coupling of various technologies. The application of biotechnology and the membrane technology in microalgae field were elaborated and discussed. This paper also discussed the integration of microalgae biotechnology,membrane technology and the coupling of other technologies

  18. Porous materials as high performance adsorbents for CO2 capture, gas separation and purification

    Science.gov (United States)

    Wang, Jun

    Global warming resulted from greenhouse gases emission has received a widespread attention. Among the greenhouse gases, CO2 contributes more than 60% to global warming due to its huge emission amount. The flue gas contains about 15% CO2 with N2 as the balance. If CO2 can be separated from flue gas, the benefit is not only reducing the global warming effect, but also producing pure CO2 as a very useful industry raw material. Substantial progress is urgent to be achieved in an industrial process. Moreover, energy crisis is one of the biggest challenges for all countries due to the short life of fossil fuels, such as, petroleum will run out in 50 years and coal will run out in 150 years according to today's speed. Moreover, the severe pollution to the environment caused by burning fossil fuels requires us to explore sustainable, environment-friendly, and facile energy sources. Among several alternative energy sources, natural gas is one of the most promising alternative energy sources due to its huge productivity, abundant feed stock, and ease of generation. In order to realize a substantial adsorption process in industry, synthesis of new adsorbents or modification of existing adsorbent with improved properties has become the most critical issue. This dissertation reports systemic characterization and development of five serials of novel adsorbents with advanced adsorption properties. In chapter 2, nitrogen-doped Hypercross-linking Polymers (HCPs) have been synthesized successfully with non-carcinogenic chloromethyl methyl ether (CME) as the cross-linking agent within a single step. Texture properties, surface morphology, CO2/N2 selectivity, and adsorption heat have been presented and demonstrated properly. A comprehensive discussion on factors that affect the CO2 adsorption and CO2/N 2 separation has also been presented. It was found that high micropore proportion and N-content could effectively enhance CO2 uptake and CO2/N2 separation selectivity. In chapter 3, a

  19. Noble gas as tracers for CO2 deep input in petroleum reservoirs

    Science.gov (United States)

    Pujol, Magali; Stuart, Finlay; Gilfillan, Stuart; Montel, François; Masini, Emmanuel

    2016-04-01

    The sub-salt hydrocarbon reservoirs in the deep offshore part of the Atlantic Ocean passive margins are a new key target for frontier oil and gas exploration. Type I source rocks locally rich in TOC (Total Organic Carbon) combined with an important secondary connected porosity of carbonate reservoirs overlain by an impermeable salt layer gives rise to reservoirs with high petroleum potential. However, some target structures have been found to be mainly filled with CO2 rich fluids. δ13C of the CO2 is generally between -9 and -4 permil, compatible with a deep source (metamorphic or mantle). Understanding the origin of the CO2 and the relative timing of its input into reservoir layers in regard to the geodynamic context appears to be a key issue for CO2 risk evaluation. The inertness and ubiquity of noble gases in crustal fluids make them powerful tools to trace the origin and migration of mixed fluids (Ballentine and Burnard 2002). The isotopic signature of He, Ne and Ar and the elemental pattern (He to Xe) of reservoir fluid from pressurized bottom hole samples provide an insight into fluid source influences at each reservoir depth. Three main end-members can be mixed into reservoir fluids (e.g. Gilfillan et al., 2008): atmospheric signature due to aquifer recharge, radiogenic component from organic fluid ± metamorphic influence, and mantle input. Their relative fractionation provides insights into the nature of fluid transport (Burnard et al., 2012)and its relative migration timing. In the studied offshore passive margin reservoirs, from both sides of South Atlantic margin, a strong MORB-like magmatic CO2 influence is clear. Hence, CO2 charge must have occurred during or after lithospheric break-up. CO2 charge(s) history appears to be complex, and in some cases requires several inputs to generate the observed noble gas pattern. Combining the knowledge obtained from noble gas (origin, relative timing, number of charges) with organic geochemical and thermodynamic

  20. An approach to utilize a grid of EMF potentiometric CO 2 sensors in a ultra low power wireless sensor networ k

    OpenAIRE

    2010-01-01

    from the article: The demand for a wireless CO2 solution is ever increasing. One of the biggest problems with the majority of commercial available CO2 sensors is the high energy consumption which makes them unsuitable for battery operation. Possible candidates for CO2 sensing in a low power wireless application are very limited and show a problematic calibration process. This study focuses on one of those EMF candidates, which is a Ag4RbI5 based sensor. This EMF sensor is based on the potenti...

  1. Experimental determination of noble gas, SF6 and CO2 flow profiles through a porous sandstone

    Science.gov (United States)

    Kilgallon, Rachel; Gilfillan, Stuart; Edlmann, Katriona; McDermott, Chris

    2016-04-01

    The noble gases (He, Ne, Ar, Kr and Xe) and SF6 have recently been used as artificial and inherent tracers of CO2 flow and migration from within[1,2] and from geological reservoirs[3]. However, outstanding questions remain, particularly regarding the flow behaviour of the noble gases compared to CO2. Here we present results from specially constructed experimental equipment, which has been used to determine the factors affecting transport of noble gases relative to CO2 in a porous sandstone. The experimental setup consists of a sample loop that can be loaded with a desired gas mixture. This sample can be released as a pulse into a feeder gas stream through a flow cell. The flow cell consists of a 3.6 cm diameter core, which can be of any length. The sample is surrounded by aluminium foil and treated with epoxy resin inside stainless steel tubing. The flow cell is encased by two purpose designed dispersion end plates. Real-time analysis of the arrival peaks of the gases downstream is recorded using a Quadrupole Mass Spectrometer (QMS). For the experiments, a 0.96 m core of Fell Sandstone was selected to represent a porous media. Noble gases and SF6 pulses were flowed through a CO2 carrier gas at five different pressure gradients (10 - 50 kPa) with arrival profiles measured using the QMS. Surprisingly, peak arrival times of He were slower than the other noble gases at each pressure gradient. The differences in peak arrival times between He and other noble gases increased as pressure decreased and the curve profiles for each noble gas differ significantly. The heavier noble gases (Kr and Xe) along with SF6 show a steeper peak rise at initial appearance, but have a longer duration profile than the He curves. Interestingly, the breakthrough curve profiles for both Kr and Xe were similar to SF6 indicating that Kr and Xe could be substituted for SF6, which is a potent greenhouse gas, in tracing applications. In addition, CO2 pulses were passed through a N2 carrier gas. The

  2. Simulation and energy performance assessment of CO2 removal from crude synthetic natural gas via physical absorption process

    Institute of Scientific and Technical Information of China (English)

    Wanjun Guo; Fei Feng; Guohui Song; Jun Xiao; Laihong Shen

    2012-01-01

    The paper presents an energy performance assessment of CO2 removal for crude synthetic natural gas (SNG) upgrade by Selexol absorption process.A simplified process simulation of the Selexol process concerning power requirement and separation performance was developed.The assessment indicates that less pressure difference between crude SNG and absorption pressure favors the energy performance of CO2 removal process.When both crude SNG and absorption pressures are 20 bar,CO2 removal process has the best energy performance.The optimal specific power consumption of the CO2 removal process is 566 kJ/kgCO2.The sensitivity analysis shows that the CO2 removal efficiency would significantly influence the total power consumption of the removal process,as well as higher heating value (HHV) and CO2 content in SNG.However,the specific power consumption excluding crude SNG and SNG compressions changes little with the variance of CO2 removal efficiency.If by-product CO2 is compressed for CO2 capture,the process would turn into a CO2-sink for the atmosphere.Correspondingly,an increase of 281 kJ/kgCO2 in specific power consumption is required for compressing the separated CO2.

  3. Deep microbial life in the Altmark natural gas reservoir: baseline characterization prior CO2 injection

    Science.gov (United States)

    Morozova, Daria; Shaheed, Mina; Vieth, Andrea; Krüger, Martin; Kock, Dagmar; Würdemann, Hilke

    2010-05-01

    Within the framework of the CLEAN project (CO2 Largescale Enhanced gas recovery in the Altmark Natural gas field) technical basics with special emphasis on process monitoring are explored by injecting CO2 into a gas reservoir. Our study focuses on the investigation of the in-situ microbial community of the Rotliegend natural gas reservoir in the Altmark, located south of the city Salzwedel, Germany. In order to characterize the microbial life in the extreme habitat we aim to localize and identify microbes including their metabolism influencing the creation and dissolution of minerals. The ability of microorganisms to speed up dissolution and formation of minerals might result in changes of the local permeability and the long-term safety of CO2 storage. However, geology, structure and chemistry of the reservoir rock and the cap rock as well as interaction with saline formation water and natural gases and the injected CO2 affect the microbial community composition and activity. The reservoir located at the depth of about 3500m, is characterised by high salinity fluid and temperatures up to 127° C. It represents an extreme environment for microbial life and therefore the main focus is on hyperthermophilic, halophilic anaerobic microorganisms. In consequence of the injection of large amounts of CO2 in the course of a commercial EGR (Enhanced Gas Recovery) the environmental conditions (e.g. pH, temperature, pressure and solubility of minerals) for the autochthonous microorganisms will change. Genetic profiling of amplified 16S rRNA genes are applied for detecting structural changes in the community by using PCR- SSCP (PCR-Single-Strand-Conformation Polymorphism) and DGGE (Denaturing Gradient Gel Electrophoresis). First results of the baseline survey indicate the presence of microorganisms similar to representatives from other saline, hot, anoxic, deep environments. However, due to the hypersaline and hyperthermophilic reservoir conditions, cell numbers are low, so that

  4. Estimation of seismically detectable portion of a gas plume: CO2CRC Otway project case study

    Science.gov (United States)

    Pevzner, Roman; Caspari, Eva; Bona, Andrej; Galvin, Robert; Gurevich, Boris

    2013-04-01

    CO2CRC Otway project comprises of several experiments involving CO2/CH4 or pure CO2 gas injection into different geological formations at the Otway test site (Victoria, Australia). During the first stage of the project, which was finished in 2010, more than 64,000 t of gas were injected into the depleted gas reservoir at ~2 km depth. At the moment, preparations for the next stage of the project aiming to examine capabilities of seismic monitoring of small scale injection (up to 15,000 t) into saline formation are ongoing. Time-lapse seismic is one of the most typical methods for CO2 geosequestration monitoring. Significant experience was gained during the first stage of the project through acquisition and analysis of the 4D surface seismic and numerous time-lapse VSP surveys. In order to justify the second stage of the project and optimise parameters of the experiment, several modelling studies were conducted. In order to predict seismic signal we populate realistic geological model with elastic properties, model their changes using fluid substitution technique applied to the fluid flow simulation results and compute synthetic seismic baseline and monitor volumes. To assess detectability of the time-lapse signal caused by the injection, we assume that the time-lapse noise level will be equivalent to the level of difference between the last two Otway 3D surveys acquired in 2009 and 2010 using conventional surface technique (15,000 lbs vibroseis sources and single geophones as the receivers). In order to quantify the uncertainties in plume imaging/visualisation due to the time-lapse noise realisation we propose to use multiple noise realisations with the same F-Kx-Ky amplitude spectra as the field noise for each synthetic signal volume. Having signal detection criterion defined in the terms of signal/time- lapse noise level on a single trace we estimate visible portion of the plume as a function of this criterion. This approach also gives an opportunity to attempt to

  5. Modelling of gas diffusion limitations in Ni/YSZ electrode material in CO2 and co-electrolysis

    DEFF Research Database (Denmark)

    Duhn, Jakob Dragsbæk; Jensen, Anker Degn; Wedel, Stig;

    2016-01-01

    Carbon formation during CO2 and co-electrolysis (combined electrolysis of H2O and CO2)has been observed in recent studies, under operating conditions where carbon formation,based on the bulk gas composition, should be thermodynamically unfavorable. The carboncan principally be formed by the Boudo......Carbon formation during CO2 and co-electrolysis (combined electrolysis of H2O and CO2)has been observed in recent studies, under operating conditions where carbon formation,based on the bulk gas composition, should be thermodynamically unfavorable. The carboncan principally be formed...

  6. Deriving a sea surface climatology of CO2 fugacity in support of air–sea gas flux studies

    Directory of Open Access Journals (Sweden)

    L. M. Goddijn-Murphy

    2014-07-01

    Full Text Available Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean Carbon Dioxide (CO2 Atlas (SOCAT has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. fCO2 is highly sensitive to temperature and the measurements are only valid for the instantaneous sea surface temperature (SST that is measured concurrent with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air–sea CO2 fluxes it is therefore desirable to calculate fCO2 valid for climate quality SST. This paper presents a method for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using climate quality SST data from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° × 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010. The partial pressure of CO2 (pCO2 is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air–sea CO2 flux, and hence the presented fCO2 distributions can be used in air–sea gas flux calculations together with climatologies of other climate variables.

  7. Metal-Organic Framework Templated Synthesis of Ultrasmall Catalyst Loaded ZnO/ZnCo2O4 Hollow Spheres for Enhanced Gas Sensing Properties

    Science.gov (United States)

    Koo, Won-Tae; Choi, Seon-Jin; Jang, Ji-Soo; Kim, Il-Doo

    2017-03-01

    To achieve the rational design of nanostructures for superior gas sensors, the ultrasmall nanoparticles (NPs) loaded on ternary metal oxide (TMO) hollow spheres (HS) were synthesized by using the polystyrene (PS) sphere template and bimetallic metal-organic framework (BM-MOFs) mold. The zinc and cobalt based zeolite imidazole frameworks (BM-ZIFs) encapsulating ultrasmall Pd NPs (2-3 nm) were assembled on PS spheres at room temperature. After calcination at 450 °C, these nanoscale Pd particles were effectively infiltrated on the surface of ZnO/ZnCo2O4 HSs. In addition, the heterojunctions of Pd-ZnO, Pd-ZnCo2O4, and ZnO-ZnCo2O4 were formed on each phase. The synthesized Pd-ZnO/ZnCo2O4 HSs exhibited extremely high selectivity toward acetone gas with notable sensitivity (S = 69% to 5 ppm at 250 °C). The results demonstrate that MOF driven ultrasmall catalyst loaded TMO HSs were highly effective platform for high performance chemical gas sensors.

  8. Metal-Organic Framework Templated Synthesis of Ultrasmall Catalyst Loaded ZnO/ZnCo2O4 Hollow Spheres for Enhanced Gas Sensing Properties

    Science.gov (United States)

    Koo, Won-Tae; Choi, Seon-Jin; Jang, Ji-Soo; Kim, Il-Doo

    2017-01-01

    To achieve the rational design of nanostructures for superior gas sensors, the ultrasmall nanoparticles (NPs) loaded on ternary metal oxide (TMO) hollow spheres (HS) were synthesized by using the polystyrene (PS) sphere template and bimetallic metal-organic framework (BM-MOFs) mold. The zinc and cobalt based zeolite imidazole frameworks (BM-ZIFs) encapsulating ultrasmall Pd NPs (2–3 nm) were assembled on PS spheres at room temperature. After calcination at 450 °C, these nanoscale Pd particles were effectively infiltrated on the surface of ZnO/ZnCo2O4 HSs. In addition, the heterojunctions of Pd-ZnO, Pd-ZnCo2O4, and ZnO-ZnCo2O4 were formed on each phase. The synthesized Pd-ZnO/ZnCo2O4 HSs exhibited extremely high selectivity toward acetone gas with notable sensitivity (S = 69% to 5 ppm at 250 °C). The results demonstrate that MOF driven ultrasmall catalyst loaded TMO HSs were highly effective platform for high performance chemical gas sensors. PMID:28327599

  9. Carbon Mineralization by Aqueous Precipitation for Beneficial Use of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Devenney, Martin; Gilliam, Ryan; Seeker, Randy

    2013-08-01

    The objective of this project is to demonstrate an innovative process to mineralize CO2 from flue gas directly to reactive carbonates and maximize the value and versatility of its beneficial use products. The program scope includes the design, construction, and testing of a CO2 Conversion to Material Products (CCMP) Pilot Demonstration Plant utilizing CO2 from the flue gas of a power production facility in Moss Landing, CA. This topical report covers Subphase 2a which is the design phase of pilot demonstration subsystems. Materials of construction have been selected and proven in both lab scale and prototype testing to be acceptable for the reagent conditions of interest. The target application for the reactive carbonate material has been selected based upon small-scale feasibility studies and the design of a continuous fiber board production line has been completed. The electrochemical cell architecture and components have been selected based upon both lab scale and prototype testing. The appropriate quality control and diagnostic techniques have been developed and tested along with the required instrumentation and controls. Finally the demonstrate site infrastructure, NEPA categorical exclusion, and permitting is all ready for the construction and installation of the new units and upgrades.

  10. Optimization of an enclosed gas analyzer sampling system for measuring eddy covariance fluxes of H2O and CO2

    Science.gov (United States)

    Metzger, Stefan; Burba, George; Burns, Sean P.; Blanken, Peter D.; Li, Jiahong; Luo, Hongyan; Zulueta, Rommel C.

    2016-03-01

    Several initiatives are currently emerging to observe the exchange of energy and matter between the earth's surface and atmosphere standardized over larger space and time domains. For example, the National Ecological Observatory Network (NEON) and the Integrated Carbon Observing System (ICOS) are set to provide the ability of unbiased ecological inference across ecoclimatic zones and decades by deploying highly scalable and robust instruments and data processing. In the construction of these observatories, enclosed infrared gas analyzers are widely employed for eddy covariance applications. While these sensors represent a substantial improvement compared to their open- and closed-path predecessors, remaining high-frequency attenuation varies with site properties and gas sampling systems, and requires correction. Here, we show that components of the gas sampling system can substantially contribute to such high-frequency attenuation, but their effects can be significantly reduced by careful system design. From laboratory tests we determine the frequency at which signal attenuation reaches 50 % for individual parts of the gas sampling system. For different models of rain caps and particulate filters, this frequency falls into ranges of 2.5-16.5 Hz for CO2, 2.4-14.3 Hz for H2O, and 8.3-21.8 Hz for CO2, 1.4-19.9 Hz for H2O, respectively. A short and thin stainless steel intake tube was found to not limit frequency response, with 50 % attenuation occurring at frequencies well above 10 Hz for both H2O and CO2. From field tests we found that heating the intake tube and particulate filter continuously with 4 W was effective, and reduced the occurrence of problematic relative humidity levels (RH > 60 %) by 50 % in the infrared gas analyzer cell. No further improvement of H2O frequency response was found for heating in excess of 4 W. These laboratory and field tests were reconciled using resistor-capacitor theory, and NEON's final gas sampling system was developed on this

  11. In situ visualization study of CO 2 gas bubble behavior in DMFC anode flow fields

    Science.gov (United States)

    Yang, H.; Zhao, T. S.; Ye, Q.

    This paper reports on a visual study of the CO 2 bubble behavior in the anode flow field of an in-house fabricated transparent Direct Methanol Fuel Cell (DMFC), which consisted of a membrane electrode assembly (MEA) with an active area of 4.0 × 4.0 cm 2, two bipolar plates with a single serpentine channel, and a transparent enclosure. The study reveals that at low current densities, small discrete bubbles appeared in the anode flow field. At moderate current densities, a number of gas slugs formed, in addition to small discrete bubbles. And at high current densities, the flow field was predominated by rather long gas slugs. The experiments also indicate that the cell orientation had a significant effect on the cell performance, especially at low methanol flow rates; for the present flow field design the best cell performance could be achieved when the cell was orientated vertically. It has been shown that higher methanol solution flow rates reduced the average length and the number of gas slugs in the flow field, but led to an increased methanol crossover. In particular, the effect of methanol solution flow rates on the cell performance became more pronounced at low temperatures. The effect of temperature on the bubble behavior and the cell performance was also examined. Furthermore, for the present flow field consisting of a single serpentine channel, the channel-blocking phenomenon caused by CO 2 gas slugs was never encountered under all the test conditions in this work.

  12. Cycle development and design for CO2 capture from flue gas by vacuum swing adsorption.

    Science.gov (United States)

    Zhang, Jun; Webley, Paul A

    2008-01-15

    CO2 capture and storage is an important component in the development of clean power generation processes. One CO2 capture technology is gas-phase adsorption, specifically pressure (or vacuum) swing adsorption. The complexity of these processes makes evaluation and assessment of new adsorbents difficult and time-consuming. In this study, we have developed a simple model specifically targeted at CO2 capture by pressure swing adsorption and validated our model by comparison with data from a fully instrumented pilot-scale pressure swing adsorption process. The model captures nonisothermal effects as well as nonlinear adsorption and nitrogen coadsorption. Using the model and our apparatus, we have designed and studied a large number of cycles for CO2 capture. We demonstrate that by careful management of adsorption fronts and assembly of cycles based on understanding of the roles of individual steps, we are able to quickly assess the effect of adsorbents and process parameters on capture performance and identify optimal operating regimes and cycles. We recommend this approach in contrast to exhaustive parametric studies which tend to depend on specifics of the chosen cycle and adsorbent. We show that appropriate combinations of process steps can yield excellent process performance and demonstrate how the pressure drop, and heat loss, etc. affect process performance through their effect on adsorption fronts and profiles. Finally, cyclic temperature profiles along the adsorption column can be readily used to infer concentration profiles-this has proved to be a very useful tool in cyclic function definition. Our research reveals excellent promise for the application of pressure/vacuum swing adsorption technology in the arena of CO2 capture from flue gases.

  13. DFT study of the reactions of Mo and Mo+ with CO2 in gas phase

    Indian Academy of Sciences (India)

    Deman Han; Guoliang Dai; Hao Chen; Hua Yan; Junyong Wu; Chuanfeng Wang; Aiguo Zhong

    2011-05-01

    Density functional theory (DFT) calculations have been performed to explore the potential energy surfaces of C-O bond activation in CO2 molecule by gas-phase Mo+ cation and Mo atom, in order to better understanding the mechanism of second-row metal reacting with CO2. The minimum energy reaction path is found to involve the spin inversion in the different reaction steps. This potential energy curve-crossing dramatically affects reaction exothermic. The present results show that the reaction mechanism is insertion-elimination mechanism along the C-O bond activation branch. All the theoretical results not only support the existing conclusions inferred from early experiment, but also complement the pathway and mechanism for this reaction.

  14. Comparison of Dry Gas Seasonal Storage with CO2 Storage and Re-Use Potential

    OpenAIRE

    Killerud, Marie

    2013-01-01

    To make large-scale CO2 storage economic, many groups have proposed using CO2in EOR projects to create value for CO2 storage. However, CO2 EOR projectsgenerally require a large and variable supply of CO2 and consequently may requiretemporary storage of CO2 in geological formations. In order to store CO2 atoffshore sites as a source for CO2 EOR projects, the CO2 needs to be extractedfrom a storage site to a certain extent. Alternatively, CO2 EOR projects maybe developed alongside saline aquife...

  15. Comparison of Dry Gas Seasonal Storage with CO2 Storage and Re-Use Potential

    OpenAIRE

    Killerud, Marie

    2013-01-01

    To make large-scale CO2 storage economic, many groups have proposed using CO2in EOR projects to create value for CO2 storage. However, CO2 EOR projectsgenerally require a large and variable supply of CO2 and consequently may requiretemporary storage of CO2 in geological formations. In order to store CO2 atoffshore sites as a source for CO2 EOR projects, the CO2 needs to be extractedfrom a storage site to a certain extent. Alternatively, CO2 EOR projects maybe developed alongside saline aquife...

  16. CO2 abatement costs of greenhouse gas (GHG) mitigation by different biogas conversion pathways.

    Science.gov (United States)

    Rehl, T; Müller, J

    2013-01-15

    Biogas will be of increasing importance in the future as a factor in reducing greenhouse gas emissions cost-efficiently by the optimal use of available resources and technologies. The goal of this study was to identify the most ecological and economical use of a given resource (organic waste from residential, commercial and industry sectors) using one specific treatment technology (anaerobic digestion) but applying different energy conversion technologies. Average and marginal abatement costs were calculated based on Life Cycle Cost (LCC) and Life Cycle Assessment (LCA) methodologies. Eight new biogas systems producing electricity, heat, gas or automotive fuel were analyzed in order to identify the most cost-efficient way of reducing GHG emissions. A system using a combined heat and power station (which is connected to waste treatment and digestion operation facilities and located nearby potential residential, commercial or industrial heat users) was found to be the most cost-efficient biogas technology for reducing GHG emissions. Up to € 198 per tonne of CO(2) equivalents can be saved by replacing the "business as usual" systems based on fossil resources with ones based on biogas. Limited gas injection (desulfurized and dried biogas, without compression and upgrading) into the gas grid can also be a viable option with an abatement cost saving of € 72 per tonne of CO(2) equivalents, while a heating plant with a district heating grid or a system based on biogas results in higher abatement costs (€ 267 and € 270 per tonne CO(2) eq). Results from all systems are significantly influenced by whether average or marginal data are used as a reference. Beside that energy efficiency, the reference system that was replaced and the by-products as well as feedstock and investment costs were identified to be parameters with major impacts on abatement costs. The quantitative analysis was completed by a discussion of the role that abatement cost methodology can play in

  17. Utilization of high CO2 content formation gas for steam and electricity generation; Aprovechamiento del gas de formacion con alto contenido de CO2 para generacion de vapor y electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Villagomez, Paul; Lamino, Marcelo; Jacome, Jose; Pastor, Santiago [EcuadorTLC, Quito (Ecuador). Grupo PETROBRAS

    2008-07-01

    Ecuador TLC SA, as part of the PETROBRAS Group, respecting its mission to act safe, cost-effectiveness, social and environmental responsibility, currently operates an oil production project in the Ecuatorian Amazon, known as Block 18. In Block 18, the process of gas burning is response for launch approximately 10 MMSCF of the gas associated with 77% CO2 in the environment. For this reason it was built a centralized power generation plants (PGE), of 17.38 MW, taking advantage of the gas with 77% CO2 from boilers to burn it, using it as a source of heat in a combined cycle steam turbines, generating electricity. This project is environmentally efficient with reduced emissions of CO2 and as reducing fuel costs to zero. The results of CO2 reduction is a corporate goal of PETROBRAS and this project will contribute to reducing CO2 emissions by approximately 400,000 Ton over the life of the project.

  18. A circular dichroism sensor for Ni(2+) and Co(2+) based on L-cysteine capped cadmium sulfide quantum dots.

    Science.gov (United States)

    Tedsana, Wimonsiri; Tuntulani, Thawatchai; Ngeontae, Wittaya

    2015-03-31

    A new circular dichroism sensor for detecting Ni(2+) and Co(2+) was proposed for the first time using chiral chelating quantum dots. The detection principle was based on changing of circular dichroism signals of the chiral quantum dots when forming a chiral complex with Ni(2+) or Co(2+). L-Cysteine capped cadmium sulfide quantum dots (L-Cyst-CdS QDs) were proposed as a chiral probe. The CD spectrum of L-Cyst-CdS QDs was significantly changed in the presence of Ni(2+) and Co(2+). On the other hand, other studied cations did not alter the original CD spectrum. Moreover, when increasing the concentration of Ni(2+) or Co(2+), the intensity of the CD spectrum linearly increased as a function of concentration and could be useful for the quantitative analysis. The proposed CD sensor showed linear working concentration ranges of 10-60 μM and 4-80 μM with low detection limits of 7.33 μМ and 1.13 μM for the detection of Ni(2+) and Co(2+), respectively. Parameters possibly affected the detection sensitivity such as solution pH and incubation time were studied and optimized. The proposed sensor was applied to detect Ni(2+) and Co(2+) in real water samples, and the results agreed well with the analysis using the standard ICP-OES.

  19. Growth, pod, and seed yield, and gas exchange of hydroponically grown peanut in response to CO2 enrichment

    Science.gov (United States)

    Stanciel, K.; Mortley, D. G.; Hileman, D. R.; Loretan, P. A.; Bonsi, C. K.; Hill, W. A.

    2000-01-01

    The effects of elevated CO2 on growth, pod, and seed yield, and gas exchange of 'Georgia Red' peanut (Arachis hypogaea L.) were evaluated under controlled environmental conditions. Plants were exposed to concentrations of 400 (ambient), 800, and 1200 micromoles mol-1 CO2 in reach-in growth chambers. Foliage fresh and dry weights increased with increased CO2 up to 800 micromoles mol-1, but declined at 1200 micromoles mol-1. The number and the fresh and dry weights of pods also increased with increasing CO2 concentration. However, the yield of immature pods was not significantly influenced by increased CO2. Total seed yield increased 33% from ambient to 800 micromoles mol-1 CO2, and 4% from 800 to 1200 micromoles mol-1 CO2. Harvest index increased with increasing CO2. Branch length increased while specific leaf area decreased linearly as CO2 increased from ambient to 1200 micromoles mol-1. Net photosynthetic rate was highest among plants grown at 800 micromoles mol-1. Stomatal conductance decreased with increased CO2. Carboxylation efficiency was similar among plants grown at 400 and 800 micromoles mol-1 and decreased at 1200 micromoles mol-1 CO2. These results suggest that CO2 enrichment from 400 to 800 micromoles mol-1 had positive effects on peanut growth and yield, but above 800 micromoles mol-1 enrichment seed yield increased only marginally.

  20. The potential of renewables versus natural gas with CO2 capture and storage for power generation under CO2 constraints

    NARCIS (Netherlands)

    Van Den Broek, Machteld|info:eu-repo/dai/nl/092946895; Berghout, Niels|info:eu-repo/dai/nl/328201057; Rubin, Edward S.

    2015-01-01

    The costs of intermittent renewable energy systems (IRES) and power storage technologies are compared on a level playing field to those of natural gas combined cycle power plants with CO2 capture and storage (NGCC-CCS). To account for technological progress over time, an "experience curve

  1. The potential of renewables versus natural gas with CO2 capture and storage for power generation under CO2 constraints

    NARCIS (Netherlands)

    Van Den Broek, Machteld; Berghout, Niels; Rubin, Edward S.

    2015-01-01

    The costs of intermittent renewable energy systems (IRES) and power storage technologies are compared on a level playing field to those of natural gas combined cycle power plants with CO2 capture and storage (NGCC-CCS). To account for technological progress over time, an "experience curve

  2. The potential of renewables versus natural gas with CO2 capture and storage for power generation under CO2 constraints

    NARCIS (Netherlands)

    Van Den Broek, Machteld; Berghout, Niels; Rubin, Edward S.

    2015-01-01

    The costs of intermittent renewable energy systems (IRES) and power storage technologies are compared on a level playing field to those of natural gas combined cycle power plants with CO2 capture and storage (NGCC-CCS). To account for technological progress over time, an "experience

  3. Optimization of a gas sampling system for measuring eddy-covariance fluxes of H2O and CO2

    Science.gov (United States)

    Metzger, S.; Burba, G.; Burns, S. P.; Blanken, P. D.; Li, J.; Luo, H.; Zulueta, R. C.

    2015-10-01

    Several initiatives are currently emerging to observe the exchange of energy and matter between the earth's surface and atmosphere standardized over larger space and time domains. For example, the National Ecological Observatory Network (NEON) and the Integrated Carbon Observing System (ICOS) will provide the ability of unbiased ecological inference across eco-climatic zones and decades by deploying highly scalable and robust instruments and data processing. In the construction of these observatories, enclosed infrared gas analysers are widely employed for eddy-covariance applications. While these sensors represent a substantial improvement compared to their open- and closed-path predecessors, remaining high-frequency attenuation varies with site properties, and requires correction. Here, we show that the gas sampling system substantially contributes to high-frequency attenuation, which can be minimized by careful design. From laboratory tests we determine the frequency at which signal attenuation reaches 50 % for individual parts of the gas sampling system. For different models of rain caps and particulate filters, this frequency falls into ranges of 2.5-16.5 Hz for CO2, 2.4-14.3 Hz for H2O, and 8.3-21.8 Hz for CO2, 1.4-19.9 Hz for H2O, respectively. A short and thin stainless steel intake tube was found to not limit frequency response, with 50 % attenuation occurring at frequencies well above 10 Hz for both H2O and CO2. From field tests we found that heating the intake tube and particulate filter continuously with 4 W was effective, and reduced the occurrence of problematic relative humidity levels (RH > 60 %) by 50 % in the infrared gas analyser cell. No further improvement of H2O frequency response was found for heating in excess of 4 W. These laboratory and field tests were reconciled using resistor-capacitor theory, and NEON's final gas sampling system was developed on this basis. The design consists of the stainless steel intake tube, a pleated mesh

  4. Dissolution of cemented fractures in gas bearing shales in the context of CO2 sequestration

    Science.gov (United States)

    Kwiatkowski, Kamil; Szymczak, Piotr

    2016-04-01

    Carbon dioxide has a stronger binding than methane to the organic matter contained in the matrix of shale rocks [1]. Thus, the injection of CO2 into shale formation may enhance the production rate and total amount of produced methane, and simultaneously permanently store pumped CO2. Carbon dioxide can be injected during the initial fracking stage as CO2 based hydraulic fracturing, and/or later, as a part of enhanced gas recovery (EGR) [2]. Economic and environmental benefits makes CO2 sequestration in shales potentially very for industrial-scale operation [3]. However, the effective process requires large area of fracture-matrix interface, where CO2 and CH4 can be exchanged. Usually natural fractures, existing in shale formation, are preferentially reactivated during hydraulic fracturing, thus they considerably contribute to the flow paths in the resulting fracture system [4]. Unfortunately, very often these natural fractures are sealed by calcite [5]. Consequently the layer of calcite coating surfaces impedes exchange of gases, both CO2 and CH4, between shale matrix and fracture. In this communication we address the question whether carbonic acid, formed when CO2 is mixed with brine, is able to effectively dissolve a calcite layer present in the natural fractures. We investigate numerically fluid flow and dissolution of calcite coating in natural shale fractures, with CO2-brine mixture as a reactive fluid. Moreover, we discuss the differences between slow dissolution (driven by carbonic acid) and fast dissolution (driven by stronger hydrochloric acid) of calcite layer. We compare an impact of the flow rate and geometry of the fracture on the parameters of practical importance: available surface area, morphology of dissolution front, time scale of the dissolution, and the penetration length. We investigate whether the dissolution is sufficiently non-uniform to retain the fracture permeability, even in the absence of the proppant. The sizes of analysed fractures

  5. Pengaruh penambahan Ca(OH2 pada Proses Pirolisis terhadap Hasil Gasifikasi Batubara Bituminus dengan medium Gas CO2

    Directory of Open Access Journals (Sweden)

    Saripah Sobah

    2014-06-01

    Full Text Available Pemanfaatan batubara melalui proses gasifikasi perlu dikembangkan lebih lanjut karena proses ini dapat dijadikan alternatif untuk menggantikan peranan  gas alam sebagai sumber gas sintesis. Di samping itu, proses ini dapat mengurangi pencemaran lingkungan karena teknologi gasifikasi merupakan teknologi yang bersih dan dapat mengurangi jumlah gas CO2 yang dibuang ke lingkungan. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan Ca(OH2 pada proses pirolisis terhadap hasil gasifikasi arang batubara bituminus dengan medium gas CO2. Reaksi karbon dari arang batubara dengan gas CO2 pada proses gasifikasi merupakan reaksi endotermis dan berlangsung sangat lambat pada suhu di bawah 1000oC sehingga digunakan Ca(OH2 sebagai katalisator. Proses gasifikasi batubara dijalankan dalam reaktor fixed bed. Hasil penelitian menunjukkan bahwa gasifikasi arang batubara dengan penambahan Ca(OH2 pada proses pirolisis memberikan pengaruh terhadap komposisi gas hasil yaitu berkurangnya kadar gas CO2 dan menyebabkan berkurangnya kadar belerang pada arang hasil pirolisis dan gasifikasi. Proses ini juga dapat mengurangi kadar gas CO2 sebesar 63,17% dan untuk  gasifikasi tanpa Ca(OH2 , CO2 dapat dikurangi kadarnya sampai 35,2%.

  6. Energy Conservation and CO2 Emission Reduction Using Cogeneration Based on Gas Microturbine

    Directory of Open Access Journals (Sweden)

    Arezoo Khalili

    2013-09-01

    Full Text Available Daily increasing propagation of environmental pollutants, such as CO2 as the most prevailing greenhouse gas, has resulted in global warming and climate changes in the past decades. Therefore, essentiality of the optimum utilization of limited sources of energy which in turn leads to emission abatement in energy conversion process is being widely under consideration. Cogeneration, regarding energy conservation and efficiency enhancement, is known to be a noticeable and overriding strategy in substantiation of energy consumption management goal. This study deals with performance evaluation of a microturbine-based cogeneration plant and its effects on efficiency and environmental aspects by using a simulator code.

  7. An improved gas chromatography for rapid measurement of CO2,CH4 and N2O

    Institute of Scientific and Technical Information of China (English)

    WANG Ying-hong; WANG Yue-si; SUN Yang; XU Zhong-jun; LIU Guang-ren

    2006-01-01

    Combining improved injector, gas line and valve-driving modules, a GC equipped with FID and ECD, could simultaneously measure CH4, CO2 and N2O in an air sample within 4 min. Test results showed that the system has high sensitivity, resolution and precision; the linear response range of the system meets the requirement of in situ flux measurements. Thus, the system is suitable for monitoring fluxes of main greenhouse gases in terrestrial ecosystem since it is easy to use, efficacious, stable and reliable to collect data.

  8. CO and CO2 analysis in the diving gas of the fishermen of the Yucatan Peninsula.

    Science.gov (United States)

    Chin, Walter; Huchim, Oswaldo; Wegrzyn, Grace H; Sprau, Susan E; Salas, Silvia; Markovitz, Gerald H

    2015-01-01

    It is reported that more than 75% of 400 artisanal fisherman divers working off the Yucatan Peninsula experience decompression sickness (DCS) each year, making DCS an epidemic in this region. These divers use primitive hookah diving support systems (HDSS). Breathing air is supplied from inadequately filtered and poorly maintained gasoline-powered air compressors. We hypothesized that air supplies could be contaminated. Air contamination could produce symptoms consistent with some presentations of DCS. This could confound and falsely elevate the true incidence of DCS. A cross-sectional study was undertaken in a fishing community. Ten fishermen from a single cohort participated. Fishermen were instructed not to drain volume tanks following their last dive of the day before their diving air was sampled. Dräger carbon monoxide (CO) 5/a-P and carbon dioxide (CO2) 100/a Short-term Tubes were used to measure 1.0 liters (L) of gas through a Visi-Float flow meter at 0.2 L/minute. Average CO value was 42 ppm (8-150 ppm). Average CO2 was 663 ppm (600-800). Measurements exceeded recommended diving norms for CO of 20 ppm. CO2 exceeded one diving organization recommendation of 500 ppm. Separation of engine exhaust from compressor intake could decrease CO values in HDSS to acceptable standards thus eliminating one possible confounder from this DCS epidemic.

  9. Interfacial Tension and Contact Angle Determination in Water-sandstone Systems with Injection of Flue Gas and CO2

    NARCIS (Netherlands)

    Shojaikaveh, N.; Rudolph, E.S.J.; Rossen, W.R.; Van Hemert, P.; Wolf, K.H.A.A.

    2013-01-01

    Carbon capture and storage (CCS) has the potential for reducing CO2 emissions to the atmosphere. This option includes storage strategies such as CO2 injection into deep saline aquifers, depleted oil and gas reservoirs, and unmineable coal seams. This process is largely controlled by the interactions

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

    KAUST Repository

    Belmabkhout, Youssef

    2016-10-13

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

  11. Removal of high concentration CO2 from natural gas at elevated pressure via absorption process in packed column

    Institute of Scientific and Technical Information of China (English)

    L.S.Tan; K.K.Lau; M.A.Bustam; A.M.Shariff

    2012-01-01

    Carbon dioxide (CO2) removal is an essential step in natural gas (NG) processing to provide high quality gas stream products and minimize operational difficulties.This preliminary study aims to investigate the removal of CO2 at high concentration level from the mixture of CO2-NG gas stream at elevated pressure via absorption process.This is to explore the possibility of exploring high CO2 content natural gas reserves by treatment at offshore platform.A mixed amine solvent,Stonvent-Ⅱ,was used for the absorption of approximately 75 vol% CO2 in CO2-NG stream at a pressure of 10 barg.The initial solvent temperature was varied in order to study the impact of initial temperature on the absorption performance.Preliminary study at temperatures of 35 ℃ and 45 ℃ indicates that Stonvent-Ⅱ was able to perform almost 100% removal of CO2 under both conditions.However,the CO2 absorption effect took place faster when the initial liquid temperature was lower.This is because when the initial liquid temperature is high,the temperature increase in the packing bed caused by the reaction heat is high which impacts the efficiency of absorption negatively.

  12. Performance of a CO2 impedimetric sensor prototype for air quality monitoring.

    Science.gov (United States)

    Mandayo, Gemma García; Herrán, Jaime; Castro-Hurtado, Irene; Castaño, Enrique

    2011-01-01

    Carbon dioxide detection is a relevant issue in many fields, and this work focuses on the use of a BaTiO(3)-CuO sputtered thin film layer in a gas sensor prototype for air quality measurements. For this, a double side sensor was fabricated, with a Pt heater on one side and the sensing layer over the electrodes on the other side. The uniformity of the temperature on the sensing layer was tested and further tests to check its sensing performance were carried out. Humidity influence in the detection was found to be almost negligible within the usual range in air quality measurements and repeatability tests show satisfactory results for air quality control purposes.

  13. Monitoring off-gas O2/CO2 to predict nitrification performance in activated sludge processes.

    Science.gov (United States)

    Leu, Shao-Yuan; Libra, Judy A; Stenstrom, Michael K

    2010-06-01

    Nitrification/denitrification (NDN) processes are the most widely used technique to remove nitrogenous pollutants from municipal wastewater. The performance of nitrogen removal in the NDN process depends on the metabolism of nitrifying bacteria, and is dependent on adequate oxygen supply. Off-gas testing is a convenient and popular method for measuring oxygen transfer efficiency (OTE) under process conditions and can be performed in real-time. Since carbon dioxide is produced by carbonaceous oxidizing organism and not by nitrifiers, it should be possible to use the off-gas carbon dioxide mole fraction to estimate nitrification performance independently of the oxygen uptake rate (OUR) or OTE. This paper used off-gas data with a dynamic model to estimate nitrifying efficiency for various activated sludge process conditions. The relationship among nitrification, oxygen transfer, carbon dioxide production, and pH change was investigated. Experimental results of an online off-gas monitoring for a full-scale treatment plant were used to validate the model. The results showed measurable differences in OUR and carbon dioxide transfer rate (CTR) and the simulations successfully predicted the effluent ammonia by using the measured CO(2) and O(2) contents in off-gas as input signal. Carbon dioxide in the off-gas could be a useful technique to control aeration and to monitor nitrification rate.

  14. Gas composition and soil CO2 flux at Changbaishan intra-plate volcano, NE China

    Science.gov (United States)

    wen, H.; Yang, T. F.; Guo, Z.; Fu, C.; Zhang, M.

    2011-12-01

    Changbaishan, located on the border of China and North Korea, is one of the most active volcanoes in China. This volcano violently erupted 1000 years ago and produced massive magma and widespread volcanic ash, resulting in one of the largest explosive eruptions during the last 2000 years. Recent gas emissions and seismic events in the Tianchi area suggested potential increasing volcanic activities. If that is so, then 1 million residents living on the crater flank shall be endangered by enormous volcanic hazards, including the threat of 2 billion tons of water in the crater lake . In order to better understand current status of Changbaishan, we investigated gas geochemistry in samples from the Tianchi crater lake and surrounding areas. Bubbling gas from hot springs were collected and analyzed. The results show that CO2 is the major component gas for most samples. The maximum value of helium isotopic ratio 5.8 RA (where RA = 3He/4He in air) implies more than 60% of helium is contributed by mantle component, while carbon isotope values fall in the range of -5.8 to -2.0% (vs. PDB), indicating magmatic source signatures as well. Nitrogen dominated samples, 18Dawgo, have helium isotopic ratio 0.7 RA and carbon isotope value -11.4% implying the gas source might be associated with regional crustal components in 18Dawgo. The first-time systematic soil CO2 flux measurements indicate the flux is 22.8 g m-2 day-1 at the western flank of Changbaishan, which is at the same level as the background value in the Tatun Volcano Group (24.6 g m-2 day-1), implying that it may not be as active as TVG.

  15. Gas sensor protection device and method

    Science.gov (United States)

    Boyd, David; Magera, Craig

    2016-11-08

    A gas sensor includes a sensor housing and a sensing element located within the sensor housing. The sensing element has a distal end and defines an axis. The gas sensor also includes a sensor protection device coupled to the sensor housing and at least partially surrounding the distal end of the sensing element. The sensor protection device includes a first member coupled to the housing, the first member having a generally rectangular cross-sectional shape in a plane perpendicular to the axis. The first member includes a gas inlet and a gas outlet. The sensor protection device also includes a second member coupled to the housing.

  16. Pollution Monitoring System Using Gas Sensor based on Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    M. Udin Harun Al Rasyid

    2016-01-01

    Full Text Available Carbon monoxide (CO and carbon dioxide (CO2 gases are classified as colorless and odorless gas so we need special tools to monitor their concentration in the air. Concentration of air pollution of CO and CO2 that are high in the air will give serious effects for health status. CO is a poisonous gas that damages the circulation of oxygen in the blood when inhaled, while CO2 is one of the gases that causes global warming. In this paper, we developed an integrated pollution monitoring (IPOM system to monitor the concentration of air pollution. This research implemented three sensor nodes (end-device which each node contains CO and CO2 sensors on the gas sensors board to perform sensing from the environment. Furthermore, the data taken from the environment by the sensor will be sent to the meshlium gateway using IEEE 802.15.4 Zigbee communications and processed by the gateway in order to be sent to the computer server. The data is stored in meshlium gateway using MySQL database as a backup, and it will be synchronized to the MySQL database in the computer server. We provide services for public to access the information in database server through a desktop and website application.

  17. Are seafloor pockmarks on the Chatham Rise, New Zealand, linked to CO2 hydrates? Gas hydrate stability considerations.

    Science.gov (United States)

    Pecher, I. A.; Davy, B. W.; Rose, P. S.; Coffin, R. B.

    2015-12-01

    Vast areas of the Chatham Rise east of New Zealand are covered by seafloor pockmarks. Pockmark occurrence appears to be bathymetrically controlled with a band of smaller pockmarks covering areas between 500 and 700 m and large seafloor depressions beneath 800 m water depth. The current depth of the top of methane gas hydrate stability in the ocean is about 500 m and thus, we had proposed that pockmark formation may be linked to methane gas hydrate dissociation during sealevel lowering. However, while seismic profiles show strong indications of fluid flow, geochemical analyses of piston cores do not show any evidence for current or past methane flux. The discovery of Dawsonite, indicative of significant CO2 flux, in a recent petroleum exploration well, together with other circumstantial evidence, has led us to propose that instead of methane hydrate, CO2 hydrate may be linked to pockmark formation. We here present results from CO2 hydrate stability calculations. Assuming water temperature profiles remain unchanged, we predict the upper limit of pockmark occurrence to coincide with the top of CO2 gas hydrate stability during glacial-stage sealevel lowstands. CO2 hydrates may therefore have dissociated during sealevel lowering leading to gas escape and pockmark formation. In contrast to our previous model linking methane hydrate dissociation to pockmark formation, gas hydrates would dissociate beneath a shallow base of CO2 hydrate stability, rather than on the seafloor following upward "grazing" of the top of methane hydrate stability. Intriguingly, at the water depths of the larger seafloor depressions, the base of gas hydrate stability delineates the phase boundary between CO2 hydrates and super-saturated CO2. We caution that because of the high solubility of CO2, dissociation from hydrate to free gas or super-saturated CO2 would imply high concentrations of CO2 and speculate that pockmark formation may be linked to CO2 hydrate dissolution rather than dissociation

  18. Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

    Science.gov (United States)

    Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

    2015-12-01

    Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

  19. Fault reactivation and seismicity risk from CO2 sequestration in the Chinshui gas field, NW Taiwan

    Science.gov (United States)

    Sung, Chia-Yu; Hung, Jih-Hao

    2015-04-01

    The Chinshui gas field located in the fold-thrust belt of western Taiwan was a depleted reservoir. Recently, CO2 sequestration has been planned at shallower depths of this structure. CO2 injection into reservoir will generate high fluid pressure and trigger slip on reservoir-bounding faults. We present detailed in-situ stresses from deep wells in the Chinshui gas field and evaluated the risk of fault reactivation for underground CO2 injection. The magnitudes of vertical stress (Sv), formation pore pressure (Pf) and minimum horizontal stress (Shmin) were obtained from formation density logs, repeat formation tests, sonic logs, mud weight, and hydraulic fracturing including leak-off tests and hydraulic fracturing. The magnitude of maximum horizontal stress (SHmax) was constrained by frictional limit of critically stressed faults. Results show that vertical stress gradient is about 23.02 MPa/km (1.02 psi/ft), and minimum horizontal stress gradient is 18.05 MPa/km (0.80 psi/ft). Formation pore pressures were hydrostatic at depths 2 km, and increase with a gradient of 16.62 MPa/km (0.73 psi/ft). The ratio of fluid pressure and overburden pressure (λp) is 0.65. The upper bound of maximum horizontal stress constrained by strike-slip fault stress regime (SHmax>Sv>Shmin) and coefficient of friction (μ=0.6) is about 18.55 MPa/km (0.82 psi/ft). The orientation of maximum horizontal stresses was calculated from four-arm caliper tools through the methodology suggested by World Stress Map (WMS). The mean azimuth of preferred orientation of borehole breakouts are in ~65。N. Consequently, the maximum horizontal stress axis trends in 155。N and sub-parallel to the far-field plate-convergence direction. Geomechanical analyses of the reactivation of pre-existing faults was assessed using 3DStress and Traptester software. Under current in-situ stress, the middle block fault has higher slip tendency, but still less than frictional coefficient of 0.6 a common threshold value for

  20. Non-linear response of soil carbon gas (CO2, CH4) flux to oxygen availability

    Science.gov (United States)

    Mcnicol, G.; Silver, W. L.

    2013-12-01

    Soil oxygen (O2) concentration can impact soil carbon (C) fluxes of carbon dioxide (CO2) and methane (CH4), and is an important chemical gradient across the terrestrial-aquatic interface that drives large differences in ecosystem C storage. Few studies have established quantitative relationships between gas-phase O2 concentration and soil C fluxes in controlled settings. Though standard Michaelis-Menten enzyme kinetics would predict a highly non-linear relationship between O2 concentration and microbial consumption, existing studies have imposed coarse changes in O2 concentration that necessarily prevent detection of non-linearity. We report on the results of laboratory incubations designed to explore the short-term sensitivity of soil C emissions to a wide range of gas-phase O2 concentrations. Organic-rich soil was collected from a drained peatland and subjected to seven O2 concentration treatments ranging from 0.03 % - 20 % O2. We compared the fit of the observed C flux response to O2 concentration to linear, log-linear, and Michaelis-Menten functions using MSE and residual fits as performance metrics. We found that both CO2 and CH4 emissions were highly sensitive to O2 concentration, with emission rates increasing and decreasing, respectively, at higher O2. Net CH4 emission rates were attenuated at higher O2 concentrations most likely due to stimulation of gross CH4 consumption. A log-linear or Michaelis-Menten model better fit data than a linear model by both performance metrics, demonstrating, empirically, a non-linear relationship between O2 concentration and soil CO2 and CH4 fluxes. Our results suggest high O2 sensitivity of C-rich soils at the terrestrial-aquatic interface and show that the microbial response to soil redox chemistry must be measured over a biophysically meaningful range of conditions to derive relationships that accurately predict soil C fluxes.

  1. Hydrogen production from food wastes and gas post-treatment by CO2 adsorption.

    Science.gov (United States)

    Redondas, V; Gómez, X; García, S; Pevida, C; Rubiera, F; Morán, A; Pis, J J

    2012-01-01

    The production of H(2) by biological means, although still far from being a commercially viable proposition, offers great promise for the future. Purification of the biogas obtained may lead to the production of highly concentrated H(2) streams appropriate for industrial application. This research work evaluates the dark fermentation of food wastes and assesses the possibility of adsorbing CO(2) from the gas stream by means of a low cost biomass-based adsorbent. The reactor used was a completely stirred tank reactor run at different hydraulic retention times (HRTs) while the concentration of solids of the feeding stream was kept constant. The results obtained demonstrate that the H(2) yields from the fermentation of food wastes were affected by modifications in the hydraulic retention time (HRT) due to incomplete hydrolysis. The decrease in the duration of fermentation had a negative effect on the conversion of the substrate into soluble products. This resulted in a lower amount of soluble substrate being available for metabolisation by H(2) producing microflora leading to a reduction in specific H(2) production. Adsorption of CO(2) from a gas stream generated from the dark fermentation process was successfully carried out. The data obtained demonstrate that the column filled with biomass-derived activated carbon resulted in a high degree of hydrogen purification. Co-adsorption of H(2)S onto the activated carbon also took place, there being no evidence of H(2)S present in the bio-H(2) exiting the column. Nevertheless, the concentration of H(2)S was very low, and this co-adsorption did not affect the CO(2) capture capacity of the activated carbon.

  2. Natural gas consumption, income, urbanization, and CO2 emissions in China and India.

    Science.gov (United States)

    Solarin, Sakiru Adebola; Lean, Hooi Hooi

    2016-09-01

    The objective of this study is to examine the impact of natural gas consumption, output, and urbanization on CO2 emission in China and India for the period, 1965-2013. A cointegraton test, which provides for endogenously determined structural breaks, has been applied to examine the long-run relationship and to investigate the presence of environmental Kuznets curve (EKC) in the two countries. The presence of causal relationship between the variables is also investigated. The findings show that there is a long-run relationship in the variables and natural gas, real GDP, and urbanization have long-run positive impact on emission in both countries. There is no evidence for EKC in China and India. The findings further suggest that there is a long-run feedback relationship between the variables. The policy inferences of these findings are discussed.

  3. Vacuum UV photolysis of CO 2. Rare-gas oxide formation in matrices

    Science.gov (United States)

    Fournier, J.; Mohammed, H. H.; Deson, J.; Maillard, D.

    1982-08-01

    In this paper, we report experimental results obtained upon photolysis of CO 2 trapped at low concentrations (0.1%) in neon, argon and krypton matrices. The mixture are photolysed using a xenon resonance lamp emitting photons at 8.4 eV. Only in a neon matrix does the photolysis of CO 2 lead to O( 1D) → O( 3P) emission. Furthermore, oxygen atoms are shown to diffuse at all temperatures in a neon matrix (as detected by molecular oxygen emission), whereas in the other matrices this occurs only when the sample is warmed even though irradiation is performed at high temperature. In argon and krypton matrices, O( 1S) → O( 1D) emission is observed even though there is not enough energy to form an O( 1S) atom in a primary photodecomposition process. This suggests that O( 1D) becomes bound to argon or krypton atoms as a stable rare-gas oxide RGO excimer, which is subsequently excited and photolysed by 8.4 eV photons. These observed features are explained using a model for the interaction between oxygen ( 3P, 1D, 1S) and rare-gas atoms ( 1S) which had previously been proposed to account for the emission spectra of oxygen atoms observed during photolysis of oxygenated compounds.

  4. Ground gas monitoring: implications for hydraulic fracturing and CO2 storage.

    Science.gov (United States)

    Teasdale, Christopher J; Hall, Jean A; Martin, John P; Manning, David A C

    2014-12-02

    Understanding the exchange of carbon dioxide (CO2) and methane (CH4) between the geosphere and atmosphere is essential for the management of anthropogenic emissions. Human activities such as carbon capture and storage and hydraulic fracturing ("fracking") affect the natural system and pose risks to future global warming and to human health and safety if not engineered to a high standard. In this paper an innovative approach of expressing ground gas compositions is presented, using data derived from regulatory monitoring of boreholes in the unsaturated zone at infrequent intervals (typically 3 months) with data from a high frequency monitoring instrument deployed over periods of weeks. Similar highly variable trends are observed for time scales ranging from decades to hourly for boreholes located close to sanitary landfill sites. Additionally, high frequency monitoring data confirm the effect of meteorological controls on ground gas emissions; the maximum observed CH4 and CO2 concentrations in a borehole monitored over two weeks were 40.1% v/v and 8.5% v/v respectively, but for 70% of the monitoring period only air was present. There is a clear weakness in current point monitoring strategies that may miss emission events and this needs to be considered along with obtaining baseline data prior to starting any engineering activity.

  5. Graphene as Gas Sensors

    Institute of Scientific and Technical Information of China (English)

    Hamze Mousavi

    2011-01-01

    The triatomic and tetratomic gas molecule adsorption effects on the electrical conductivity of graphene are investigated by the tight-binding model, Green's function method, and coherent potential approximation. We find that the electrical conductivity of graphene sheet is sensitive to the adsorption of these gases.

  6. Initiation of long, free-standing z discharges by CO2 laser gas heating

    Science.gov (United States)

    Niemann, C.; Tauschwitz, A.; Penache, D.; Neff, S.; Knobloch, R.; Birkner, R.; Presura, R.; Hoffmann, D. H. H.; Yu, S. S.; Sharp, W. M.

    2002-01-01

    High current discharge channels can neutralize both current and space charge of very intense ion beams. Therefore, they are considered an interesting solution for final focus and beam transport in a heavy ion beam fusion reactor. At the Gesellschaft für Schwerionenforschung accelerator facility, 50 cm long, free-standing discharge channels were created in a 60 cm diameter metallic chamber. Discharges with currents of 45 kA in 2 to 25 mbar ammonia (NH3) gas are initiated by a CO2 laser pulse along the channel axis before the capacitor bank is triggered. Resonant absorption of the laser, tuned to the v2 vibration of the ammonia molecule, causes strong gas heating. Subsequent expansion and rarefaction of the gas prepare the conditions for a stable discharge to fulfill the requirements for ion beam transport. The influence of an electric prepulse on the high current discharge was investigated. This article describes the laser-gas interaction and the discharge initiation mechanism. We found that channels are magnetohydrodynamic stable up to currents of 45 kA, measured by fast shutter and streak imaging techniques. The rarefaction of the laser heated gas is studied by means of a one-dimensional Lagrangian fluid code (CYCLOPS) and is identified as the dominant initiation mechanism of the discharge.

  7. Nanowire-based gas sensors

    NARCIS (Netherlands)

    Chen, X.; Wong, C.K.Y.; Yuan, C.A.; Zhang, G.

    2013-01-01

    Gas sensors fabricated with nanowires as the detecting elements are powerful due to their many improved characteristics such as high surface-to-volume ratios, ultrasensitivity, higher selectivity, low power consumption, and fast response. This paper gives an overview on the recent process of the dev

  8. Highly Stable Porous Covalent Triazine-Piperazine Linked Nanoflower as a Feasible Adsorbent for Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan Kumar

    2016-02-11

    Here, we report a porous covalent triazine-piperazine linked polymer (CTPP) featuring 3D nanoflower morphology and enhanced capture/removal of CO2, CH4 from air (N2), essential to control greenhouse gas emission and natural gas upgrading. 13C solid-state NMR and FTIR analyses and CHN and X-ray photoelectron spectroscopy (XPS) elemental analyses confirmed the integration of triazine and piperazine components in the network. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) analyses revealed a relatively uniform particle size of approximately 400 to 500 nm with 3D nanoflower microstructure, which was formed by the self-assembly of interwoven and slight bent nanoflake components. The material exhibited outstanding chemical robustness under acidic and basic medium and high thermal stability up to 773 K. The CTPP possess high surface area (779 m2/g) and single-component gas adsorption study exhibited enhanced CO2 and CH4 uptake of 3.48 mmol/g, 1.09 mmol/g, respectively at 273 K, 1 bar; coupled with high sorption selectivities for CO2/N2 and CH4/N2 of 128 and 17, respectively. The enriched Lewis basicity of the CTPP favors the interaction with CO2, which results in an enhanced CO2 adsorption capacity and high CO2/N2 selectivity. The binary mixture breakthrough study for the flue gas composition at 298 K showed a high CO2/N2 selectivity of 82. CO2 heats of adsorption for the CTPP (34 kJ mol−1) were realized at the borderline between strong physisorption and weak chemisorption (QstCO2; 25−50 kJ mol−1) and low Qst value for N2 (22.09 kJ mol−1), providing the ultimate validation for the high selectivity of CO2 over N2.

  9. CO2 SELECTIVE CERAMIC MEMBRANE FOR WATER-GAS-SHIFT REACTION WITH CONCOMITANT RECOVERY OF CO2

    Energy Technology Data Exchange (ETDEWEB)

    Paul K.T. Liu

    2005-07-15

    A high temperature membrane reactor (MR) has been developed to enhance the water-gas-shift (WGS) reaction efficiency with concomitant CO{sub 2} removal for sequestration. This improved WGS-MR with CO{sub 2} recovery capability is ideally suitable for integration into the Integrated Gasification Combined-Cycle (IGCC) power generation system. Two different CO{sub 2}-affinity materials were selected in this study. The Mg-Al-CO{sub 3}-layered double hydroxide (LDH) was investigated as an adsorbent or a membrane for CO{sub 2} separation. The adsorption isotherm and intraparticle diffusivity for the LDH-based adsorbent were experimentally determined, and suitable for low temperature shift (LTS) of WGS. The LDH-based membranes were synthesized using our commercial ceramic membranes as substrate. These experimental membranes were characterized comprehensively in terms of their morphology, and CO{sub 2} permeance and selectivity to demonstrate the technical feasibility. In parallel, an alternative material-base membrane, carbonaceous membrane developed by us, was characterized, which also demonstrated enhanced CO{sub 2} selectivity at the LTS-WGS condition. With optimization on membrane defect reduction, these two types of membrane could be used commercially as CO{sub 2}-affinity membranes for the proposed application. Based upon the unique CO{sub 2} affinity of the LDHs at the LTS/WGS environment, we developed an innovative membrane reactor, Hybrid Adsorption and Membrane Reactor (HAMR), to achieve {approx}100% CO conversion, produce a high purity hydrogen product and deliver a concentrated CO{sub 2} stream for disposal. A mathematical model was developed to simulate this unique one -step process. Finally a benchtop reactor was employed to generate experimental data, which were consistent with the prediction from the HAMR mathematical model. In summary, the project objective, enhancing WGS efficiency for hydrogen production with concomitant CO{sub 2} removal for

  10. Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-01-01

    Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

  11. The effect of long-term exposure to elevated CO2 on nitrogen gas emissions from Mojave Desert soils

    Science.gov (United States)

    McCalley, Carmody K.; Strahm, Brian D.; Sparks, Kimberlee L.; Eller, Allyson S. D.; Sparks, Jed P.

    2011-09-01

    In arid regions, emissions of nitrogen (N) gases are important to long-term soil fertility and regional atmospheric chemistry, making alterations in N gas emissions an important aspect of ecosystem response to climate change. Studies at the Nevada Desert FACE Facility suggest that rising atmospheric CO2 concentrations impact ecosystems N dynamics in the Mojave Desert; our objective was to identify whether those responses translate into changes in trace N gas emissions. We measured soil fluxes of reactive N gases (NO, NOy, NH3) and N2O in plots receiving long-term fumigation with ambient and elevated (550 ppm) CO2. Reactive N gas emissions were significantly lower under elevated CO2 during high soil moisture conditions in the spring and fall. The strongest responses occurred in the islands of fertility created by the dominant shrub Larrea tridentata, where fluxes were 3-5 ng N m-2 s-1 lower in elevated CO2 plots. Changes in total N gas emissions were driven by reduced NO and NH3 emissions, with smaller changes in NOy efflux and little to no production of N2O. Lower N gas emissions under elevated CO2 reflect changes in plant and microbial demand for N, suggesting increased uptake or immobilization coupled with decreased rates of N mineralization and nitrification. This response of N gas efflux to elevated CO2 in the growing season suggests that in deserts, elevated CO2 promotes ecosystem retention of N during periods of peak biological demand. Concomitantly, exposure to elevated CO2 alters inputs of new reactive gases into the atmosphere, potentially impacting local atmospheric processes.

  12. Study of Thermal Activated CO2 Extraction Processes from Carbonate Apatites Using Gas Chromatography

    Directory of Open Access Journals (Sweden)

    V.N. Kuznetsov

    2015-10-01

    Full Text Available The study of carbonate in the structure of carbonate-containing apatites (CCA is an actual problem due to the similarity of such systems to natural apatites of mammalian bone tissue. The search of the optimal synthesis procedures was also carried out in order to obtain carbonate apatites with the highest rate of carbonate ions incorporation into the apatite structure. The analysis of carbonate-group temperature behavior in apatites of various origin helps to understand their structural and functional roles in biologically relevant apatite materials. The thermal extraction and accumulation of CO2 from biogenic and geological apatites is also of interest for the further carbon isotope analysis with accelerating mass-spectrometry. X-ray diffraction analysis, infrared spectroscopy and scanning electron microscopy as well as self-proposed gas chromatography method with thermo-programmed probe extraction were used for carbonate temperature behavior study. This new method allows determining CO2 concentration released from CCA during annealing. The defined changes in carbonate apatite structure depending on synthesis procedure were observed.

  13. Particle-in-cell modeling of streamer branching in CO2 gas

    KAUST Repository

    Levko, Dmitry

    2017-07-07

    The mechanism of streamer branching remains one of the unsolved problems of low-temperature plasma physics. The understanding of this phenomenon requires very high-fidelity models that include, for instance, the kinetic description of electrons. In this paper, we use a two-dimensional particle-in-cell Monte Carlo collisional model to study the branching of anode-directed streamers propagating through short cathode-anode gap filled with atmospheric-pressure CO2 gas. We observe three key phenomena leading to the streamer branching at the considered conditions: flattening of the streamer head, the decrease of the streamer head thickness, and the generation at the streamer head of electrons having the energy larger than 50 eV. For the conditions of our studies, the non-homogeneous distribution of such energetic electrons at the streamer head is probably the primary mechanism responsible for the streamer branching.

  14. Thermodynamic analysis of gas – steam combined cycle with carbon dioxide (CO2 emissions saving

    Directory of Open Access Journals (Sweden)

    Alka Gupta, Om Prakash, S.K. Shukla

    2011-03-01

    Full Text Available In this paper, cogeneration or combined heat and power (CHP cycle has been analyzed in order to improve the efficiency of the gas – steam combined cycle and utilization of waste heat. The efficiency of the combined cycle is improved by decreasing the compressor inlet temperature (CIT and increasing the turbine inlet temperature (TIT. It is observed that the cycle offers the advantage of making efficient use of the energy available in the fuel and in turn, eliminate some portion of pollution associated with the power generation. The study also reveals that if this cycle is being employed for cogeneration, there is a significant saving (11.60% in the amount of Carbon dioxide (CO2 emitted by the coal-fired thermal power plants.

  15. Particle-in-cell modeling of streamer branching in CO2 gas

    Science.gov (United States)

    Levko, Dmitry; Pachuilo, Michael; Raja, Laxminarayan L.

    2017-09-01

    The mechanism of streamer branching remains one of the unsolved problems of low-temperature plasma physics. The understanding of this phenomenon requires very high-fidelity models that include, for instance, the kinetic description of electrons. In this paper, we use a 2D particle-in-cell Monte Carlo collisional model to study the branching of anode-directed streamers propagating through short cathode-anode gap filled with atmospheric-pressure CO2 gas. We observe three key phenomena leading to the streamer branching at the considered conditions: flattening of the streamer head, the decrease of the streamer head thickness, and the generation at the streamer head of electrons having the energy larger than 50 eV. For the conditions of our studies, the non-homogeneous distribution of such energetic electrons at the streamer head is probably the primary mechanism responsible for the streamer branching.

  16. Design and Application of CO2 Compressor Used for Exhaust Gas Recovery in the Process of Supercritical CO2 Fluid Extraction%超临界CO2流体萃取流程中CO2尾气回收压缩机的设计及应用

    Institute of Scientific and Technical Information of China (English)

    王高平; 张和平

    2012-01-01

    某公司超临界CO2流体萃取流程中CO2尾气回收压缩机抽气时间比预期时间超出4倍以上,为解决这一问题,通过对超临界流体萃取流程和CO2的特性分析,提出了萃取流程中CO2尾气回收压缩机的设计方法及回收流程方案的选择,并对压缩机的使用与保养做了阐述.%The suction time for the CO2 compressor used for exhaust gas recovery in the process of supercritical CO2 fluid extraction is the four times above than expected time.In order to solve the problem,the design method for CO2 compressor used for exhaust gas recovery in the extraction process and the selection of recycling process scheme are pointed out based on the characteristic analysis of supercritical fluid extraction process and of CO2-And the use and maintenance of compressor are specified in this paper.

  17. Experimental determination and prediction of the compressibility factor of high CO2 content natural gas with and without water vapor

    Institute of Scientific and Technical Information of China (English)

    Xiaoqiang Bian; Zhimin Du; YongTang

    2011-01-01

    In order to study the effect of different CO2 contents on gas compressibility factor (Z-factor),the JEFRI-PVT apparatus has been used to measure the Z-factor of dry natural gas with CO2 content range from 10.74 to 70.42 mol% at the temperature range from 301.2 to 407.3 K and pressure range from 7 to 44 MPa.The results show that Z-factor decreases with increasing CO2 content in natural gas at constant temperature and increases with increasing temperature for natural gas with the same CO2 content.In addition,the Z-factor of water-saturated natural gas with high CO2 content has been measured.A comparison of the Z-factor between natural gas with and without saturated water vapor indicates that the former shows a higher Z-factor than the latter.Furthermore,Peng-Robinson,Hall-Yarborough,and Soave-Benedict-WebbRubin equations of state (EoS) are used for the calculation of Z-factor of high CO2 content natural gas with and without water vapor.The optimal binary interaction parameters (BIP) for PR EoS are presented.The measured Z-factor is compared with the calculated Z-factor based on three models,which shows that PR EoS combined with van der Waals mixing rule for gas without water and Huron-Vidal mixing rule for water-saturated gas,are in good agreement with the experimental data.

  18. Measurement of advective soil gas flux: Results of field and laboratory experiments with CO2

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Barr, Jonathan L.; Erikson, Rebecca L.; Dobeck, Laura M.; Barr, Jamie L.; Shaw, Joseph A.

    2013-10-01

    We modified our multi-channel, steady-state flow-through (SSFT), soil-CO2 flux monitoring system to include an array of inexpensive pyroelectric non-dispersive infrared detectors for full-range (0-100%) coverage of CO2 concentrations without dilution, and a larger-diameter vent tube. We then conducted field testing of this system from late July through mid-September 2010 at the Zero Emissions Research and Technology (ZERT) project site located in Bozeman, MT, and subsequently, laboratory testing at the Pacific Northwest National Laboratory (PNNL) in Richland, WA using a flux bucket filled with dry sand. In the field, an array of twenty-five SSFT and three non-steady-state (NSS) flux chambers was installed in a 10x4 m area, the long boundary of which was directly above a shallow (2-m depth) horizontal injection well located 0.5 m below the water table. Two additional chambers (one SSFT and one NSS) were installed 10 m from the well for background measurements. Volumetric soil moisture sensors were installed at each SSFT chamber to measure mean levels in the top 0.15 m of soil. A total flux of 52 kg CO2 d-1 was injected into the well for 27 d and the efflux from the soil was monitored by the chambers before, during, and for 27 d after the injection. Overall, the results were consistent with those from previous years, showing a radial efflux pattern centered on a known “hot spot”, rapid responses to changes in injection rate and wind power, evidence for movement of the CO2 plume during the injection, and nominal flux levels from the SSFT chambers that were up to 6-fold higher than those measured by adjacent NSS chambers. Soil moisture levels varied during the experiment from moderate to near saturation with the highest levels occurring consistently at the hot spot. The effects of wind on measured flux were complex and decreased as soil moisture content increased. In the laboratory, flux bucket testing with the SSFT chamber showed large measured-flux enhancement

  19. Thermo-Economic Modelling and Process Integration of CO2-Mitigation Options on Oil and Gas Platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Tock, Laurence; Breuhaus, Peter

    2014-01-01

    The offshore extraction of oil and gas is an energy-intensive process associated with large CO2 and CH4 emissions to the atmosphere and chemicals to the sea. The taxation of these emissions has encouraged the development of more energy-efficient and environmental-friendly solutions, of which three...... are assessed in this paper. The integration of steam bottoming cycles on the gas turbines or of lowtemperature power cycles on the export gas compression can result either in an additional power output, or in a greater export of natural gas. Another possibility is to implement a CO2-capture unit, which allows...... recovering CO2 that can be used for enhanced oil recovery. In this paper, a North Sea platform is considered as case study, and the site-scale retrofit integration of these three options is analysed, considering thermodynamic, economic and environmental performance indicators. The results illustrate...

  20. A ZnO Nanoparticle-Coated Long Period Fiber Grating as a Carbon Dioxide Gas Sensor

    Directory of Open Access Journals (Sweden)

    Chao-Wei Wu

    2016-10-01

    Full Text Available This study proposes a long period fiber grating (LPFG with a zinc oxide (ZnO nanoparticle layer for use as a carbon dioxide (CO2 gas sensor. Inductively coupled plasma (ICP etching, corona treatment, and electrostatic spraying were used to fabricate this ZnO nanoparticle-coated LPFG CO2 gas sensor. Repeated gas sensor tests showed that, when a 15% CO2 mixture was injected (0.2 L/min into a closed chamber into which the sensor had been placed, the CO2 gas was absorbed by the ZnO nanoparticle-coated LPFG sensor. In these tests, the transmission loss gradually decreased, and the maximum transmission loss was 2.039 dB. The concentration test results showed that as the concentration of CO2 introduced into the chamber was increased, the rate of the transmission loss change was increased in direct proportion. In addition, the sensitivity was 0.0513 dB/%. The results confirm that this low-cost ZnO nanoparticle-coated LPFG gas sensor was successfully applied to the measurement of CO2 gas. Therefore, the proposed ZnO nanoparticle-coated LPFG can be used to measure CO2 gas.

  1. Optical Breath Gas Sensor for Extravehicular Activity Application

    Science.gov (United States)

    Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Pilgrim, Jeffrey S.; Chullen, Cinda; Falconi, Eric A.; McMillin, Summer

    2013-01-01

    The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

  2. A new gas/supercritical fluid (SCF diffusivity measurement method for CO2 saturated polymer systems using a dielectric property

    Directory of Open Access Journals (Sweden)

    S. X. Yao

    2017-08-01

    Full Text Available In this research, theoretical CO2 diffusivity coefficients in amorphous polymers were calculated from dielectric constant changes during CO2 desorption. These values showed agreement with experimental diffusivity coefficients from a gravimetric method. Three amorphous polymer films made from Polystyrene (PS, Polycarbonate (PC, and Cyclic Olefin Polymer (COP resins were saturated with supercritical CO2 at 5.5 MPa and 25 °C for 24 hours in a pressure chamber. The CO2 infused films were removed from the chamber for gas desorption experiments. The capacitance of the samples were recorded with an Inductance, Capacitance and Resistance (LCR meter. These values were used to calculate the change in dielectric constants. CO2 weight percentages measured by a scale was used to calculate experimental diffusivity and solubility coefficients. It was found that the trend of dielectric constant changes was similar to that of the CO2 weight percentage changes during gas desorption. A mathematical model was built to predict the CO2 weight percentages during desorption from the measured dielectric constants. Theoretical diffusivity coefficients from this work agree well with literature data.

  3. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture - Part B: Applications

    Science.gov (United States)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

    2016-09-01

    An important advantage of solid oxide fuel cells (SOFC) as future systems for large scale power generation is the possibility of being efficiently integrated with processes for CO2 capture. Focusing on natural gas power generation, Part A of this work assessed the performances of advanced pressurised and atmospheric plant configurations (SOFC + GT and SOFC + ST, with fuel cell integration within a gas turbine or a steam turbine cycle) without CO2 separation. This Part B paper investigates such kind of power cycles when applied to CO2 capture, proposing two ultra-high efficiency plant configurations based on advanced intermediate-temperature SOFCs with internal reforming and low temperature CO2 separation process. The power plants are simulated at the 100 MW scale with a set of realistic assumptions about FC performances, main components and auxiliaries, and show the capability of exceeding 70% LHV efficiency with high CO2 capture (above 80%) and a low specific primary energy consumption for the CO2 avoided (1.1-2.4 MJ kg-1). Detailed results are presented in terms of energy and material balances, and a sensitivity analysis of plant performance is developed vs. FC voltage and fuel utilisation to investigate possible long-term improvements. Options for further improvement of the CO2 capture efficiency are also addressed.

  4. Effect of Contact Time and Gas Component on Interfacial Tension of CO2/Crude Oil System by Pendant Drop Method

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2015-01-01

    Full Text Available Pendant drop method has been used to measure the equilibrium interfacial tension and dynamic interfacial tension of CO2/crude oil system under the simulated-formation condition, in which the temperature is 355.65 K and pressure ranges from 0 MPa to 30 MPa. The test results indicated that the equilibrium interfacial tension of CO2/crude oil systems decreased with the increase of the systematic pressure. The dynamic interfacial tension of CO2/original oil, CO2/remaining oil, and CO2/produced oil systems is large at the initial contact and decreases gradually after that, and then finally it reaches dynamic balance. In addition, the higher the pressure is, the larger the magnitude of changing of CO2/crude oil interfacial tension with time will reduce. Moreover, by PVT phase experiment, gas-oil ratio, gas composition, and well fluid composition have been got, and different contents of light components in three oil samples under reservoir conditions have also been calculated. The relationship between equilibrium interfacial tensions and pressures of three different components of crude oil and CO2 system was studied, and the higher C1 is, the lower C2–C10 will be, and the equilibrium interfacial tension will get higher. Therefore, the effect of light weight fractions on interfacial tension under formation conditions was studied.

  5. Facile synthesis of triazine-triphenylamine-based microporous covalent polymer adsorbent for flue gas CO2 capture

    KAUST Repository

    Das, Swapan Kumar

    2017-07-17

    The sustainable capture and sequestration of CO2 from flue gas emission is an important and unavoidable challenge to control greenhouse gas release and climate change. In this report, we describe a triazine-triphenylamine-based microporous covalent organic polymer under mild synthetic conditions. 13C and 15N solid-state NMR and FTIR analyses confirm the linkage of the triazine and triphenylamine components in the porous polymer skeleton. The material is composed of spherical particles 1.0 to 2.0 μm in size and possesses a high surface area (1104 m2/g). The material exhibits superb chemical robustness under acidic and basic conditions and high thermal stability. Single-component gas adsorption exhibits an enhanced CO2 uptake of 3.12 mmol/g coupled with high sorption selectivity for CO2/N2 of 64 at 273 K and 1 bar, whereas the binary gas mixture breakthrough study using a model flue gas composition at 298 K shows a high CO2/N2 selectivity of 58. The enhanced performance is attributed to the high Lewis basicity of the framework, as it favors the interaction with CO2.

  6. Can Producing Oil Store Carbon? Greenhouse Gas Footprint of CO2EOR, Offshore North Sea.

    Science.gov (United States)

    Stewart, R Jamie; Haszeldine, R Stuart

    2015-05-05

    Carbon dioxide enhanced oil recovery (CO2EOR) is a proven and available technology used to produce incremental oil from depleted fields while permanently storing large tonnages of injected CO2. Although this technology has been used successfully onshore in North America and Europe, there are currently no CO2EOR projects in the United Kingdom. Here, we examine whether offshore CO2EOR can store more CO2 than onshore projects traditionally have and whether CO2 storage can offset additional emissions produced through offshore operations and incremental oil production. Using a high-level Life Cycle system approach, we find that the largest contribution to offshore emissions is from flaring or venting of reproduced CH4 and CO2. These can already be greatly reduced by regulation. If CO2 injection is continued after oil production has been optimized, then offshore CO2EOR has the potential to be carbon negative--even when emissions from refining, transport, and combustion of produced crude oil are included. The carbon intensity of oil produced can be just 0.056-0.062 tCO2e/bbl if flaring/venting is reduced by regulation. This compares against conventional Saudi oil 0.040 tCO2e/bbl or mined shale oil >0.300 tCO2e/bbl.

  7. Cost-effectiveness of greenhouse gas tax and CO2 tax

    NARCIS (Netherlands)

    Kerkhof, A.C.; Moll, H.C.; Drissen, E.; Wilting, H.C.

    2006-01-01

    Current economic instruments aimed at mitigating climate change focus on CO2 emissions, but the Kyoto Protocol refers to six greenhouse gases (CO2, CH4, N2O, HFCs, PFCs and SF6). Inclusion of non-CO2 greenhouse gases in economic instruments can increase the cost-effectiveness of achieving the Kyoto

  8. Temperature Modulation of a Catalytic Gas Sensor

    OpenAIRE

    Eike Brauns; Eva Morsbach; Sebastian Kunz; Marcus Baeumer; Walter Lang

    2014-01-01

    The use of catalytic gas sensors usually offers low selectivity, only based on their different sensitivities for various gases due to their different heats of reaction. Furthermore, the identification of the gas present is not possible, which leads to possible misinterpretation of the sensor signals. The use of micro-machined catalytic gas sensors offers great advantages regarding the response time, which allows advanced analysis of the sensor response. By using temperature modulation, additi...

  9. Electrochemical high-temperature gas sensors

    Science.gov (United States)

    Saruhan, B.; Stranzenbach, M.; Yüce, A.; Gönüllü, Y.

    2012-06-01

    Combustion produced common air pollutant, NOx associates with greenhouse effects. Its high temperature detection is essential for protection of nature. Component-integration capable high-temperature sensors enable the control of combustion products. The requirements are quantitative detection of total NOx and high selectivity at temperatures above 500°C. This study reports various approaches to detect NO and NO2 selectively under lean and humid conditions at temperatures from 300°C to 800°C. All tested electrochemical sensors were fabricated in planar design to enable componentintegration. We suggest first an impedance-metric gas sensor for total NOx-detection consisting of NiO- or NiCr2O4-SE and PYSZ-electrolyte. The electrolyte-layer is about 200μm thickness and constructed of quasi-single crystalline columns. The sensing-electrode (SE) is magnetron sputtered thin-layers of NiO or NiCr2O4. Sensor sensitivity for detection of total NOx has been measured by applying impedance analysis. The cross-sensitivity to other emission gases such as CO, CO2, CH4 and oxygen (5 vol.%) has been determined under 0-1000ppm NO. Sensor maintains its high sensitivity at temperatures up to 550°C and 600°C, depending on the sensing-electrode. NiO-SE yields better selectivity to NO in the presence of oxygen and have shorter response times comparing to NiCr2O4-SE. For higher temperature NO2-sensing capability, a resistive DC-sensor having Al-doped TiO2-sensing layers has been employed. Sensor-sensitivity towards NO2 and cross-sensitivity to CO has been determined in the presence of H2O at temperatures 600°C and 800°C. NO2 concentrations varying from 25 to 100ppm and CO concentrations from 25 to 75ppm can be detected. By nano-tubular structuring of TiO2, NO2 sensitivity of the sensor was increased.

  10. Pilot-scale multistage membrane process for the separation of CO2 from LNG-fired flue gas

    KAUST Repository

    Choi, Seung Hak

    2013-06-01

    In this study, a multistage pilot-scale membrane plant was constructed and operated for the separation of CO2 from Liquefied Natural Gas (LNG)-fired boiler flue gas of 1000 Nm3/day. The target purity and recovery of CO2 were 99 vol.% and 90%, respectively. For this purpose, asymmetric polyethersulfone (PES) hollow fibers membranes has been developed in our previous work and has evaluated the effects of operating pressure and feed concentration of CO2 on separation performance. The operating and permeation data obtained were also analyzed in relation with the numerical simulation data using countercurrent flow model. Based on these results, in this study, four-staged membrane process including dehumidification process has been designed, installed, and operated to demonstrate the feasibility of multistage membrane systems for removing CO2 from flue gases. The operation results using this plant were compared to the numerical simulation results on multistage membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery of CO2 in the permeate stream of final stage were ranged from 95-99 vol.% and 70-95%, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for CO2 recovery from flue gas. © 2013 Elsevier B.V. All rights reserved.

  11. Protective behavior of an SO2/CO2 gas mixture for molten AZ91D alloy

    Directory of Open Access Journals (Sweden)

    Liang Weizhong

    2012-08-01

    Full Text Available The protective behavior for a molten AZ91D alloy in an open melting furnace was investigated under a protective gas mixture containing 3% SO2 and 97% CO2, and the protection mechanism was discussed. Experimental results show that the gas mixture provides effective protection for AZ91D melt in the temperature range from 680 ìC to 730 ìC. The microstructure, chemical composition and phase composition of the surface film formed on the molten AZ91D alloy were analyzed using scanning electron microscopy (SEM with energy dispersive spectrometer (EDS and X-ray diffraction (XRD. The SEM results demonstrate that the surface films with an average thickness between 0.5 レm and 2 レm are dense and coherent in the protected temperature range. The EDS results reveal that the surface film mainly contains elements S, C, O, Al and Mg. The XRD results show that the surface film consists of MgO, MgS and a small amount of C phase.

  12. Optimization of a gas sampling system for measuring eddy-covariance fluxes of H2O and CO2

    Directory of Open Access Journals (Sweden)

    S. Metzger

    2015-10-01

    Full Text Available Several initiatives are currently emerging to observe the exchange of energy and matter between the earth's surface and atmosphere standardized over larger space and time domains. For example, the National Ecological Observatory Network (NEON and the Integrated Carbon Observing System (ICOS will provide the ability of unbiased ecological inference across eco-climatic zones and decades by deploying highly scalable and robust instruments and data processing. In the construction of these observatories, enclosed infrared gas analysers are widely employed for eddy-covariance applications. While these sensors represent a substantial improvement compared to their open- and closed-path predecessors, remaining high-frequency attenuation varies with site properties, and requires correction. Here, we show that the gas sampling system substantially contributes to high-frequency attenuation, which can be minimized by careful design. From laboratory tests we determine the frequency at which signal attenuation reaches 50 % for individual parts of the gas sampling system. For different models of rain caps and particulate filters, this frequency falls into ranges of 2.5–16.5 Hz for CO2, 2.4–14.3 Hz for H2O, and 8.3–21.8 Hz for CO2, 1.4–19.9 Hz for H2O, respectively. A short and thin stainless steel intake tube was found to not limit frequency response, with 50 % attenuation occurring at frequencies well above 10 Hz for both H2O and CO2. From field tests we found that heating the intake tube and particulate filter continuously with 4 W was effective, and reduced the occurrence of problematic relative humidity levels (RH > 60 % by 50 % in the infrared gas analyser cell. No further improvement of H2O frequency response was found for heating in excess of 4 W. These laboratory and field tests were reconciled using resistor-capacitor theory, and NEON's final gas sampling system was developed on this basis. The design consists of the stainless steel intake tube

  13. The Applications of Mixed Metal Oxides to Capture the CO2 and Convert to Syn-Gas

    Directory of Open Access Journals (Sweden)

    A. G. Gaikwad

    2015-01-01

    Full Text Available AbstractThe applicationsof different mixed metal oxides were explored for the capture of CO2and convert of CO2 to syn-gas. The several samples of the mixedmetal oxides were prepared by the sol gel, solid-solid fusion, precipitation,molten salt and template methods in order to investigate the performance ofmixed mtal oxides to the CO2 applications. These samples werecalcined for the 3h in air at 900 oC. The mixed metal oxides sampleswere characterized by acidity/ basicity, surface area, XRD pattern, SEM imagesand to capture CO2. The basicity and surface area of the samples of mixedmetal oxides were found to be in the range from 0.7 to 15.7 mmol g-1and 2.24 to 138.76 m2 g-1, respectively. The obtainedresults of prepared mixed metal oxides by different method were compared forthe purpose of searching the efficient materials. The temperature profiles of thecaptured CO2 by the samples of mixed metal oxides were obtained inthe range 100 to 800 oC. The captured CO2 was found to bein the range from 7.36 to 26.93 wt%. The conversions of CO2 bymethane were explored to syn-gas over the mixed metal oxides including the calciumiron lanthanum mixed metal oxides and Pd (5 wt %/Al2O3at 700 oC with the gas hourly space velocities (GHSV 6000 ml h-1g-1 of methane, 6000 ml h-1 g-1 of CO2and 24000 ml h-1 g-1 of helium.

  14. Relationship between CO2 Sensor Voltage Response and Phase Equilibrium of Solid Electrolyte Na, K-β/β"-Al2O3

    Institute of Scientific and Technical Information of China (English)

    J.H. YANG; H.N(a)fe; F. Aldinger; D.S. YAN

    2003-01-01

    A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2,CO2|Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell Ⅱ: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt.(Na,K-β/β″-Al2O3 is named by NKBA). The sensor signal is consistent with the Nernstian slope within the region ofphase equilibrium for Na, K-β/β"-Al2O3 material. The relationship between CO2 sensor voltage response and phaseequilibrium of solid electrolyte Na, K-β/β-Al2O3 is discussed in this paper.

  15. Surviving floods: leaf gas films improve O2 and CO2 exchange, root aeration, and growth of completely submerged rice

    DEFF Research Database (Denmark)

    Pedersen, Ole; Rich, Sarah Meghan; Colmer, Timothy David

    2009-01-01

    When completely submerged, the leaves of some species retain a surface gas film. Leaf gas films on submerged plants have recently been termed 'plant plastrons', analogous with the plastrons of aquatic insects. In aquatic insects, surface gas layers (i.e. plastrons) enlarge the gas–water interface...... to promote O2 uptake when under water; however, the function of leaf gas films has rarely been considered. The present study demonstrates that gas films on leaves of completely submerged rice facilitate entry of O2 from floodwaters when in darkness and CO2 entry when in light. O2 microprofiles showed...... that the improved gas exchange was not caused by differences in diffusive boundary layers adjacent to submerged leaves with or without gas films; instead, reduced resistance to gas exchange was probably due to the enlarged water–gas interface (cf. aquatic insects). When gas films were removed artificially...

  16. Dynamic simulation and optimization of an industrial-scale absorption tower for CO2 capturing from ethane gas

    Directory of Open Access Journals (Sweden)

    Babak Pouladi

    2016-11-01

    Full Text Available This article considers a process technology based on absorption for CO2 capturing of ethane gas in phase 9 and 10 of south pars in Iran using diethanolamine (DEA as absorbent solvent. This CO2 capture plant was designed to achieve 85% CO2 recovery and obtain 19 ppm the CO2 concentration in the outlet of absorber. ASPEN–HYSYS software was used for the dynamic simulation of a commercial-scale CO2 capture plant and amine Pkg equation was chosen from the fluid property package for calculating the thermodynamic properties of the process. A static approach for optimization was used to evaluate the optimum conditions. This research revealed that pressure variation does not have any considerable changes in the absorption process, while both amine inlet temperature and volumetric flow rate increment enhance the absorption tower efficiency. The effect of temperature was very significant as shown in the dynamic study plots. The optimum condition for CO2 absorption from a stream of ethane gas with molar flow rate of 2118 kg mol h−1 was obtained 75 m3  h−1 of amine at 53 °C and 24 bar. This optimized condition is acceptable from economical, safe as well as feasible point of view.

  17. A technical, economic, and environmental assessment of amine-based CO2 capture technology for power plant greenhouse gas control.

    Science.gov (United States)

    Rao, Anand B; Rubin, Edward S

    2002-10-15

    Capture and sequestration of CO2 from fossil fuel power plants is gaining widespread interest as a potential method of controlling greenhouse gas emissions. Performance and cost models of an amine (MEA)-based CO2 absorption system for postcombustion flue gas applications have been developed and integrated with an existing power plant modeling framework that includes multipollutant control technologies for other regulated emissions. The integrated model has been applied to study the feasibility and cost of carbon capture and sequestration at both new and existing coal-burning power plants. The cost of carbon avoidance was shown to depend strongly on assumptions about the reference plant design, details of the CO2 capture system design, interactions with other pollution control systems, and method of CO2 storage. The CO2 avoidance cost for retrofit systems was found to be generally higher than for new plants, mainly because of the higher energy penalty resulting from less efficient heat integration as well as site-specific difficulties typically encountered in retrofit applications. For all cases, a small reduction in CO2 capture cost was afforded by the SO2 emission trading credits generated by amine-based capture systems. Efforts are underway to model a broader suite of carbon capture and sequestration technologies for more comprehensive assessments in the context of multipollutant environmental management.

  18. Influence of shielding gas pressure on welding characteristics in CO2 laser-MIG hybrid welding process

    Institute of Scientific and Technical Information of China (English)

    Yanbin Chen; Zhenglong Lei; Liqun Li; Lin Wu

    2006-01-01

    The droplet transfer behavior and weld characteristics have been investigated under different pressures of shielding gas in CO2 laser and metal inert/active gas (laser-MIG) hybrid welding process. The experimental results indicate that the inherent droplet transfer frequency and stable welding range of conventional MIG arc are changed due to the interaction between CO2 laser beam and MIG arc in laser-MIG hybrid welding process, and the shielding gas pressure has a crucial effect on welding characteristics. When the pressure of shielding gas is low in comparison with MIG welding, the frequency of droplet transfer decreases, and thedroplet transfer becomes unstable in laser-MIG hybrid welding. So the penetration depth decreases, which shows the characteristic of unstable hybrid welding. However, when the pressure of shielding gas increases to a critical value, the hybrid welding characteristic is changed from unstable hybrid welding to stablehybrid welding, and the frequency of droplet transfer and the penetration depth increase significantly.

  19. Winter greenhouse gas emissions (CO2, CH4 and N2O from a sub-alpine grassland

    Directory of Open Access Journals (Sweden)

    F. Hagedorn

    2013-01-01

    Full Text Available Carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O fluxes were measured during the winter 2010/2011 at a~sub-alpine managed grassland in Switzerland using concentration gradients within the snowpack (CO2, CH4, N2O and the eddy covariance method (CO2. Measured snow densities were used to calculate the respective greenhouse gas (GHG fluxes. Mean winter fluxes based on the gradient method were 0.74 ± 0.53 μmol m−2 s−1 for CO2, −0.14 ± 0.09 nmol m−2 s−1 for CH4 and 0.23 ± 0.23 nmol m−2 s−1 for N2O, respectively. While CO2 and CH4 fluxes decreased with progressing winter season N2O fluxes did not follow a~seasonal pattern. Key variables driving the fluxes of CO2 and CH4 were soil surface temperatures and snow-water equivalent. N2O fluxes were only poorly explained by any of the measured factors in the soil and snow. Spatial variability across the valley floor was smallest for CO2 and largest for N2O. During the winter season 2010/2011 (November–April greenhouse gas fluxes accumulated to 631–670 g CO2 m−2, −0.04 g CH4 m−2 and 0.13 g N2O m−2. Total greenhouse gas emissions from the grassland were between 669–709 g CO2 eq. m−2, with N2O contributing 5% to the overall budget and CH4 reducing the budget by less than 1%. In comparison with the CO2 fluxes measured by eddy covariance, the gradient technique underestimated the effluxes during the main winter period by 40% but yielded similar fluxes on a seasonal basis. Cumulative budgets of CO2 were smaller than emission reported for other sub-alpine meadows in the Swiss Alps and the Rocky Mountains. It remains unclear how GHG emissions are altered by changes in climate and according snow conditions.

  20. Joint interpretation of geoelectrical and soil-gas measurements for monitoring CO2 releases at a natural analogue

    DEFF Research Database (Denmark)

    Sauer, U.; Watanabe, N.; Singh, Ashok

    2014-01-01

    The development and validation of hierarchic monitoring concepts is essential for detecting and assessing possible leakages from storage formations, especially for carbon capture and storage (CCS) applications. Joint interpretation of various techniques (such as carbon dioxide (CO2) concentration...... and flux measurements, self-potential (SP) and geoelectrical surveys) showed that the combination of geophysical methods with soil-gas analysis for mesoscale monitoring of the shallow subsurface above geologic CO2 storages can be a valuable tool for mapping and monitoring potential CO2 spread...... in the subsurface. Three measurement campaigns were undertaken - May 2011, July 2011 and April 2012 - at an analogue site in the Cheb Basin, Czech Republic, with the aim of studying CO2 leakages and their temporal and spatial behaviour. Results of geoelectrical investigations give an insight into the structural...

  1. Gravimetric dilution of calibration gas mixtures (CO2, CO, and CH4 in He balance): Toward their uncertainty estimation

    Science.gov (United States)

    Budiman, Harry; Mulyana, Muhammad Rizky; Zuas, Oman

    2017-01-01

    Uncertainty estimation for the gravimetric dilution of four calibration gas mixtures [carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4) in helium (He) Balance] have been carried out according to the International Organization for Standardization (ISO) of "Guide to the Expression of Uncertainty in Measurement". The uncertainty of the composition of gas mixtures was evaluated to measure the quality, reliability, and comparability of the prepared calibration gas mixtures. The analytical process for the uncertainty estimation is comprised of four main stages such as specification of measurand, identification, quantification of the relevant uncertainty sources, and combination of the individual uncertainty sources. In this study, important uncertainty sources including weighing, gas cylinder, component gas, certified calibration gas mixture (CCGM) added, and purity of the He balance were examined to estimate the final uncertainty of composition of diluted calibration gas mixtures. The results shows that the uncertainties of gravimetric dilution of the four calibration gas mixtures (CO2, CO, and CH4 in He Balance) were found in the range of 5.974% - 7.256% that were expressed as %relative of expanded uncertainty at 95% of confidence level (k=2). The major contribution of sources uncertainty to the final uncertainty arose from the uncertainty related to the certified calibration gas mixture (CCGM) which was the uncertainty value stated in the CCGM certificate. The verification of calibration gas mixtures composition shows that the gravimetric values of calibration gas mixtures were consistent with the results of measurement using gas chromatography flame ionization detector equipped by methanizer.

  2. Natural Gas Hydrates as CH4 Source and CO2 Sink - What do SO2 Impurities do?

    Science.gov (United States)

    Beeskow-Strauch, B.; Schicks, J. M.; Spangenberg, E.; Erzinger, J.

    2009-04-01

    The large amounts of gas hydrates stored in natural reservoirs are thought to be a promising future energy source. The recently discussed idea of methane extraction from these formations, together with the subsequent storage of CO2 in form of gas hydrates is an elegant approach to bring forward. A number of experiments have been performed on lab scale showing the replacement of CH4 by CO2 and vice versa. For instance, Graue and Kvamme (2006) demonstrated with Magnetic Resonance Images of core plug experiments the possibility of CH4 extraction by using liquid CO2. Laser Raman investigations of Schicks et al. (2007) showed, on the other hand, the ineffectiveness and slowness of the CH4 exchange reaction with gaseous CO2. After 120 hours, only 20% CH4 were exchanged for CO2. Natural methane hydrates which include often higher hydrocarbons tend to be even more stable than pure methane hydrates (Schicks et al., 2006). Contrary to lab conditions, industrial emitted CO2 contains - despite much effort to clean it - traces of impurities. For instance, CO2 emitted from the state-of-the-art Vattenfall Oxyfuel pilot plant in Schwarze Pumpe should reach a quality of >99.7% CO2 but still contains small amounts of N2, Ar, O2, SOx and NOx (pers. comm. Dr. Rolland). Here we present a microscopic and laser Raman study in a p-T range of 1 to 4 MPa and 271 to 280K focussing on CO2 hydrate formation and CH4-exchange reaction in the presence of 1% SO2. The experiments have been performed in a small-scale cryocell. The Raman spectra show that CO2 and SO2 occupy both large and small cages of the hydrate lattice. SO2 occurs strongly enriched in the hydrate clathrate, compared to its concentration in the feed gas which causes a strong acidification of the liquid phase after hydrate dissociation. Our study reveals that the hydrate formation rate from impure CO2 is similar to that of pure CO2 hydrate but that the stability of the CO2-SO2-hydrate exceeds that of pure CO2 hydrate. The improved

  3. Soil trace gas emissions (CH4 and N2O) offset the CO2 uptake in poplar short rotation coppice

    Science.gov (United States)

    Zenone, Terenzio; Zona, Donatella; Gelfand, Iya; Gielen, Bert; camino serrano, Marta; Ceulemans, Reinhart

    2015-04-01

    The need for renewable energy sources will lead to a considerable expansion in the planting of dedicated fast-growing biomass crops across Europe. Among them poplar (Populus spp) is the most widely planted as short rotation coppice (SRC) and an increase in the surface area of large-scale SRC poplar plantations might thus be expected. In this study we report the greenhouse gas fluxes (GHG) of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) measured using the eddy covariance technique in a SRC plantation for bioenergy production during the period 2010-2013. The plantation was established in April 2010 on 18.4 ha of former agricultural land with a density of 8000 plants ha-1; the above-ground biomass was harvested on February 2012 and 2014.The whole GHG balance of the four years of the study was 1.90 (± 1.37) Mg CO2eq ha-1; this indicated that soil trace gas emissions offset the CO2 uptake by the plantation. CH4 and N2O almost equally contributed to offset the CO2 uptake of -5.28 (±0.67) Mg CO2eq ha-1 with an overall emission of 3.56 (± 0.35) Mg CO2eq ha-1 of N2O and of 3.53 (± 0.85) Mg CO2eq ha-1 of CH4. N2O emissions mostly occurred during a single peak a few months after the site was converted into SRC and represented 44% of the entire N2O loss during the entire study. Accurately capturing these emission events proved to be critical for correct estimates of the GHG balance. The self-organizing map (SOM) technique graphically showed the relationship between the CO2 fluxes and the principal environmental variables but failed to explain the variability of the soil trace gas emissions. The nitrogen content in the soil and the water table depth were the two drivers that best explained the variability in N2O and CH4 respectively. This study underlines the importance of the "non-CO2 GHG" on the overall balance as well as the impact of the harvest on the CO2 uptake rate. Further long-term investigations of soil trace gas emissions should also monitor the N

  4. The dependence of Nusselt number on Reynolds number for a hot-wire sensor in supercritical CO2 flow

    Science.gov (United States)

    Vukoslavcevic, Petar; Wallace, James

    2005-11-01

    An analysis of the heat transfer mechanism around a hot-wire sensor in superctitical CO2 flow has been performed, and the dependence of the Nusselt number (Nu) on the Reynolds number (Re) has been determined. A special, closed flow loop, capable of inducing variable speed flow at different pressures and temperatures in the ranges of 0.15-2 m/s, 15-70^oC and 1-100 bar, has been used to create a supercritical CO2 flow around a hot-wire sensor operated in the constant temperature mode. The Nu and Re numbers were determined based on the known heat convected from the sensor, the flow speed and the sensor temperature and dimensions. The experiment was performed along a line of constant 80 bar pressure in the temperature range of 25-65^oC. It was found that, at a given pressure and temperature, the relation Nu=F(Re) has the classical form Nu=M+NRe^n, with the parameters M and N being functions of pressure and temperature. The dependence of these parameters on temperature was analyzed, and the most convenient reference temperature was chosen. In contrast to the operation of hot-wires in air and water, the dependence of the parameters M and N on the Prandtl number can result in nonunique solutions.

  5. Inert gas cutting of titanium sheet with pulsed mode CO 2 laser

    Science.gov (United States)

    Rao, B. Tirumala; Kaul, Rakesh; Tiwari, Pragya; Nath, A. K.

    2005-12-01

    The present work aimed at studying the dynamic behavior of melt ejection in laser cutting of 1 mm thick titanium sheet and to obtain dross-free cuts with minimum heat affected zone (HAZ). CO 2 laser cutting of titanium sheet was carried out with continuous wave (CW) and pulsed mode laser operation with different shear gases namely argon, helium and nitrogen. Laser cutting with high frequency and low-duty cycle pulse mode operation produced dross-free cuts with no noticeable HAZ. Helium, because of its high heat convection and ability to generate high shear stress, produced laser-cuts with narrow HAZ and low dross, as compared to those produced with argon as the shear gas. Microscopic features of laser cut surfaces were analyzed and correlated with dynamic mechanism involved in laser cutting process. Process parameters for laser piercing, required for the initiation of fusion cut within the sheet, were also studied. Laser piercing requires either CW or high-duty cycle (>80%) pulse mode operation.

  6. Integrated CO2 capture-fixation chemistry via interfacial ionic liquid catalyst in laminar gas/liquid flow

    Science.gov (United States)

    Vishwakarma, Niraj K.; Singh, Ajay K.; Hwang, Yoon-Ho; Ko, Dong-Hyeon; Kim, Jin-Oh; Babu, A. Giridhar; Kim, Dong-Pyo

    2017-03-01

    Simultaneous capture of carbon dioxide (CO2) and its utilization with subsequent work-up would significantly enhance the competitiveness of CO2-based sustainable chemistry over petroleum-based chemistry. Here we report an interfacial catalytic reaction platform for an integrated autonomous process of simultaneously capturing/fixing CO2 in gas-liquid laminar flow with subsequently providing a work-up step. The continuous-flow microreactor has built-in silicon nanowires (SiNWs) with immobilized ionic liquid catalysts on tips of cone-shaped nanowire bundles. Because of the superamphiphobic SiNWs, a stable gas-liquid interface maintains between liquid flow of organoamines in upper part and gas flow of CO2 in bottom part of channel. The intimate and direct contact of the binary reagents leads to enhanced mass transfer and facilitating reactions. The autonomous integrated platform produces and isolates 2-oxazolidinones and quinazolines-2,4(1H,3H)-diones with 81-97% yields under mild conditions. The platform would enable direct CO2 utilization to produce high-valued specialty chemicals from flue gases without pre-separation and work-up steps.

  7. Hydroquinone and Quinone-Grafted Porous Carbons for Highly Selective CO2 Capture from Flue Gases and Natural Gas Upgrading.

    Science.gov (United States)

    Wang, Jun; Krishna, Rajamani; Yang, Jiangfeng; Deng, Shuguang

    2015-08-04

    Hydroquinone and quinone functional groups were grafted onto a hierarchical porous carbon framework via the Friedel-Crafts reaction to develop more efficient adsorbents for the selective capture and removal of carbon dioxide from flue gases and natural gas. The oxygen-doped porous carbons were characterized with scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. CO2, CH4, and N2 adsorption isotherms were measured and correlated with the Langmuir model. An ideal adsorbed solution theory (IAST) selectivity for the CO2/N2 separation of 26.5 (298 K, 1 atm) was obtained on the hydroquinone-grafted carbon, which is 58.7% higher than that of the pristine porous carbon, and a CO2/CH4 selectivity value of 4.6 (298 K, 1 atm) was obtained on the quinone-grafted carbon (OAC-2), which represents a 28.4% improvement over the pristine porous carbon. The highest CO2 adsorption capacity on the oxygen-doped carbon adsorbents is 3.46 mmol g(-1) at 298 K and 1 atm. In addition, transient breakthrough simulations for CO2/CH4/N2 mixture separation were conducted to demonstrate the good separation performance of the oxygen-doped carbons in fixed bed adsorbers. Combining excellent adsorption separation properties and low heats of adsorption, the oxygen-doped carbons developed in this work appear to be very promising for flue gas treatment and natural gas upgrading.

  8. Remote-Raman and Micro-Raman Studies of Solid CO2, CH4, Gas Hydrates and Ice

    Science.gov (United States)

    Sharma, S. K.; Misra, A. K.; Lucey, P. G.; Exarhos, G. J.; Windisch, C. F., Jr.

    2004-01-01

    It is well known that on Mars CO2 is the principal constituent of the thin atmosphere and on a seasonal basis CO2 snow and frost coats the polar caps. Also over 25% of the Martian atmosphere freezes out and sublimes again each year. The Mars Odyssey Emission Imaging system (THEMIS) has discovered water ice exposed near the edge of Mars southern perennials cap. In recent years, it has been suggested that in Martian subsurface CO2 may exist as gas hydrate (8CO2 + 44 H2O) with melting temperature of 10C. Since the crust of Mars has been stable for enough time there is also a possibility that methane formed by magmatic processes and/or as a byproduct of anaerobic deep biosphere activity to have raised toward the planet s surface. This methane would have been captured and stored as methane hydrate, which concentrates methane and water. Determination of abundance and distribution of these ices on the surface and in the near surface are of fundamental importance for understanding Martian atmosphere, and for future exploration of Mars. In this work, we have evaluated feasibility of using remote Raman and micro-Raman spectroscopy as potential nondestructive and non-contact techniques for detecting solid CO2, CH4 gas, and gas hydrates as well as water-ice on planetary surfaces.

  9. NDIR Gas Sensor for Spatial Monitoring of Carbon Dioxide Concentrations in Naturally Ventilated Livestock Buildings

    Directory of Open Access Journals (Sweden)

    Luciano B. Mendes

    2015-05-01

    Full Text Available The tracer gas ratio method, using CO2 as natural tracer, has been suggested as a pragmatic option to measure emissions from naturally ventilated (NV barns without the need to directly estimate the ventilation rate. The aim of this research was to assess the performance of a low-cost Non-Dispersive Infra-Red (NDIR sensor for intensive spatial field monitoring of CO2 concentrations in a NV dairy cow house. This was achieved by comparing NDIR sensors with two commonly applied methods, a Photo-Acoustic Spectroscope (PAS Gas Monitor and an Open-Path laser (OP-laser. First, calibrations for the NDIR sensors were obtained in the laboratory. Then, the NDIR sensors were placed in a dairy cow barn for comparison with the PAS and OP-laser methods. The main conclusions were: (a in order to represent the overall barn CO2 concentration of the dairy cow barn, the number of NDIR sensors to be accounted for average concentration calculation was dependent on barn length and on barn area occupation; and (b the NDIR CO2 sensors are suitable for multi-point monitoring of CO2 concentrations in NV livestock barns, being a feasible alternative for the PAS and the OP-laser methods to monitor single-point or averaged spatial CO2 concentrations in livestock barns.

  10. Gas sensor with attenuated drift characteristic

    Science.gov (United States)

    Chen, Ing-Shin [Danbury, CT; Chen, Philip S. H. [Bethel, CT; Neuner, Jeffrey W [Bethel, CT; Welch, James [Fairfield, CT; Hendrix, Bryan [Danbury, CT; Dimeo, Jr., Frank [Danbury, CT

    2008-05-13

    A sensor with an attenuated drift characteristic, including a layer structure in which a sensing layer has a layer of diffusional barrier material on at least one of its faces. The sensor may for example be constituted as a hydrogen gas sensor including a palladium/yttrium layer structure formed on a micro-hotplate base, with a chromium barrier layer between the yttrium layer and the micro-hotplate, and with a tantalum barrier layer between the yttrium layer and an overlying palladium protective layer. The gas sensor is useful for detection of a target gas in environments susceptible to generation or incursion of such gas, and achieves substantial (e.g., >90%) reduction of signal drift from the gas sensor in extended operation, relative to a corresponding gas sensor lacking the diffusional barrier structure of the invention

  11. Underwater photosynthesis and respiration in leaves of submerged wetland plants: gas films improve CO2 and O2 exchange

    DEFF Research Database (Denmark)

    Colmer, Timothy David; Pedersen, Ole

    2007-01-01

    Many wetland plants have gas films on submerged leaf surfaces. We tested the hypotheses that leaf gas films enhance CO(2) uptake for net photosynthesis (P(N)) during light periods, and enhance O(2) uptake for respiration during dark periods. Leaves of four wetland species that form gas films......, and two species that do not, were used. Gas films were also experimentally removed by brushing with 0.05% (v/v) Triton X. Net O(2) production in light, or O(2) consumption in darkness, was measured at various CO(2) and O(2) concentrations. When gas films were removed, O(2) uptake in darkness was already...... diffusion-limited at 20.6 kPa (critical O(2) pressure for respiration, COP(R)>/= 284 mmol O(2) m(-3)), whereas for some leaves with gas films, O(2) uptake declined only at approx. 4 kPa (COP(R) 54 mmol O(2) m(-3)). Gas films also improved CO(2) uptake so that, during light periods, underwater P...

  12. Demonstration of CO2 capture for flue gas of a glass factory

    NARCIS (Netherlands)

    Linders, M.J.G.; Huizinga, A.; Goetheer, E.L.V.

    2012-01-01

    In the project "Connecting CO2 the next step - Carbon Capture and Use", two pilot demonstrations with a post-combustion CO2 capture setup of TNO were carried out at Ardagh Glass (Moerdijk) and Zeeland Refinery (Vlissingen). This article describes the demonstration at Ardagh, but the demonstration at

  13. Demonstration of CO2 capture for flue gas of a glass factory

    NARCIS (Netherlands)

    Linders, M.J.G.; Huizinga, A.; Goetheer, E.L.V.

    2012-01-01

    In the project "Connecting CO2 the next step - Carbon Capture and Use", two pilot demonstrations with a post-combustion CO2 capture setup of TNO were carried out at Ardagh Glass (Moerdijk) and Zeeland Refinery (Vlissingen). This article describes the demonstration at Ardagh, but the demonstration at

  14. Core Ion Structures and Solvation Effects in Gas Phase [Sn(CO_{2})_{n}]^{-} Clusters

    Science.gov (United States)

    Thompson, Michael C.; Weber, J. Mathias

    2017-06-01

    We report infrared photodissociation spectra of [Sn(CO_{2})_{n}] (n=2-6) clusters. We explore core ion geometries through quantum chemical calculations and assign our experimental spectra through comparison with calculated vibrational frequencies. We discuss our results in the context of heterogeneous catalytic reduction of CO_{2}, and compare our results with previous work on other post-transition metal species.

  15. Failure Mode and Effects Analysis of CO2 Gas Shield Welding%CO2气保焊的故障模式与影响分析

    Institute of Scientific and Technical Information of China (English)

    王余海

    2012-01-01

    Welding is a main operating process in the manufacturing of pressure vessels for commercial air- conditions. During processing, CO2 gas shield welding is mainly used, especially for fabrication of evaporators and condensers. In the actual production process, leakage faults caused by welding seriously affect the quality of prod- ucts, so it needs to optimize the welding parameters by experimental design method. However, there are. many fac- tors that affect the welds quality, so it is necessary to analyze the failure modes by FMEA before parameters de- sign to make the factors selection more accurate and effective, and pick out the key factors.%焊接是商用空调设备压力容器制造过程中的主要操作工序。CO2气体保护焊主要在蒸发器、冷凝器的装配过程中被使用。在实际生产过程中,焊接造成的故障泄漏严重影响产品质量,需要使用试验设计方法对焊接参数进行优化.但影响焊缝质量的因素众多,在进行参数设计之前,为使因素选择更准确、有效,使用FMEA(failure mode effects analysis)方法对气保焊故障模式进行分析,从中选择出关键因素。

  16. Metal-Assisted Laser-Induced Gas Plasma for the Direct Analysis of Powder Using Pulse CO2 Laser

    Science.gov (United States)

    Khumaeni, A.; Lie, Z. S.; Kurniawan, K. H.; Kagawa, K.

    2017-01-01

    Analysis of powder samples available in small quantities has been carried out using metal-assisted gas plasma by utilizing a transversely excited atmospheric (TEA) CO2 laser. The powder was homogeneously mixed with Si grease, and the mixed powder was painted on a metal subtarget. When a TEA CO2 laser was directly focused on the metal subtarget at atmospheric pressure of He gas, a high-temperature He gas plasma was induced. It is assumed that the powder particles were vaporized to be effectively atomized and excited in the gas plasma region. This method has been employed in the rapid analyses of elements in organic and inorganic powder samples present in small quantities. Detection of trace elements of Cr and Pb has been successfully made by using the supplement powder and loam soil, respectively. The detection limits of Pb in loam soil were approximately 20 mg/kg.

  17. 低气速条件下CO2在牛顿及非牛顿流体中气含率%Gas holdup of CO2 in Newtonian and non-Newtonian fluid at low gas velocity

    Institute of Scientific and Technical Information of China (English)

    李少白; 马友光; 付涛涛; 朱春英

    2012-01-01

    实验测定了低气速下CO2气泡群在牛顿流体、剪切变稀流体及黏弹性流体中的气含率.讨论了流体的流变性、质量分数及表观气速对气含率的影响.结果表明:在3种不同性质的流体中,气含率均随表观气速的增大而增大.同时发现流体性质对气含率具有不同的影响:对于牛顿流体,表观气速较低时,质量分数对气含率影响可忽略;对于非牛顿流体,气含率随着流动指数n的减小而减小,即剪切变稀效应对气含率有负作用,而黏弹性对气含率的影响可忽略.气含率是气液传质过程设计中最重要的参数,因此研究结果为进一步研究CO2气泡群在非牛顿流体中的传质奠定了一定基础.%The gas holdups of CO2 bubble swarm at low superficial gas velocity in Newtonian fluid, shear thinned fluid and viscoelastic fl uid were measured. The influences of rheological property, mass fraction and superficial gas velocity on the gas holdup were investigated. The results show that the gas holdups in three fluids all increase with the increase of superficial gas velocity, and different fluid has different effects on the gas holdup. The effect of mass fraction on the gas holdup in Newtonian fluid at low superficial gas velocity is negligible. For non-Newtonian fluid, the gas holdup decreases with the decrease of flow index n, that is, shear thinning effect has negative impact on the gas holdup, and the influence of viscoelasticity on the gas holdup is negligible. The gas holdup is the most important parameter for the gas-liquid mass transfer process design, and it provides a solid foundation for the research on mass transfer of CO2 bubble swarm in non-Newtonian fluid.

  18. Abundances of isotopologues and calibration of CO2 greenhouse gas measurements

    Science.gov (United States)

    Tans, Pieter P.; Crotwell, Andrew M.; Thoning, Kirk W.

    2017-07-01

    We have developed a method to calculate the fractional distribution of CO2 across all of its component isotopologues based on measured δ13C and δ18O values. The fractional distribution can be used with known total CO2 to calculate the amount of substance fraction (mole fraction) of each component isotopologue in air individually. The technique is applicable to any molecule where isotopologue-specific values are desired. We used it with a new CO2 calibration system to account for isotopic differences among the primary CO2 standards that define the WMO X2007 CO2-in-air calibration scale and between the primary standards and standards in subsequent levels of the calibration hierarchy. The new calibration system uses multiple laser spectroscopic techniques to measure mole fractions of the three major CO2 isotopologues (16O12C16O, 16O13C16O, and 16O12C18O) individually. The three measured values are then combined into total CO2 (accounting for the rare unmeasured isotopologues), δ13C, and δ18O values. The new calibration system significantly improves our ability to transfer the WMO CO2 calibration scale with low uncertainty through our role as the World Meteorological Organization Global Atmosphere Watch Central Calibration Laboratory for CO2. Our current estimates for reproducibility of the new calibration system are ±0.01 µmol mol-1 CO2, ±0.2 ‰ δ13C, and ±0.2 ‰ δ18O, all at 68 % confidence interval (CI).

  19. Abundances of isotopologues and calibration of CO2 greenhouse gas measurements

    Directory of Open Access Journals (Sweden)

    P. P. Tans

    2017-07-01

    Full Text Available We have developed a method to calculate the fractional distribution of CO2 across all of its component isotopologues based on measured δ13C and δ18O values. The fractional distribution can be used with known total CO2 to calculate the amount of substance fraction (mole fraction of each component isotopologue in air individually. The technique is applicable to any molecule where isotopologue-specific values are desired. We used it with a new CO2 calibration system to account for isotopic differences among the primary CO2 standards that define the WMO X2007 CO2-in-air calibration scale and between the primary standards and standards in subsequent levels of the calibration hierarchy. The new calibration system uses multiple laser spectroscopic techniques to measure mole fractions of the three major CO2 isotopologues (16O12C16O, 16O13C16O, and 16O12C18O individually. The three measured values are then combined into total CO2 (accounting for the rare unmeasured isotopologues, δ13C, and δ18O values. The new calibration system significantly improves our ability to transfer the WMO CO2 calibration scale with low uncertainty through our role as the World Meteorological Organization Global Atmosphere Watch Central Calibration Laboratory for CO2. Our current estimates for reproducibility of the new calibration system are ±0.01 µmol mol−1 CO2, ±0.2 ‰ δ13C, and ±0.2 ‰ δ18O, all at 68 % confidence interval (CI.

  20. Atomic layer deposition of Ru from CpRu(CO)(2)Et using O-2 gas and O-2 plasma

    NARCIS (Netherlands)

    Leick, N.; Verkuijlen, R. O. F.; Lamagna, L.; Langereis, E.; Rushworth, S.; Roozeboom, F.; M. C. M. van de Sanden,; Kessels, W. M. M.

    2011-01-01

    The metalorganic precursor cyclopentadienylethyl(dicarbonyl)ruthenium (CpRu(CO)(2)Et) was used to develop an atomic layer deposition (ALD) process for ruthenium. O-2 gas and O-2 plasma were employed as reactants. For both processes, thermal and plasma-assisted ALD, a relatively high growth-per-cycle

  1. Energy Efficient Solvents for CO2 Absorption from Flue Gas: Vapor Liquid Equilibrium and Pilot Plant Study

    NARCIS (Netherlands)

    Singh, Prachi; van Swaaij, Willibrordus Petrus Maria; Brilman, Derk Willem Frederik

    2013-01-01

    From solvent screening for new, amine based solvents for CO2 recovery from flue gas, two most promising solvent formulations, a 51 wt% New Solvent (NS) and a 26.7% AMP-11.9% HMDA mixture were selected and tested in an industrial pilot plant, mainly to identify the regeneration energy requirement. In

  2. Thermal effects in a depleted gas field by cold CO2 injection in the presence of methana

    NARCIS (Netherlands)

    Loeve, D.; Hofstee, C.; Maas, J.G.

    2014-01-01

    Depleted gas fields are seen as promising options for geological storage of CO2. The advantage of hydrocarbon fields are that the characteristics, such as the storage capacity and the proven sealing capacity are known. This means that only limited uncertainty remains after a technical feasibility st

  3. Thermal effects on a depleted gas field by cold CO2 injection in the prescence of methane

    NARCIS (Netherlands)

    Loeve, D.; Hofstee, C.; Maas, J.G.

    2013-01-01

    Depleted gas fields are seen as promising options for geological storage of CO2. The advantage of hydrocarbon fields are that the characteristics, such as the storage capacity and the proven sealing capacity are known. This means that only limited uncertainty remains after a technical feasibility st

  4. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture : Part B: Applications

    NARCIS (Netherlands)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo|info:eu-repo/dai/nl/412517361; Chiesa, Paolo; Romano, Matteo C.

    2016-01-01

    An important advantage of solid oxide fuel cells (SOFC) as future systems for large scale power generation is the possibility of being efficiently integrated with processes for CO2 capture. Focusing on natural gas power generation, Part A of this work assessed the performances of advanced

  5. Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

    Science.gov (United States)

    T. G. Soares Neto; J. A. Carvalho; C. A. G. Veras; E. C. Alvarado; R. Gielow; E. N. Lincoln; T. J. Christian; R. J. Yokelson; J. C. Santos

    2009-01-01

    Biomass consumption and CO2, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48% and the estimated average moisture content of fresh biomass was 42% on...

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

    Science.gov (United States)

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

    2017-01-13

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

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

    Science.gov (United States)

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

    2017-01-01

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

  8. Assessment of aversion to different concentrations of CO2 gas by weaned pigs using an approach-avoidance paradigm

    Science.gov (United States)

    The objective of this study was to examine the aversiveness of carbon dioxide (CO2) to weaned pigs using approach-avoidance and condition place avoidance paradigms. A preference-testing device was custom designed with two connected chambers maintained at static gas concentrations. The control chambe...

  9. The Evolution of High Temperature Gas Sensors.

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, F. H. (Fernando H.); Brosha, E. L. (Eric L.); Mukundan, R. (Rangachary)

    2001-01-01

    Gas sensor technology based on high temperature solid electrolytes is maturing rapidly. Recent advances in metal oxide catalysis and thin film materials science has enabled the design of new electrochemical sensors. We have demonstrated prototype amperometric oxygen sensors, nernstian potentiometric oxygen sensors that operate in high sulfur environments, and hydrocarbon and carbon monoxide sensing mixed potentials sensors. Many of these devices exhibit part per million sensitivities, response times on the order of seconds and excellent long-term stability.

  10. Energy requirements for CO2 capture from ambient air (DAC) competitive with capture from flue-gas (PCC)

    Science.gov (United States)

    Meinrenken, Christoph

    2015-03-01

    Capture of CO2, whether from a flue gas source (PCC) or from distributed sources via ambient air (DAC), is a key enabling technology to provide carbon for sustainable synthetic energy carriers such as solar fuels. Based on thermodynamic minimum considerations, DAC is often expected to require about 3 times more energy (per ton CO2 captured) than PCC because CO2 in ambient air is more dilute. Here, we calculate the energy required for a humidity swing-based DAC installation that uses an anionic exchange resin as sorbent. The calculation uses recently measured equilibrium CO2 loadings of the sorbent as function of partial CO2 pressure, temperature, and humidity. We calculate the installation's electricity consumption to be about 45 kJ per mole of pure CO2 at 1 bar (scenario-dependent). Furthermore, we estimate the amount of heat provided by ambient air and thus provide context of the overall energy and entropy balance and thermodynamic minimum views. The electricity consumption is competitive with typical parasitic loads of PCC-equipped coal-fired power plants (40-50 kJ per mole at same pressure) and significantly lower than predicted for other DAC installations such as Na(OH) sorbent-based systems. Our analyses elucidate why DAC is not always more energy-intensive that PCC, thus alleviating often cited concerns of significant cost impediments. Financial support by ABB for research presented herein is gratefully acknowledged.

  11. Utilization of simulated flue gas containing CO2, SO2, NO and ash for Chlorella fusca cultivation.

    Science.gov (United States)

    Duarte, Jessica Hartwig; Fanka, Letícia Schneider; Costa, Jorge Alberto Vieira

    2016-08-01

    Microalgae can use the CO2 from coal power plants in their metabolic pathways. However, these microorganisms must be able to tolerate other residues produced from burning coal. This study evaluated the wastes addition (CO2, SO2, NO and ash) present in the flue gas from a coal power plant on the growth parameters during culture, CO2 biofixation and on the biomass characterization of Chlorella fusca LEB 111. The SO2 and NO injection (until 400ppm) in cultivations did not markedly affect CO2 biofixation by microalga. The best CO2 biofixation efficiency was obtained with 10% CO2, 200ppm SO2 and NO and 40ppm ash (50.0±0.8%, w w(-1)), showing a specific growth rate of 0.18±0.01 d(-1). The C. fusca LEB 111 biomass composition was similar in all experiments with around 19.7% (w w(-1)) carbohydrates, 15.5% (w w(-1)) lipids and 50.2% (w w(-1)) proteins.

  12. Towards Enhanced Gas Sensor Performance with Fluoropolymer Membranes

    Directory of Open Access Journals (Sweden)

    Thorsten Graunke

    2016-09-01

    Full Text Available In this paper we report on how to increase the selectivity of gas sensors by using fluoropolymer membranes. The mass transport of polar and non-polar gases through a polymer membrane matrix was studied by systematic selection of polymers with different degrees of fluorination, as well as polymers whose monomers have ether groups (-O- in addition to fluorine groups (-F. For the study, a set of application-relevant gases including H2, CO, CO2, NO2, methane, ethanol, acetone, and acetaldehyde as well as various concentrations of relative humidity were used. These gases have different functional groups and polarities, yet have a similar kinetic diameter and are therefore typically difficult to separate. The concentrations of the gases were chosen according to international indicative limit values (TWA, STEL. To measure the concentration in the feed and permeate, we used tin-dioxide-based metal oxide gas sensors with palladium catalyst (SnO2:Pd, catalytic sensors (also SnO2:Pd-based and thermal conductivity sensors. This allows a close examination of the interdependence of diffusion and physicochemical operating principle of the sensor. Our goal is to increase the selectivity of gas sensors by using inexpensive fluoropolymer membranes. The measurements showed that through membranes with low polarity, preferably non-polar gases are transported. Furthermore, the degree of crystallization influences the permeability and selectivity of a polymer membrane. Basically the polar polymers showed a higher permeability to water vapor and polar substances than non-polar polymer membranes.

  13. 石英砂中CO2水合物的储气实验研究%Experimental Study on the Gas Storage Capacity of CO2 Hydrate in Quartzite

    Institute of Scientific and Technical Information of China (English)

    魏国栋

    2011-01-01

    The formation and dissociation of CO2 hydrate in porous quartzite with a normal diameter of 150 μm are studied. Under the conditions of 480 mL of water and excessive carbon dioxide,the greatest gas storage capacity of CO2 hydrate was 3. 078 mol%为研究CO2气体水合物在多孔介质中的储气量.在1.8L水合反应釜中放入粒径为150 μm(24~32目)石英砂,记录CO2气体水合物的生成与分解过程.实验结果表明,480 mL水和过量的CO2气体存在条件下,CO2水合物的最大储气量为3.078 mol.

  14. Biogenic emissions and CO 2 gas exchange investigated on four Mediterranean shrubs

    Science.gov (United States)

    Hansen, U.; van Eijk, J.; Bertin, N.; Staudt, M.; Kotzias, D.; Seufert, G.; Fugit, J.-L.; Torres, L.; Cecinato, A.; Brancaleoni, E.; Ciccioli, P.; Bomboi, T.

    In order to investigate the impact of plant physiology on emissions of biogenic volatile organic compounds monoterpene emission rates from Rosmarinus officinalis (L.) and Pistacia lentiscus (L.) and isoprene emission rates from Erica arborea (L.) and Myrtus communis (L.) were determined. The study, an activity in the framework of BEMA (Biogenic Emissions in the Mediterranean Area), was carried out in May 1994 at Castelporziano near Rome in Italy, using a dynamic enclosure technique combined with recording CO 2 gas exchange, temperature and irradiance data. The monoterpenes dominating the emission pattern were 1,8-cineol, α-pinene and β-pinene for rosemary and α-pinene, linalool and β-pinene + sabinene for pistachio. Total monoterpene emission rates standardized to 30°C of 1.84 ± 0.24 and 0.35 ± 0.04 μg Cg -1 dw h -1 were found for rosemary and pistachio, respectively (on a leaf dry weight basis). Myrtle emitted 22.2 ± 4.9 μg C g -1 dw h -1 at standard conditions (30°C, PAR 1000 μmol photons m -2 s -1 as isoprene and erica 5.61 μg C g -1 dw h -1 The carbon loss due to terpenoid emissions per photosynthetically carbon uptake was about 0.01-0.1% for the monoterpene emitters. The isoprene emitting shrubs lost 0-0.9% of the assimilated carbon. The rapid induction of emissions in the sun after temporary shading indicates that isoprene emissions were closely linked to photosynthesis. A higher proportion of the assimilated carbon was lost as isoprene under conditions of high light and temperature compared to the morning and evening hours.

  15. Direct gas-solid carbonation kinetics of steel slag and the contribution to in situ sequestration of flue gas CO(2) in steel-making plants.

    Science.gov (United States)

    Tian, Sicong; Jiang, Jianguo; Chen, Xuejing; Yan, Feng; Li, Kaimin

    2013-12-01

    Direct gas-solid carbonation of steel slag under various operational conditions was investigated to determine the sequestration of the flue gas CO2 . X-ray diffraction analysis of steel slag revealed the existence of portlandite, which provided a maximum theoretical CO2 sequestration potential of 159.4 kg CO 2 tslag (-1) as calculated by the reference intensity ratio method. The carbonation reaction occurred through a fast kinetically controlled stage with an activation energy of 21.29 kJ mol(-1) , followed by 10(3) orders of magnitude slower diffusion-controlled stage with an activation energy of 49.54 kJ mol(-1) , which could be represented by a first-order reaction kinetic equation and the Ginstling equation, respectively. Temperature, CO2 concentration, and the presence of SO2 impacted on the carbonation conversion of steel slag through their direct and definite influence on the rate constants. Temperature was the most important factor influencing the direct gas-solid carbonation of steel slag in terms of both the carbonation conversion and reaction rate. CO2 concentration had a definite influence on the carbonation rate during the kinetically controlled stage, and the presence of SO2 at typical flue gas concentrations enhanced the direct gas-solid carbonation of steel slag. Carbonation conversions between 49.5 % and 55.5 % were achieved in a typical flue gas at 600 °C, with the maximum CO2 sequestration amount generating 88.5 kg CO 2 tslag (-1) . Direct gas-solid carbonation of steel slag showed a rapid CO2 sequestration rate, high CO2 sequestration amounts, low raw-material costs, and a large potential for waste heat utilization, which is promising for in situ carbon capture and sequestration in the steel industry.

  16. Efficiency enhancement for natural gas liquefaction with CO2 capture and sequestration through cycles innovation and process optimization

    Science.gov (United States)

    Alabdulkarem, Abdullah

    Liquefied natural gas (LNG) plants are energy intensive. As a result, the power plants operating these LNG plants emit high amounts of CO2 . To mitigate global warming that is caused by the increase in atmospheric CO2, CO2 capture and sequestration (CCS) using amine absorption is proposed. However, the major challenge of implementing this CCS system is the associated power requirement, increasing power consumption by about 15--25%. Therefore, the main scope of this work is to tackle this challenge by minimizing CCS power consumption as well as that of the entire LNG plant though system integration and rigorous optimization. The power consumption of the LNG plant was reduced through improving the process of liquefaction itself. In this work, a genetic algorithm (GA) was used to optimize a propane pre-cooled mixed-refrigerant (C3-MR) LNG plant modeled using HYSYS software. An optimization platform coupling Matlab with HYSYS was developed. New refrigerant mixtures were found, with savings in power consumption as high as 13%. LNG plants optimization with variable natural gas feed compositions was addressed and the solution was proposed through applying robust optimization techniques, resulting in a robust refrigerant which can liquefy a range of natural gas feeds. The second approach for reducing the power consumption is through process integration and waste heat utilization in the integrated CCS system. Four waste heat sources and six potential uses were uncovered and evaluated using HYSYS software. The developed models were verified against experimental data from the literature with good agreement. Net available power enhancement in one of the proposed CCS configuration is 16% more than the conventional CCS configuration. To reduce the CO2 pressurization power into a well for enhanced oil recovery (EOR) applications, five CO2 pressurization methods were explored. New CO2 liquefaction cycles were developed and modeled using HYSYS software. One of the developed

  17. Analysis on CO2 Refrigeration Cycle with High Pressure Gas Vortex Expansion for Low Temperature%高压气体涡流膨胀的CO2低温制冷循环分析

    Institute of Scientific and Technical Information of China (English)

    赵家华; 宁静红

    2016-01-01

    通过设计高压气体涡流膨胀的CO2低温制冷循环,对其进行热力性能分析,并与两级节流中间完全冷却的CO2低温制冷循环的性能进行对比,得出高压气体涡流膨胀的CO2低温制冷循环存在获得最大性能系数的最优的高压压力。提高蒸发温度与中间压力,增大冷气流质量比,减少进入蒸发器的冷气流质量比,降低气体冷却器出口温度,均可提高高压气体涡流膨胀的CO2低温制冷循环的性能系数。在冷气流的质量比为0.6,冷气流进入蒸发器的质量比为0.2时,高压气体涡流膨胀的CO2低温制冷循环的最佳的性能系数较两级节流中间完全冷却的CO2低温制冷循环最佳的性能系数提高36.4%。随着气体冷却器出口温度的升高,高压气体涡流膨胀的CO2低温制冷循环的性能系数较两级节流中间完全冷却的CO2低温制冷循环的性能系数降低的幅度小。%The CO2 refrigeration cycle with high pressure gas vortex expansion for low temperature is designed. The thermal performances of this CO2 refrigeration cycle with high pressure gas vortex expansion for low temperature are analyzed and compared with that of the CO2 low temperature refrigeration cycle of two-stage throttle and complete cooling in middle. The following conclusions are obtained. The CO2 refrigeration cycle with high pressure gas vortex expansion for low temperature has the maximum coefficient of performance ( COP) at the optimal high pressure. The coefficient of performances of the CO2 refrigeration cycle with high pressure gas vortex expansion for low temperature can be improved by increasing the evaporation temperature, the middle pressure and the mass ratio of cold gas, by reducing the mass ratio of cold gas into evaporator, as well as by decreasing the temperature of gas-cooler out-let. At the mass ratio of cold gas is 0. 6 and the mass ratio of cold gas into evaporator is 0. 2, the maximum coeffi-cient of performance of

  18. Reactive transport modeling of the long-term effects of CO2 storage in the P18 depleted gas field

    Science.gov (United States)

    Tambach, T. J.; Koenen, M.; Wasch, L. J.; Loeve, D.; Maas, J. G.

    2012-04-01

    Depleted gas fields are an import CO2 storage sink for The Netherlands, with a total storage capacity of more than 3 Gtonne. The CO2 sources are located at relatively short distances from potential storage reservoirs and an infrastructure for (cross-border) gas transport over large distances already exists. Several depleted gas fields in the subsurface of the Netherlands have yet been evaluated as potential locations for CO2 storage (for example the K12-B field). The P18 gas field is located in the offshore of The Netherlands and is currently evaluated as potential CO2 storage reservoir. The aim of this study is to predict the long-term effects of CO2 injection into the P18 field using reactive transport modeling (TOUGHREACT). The storage reservoir is described using the mineralogy and petrophysical characteristics of three geological layers in a radial (R,Z) reservoir model with top depth of 3456 m, a thickness of 98 m, and 3300 grid cells. The initial reservoir temperature was defined as 90 degrees C with an initial (depletion) pressure of 20.0 bars. Capillary pressure curves are based on empirical relations. The CO2 is injected uniformly distributed over the model height, at a constant rate of 35 kg/s (1.1 Mton/year), and a temperature of 40 degrees C for 30 years. The well is then shut-in with a reservoir pressure of approximately 375 bar. The simulations are continued up to 10,000 years for computing the long-term effects in the reservoir. The results show that the near-well area is dried out during injection, leading to salt precipitation and reduced permeability during injection. Condensation of the evaporated water occurs outside the near-well area. Water imbibition is modelled after shut in of the well, leading to rewetting of the near-well area and redissolution of the salt. Most geochemical reactions need water to occur, including well-cement minerals, and therefore predictions of water flow after well shut-ins are important to take into account

  19. The influence of SO2 and NO2 impurities on CO2 gas hydrate formation and stability.

    Science.gov (United States)

    Beeskow-Strauch, Bettina; Schicks, Judith M; Spangenberg, Erik; Erzinger, Jörg

    2011-04-11

    The sequestration of industrially emitted CO(2) in gas hydrate reservoirs has been recently discussed as an option to reduce atmospheric greenhouse gas. This CO(2) contains, despite much effort to clean it, traces of impurities such as SO(2) and NO(2) . Here, we present results of a pilot study on CO(2) hydrates contaminated with 1% SO(2) or 1% NO(2) and show the impact on hydrate formation and stability. Microscopic observations show similar hydrate formation rates, but an increase in hydrate stability in the presence of SO(2). Laser Raman spectroscopy indicates a strong enrichment of SO(2) in the liquid and hydrate phase and its incorporation in both large and small cages of the hydrate lattice. NO(2) is not verifiable by laser Raman spectroscopy, only the presence of nitrate ions could be confirmed. Differential scanning calorimetry analyses show that hydrate stability and dissociation enthalpy of mixed CO(2)-SO(2) hydrates increase, but that only negligible changes arise in the presence of NO(2) impurities. X-ray diffraction data reveal the formation of sI hydrate in all experiments. The conversion rates of ice+gas to hydrate increase in the presence of SO(2), but decrease in the presence of NO(2). After hydrate dissociation, SO(2) and NO(2) dissolved in water and form strong acids.

  20. CO2 sequestration using waste concrete and anorthosite tailings by direct mineral carbonation in gas-solid-liquid and gas-solid routes.

    Science.gov (United States)

    Ben Ghacham, Alia; Cecchi, Emmanuelle; Pasquier, Louis-César; Blais, Jean-François; Mercier, Guy

    2015-11-01

    Mineral carbonation (MC) represents a promising alternative for sequestering CO2. In this work, the CO2 sequestration capacity of the available calcium-bearing materials waste concrete and anorthosite tailings is assessed in gas-solid-liquid and gas-solid routes using 18.2% flue CO2 gas. The objective is to screen for a better potential residue and phase route and as the ultimate purpose to develop a cost-effective process. The results indicate the possibility of removing 66% from inlet CO2 using waste concrete for the aqueous route. However, the results that were obtained with the carbonation of anorthosite were less significant, with 34% as the maximal percentage of CO2 removal. The difference in terms of reactivity could be explained by the accessibility to calcium. In fact, anorthosite presents a framework structure wherein the calcium is trapped, which could slow the calcium dissolution into the aqueous phase compared to the concrete sample, where calcium can more easily leach. In the other part of the study concerning gas-solid carbonation, the results of CO2 removal did not exceed 15%, which is not economically interesting for scaling up the process. The results obtained with waste concrete samples in aqueous phase are interesting. In fact, 34.6% of the introduced CO2 is converted into carbonate after 15 min of contact with the gas without chemical additives and at a relatively low gas pressure. Research on the optimization of the aqueous process using waste concrete should be performed to enhance the reaction rate and to develop a cost-effective process.

  1. Sensor platform for gas composition measurement

    NARCIS (Netherlands)

    De Graaf, G.; Bakker, F.; Wolffenbuttel, R.F.

    2011-01-01

    The gas sensor research presented here has a focus on the measurement of the composition of natural gas and gases from sustainable resources, such as biogas. For efficient and safe combustion, new sensor systems need to be developed to measure the composition of these new gases. In general about 6 g

  2. Computational fluid dynamic modeling of gas flow characteristics of the high-power CW CO2 laser

    Institute of Scientific and Technical Information of China (English)

    Hongyau Huang; Youqing Wang

    2011-01-01

    @@ To increase the photoelectronic conversion efficiency of the single discharge tube and to meet the requirements of the laser cutting system, optimization of the discharge tube structure and gas flow field is necessary. We present a computational fluid dynamic model to predict the gas flow characteristics of high-power fast-axial flow CO2 laser. A set of differential equations is used to describe the operation of the laser. Gas flow characteristics, are calculated. The effects of gas velocity and turbulence intensity on discharge stability are studied. Computational results are compared with experimental values, and a good agreement is observed. The method presented and the results obtained can make the design process more efficient.%To increase the photoelectronic conversion efficiency of the single discharge tube and to meet the requirements of the laser cutting system, optimization of the discharge tube structure and gas flow field is necessary. We present a computational fluid dynamic model to predict the gas flow characteristics of high-power fast-axial flow CO2 laser. A set of differential equations is used to describe the operation of the laser. Gas flow characteristics, are calculated. The effects of gas velocity and turbulence intensity on discharge stability are studied. Computational results are compared with experimental values, and a good agreement is observed. The method presented and the results obtained can make the design process more efficient.

  3. Gas Hydrates as a CH4 Source and a CO2 Sink: New Approaches Based on Fundamental Research

    Science.gov (United States)

    Schicks, J. M.; Spangenberg, E.; Erzinger, J.

    2007-12-01

    The huge amount of methane, stored in the gas hydrate reservoirs of the world suggests that natural gas hydrates may be used in the future as a source of energy. A first production test was performed during the Mallik 2002 Gas Hydrate Production Research Well Program, showing that the thermal stimulation of natural gas hydrates successfully results in methane production (Dallimore et al. 2005). However, regarding the energy balance, the most efficient method for methane production from hydrates still needs to be developed. From another point of view, the sequestration of CO2 in form of gas hydrates in (marine) sediments is an interesting idea. A combination of methane production from natural gas hydrates on the one hand and CO2 - sequestration on the other hand seems to be an obvious and ideal solution. Different studies on possible methods - e.g. the exchange of CH4 with CO2 in gas hydrates (Lee et al, 2003, Graue and Kvamme, 2006) - have been published recently and demonstrated that this could be a possible way, in principle. Our own investigations on the exchange of CH4 with gaseous CO2 showed that this reaction is much too slow and inefficient to be a reasonable approach. The exchange of only 20 percent CH4 with CO2 could be detected in stable structure I hydrate crystals after 120 hours. In addition, multicomponent hydrates containing higher hydrocarbons beside methane tend to be more stable than pure methane hydrates (Schicks et al, 2006). Therefore, the application of an additional and controlled method for CH4 -hydrate destabilization seems to be necessary and might lead to an efficient release of CH4 from and CO2 inclusion into hydrates. In any case, the question of process optimization still remains. In this contribution the chances and challenges of a combination of these two processes based on experimental data will be examined. Different kinds of experiments have been performed on natural marine and permafrost gas hydrates and synthesized clathrate

  4. Separation of H2O/CO2 Mixtures with Layered Adsorption Method for Greenhouse Gas Control

    Institute of Scientific and Technical Information of China (English)

    XU Dong; ZHANG Jun; LI Gang; XIAO Penny; ZHAI Yu-chun

    2012-01-01

    Multiple-layered vacuum swing adsorption technique was used and investigated in order to effectively keep the feed gas that flows into zeolite 13X zone being dry and keep the CAPEX down(not adding pre-treatment equipment).Activated carbon fiber(ACF) and alumina CDX were laid at the lower parts of the column as pre-layers to selectively adsorb moisture.Zeolite 13X was laid on the top of those two adsorbents as the main layer to capture CO2.Systematic cyclic experiments show that water vapor was successfully contained within the ACF and CDX layers at cyclic steady states.It was also found that ultimate vacuum pressure played a decisive factor for stabilizing the water front,and achieving good CO2 purity and recovery.The findings also reveal the pathway for large-scale CO2 capture process.

  5. Robust C–C bonded porous networks with chemically designed functionalities for improved CO2 capture from flue gas

    Directory of Open Access Journals (Sweden)

    Damien Thirion

    2016-10-01

    Full Text Available Effective carbon dioxide (CO2 capture requires solid, porous sorbents with chemically and thermally stable frameworks. Herein, we report two new carbon–carbon bonded porous networks that were synthesized through metal-free Knoevenagel nitrile–aldol condensation, namely the covalent organic polymer, COP-156 and 157. COP-156, due to high specific surface area (650 m2/g and easily interchangeable nitrile groups, was modified post-synthetically into free amine- or amidoxime-containing networks. The modified COP-156-amine showed fast and increased CO2 uptake under simulated moist flue gas conditions compared to the starting network and usual industrial CO2 solvents, reaching up to 7.8 wt % uptake at 40 °C.

  6. Robust C-C bonded porous networks with chemically designed functionalities for improved CO2 capture from flue gas.

    Science.gov (United States)

    Thirion, Damien; Lee, Joo S; Özdemir, Ercan; Yavuz, Cafer T

    2016-01-01

    Effective carbon dioxide (CO2) capture requires solid, porous sorbents with chemically and thermally stable frameworks. Herein, we report two new carbon-carbon bonded porous networks that were synthesized through metal-free Knoevenagel nitrile-aldol condensation, namely the covalent organic polymer, COP-156 and 157. COP-156, due to high specific surface area (650 m(2)/g) and easily interchangeable nitrile groups, was modified post-synthetically into free amine- or amidoxime-containing networks. The modified COP-156-amine showed fast and increased CO2 uptake under simulated moist flue gas conditions compared to the starting network and usual industrial CO2 solvents, reaching up to 7.8 wt % uptake at 40 °C.

  7. Robust C–C bonded porous networks with chemically designed functionalities for improved CO2 capture from flue gas

    Science.gov (United States)

    Thirion, Damien; Lee, Joo S; Özdemir, Ercan

    2016-01-01

    Effective carbon dioxide (CO2) capture requires solid, porous sorbents with chemically and thermally stable frameworks. Herein, we report two new carbon–carbon bonded porous networks that were synthesized through metal-free Knoevenagel nitrile–aldol condensation, namely the covalent organic polymer, COP-156 and 157. COP-156, due to high specific surface area (650 m2/g) and easily interchangeable nitrile groups, was modified post-synthetically into free amine- or amidoxime-containing networks. The modified COP-156-amine showed fast and increased CO2 uptake under simulated moist flue gas conditions compared to the starting network and usual industrial CO2 solvents, reaching up to 7.8 wt % uptake at 40 °C. PMID:28144294

  8. Temperature modulation of a catalytic gas sensor.

    Science.gov (United States)

    Brauns, Eike; Morsbach, Eva; Kunz, Sebastian; Baeumer, Marcus; Lang, Walter

    2014-10-29

    The use of catalytic gas sensors usually offers low selectivity, only based on their different sensitivities for various gases due to their different heats of reaction. Furthermore, the identification of the gas present is not possible, which leads to possible misinterpretation of the sensor signals. The use of micro-machined catalytic gas sensors offers great advantages regarding the response time, which allows advanced analysis of the sensor response. By using temperature modulation, additional information about the gas characteristics can be measured and drift effects caused by material shifting or environmental temperature changes can be avoided. In this work a miniaturized catalytic gas sensor which offers a very short response time (electronic device was developed, since theory shows that harmonics induced by the electronics must be avoided to generate a comprehensible signal.

  9. Perfusion and diffusion limitations in middle ear gas exchange: the exchange of CO2 as a test case.

    Science.gov (United States)

    Marcusohn, Yael; Ar, Amos; Dirckx, Joris J J

    2010-06-14

    A long standing debate on perfusion/diffusion limitations in the context of middle ear (ME) gas exchange was revisited using data obtained from previous iso-pressure gas-exchange measurements in different mammals. We tried to determine whether the exchange of CO(2) in the ME is limited by perfusion or by diffusion by comparing the mass specific cardiac output (msQ) and the mass specific initial CO(2) flow rate into air-washed MEs (msV(i) CO(2)) of rabbits and rats. Based on previously published allometry at rest, the msQ was 0.154 mL/(min g) in rabbits (mean body weight: 2800 g) and 0.259 mL/(min g) in rats (mean body weight: 179.1 g); msV(i) CO(2) (Delta t=0) was 0.109+/-0.047 microL/(h g) in rabbits (n=16) and 0.170+/-0.094 microL/(h g) in rats (n=9). Similar ratios were found when an allometric comparison was made between the ratio of msV(i) CO(2) (Delta t=0) (approximately 0.64), and the ratio of msQs (approximately 0.59) in rabbits and rats. If the active mucosal surface areas of MEs of rabbits and rats are directly proportional to their masses as are the masses of their hearts and if their msQs are proportional to the rates of blood flows in the ME mucosa, these results support the assumption that the exchange of CO(2) in the ME of mammals is mainly perfusion (and not diffusion) dependent.

  10. Desiccant dust and the use of CO2 gas as a mobility stimulant for bed bugs: a potential control solution?

    Science.gov (United States)

    Aak, Anders; Roligheten, Espen; Rukke, Bjørn Arne; Birkemoe, Tone

    2017-01-01

    The common bed bug (Cimex lectularius, Hemiptera; Cimicidae) infests homes and service industries, and the number of infestations has greatly increased over the past 20 years. At present, no cost-effective control methods are available, and eradication programs are expensive and laborious. We investigated the control potential of desiccant dust in combination with CO2 as a bed bug activity stimulant. An initial experiment with two desiccant dusts was followed by arena studies with varying doses, available hiding places and the presence or absence of host signals. Finally, we conducted a field experiment with Syloid 244FP with or without CO2 gas. Syloid was superior compared to diatomaceous earth, and effective at the concentration of 1.0 g/m(2) in the field experiment. The number of harborages and partial application of desiccant dust decreased mortality in the laboratory. Bed bug activation by CO2 appeared of minor importance in the arena studies, but was crucial for the eradication in the student dormitories. In fact, all 5 bed bug-infested dormitories with a combined treatment of desiccant dust and CO2 were freed of bed bugs, whereas eradication was not successful in any of the 6 dormitories with only desiccant dust treatment. The different results in the laboratory and field experiment were most likely caused by the longer activation and higher dose of CO2 used in the field experiment than the laboratory experiment. Our study showed that application of desiccant dust in combination with release of CO2 gas to mimic human presence is a promising option for bed bug control.

  11. Infrared Spectroscopy of Gas-Phase M(+)(CO2)n (M = Co, Rh, Ir) Ion-Molecule Complexes.

    Science.gov (United States)

    Iskra, Andreas; Gentleman, Alexander S; Kartouzian, Aras; Kent, Michael J; Sharp, Alastair P; Mackenzie, Stuart R

    2017-01-12

    The structures of gas-phase M(+)(CO2)n (M = Co, Rh, Ir; n = 2-15) ion-molecule complexes have been investigated using a combination of infrared resonance-enhanced photodissociation (IR-REPD) spectroscopy and density functional theory. The results provide insight into fundamental metal ion-CO2 interactions, highlighting the trends with increasing ligand number and with different group 9 ions. Spectra have been recorded in the region of the CO2 asymmetric stretch around 2350 cm(-1) using the inert messenger technique and their interpretation has been aided by comparison with simulated infrared spectra of calculated low-energy isomeric structures. All vibrational bands in the smaller complexes are blue-shifted relative to the asymmetric stretch in free CO2, consistent with direct binding to the metal center dominated by charge-quadrupole interactions. For all three metal ions, a core [M(+)(CO2)2] structure is identified to which subsequent ligands are less strongly bound. No evidence is observed in this size regime for complete activation or insertion reactions.

  12. Integrated CO2 capture-fixation chemistry via interfacial ionic liquid catalyst in laminar gas/liquid flow

    Science.gov (United States)

    Vishwakarma, Niraj K.; Singh, Ajay K.; Hwang, Yoon-Ho; Ko, Dong-Hyeon; Kim, Jin-Oh; Babu, A. Giridhar; Kim, Dong-Pyo

    2017-01-01

    Simultaneous capture of carbon dioxide (CO2) and its utilization with subsequent work-up would significantly enhance the competitiveness of CO2-based sustainable chemistry over petroleum-based chemistry. Here we report an interfacial catalytic reaction platform for an integrated autonomous process of simultaneously capturing/fixing CO2 in gas–liquid laminar flow with subsequently providing a work-up step. The continuous-flow microreactor has built-in silicon nanowires (SiNWs) with immobilized ionic liquid catalysts on tips of cone-shaped nanowire bundles. Because of the superamphiphobic SiNWs, a stable gas–liquid interface maintains between liquid flow of organoamines in upper part and gas flow of CO2 in bottom part of channel. The intimate and direct contact of the binary reagents leads to enhanced mass transfer and facilitating reactions. The autonomous integrated platform produces and isolates 2-oxazolidinones and quinazolines-2,4(1H,3H)-diones with 81–97% yields under mild conditions. The platform would enable direct CO2 utilization to produce high-valued specialty chemicals from flue gases without pre-separation and work-up steps. PMID:28262667

  13. 温室气体CO2的分离技术%Separation and Utilization of Greenhouse Gas CO2

    Institute of Scientific and Technical Information of China (English)

    李兰廷; 解强

    2005-01-01

    二氧化碳(CO2)是重要的温室气体,如何将CO2从混合气体中分离出来并加以合理利用,是消除温室效应的根本所在.按照不同的CO2分离方法,对其分离机理、分离状况和分离效果进行了详细的阐述;对CO2的分离和利用前景提出了自己的看法,以期发现CO2分离和利用双赢的新方法,并对生产实践能有所帮助.

  14. The correlation and level of agreement between end-tidal and blood gas pCO2 in children with respiratory distress: a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Alexander Jamin L

    2009-03-01

    Full Text Available Abstract Background To investigate the correlation and level of agreement between end-tidal carbon dioxide (EtCO2 and blood gas pCO2 in non-intubated children with moderate to severe respiratory distress. Methods Retrospective study of patients admitted to an intermediate care unit (InCU at a tertiary care center over a 20-month period with moderate to severe respiratory distress secondary to asthma, bronchiolitis, or pneumonia. Patients with venous pCO2 (vpCO2 and EtCO2 measurements within 10 minutes of each other were eligible for inclusion. Patients with cardiac disease, chronic pulmonary disease, poor tissue perfusion, or metabolic abnormalities were excluded. Results Eighty EtCO2-vpCO2 paired values were available from 62 patients. The mean ± SD for EtCO2 and vpCO2 was 35.7 ± 10.1 mmHg and 39.4 ± 10.9 mmHg respectively. EtCO2 and vpCO2 values were highly correlated (r = 0.90, p SD between EtCO2 and vpCO2 was -3.68 ± 4.70 mmHg. The 95% level of agreement ranged from -12.88 to +5.53 mmHg. EtCO2 was found to be more accurate when vpCO2 was 35 mmHg or lower. Conclusion EtCO2 is correlated highly with vpCO2 in non-intubated pediatric patients with moderate to severe respiratory distress across respiratory illnesses. Although the level of agreement between the two methods precludes the overall replacement of blood gas evaluation, EtCO2 monitoring remains a useful, continuous, non-invasive measure in the management of non-intubated children with moderate to severe respiratory distress.

  15. Simultaneous microalgal biomass production and CO2 fixation by cultivating Chlorella sp. GD with aquaculture wastewater and boiler flue gas.

    Science.gov (United States)

    Kuo, Chiu-Mei; Jian, Jhong-Fu; Lin, Tsung-Hsien; Chang, Yu-Bin; Wan, Xin-Hua; Lai, Jinn-Tsyy; Chang, Jo-Shu; Lin, Chih-Sheng

    2016-12-01

    A microalgal strain, Chlorella sp. GD, cultivated in aquaculture wastewater (AW) aerated with boiler flue gas, was investigated. When AW from a grouper fish farm was supplemented with additional nutrients, the microalgal biomass productivity after 7days of culture was 0.794gL(-1)d(-1). CO2 fixation efficiencies of the microalgal strains aerated with 0.05, 0.1, 0.2, and 0.3vvm of boiler flue gas (containing approximately 8% CO2) were 53, 51, 38, and 30%, respectively. When the microalgal strain was cultured with boiler flue gas in nutrient-added AW, biomass productivity increased to 0.892gL(-1)d(-1). In semi-continuous cultures, average biomass productivities of the microalgal strain in 2-day, 3-day, and 4-day replacement cultures were 1.296, 0.985, and 0.944gL(-1)d(-1), respectively. These results demonstrate the potential of using Chlorella sp. GD cultivations in AW aerated with boiler flue gas for reusing water resources, reducing CO2 emission, and producing microalgal biomass.

  16. Influence of SO2 in incineration flue gas on the sequestration of CO2 by municipal solid waste incinerator fly ash

    Institute of Scientific and Technical Information of China (English)

    Jianguo Jiang; Sicong Tian; Chang Zhang

    2013-01-01

    The influence of CO2 content and presence of SO2 on the sequestration of CO2 by municipal solid waste incinerator (MSWI) fly ash was studied by investigating the carbonation reaction of MSWI fly ash with different combinations of simulated flue gas.The reaction between fly ash and 100% CO2 was relatively fast; the uptake of CO2 reached 87 g CO2/kg ash,and the sequestered CO2 could be entirely released at high temperatures.When CO2 content was reduced to 12%,the reaction rate decreased; the uptake fell to 41 g CO2/kg ash,and 70.7% of the sequestered CO2 could be released.With 12% CO2 in the presence of SO2,the reaction rate significantly decreased; the uptake was just 17 g CO2/kg ash,and only 52.9% of the sequestered CO2 could be released.SO2 in the simulated gas restricted the ability of fly ash to sequester CO2 because it blocked the pores of the ash.

  17. Sub- T g Cross-Linking of a Polyimide Membrane for Enhanced CO 2 Plasticization Resistance for Natural Gas Separation

    KAUST Repository

    Qiu, Wulin

    2011-08-09

    Decarboxylation-induced thermal cross-linking occurs at elevated temperatures (∼15 °C above glass transition temperature) for 6FDA-DAM:DABA polyimides, which can stabilize membranes against swelling and plasticization in aggressive feed streams. Despite this advantage, such a high temperature might result in collapse of substructure and transition layers in the asymmetric structure of a hollow fibers based on such a material. In this work, the thermal cross-linking of the 6FDA-DAM:DABA at temperatures much below the glass transition temperature (∼387 °C by DSC) was demonstrated. This sub-Tg cross-linking capability enables extension to asymmetric structures useful for large scale membranes. The resulting polymer membranes were characterized by swelling in known solvents for the un-cross-linked materials, TGA analysis, and permeation tests of aggressive gas feed stream at higher pressure. The annealing temperature and time clearly influence the degree of cross-linking of the membranes, and results in a slight difference in selectivity for membranes under various cross-linking conditions. Results indicate that the sub-Tg thermal cross-linking of 6FDA-DAM:DABA dense film membrane can be carried out completely even at a temperature as low as 330 °C. Permeabilities were tested for the polyimide membranes using both pure gases (He, O2, N2, CH4, CO2) and mixed gases (CO2/CH4). The selectivity of the cross-linked membrane can be maintained even under very aggressive CO2 operating conditions that are not possible without cross-linking. Moreover, the plasticization resistance was demonstrated up to 700 psia for pure CO 2 gas or 1000 psia for 50% CO2 mixed gas feeds. © 2011 American Chemical Society.

  18. Natural gas and CO2 price variation: impact on the relative cost-efficiency of LNG and pipelines.

    Science.gov (United States)

    Ulvestad, Marte; Overland, Indra

    2012-06-01

    THIS ARTICLE DEVELOPS A FORMAL MODEL FOR COMPARING THE COST STRUCTURE OF THE TWO MAIN TRANSPORT OPTIONS FOR NATURAL GAS: liquefied natural gas (LNG) and pipelines. In particular, it evaluates how variations in the prices of natural gas and greenhouse gas emissions affect the relative cost-efficiency of these two options. Natural gas is often promoted as the most environmentally friendly of all fossil fuels, and LNG as a modern and efficient way of transporting it. Some research has been carried out into the local environmental impact of LNG facilities, but almost none into aspects related to climate change. This paper concludes that at current price levels for natural gas and CO2 emissions the distance from field to consumer and the volume of natural gas transported are the main determinants of transport costs. The pricing of natural gas and greenhouse emissions influence the relative cost-efficiency of LNG and pipeline transport, but only to a limited degree at current price levels. Because more energy is required for the LNG process (especially for fuelling the liquefaction process) than for pipelines at distances below 9100 km, LNG is more exposed to variability in the price of natural gas and greenhouse gas emissions up to this distance. If the prices of natural gas and/or greenhouse gas emission rise dramatically in the future, this will affect the choice between pipelines and LNG. Such a price increase will be favourable for pipelines relative to LNG.

  19. CORRELATION BETWEEN POLYMER PACKING AND GAS TRANSPORT PROPERTIES FOR CO2/N2 SEPARATION IN GLASSY FLUORINATED POLYIMIDE MEMBRANE

    Directory of Open Access Journals (Sweden)

    P. C. TAN

    2016-07-01

    Full Text Available Gas separation performance of a membrane highly hinges on its physical properties. In this study, the interplay between polymer packing of a membrane and its gas transport behaviours (permeability and selectivity was investigated through a series of 6FDA-DAM:DABA (3:2 polyimide membranes with different polymer compactness. The chemical structure and the polymer packing of the resulting membrane were characterized using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR and packing density measurement, respectively. CO2/N2 separation efficiency of the membrane was evaluated at 25oC with feed pressure up to 6 bar. N2 permeability was found to rely on the membrane’s packing density, which signified its greater dependence on molecular sieving. In contrast, sorption showed a more vital role in determining the CO2 permeability. In this work, the membrane with a final thickness of 97±2 µm had successfully surpassed the Robeson’s 2008 upper bound plot with a CO2 permeability of 83 Barrer and CO2/N2 selectivity of 97 at 3 bar permeation.

  20. CO2 Capture from Flue gas using Amino acid salt solutions

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai

    to storage. Typical solvents for the process are based on aqueous solutions of alkanolamines, such as mono-ethanolamine (MEA), but their use implies economic disadvantages and environmental complications. Amino acid salt solutions have emerged as an alternative to the alkanolamines, partlybecause....../or amino acid salt concentrations. The formation of solids poses challenges, but it also holds the promise for improving the efficiency of the capture process. This project focuses on phase equilibrium experiments of five systems CO2 + amino acid salt + H2O, at conditions relevant for the CO2 capture...... process. Also, attention is given to the chemical compositions of the precipitations, which forms as a result of CO2 absorption into the five amino acid salt solutions. Phase equilibrium data are needed to develop safe and economically viable capture processes. Two different experimental apparatuses were...

  1. A Large Scale Virtual Gas Sensor Array

    Science.gov (United States)

    Ziyatdinov, Andrey; Fernández-Diaz, Eduard; Chaudry, A.; Marco, Santiago; Persaud, Krishna; Perera, Alexandre

    2011-09-01

    This paper depicts a virtual sensor array that allows the user to generate gas sensor synthetic data while controlling a wide variety of the characteristics of the sensor array response: arbitrary number of sensors, support for multi-component gas mixtures and full control of the noise in the system such as sensor drift or sensor aging. The artificial sensor array response is inspired on the response of 17 polymeric sensors for three analytes during 7 month. The main trends in the synthetic gas sensor array, such as sensitivity, diversity, drift and sensor noise, are user controlled. Sensor sensitivity is modeled by an optionally linear or nonlinear method (spline based). The toolbox on data generation is implemented in open source R language for statistical computing and can be freely accessed as an educational resource or benchmarking reference. The software package permits the design of scenarios with a very large number of sensors (over 10000 sensels), which are employed in the test and benchmarking of neuromorphic models in the Bio-ICT European project NEUROCHEM.

  2. Optical sensors of gas on the basis of semiconductor sources of infrared emission

    Directory of Open Access Journals (Sweden)

    Kabatsiy V. N.

    2008-08-01

    Full Text Available Various constructions of optic sensors of gas and gas analyzers on their basis with the use of low-powered semiconductor sources of infrared emission for wave-length of 2,5–5,0 mm made on basis of InGaAs/InAs and InAsSbP/InAs heterostructures are worked out. The experimental results demonstrating the ability of application of semiconductor sources of infrared emission in optic sensors for measuring of metan concentration (CH4 and carbon dioxide (CO2 are given. The availability of use of such sensors in the gas analysis equipment of new generation is shown.

  3. Can CO2 be Used as a Pressurizing Gas for Mars Greenhouses?

    Science.gov (United States)

    Wheeler, Raymond M.

    2000-01-01

    The possibility of using plants to provide oxygen (O2) and food during space travel has been discussed and studied for nearly 50 years. The concept is based on the process of photosynthesis, which uses CO2 as a substrate and is driven by light (photosynthetically active radiation - PAR0 in the 400 to 700 nm waveband. In addition to the CO2 and light, the plants would require a controlled environment with acceptable temperatures (approx. 10 to 35 C) and humidities (approx. 40 to 85 %), adequate supplies of water and mineral nutrients, and minimum levels of oxygen to sustain respiration.

  4. Mixed-linker zeolitic imidazolate framework mixed-matrix membranes for aggressive CO2 separation from natural gas

    KAUST Repository

    Thompson, Joshua A.

    2014-07-01

    Zeolitic imidazolate framework (ZIF) materials are a promising subclass of metal-organic frameworks (MOF) for gas separations. However, due to the deleterious effects of gate-opening phenomena associated with organic linker rotation near the limiting pore apertures of ZIFs, there have been few demonstrations of improved gas separation properties over pure polymer membranes when utilizing ZIF materials in composite membranes for CO2-based gas separations. Here, we report a study of composite ZIF/polymer membranes, containing mixed-linker ZIF materials with ZIF-8 crystal topologies but composed of different organic linker compositions. Characterization of the mixed-linker ZIFs shows that the mixed linker approach offers control over the porosity and pore size distribution of the materials, as determined from nitrogen physisorption and Horváth-Kawazoe analysis. Single gas permeation measurements on mixed-matrix membranes reveal that inclusion of mixed-linker ZIFs yields membranes with better ideal CO2/CH4 selectivity than membranes containing ZIF-8. This improvement is shown to likely occur from enhancement in the diffusion selectivity of the membranes associated with controlling the pore size distribution of the ZIF filler. Mixed-gas permeation experiments show that membranes with mixed-linker ZIFs display an effective plasticization resistance that is not typical of the pure polymeric matrix. Overall, we demonstrate that mixed-linker ZIFs can improve the gas separation properties in composite membranes and may be applicable to aggressive CO2 concentrations in natural gas feeds. © 2013 Elsevier Inc. All rights reserved.

  5. Comparative CO2 flux measurements by eddy covariance technique using open- and closed-path gas analysers over the equatorial Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Fumiyoshi Kondo

    2012-04-01

    Full Text Available Direct comparison of air–sea CO2 fluxes by open-path eddy covariance (OPEC and closed-path eddy covariance (CPEC techniques was carried out over the equatorial Pacific Ocean. Previous studies over oceans have shown that the CO2 flux by OPEC was larger than the bulk CO2 flux using the gas transfer velocity estimated by the mass balance technique, while the CO2 flux by CPEC agreed with the bulk CO2 flux. We investigated a traditional conflict between the CO2 flux by the eddy covariance technique and the bulk CO2 flux, and whether the CO2 fluctuation attenuated using the closed-path analyser can be measured with sufficient time responses to resolve small CO2 flux over oceans. Our results showed that the closed-path analyser using a short sampling tube and a high volume air pump can be used to measure the small CO2 fluctuation over the ocean. Further, the underestimated CO2 flux by CPEC due to the attenuated fluctuation can be corrected by the bandpass covariance method; its contribution was almost identical to that of H2O flux. The CO2 flux by CPEC agreed with the total CO2 flux by OPEC with density correction; however, both of them are one order of magnitude larger than the bulk CO2 flux.

  6. Basic results of oil field experiments which justify the development of oil and gas formations using CO2 in Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Nemeth, E.

    1984-01-01

    An oil field experiment begun in 1969 and conducted in the 1970s in the K-2 collector of the Budafa deposit is the basis for developing the deposits of oil and gas of Budafa and Lovasi by secondary and tertiary methods using CO2. The condition of the formation at the onset of pumping in the carbon dioxide is briefly described. The results of the experiment are confirmed by the substantial increase and improvement in the daily flow rates of wells and the oil extraction factor. The mechanism of displacement is analyzed, along with the factors which effect the results, and their value. The question about the role of clay minerals in the CO2, oil, water and rock system is examined along with methods for regulating the rate of pumping gas and the withdrawal rate.

  7. Wintertime CO2 fluxes in an Arctic polynya using eddy covariance: Evidence for enhanced air-sea gas transfer during ice formation

    National Research Council Canada - National Science Library

    B. G. T. Else; T. N. Papakyriakou; R. J. Galley; W. M. Drennan; L. A. Miller; H. Thomas

    2011-01-01

      High rates of CO2 exchange were observed over flaw leads using eddy covariance Enhanced gas exchange is hypothesized to be due to ice formation in leads Enhanced gas exchange is important to annual...

  8. A dynamic leaf gas-exchange strategy is conserved in woody plants under changing ambient CO2: evidence from carbon isotope discrimination in paleo and CO2 enrichment studies

    Science.gov (United States)

    Rising atmospheric [CO2], ca, is expected to affect stomatal regulation of leaf gas-exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water and nutrient cycling of forests. Researchers have reported that stomata regulate leaf gas-exchange around &ldq...

  9. Wettability determination by contact angle measurements: hvbB coal-water system with injection of synthetic flue gas and CO2.

    Science.gov (United States)

    Shojai Kaveh, Narjes; Rudolph, E Susanne J; Wolf, Karl-Heinz A A; Ashrafizadeh, Seyed Nezameddin

    2011-12-01

    Geological sequestration of pure carbon dioxide (CO(2)) in coal is one of the methods to sequester CO(2). In addition, injection of CO(2) or flue gas into coal enhances coal bed methane production (ECBM). The success of this combined process depends strongly on the wetting behavior of the coal, which is function of coal rank, ash content, heterogeneity of the coal surface, pressure, temperature and composition of the gas. The wetting behavior can be evaluated from the contact angle of a gas bubble, CO(2) or flue gas, on a coal surface. In this study, contact angles of a synthetic flue gas, i.e. a 80/20 (mol%) N(2)/CO(2) mixture, and pure CO(2) on a Warndt Luisenthal (WL) coal have been determined using a modified pendant drop cell in a pressure range from atmospheric to 16 MPa and a constant temperature of 318 K. It was found that the contact angles of flue gas on WL coal were generally smaller than those of CO(2). The contact angle of CO(2) changes from water-wet to gas-wet by increasing pressure above 8.5 MPa while the one for the flue gas changes from water-wet to intermediate-wet by increasing pressure above 10 MPa.

  10. Application of 13Cr Steel in CO2 Gas Well Completion Packer%13Cr 钢在含 CO2气井用完井封隔器上的应用

    Institute of Scientific and Technical Information of China (English)

    孙志扬; 罗君; 姜建平; 焦阳

    2016-01-01

    CO2腐蚀是世界石油工业中常见的腐蚀类型,CO2溶于水后对钢铁具有极强的腐蚀性,会对油套管及井下工具产生严重腐蚀。13Cr 钢具有良好的抗 CO2腐蚀性能,可以满足含 CO2气井用完井封隔器的使用要求。本文主要讲述了13Cr 钢在含 CO2气井用完井封隔器上的应用情况,说明了含 CO2气井用完井封隔器材料选用原则,针对13Cr 钢在加工过程中发生的问题,给出了解决方案,并介绍了这种完井封隔器的室内试验情况。%CO2 corrosion is a common type of corrosion in petroleum industry. However, with excellent CO2 corrosion resistance, the 13Cr steel can satisfy the requirements of CO2 gas well completion packer. This paper mainly described the application of 13Cr steel in CO2 gas well completion packer, explained the material selection principle, provided solutions for processing problems, and introduced the indoor test results.

  11. Adsorptive separation of CO2/CH4/CO gas mixtures at high pressures

    NARCIS (Netherlands)

    Krishna, R.

    2012-01-01

    The major objective of this communication is to compare the performance of three metal-organic frameworks (MOFs): CuBTC, MIL-101, and Zn(bdc)dabco, with that of NaX zeolite for selective adsorption of CO2 from mixtures containing CH4 and CO in a pressure swing adsorption (PSA) unit operating at

  12. Basic petrochemicals from natural gas, coal and biomass: energy use and CO2 emissions

    NARCIS (Netherlands)

    Ren, T.; Patel, M.K.|info:eu-repo/dai/nl/18988097X

    2009-01-01

    While high-value basic petrochemicals (HVCs) are mostly produced through conventional naphtha and ethane-based process routes, it is also possible to produce them through coal and biomass-based routes. In this paper, we compared these routes in terms of energy use and CO2 emissions per ton of HVCs.

  13. Integrated underground gas storage of CO2 and CH4 to decarbonize the "power-to-gas-to-gas-to-power" technology

    Science.gov (United States)

    Kühn, Michael; Streibel, Martin; Nakaten, Natalie; Kempka, Thomas

    2014-05-01

    Massive roll-out of renewable energy production units (wind turbines and solar panels) leads to date to excess energy which cannot be consumed at the time of production. So far, long-term storage is proposed via the so called 'power-to-gas' technology. Energy is transferred to methane gas and subsequently combusted for power production - 'power-to-gas-to-power' (PGP) - when needed. PGP profits from the existing infrastructure of the gas market and could be deployed immediately. However, major shortcoming is the production of carbon dioxide (CO2) from renewables and its emission into the atmosphere. We present an innovative idea which is a decarbonised extension of the PGP technology. The concept is based on a closed carbon cycle: (1) Hydrogen (H2) is generated from renewable energy by electrolysis and (2) transformed into methane (CH4) with CO2 taken from an underground geological storage. (3) CH4 produced is stored in a second storage underground until needed and (4) combusted in a combined-cycled power plant on site. (5) CO2 is separated during energy production and re-injected into the storage formation. We studied a show case for the cities Potsdam and Brandenburg/Havel in the Federal State of Brandenburg in Germany to determine the energy demand of the entire process chain and the costs of electricity (COE) using an integrated techno-economic modelling approach (Nakaten et al. 2014). Taking all of the individual process steps into account, the calculation shows an overall efficiency of 27.7 % (Streibel et al. 2013) with total COE of 20.43 euro-cents/kWh (Kühn et al. 2013). Although the level of efficiency is lower than for pump and compressed air storage, the resulting costs are similar in magnitude, and thus competitive on the energy storage market. The great advantage of the concept proposed here is that, in contrast to previous PGP approaches, this process is climate-neutral due to CO2 utilisation. For that purpose, process CO2 is temporally stored in an

  14. CO2 laser modeling

    Science.gov (United States)

    Johnson, Barry

    1992-01-01

    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  15. A feasibility study on the bioconversion of CO2 and H2 to biomethane by gas sparging through polymeric membranes.

    Science.gov (United States)

    Díaz, I; Pérez, C; Alfaro, N; Fdz-Polanco, F

    2015-06-01

    In this study, the potential of a pilot hollow-fiber membrane bioreactor for the conversion of H2 and CO2 to CH4 was evaluated. The system transformed 95% of H2 and CO2 fed at a maximum loading rate of 40.2 [Formula: see text] and produced 0.22m(3) of CH4 per m(3) of H2 fed at thermophilic conditions. H2 mass transfer to the liquid phase was identified as the limiting step for the conversion, and kLa values of 430h(-1) were reached in the bioreactor by sparging gas through the membrane module. A simulation showed that the bioreactor could upgrade biogas at a rate of 25m(3)/mR(3)d, increasing the CH4 concentration from 60 to 95%v. This proof-of-concept study verified that gas sparging through a membrane module can efficiently transfer H2 from gas to liquid phase and that the conversion of H2 and CO2 to biomethane is feasible on a pilot scale at noteworthy load rates.

  16. Photosynthetic pigments and gas exchange in castor bean under conditions of above the optimal temperature and high CO2

    Directory of Open Access Journals (Sweden)

    Fabiola França Silva

    2015-08-01

    Full Text Available The castor bean plant, a Euphorbiaceae oil seed C3-metabolism rustic and drought-resistant plant, is cultivated in a wide range of environments due to its good adaptive capacity. However, given the current environmental changes, many biochemical and physiological impacts may affect the productivity of important crops, such as castor bean. This work aimed to evaluate the impacts of the castor bean gas exchange in response to high temperature and increased CO2concentration.Our experiment was conducted in a phytotron located at Embrapa Algodão in 2010. We adopted a completely randomized design, with four treatments in a factorial combination of two temperatures (30/20 and 37/30°C and two CO2 levels (400 and 800 mmol L-1; four replications were performed, obtained in five surveys over the growth cycle, for a total of 80 sample units. An infrared gas analyzer (IRGA - Infra Red Gas Analyzer was used for the quantification of the photosynthetic rate, stomatal conductance and transpiration. An increase in the atmospheric CO2 concentration and temperature negatively affected the physiology of the castor bean plants, decreasing the net rate of photosynthesis, transpiration and stomatal conductance.

  17. 开停真空泵控制变压吸附产品气中 CO2含量总结%CO2 Content Control in PSA Production Gas by Starting-Stopping the Vacuum Pump

    Institute of Scientific and Technical Information of China (English)

    胡志忠

    2014-01-01

    After the flash steam PSA device was put into operation ,to control the CO2 content in the production gas ,tried adjusting the vacuum degree by starting‐stopping the vacuum pump .%介绍闪蒸气变压吸附装置投用后,尝试采用开停真空泵、调整真空度的办法,控制产品气中CO2含量的情况。

  18. Evaluating Impacts of CO2 and CH4 Gas Intrusion into an Unconsolidated Aquifer: Fate of As and Cd

    Energy Technology Data Exchange (ETDEWEB)

    Lawter, Amanda R.; Qafoku, Nikolla; Shao, Hongbo; Bacon, Diana H.; Brown, Christopher F.

    2015-07-10

    Abstract The sequestration of carbon dioxide (CO2) in deep underground reservoirs has been identified as an important strategy to decrease atmospheric CO2 levels and mitigate global warming, but potential risks on overlying aquifers currently lack a complete evaluation. In addition to CO2, other gases such as methane (CH4) may be present in storage reservoirs. This paper explores for the first time the combined effect of leaking CO2 and CH4 gasses on the fate of major, minor and trace elements in an aquifer overlying a potential sequestration site. Emphasis is placed on the fate of arsenic (As) and cadmium (Cd) released from the sediments or present as soluble constituents in the leaking brine. Results from macroscopic batch and column experiments show that the presence of CH4 (at a concentration of 1 % in the mixture CO2/CH4) does not have a significant effect on solution pH or the concentrations of most major elements (such as Ca, Ba, and Mg). However, the concentrations of Mn, Mo, Si and Na are inconsistently affected by the presence of CH4 (i.e., in at least one sediment tested in this study). Cd is not released from the sediments and spiked Cd is mostly removed from the aqueous phase most likely via adsorption. The fate of sediment associated As [mainly sorbed arsenite or As(III) in minerals] and spiked As [i.e., As5+] is complex. Possible mechanisms that control the As behavior in this system are discussed in this paper. Results are significant for CO2 sequestration risk evaluation and site selection and demonstrate the importance of evaluating reservoir brine and gas stream composition during site selection to ensure the safest site is being chosen.

  19. MEMS device for mass market gas and chemical sensors

    Science.gov (United States)

    Kinkade, Brian R.; Daly, James T.; Johnson, Edward A.

    2000-08-01

    Gas and chemical sensors are used in many applications. Industrial health and safety monitors allow companies to meet OSHA requirements by detecting harmful levels of toxic or combustible gases. Vehicle emissions are tested during annual inspections. Blood alcohol breathalizers are used by law enforcement. Refrigerant leak detection ensures that the Earth's ozone layer is not being compromised. Industrial combustion emissions are also monitored to minimize pollution. Heating and ventilation systems watch for high levels of carbon dioxide (CO2) to trigger an increase in fresh air exchange. Carbon monoxide detectors are used in homes to prevent poisoning from poor combustion ventilation. Anesthesia gases are monitored during a patients operation. The current economic reality is that two groups of gas sensor technologies are competing in two distinct existing market segments - affordable (less reliable) chemical reaction sensors for consumer markets and reliable (expensive) infrared (IR) spectroscopic sensors for industrial, laboratory, and medical instrumentation markets. Presently high volume mass-market applications are limited to CO detectros and on-board automotive emissions sensors. Due to reliability problems with electrochemical sensor-based CO detectors there is a hesitancy to apply these sensors in other high volume applications. Applications such as: natural gas leak detection, non-invasive blood glucose monitoring, home indoor air quality, personal/portable air quality monitors, home fire/burnt cooking detector, and home food spoilage detectors need a sensor that is a small, efficient, accurate, sensitive, reliable, and inexpensive. Connecting an array of these next generation gas sensors to wireless networks that are starting to proliferate today creates many other applications. Asthmatics could preview the air quality of their destinations as they venture out into the day. HVAC systems could determine if fresh air intake was actually better than the air

  20. Between ice and gas: CO2 on the icy satellites of Jupiter and Saturn

    Science.gov (United States)

    Hibbitts, C.

    2010-12-01

    CO2 exists in the surfaces of the icy Galilean and Saturnian satellites [1-6], yet despite its discovery over a decade ago on Ganymede, and five years ago on the Saturnian satellites, its nature is still debated [7]. On the Galilean satellites Callisto and Ganymede, the CO2 that is detected is bound to, or trapped within, the non-ice materials that prevent it from sublimating or otherwise escaping from the surface. On Europa, it resides within both the ice and nonice materials [8,9]. While greater abundances of CO2 may exist in the interiors of these moons, or small amounts may be continually created through particle bombardment of the surface, the observed CO2 is only a trace material, with a few hundred molecules responsible for the deepest absorption features and an estimated molar abundance of 0.1% [2; 10-12]. Yet its presence may provide essential clues to processes that shape the surfaces of the moon [13] and potentially key to understanding the composition of potential oceans in the subsurfaces. We continue measurements of the infrared properties associated with CO2 adsorbed onto nonice materials under pressures and at temperatures relevant to these icy satellites using bidirectional reflectance spectroscopy from ~ 1.5 to 5.5 μm. Previous measurements, using transmission spectroscopy, demonstrated both a compositional and a temperature dependence on the spectral signature of adsorbed CO2 [14]. Bidirectional spectroscopy enables detection of lower concentrations of adsorbate on fine-grained materials such as clays due to their large surface area to volume ratios and thus large surface areas that may be covered by adsorbate [15]. The effectiveness of transmission spectroscopy was also limited by the strong absorption of light within the pressed sample and its impermeability, which limited the coverage by adsorbate to the pellet’s outer surface. All measurements demonstrate that CO2 adsorbs onto montmorillonite clays, possibly due to its quadrupole moment

  1. 普通小球藻固定模拟烟气中CO2的实验研究%Experimental study on CO2fixation from simulated flue gas byChlorella vulgaris

    Institute of Scientific and Technical Information of China (English)

    罗梦圆; 杨俊红; 巩启涛; 左鹏鹏; 康利改

    2015-01-01

    Theglobe warming caused by elevated CO2 level in atmosphere is of big concerns. Biological CO2 mitigation by microalgae is a hot issue. In this paper,Chlorella vulgaris(FACHB-1227) were cultured with SE medium in concentric-tube photobioreactor with aeration pores in inner tube. Cultures in the photobioreactor were aerated intermittently with simulated flue gas which contains different CO2 concentrations,i.e. 5%,10%,15% and 20%. In this work,cell density and CO2fixation rate were used to describe the growth and carbon fixation capacity ofChlorella vulgaris. After 17 days of cultivation,Chlorella vulgarispresented better results for all parameters under simulated flue gas with 10% CO2,the maximum cell concentration ofChlorella vulgariswas 8.76×106cells/mL, increasing 54.23%,66.86% and 76.97% compared to 5%CO2,15%CO2and 20% CO2 groups, respectively; the maximum CO2 fixation rate were 30.18mg/(L·d),increasing 57.27%,70.89% and 81.91% compared to 5% CO2,15%CO2 and 20%CO2 groups,respectively. The results show that Chlorella vulgaris shows a better capacity of CO2fixation in simulated flue gas with 10% CO2.%大气中 CO2浓度增加造成的全球变暖已成为一个严峻的环境问题,利用微藻生物固碳法减排 CO2正成为研究热点。本文以普通小球藻(Chlorella vulgaris,FACHB-1227)为研究对象,采用SE无碳培养基,在沿程曝气型套管式光生物反应器中通入含不同体积分数 CO2(5%、10%、15%和20%)的模拟烟气培养小球藻,培养周期为17天,以细胞密度和平均固碳速率为检测指标,研究模拟烟气下普通小球藻生长情况及固碳能力。实验结果表明:当模拟烟气中CO2体积分数为10%时,普通小球藻的细胞密度达到最大值8.76×106cells/mL,相比于5%组、15%组和20%组分别提高了54.23%、66.86%和76.97%;其平均固碳速率达最大值30.18mg/(L·d),较5%组、15%组和20%组分别提高了57.27%、70.89%和81.91%。可见,在模拟烟气中CO

  2. Reusable amine-based structural motifs for green house gas (CO2) fixation.

    Science.gov (United States)

    Dalapati, Sasanka; Jana, Sankar; Saha, Rajat; Alam, Md Akhtarul; Guchhait, Nikhil

    2012-07-01

    A series of compounds with an amine based structural motif (ASM) have been synthesized for efficient atmospheric CO(2) fixation. The H-bonded ASM-bicarbonate complexes were formed with an in situ generated HCO(3)(-) ion. The complexes have been characterized by IR, (13)C NMR, and X-ray single-crystal structural analysis. ASM-bicarbonate salts have been converted to pure ASMs in quantitative yield under mild conditions for recycling processes.

  3. Characterization of Polymeric Chemiresistors for Gas Sensor

    Directory of Open Access Journals (Sweden)

    Hendro Juwono

    2012-06-01

    Full Text Available Composite polymer-carbon has resistance change if come into contact with gas. Composite polymer-carbon can be used as a gas sensor. This research will be characterized the sensor composite polymer-carbon that has been made from 6 types of polymer, which are; PEG6000, PEG20M, PEG200, PEG1540, Silicon and Squelene. The 6 sensors will be tested by 9 types of gas, which are; Aceton, Aceton Nitril, Benzene, Etanol, Methanol, Ethyl Aceton, Chloroform, n-Hexan and Toluene. This characterization will be grouped into 4 claster of characteristics, which are; the selectivity (influence type of gas, the sensitivity (influence volume of gas, the influence of temperature and the influence of humidity. Test using method testing sensors that paleced in an isolated chamber which is connected with data acquisition. variations of temperature, humidity, type and volume of gas will be condition in the chamber. Correspondence analysis and regression will be used to process the data. Test results found that each sensor of type of polymers have different sensitivity and selectivity towards a particular type of gas. Resistance sensors increases with rising temperature and humidity environment with a polynomial equation of order-2 and order-3

  4. Near-IR telecommunication diode laser based double-pass QEPAS sensor for atmospheric CO2 detection

    Science.gov (United States)

    Zheng, H.; Dong, L.; Liu, X.; Liu, Y.; Wu, H.; Ma, W.; Zhang, L.; Yin, W.; Jia, S.

    2015-12-01

    A novel double pass quartz enhanced photoacoustic spectroscopy (QEPAS) sensor for atmospheric CO2 detection is developed by use of a 1.5 μm telecommunication diode laser. A low-cost high-reflection concave mirror is positioned behind a traditional QEPAS based acoustic detection module to enhance the absorption optical path and improve the detection sensitivity. The obtained minimum detection limit is 29 ppmV for 1 s averaging time which corresponds to a normalized noise equivalent absorption coefficient (NNEA, 1σ) of 2.\\text{2}× {{10}-9} \\text{c}{{\\text{m}}-1}\\centerdot \\text{W}\\centerdot \\text{H}{{\\text{z}}-\\frac{1{2}}} . With a 247 s averaging time, it demonstrates an ultimate detectable sensitivity of 1.74 ppmV.

  5. Improved method for measuring the apparent CO2 photocompensation point resolves the impact of multiple internal conductances to CO2 to net gas exchange.

    Science.gov (United States)

    Walker, Berkley J; Ort, Donald R

    2015-11-01

    There is a growing interest in accurate and comparable measurements of the CO2 photocompensation point (Γ*), a vital parameter to model leaf photosynthesis. The Γ* is measured as the common intersection of several CO2 response curves, but this method may incorrectly estimate Γ* by using linear fits to extrapolate curvilinear responses and single conductances to convert intercellular photocompensation points (Ci *) to chloroplastic Γ*. To determine the magnitude and minimize the impact of these artefacts on Γ* determinations, we used a combination of meta-analysis, modelling and original measurements to develop a framework to accurately determine Ci *. Our modelling indicated that the impact of using linear fits could be minimized based on the measurement CO2 range. We also propose a novel method of analysing common intersection measurements using slope-intercept regression. Our modelling indicated that slope-intercept regression is a robust analytical tool that can help determine if a measurement is biased because of multiple internal conductances to CO2 . Application of slope-intercept regression to Nicotiana tabacum and Glycine max revealed that multiple conductances likely have little impact to Ci * measurements in these species. These findings present a robust and easy to apply protocol to help resolve key questions concerning CO2 conductance through leaves.

  6. Thermodynamic and Process Modelling of Gas Hydrate Systems in CO2 Capture Processes

    DEFF Research Database (Denmark)

    Herslund, Peter Jørgensen

    A novel gas separation technique based on gas hydrate formation (solid precipitation) is investigated by means of thermodynamic modeling and experimental investigations. This process has previously been proposed for application in post-combustion carbon dioxide capture from power station flue gas...

  7. Airborne Multi-Gas Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes to develop an Airborne Multi-Gas Sensor (AMUGS) based upon two-tone, frequency modulation spectroscopy (TT-FMS). Mesa Photonics has developed...

  8. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture - Part A: Methodology and reference cases

    Science.gov (United States)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

    2016-08-01

    Driven by the search for the highest theoretical efficiency, in the latest years several studies investigated the integration of high temperature fuel cells in natural gas fired power plants, where fuel cells are integrated with simple or modified Brayton cycles and/or with additional bottoming cycles, and CO2 can be separated via chemical or physical separation, oxy-combustion and cryogenic methods. Focusing on Solid Oxide Fuel Cells (SOFC) and following a comprehensive review and analysis of possible plant configurations, this work investigates their theoretical potential efficiency and proposes two ultra-high efficiency plant configurations based on advanced intermediate-temperature SOFCs integrated with a steam turbine or gas turbine cycle. The SOFC works at atmospheric or pressurized conditions and the resulting power plant exceeds 78% LHV efficiency without CO2 capture (as discussed in part A of the work) and 70% LHV efficiency with substantial CO2 capture (part B). The power plants are simulated at the 100 MW scale with a complete set of realistic assumptions about fuel cell (FC) performance, plant components and auxiliaries, presenting detailed energy and material balances together with a second law analysis.

  9. Magnesium hydroxide extracted from a magnesium-rich mineral for CO2 sequestration in a gas-solid system.

    Science.gov (United States)

    Lin, Pao-Chung; Huang, Cheng-Wei; Hsiao, Ching-Ta; Teng, Hsisheng

    2008-04-15

    Magnesium hydroxide extracted from magnesium-bearing minerals is considered a promising agent for binding CO2 as a carbonate mineral in a gas-solid reaction. An efficient extraction route consisting of hydrothermal treatment on serpentine in HCl followed by NaOH titration for Mg(OH)2 precipitation was demonstrated. The extracted Mg(OH)2 powder had a mean crystal domain size as small as 12 nm and an apparent surface area of 54 m2/g. Under one atmosphere of 10 vol% CO2/N2, carbonation of the serpentine-derived Mg(OH)2 to 26% of the stoichiometric limit was achieved at 325 degrees C in 2 h; while carbonation of a commercially available Mg(OH)2, with a mean crystal domain size of 33 nm and an apparent surface area of 3.5 m2/g, reached only 9% of the stoichiometric limit. The amount of CO2 fixation was found to be inversely proportional to the crystal domain size of the Mg(OH)2 specimens. The experimental data strongly suggested that only a monolayer of carbonates was formed on the crystal domain boundary in the gas-solid reaction, with little penetration of the carbonates into the crystal domain.

  10. Experimental investigation on fiber and CO2 inert gas fusion cutting of AZ31 magnesium alloy sheets

    Science.gov (United States)

    Scintilla, L. D.; Tricarico, L.

    2013-03-01

    The influence of processing parameters and laser source type on cutting edge quality of AZ31 magnesium alloy sheets and differences in cutting efficiency between fiber and CO2 lasers were studied. A first part of the cutting experiments compared a fiber and CO2 laser source when cutting 1 mm thick sheets in continuous wave mode and using Argon as an assist gas. The effects of cutting speed and assist gas pressure were investigated and optimal conditions were identified. In the second part of the experimental investigation, 3.3 mm thick sheets were cut using fiber laser. Focal position and cutting speed were varied in order to detect the optimal combination of processing parameters to obtain the best edge quality. For both sheet thicknesses investigated, surface roughness, dross height, and striation pattern inclination were measured. Cutting quality assessment and classification was carried out according to UNI EN ISO 9013 standard. Results showed that productivity, process efficiency and cutting edges quality obtained using fiber lasers outperform CO2 laser performances and therefore are considered suitable for application like sheet metal trimming.

  11. Selective extraction of CO2 from simulated flue gas using polymeric ionic liquid sorbent coatings in solid-phase microextraction gas chromatography.

    Science.gov (United States)

    Zhao, Qichao; Anderson, Jared L

    2010-07-02

    The CO2 selectivity of two polymeric task-specific ionic liquid sorbent coatings, poly(1-vinyl-3-hexylimidazolium) bis[(trifluoromethyl)sulfonyl]imide [poly(VHIM-NTf2)] and poly(1-vinyl-3-hexylimidazolium) taurate [poly(VHIM-taurate)], was examined using solid-phase microextraction (SPME) for the determination of CO2 in simulated flue gas. For comparison purposes, a commercial SPME fiber, Carboxen-PDMS, was also studied. A study into the effect of humidity revealed that the poly(VHIM-taurate) fiber exhibited enhanced resistance to water, presumably due to the unique mechanism of CO2 capture. The effect of temperature on the performance of the PIL-based and Carboxen fibers was examined by generating calibration curves under various temperatures. The sensitivity, linearity, and linear range of the three fibers were evaluated. The extraction of CH4 and N2 was performed and the selectivities of the PIL-based and Carboxen fibers were compared. The poly(VHIM-NTf2) fiber was found to possess superior CO2/CH4 and CO2/N2 selectivities compared to the Carboxen fiber, despite the smaller film thicknesses of the PIL-based fibers. A scanning electron microscopy study suggests that the amine group of the poly(VHIM-taurate) is capable of selectively reacting with CO2 but not CH4 or N2, resulting in a significant surface morphology change of the sorbent coating.

  12. CO2 Gas Shielded Welding for Martensitic Stainless Steel%马氏体不锈钢的CO2气体保护焊

    Institute of Scientific and Technical Information of China (English)

    陈婵娟

    2012-01-01

    分析了马氏体不锈钢CO2气体保护焊的焊接特点,基于其焊接冷裂纹、残余内应力、焊接后组织发生改变等问题,介绍了马氏体不锈钢CO2气体保护焊的焊接工艺要点,通过这些措施可以很好地解决上述问题,保障焊接质量.

  13. Selective Reversible Absorption of the Industrial Off-Gas Components CO2 and NOx by Ionic Liquids

    DEFF Research Database (Denmark)

    Kaas-Larsen, Peter Kjartan; Thomassen, Peter; Schill, Leonard;

    2016-01-01

    Ionic liquids are promising new materials for climate and pollution control by selective absorption of CO2 and NOx in industrial off-gases. In addition pratical cleaning of industrial off gases seems to be attractive by use of ionic liquids distributed on the surface of porous, high surface area...... carriers in the form of so-called Supported Ionic Liquid Phase (SILP) materials. The potential of selected ionic liquids for absorption of CO2 and NOx will be demonstrated and the possible mechanism of absortion will be described on the molecular level. Our vision of application of these ionic liquids...... in the form of SILP filters to flue gas cleaning in power plants, waste incineration plants, cement and glass factories as well as unborad ships will be adressed....

  14. Reduction of CO2 emissions from road transport in cities impact of dynamic route guidance system on greenhouse gas emission

    CERN Document Server

    Markiewicz, Michal

    2017-01-01

    Michal Markiewicz presents the outcomes of his research regarding the influence of dynamic route guidance system on overall emission of carbon dioxide from road transport in rural areas. Sustainable transportation in smart cities is a big challenge of our time, but before electric vehicles replace vehicles that burn fossil fuels we have to think about traffic optimization methods that reduce the amount of greenhouse gas emissions. Contents Comparison of Travel Time Measurements Using Floating Car Data and Intelligent Infrastructure Integration of Cellular Automata Traffic Simulator with CO2 Emission Model Impact of Dynamic Route Guidance System on CO2 Emission Naxos Vehicular Traffic Simulator Target Groups Lecturers and students of computer science, transportation and logistics Traffic engineers The Author Dr. Michal Markiewicz defended his PhD thesis in computer science at the University of Bremen,TZI Technologie-Zentrum Informatik und Informationstechnik, Germany. Currently, he is working on commercializat...

  15. 基于胺法的旋流喷淋气液吸收烟气 CO2的性能%Performance of CO2 Capture from Flue Gas with Amines in Vortex Flow Spraying Scrubber

    Institute of Scientific and Technical Information of China (English)

    何书申; 赵兵涛; 俞致远

    2016-01-01

    A multistagw vortwx flow spraying scrubbwr was dwsignwd to wnhancw thw gas-liquid transfwr for CO2 capturw.Thw CO2 capturw wfficiwncy and mass transfwr cowfficiwnt of typical alcohol aminws (MEA and DEA)wwrw wxpwrimwntally invwstigatwd and thw wffwct of opwrating conditions on wfficiwncy was analyzwd.Thw rwsults show that thw wfficiwncy of CO2 capturw by MEA (maximum valuw 95%)is highwr than that by DEA (maximum valuw 92.3%)undwr thw samw wxpwrimwntal conditions.Thw comparison of thw rwsults with litwraturw data dwmonstratws that thw multistagw vortwx flow spraying scrubbwr wnhancws thw mass transfwr procwss of aminws-CO2 rwaction systwm. Thw CO2 rwmoval wfficiwncy incrwasws with thw incrwasw of thw mass fraction of aminws,liquid flow ratws and rwaction twmpwraturw.Thw lowwr CO2 inlwt volumw fraction and gas flow ratw arw bwnwficial to promotw CO2 rwmoval wfficiwncy.%为了强化 CO2捕集过程的气液传质,设计了一类多级旋流喷淋反应器,实验研究了典型的醇胺(乙醇胺(MEA)、二乙醇胺(DEA))脱除 CO2的分离效率和传质系数,并分析了操作条件的影响.结果表明:在相同的实验条件下,MEA 的脱碳效率(最大值95%)大于 DEA 的脱碳效率(最大值92.3%).与相关研究数据的对比表明,多级旋流喷淋可以有效增强醇胺-CO2喷淋反应系统的传质过程.醇胺溶液旋流气液吸收烟气 CO2的脱碳效率受操作条件的影响,其随着吸收剂质量分数、吸收剂流量和反应温度的增加而提高,随着烟气中 CO2体积分数和烟气流量的增加而降低.

  16. Modeling of Gas Diffusion in Ni/YSZ Electrodes in CO2 and Co-electrolysis

    DEFF Research Database (Denmark)

    Duhn, Jakob Dragsbæk; Jensen, Anker Degn; Wedel, Stig

    2017-01-01

    , pore diameter, current density, pitch and rib width has been investigated. It is shown that diffusion limitations on reactant/product transport may lead to carbon formation. The parameters describing the microstructure and the dimensions of the cathode channels and interconnect ribs are found to have...... a large effect on the carbon formation propensity. Given a set of parameters, a simple correlation between the CO mole fraction in the channel and under the interconnect rib, and current density during CO2-electrolysis can be derived. This correlation makes it possible to efficiently integrate...

  17. Amine-tethered adsorbents based on three-dimensional macroporous silica for CO(2) capture from simulated flue gas and air.

    Science.gov (United States)

    Liu, Fa-Qian; Wang, Lei; Huang, Zhao-Ge; Li, Chao-Qin; Li, Wei; Li, Rong-Xun; Li, Wei-Hua

    2014-03-26

    New covalently tethered CO2 adsorbents are synthesized through the in situ polymerization of N-carboxyanhydride (NCA) of l-alanine from amine-functionalized three-dimensional (3D) interconnected macroporous silica (MPS). The interconnected macropores provide low-resistant pathways for the diffusion of CO2 molecules, while the abundant mesopores ensure the high pore volume. The adsorbents exhibit high molecular weight (of up to 13058 Da), high amine loading (more than 10.98 mmol N g(-1)), fast CO2 capture kinetics (t1/2 CO2 g(-1) in simulated flue gas and 2.65 mmol CO2 g(-1) in simulated ambient air under 1 atm of dry CO2), as well as good stability over 120 adsorption-desorption cycles, which allows the overall CO2 capture process to be promising and sustainable.

  18. Bubble Clouds in Coastal Waters and Their Role in Air-Water Gas Exchange of CO2

    Directory of Open Access Journals (Sweden)

    Joseph R. Crosswell

    2015-08-01

    Full Text Available Bubbles generated by breaking waves can drive significant gas exchange between the ocean and atmosphere, but the role of bubble-mediated gas transfer in estuaries is unknown. Here, backscatter data from 41 acoustic Doppler current profiler stations was analyzed to assess subsurface bubble distributions in nine estuaries along the U.S. East and Gulf Coast. Wind speed, wind direction, and current velocity were the dominant controls on bubble entrainment, but the relative importance of these physical drivers depended on local geomorphology. Bubble entrainment in high-current or shallow, long-fetch estuaries began at wind speeds <5 m s−1. In deep or fetch-limited estuaries, bubble entrainment was less frequent and generally began at higher wind speeds. Data observed during several storms suggests that episodic bubble-driven gas exchange may be an important component of annual CO2 fluxes in large, shallow estuaries but would be less significant in other coastal systems.

  19. Research and Development of Solid-Electrolyte CO2 Sensor%固体电解质CO2传感器的研究与进展

    Institute of Scientific and Technical Information of China (English)

    全宝富; 何月华; 王彪; 梁喜双; 钟铁钢

    2007-01-01

    采用溶胶-凝胶法制备NASICON粉体材料,并利用XRD和IR对制得的材料进行表征.以NASICON粉体材料为基体,Li2CO3-BaCO3复合盐为敏感电极制作管式CO2气体传感器,并对其灵敏度、选择性和耐水性进行测量.在敏感电极中掺入质量分数为10%的SiO2,不仅明显改善器件的耐水性,而且使器件的初始稳定时间从30 min减小到5 min.

  20. Piezo-tolerant natural gas-producing microbes under accumulating pCO2

    NARCIS (Netherlands)

    Lindeboom, Ralph E.F.; Shin, Seung Gu; Weijma, Jan; Lier, van Jules B.; Plugge, Caroline M.

    2016-01-01

    Background: It is known that a part of natural gas is produced by biogenic degradation of organic matter, but the microbial pathways resulting in the formation of pressurized gas fields remain unknown. Autogeneration of biogas pressure of up to 20 bar has been shown to improve the quality of

  1. Piezo-tolerant natural gas-producing microbes under accumulating pCO2

    NARCIS (Netherlands)

    Lindeboom, Ralph E.F.; Shin, Seung Gu; Weijma, Jan; Lier, van Jules B.; Plugge, Caroline M.

    2016-01-01


    Background

    It is known that a part of natural gas is produced by biogenic degradation of organic matter, but the microbial pathways resulting in the formation of pressurized gas fields remain unknown. Autogeneration of biogas pressure of up to 20 bar has been shown to improve the quali

  2. EAF Gas Waste Heat Utilization and Discussion of the Energy Conservation and CO2 Emissions Reduction

    Science.gov (United States)

    Yang, Ling-zhi; Zhu, Rong; Ma, Guo-hong

    2016-02-01

    As a large number of energy was taken away by the high temperature furnace gas during the EAF smelting process, a huge economic and environmental benefits would obtained to recycle and utilize. In this paper, the energy of the EAF was analyzed theoretically with the hot metal ratio of 50%. Combined with the utilization of the gas waste heat during the scrap preheating, electricity generation, production of steam and production of coal gas processes, the effect of the energy saving and emission was calculated with comprehensive utilization of the high temperature furnace gas. An optimal scheme for utilization of the waste heat was proposed based on the calculation. The results show that the best way for energy saving and carbon reduction is the production of coal gas, while the optimal scheme for waste heat utilization is combined the production of coal gas with the scrap preheating, which will save 170 kWh/t of energy and decrease 57.88 kg/t of carbon emission. As hot metal ratio in EAF steelmaking is often more than 50%, which will produce more EAF gas waste heat, optimizing EAF gas waste heat utilization will have more obvious effect on energy saving and emission reduction.

  3. High resolution 12CO(2-1) observations of the molecular gas in Centaurus A

    NARCIS (Netherlands)

    Rydbeck, G.; Wiklind, T.; Cameron, M.; Wild, W.; Eckart, A.; Genzel, R.; Rothermel, H.

    1993-01-01

    Observations of (C-12)O(2-1) emission in the dust lane of Centaurus A show that, except for the center region, the overall distribution and kinematics of the molecular gas is consistent with that of ionized gas. Deconvolution of the observed emission reveals (i) a structure agreeing with what would

  4. Biological Effect of Gas Plasma Treatment on CO2 Gas Foaming/Salt Leaching Fabricated Porous Polycaprolactone Scaffolds in Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Tae-Yeong Bak

    2014-01-01

    Full Text Available Porous polycaprolactone (PCL scaffolds were fabricated by using the CO2 gas foaming/salt leaching process and then PCL scaffolds surface was treated by oxygen or nitrogen gas plasma in order to enhance the cell adhesion, spreading, and proliferation. The PCL and NaCl were mixed in the ratios of 3 : 1. The supercritical CO2 gas foaming process was carried out by solubilizing CO2 within samples at 50°C and 8 MPa for 6 hr and depressurization rate was 0.4 MPa/s. The oxygen or nitrogen plasma treated porous PCL scaffolds were prepared at discharge power 100 W and 10 mTorr for 60 s. The mean pore size of porous PCL scaffolds showed 427.89 μm. The gas plasma treated porous PCL scaffolds surface showed hydrophilic property and the enhanced adhesion and proliferation of MC3T3-E1 cells comparing to untreated porous PCL scaffolds. The PCL scaffolds produced from the gas foaming/salt leaching and plasma surface treatment are suitable for potential applications in bone tissue engineering.

  5. Integrated underground gas storage of CO2 and CH4 for renewable energy storage for a test case in China

    Science.gov (United States)

    Kühn, Michael; Li, Qi; Nakaten, Natalie, Christine; Kempka, Thomas

    2017-04-01

    Integration and further development of the energy supply system in China is a major challenge for the years to come. Part of the strategy is the implementation of a low carbon energy system based on carbon dioxide capture and storage (CCS). The innovative idea presented here is based on an extension of the power-to-gas-to-power (PGP) technology by establishing a closed carbon dioxide cycle [1]. Thereto, hydrogen generated from excess renewable energy is transformed into methane for combustion in a combined cycle gas power plant. To comply with the fluctuating energy demand, carbon dioxide produced during methane combustion and required for the methanation process as well as excess methane are temporarily stored in two underground reservoirs located close to each other [2]. Consequently, renewable energy generation units can be operated even if energy demand is below consumption, while stored energy can be fed into the grid as energy demand exceeds production [3]. We studied a show case for Xinjiang in China [4] to determine the energy demand of the entire process chain based on numerical computer simulations for the operation of the CO2 and CH4 storage reservoirs, and to ascertain the pressure regimes present in the storage formations during the injection and production phases of the annual cycle. [1] Streibel M., Nakaten N., Kempka T., Kühn M. (2013) Analysis of an integrated carbon cycle for storage of renewables. Energy Procedia 40, 202-211. doi: 10.1016/j.egypro.2013.08.024. [2] Kühn M., Streibel M., Nakaten N.C., Kempka T. (2014) Integrated Underground Gas Storage of CO2 and CH4 to Decarbonise the "Power-to-gas-to-gas-to-power" Technology. Energy Procedia 59, 9-15. doi: 10.1016/j.egypro.2014.10.342 [3] Kühn M., Nakaten N.C., Streibel M., Kempka T. (2014) CO2 Geological Storage and Utilization for a Carbon Neutral "Power-to-gas-to-power" Cycle to Even Out Fluctuations of Renewable Energy Provision. Energy Procedia 63, 8044-8049. doi: 10.1016/j.egypro.2014

  6. Gas Sensors Based on Electrodeposited Polymers

    Directory of Open Access Journals (Sweden)

    Boris Lakard

    2015-07-01

    Full Text Available Electrochemically deposited polymers, also called “synthetic metals”, have emerged as potential candidates for chemical sensing due to their interesting and tunable chemical, electrical, and structural properties. In particular, most of these polymers (including polypyrrole, polyaniline, polythiophene and their derivatives can be used as the sensitive layer of conductimetric gas sensors because of their conducting properties. An important advantage of polymer-based gas sensors is their efficiency at room temperature. This characteristic is interesting since most of the commercially-available sensors, usually based on metal oxides, work at high temperatures (300–400 °C. Consequently, polymer-based gas sensors are playing a growing role in the improvement of public health and environment control because they can lead to gas sensors operating with rapid detection, high sensitivity, small size, and specificity in atmospheric conditions. In this review, the recent advances in electrodeposited polymer-based gas sensors are summarized and discussed. It is shown that the sensing characteristics of electrodeposited polymers can be improved by chemical functionalization, nanostructuration, or mixing with other functional materials to form composites or hybrid materials.

  7. Biomass Steam Gasification with In-Situ CO2 Capture for Enriched Hydrogen Gas Production: A Reaction Kinetics Modelling Approach

    Directory of Open Access Journals (Sweden)

    Mohamed Ibrahim Abdul Mutalib

    2010-08-01

    Full Text Available Due to energy and environmental issues, hydrogen has become a more attractive clean fuel. Furthermore, there is high interest in producing hydrogen from biomass with a view to sustainability. The thermochemical process for hydrogen production, i.e. gasification, is the focus of this work. This paper discusses the mathematical modeling of hydrogen production process via biomass steam gasification with calcium oxide as sorbent in a gasifier. A modelling framework consisting of kinetics models for char gasification, methanation, Boudouard, methane reforming, water gas shift and carbonation reactions to represent the gasification and CO2 adsorption in the gasifier, is developed and implemented in MATLAB. The scope of the work includes an investigation of the influence of the temperature, steam/biomass ratio and sorbent/biomass ratio on the amount of hydrogen produced, product gas compositions and carbon conversion. The importance of different reactions involved in the process is also discussed. It is observed that hydrogen production and carbon conversion increase with increasing temperature and steam/biomass ratio. The model predicts a maximum hydrogen mole fraction in the product gas of 0.81 occurring at 950 K, steam/biomass ratio of 3.0 and sorbent/biomass ratio of 1.0. In addition, at sorbent/biomass ratio of 1.52, purity of H2 can be increased to 0.98 mole fraction with all CO2 present in the system adsorbed.

  8. CO2 + N2O mixture gas hydrate formation kinetics and effect of soil minerals on mixture-gas hydrate formation process

    Science.gov (United States)

    Enkh-Amgalan, T.; Kyung, D.; Lee, W.

    2012-12-01

    CO2 mitigation is one of the most pressing global scientific topics in last 30 years. Nitrous oxide (N2O) is one of the main greenhouse gases (GHGs) defined by the Kyoto Protocol and its global warming potential (GWP) of one metric ton is equivalent to 310 metric tons of CO2. They have similar physical and chemical properties and therefore, mixture-gas (50% CO2 + 50% N2O) hydrate formation process was studied experimentally and computationally. There were no significant research to reduce N20 gas and we tried to make hydrate to mitigate N20 and CO2 in same time. Mixture gas hydrate formation periods were approximately two times faster than pure N2O hydrate formation kinetic in general. The fastest induction time of mixture-gas hydrate formation observed in Illite and Quartz among various soil mineral suspensions. It was also observed that hydrate formation kinetic was faster with clay mineral suspensions such as Nontronite, Sphalerite and Montmorillonite. Temperature and pressure change were not significant on hydrate formation kinetic; however, induction time can be significantly affected by various chemical species forming under the different suspension pHs. The distribution of chemical species in each mineral suspension was estimated by a chemical equilibrium model, PHREEQC, and used for the identification of hydrate formation characteristics in the suspensions. With the experimental limitations, a study on the molecular scale modeling has a great importance for the prediction of phase behavior of the gas hydrates. We have also performed molecular dynamics computer simulations on N2O and CO2 hydrate structures to estimate the residual free energy of two-phase (hydrate cage and guest molecule) at three different temperature ranges of 260K, 273K, and 280K. The calculation result implies that N2O hydrates are thermodynamically stable at real-world gas hydrate existing condition within given temperature and pressure. This phenomenon proves that mixture-gas could be

  9. 油气管道CO2/H2 S腐蚀及防护技术研究进展%Research Progress of CO2/H2 S Corrosion in Oil and Gas Pipelines and the Protection Techniques

    Institute of Scientific and Technical Information of China (English)

    王丹; 袁世娇; 吴小卫; 谢飞; 赵启慧; 杨帆; 程贵鑫

    2016-01-01

    CO2和H2 S是油气管道中主要的腐蚀介质,两者往往同时存在于原油和天然气之中,是造成油气输送管道内腐蚀发生的主要原因之一,甚至会导致管道失效、穿孔、泄漏、开裂等现象,严重威胁了管网的安全运行及正常生产。因此CO2和H2 S引起的管道腐蚀问题,已成为当前研究的热点问题。针对油气管道日益严重的CO2和H2 S腐蚀问题,综述了CO2单独存在、H2 S单独存在以及CO2和H2 S共同存在三种体系中油气管道的腐蚀过程,得出了在这三种腐蚀体系下油气管道出现的主要腐蚀行为规律以及腐蚀机理。阐述了CO2和H2 S共同存在体系下,缓蚀剂、耐蚀性管材、电化学防腐技术、管道内涂层技术等先进的油气管道腐蚀防护技术,并剖析了这些防护措施各自的特点及在实际工程使用中的优势和局限性。最后,展望了CO2和H2 S共存体系的进一步研究方向以及更经济、更有效的防腐措施发展前景。%ABSTRACT:CO2 and H2 S are the major corrosion media in oil and gas pipeline, often existing in both crude oil and natural gas. Their presence is one of the main causes for internal corrosion in oil and gas pipelines, and even leads to pipeline failure, perfora-tions, leaks and cracks. It′s a serious threat to the safe operation of the pipeline network and normal production. So pipeline corro-sion problems caused by CO2 and H2 S have become a hot issue of current research. For the growing oil and gas pipeline corrosion problems caused by CO2 and H2 S, the corrosion behaviors of oil and gas pipelines in CO2 alone, H2 S alone and the co-existence of CO2 and H2 S system were systematically compared in this paper. The law and mechanism of pipeline corrosion behavior in these three corrosion systems were obtained. And the protection techniques against oil and gas pipeline corrosion were listed, such as cor-rosion inhibitors, corrosion resistant pipes

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

    Directory of Open Access Journals (Sweden)

    Thorsten Graunke

    2016-01-01

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

  11. Metal Oxide Semi-Conductor Gas Sensors in Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    George F. Fine

    2010-06-01

    Full Text Available Metal oxide semiconductor gas sensors are utilised in a variety of different roles and industries. They are relatively inexpensive compared to other sensing technologies, robust, lightweight, long lasting and benefit from high material sensitivity and quick response times. They have been used extensively to measure and monitor trace amounts of environmentally important gases such as carbon monoxide and nitrogen dioxide. In this review the nature of the gas response and how it is fundamentally linked to surface structure is explored. Synthetic routes to metal oxide semiconductor gas sensors are also discussed and related to their affect on surface structure. An overview of important contributions and recent advances are discussed for the use of metal oxide semiconductor sensors for the detection of a variety of gases—CO, NOx, NH3 and the particularly challenging case of CO2. Finally a description of recent advances in work completed at University College London is presented including the use of selective zeolites layers, new perovskite type materials and an innovative chemical vapour deposition approach to film deposition.

  12. A Rapid Process for Fabricating Gas Sensors

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2014-07-01

    Full Text Available Zinc oxide (ZnO is a low-toxicity and environmentally-friendly material applied on devices, sensors or actuators for “green” usage. A porous ZnO film deposited by a rapid process of aerosol deposition (AD was employed as the gas-sensitive material in a CO gas sensor to reduce both manufacturing cost and time, and to further extend the AD application for a large-scale production. The relative resistance change (△R/R of the ZnO gas sensor was used for gas measurement. The fabricated ZnO gas sensors were measured with operating temperatures ranging from 110 °C to 180 °C, and CO concentrations ranging from 100 ppm to 1000 ppm. The sensitivity and the response time presented good performance at increasing operating temperatures and CO concentrations. AD was successfully for applied for making ZnO gas sensors with great potential for achieving high deposition rates at low deposition temperatures, large-scale production and low cost.

  13. First Fifty Years of Chemoresistive Gas Sensors

    Directory of Open Access Journals (Sweden)

    Giovanni Neri

    2015-01-01

    Full Text Available The first fifty years of chemoresistive sensors for gas detection are here reviewed, focusing on the main scientific and technological innovations that have occurred in the field over the course of these years. A look at advances made in fundamental and applied research and leading to the development of actual high performance chemoresistive devices is presented. The approaches devoted to the synthesis of novel semiconducting materials with unprecedented nanostructure and gas-sensing properties have been also presented. Perspectives on new technologies and future applications of chemoresistive gas sensors have also been highlighted.

  14. Hollow fibers for compact infrared gas sensors

    Science.gov (United States)

    Lambrecht, A.; Hartwig, S.; Herbst, J.; Wöllenstein, J.

    2008-02-01

    Hollow fibers can be used for compact infrared gas sensors. The guided light is absorbed by the gas introduced into the hollow core. High sensitivity and a very small sampling volume can be achieved depending on fiber parameters i.e. attenuation, flexibility, and gas exchange rates. Different types of infrared hollow fibers including photonic bandgap fibers were characterized using quantum cascade lasers and thermal radiation sources. Obtained data are compared with available product specifications. Measurements with a compact fiber based ethanol sensor are compared with a system simulation. First results on the detection of trace amounts of the explosive material TATP using hollow fibers and QCL will be shown.

  15. Hydrogeological investigations for mineral water and CO2 gas in the village of Bac, Bitola, The Republic of Macedonia

    OpenAIRE

    2005-01-01

    Tree exploration drill holes were dug in the Neogene Middle Pliocene sediments in the vicinity of the village of Bac for the investigation of the mineral water and CO2 gas. The first drill hole (B 1) was dug 30 m in depth indicated a water bearing horizon in o to 26.4 m thick grey marly sandstone with a free level aquifer and ground water 2.2 m at depth and yield of 10l/s. The second and third drill holes (ED-1 and ED-2) were dug 301 m to depth and determined a free level aquifer, a sub ar...

  16. CO2, CO, and CH4 measurements from tall towers in the NOAA Earth System Research Laboratory's Global Greenhouse Gas Reference Network: instrumentation, uncertainty analysis, and recommendations for future high-accuracy greenhouse gas monitoring efforts

    Science.gov (United States)

    Andrews, A. E.; Kofler, J. D.; Trudeau, M. E.; Williams, J. C.; Neff, D. H.; Masarie, K. A.; Chao, D. Y.; Kitzis, D. R.; Novelli, P. C.; Zhao, C. L.; Dlugokencky, E. J.; Lang, P. M.; Crotwell, M. J.; Fischer, M. L.; Parker, M. J.; Lee, J. T.; Baumann, D. D.; Desai, A. R.; Stanier, C. O.; De Wekker, S. F. J.; Wolfe, D. E.; Munger, J. W.; Tans, P. P.

    2014-02-01

    A reliable and precise in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Global Greenhouse Gas Reference Network. The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary-layer trace-gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2, 6 ppb for CO, and 0.5 ppb for CH4, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures, and flow rates, that are inputs for automated alerts and quality control algorithms. Detailed and time-dependent uncertainty estimates have been constructed for all of the gases, and the uncertainty framework could be readily adapted to other species or analysis systems. The design emphasizes use of off-the-shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high-accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.

  17. CO2, CO and CH4 measurements from the NOAA Earth System Research Laboratory's Tall Tower Greenhouse Gas Observing Network: instrumentation, uncertainty analysis and recommendations for future high-accuracy greenhouse gas monitoring efforts

    Science.gov (United States)

    Andrews, A. E.; Kofler, J. D.; Trudeau, M. E.; Williams, J. C.; Neff, D. H.; Masarie, K. A.; Chao, D. Y.; Kitzis, D. R.; Novelli, P. C.; Zhao, C. L.; Dlugokencky, E. J.; Lang, P. M.; Crotwell, M. J.; Fischer, M. L.; Parker, M. J.; Lee, J. T.; Baumann, D. D.; Desai, A. R.; Stanier, C. O.; de Wekker, S. F. J.; Wolfe, D. E.; Munger, J. W.; Tans, P. P.

    2013-02-01

    A robust in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Tall Tower Greenhouse Gas Observing Network. The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary layer trace gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2, 6 ppb for CO, and 0.5 ppb for CH4, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures and flow rates that are inputs for automated alerts and quality control algorithms. These algorithms provide detailed and time-dependent uncertainty estimates for all of the gases and could be adapted to other species or analysis systems. The design emphasizes use of off the shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.

  18. CO2气体等焓膨胀的焦耳-汤姆逊效应%Joule-Thomson Effect of CO2 Gas Isenthalpic Expansion

    Institute of Scientific and Technical Information of China (English)

    莫小梅

    2010-01-01

    运用van der Waals状态方程讨论焦汤系数和转换温度,通过对CO2实际气体等焓膨胀的焦汤系数及转换温度与van der Waals理论值比较发现,CO2实际气体的焦汤系和转换温度与理论值偏差不大,基本能反映实际气体的焦耳-汤姆逊的各种基本关系,可应用于一般热力学的定性分析.

  19. CO2 and H2S gas injection heavy oil field

    Energy Technology Data Exchange (ETDEWEB)

    Padua, K.G.O. [Petrobras (Canada)

    2011-07-01

    Heavy oils constitute one of the largest fossil fuel reserves on earth; among them there are naturally fractured carbonate reservoirs under bottomwater. Those reservoirs are composed of sour heavy oil and its recovery is difficult, miscible processes are expensive and thermal methods are inefficient due to the harsh conditions. The aim of this paper is to investigate the use of injection of carbon dioxide and hydrogen sulfide mixtures. Fluid and reservoir characterizations were conducted using published observations, dynamic modeling and a comparative study. Reservoir performance under natural depletion and immiscible gas injection with effluent gas were then analyzed and compared. Expected breakthrough and composition of the produced fluid were presented in this study to provide the input necessary for operational planning. This paper presented a comparison between reservoir performance under natural depletion and immiscible gas injection, providing qualitative information to evaluate an effluent gas project.

  20. Hynol: An economic process for methanol production from biomass and natural gas with reduced CO2 emission

    Science.gov (United States)

    Steinberg, M.; Dong, Yuanji

    1993-10-01

    The Hynol process is proposed to meet the demand for an economical process for methanol production with reduced CO2 emission. This new process consists of three reaction steps: (1) hydrogasification of biomass, (2) steam reforming of the produced gas with additional natural gas feedstock, and (3) methanol synthesis of the hydrogen and carbon monoxide produced during the previous two steps. The H2-rich gas remaining after methanol synthesis is recycled to gasify the biomass in an energy neutral reactor so that there is no need for an expensive oxygen plant as required by commercial steam gasifiers. Recycling gas allows the methanol synthesis reactor to perform at a relatively lower pressure than conventional while the plant still maintains high methanol yield. Energy recovery designed into the process minimizes heat loss and increases the process thermal efficiency. If the Hynol methanol is used as an alternative and more efficient automotive fuel, an overall 41% reduction in CO2 emission can be achieved compared to the use of conventional gasoline fuel. A preliminary economic estimate shows that the total capital investment for a Hynol plant is 40% lower than that for a conventional biomass gasification plant. The methanol production cost is $0.43/gal for a 1085 million gal/yr Hynol plant which is competitive with current U.S. methanol and equivalent gasoline prices. Process flowsheet and simulation data using biomass and natural gas as cofeedstocks are presented. The Hynol process can convert any condensed carbonaceous material, especially municipal solid waste (MSW), to produce methanol.

  1. Rhombohedral calcite precipitation from CO2-H2O-Ca(OH)2 slurry under supercritical and gas CO2 media

    CERN Document Server

    Montes-Hernandez, German; Geoffroy, Nicolas; Charlet, Laurent; Pironon, Jacques

    2008-01-01

    The formation of solid calcium carbonate (CaCO3) from aqueous solutions or slurries containing calcium and carbon dioxide (CO2) is a complex process of considerable importance in the ecological, geochemical and biological areas. Moreover, the demand for powdered CaCO3 has increased considerably recently in various fields of industry. The aim of this study was therefore to synthesize fine particles of calcite with controlled morphology by hydrothermal carbonation of calcium hydroxide at high CO2 pressure (initial PCO2=55 bar) and at moderate and high temperature (30 and 90 degrees C). The morphology of precipitated particles was identified by transmission electron microscopy (TEM/EDS) and scanning electron microscopy (SEM/EDS). In addition, an X-ray diffraction analysis was performed to investigate the carbonation efficiency and purity of the solid product. Carbonation of dispersed calcium hydroxide in the presence of supercritical (PT=90 bar, T=90 degrees C) or gaseous (PT=55 bar, T=30 degrees C) CO2 led to t...

  2. Fabrication and characterization of nano-gas sensor arrays

    Science.gov (United States)

    Hassan, H. S.; Kashyout, A. B.; Morsi, I.; Nasser, A. A. A.; Raafat, A.

    2015-03-01

    A novel structures of Nanomaterials gas sensors array constructed using ZnO, and ZnO doped with Al via sol-gel technique. Two structure arrays are developed; the first one is a double sensor array based on doping with percentages of 1% and 5%. The second is a quadrature sensor array based on several doping ratios concentrations (0%, 1%, 5% and 10%). The morphological structures of prepared ZnO were revealed using scanning electron microscope (SEM). X-ray diffraction (XRD) patterns reveal a highly crystallized wurtzite structure and used for identifying phase structure and chemical state of both ZnO and ZnO doped with Al under different preparation conditions and different doping ratios. Chemical composition of Al-doped ZnO nanopowders was performed using energy dispersive x-ray (EDS) analysis. The electrical characteristics of the sensor are determined by measuring the two terminal sensor's output resistance for O2, H2 and CO2 gases as a function of temperature.

  3. Mass-spectrometric determination of O2 and CO 2 gas exchange in illuminated higher-plant cells : Evidence for light-inhibition of substrate decarboxylations.

    Science.gov (United States)

    Avelange, M H; Thiéry, J M; Sarrey, F; Gans, P; Rébeillé, F

    1991-01-01

    In order to estimate photosynthetic and respiratory rates in illuminated photoautotrophic cells of carnation (Dianthus caryophyllus L.), simultaneous measurements of CO2 and O2 gas exchange were performed using (18)O2, (13)CO2 and a mass-spectrometry technique. This method allowed the determination, and thus the comparison, of unidirectional fluxes of O2 and CO2. In optimum photosynthetic conditions (i.e. in the presence of high light and a saturating level of CO2), the rate of CO2 influx represented 75±5% of the rate of gross O2 evolution. After a dark-to-light transition, the rate of CO2 efflux was inhibited by 50% whereas the O2-uptake rate was little affected. The effect of a recycling of respiratory CO2 through photosynthesis on the exchange of CO2 gas was investigated using a mathematical model. The confliction of the experimental data with the simulated gas-exchange rates strongly supported the view that CO2 recycling was a minor event in these cells and could not be responsible for the observed inhibition of CO2 efflux. On the basis of this assumption it was concluded that illumination of carnation cells resulted in a decrease of substrate decarboxylations, and that CO2 efflux and O2 uptake were not as tightly coupled in the light as in the dark. Furthermore, it could be calculated from the rate of gross photosynthesis that the chloroplastic electron-transport chain produced enough ATP in the light to account for the measured CO2-uptake rate without involving cyclic transfer of electrons around PS I or mitochondrial supplementation.

  4. Research on Mechanism of Deformation Reduced by CO2 Gas Shielded Arc Welding%CO2气体保护焊降低焊接变形机理研究

    Institute of Scientific and Technical Information of China (English)

    李汉文; 宗培; 杨铁磊

    2011-01-01

    为了研究CO2气体保护焊强制对流对焊接变形的影响,通过分析多种换热边界条件,分别确定了适用于自然对流和有强制对流效果的气体保护焊的对流辐射边界条件计算公式,计算得出综合换热系数.在此基础上对手工焊和CO2焊焊接应力应变进行计算分析.结果表明,CO2焊保护气体形成的强制对流而形成的冷却环境是其降低焊接变形的重要因素.%The influences of forced convection on the welding deformation of CO2 gas shielded arc welding were investigated. The formula of the combined coefficient, including convection coefficient and radiation coefficient, was obtained by analyzing two convection boundary conditions, which considers natrual convection and force convection, seperately. Based on these two conditions, the deformation of butt welding plate with 3 mm was simulated. The stimulation results show that compared with manual welding, the force convection boundary condition of CO2 gas shielded arc welding is a critical factor to form less deformation.

  5. Detection of CO2 leakage by the surface-soil CO2-concentration monitoring (SCM) system in a small scale CO2 release test

    Science.gov (United States)

    Chae, Gitak; Yu, Soonyoung; Sung, Ki-Sung; Choi, Byoung-Young; Park, Jinyoung; Han, Raehee; Kim, Jeong-Chan; Park, Kwon Gyu

    2015-04-01

    Monitoring of CO2 release through the ground surface is essential to testify the safety of CO2 storage projects. We conducted a feasibility study of the multi-channel surface-soil CO2-concentration monitoring (SCM) system as a soil CO2 monitoring tool with a small scale injection. In the system, chambers are attached onto the ground surface, and NDIR sensors installed in each chamber detect CO2 in soil gas released through the soil surface. Before injection, the background CO2 concentrations were measured. They showed the distinct diurnal variation, and were positively related with relative humidity, but negatively with temperature. The negative relation of CO2 measurements with temperature and the low CO2 concentrations during the day imply that CO2 depends on respiration. The daily variation of CO2 concentrations was damped with precipitation, which can be explained by dissolution of CO2 and gas release out of pores through the ground surface with recharge. For the injection test, 4.2 kg of CO2 was injected 1 m below the ground for about 30 minutes. In result, CO2 concentrations increased in all five chambers, which were located less than 2.5 m of distance from an injection point. The Chamber 1, which is closest to the injection point, showed the largest increase of CO2 concentrations; while Chamber 2, 3, and 4 showed the peak which is 2 times higher than the average of background CO2. The CO2 concentrations increased back after decreasing from the peak around 4 hours after the injection ended in Chamber 2, 4, and 5, which indicated that CO2 concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data in Chamber 2 and 5, which had low increase rates in the CO2 injection test, were used for statistical analysis. The result shows that the coefficient of variation (CV) of CO2 measurements for 30 minutes is efficient to determine a leakage signal, with reflecting the abnormal change in CO2

  6. Ultra-Low-Power MEMS Selective Gas Sensors

    Science.gov (United States)

    Stetter, Joseph

    2012-01-01

    This innovation is a system for gas sensing that includes an ultra-low-power MEMS (microelectromechanical system) gas sensor, combined with unique electronic circuitry and a proprietary algorithm for operating the sensor. The electronics were created from scratch, and represent a novel design capable of low-power operation of the proprietary MEMS gas sensor platform. The algorithm is used to identify a specific target gas in a gas mixture, making the sensor selective to that target gas.

  7. Carbon Nanotube Gas Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sensing gas molecules is critical to environmental monitoring, control of chemical processes, space missions as well as agricultural and medical applications....

  8. Multi-technique monitoring of CO2 leakage from an engineered CO2 leakage experiment

    Science.gov (United States)

    Zhou, X.; Apple, M. E.; Dobeck, L.; Cunningham, A. B.; Spangler, L.

    2012-12-01

    Monitoring of canopy and soil geophysical and geochemical properties in vadose zone by multiple techniques were carried out from 1999 to 2012 using an engineered CO2 release to simulate the CO2 leakage from CO2 storage at an agricultural plot at Bozeman, MT. The CO2 release was based on a horizontally-drilled well of 100 m at a depth of about 2.0-2.3m (Fig.1). Techniques utilized include hyperspectral and infrared radiation of various vegetations, electric conductivity in soil, magnetic field at the ground surface, and soil gas composition and dynamics using various gas sensors and soil moisture sensors. Measurements were made at several sites along a transect perpendicular to the releasing well, along which the soil CO2 concentration attenuated from high to normal condition at control site. The response of the canopy hyperspectral reflectance, infrared radiation, soil geophysical properties such as soil electric conductivity, top soil magnetic susceptibility and magnetic field, soil gas composition such as CO2 and O2 concentration to CO2 release at different rates were quantified and will be shown at this presentation. Fig.2 shows some examples of the results. The different responses at the impact and control sites are used to assess the effectiveness for CO2 surface and near-surface detection when a possible CO2 leakage occurs.ig.1. A schematic showing the injection and release of CO2 at an agricultral plot in Bozeman, MT. ig.2. Some examples of results showing the response of vegetation, hyperspectral reflectance, soil electric conductivity, soil O2 concentration to the release of CO2.

  9. Supercritical CO2 direct cycle Gas Fast Reactor (SC-GFR) concept.

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven Alan; Parma, Edward J., Jr.; Suo-Anttila, Ahti Jorma (Computational Engineering Analysis, Albuquerque, NM); Al Rashdan, Ahmad (Texas A& M University, College Station, TX); Tsvetkov, Pavel Valeryevich (Texas A& M University, College Station, TX); Vernon, Milton E.; Fleming, Darryn D.; Rochau, Gary Eugene

    2011-05-01

    This report describes the supercritical carbon dioxide (S-CO{sub 2}) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO{sub 2} as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO{sub 2} Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

  10. Shale-Gas Experience as an Analog for Potential Wellbore Integrity Issues in CO2 Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Carey, James W. [Los Alamos National Laboratory; Simpson, Wendy S. [Los Alamos National Laboratory; Ziock, Hans-Joachim [Los Alamos National Laboratory

    2011-01-01

    Shale-gas development in Pennsylvania since 2003 has resulted in about 19 documented cases of methane migration from the deep subsurface (7,0000) to drinking water aquifers, soils, domestic water wells, and buildings, including one explosion. In all documented cases, the methane leakage was due to inadequate wellbore integrity, possibly aggravated by hydrofracking. The leakage of methane is instructive on the potential for CO{sub 2} leakage from sequestration operations. Although there are important differences between the two systems, both involve migrating, buoyant gas with wells being a primary leakage pathway. The shale-gas experience demonstrates that gas migration from faulty wells can be rapid and can have significant impacts on water quality and human health and safety. Approximately 1.4% of the 2,200 wells drilled into Pennsylvania's Marcellus Formation for shale gas have been implicated in methane leakage. These have resulted in damage to over 30 domestic water supplies and have required significant remediation via well repair and homeowner compensation. The majority of the wellbore integrity problems are a result of over-pressurization of the wells, meaning that high-pressure gas has migrated into an improperly protected wellbore annulus. The pressurized gas leaks from the wellbore into the shallow subsurface, contaminating drinking water or entering structures. The effects are localized to a few thousands of feet to perhaps two-three miles. The degree of mixing between the drinking water and methane is sufficient that significant chemical impacts are created in terms of elevated Fe and Mn and the formation of black precipitates (metal sulfides) as well as effervescing in tap water. Thus it appears likely that leaking CO{sub 2} could also result in deteriorated water quality by a similar mixing process. The problems in Pennsylvania highlight the critical importance of obtaining background data on water quality as well as on problems associated with

  11. CO2 Allowance Allocation in the Regional Greenhouse Gas Initiative and the Effect on Electricity Investors

    OpenAIRE

    Burtraw, Dallas; Palmer, Karen; Kahn, Daniel

    2005-01-01

    The Regional Greenhouse Gas Initiative (RGGI) is an effort by nine Northeast and Mid-Atlantic states to develop a regional, mandatory, market-based cap-and-trade program to reduce greenhouse gas (GHG) emissions from the electricity sector. The initiative is expected to lead to an increase in the price of electricity in the RGGI region and beyond. The implications of these changes for the value of electricity-generating assets and the market value of the firms that own them depends on the init...

  12. Comparative study between gas phase and liquid phase for the production of DMC from methanol and CO2

    Institute of Scientific and Technical Information of China (English)

    Ahmed Aouissi; Salem S. Al-Deyab

    2012-01-01

    Direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide over Co1.5PW12O40 in liquid and in gas phase is investigated.The synthesized catalyst has been characterized by means of FTIR and XRD.Liquid phase experiment results showed that high pressures are favorable for the synthesis of DMC.However,DMC formation is limited by the reaction with co-produced water.DMC selectivity is more strongly dependent on the temperature than on the pressure of CO2.As for the reactions in gas phase,it has been found that both CH3OH conversion and DMC selectivity decreased with increasing temperature,owing to the decomposition of DMC at high temperatures.High temperatures and more amount of Co1.5PW12O40 catalyst favor the formation of dimethoxymethane (DMM) and methyl formate (MF).

  13. Enthalpy of the gas-phase CO2 + Mg reaction from ab initio total energies.

    Science.gov (United States)

    Lesar, Antonija; Prebil, Sasa; Hodoscek, Milan

    2002-01-01

    Various highly accurate ab initio composite methods of Gaussian-n (G1, G2, G3), their variations (G2(MP2), G3(MP2), G3//B3LYP, G3(MP2)//B3LYP), and complete basis set (CBS-Q, CBS-Q//B3LYP) series of models were applied to compute reaction enthalpies of the ground-state reaction of CO2 with Mg. All model chemistries predict highly endothermic reactions, with DeltaH(298) = 63.6-69.7 kcal x mol(-1). The difference between the calculated reaction enthalpies and the experimental value, evaluated with recommended experimental standard enthalpies of formation for products and reactants, is more than 20 kcal x mol(-1) for all methods. This difference originates in the incorrect experimental enthalpy of formation of gaseous MgO given in thermochemical databases. When the theoretical formation enthalpy for MgO calculated by a particular method is used, the deviation is reduced to 1.3 kcal x mol(-1). The performance of the methodologies used to calculate the heat of this particular reaction and the enthalpy of formation of MgO are discussed.

  14. Effect of HCO3- concentration on CO2 corrosion in oil and gas fields

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effect of HCO3- concentration on CO2 corrosion was investigated by polarization measurement of potentiodynamic scans and weight-loss method. Under the conditions of high pressure and high temperature, the corrosion rate of steel X65 decreased with the increase of HCO3- concentration, while pH of solution increased. SEM, EDS, and XRD results of the corrosion scales indicated that the typical FeCO3 crystallite was found at low HCO3- concentration but Ca(Fe,Mg)(CO3)2 was found at high HCO3 concentration. Ca2+ and Mg2+ are precipitated preferential to Fe2+ at high pH value. Potentiodynamic polarization curves showed that the cathodic current density decreases with the increase of HCO3- concentration at low HCO3- concentration. When the HCO3- concentration reaches 0.126 mol/L, increasing HCO3 concentration promotes cathodic reactions. Anodic behavior is an active process at low HCO3- concentration and the anodic current density decreases with the increase of HCO3- concentration. An evident active-passive behavior is exhibited in anodic process at 0.126 mol/L HCO3-.

  15. A Study of CO2 Injection Parameter for Gas Channeling Prevention in Fractured Reservoir with Ultra -Low Permeability%超低渗裂缝性油藏 CO2驱防气窜注入参数研究

    Institute of Scientific and Technical Information of China (English)

    周勤; 张永刚

    2015-01-01

    Gas channeling prevention is the key factor for improving CO 2 -injection-aided development effect of frac‐tured reservoir with ultra -low permeability .The root cause of gas channeling is that the crack will open when bot‐tom hole pressure of injection well surpasses its re -open pressure .Through analyzing shaft heat transfer process , establishing coupling model of CO 2 injected shaft temperature pressure and optimizing injection parameter ,its bottom hole pressure is guaranteed to be under crack re -open pressure .In addition ,indoor measures are taken such as u‐sing Waring -Blender method ,selecting suitable foaming system ,improving gas liquid ratio and other parameters and plugging re-open cracks .All this controls gas channeling and ensures increase of CO 2 -injection-aided oil re‐covery in Honghe Oilfield .%防止气窜是提高超低渗裂缝性油藏注 CO2开发效果的关键因素,气窜发生的根本原因是注入井井底压力超过裂缝重张压力导致裂缝开启。通过分析井筒传热过程,利用传热学理论等理论,建立注CO2井筒温度压力耦合模型,对注入参数进行合理优化,保证注入井井底压力低于裂缝重张压力;同时室内采用 Waring-Blender法,优选合适的起泡剂体系,优化气液比等参数,对重张裂缝进行封堵,有效控制了气窜,保证了红河油田注 CO2提高采收率的开发效果,对应油井在注 CO2后含水率下降明显,日均产油由注 CO2前的1.5 t/d增加到2.4 t/d。

  16. Pure- and mixed-gas CO2/CH4 separation properties of PIM-1 and an amidoxime-functionalized PIM-1

    KAUST Repository

    Swaidan, Raja

    2014-05-01

    The prototypical solution-processable polymer of intrinsic microporosity, PIM-1, and derivatives thereof offer combinations of permeability and selectivity that make them potential candidate materials for membrane-based gas separations. Paramount to the design and evaluation of PIMs for economical natural gas sweetening is a high and stable CO2/CH4 selectivity under realistic, mixed-gas conditions. Here, amidoxime-functionalized PIM-1 (AO-PIM-1) was prepared and examined for fundamental structure/property relationships. Qualitative NLDFT pore-size distribution analyses of physisorption isotherms (N2 at -196 oC; CO2 at 0 oC) reveal a tightened microstructure indicating size-sieving ultra-microporosity (<7Å). AO-PIM-1 demonstrated a three-fold increase in αD(CO2/CH4) over PIM-1, surpassing the 2008 upper bound with P(CO2)=1153Barrer and ideal α(CO2/CH4)=34. Under a 50:50 CO2:CH4 mixed-gas feed, AO-PIM-1 showed less selectivity loss than PIM-1, maintaining a mixed-gas α(CO2/CH4) ~21 across a 20bar pressure range. Conversely, PIM-1 endured up to 60% increases in mixed-gas CH4 permeability over pure-gas values concurrent with a selectivity of only ~8 at 20bar. A pervasive intermolecular hydrogen bonding network in AO-PIM-1 predominantly yields a rigidified microstructure that mitigates CO2-induced matrix dilations, reducing detrimental mixed-gas CH4 copermeation. © 2014 Elsevier B.V.

  17. Mechanisms for CO2 Sequestration in Geological Formations and Enhanced Gas Recovery

    NARCIS (Netherlands)

    Khosrokhavar, R.

    2014-01-01

    The work described in this thesis deals with a variety of aspects related to the storage of carbon dioxide in geological formations. In particular we focus on the transfer between the gas phase to a fluid (liquid) or solid phase. This thesis limits its interest to study the sequestration capacity of

  18. Mechanisms for CO2 Sequestration in Geological Formations and Enhanced Gas Recovery

    NARCIS (Netherlands)

    Khosrokhavar, R.

    2014-01-01

    The work described in this thesis deals with a variety of aspects related to the storage of carbon dioxide in geological formations. In particular we focus on the transfer between the gas phase to a fluid (liquid) or solid phase. This thesis limits its interest to study the sequestration capacity of

  19. Effect of matrix wettability CO2 assisted gas-oil garvity drainage in naturally fractured reservoirs

    NARCIS (Netherlands)

    Amerighasrodashti, A.; Farajzadeh, R.; Shojai Kaveh, N.; Suicmez, S.; Wolf, K.H.A.A.; Bruining, J.

    2015-01-01

    The wettability behavior of the matrix block is one of the major factors controlling the effectiveness of the employed EOR methods in NFRs. Water injection in NFRs with mixed-wet or effectively oil-wet matrix blocks usually results in low oil recoveries. In this case, gas injection is considered to

  20. Greenhouse Gas (CO2 AND N2O Emissions from Soils: A Review Emisión de Gases invernadero (CO2 y N2O desde Suelos

    Directory of Open Access Journals (Sweden)

    Cristina Muñoz

    2010-09-01

    Full Text Available In agricultural activities, the main greenhouse gases (GHG are those related to C and N global cycles. The impact of agriculture on GHG emissions has become a key issue, especially when considering that natural C and N cycles are influenced by agricultural development. This review focuses on CO2 and N2O soil emissions in terrestrial ecosystems, with emphasis in Chilean and similar agro-ecosystems around the world. The influence of land use and crop management practices on CO2 and N2O emissions is analyzed; some mitigation measures to reduce such emissions are also discussed here. More knowledge on the biological processes that promote of GHG emissions from soil will allow creating opportunities for agricultural development under friendly-environmental conditions, where soil can act as a reservoir and/or emitter of GHG, depending on the balance of inputs and outputs.En actividades agrícolas los principales gases de efecto invernadero (GHG son los relacionados con los ciclos globales de C y N. El impacto de la agricultura sobre las emisiones GHG se ha convertido en una cuestión clave, especialmente si se considera que los ciclos naturales C y N se ven influidos por el desarrollo agrícola. Esta revisión se centra en emisiones de CO2 y N2O del suelo en los ecosistemas terrestres, con énfasis en agro-ecosistemas de Chile y similares alrededor del mundo. Se analiza la influencia del uso del suelo y las prácticas de manejo del cultivo sobre emisiones de CO2 y N2O, se discuten medidas de mitigación para reducir estas emisiones. Un mayor conocimiento sobre los procesos biológicos que promueven las emisiones GHG del suelo permitirá la creación de oportunidades para el desarrollo agrícola en condiciones ambientalmente amigables, donde el suelo puede actuar como un reservorio y/o emisor de GHG, dependiendo del balance de entradas y salidas.

  1. Spatial and Temporal Variability of Carbon Dioxide Using Structure Functions in Urban Areas: Insights for Future Active Remote CO2 Sensors

    Science.gov (United States)

    Choi, Yonghoon; Yang, Melissa; Kooi, Susan A.; Browell, Edward V.; DiGangi, Joshua P.

    2015-01-01

    High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaigns during July 2011 over Washington DC/Baltimore, MD; January-February 2013 over the San Joaquin Valley, CA; September 2013 over Houston, TX; and July-August 2014 over Denver, CO. Each of these campaigns have approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 kilometers) at 6-8 different sites in each of the urban areas. In this study, we used structure function analysis, which is a useful way to quantify spatial and temporal variability, by displaying differences with average observations, to evaluate the variability of CO2 in the 0-2 kilometers range (representative of the planetary boundary layer). These results can then be used to provide guidance in the development of science requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission to measure near-surface CO2 variability in different urban areas. We also compare the observed in-situ CO2 variability with the variability of the CO2 column-averaged optical depths in the 0-1 kilometer and 0-3.5 kilometers altitude ranges in the four geographically different urban areas, using vertical weighting functions for potential future ASCENDS lidar CO2 sensors operating in the 1.57 and 2.05 millimeter measurement regions. In addition to determining the natural variability of CO2 near the surface and in the column, radiocarbon method using continuous CO2 and CO measurements are used to examine the variation of emission quantification between anthropogenic and biogenic sources in the DC/Maryland urban site.

  2. A frequency-stabilized laser based on a hollow-core photonic crystal fiber CO2 gas cell and its application scheme

    Science.gov (United States)

    Chen, Ze-Heng; Yang, Fei; Chen, Di-Jun; Cai, Hai-Wen

    2017-04-01

    A frequency-stabilized laser system based on a hollow-core photonic crystal fiber (HC-PCF) CO2 gas cell for the space-borne CO2 light detection and ranging (LIDAR) is proposed. This system will help realize precise measurement of the global atmospheric CO2 concentrations. The relation between the frequency stability and the temperature of the HC-PCF cell was studied in detail. It is proved that accurate control of the temperature of the HC-PCF cell is very important to realize high stability of the proposed system. The laser is locked to CO2 gas R18 absorption line at 1572.0179 nm, and its peak-to-peak frequency stability is approximately 485 kHz, satisfying the requirements for the integrated path differential absorption system for CO2 measurement with an accuracy of  <1 ppm over 5 h.

  3. Effect of flue gas CO2 on the growth, carbohydrate and fatty acid composition of a green microalga Scenedesmus obliquus for biofuel production.

    Science.gov (United States)

    Ji, Min-Kyu; Yun, Hyun-Shik; Hwang, Jae-Hoon; Salama, El-Sayed; Jeon, Byong-Hun; Choi, Jaeyoung

    2016-10-31

    Effect of various flue gas CO2 concentrations (5%, 10% and 14.1%) on growth rate and biochemical properties of a green microalga Scenedesmus obliquus was investigated. S. obliquus showed the highest biomass production and growth rate (0.36 g L(-1) and μmax = 1.00 day(-1)), total inorganic carbon removal (35.8 mg L(-1)), lipid productivity (9.9 mg L(-1) day) and carbohydrate productivity (10.3 mg L(-1) day) with 14.1% CO2 after 8 days of cultivation. Fatty acid methyl ester analysis revealed that the palmitic and oleic acid contents were increased up to 5% and 7% with 14.1% CO2, respectively. Application of flue gas CO2 enhanced the growth along with lipid and carbohydrate productivity of S. obliquus, which can be exploited for reducing the CO2 concentration.

  4. Porous Silicon Structures as Optical Gas Sensors

    Directory of Open Access Journals (Sweden)

    Igor A. Levitsky

    2015-08-01

    Full Text Available We present a short review of recent progress in the field of optical gas sensors based on porous silicon (PSi and PSi composites, which are separate from PSi optochemical and biological sensors for a liquid medium. Different periodical and nonperiodical PSi photonic structures (bares, modified by functional groups or infiltrated with sensory polymers are described for gas sensing with an emphasis on the device specificity, sensitivity and stability to the environment. Special attention is paid to multiparametric sensing and sensor array platforms as effective trends for the improvement of analyte classification and quantification. Mechanisms of gas physical and chemical sorption inside PSi mesopores and pores of PSi functional composites are discussed.

  5. Recognizing frequency characteristics of gas sensor array

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel method based on independent component analyzing (ICA) in frequency domain to distinguish the frequency characteristics of multi-sensor system is presented. The conditions of this type of ICA are considered and each step of resolving the problem is discussed. For a two gas sensor array, the frequency characteristics including amplitude-frequency and phase-frequency are recognized by this method, and cross-sensitivity between them is also eliminated. From the principle of similarity, the recognition m...

  6. Surrogate gas prediction model as a proxy for Δ14C-based measurements of fossil fuel CO2

    Science.gov (United States)

    Coakley, Kevin J.; Miller, John B.; Montzka, Stephen A.; Sweeney, Colm; Miller, Ben R.

    2016-06-01

    The measured 14C:12C isotopic ratio of atmospheric CO2 (and its associated derived Δ14C value) is an ideal tracer for determination of the fossil fuel derived CO2 enhancement contributing to any atmospheric CO2 measurement (Cff). Given enough such measurements, independent top-down estimation of U.S. fossil fuel CO2 emissions should be possible. However, the number of Δ14C measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Δ14C is therefore measured in just a small fraction of samples obtained by flask air sampling networks around the world. Here we develop a projection pursuit regression (PPR) model to predict Cff as a function of multiple surrogate gases acquired within the NOAA/Earth System Research Laboratory (ESRL) Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF6, and halocarbon and hydrocarbon acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 to 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi-square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Δ14C measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of

  7. Surrogate gas prediction model as a proxy for Δ(14)C-based measurements of fossil fuel-CO2.

    Science.gov (United States)

    Coakley, Kevin J; Miller, John B; Montzka, Stephen A; Sweeney, Colm; Miller, Ben R

    2016-06-27

    The measured (14)C:(12)C isotopic ratio of atmospheric CO2 (and its associated derived Δ(14)C value) is an ideal tracer for determination of the fossil fuel derived CO2 enhancement contributing to any atmospheric CO2 measurement (Cff ). Given enough such measurements, independent top-down estimation of US fossil fuel-CO2 emissions should be possible. However, the number of Δ(14)C measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Δ(14)C is therefore measured in just a small fraction of samples obtained by ask air sampling networks around the world. Here, we develop a Projection Pursuit Regression (PPR) model to predict Cff as a function of multiple surrogate gases acquired within the NOAA/ESRL Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF6, and halo- and hydrocarbons acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 through 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi-square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Δ(14)C measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of uncertainties and

  8. Understanding the interaction of injected CO2 and reservoir fluids in the Cranfield enhanced oil recovery (EOR) field (MS, USA) by non-radiogenic noble gas isotopes

    Science.gov (United States)

    Gyore, Domokos; Stuart, Finlay; Gilfillan, Stuart

    2016-04-01

    Identifying the mechanism by which the injected CO2 is stored in underground reservoirs is a key challenge for carbon sequestration. Developing tracing tools that are universally deployable will increase confidence that CO2 remains safely stored. CO2 has been injected into the Cranfield enhanced oil recovery (EOR) field (MS, USA) since 2008 and significant amount of CO2 has remained (stored) in the reservoir. Noble gases (He, Ne, Ar, Kr, Xe) are present as minor natural components in the injected CO2. He, Ne and Ar previously have been shown to be powerful tracers of the CO2 injected in the field (Györe et al., 2015). It also has been implied that interaction with the formation water might have been responsible for the observed CO2 loss. Here we will present work, which examines the role of reservoir fluids as a CO2 sink by examining non-radiogenic noble gas isotopes (20Ne, 36Ar, 84Kr, 132Xe). Gas samples from injection and production wells were taken 18 and 45 months after the start of injection. We will show that the fractionation of noble gases relative to Ar is consistent with the different degrees of CO2 - fluid interaction in the individual samples. The early injection samples indicate that the CO2 injected is in contact with the formation water. The spatial distribution of the data reveal significant heterogeneity in the reservoir with some wells exhibiting a relatively free flow path, where little formation water is contacted. Significantly, in the samples, where CO2 loss has been previously identified show active and ongoing contact. Data from the later stage of the injection shows that the CO2 - oil interaction has became more important than the CO2 - formation water interaction in controlling the noble gas fingerprint. This potentially provides a means to estimate the oil displacement efficiency. This dataset is a demonstration that noble gases can resolve CO2 storage mechanisms and its interaction with the reservoir fluids with high resolution

  9. The Residual Gas Saturation of Different Components of Saline Flooding CO2%不同成分盐水驱CO2的残余气饱和度

    Institute of Scientific and Technical Information of China (English)

    武爱兵; 李铱; 常春; 于青春

    2014-01-01

    In many mechanisms of the geological storage of CO2 in deep saline aquifers,the trapped gas storage has great potential,which accounts for about 30% of the total storage.Residual gas saturation is a very impor-tant parameter to evaluate storage capacity of trapped gas.This thesis can qualitatively evaluate storage capacity of trapped gas in different saline aquifers and provide basic parameters for assessing of storage capacity in deep saline aquifers by measuring residual CO2 saturation of different components of saline flooding CO2 .At the same time,it can give some guidances and references in choosing the project site and the target aquifer of the geologi-cal storage of CO2 in deep saline aquifers.We used distilled water,NaCl solution,CaCl2 solution and the mix-ture of NaCl and CaCl2 solution (the mass ratio is 1∶1),which were all saturated by CO2 and the mass concen-tration of all solutions is 10%,to inject into CO2-saturated core and finally we calculated residual CO2 satura-tion.The injection process can be divided into two phases:piston drainage,portable drainage.Experimental results show that the ascending order of residual CO2 saturation of four kinds of liquid flooding is distilled water, the mixture solution,NaCl solution and CaCl2 solution.The results indicate that interfacial tension plays a domi-nant role in the injection process under the influence of interfacial tension and fluid viscosity.Among the three types of saline,storage potential of trapped gas of Cl-Ca-type water is maximum,followed by Cl-Na-type water. The potential of Cl-Na·Ca-type water is minimum.%CO2在地下深部咸水含水层地质封存的多种封存机理中,束缚气封存的潜力很大,可占封存总量的30%左右。残余气饱和度是评价束缚气封存量的一个十分重要的参数。通过测定不同成分盐水驱 CO2的残余 CO2饱和度,对不同咸水含水层的束缚气封存潜力进行定性的评价,进一步为深部咸水含水层的 CO2

  10. Research of CO2 enrichment by utilization of post purification waste gas%净化后废气作为CO2气肥的施用效果研究

    Institute of Scientific and Technical Information of China (English)

    康康; 呼世斌

    2012-01-01

    【目的】研究净化后废气作为CO2气肥对温室黄瓜植株、果实的生长性状及产量、果实品质的影响,旨在为工业废气的农业资源化利用提供实验依据。【方法】自2011-03-28开始,用自制气肥发生器净化小型民用锅炉产生废气,将废气转化为不同浓度(400(CK),900,1 200,1 500μmol/mol)CO2气肥并通施于温室黄瓜,气肥通施持续2个月,测定不同浓度CO2气肥处理黄瓜的株高、茎粗、瓜条长度、瓜粗、产量及果实品质。【结果】随着通气时间的延长,各CO2气肥处理和CK黄瓜的株高、茎粗、瓜条长度、瓜粗均呈显著增大趋势,其中1 500μmol/mol CO2气肥处理的各项生长指标均明显高于其他处理。与CK相比,900,1 200,1 500μmol/mol CO2气肥处理黄瓜的总产量分别提高了12.1%,15.0%,19.7%。随着CO2气肥浓度的增加,黄瓜果实中的Vc和可溶性糖含量逐渐增大,硝酸盐含量明显降低,其中1 500μmol/mol CO2气肥处理的Vc和可溶性糖含量最高,硝酸盐含量最低。【结论】通施CO2气肥可促进温室黄瓜植株和果实的生长,提高黄瓜果实的产量和品质。CO2气肥的最佳施用浓度为1 500μmol/mol。%【Objective】The research of this experiment was to study the effects of CO2 enrichment on greenhouse cucumbers in terms of plant growth characters,production and internal quality of cucumber fruits,and to provide basis for the agricultural utilization of industrial waste gas.【Method】Waste gas from mini type civil boiler was purified in a self-built CO2 fertilizer generator and converted into CO2 gas fertilizer.Since 2011-03-28,the gas fertilizer was applied on greenhouse cucumbers by different concentrations(400(CK),900,1 200,1 500 μmol/mol)for 2 months.Measurements of the cucumbers were conducted in terms of plant height,stem diameter,fruit length,fruit diameter,production and fruit qualities.【Result】As the CO2 enrichment prolonged,the plant

  11. Greenhouse Gas (CH4, CO2 and N2O) Emission Levels by Wastewater Treatment Plant (WWTP) Ponds in Brazil

    Science.gov (United States)

    Rossete, A. L. M.; Sundefeld Junior, G.; Aparicio, C.; Baldi, G. G.; Montes, C. R.; Piveli, R. P.; Melfi, A. J.

    2015-12-01

    This study measured greenhouse gas emissions (GHG) by Facultative Ponds on Wastewater Treatment Plants. The most studied GHGs include CO2, CH4and N2O. The level of GHG (CO2, CH4 and N2O) emissions by WWTPs in Australian-type stabilization ponds was measured in the city of Lins (22º21'S, 49º50'W), state of São Paulo (SP), Brazil. GHG collection was carried outusing a collection chamber installed at the center of the facultative pond's final third. The effluent's pH and temperature (ET) were registered by probes, and meteorological information regarding air temperature (AT) and solar radiation (SR) were obtained from INMET, Brazil. GHG collection was carried out for 72 consecutive hours in June 2014, on an hourly basis, once every 5 minutes, for the first 30 minutes, and once every 10 minutes from 30 to 50 minutesand subsequently analyzed by gas chromatograph (GC).After three days of data collection, the average AT, SR, ET and pH values were, respectively, 18oC, 2583kJm-2, 23oC and 8.2. Average values for GHG emission levels (CH4, CO2 and N2O) were 79.01; 100.65 and 0.0 mg m-2 h-1, respectively. GHG emission levels were divided into light periods (morning, afternoon and evening)in order to verify the periods with the highest GHG emissions.The highest CH4 emission levels were measured between morning and early afternoon. The maximum CO2 emissions were observed from evening to early morning. N2O emissions were constant and values were close to the ones found in the atmosphere, which shows the emission of N2O by facultative ponds does not contribute to greenhouse gases emissions.The results enabled us to characterize and quantify GHG emission levels per Facultative Pond on Wastewater Treatment Plant. Acknowledgment to FAPESP and SABESP, Brazil.

  12. Ultrasensitive and highly selective graphene-based single yarn for use in wearable gas sensor.

    Science.gov (United States)

    Yun, Yong Ju; Hong, Won G; Choi, Nak-Jin; Kim, Byung Hoon; Jun, Yongseok; Lee, Hyung-Kun

    2015-06-04

    Electric components based on fibers or textiles have been investigated owing to their potential applications in wearable devices. High performance on response to gas, drape-ability and washing durability are of important for gas sensors based on fiber substrates. In this report, we demonstrate the bendable and washable electronic textile (e-textile) gas sensors composed of reduced graphene oxides (RGOs) using commercially available yarn and molecular glue through an electrostatic self-assembly. The e-textile gas sensor possesses chemical durability to several detergent washing treatments and mechanical stability under 1,000 bending tests at an extreme bending radius of 1 mm as well as a high response to NO2 gas at room temperature with selectivity to other gases such as acetone, ethanol, ethylene, and CO2.

  13. Ultrasensitive and Highly Selective Graphene-Based Single Yarn for Use in Wearable Gas Sensor

    Science.gov (United States)

    Ju Yun, Yong; Hong, Won G.; Choi, Nak-Jin; Hoon Kim, Byung; Jun, Yongseok; Lee, Hyung-Kun

    2015-06-01

    Electric components based on fibers or textiles have been investigated owing to their potential applications in wearable devices. High performance on response to gas, drape-ability and washing durability are of important for gas sensors based on fiber substrates. In this report, we demonstrate the bendable and washable electronic textile (e-textile) gas sensors composed of reduced graphene oxides (RGOs) using commercially available yarn and molecular glue through an electrostatic self-assembly. The e-textile gas sensor possesses chemical durability to several detergent washing treatments and mechanical stability under 1,000 bending tests at an extreme bending radius of 1 mm as well as a high response to NO2 gas at room temperature with selectivity to other gases such as acetone, ethanol, ethylene, and CO2.

  14. Combined Vacuum and Temperature Swing Adsorption Process for CO2 Capture from Flue Gas%真空变压变温耦合吸附过程捕集烟道气中CO2的研究

    Institute of Scientific and Technical Information of China (English)

    刘振; 王璐; 李平; 于建国

    2012-01-01

    研究了用六步真空变温变压耦合吸附工艺(VTSA)捕集烟道气中CO2的过程。考察了不同再生温度和压力下用VTSA工艺分离CO2的效果。在压力为10kPa和温度为423K的再生条件下,烟道气中CO2的纯度由15.0%增至93.4%,同时具有95.4%的回收率。对六步VTSA工艺过程进行了模拟,并通过实验结果对模型进行验证。最后模拟了一个不包含降温过程的五步VTSA工艺,以提高吸附剂的产率。%A six-step combined vacuum and temperature swing adsorption process(VTSA)was studied for CO2 capture from flue gas. Experiments under different regeneration conditions were investigated and the VTSA performance for CO2 separation was evaluated. Purity of CO2 from flue gas can be concentrated from 15.0% to 93.4% with a recovery of 95.4% under desorption at 10 kPa and 423 K. Simulations were also performed and the model was verified by the experimental results. Finally, a modified five-step VTSA cycle without cooling step was also proposed to enhance the unit productivity.

  15. Storage of CO2 at low temperature as liquid or solid gas hydrate - Application to the Biscay deep zone in the French EEZ

    Science.gov (United States)

    Burnol, André; Thinon, Isabelle; Audigane, Pascal; Leynet, Aurélien

    2013-04-01

    Amongst the various CO2 geological storage options currently under consideration, the deep saline aquifers (beyond 800-m depth) were considered to present the most interesting storage capacity due to the density of CO2 in its supercritical state. However, at lower temperature, another form of storage is possible, either in the state of CO2 hydrates or liquid CO2 (1, 2). In Alaska, a first demonstrator showed recently the possibility of exchange of CO2 and CH4 in natural gas hydrates. At higher pressures common in deep-sea sediments, liquid CO2 can be denser than the overlying seawater and therefore be trapped in the marine sediments (2). We explored in this work the storage capacity at the Biscay deep zone in the French Exclusive Economic Zone (EEZ). A local bathymetry of the zone (abyssal plain and continental margin) was used to define a potential interesting zone for the CO2 storage, considering different safety criteria. A sensitivity analysis on the geothermal gradient was carried out using two extreme scenarios (Low and High gradient) based on the available Ocean Drilling Program's data. In both cases, the Negative Buoyancy Zone (NBZ) and the CO2 Hydrate Formation Zone (HFZ) were calculated using the GERG-2008 Equation of State for liquid CO2 and the CSMGem code for CO2 hydrate, respectively. Following this sensitivity analysis, a CO2 injection depth is proposed and the French "deep offshore" storage capacity is quantitatively evaluated and compared to the "onshore" storage capacity in deep saline aquifers. References 1. Le Nindre Y., Allier D., Duchkov A., Altunina L. K., Shvartsev S., Zhelezniak M. and Klerkx J. (2011) Storing CO2 underneath the Siberian Permafrost: A win-win solution for long-term trapping of CO2 and heavy oil upgrading. Energy Procedia4, 5414-5421 2. House K. Z., Schrag D. P., Harvey C. F. and Lackner K. S. (2006) Permanent carbon dioxide storage in deep-sea sediments. PNAS

  16. The Precise Mechanisms of a High-Speed Ultrasound Gas Sensor and Detecting Human-Specific Lung Gas Exchange

    Directory of Open Access Journals (Sweden)

    Hideki Toda

    2012-12-01

    Full Text Available In this paper, we propose and develop a new real-time human respiration process analysis method using a high-time-sampling gas concentration sensor based on ultrasound. A unique point about our proposed gas concentration sensor is its 1 kHz gas concentration sampling speed. This figure could not have been attained by previously proposed gas concentration measurement methods such as InfraRed, semiconductor gas sensors, or GC-MS, because the gas analysis speeds were a maximum of a few hundred milliseconds. First, we describe the proposed new ultrasound sound speed measurement method and the signal processing, and present the measurement circuit diagram. Next, we analyse the human respiration gas variation patterns of five healthy subjects using a newly developed gas-mask-type respiration sensor. This reveals that the rapid gas exchange from H2O to CO2 contains air specific to the human being. In addition, we also measured medical symptoms in subjects suffering from asthma, hyperventilation and bronchial asthma. The millisecond level high-speed analysis of the human respiration process will be useful for the next generation of healthcare, rehabilitation and sports science technology.

  17. Influence of Metal Transfer Stability and Shielding Gas Composition on CO and CO2 Emissions during Short-circuiting MIG/MAG Welding

    Directory of Open Access Journals (Sweden)

    Valter Alves de Meneses

    Full Text Available Abstract: Several studies have demonstrated the influence of parameters and shielding gas on metal transfer stability or on the generation of fumes in MIG/MAG welding, but little or nothing has been discussed regarding the emission of toxic and asphyxiating gases, particularly as it pertains to parameterization of the process. The purpose of this study was to analyze and evaluate the effect of manufacturing aspects of welding processes (short-circuit metal transfer stability and shielding gas composition on the gas emission levels during MIG/MAG welding (occupational health and environmental aspects. Using mixtures of Argon with CO2 and O2 and maintaining the same average current and the same weld bead volume, short-circuit welding was performed with carbon steel welding wire in open (welder’s breathing zone and confined environments. The welding voltage was adjusted to gradually vary the transfer stability. It was found that the richer the composition of the shielding gas is in CO2, the more CO and CO2 are generated by the arc. However, unlike fume emission, voltage and transfer stability had no effect on the generation of these gases. It was also found that despite the large quantity of CO and CO2 emitted by the arc, especially when using pure CO2 shielding gas, there was no high level residual concentration of CO and CO2 in or near the worker’s breathing zone, even in confined work cells.

  18. SnO2 Nanostructure as Pollutant Gas Sensors: Synthesis, Sensing Performances, and Mechanism

    Directory of Open Access Journals (Sweden)

    Brian Yuliarto

    2015-01-01

    Full Text Available A significant amount of pollutants is produced from factories and motor vehicles in the form of gas. Their negative impact on the environment is well known; therefore detection with effective gas sensors is important as part of pollution prevention efforts. Gas sensors use a metal oxide semiconductor, specifically SnO2 nanostructures. This semiconductor is interesting and worthy of further investigation because of its many uses, for example, as lithium battery electrode, energy storage, catalyst, and transistor, and has potential as a gas sensor. In addition, there has to be a discussion of the use of SnO2 as a pollutant gas sensor especially for waste products such as CO, CO2, SO2, and NOx. In this paper, the development of the fabrication of SnO2 nanostructures synthesis will be described as it relates to the performances as pollutant gas sensors. In addition, the functionalization of SnO2 as a gas sensor is extensively discussed with respect to the theory of gas adsorption, the surface features of SnO2, the band gap theory, and electron transfer.

  19. CO2气体保护焊在水工钢结构制造中的工艺应用%The application of the CO2 gas shielded arc welding in hydraulic steel structures

    Institute of Scientific and Technical Information of China (English)

    方仕庆; 曹振锋

    2012-01-01

    CO2气体保护焊技术已大量的应用于水工钢结构施工工艺中,其具有焊接速度快、效率高、成型好和变形小的突出特点。本篇主要介绍的是CO2气体保护焊在水工钢结构施工中焊材的选用、焊接工艺、实际操作等应用方面的问题。%CO2 gas shielded arc welding technology have been widely used in hydraulic steel structure construction,which has special advantages of the welding speed fast,high efficiency,easy forming and small deformation.This paper describes the selection,welding process,and practical application aspects of CO2 gas shielded welding in the construction of hydraulic steel structures.

  20. CO2气体保护焊在钢结构制作中的工艺应用%Application of CO2 gas shield protection technology in steel structure fabrication

    Institute of Scientific and Technical Information of China (English)

    邓瑞芬

    2014-01-01

    The paper analyzes CO2 gas shield protection welding technology from four aspects of welding stick selection,welding current method, arc voltage selection,welding stick prolong selection,and describes CO2 gas shield protection technology in steel structure fabrication,such as welding gun,arc starting and arc stopping and welding joints processing methods,which has provided some technology support for its application.%从焊丝选择方式、焊接电流方式、电弧电压选择、焊丝干伸长选择四方面对 CO2气体保护焊接工艺进行了分析,并对 CO2气体保护焊接在钢结构制作工艺中焊枪、引弧与收弧以及焊缝处理方法作了阐述,为其推广应用提供了技术支持。

  1. Test and Analysis on Phase Features of High-CO2 Condensate Gas%高含CO2凝析气相态测试及分析

    Institute of Scientific and Technical Information of China (English)

    余华杰; 王星; 谭先红; 田波

    2013-01-01

    To determine a suitable development mode and enhance condensate oil recovery in high-CO2 condensate gas reservoir, the phase changing behavior of condensate gas flow in the development process was identified. The HTHP Multi-functional Fluid Analyzer was used in single flash vaporization test,dew point pressure test, constant component expansion test, and constant volume depletion test for high-CO2 condensate gas samples with different mole fractions,and the impacts of such fractions on the phase behavior and HP physical parameters were also compared. With higher mole fraction of CO2, the rate of retrograde condensation dropped,the peak of retrograde condensation liquid decreased by about 15%,the recovery factor of condensate oil increased by about 20%,the recovery of natural gas was about 85%,and the phase envelope curve shrank inwards. CO2 in the system contributes to higher condensate recovery by inhibiting its retrograde condensation and enhancing the retrograde vaporization. It is significant for determining a reasonable production strategy.%为了制定高含CO2凝析气藏的合理开发方式、提高凝析油采收率,需要了解高含CO2的凝析气流体在开发过程中存在的复杂相变行为.采用高温高压多功能地层流体分析仪,对不同摩尔分数CO2凝析气体系样品进行了单次闪蒸实验、露点压力测试、等组分膨胀实验和定容衰竭实验,对比分析了CO2摩尔分数对凝析气体系高压物性参数和相态特征的影响.研究结果表明,随着CO2摩尔分数的增加,凝析油的反凝析速度减缓,且最大反凝析液量减小约15%、凝析油的采出程度增加约20%、天然气采出程度为85%左右、相包络线向内收缩.富含CO2凝析气体系中的CO2既有利于抑制凝析油的反凝析,又有利于增强凝析油的反蒸发,对于提高凝析油采收率具有显著效果.

  2. Pure- and Mixed-Gas Permeation Properties of Highly Selective and Plasticization Resistant Hydroxyl-Diamine-Based 6FDA Polyimides for CO2/CH4 Separation

    KAUST Repository

    Alaslai, Nasser Y.

    2016-01-05

    The effect of hydroxyl functionalization on the m-phenylene diamine moiety of 6FDA dianhydride-based polyimides was investigated for gas separation applications. Pure-gas permeability coefficients of He, H2, N2, O2, CH4, and CO2 were measured at 35 °C and 2 atm. The introduction of hydroxyl groups in the diamine moiety of 6FDA-diaminophenol (DAP) and 6FDA-diamino resorcinol (DAR) polyimides tightened the overall polymer structure due to increased charge transfer complex formation compared to unfunctionalized 6FDA-m-phenylene diamine (mPDA). The BET surface areas based on nitrogen adsorption of 6FDA-DAP (54 m2g−1) and of 6FDA-DAR (45 m2g−1) were ~18% and 32% lower than that of 6FDA-mPDA (66 m2g−1). 6FDA-mPDA had a pure-gas CO2 permeability of 14 Barrer and CO2/CH4 selectivity of 70. The hydroxyl-functionalized polyimides 6FDA-DAP and 6FDA-DAR exhibited very high pure-gas CO2/CH4 selectivities of 92 and 94 with moderate CO2 permeability of 11 and 8 Barrer, respectively. It was demonstrated that hydroxyl-containing polyimide membranes maintained very high CO2/CH4 selectivity (~ 75 at CO2 partial pressure of 10 atm) due to CO2 plasticization resistance when tested under high-pressure mixed-gas conditions. Functionalization with hydroxyl groups may thus be a promising strategy towards attaining highly selective polyimides for economical membrane-based natural gas sweetening.

  3. Calculation of CO2 Supplying Amount and Reforming Gas Composition in One-Step Steam Reforming of Natural Gas and CO2 to Syngas for Methanol Production%天然气添加CO2一段蒸汽转化制甲醇合成气中CO2配入量及转化气组成的计算

    Institute of Scientific and Technical Information of China (English)

    雍永祜; 李国琨; 杨茗

    2005-01-01

    从合成甲醇的化学计量和蒸汽转化的物衡计算出发,推导出计算天然气前加CO2一段蒸汽转化制甲醇合成气工艺中,CO2添加量与R值之间的通用函数关系式:R=(H2-CO2)/(CO+CO2)=([(3y0CH4×nCH4)+5y0C2H6+7y0C3H8+9y0C4H10]-(δCO2+y0CO2))/([(y0CH4×nCH4)+2y0C2H6+3y0C3H8+4y0C4H10+y0CO]+(δCO2+y0CO2)).式中甲烷转化率nCH4要根据蒸汽转化的工艺条件,即m值、H2O/C比、压力、温度,选取5~10℃的平衡温距,查平衡数据表以确定.对于转化后气体中CO和CO2的分配系数则仍要根据上述工艺条件,选取30~60℃的平衡温距,查平衡数据予以确定.本文用详细的实例,将此简易计算方法介绍与读者.

  4. Carbon Disulfide (CS2) Mechanisms in Formation of Atmospheric Carbon Dioxide (CO2) Formation from Unconventional Shale Gas Extraction and Processing Operations and Global Climate Change.

    Science.gov (United States)

    Rich, Alisa L; Patel, Jay T

    2015-01-01

    Carbon disulfide (CS2) has been historically associated with the production of rayon, cellophane, and carbon tetrachloride. This study identifies multiple mechanisms by which CS2 contributes to the formation of CO2 in the atmosphere. CS2 and other associated sulfide compounds were found by this study to be present in emissions from unconventional shale gas extraction and processing (E&P) operations. The breakdown products of CS2; carbonyl sulfide (COS), carbon monoxide (CO), and sulfur dioxide (SO2) are indirect greenhouse gases (GHGs) that contribute to CO2 levels in the atmosphere. The heat-trapping nature of CO2 has been found to increase the surface temperature, resulting in regional and global climate change. The purpose of this study is to identify five mechanisms by which CS2 and the breakdown products of CS2 contribute to atmospheric concentrations of CO2. The five mechanisms of CO2 formation are as follows: Chemical Interaction of CS2 and hydrogen sulfide (H2S) present in natural gas at high temperatures, resulting in CO2 formation;Combustion of CS2 in the presence of oxygen producing SO2 and CO2;Photolysis of CS2 leading to the formation of COS, CO, and SO2, which are indirect contributors to CO2 formation;One-step hydrolysis of CS2, producing reactive intermediates and ultimately forming H2S and CO2;Two-step hydrolysis of CS2 forming the reactive COS intermediate that reacts with an additional water molecule, ultimately forming H2S and CO2. CS2 and COS additionally are implicated in the formation of SO2 in the stratosphere and/or troposphere. SO2 is an indirect contributor to CO2 formation and is implicated in global climate change.

  5. Miniaturization of a biomedical gas sensor.

    Science.gov (United States)

    Mirtaheri, Peyman; Omtveit, Tore; Klotzbuecher, Thomas; Grimnes, Sverre; Martinsen, Orjan G; Tønnessen, Tor Inge

    2004-12-01

    In a previous study, we concluded that a conductivity based PCO2 sensor is an attractive solution for early detection of ischemia and presented two design geometries. For organ surface measurements, the planar design was suitable but it was difficult to insert the sensor into the tissue. A cylindrical design solution was favored for insertion due to the large membrane contact area and easy placement in a medical catheter. Since the previous cylindrical prototype was large and could damage the tissue, a more miniaturized sensor was needed. In the current paper, we present a miniaturized sensor with an outer diameter of 1 mm. The applied technology for manufacturing the sensor was a combination of mechanical turning, excimer laser drilling and conventional molding technique. The materials applied were PEEK (polyetherether ketone), PI (polyimide) with gold layers and polysiloxane. The membrane had to be gas permeable while acting as a barrier for ion transport, and was made of polysiloxane and had a thickness of 100-150 microm. The miniaturized sensor was tested for calibration, response time, drifting and pressure sensitivity. The results show that the miniaturized PCO2 sensor is capable of rapid and stable measurements both in vitro and ex vivo. The result from this study will be applied for the industrial manufacturing of such a biomedical sensor as a clinical product.

  6. Evaluation of radiation heat transfer in porous medial: Application for a pebble bed modular reactor cooled by CO2 gas

    Directory of Open Access Journals (Sweden)

    Sidi-Ali Kamel

    2013-01-01

    Full Text Available This work analyses the contribution of radiation heat transfer in the cooling of a pebble bed modular reactor. The mathematical model, developed for a porous medium, is based on a set of equations applied to an annular geometry. Previous major works dealing with the subject have considered the forced convection mode and often did not take into account the radiation heat transfer. In this work, only free convection and radiation heat transfer are considered. This can occur during the removal of residual heat after shutdown or during an emergency situation. In order to derive the governing equations of radiation heat transfer, a steady-state in an isotropic and emissive porous medium (CO2 is considered. The obtained system of equations is written in a dimensionless form and then solved. In order to evaluate the effect of radiation heat transfer on the total heat removed, an analytical method for solving the system of equations is used. The results allow quantifying both radiation and free convection heat transfer. For the studied situation, they show that, in a pebble bed modular reactor, more than 70% of heat is removed by radiation heat transfer when CO2 is used as the coolant gas.

  7. The IRAM M33 CO(2-1) Survey - A complete census of the molecular gas out to 7 kpc

    CERN Document Server

    Druard, C; Schuster, K F; Schneider, N; Gratier, P; Bontemps, S; Boquien, M; Combes, F; Corbelli, E; Henkel, C; Herpin, F; Kramer, C; van der Tak, F; van der Werf, P

    2014-01-01

    In order to study the ISM and the interplay between the atomic and molecular components in a low-metallicity environment, we present a complete high angular and spectral resolution map and data cube of the 12CO(2-1) emission from the Local Group galaxy M33. Its metallicity is roughly half-solar, such that we can compare its ISM with that of the Milky Way with the main changes being the metallicity and the gas mass fraction. The data have a 12" angular resolution (50pc) with a spectral resolution of 2.6 km/s and a mean noise level of 20 mK per channel in antenna temperature. A radial cut along the major axis was also observed in the 12CO(1-0) line. The CO data cube and integrated intensity map are optimal when using HI data to define the baseline window and the velocities over which the CO emission is integrated. Great care was taken when building these maps, testing different windowing and baseline options and investigating the effect of error beam pickup. The total CO(2-1) luminosity is 2.8e7 K km/s pc2, fol...

  8. Gas emission from diffuse degassing structures (DDS) of the Cameroon volcanic line (CVL): Implications for the prevention of CO2-related hazards

    Science.gov (United States)

    Issa; Ohba, T.; Chako Tchamabé, B.; Padrón, E.; Hernández, P.; Eneke Takem, E. G.; Barrancos, J.; Sighomnoun, D.; Ooki, S.; Nkamdjou, Sigha; Kusakabe, M.; Yoshida, Y.; Dionis, S.

    2014-08-01

    In the mid-1980s, lakes Nyos and Monoun violently released massive gas, mainly magmatic CO2 killing about 1800 people. Subsequent geochemical surveys and social studies indicate that lakes Nyos and Monoun event is cyclic in nature and may occur anywhere in the about 37 other volcanic lakes located in the corridor of the Cameroon volcanic line (CVL). This potential threat motivated us to check if, alike Nyos and Monoun, the internal dynamic of the other lakes is also controlled by inputs of deep-seated-derived CO2 and attempt to measure and provide comprehensive insights on the passive gas emission along the CVL. This knowledge shall contribute to the prevention of volcanic lake-related hazards in Cameroon and the refinement of the Global Carbon Cycle. We used in situ fixation and dry gas phase sampling methods to determine CO2 origin and the concentration, and the accumulation chamber technique to measure diffuse CO2 emission from nine lakes and on soil at Nyos Valley and Mount Manenguba Caldera. The results suggest that, although in minor concentrations (compared to Nyos and Monoun), ranging from 0.56 mmol kg- 1 to 8.75 mmol kg- 1, the bottom waters of some lakes also contain measurable magmatic CO2 with δ13C varies from - 4.42‰ to - 9.16‰ vs. PDB. That finding implies that, under certain circumstances, e.g. increase to volcanic and/or tectonic activities along the CVL, the concerned lakes could develop a Nyos-type behavioural scheme. The diffuse gas emission results indicate that the nine surveyed lakes release approximately 3.69 ± 0.37 kt km- 2 yr- 1 of CO2 to the atmosphere; extrapolation to the approximately 39 volcanic lakes located on the CVL yields an approximate CO2 output of 27.37 ± 0.5 kt km- 2 yr- 1, representing 0.023% of the global CO2 output from volcanic lakes. In addition to the precedent value, the gas removal operation in lakes Nyos and Monoun released approximately 2.52 ± 0.46 × 108 mol km- 2 yr- 1 CO2 to the atmosphere from January

  9. Testing of hydrotalcite based sorbents for CO2 and H2S capture for use in sorption enhanced water gas shift

    Energy Technology Data Exchange (ETDEWEB)

    Van Dijk, H.A.J.; Walspurger, S.; Cobden, P.D.; Van den Brink, R.W. [ECN Hydrogen and Clean Fossil Fuels, Petten (Netherlands)

    2011-03-15

    The feasibility of the sorption enhanced water gas shift (SEWGS) process under sour conditions is shown. The sour-SEWGS process constitutes a second generation pre-combustion carbon capture technology for the application in an IGCC. As a first critical step, the suitability of a K2CO3 promoted hydrotalcite-based CO2 sorbent is demonstrated by means of adsorption and regeneration experiments in the presence of 2000 ppm H2S. In multiple cycle experiments at 400C and 5 bar, the sorbent displays reversible co-adsorption of CO2 and H2S. The CO2 sorption capacity is not significantly affected compared to sulphur-free conditions. A mechanistic model assuming two different sites for H2S interaction explains qualitatively the interactions of CO2 and H2S with the sorbent. On the type A sites, CO2 and H2S display competitive sorption where CO2 is favoured. The type B sites only allow H2S uptake and may involve the formation of metal sulphides. This material behaviour means that the sour-SEWGS process likely eliminates CO2 and H2S simultaneously from the syngas and that an almost CO2 and H2S-free H2 stream and a CO2 + H2S stream can be produced.

  10. Poly(ionic liquid)/Ionic Liquid Ion-Gels with High "Free" Ionic Liquid Content: Platform Membrane Materials for CO2/Light Gas Separations.

    Science.gov (United States)

    Cowan, Matthew G; Gin, Douglas L; Noble, Richard D

    2016-04-19

    The recycling or sequestration of carbon dioxide (CO2) from the waste gas of fossil-fuel power plants is widely acknowledged as one of the most realistic strategies for delaying or avoiding the severest environmental, economic, political, and social consequences that will result from global climate change and ocean acidification. For context, in 2013 coal and natural gas power plants accounted for roughly 31% of total U.S. CO2 emissions. Recycling or sequestering this CO2 would reduce U.S. emissions by ca. 1800 million metric tons-easily meeting the U.S.'s currently stated CO2 reduction targets of ca. 17% relative to 2005 levels by 2020. This situation is similar for many developed and developing nations, many of which officially target a 20% reduction relative to 1990 baseline levels by 2020. To make CO2 recycling or sequestration processes technologically and economically viable, the CO2 must first be separated from the rest of the waste gas mixture-which is comprised mostly of nitrogen gas and water (ca. 85%). Of the many potential separation technologies available, membrane technology is particularly attractive due to its low energy operating cost, low maintenance, smaller equipment footprint, and relatively facile retrofit integration with existing power plant designs. From a techno-economic standpoint, the separation of CO2 from flue gas requires membranes that can process extremely high amounts of CO2 over a short time period, a property defined as the membrane "permeance". In contrast, the membrane's CO2/N2 selectivity has only a minor effect on the overall cost of some separation processes once a threshold permeability selectivity of ca. 20 is reached. Given the above criteria, the critical properties when developing membrane materials for postcombustion CO2 separation are CO2 permeability (i.e., the rate of CO2 transport normalized to the material thickness), a reasonable CO2/N2 selectivity (≥20), and the ability to be processed into defect-free thin

  11. FUZZY INFERENCE SYSTEM MODELING FOR BED ACTIVE CARBON RE-GENERATION PROCESS (CO2 GAS FACTORY CASE

    Directory of Open Access Journals (Sweden)

    S. Febriana

    2005-01-01

    Full Text Available Bed active carbon is one of the most important materials that had great impact in determining level of impurities in production of CO2 gas. In this particular factory case, there is unavailability of standard duration time of heating and cooling and steam flow rate for the re-generation process of bed active carbon. The paper discusses the fuzzy inference system for modeling of re-generation process of bed active carbon to find the optimum setting parameter. The fuzzy inference system was build using real historical daily processing data. After validation process, surface plot analysis was performed to find the optimum setting. The result of re-generation parameter setting is 9-10 hours of heating process, 4.66-5.32 hours of cooling process, and 1500-2500 kg/hr of steam flow rate.

  12. Observations of Gas Emissions from Cascade Range Volcanoes (USA) using a Portable Real-Time Sensor Package and Evacuated Flasks

    Science.gov (United States)

    Kelly, P. J.; Werner, C. A.; Evans, W.; Ingebritsen, S.; Tucker, D.

    2012-12-01

    Degassing from most Cascade Range Volcanoes, USA, is characterized by low-temperature hydrothermal emissions. It is important to monitor these emissions as part of a comprehensive monitoring strategy yet access is often difficult and most features are sampled by the USGS only once per year at best. In an effort to increase the sampling frequency of major gas species and in preparation for building permanent, autonomous units, we built a portable sensor package capable of measuring H2O, CO2, SO2, and H2S in volcanic gas plumes. Here we compare results from the portable sensor package with gas analyses from direct samples obtained using a titanium tube and evacuated glass flasks collected at the same time. The sensor package is housed in a small, rugged case, weighs 5 kg, and includes sensors for measuring H2O (0-16 parts per thousand), CO2 (0-5000 ppmv), SO2 (0-100 ppm), and H2S (0-20 ppm) gases. Additional temperature and pressure sensors, a micro air pump, datalogger, and an internal battery are also incorporated. H2O and CO2 are measured using an infrared spectrometer (Licor 840) and sulfur-containing gases are measured using electrochemical sensors equipped with filters to mitigate cross-sensitivities. Data are collected at a 1 Hz sampling rate and can be recorded and displayed in real-time using a netbook computer or can be saved to the onboard datalogger. The data display includes timeseries of H2O, CO2, SO2, and H2S mixing ratios, the four-component bulk composition of the plume, and automated calculation of gas ratios commonly used in volcanic gas monitoring, such as H2O/CO2, CO2/SO2, and CO2/H2S . In the Cascade Range, the sensor package has been tested at Mt. Baker, Mt. St. Helens, Mt. Hood, and in Lassen Volcanic National Park. In each case, the instrument was placed 5 to 30 meters from the fumarole or fumarole field and emissions were sampled for 5 to 30 minutes. No SO2 was detected at any location. At Mt. Hood the sensor package yielded average CO2/H2S

  13. Observation of CH4 and other Non-CO2 Green House Gas Emissions from California

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc L.; Zhao, Chuanfeng; Riley, William J.; Andrews, Arlyn C.

    2009-01-09

    In 2006, California passed the landmark assembly bill AB-32 to reduce California's emissions of greenhouse gases (GHGs) that contribute to global climate change. AB-32 commits California to reduce total GHG emissions to 1990 levels by 2020, a reduction of 25 percent from current levels. To verify that GHG emission reductions are actually taking place, it will be necessary to measure emissions. We describe atmospheric inverse model estimates of GHG emissions obtained from the California Greenhouse Gas Emissions Measurement (CALGEM) project. In collaboration with NOAA, we are measuring the dominant long-lived GHGs at two tall-towers in central California. Here, we present estimates of CH{sub 4} emissions obtained by statistical comparison of measured and predicted atmospheric mixing ratios. The predicted mixing ratios are calculated using spatially resolved a priori CH{sub 4} emissions and surface footprints, that provide a proportional relationship between the surface emissions and the mixing ratio signal at tower locations. The footprints are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. Integral to the inverse estimates, we perform a quantitative analysis of errors in atmospheric transport and other factors to provide quantitative uncertainties in estimated emissions. Regressions of modeled and measured mixing ratios suggest that total CH{sub 4} emissions are within 25% of the inventory estimates. A Bayesian source sector analysis obtains posterior scaling factors for CH{sub 4} emissions, indicating that emissions from several of the sources (e.g., landfills, natural gas use, petroleum production, crops, and wetlands) are roughly consistent with inventory estimates, but livestock emissions are significantly higher than the inventory. A Bayesian 'region' analysis is used to identify spatial variations in CH{sub 4} emissions from 13 sub-regions within California

  14. Emission evaluation of CO 2 and CH4 gases in the selected gas pressure booster station in the Bangestan field of the National Iranian Oil Company

    Directory of Open Access Journals (Sweden)

    Mehdi Ahmadi

    2014-11-01

    Full Text Available Background: Iran is located in the seventh rank in terms of CO2 emissions resulting from the fuel combustion in the world. Gas compressor booster stations, due to the several sources of contaminants, are causing the release of large amounts of CO2 and CH4, which will cause climate change; therefore, estimating the emissions of the gases from oil and gas, different processing units are necessary. Methods: In this study, the emissions factor method, provided by various organizations, was used for determining emissions of CO2 and CH4 from different sources. Results: According to the results obtained, the total amount of CO2 emissions in selected units is from the selected unit and is a significant contribution to the CH4 emissions, so that the whole amount of CO2 emissions is equal to 7739.027 tons per day and the total amount of CH4 emissions is 4 tons per day. Conclusion: Burner has the highest amount of CO2 emissions among the sources of pollutants in the fixed combustion sources; and, the highest emissions of CH4, among the exit gas sources, belong to the process of removing water. Among the exit gas sources-compressors maintenance activities the highest emissions belong to CH4. The amount of CO2 emissions from indirect sources, including electrical equipment in the studied units, are from natural gas fuel which are much more than those from fuel oils for burning. CH4 gas from volatile sources in the gas compressors have the highest emissions compared to other sources.

  15. THERMODYNAMICS ANALYSIS FOR CO2 CAPTURE AND REINJECTION FROM GAS PROCESSING IN AN OFFSHORE OIL AND GAS PRODUCTION PLATFORM

    OpenAIRE

    CAMILA CAMPOS MARIN ROCHA

    2015-01-01

    O presente trabalho apresenta uma análise termodinâmica dos processos de captura e reinjeção de CO2, que se tornaram indispensáveis à produção de óleo e gás nas instalações de petróleo offshore no Brasil desde o início do desenvolvimento dos campos do pré-sal. O petróleo dos reservatórios da camada pré-sal da Bacia de Santos apresenta uma particularidade importante, quando comparado com o petróleo dos campos pós-sal do Brasil. A composição do gás natural do pré-sal apresenta grande teor de CO...

  16. Integrated Mirco-Machined Hydrogen Gas Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Frank DiMeoJr. Ing--shin Chen

    2005-12-15

    The widespread use of hydrogen as both an industrial process gas and an energy storage medium requires fast, selective detection of hydrogen gas. This report discusses the development of a new type of solid-state hydrogen gas sensor that couples novel metal hydride thin films with a MEMS (Micro-Electro-Mechanical System) structure known as a micro-hotplate. In this project, Micro-hotplate structures were overcoated with engineered multilayers that serve as the active hydrogen-sensing layer. The change in electrical resistance of these layers when exposed to hydrogen gas was the measured sensor output. This project focused on achieving the following objectives: (1) Demonstrating the capabilities of micro-machined H2 sensors; (2) Developing an understanding of their performance; (3) Critically evaluating the utility and viability of this technology for life safety and process monitoring applications. In order to efficiently achieve these objectives, the following four tasks were identified: (1) Sensor Design and Fabrication; (2) Short Term Response Testing; (3) Long Term Behavior Investigation; (4) Systems Development. Key findings in the project include: The demonstration of sub-second response times to hydrogen; measured sensitivity to hydrogen concentrations below 200 ppm; a dramatic improvement in the sensor fabrication process and increased understanding of the processing properties and performance relationships of the devices; the development of improved sensing multilayers; and the discovery of a novel strain based hydrogen detection mechanism. The results of this program suggest that this hydrogen sensor technology has exceptional potential to meet the stringent demands of life safety applications as hydrogen utilization and infrastructure becomes more prevalent.

  17. Integrated Mirco-Machined Hydrogen Gas Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Frank DiMeoJr. Ing--shin Chen

    2005-12-15

    The widespread use of hydrogen as both an industrial process gas and an energy storage medium requires fast, selective detection of hydrogen gas. This report discusses the development of a new type of solid-state hydrogen gas sensor that couples novel metal hydride thin films with a MEMS (Micro-Electro-Mechanical System) structure known as a micro-hotplate. In this project, Micro-hotplate structures were overcoated with engineered multilayers that serve as the active hydrogen-sensing layer. The change in electrical resistance of these layers when exposed to hydrogen gas was the measured sensor output. This project focused on achieving the following objectives: (1) Demonstrating the capabilities of micro-machined H2 sensors; (2) Developing an understanding of their performance; (3) Critically evaluating the utility and viability of this technology for life safety and process monitoring applications. In order to efficiently achieve these objectives, the following four tasks were identified: (1) Sensor Design and Fabrication; (2) Short Term Response Testing; (3) Long Term Behavior Investigation; (4) Systems Development. Key findings in the project include: The demonstration of sub-second response times to hydrogen; measured sensitivity to hydrogen concentrations below 200 ppm; a dramatic improvement in the sensor fabrication process and increased understanding of the processing properties and performance relationships of the devices; the development of improved sensing multilayers; and the discovery of a novel strain based hydrogen detection mechanism. The results of this program suggest that this hydrogen sensor technology has exceptional potential to meet the stringent demands of life safety applications as hydrogen utilization and infrastructure becomes more prevalent.

  18. Minimization of steam requirements and enhancement of water-gas shift reaction with warm gas temperature CO2 removal

    Science.gov (United States)

    Siriwardane, Ranjani V; Fisher, II, James C

    2013-12-31

    The disclosure utilizes a hydroxide sorbent for humidification and CO.sub.2 removal from a gaseous stream comprised of CO and CO.sub.2 prior to entry into a water-gas-shift reactor, in order to decrease CO.sub.2 concentration and increase H.sub.2O concentration and shift the water-gas shift reaction toward the forward reaction products CO.sub.2 and H.sub.2. The hydroxide sorbent may be utilized for absorbtion of CO.sub.2 exiting the water-gas shift reactor, producing an enriched H.sub.2 stream. The disclosure further provides for regeneration of the hydroxide sorbent at temperature approximating water-gas shift conditions, and for utilizing H.sub.2O product liberated as a result of the CO.sub.2 absorption.

  19. The Precise Mechanisms of a High-Speed Ultrasound Gas Sensor and Detecting Human-Specific Lung Gas Exchange

    Directory of Open Access Journals (Sweden)

    Hideki Toda

    2012-12-01

    Full Text Available In this paper, we propose and develop a new real‐time human respiration process analysis method using a high‐time‐sampling gas concentration sensor based on ultrasound. A unique point about our proposed gas concentration sensor is its 1 kHz gas concentration sampling speed. This figure could not have been attained by previously proposed gas concentration measurement methods such as InfraRed, semiconductor gas sensors, or GC‐MS, because the gas analysis speeds were a maximum of a few hundred milliseconds. First, we describe the proposed new ultrasound sound speed measurement method and the signal processing, and present the measurement circuit diagram. Next, we analyse the human respiration gas variation patterns of five healthy subjects using a newly developed gas‐mask‐ type respiration sensor. This reveals that the rapid gas exchange from H2O to CO2 contains air specific to the human being. In addition, we also measured medical symptoms in subjects suffering from asthma, hyperventilation and bronchial asthma. The millisecond level high‐speed analysis of the human respiration process will be useful for the next generation of healthcare, rehabilitation and sports science technology.

  20. Experimental Study on Recovery of Carbon Dioxide from CO2-EOR Associated Gas by K2CO3-PZ Mixed Amine Solutions%K2CO3-哌嗪复合溶液脱除CO2驱采出气中CO2的实验研究

    Institute of Scientific and Technical Information of China (English)

    张新军; 李庆领; 陆诗建; 高嵩; 李清方; 张建

    2013-01-01

    Carbon dioxide emission and the use of technology has become the global hotpoint,CO2-enhanced oil recovery technology is widely used at home and abroad.About 40%-50%carbon dioxide overflows with associated gas when it is injected underground.Produced fluid contains a large amount of CO2 and water,resulting in the pipeline and equipment corrosion exacerbate,which bring many problems to the production of oil and gas gathering.Therefore,CO2-EOR associated gas carbon dioxide separation and recovery technology is important to study,in which absorption solvent study is most important.The experiment simulates the CO2-EOR associated gas properties with pressure device,studys K2CO3 and K2CO3-PZ solutions absorption experiments under medium pressure,records the amount of into and out gas at different concentrations of the solution and at different temperatures,pressure,time,which reveals the intrinsic relationship between the absorption rate,absorption capacity and time.Also conducting the rich liquid regeneration experiments at the end of absorption,recording the initial CO2 precipitation temperature,rich liquid regeneration temperature,rich liquid regeneration energy consumption and regeneration rate before and after regeneration.Focusing on studying the main characteristics of absorption and desorption,the ratio of the concentration of 30% K2CO3 +3%PZ solution is optimal binary complex solution,which has a better value for scientific research and industrial applications prospects in CO2-EOR associated gas field of carbon capture.%CO2被注入油层后,约有40%~50%(体积分数)随着油田采出液伴生气溢出,采出液中含有大量CO2及水,针对脱除CO2驱采出气中CO2开展实验模拟研究,采用耐压实验装置模拟CO2驱采出伴生气特性,结合胜利油田CO2驱现场实际情况,在中压条件下对碳酸钾及其与哌嗪的复合溶液进行了实验研究,记录不同浓度溶液在不同温度、压力、时间下的进出气

  1. A dynamic leaf gas-exchange strategy is conserved in woody plants under changing ambient CO2: evidence from carbon isotope discrimination in paleo and CO2 enrichment studies

    Science.gov (United States)

    Voelker, Steven L.; Brooks, J. Renée; Meinzer, Frederick C.; Anderson, Rebecca D.; Bader, Martin K.-F.; Battipaglia, Giovanna; Becklin, Katie M.; Beerling, David; Bert, Didier; Betancourt, Julio L.; Dawson, Todd E.; Domec, Jean-Christophe; Guyette, Richard P.; Körner, Christian; Leavitt, Steven W.; Linder, Sune; Marshall, John D.; Mildner, Manuel; Ogée, Jérôme; Panyushkina, Irina P.; Plumpton, Heather J.; Pregitzer, Kurt S.; Saurer, Matthias; Smith, Andrew R.; Siegwolf, Rolf T.W.; Stambaugh, Michael C.; Talhelm, Alan F.; Tardif, Jacques C.; Van De Water, Peter K.; Ward, Joy K.; Wingate, Lisa

    2016-01-01

    Rising atmospheric [CO2], ca, is expected to affect stomatal regulation of leaf gas-exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water, and nutrient cycling of forests. Researchers have proposed various strategies for stomatal regulation of leaf gas-exchange that include maintaining a constant leaf internal [CO2], ci, a constant drawdown in CO2(ca − ci), and a constant ci/ca. These strategies can result in drastically different consequences for leaf gas-exchange. The accuracy of Earth systems models depends in part on assumptions about generalizable patterns in leaf gas-exchange responses to varying ca. The concept of optimal stomatal behavior, exemplified by woody plants shifting along a continuum of these strategies, provides a unifying framework for understanding leaf gas-exchange responses to ca. To assess leaf gas-exchange regulation strategies, we analyzed patterns in ci inferred from studies reporting C stable isotope ratios (δ13C) or photosynthetic discrimination (∆) in woody angiosperms and gymnosperms that grew across a range of ca spanning at least 100 ppm. Our results suggest that much of the ca-induced changes in ci/ca occurred across ca spanning 200 to 400 ppm. These patterns imply that ca − ci will eventually approach a constant level at high ca because assimilation rates will reach a maximum and stomatal conductance of each species should be constrained to some minimum level. These analyses are not consistent with canalization toward any single strategy, particularly maintaining a constant ci. Rather, the results are consistent with the existence of a broadly conserved pattern of stomatal optimization in woody angiosperms and gymnosperms. This results in trees being profligate water users at low ca, when additional water loss is small for each unit of C gain, and increasingly water-conservative at high ca, when photosystems are saturated and water loss is large for each unit C gain.

  2. CO 2 and H 2O gas exchange of a triticale field: I. Leaf level porometry and upscaling to canopy level

    Science.gov (United States)

    Busch, J.; Lösch, R.; Meixner, F. X.; Ammann, C.

    1996-05-01

    Within the frame of an extended field experiment the CO 2 and H 2O gas exchange between a triticale field and the atmosphere was measured during the period between heading and harvest in the summer of 1995. Diurnal courses of H 2O loss, CO 2 gain and leaf conductance were obtained together with microclimatic parameters for leaves of different insertion levels. Patterns of dependence of leaf gas exchange on microclimatic conditions were determined. Based on the results of porometric measurements and crop structural parameters (LAI) gas exchange was scaled up to canopy level.

  3. A single gas chromatograph for accurate atmospheric mixing ratio measurements of CO2, CH4, N2O, SF6 and CO

    NARCIS (Netherlands)

    van der Laan, S.; Neubert, R. E. M.; Meijer, H. A. J.; Simpson, W.R.

    2009-01-01

    We present an adapted gas chromatograph capable of measuring simultaneously and semi-continuously the atmospheric mixing ratios of the greenhouse gases CO2, CH4, N2O and SF6 and the trace gas CO with high precision and long-term stability. The novelty of our design is that all species are measured

  4. A single gas chromatograph for accurate atmospheric mixing ratio measurements of CO2, CH4, N2O, SF6 and CO

    NARCIS (Netherlands)

    van der Laan, S.; Neubert, R. E. M.; Meijer, H. A. J.; Simpson, W.R.

    2009-01-01

    We present an adapted gas chromatograph capable of measuring simultaneously and semi-continuously the atmospheric mixing ratios of the greenhouse gases CO2, CH4, N2O and SF6 and the trace gas CO with high precision and long-term stability. The novelty of our design is that all species are measured w

  5. Comparative Study of Molecular Basket Sorbents Consisting of Polyallylamine and Polyethylenimine Functionalized SBA-15 for CO2 Capture from Flue Gas.

    Science.gov (United States)

    Wang, Xiaoxing; Wang, Dongxiang; Song, Chunshan

    2017-09-20

    Polyallylamine (PAA)-based molecular basket sorbents (MBS) have been studied for CO2 capture in comparison with polyethylenimine (PEI)-based MBS. The characterizations showed that PAA (Mn=15,000) is more rigid and has more steric hindrance inside SBA-15 pores than PEI due mainly to its different polymer structure. The effects of temperature and PAA loadings on the CO2 capacity of PAA/SBA-15 were examined by TGA using 100% CO2 gas stream and compared to PEI/SBA-15. The capacity increased with temperature and the optimum capacity of 88 mg-CO2/g-sorb was obtained at 140 C for PAA(50)/SBA-15; while the optimum temperature was 75 and 90 C for PEI-I(50)/SBA-15 (PEI-I, Mn=423) and PEI-II(50)/SBA-15 (PEI-II, Mn=25,000), respectively. The capacity initially increased with the increase of PAA loading and then dropped at high amine contents, due to the increased diffusion barrier. The highest CO2 capacity of 109 mg-CO2/g-sorb was obtained at PAA loading of 65 wt%, while PAA(50)/SBA-15 gave the best amine efficiency of 0.23 mol-CO2/mol-N. The effect of moisture was examined in the fixed-bed flow system with simulated flue gas containing 15% CO2 and 4.5% O2 in N2, which showed that the presence of moisture significantly enhanced CO2 sorption over PAA(50)/SBA-15 and greatly improved its cyclic stability and regenerability. Compared to PEI/SBA-15, PAA/SBA-15 possesses a better thermal stability and higher resistance to oxidative degradation, however its CO2 sorption rate was much slower. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Highly CO2-Selective Gas Separation Membranes Based on Segmented Copolymers of Poly(Ethylene oxide) Reinforced with Pentiptycene-Containing Polyimide Hard Segments.

    Science.gov (United States)

    Luo, Shuangjiang; Stevens, Kevin A; Park, Jae Sung; Moon, Joshua D; Liu, Qiang; Freeman, Benny D; Guo, Ruilan

    2016-01-27

    Poly(ethylene oxide) (PEO)-containing polymer membranes are attractive for CO2-related gas separations due to their high selectivity toward CO2. However, the development of PEO-rich membranes is frequently challenged by weak mechanical properties and a high crystallization tendency of PEO that hinders gas transport. Here we report a new series of highly CO2-selective, amorphous PEO-containing segmented copolymers prepared from commercial Jeffamine polyetheramines and pentiptycene-based polyimide. The copolymers are much more mechanically robust than the nonpentiptycene containing counterparts due to the molecular reinforcement mechanism of supramolecular chain threading and interlocking interactions induced by the pentiptycene structures, which also effectively suppresses PEO crystallization leading to a completely amorphous structure even at 60% PEO weight content. Membrane transport properties are sensitively affected by both PEO weight content and PEO chain length. A nonlinear correlation between CO2 permeability with PEO weight content was observed due to the competition between solubility and diffusivity contributions, whereby the copolymers change from being size-selective to solubility-selective when PEO content reaches 40%. CO2 selectivities over H2 and N2 increase monotonically with both PEO content and chain length, indicating strong CO2-philicity of the copolymers. The copolymer film with the longest PEO sequence (PEO2000) and highest PEO weight content (60%) showed a measured CO2 pure gas permeability of 39 Barrer, and ideal CO2/H2 and CO2/N2 selectivities of 4.1 and 46, respectively, at 35 °C and 3 atm, making them attractive for hydrogen purification and carbon capture.

  7. 黑59区块回注气驱 CO2浓度优选%Optimization of the CO2 concentration for gas reinjection flooding in HEI-59 oil-field

    Institute of Scientific and Technical Information of China (English)

    陈晓明; 廖新维; 赵晓亮; 崔灿; 叶恒; 王牧

    2015-01-01

    Some of domestic oil fields are in the tertiary EOR phase .Carbon dioxide drive is an environmental friendly ,low carbon emission and high economic efficiency EOR method .The technique of gas reinjection ,as extension of Carbon dioxide drive tech ,the determination of the components is of great significance to the field oil recovery′s improvement .According to Song Liao Basin′s reservoir characteristics ,methods of experimental analysis and theoretical studies were combined .Phase behavior of reinjection gas was studied .Reinjection gas compo‐sition′s impact on the minimum miscibility pressure (MMP) was analyzed .Oil displacement efficiency characteristics under different CO2 purity were researched .Technical indicators of gas injection EOR were determined through combination of reservoir engineering and numer‐ical simulation methods .The result shows that when the concentration ratio of CO2 in rein‐jection gas is greater than 93% ,HEI‐59 reaches an optimal displacement characteristics .%国内部分油田进入了三次采油期。采用CO2驱油提高采收率,具有低碳环保、经济高效等优势,已经得到了推广应用。回注气驱油技术作为CO2驱替技术的一个延伸,其组分的确定对矿场提高采收率具有十分重要的意义。本文针对松辽盆地的油藏特征,进行了细管实验分析和数值模拟研究,分析了回注气组成对最小混相压力的影响以及不同CO2纯度下的驱油效率特征。同时,应用油藏工程方法,确定了回注气提高采收率的工程技术指标,为矿场回注气的高效开发提供技术参考。实验分析和数值模拟结果均表明,黑59区块回注气C O 2浓度比例不低于93%时,驱油效果最佳。

  8. 有机胺溶液吸收燃煤烟气中CO2的实验研究%Experimental Study on CO2 Absorption in Coal Fired Flue Gas with Organic Amine Solution

    Institute of Scientific and Technical Information of China (English)

    张亚萍

    2016-01-01

    The organic amine method was one of the most effective technology for flue gas CO2 capture. In this paper,the performances of absorbing and desorbing CO2 by MEA, DETA, PZ and PG were studied, and the activation effects of MEA as main absorber and PZ, PG, and DETA as three activators were researched. The results showed that the CO2 absorption rate of all absorbents decreased with the increase of the reaction time, and the regeneration rate of rich liquid enhanced with the increase of desorption temperature. The CO2 absorption capacities of single absorbent were DETA>PZ>MEA>PG, degeneration capacities were PG>PZ>MEA (or DETA), these solutions should be mixed to achieve the best results in absorption and desorption. PZ had the best activation effect when MEA was the main absorbent and the molar ratio of MEA-PZ was 0.7:0.3, the absorbent could better meet the production requirements.%有机胺法是最有效的燃煤烟气CO2捕集技术之一,本文对MEA、DETA、PZ、PG这4种有机胺溶液吸收与解吸CO2的性能进行研究,并以MEA为主体吸收剂,添加PZ、PG及DETA这3种活化剂,分别研究其活化效果。结果表明,各种吸收剂对CO2的吸收速率随反应时间增加而降低,富液再生率随解吸温度提高而增大;单一吸收剂对CO2的吸收能力DETA>PZ>MEA>PG,解吸能力PG>PZ>MEA(或DETA);为达到吸收与解吸的平衡,需将它们复配使用。以MEA为主体吸收剂,添加PZ活化效果最好,MEA-PZ摩尔比为0.7∶0.3时,能较好地满足生产要求。

  9. VARIASI SERAPAN KARBONDIOKSIDA (CO2 JENIS-JENIS POHON DI “ECOPARK”, CIBINONG DAN KAITANNYA DENGAN POTENSI MITIGASI GAS RUMAH KACA

    Directory of Open Access Journals (Sweden)

    Nuril Hidayati

    2013-01-01

    Full Text Available This research aims to assess the contribution of biological diversity in CO2 absorption by analyzing the physiological characteristics (CO2 absorption, transpiration, stomatal conductance, leaf chlorophyll content of tree species in a conservation area of “Ecopark”, Cibinong. The results were meant to provide information on CO2 absorption of some tree species suitable for revegetation. The results showed that there was a wide range of variation of CO2 assimilation rate among tree species. The overall CO2 assimilation rate ranged from 2.86 to 16.45  µmolm-2s-1. The highest CO2 absorption was Pometia pinnata (16.45  molm-2s-1, followed by Garcinia xanthochymus (11.40 µmolm-2s-1, Syzygium polyanthum (10.99 µmolm-2s-1, Syzygium polycepaliodes (10.89 µmolm-2s-1, and Palaquium obtusifolium (10.41 µmolm-2s-1. Transpiration rate was recorded between  1.29 mmolm-2s-1 (Maniltoa grandiflora  and 7.85 mmolm-2s-1 (Euphoria longan. The rate of CO2 assimilation was affected by solar radiation and thus the quantum leaf (Q leaf, stomatal conductance, as well as leaf chlorophyll content. Trees species that have characteristics of high CO2 absortion and efficient in maintaining water balance (low transpiration rate, are suitable for green house gas mitigation.  

  10. Development of Fly Ash Derived Sorbents to Capture CO2 from Flue Gas of Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    M. Mercedes Maroto-Valer; John M. Andresen; Yinzhi Zhang; Zhe Lu

    2003-12-31

    This research program focused on the development of fly ash derived sorbents to capture CO{sub 2} from power plant flue gas emissions. The fly ash derived sorbents developed represent an affordable alternative to existing methods using specialized activated carbons and molecular sieves, that tend to be very expensive and hinder the viability of the CO{sub 2} sorption process due to economic constraints. Under Task 1 'Procurement and characterization of a suite of fly ashes', 10 fly ash samples, named FAS-1 to -10, were collected from different combustors with different feedstocks, including bituminous coal, PRB coal and biomass. These samples presented a wide range of LOI value from 0.66-84.0%, and different burn-off profiles. The samples also spanned a wide range of total specific surface area and pore volume. These variations reflect the difference in the feedstock, types of combustors, collection hopper, and the beneficiation technologies the different fly ashes underwent. Under Task 2 'Preparation of fly ash derived sorbents', the fly ash samples were activated by steam. Nitrogen adsorption isotherms were used to characterize the resultant activated samples. The cost-saving one-step activation process applied was successfully used to increase the surface area and pore volume of all the fly ash samples. The activated samples present very different surface areas and pore volumes due to the range in physical and chemical properties of their precursors. Furthermore, one activated fly ash sample, FAS-4, was loaded with amine-containing chemicals (MEA, DEA, AMP, and MDEA). The impregnation significantly decreased the surface area and pore volume of the parent activated fly ash sample. Under Task 3 'Capture of CO{sub 2} by fly ash derived sorbents', sample FAS-10 and its deashed counterpart before and after impregnation of chemical PEI were used for the CO{sub 2} adsorption at different temperatures. The sample FAS-10 exhibited a CO{sub 2

  11. Recognizing frequency characteristics of gas sensor array

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel method based on independent component analyzing (ICA) in frequency domain to distinguish the frequency characteristics of multi-sensor system is presented. The conditions of this type of ICA are considered and each step of resolving the problem is discussed. For a two gas sensor array, the frequency characteristics including amplitude-frequency and phase-frequency are recognized by this method, and cross-sensitivity between them is also eliminated. From the principle of similarity, the recognition mean square error is no more than 0.085.

  12. Comparison of net CO2 fluxes measured with open- and closed-path infrared gas analyzers in an urban complex environment

    DEFF Research Database (Denmark)

    Järvi, L.; Mammarella, I.; Eugster, W.

    2009-01-01

    and their suitability to accurately measure CO2 exchange in such non-ideal landscape. In addition, this study examined the effect of open-path sensor heating on measured fluxes in urban terrain, and these results were compared with similar measurements made above a temperate beech forest in Denmark. The correlation...

  13. Methods and limitations of 'clumped' CO2 isotope (Delta47) analysis by gas-source isotope ratio mass spectrometry.

    Science.gov (United States)

    Huntington, K W; Eiler, J M; Affek, H P; Guo, W; Bonifacie, M; Yeung, L Y; Thiagarajan, N; Passey, B; Tripati, A; Daëron, M; Came, R

    2009-09-01

    The geochemistry of multiply substituted isotopologues ('clumped-isotope' geochemistry) examines the abundances in natural materials of molecules, formula units or moieties that contain more than one rare isotope (e.g. (13)C(18)O(16)O, (18)O(18)O, (15)N(2), (13)C(18)O(16)O(2) (2-)). Such species form the basis of carbonate clumped-isotope thermometry and undergo distinctive fractionations during a variety of natural processes, but initial reports have provided few details of their analysis. In this study, we present detailed data and arguments regarding the theoretical and practical limits of precision, methods of standardization, instrument linearity and related issues for clumped-isotope analysis by dual-inlet gas-source isotope ratio mass spectrometry (IRMS). We demonstrate long-term stability and subtenth per mil precision in 47/44 ratios for counting systems consisting of a Faraday cup registered through a 10(12) ohm resistor on three Thermo-Finnigan 253 IRMS systems. Based on the analyses of heated CO(2) gases, which have a stochastic distribution of isotopes among possible isotopologues, we document and correct for (1) isotopic exchange among analyte CO(2) molecules and (2) subtle nonlinearity in the relationship between actual and measured 47/44 ratios. External precisions of approximately 0.01 per thousand are routinely achieved for measurements of the mass-47 anomaly (a measure mostly of the abundance anomaly of (13)C-(18)O bonds) and follow counting statistics. The present technical limit to precision intrinsic to our methods and instrumentation is approximately 5 parts per million (ppm), whereas precisions of measurements of heterogeneous natural materials are more typically approximately 10 ppm (both 1 s.e.). These correspond to errors in carbonate clumped-isotope thermometry of +/-1.2 degrees C and +/-2.4 degrees C, respectively.

  14. A high-flux polyimide hollow fiber membrane to minimize footprint and energy penalty for CO2 recovery from flue gas

    KAUST Repository

    Lively, Ryan P.

    2012-12-01

    Using a process-guided approach, a new 6FDA-based polyimide - 6FDA-DAM:DABA(4:1) - has been developed in the form of hollow fiber membranes for CO 2 recovery from post-combustion flue gas streams. Dense film studies on this polymer reveal a CO 2 permeability of 224 Barrers at 40°C at a CO 2 feed pressure of 10psia. The dense films exhibit an ideal CO 2/N 2 permselectivity of 20 at 40°C, which permits their use in a two-step counter-flow/sweep membrane process. Dry-jet, wet-quench, non-solvent-induced phase inversion spinning was used to create defect-free hollow fibers from 6FDA-DAM:DABA(4:1). Membranes with defect-free skin layers, approximately 415nm thick, were obtained with a pure CO 2 permeance of 520GPU at 30°C and an ideal CO 2/N 2 permselectivity of 24. Mixed gas permeation and wet gas permeation are presented for the fibers. The CO 2 permeance in the fibers was reduced by approximately a factor of 2 in feeds with 80% humidity. As a proof-of-concept path forward to increase CO 2 flux, we incorporated microporous ZIF-8 fillers into 6FDA-DAM:DABA(4:1) dense films. Our 6FDA-DAM:DABA(4:1)/ZIF-8 dense film composites (20wt% ZIF-8) had a CO 2 permeability of 550 Barrers and a CO 2/N 2 selectivity of 19 at 35°C. Good adhesion between the ZIF and the 6FDA-DAM:DABA(4:1) matrix was observed. CO 2 capture costs of $27/ton of CO 2 using the current, "non-optimized" membrane are estimated using a custom counterflow membrane model. Hollow fiber membrane modules were estimated to have order-of-magnitude reductions in system footprint relative to spiral-wound modules, thereby making them attractive in current space-constrained coal-fired power stations. © 2012 Elsevier B.V.

  15. 高功率CO2激光焊中He-Ar侧吹气体组分研究%Study on Side Assist Blowing Gas with Different Composition in High Power CO2 Laser Welding

    Institute of Scientific and Technical Information of China (English)

    刘必轩; 李国华; 蔡艳; 吴毅雄

    2011-01-01

    Laser induced plasma can affect the process stability and seam quality in high power CO2 laser welding.As the normal suppression method, pure helium is gradually replaced with He-Ar mixed gas for economical efficiency,especially the He content is more than 50%.The qualified E grade steel seam with 12 mm thickness was welded, when He-Ar ratio was 4:6.Plasma characteristics and its interaction with laser beam were investigated through computational fluid dynamics model for high power CO2 laser welding-induced plasma.%在高功率CO2激光深熔焊中,光致等离子体的抑制是保证熔深、稳定焊接过程的关键技术之一.常用的抑制方法是侧吹氦气,而采用氦氩混合气体可降低生产成本,特别是当氦气含量高于50%时.本文采用氦氩比为4:6的混合气体.对12mm厚船用E级钢板进行高功率CO2激光焊接,通过工艺参数优化实现了稳定的焊接过程,全熔透焊缝的质量达到船级社标准.采用流体力学方法建立了高功率CO2激光焊光致等离子体的物理数学模型,分析了氦氩混合气体侧吹时的等离子体特性及对激光能量的影响.

  16. A Diaminopropane-Appended Metal-Organic Framework Enabling Efficient CO2 Capture from Coal Flue Gas via a Mixed Adsorption Mechanism.

    Science.gov (United States)

    Milner, Phillip J; Siegelman, Rebecca L; Forse, Alexander C; Gonzalez, Miguel I; Runčevski, Tomče; Martell, Jeffrey D; Reimer, Jeffrey A; Long, Jeffrey R

    2017-09-27

    A new diamine-functionalized metal-organic framework comprised of 2,2-dimethyl-1,3-diaminopropane (dmpn) appended to the Mg(2+) sites lining the channels of Mg2(dobpdc) (dobpdc(4-) = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) is characterized for the removal of CO2 from the flue gas emissions of coal-fired power plants. Unique to members of this promising class of adsorbents, dmpn-Mg2(dobpdc) displays facile step-shaped adsorption of CO2 from coal flue gas at 40 °C and near complete CO2 desorption upon heating to 100 °C, enabling a high CO2 working capacity (2.42 mmol/g, 9.1 wt %) with a modest 60 °C temperature swing. Evaluation of the thermodynamic parameters of adsorption for dmpn-Mg2(dobpdc) suggests that the narrow temperature swing of its CO2 adsorption steps is due to the high magnitude of its differential enthalpy of adsorption (Δhads = -73 ± 1 kJ/mol), with a larger than expected entropic penalty for CO2 adsorption (Δsads = -204 ± 4 J/mol·K) positioning the step in the optimal range for carbon capture from coal flue gas. In addition, thermogravimetric analysis and breakthrough experiments indicate that, in contrast to many adsorbents, dmpn-Mg2(dobpdc) captures CO2 effectively in the presence of water and can be subjected to 1000 humid adsorption/desorption cycles with minimal degradation. Solid-state (13)C NMR spectra and single-crystal X-ray diffraction structures of the Zn analogue reveal that this material adsorbs CO2 via formation of both ammonium carbamates and carbamic acid pairs, the latter of which are crystallographically verified for the first time in a porous material. Taken together, these properties render dmpn-Mg2(dobpdc) one of the most promising adsorbents for carbon capture applications.

  17. 温室气体CO2资源化催化转化研究进展%Current status on catalytic conversion of greenhouse gas CO2 to value-added chemicals

    Institute of Scientific and Technical Information of China (English)

    杨烽; 王睿

    2013-01-01

    With the global low carbon economy era commences,the reduction and utilization of greenhouse gas becomes a major concern in the world.The reclamation of greenhouse gas CO2 and the new opportunity it brings in the research area of carbon chemistry will become a new hot spot in the research frontier of green catalysis.In this paper,various typical catalytic reaction pathways for enabling direct conversion of CO2 to useful value-added chemicals were reviewed,including oxidation of saturated hydrocarbon by CO2,synthesis of organic acids and esters with CO2.Furthermore,some comments were made regarding the advantages and disadvantages of the catalysts involved,and their underlying reaction mechanisms of CO2 activation by catalysis.Based on these discussions,future work in this category was proposed.The authors believes that,the task-oriented activation of CO2 is the key factor governing the whole process of its chemical utilization,where suitable catalysts with high activity need to be developed;the exploitation of new reaction media and use of new phase state CO2 may greatly enhance the conversion and selectivity of the reaction and hence deserve further investigation ;as to the direct use of CO2 emitted from different practical sources,it is quite necessary to develop multi-functional catalysts with desirable adsorption-catalysis activity,so as to meet the requirements from different cases ; in addition,the investigation of photocatalysis of CO2,and the characterization and simulation on the process of photosynthesis are beneficial to both the utilization of new energy and the mitigation of greenhouse gas.%随着全球化低碳经济时代的开启,温室气体的减排及利用成为举世关注的焦点,二氧化碳资源化利用及由此形成的新的碳一化学将成为绿色催化研究领域的热点问题.本文综述了二氧化碳资源化催化转化为高附加值化学品的若干反应途径,包括二氧化碳氧化饱和烃类、二氧化碳合成有

  18. A STUDY ON CARBON ISOTOPE OF CO2 AND CH4 IN WESTERN DIENG PLATEU BY GAS CHROMATOGRAPHY- ISOTOPE RATIO MASS SPECTROMETER (GC-IRMS

    Directory of Open Access Journals (Sweden)

    Hanik Humaida

    2010-06-01

    Full Text Available The carbon isotope can be used to evaluate volcanism phenomenon of volcano. The study of carbon isotope of CO2 and CH4 was carried out in western Dieng Plateau by mass-spectrometer. Before analysis, sampel was separated by gas chromatography using a Porapak-Q column and a FID (Flame Ionization Detector detector. The gas was oxidized by copper oxide at 850oC before being ionized in mass-spectrometer for isotope analysis. The CO2 content in Candradimuka crater (-4.10 O/OO, indicated that the gas may be as volcanic gas. The other CO2 from Sumber and western Gua Jimat, had isotope value  of -10.05 and -12.07 O/OO, respectively, indicating contamination from crustal and subduction material. The carbon isotope of CH4 gas from Pancasan village was -63.42 O/OO, that may be categorized as biogenic gas.   Keywords: isotope, CO2, CH4, Dieng.

  19. Gas-phase CO2 subtraction for improved measurements of the organic aerosol mass concentration and oxidation degree by an aerosol mass spectrometer.

    Science.gov (United States)

    Collier, S; Zhang, Q

    2013-12-17

    The Aerodyne aerosol mass spectrometer (AMS) has been widely used for real-time characterization of the size-resolved chemical composition of sub-micrometer aerosol particles. The first step in AMS sampling is the pre-concentration of aerosols while stripping away the gas-phase components, which contributes to the high sensitivity of this instrument. The strength of the instrument lies in particle phase measurement; however, ion signals generated from gas-phase species can influence the interpretation of the particle-phase chemistry data. Here, we present methods for subtracting the varying contributions of gas-phase carbon dioxide (CO2) in the AMS spectra of aerosol particles, which is critical for determining