WorldWideScience

Sample records for water gas

  1. Separation of water through gas hydrate formation

    DEFF Research Database (Denmark)

    Boch Andersen, Torben; Thomsen, Kaj

    2009-01-01

    Gas hydrate is normally recognized as a troublemaker in the oil and gas industry. However, gas hydrate has some interesting possibilities when used in connection with separation of water. Nordic Sugar has investigated the possibility of using gas hydrates for concentration of sugar juice. The goa...... volumes and the needs for high pressure. The process could be interesting for concentration of heat sensitive, high value products......Gas hydrate is normally recognized as a troublemaker in the oil and gas industry. However, gas hydrate has some interesting possibilities when used in connection with separation of water. Nordic Sugar has investigated the possibility of using gas hydrates for concentration of sugar juice. The goal...... of the project was to formulate an alternative separation concept, which can replace the traditional water evaporation process in the sugar production. Work with the separation concept showed that gas hydrates can be used for water separation. The process is not suitable for sugar production because of large...

  2. Recovery of Water from Boiler Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Edward Levy; Harun Bilirgen; Kwangkook Jeong; Michael Kessen; Christopher Samuelson; Christopher Whitcombe

    2008-09-30

    This project dealt with use of condensing heat exchangers to recover water vapor from flue gas at coal-fired power plants. Pilot-scale heat transfer tests were performed to determine the relationship between flue gas moisture concentration, heat exchanger design and operating conditions, and water vapor condensation rate. The tests also determined the extent to which the condensation processes for water and acid vapors in flue gas can be made to occur separately in different heat transfer sections. The results showed flue gas water vapor condensed in the low temperature region of the heat exchanger system, with water capture efficiencies depending strongly on flue gas moisture content, cooling water inlet temperature, heat exchanger design and flue gas and cooling water flow rates. Sulfuric acid vapor condensed in both the high temperature and low temperature regions of the heat transfer apparatus, while hydrochloric and nitric acid vapors condensed with the water vapor in the low temperature region. Measurements made of flue gas mercury concentrations upstream and downstream of the heat exchangers showed a significant reduction in flue gas mercury concentration within the heat exchangers. A theoretical heat and mass transfer model was developed for predicting rates of heat transfer and water vapor condensation and comparisons were made with pilot scale measurements. Analyses were also carried out to estimate how much flue gas moisture it would be practical to recover from boiler flue gas and the magnitude of the heat rate improvements which could be made by recovering sensible and latent heat from flue gas.

  3. Gas Property Demonstrations Using Plastic Water Bottles

    Science.gov (United States)

    Campbell, Dean J.; Bannon, Stephen J.; Gunter, Molly M.

    2011-01-01

    Plastic water bottles are convenient containers for demonstrations of gas properties illustrating Boyle's law, Charles's law, and Avogadro's law. The contents of iron-based disposable hand warmer packets can be used to remove oxygen gas from the air within an unfilled plastic water bottle.

  4. Gas-Water Flow Behavior in Water-Bearing Tight Gas Reservoirs

    Directory of Open Access Journals (Sweden)

    Renyi Cao

    2017-01-01

    Full Text Available Some tight sandstone gas reservoirs contain mobile water, and the mobile water generally has a significant impact on the gas flowing in tight pores. The flow behavior of gas and water in tight pores is different than in conventional formations, yet there is a lack of adequate models to predict the gas production and describe the gas-water flow behaviors in water-bearing tight gas reservoirs. Based on the experimental results, this paper presents mathematical models to describe flow behaviors of gas and water in tight gas formations; the threshold pressure gradient, stress sensitivity, and relative permeability are all considered in our models. A numerical simulator using these models has been developed to improve the flow simulation accuracy for water-bearing tight gas reservoirs. The results show that the effect of stress sensitivity becomes larger as water saturation increases, leading to a fast decline of gas production; in addition, the nonlinear flow of gas phase is aggravated with the increase of water saturation and the decrease of permeability. The gas recovery decreases when the threshold pressure gradient (TPG and stress sensitivity are taken into account. Therefore, a reasonable drawdown pressure should be set to minimize the damage of nonlinear factors to gas recovery.

  5. The gas recovery of water-drive gas reservoirs

    Institute of Scientific and Technical Information of China (English)

    李闽; 李滔; 蒋琼; 杨海; 刘世常

    2015-01-01

    This paper proposes a method for determining the gas recovery of water-drive gas reservoirs. First, the water influx coefficientB in the theoretical formula=(1)/(1B)rggpRR−− is used to determine the influence of the aquifer behavior. According to the theoretical formula, the relationship between the normalized pressurerp and the degree of the reserve recovery gR can be obtained with different values ofB, which can be used to determine the activity level of the aquifer behavior. Second, according to=(1)/(1)ragavapRaE−− (where=1gr/gia−SS), the relationship between the normalized abandonment pressure rap and the ultimate gas recoverygaR can be obtained, as the Agarwal end-point line. The intersection of the above two lines represents the value of the estimated ultimate gas recovery and the normalized abandonment pressurerap. Finally, an evaluation table and a set of demarcation charts are established, with different values ofSgr/Sgi andvaE as well as the water influx coefficientB, which can be used to determine the gas recovery of water-drive gas reservoirs with different activity levels of the aquifer behavior.

  6. Gas and Water Permeability of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.

    2012-11-01

    The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

  7. Treatment of Oil & Gas Produced Water.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Brian P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-02-01

    Production of oil and gas reserves in the New Mexico Four Corners Region results in large volumes of "produced water". The common method for handling the produced water from well production is re-injection in regulatory permitted salt water disposal wells. This is expensive (%7E $5/bbl.) and does not recycle water, an ever increasingly valuable commodity. Previously, Sandia National Laboratories and several NM small business tested pressure driven membrane-filtration techniques to remove the high TDS (total dissolved solids) from a Four Corners Coal Bed Methane produced water. Treatment effectiveness was less than optimal due to problems with pre-treatment. Inadequate pre-treatment allowed hydrocarbons, wax and biological growth to foul the membranes. Recently, an innovative pre-treatment scheme using ozone and hydrogen peroxide was pilot tested. Results showed complete removal of hydrocarbons and the majority of organic constituents from a gas well production water. ACKNOWLEDGEMENTS This report was made possible through funding from the New Mexico Small Business Administration (NMSBA) Program at Sandia National Laboratories. Special thanks to Juan Martinez and Genaro Montoya for guidance and support from project inception to completion. Also, special thanks to Frank McDonald, the small businesses team POC, for laying the ground work for the entire project; Teresa McCown, the gas well owner and very knowledgeable- fantastic site host; Lea and Tim Phillips for their tremendous knowledge and passion in the oil & gas industry.; and Frank Miller and Steve Addleman for providing a pilot scale version of their proprietary process to facilitate the pilot testing.

  8. Air-Water Gas Transfer in Coastal Waters

    Science.gov (United States)

    2016-06-07

    OBJECTIVES In interdisciplinary field experiments the influence of wind forcing, short wind waves, and surfactants on the air-sea gas transfer in coastal...Physicochemical surface conditions ranged from coastal waters with high surfactant concentrations to very clean, deep blue waters close to the Bermuda islands...research project are only the beginning of a new interdisciplinary research area that merges chemistry , applied optics, fluid mechanics, and image

  9. Decomposition of water into highly combustible hydroxyl gas used in ...

    African Journals Online (AJOL)

    Decomposition of water into highly combustible hydroxyl gas used in internal ... of alternative sources of energy that produce less amounts of carbon dioxide. ... The by-product obtained from combustion of this gas is water vapour and oxygen ...

  10. Geochemical evidence of water-soluble gas accumulation in the Weiyuan gas field, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Shengfei Qin

    2016-01-01

    Full Text Available At present, there are several different opinions on the formation process of the Weiyuan gas field in the Sichuan Basin and the source of its natural gas. In view of the fact that the methane carbon isotope of the natural gas in the Weiyuan gas field is abnormally heavy, the geologic characteristics of gas reservoirs and the geochemical characteristics of natural gas were first analyzed. In the Weiyuan gas field, the principal gas reservoirs belong to Sinian Dengying Fm. The natural gas is mainly composed of methane, with slight ethane and trace propane. The gas reservoirs are higher in water saturation, with well preserved primary water. Then, it was discriminated from the relationship of H2S content vs. methane carbon isotope that the heavier methane carbon isotope of natural gas in this area is not caused by thermochemical sulfate reduction (TSR. Based on the comparison of methane carbon isotope in this area with that in adjacent areas, and combined with the tectonic evolution background, it is regarded that the natural gas in the Weiyuan gas field is mainly derived from water-soluble gas rather than be migrated laterally from adjacent areas. Some conclusions are made. First, since methane released from water is carbon isotopically heavier, the water-soluble gas accumulation after degasification results in the heavy methane carbon isotope of the gas produced from Weiyuan gas field. Second, along with Himalayan movement, great uplift occurred in the Weiyuan area and structural traps were formed. Under high temperature and high pressure, the gas dissolved in water experienced decompression precipitation, and the released natural gas accumulated in traps, consequently leading to the formation of Weiyuan gas field. Third, based on calculation, the amount of natural gas released from water which is entrapped in the Weiyuan gas field after the tectonic uplift is basically equal to the proved reserves of this field, confirming the opinion of water

  11. 3D modeling of gas/water distribution in water-bearing carbonate gas reservoirs: the Longwangmiao gas field, China

    Science.gov (United States)

    Ou, Chenghua; Li, ChaoChun; Ma, Zhonggao

    2016-10-01

    A water-bearing carbonate gas reservoir is an important natural gas resource being developed worldwide. Due to the long-term water/rock/gas interaction during geological evolution, complex gas/water distribution has formed under the superposed effect of sedimentary facies, reservoir space facies and gravity difference of fluid facies. In view of these challenges, on the basis of the conventional three-stage modeling method, this paper presents a modelling method controlled by four-stage facies to develop 3D model of a water-bearing carbonate gas reservoir. Key to this method is the reservoir property modelling controlled by two-stage facies, and the fluid property modelling controlled by another two-stage facies. The prerequisite of this method is a reliable database obtained from solid geological investigation. On the basis of illustrating the principles of the modelling method controlled by four-stage facies, this paper further implements systematically modeling of the heterogeneous gas/water distribution of the Longwangmiao carbonate formation in the Moxi-Gaoshiti area, Sichuan basin, China.

  12. Improving the Gas Instantaneous Water Heaters Performances

    Directory of Open Access Journals (Sweden)

    Nasir Kloub

    2005-01-01

    Full Text Available This study presents a study of a theoretical and practical investigation of the gas Instantaneous (Tankless water Heaters performance. The results allow us to obtain realistic values of the control system in the various capacities gaseous flowing water heaters. The objective of this work is to study the operation of the plans in the field of controlling and checking low capacity gaseous flowing water in order to choose the proper plan of the logical values and measures for these equipments that may be used in industrial conditions. Also results of the work proved to be accurate. A design of the control system was made. The results of the practical experiment of the control system were similar to the arithmetic results.

  13. Analysis of Water Features in Gas Leakage Area

    Directory of Open Access Journals (Sweden)

    Liu Huaishan

    2011-01-01

    Full Text Available In a certain frequency range, gas is an effective absorber and scatterer of sound, which changes the compressibility of water, and then changes the speed and frequency of sound. Gas continues rising, deforming, and dissolving. The same bubble of natural gas has different radii at different depths. By analyzing these changes, the resonance frequency of gas bubble, and its impacts on sound wave, characteristics of the influences of gas at different depths on the incident sound wave can be obtained. The main sound features of gas are relevant to the gas size, gas content, velocity, attenuation, resonance frequency, the scattering cross-section, and so forth. Sound models with hydrate and free gas in the water and sediment are established. Through the practical application to actual data, the sound characteristics yielded when the gas (or gas hydrate dissociation escaped the water of seismic data are very clear.

  14. Water vapor and gas transport through PEO PBT block copolymers

    NARCIS (Netherlands)

    Metz, S.J.; Potreck, J.; Mulder, M.H.V.; Wessling, M.

    2002-01-01

    Introduction At the bore well natural gas is saturated with water. Downstream the presence of water may cause: formation of methane hydrates (blocking eventually the pipeline), condensation of water in the pipeline and corrosion effects. A process used for the dehydration of natural gas is glycol ab

  15. Life cycle water consumption for shale gas and conventional natural gas.

    Science.gov (United States)

    Clark, Corrie E; Horner, Robert M; Harto, Christopher B

    2013-10-15

    Shale gas production represents a large potential source of natural gas for the nation. The scale and rapid growth in shale gas development underscore the need to better understand its environmental implications, including water consumption. This study estimates the water consumed over the life cycle of conventional and shale gas production, accounting for the different stages of production and for flowback water reuse (in the case of shale gas). This study finds that shale gas consumes more water over its life cycle (13-37 L/GJ) than conventional natural gas consumes (9.3-9.6 L/GJ). However, when used as a transportation fuel, shale gas consumes significantly less water than other transportation fuels. When used for electricity generation, the combustion of shale gas adds incrementally to the overall water consumption compared to conventional natural gas. The impact of fuel production, however, is small relative to that of power plant operations. The type of power plant where the natural gas is utilized is far more important than the source of the natural gas.

  16. Experimental study of water effects on gas desorption during high-pressure water injection

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-hua; LIU Xian-xin; BI Ye-wu; PU Wen-long

    2011-01-01

    For the question of applying high-pressure water injection to increase gas extraction efficiency by increasing the permeability of water to drive gas action,an independently designed gas desorption experimental measuring device was used under the condition of external solution invasion.The law of water effect on gas desorption was obtained after water invasion through experiment for the first time.The results show that water's later invasion not only can make the quantity of gas desorption greatly reduced,but also can make gas desorption end early.Therefore,when evaluating the applications of high-pressure water injection to increase gas extraction efficiency,we should take water damaging effects on gas desorption into account.

  17. Water vapor and gas transport through polymeric membranes

    NARCIS (Netherlands)

    Metz, S.J.

    2003-01-01

    Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air). Dep

  18. Water vapor and Gas Transport through Polymeric Membranes

    NARCIS (Netherlands)

    Metz, S.J.

    2003-01-01

    Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air).

  19. Electrochemical Cell with Improved Water or Gas Management

    Science.gov (United States)

    Smith, William F. (Inventor); McElroy, James F. (Inventor); LaGrange, Jay W. (Inventor)

    2015-01-01

    An electrochemical cell having a water/gas porous separator prepared from a polymeric material and one or more conductive cell components that pass through, or are located in close proximity to, the water/gas porous separator, is provided. The inventive cell provides a high level of in-cell electrical conductivity.

  20. WATER BREAKTHROUGH SIMULATION IN NATURALLY FRACTURED GAS RESERVOIRS WITH WATER DRIVE

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lie-hui; FENG Guo-qing; LI xiao-ping; LI Yun

    2005-01-01

    In the fractured water drive reservoirs of China, because of the complex geological conditions, almost all the active water invasions appear to be water breakthrough along fractures, especially along macrofractures. These seal the path of gas flow, thus the remaining gas in the pores mixes into water, and leads to gas-water interactive distribution in the fractured gas reservoir. These complicated fractured systems usually generate some abnormal flowing phenomena such as the crestal well produces water while the downdip well in the same gas reservoir produces gas, or the same gas well produces water intermittently. It is very difficult to explain these phenomena using existing fracture models because of their simple handling macrofractures without considering nonlinear flowing in the macrofractures and the low permeability matrix. Therefore, a nonlinear combined-flowing multimedia simulation model was successfully developed in this paper by introducing the equations of macrofractures and considering nonlinear flow in the macrofractures and the matrix. This model was then applied to actual fractured bottom water gas fields. Sensitivity studies of gas production by water drainage in fractured gas reservoirs were completed and the effect of different water drainage intensity and ways on actual gas production using this model were calculated. This model has been extensively used to predict the production performance in various fractured gas fields and proven to be reliable.

  1. On the Law Right of the Gas Water of Water Resources

    Institute of Scientific and Technical Information of China (English)

    Liu Shujun

    2007-01-01

    With the development of science and technology,there searches and application of water resources including the gas water have been constantly developed.Through an analysis on the flaws of the water right theory,and by executing reconstruction and renewal of the theory and system of water fight in modern society,the water right position of the gas water will be established,leading to the maturity of the whole law effectiveness and substantial results of water right.

  2. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Davis Energy Group, Davis, CA (United States); Weitzel, Elizabeth [Davis Energy Group, Davis, CA (United States); Backman, Christine [Davis Energy Group, Davis, CA (United States)

    2017-02-28

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  3. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-02-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  4. The role of water in gas hydrate dissociation

    Science.gov (United States)

    Circone, S.; Stern, L.A.; Kirby, S.H.

    2004-01-01

    When raised to temperatures above the ice melting point, gas hydrates release their gas in well-defined, reproducible events that occur within self-maintained temperature ranges slightly below the ice point. This behavior is observed for structure I (carbon dioxide, methane) and structure II gas hydrates (methane-ethane, and propane), including those formed with either H2O- or D2O-host frameworks, and dissociated at either ambient or elevated pressure conditions. We hypothesize that at temperatures above the H2O (or D2O) melting point: (1) hydrate dissociation produces water + gas instead of ice + gas, (2) the endothermic dissociation reaction lowers the temperature of the sample, causing the water product to freeze, (3) this phase transition buffers the sample temperatures within a narrow temperature range just below the ice point until dissociation goes to completion, and (4) the temperature depression below the pure ice melting point correlates with the average rate of dissociation and arises from solution of the hydrate-forming gas, released by dissociation, in the water phase at elevated concentrations. In addition, for hydrate that is partially dissociated to ice + gas at lower temperatures and then heated to temperatures above the ice point, all remaining hydrate dissociates to gas + liquid water as existing barriers to dissociation disappear. The enhanced dissociation rates at warmer temperatures are probably associated with faster gas transport pathways arising from the formation of water product.

  5. Produced water management - clean and safe oil and gas production

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference contains 22 presentations on topics within pollution sources and abatement, discharge reductions, water analysis and monitoring, water production, treatment and injection, enhanced recovery, condensate water, produced water markets, separation technologies for oil/gas/condensate and water, oil removal from solids, environmental risks of oil and gas production and environmental impacts on ecosystems and fisheries. Some oil field case histories are presented. The main focus is on the northern areas such as the North Sea, the north Atlantic Ocean and the Barents Sea, and technological aspects (tk)

  6. Relative water and gas permeability for gas production from hydrate-bearing sediments

    Science.gov (United States)

    Mahabadi, Nariman; Jang, Jaewon

    2014-06-01

    water and gas permeability equations are important for estimating gas and water production from hydrate-bearing sediments. However, experimental or numerical study to determine fitting parameters of those equations is not available in the literature. In this study, a pore-network model is developed to simulate gas expansion and calculate relative water and gas permeability. Based on the simulation results, fitting parameters for modified Stone equation are suggested for a distributed hydrate system where initial hydrate saturations range from Sh = 0.1 to 0.6. The suggested fitting parameter for relative water permeability is nw ≈ 2.4 regardless of initial hydrate saturation while the suggested fitting parameter for relative gas permeability is increased from ng = 1.8 for Sh = 0.1 to ng = 3.5 for Sh = 0.6. Results are relevant to other systems that experience gas exsolution such as pockmark formation due to sea level change, CO2 gas formation during geological CO2 sequestration, and gas bubble accumulation near the downstream of dams.

  7. Attenuating water hammer pressure by means of gas storage tank

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The basic equations for computing the volume of gas storage tank were derived from the principles of attenuating water hammer pressure. Verifications using experiments indicate that the proposed equation can provide a fare precision in the predictions. By using the model of solid-liquid two-phase flow, the gas storage tank, pressure-relief valves and slow-closure reverse-control valves were compared with practical engineering problems, and the functions of gas storage tank in attenuating water hammer pressure were further investigated.

  8. Methane storage in dry water gas hydrates.

    Science.gov (United States)

    Wang, Weixing; Bray, Christopher L; Adams, Dave J; Cooper, Andrew I

    2008-09-03

    Dry water stores 175 v(STP)/v methane at 2.7 MPa and 273.2 K in a hydrate form which is close to the Department of Energy volumetric target for methane storage. Dry water is a silica-stabilized free-flowing powder (95% wt water), and fast methane uptakes were observed (90% saturation uptake in 160 min with no mixing) as a result of the relatively large surface-to-volume ratio of this material.

  9. Equilibrium water content measurements for acid gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, R.A.; Fitzpatrick, E.; Bernard, F.; Wan, H.H.; Lesage, K.L.; Davis, P.M.; Clark, P.D. [Alberta Sulphur Research Ltd., Calgary, AB (Canada)

    2009-07-01

    An accurate understanding of acid gas and water equilibrium is needed in order to design safe acid gas injection facilities. This paper described a joint industry project conducted to measure the water content of acid gas mixtures under moderate pressures and temperatures. The study has accumulated over 160 data points. Techniques used to obtain the measurements have included visual dew point determination for liquid acid gas and hydrates; the equilibration of samples in stirred autoclaves; basic static equilibration cells; and an isolated floating piston with a micro-sampler used to inject gaseous and liquid acid gas phases. As a result of the project, a high pressure micro-sampling technique has been developed to pressure limits of 1000 bar. 33 refs., 2 tabs., 10 figs.

  10. Water coning mechanism in Tarim fractured sandstone gas reservoirs

    Institute of Scientific and Technical Information of China (English)

    沈伟军; 刘晓华; 李熙喆; 陆家亮

    2015-01-01

    The problem of water coning into the Tarim fractured sandstone gas reservoirs becomes one of the major concerns in terms of productivity, increased operating costs and environmental effects. Water coning is a phenomenon caused by the imbalance between gravity and viscous forces around the completion interval. There are several controllable and uncontrollable parameters influencing this problem. In order to simulate the key parameters affecting the water coning phenomenon, a model was developed to represent a single well with an underlying aquifer using the fractured sandstone gas reservoir data of the A-Well in Dina gas fields. The parametric study was performed by varying six properties individually over a representative range. The results show that matrix permeability, well penetration (especially fracture permeability), vertical-to-horizontal permeability ratio, aquifer size and gas production rate have considerable effect on water coning in the fractured gas reservoirs. Thus, investigation of the effective parameters is necessary to understand the mechanism of water coning phenomenon. Simulation of the problem helps to optimize the conditions in which the breakthrough of water coning is delayed.

  11. On the use of Rotary Gas/gas Heat Exchangers as a Novel Integration Option for Heat and Water Management in Exhaust Gas Recycling Gas Turbine Plants

    OpenAIRE

    Herraiz, Laura; Hogg, Dougal; Cooper, Jim; Gibbins, Jon; Lucquiaud, Mathieu

    2014-01-01

    This work is a first-of-a-kind feasibility study investigating technology options with gas/gas rotary heat exchangers for the water management in the integration of Natural Gas Combined Cycle (NGCC) plants with post-combustion carbon capture, with and without exhaust gas recirculation (EGR). A range of configurations are examined for wet and dry cooling of the flue gas entering a post- combustion capture (PCC) absorption system, and regenerative heating of the CO2-depleted flue gas prior to t...

  12. Impact of shale gas development on regional water quality.

    Science.gov (United States)

    Vidic, R D; Brantley, S L; Vandenbossche, J M; Yoxtheimer, D; Abad, J D

    2013-05-17

    Unconventional natural gas resources offer an opportunity to access a relatively clean fossil fuel that could potentially lead to energy independence for some countries. Horizontal drilling and hydraulic fracturing make the extraction of tightly bound natural gas from shale formations economically feasible. These technologies are not free from environmental risks, however, especially those related to regional water quality, such as gas migration, contaminant transport through induced and natural fractures, wastewater discharge, and accidental spills. We review the current understanding of environmental issues associated with unconventional gas extraction. Improved understanding of the fate and transport of contaminants of concern and increased long-term monitoring and data dissemination will help manage these water-quality risks today and in the future.

  13. Thermodynamic Modeling of Natural Gas Systems Containing Water

    DEFF Research Database (Denmark)

    Karakatsani, Eirini K.; Kontogeorgis, Georgios M.

    2013-01-01

    with a heavy phase were previously obtained using cubic plus association (CPA) coupled with a solid phase model in the case of hydrates, for the binary systems of water–methane and water–nitrogen and a few natural gas mixtures. In this work, CPA is being validated against new experimental data, both water...... content and phase equilibrium data, and solid model parameters are being estimated for four natural gas main components (methane, ethane, propane, and carbon dioxide). Different tests for the solid model parameters are reported, including vapor-hydrate-equilibria (VHE) and liquid-hydrate-equilibria (LHE......As the need for dew point specifications remains very urgent in the natural gas industry, the development of accurate thermodynamic models, which will match experimental data and will allow reliable extrapolations, is needed. Accurate predictions of the gas phase water content in equilibrium...

  14. Gas storage in "dry water" and "dry gel" clathrates.

    Science.gov (United States)

    Carter, Benjamin O; Wang, Weixing; Adams, Dave J; Cooper, Andrew I

    2010-03-02

    "Dry water" (DW) is a free-flowing powder prepared by mixing water, hydrophobic silica particles, and air at high speeds. We demonstrated recently that DW can be used to dramatically enhance methane uptake rates in methane gas hydrate (MGH). Here, we expand on our initial work, demonstrating that DW can be used to increase the kinetics of formation of gas clathrates for gases other than methane, such as CO(2) and Kr. We also show that the stability of the system toward coalescence can be increased via the inclusion of a gelling agent to form a "dry gel", thus dramatically improving the recyclability of the material. For example, the addition of gellan gum allows effective reuse over at least eight clathration cycles without the need for reblending. DW and its "dry gel" modification may represent a potential platform for recyclable gas storage or gas separation on a practicable time scale in a static, unmixed system.

  15. Increased stray gas abundance in a subset of drinking water wells near Marcellus shale gas extraction.

    Science.gov (United States)

    Jackson, Robert B; Vengosh, Avner; Darrah, Thomas H; Warner, Nathaniel R; Down, Adrian; Poreda, Robert J; Osborn, Stephen G; Zhao, Kaiguang; Karr, Jonathan D

    2013-07-09

    Horizontal drilling and hydraulic fracturing are transforming energy production, but their potential environmental effects remain controversial. We analyzed 141 drinking water wells across the Appalachian Plateaus physiographic province of northeastern Pennsylvania, examining natural gas concentrations and isotopic signatures with proximity to shale gas wells. Methane was detected in 82% of drinking water samples, with average concentrations six times higher for homes wells (P = 0.0006). Ethane was 23 times higher in homes wells (P = 0.0013); propane was detected in 10 water wells, all within approximately 1 km distance (P = 0.01). Of three factors previously proposed to influence gas concentrations in shallow groundwater (distances to gas wells, valley bottoms, and the Appalachian Structural Front, a proxy for tectonic deformation), distance to gas wells was highly significant for methane concentrations (P = 0.007; multiple regression), whereas distances to valley bottoms and the Appalachian Structural Front were not significant (P = 0.27 and P = 0.11, respectively). Distance to gas wells was also the most significant factor for Pearson and Spearman correlation analyses (P wells was the only statistically significant factor (P wells have drinking water contaminated with stray gases.

  16. Zero Discharge Water Management for Horizontal Shale Gas Well Development

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Jennifer Hause; Raymond Lovett; David Locke Harry Johnson; Doug Patchen

    2012-03-31

    Hydraulic fracturing technology (fracking), coupled with horizontal drilling, has facilitated exploitation of huge natural gas (gas) reserves in the Devonian-age Marcellus Shale Formation (Marcellus) of the Appalachian Basin. The most-efficient technique for stimulating Marcellus gas production involves hydraulic fracturing (injection of a water-based fluid and sand mixture) along a horizontal well bore to create a series of hydraulic fractures in the Marcellus. The hydraulic fractures free the shale-trapped gas, allowing it to flow to the well bore where it is conveyed to pipelines for transport and distribution. The hydraulic fracturing process has two significant effects on the local environment. First, water withdrawals from local sources compete with the water requirements of ecosystems, domestic and recreational users, and/or agricultural and industrial uses. Second, when the injection phase is over, 10 to 30% of the injected water returns to the surface. This water consists of flowback, which occurs between the completion of fracturing and gas production, and produced water, which occurs during gas production. Collectively referred to as returned frac water (RFW), it is highly saline with varying amounts of organic contamination. It can be disposed of, either by injection into an approved underground injection well, or treated to remove contaminants so that the water meets the requirements of either surface release or recycle use. Depending on the characteristics of the RFW and the availability of satisfactory disposal alternatives, disposal can impose serious costs to the operator. In any case, large quantities of water must be transported to and from well locations, contributing to wear and tear on local roadways that were not designed to handle the heavy loads and increased traffic. The search for a way to mitigate the situation and improve the overall efficiency of shale gas production suggested a treatment method that would allow RFW to be used as make

  17. Mechanisms and solubility equations of gas dissolving in water

    Institute of Scientific and Technical Information of China (English)

    付晓泰; 王振平; 卢双舫

    1996-01-01

    The two mechanisms of gas dissolving in water, interstice filling and aquation, are proposed. General equations of gas solubility have been deduced from the mechanisms and experimental observations. Dependence of Henry’s coefficient on temperature, pressure, aquation equilibrium constant and gas molecular wlume is discussed. The theoretical equations were verified by experimental data, which shows that the theoretical results of the solubility of methane are in good agreement with the experimental data in the range of 20 -160℃ and under a pressure of less than 60 MPa.

  18. Prediction of natural gas hydrate formation region in wellbore during deep- water gas well testing

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-yuan; SUN Bao-jiang; WANG Xue-rui; ZHANG Zhen-nan

    2014-01-01

    Wellbore temperature field equations are established with considerations of the enthalpy changes of the natural gas during the deep-water gas well testing. A prediction method for the natural gas hydrate formation region during the deep-water gas well testing is proposed, which combines the wellbore temperature field equations, the phase equilibrium conditions of the natural gas hydrate formation and the calculation methods for the pressure field. Through the sensitivity analysis of the parameters that affect the hydrate formation region, it can be concluded that during the deep-water gas well testing, with the reduction of the gas production rate and the decrease of the geothermal gradient, along with the increase of the depth of water, the hydrate formation region in the wellbore enlarges, the hydrate formation regions differ with different component contents of natural gases, as compared with the pure methane gas, with the increase of ethane and propane, the hydrate formation region expands, the admixture of inhibitors, the type and the concentrations of which can be optimized through the method proposed in the paper, will reduce the hydrate formation region, the throttling effect will lead to the abrupt changes of temperature and pressure, which results in a variation of the hydrate formation region, if the throttling occurs in the shallow part of the wellbore, the temperature will drop too much, which enlarges the hydrate formation region, otherwise, if the throttling occurs in the deep part of the wellbore, the hydrate formation region will be reduced due to the decrease of the pressure.

  19. Microscopic structure and gas-gas critical line of the Ar-water system

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, M.A. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy)]. E-mail: riccim@fis.uniroma3.it; Mancinelli, R. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy); Lu Russo, M. [ESRF, European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble (France); Botti, A. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy); Bruni, F. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy); Soper, A.K. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

    2006-11-15

    The dependence of the derivative of the gas-gas critical temperature on the microscopic structure of a mixture is analyzed using neutron diffraction on the Ar-water system at two solute concentrations. At low Ar concentration the critical line departs from the critical point of the solvent with negative derivative: at a microscopic level this corresponds to a repulsive solute-solvent interaction, keeping Ar atoms outside the first water-water neighboring shell. As the solute concentration increases at constant temperature and pressure, the critical temperature goes through a minimum and eventually Ar atoms enter the first neighbor water shell. At this point, no H-bonding between water molecules is visible.

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

    Science.gov (United States)

    Maguire-Boyle, Samuel J; Barron, Andrew R

    2014-01-01

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

  1. Gas exchange under water : acclimation of terrestrial plants to submergence

    NARCIS (Netherlands)

    Mommer, Liesje

    2005-01-01

    Gas exchange between the plant and the environment is severely hampered when plants are submerged, leading to oxygen and energy deficits. A straightforward way to reduce these shortages of oxygen and carbohydrates would be prolonged photosynthesis under water, but this has received only little atten

  2. Electricity, Gas and Water Supply. Industry Training Monograph No. 4.

    Science.gov (United States)

    Dumbrell, Tom

    Australia's electricity, gas, and water supply industry employs only 0.8% of the nation's workers and employment in the industry has declined by nearly 39% in the last decade. This industry is substantially more dependent on the vocational education and training (VET) sector for skilled graduates than is the total Australian labor market. Despite…

  3. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  4. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  5. Methane gas seepage - Disregard of significant water column filter processes?

    Science.gov (United States)

    Schneider von Deimling, Jens; Schmale, Oliver

    2016-04-01

    Marine methane seepage represents a potential contributor for greenhouse gas in the atmosphere and is discussed as a driver for climate change. The ultimate question is how much methane is released from the seafloor on a global scale and what fraction may reach the atmosphere? Dissolved fluxes from methane seepage sites on the seabed were found to be very efficiently reduced by benthic microbial oxidation, whereas transport of free gas bubbles from the seabed is considered to bypass the effective benthic methane filter. Numerical models are available today to predict the fate of such methane gas bubble release to the water column in regard to gas exchange with the ambient water column, respective bubble lifetime and rise height. However, the fate of rising gas bubbles and dissolved methane in the water column is not only governed by dissolution, but is also affected by lateral oceanographic currents and vertical bubble-induced upwelling, microbial oxidation, and physico-chemical processes that remain poorly understood so far. According to this gap of knowledge we present data from two study sites - the anthropogenic North Sea 22/4b Blowout and the natural Coal Oil point seeps - to shed light into two new processes gathered with hydro-acoustic multibeam water column imaging and microbial investigations. The newly discovered processes are hereafter termed Spiral Vortex and Bubble Transport Mechanism. Spiral Vortex describes the evolution of a complex vortical fluid motion of a bubble plume in the wake of an intense gas release site (Blowout, North Sea). It appears very likely that it dramatically changes the dissolution kinetics of the seep gas bubbles. Bubble Transport Mechanism prescribes the transport of sediment-hosted bacteria into the water column via rising gas bubbles. Both processes act as filter mechanisms in regard to vertical transport of seep related methane, but have not been considered before. Spiral Vortex and Bubble Transport Mechanism represent the

  6. Experimental study on total dissolved gas supersaturation in water

    Directory of Open Access Journals (Sweden)

    Lu QU

    2011-12-01

    Full Text Available More and more high dams have been constructed and operated in China. The total dissolved gas (TDG supersaturation caused by dam discharge leads to gas bubble disease or even death of fish. Through a series of experiments, the conditions and requirements of supersaturated TDG generation were examined in this study. The results show that pressure (water depth, aeration, and bubble dissolution time are required for supersaturated TDG generation, and the air-water contact area and turbulence intensity are the main factors that affect the generation rate of supersaturated TDG. The TDG supersaturation levels can be reduced by discharging water to shallow shoals downstream of the dam or using negative pressure pipelines. Furthermore, the TDG supersaturation levels in stilling basins have no direct relationship with those in reservoirs. These results are of great importance for further research on the prediction of supersaturated TDG generation caused by dam discharge and aquatic protection.

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

    Institute of Scientific and Technical Information of China (English)

    黄颖怡; 王运东; 戴猷元

    2002-01-01

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

  8. Water Extraction from Coal-Fired Power Plant Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Bruce C. Folkedahl; Greg F. Weber; Michael E. Collings

    2006-06-30

    The overall objective of this program was to develop a liquid disiccant-based flue gas dehydration process technology to reduce water consumption in coal-fired power plants. The specific objective of the program was to generate sufficient subscale test data and conceptual commercial power plant evaluations to assess process feasibility and merits for commercialization. Currently, coal-fired power plants require access to water sources outside the power plant for several aspects of their operation in addition to steam cycle condensation and process cooling needs. At the present time, there is no practiced method of extracting the usually abundant water found in the power plant stack gas. This project demonstrated the feasibility and merits of a liquid desiccant-based process that can efficiently and economically remove water vapor from the flue gas of fossil fuel-fired power plants to be recycled for in-plant use or exported for clean water conservation. After an extensive literature review, a survey of the available physical and chemical property information on desiccants in conjunction with a weighting scheme developed for this application, three desiccants were selected and tested in a bench-scale system at the Energy and Environmental Research Center (EERC). System performance at the bench scale aided in determining which desiccant was best suited for further evaluation. The results of the bench-scale tests along with further review of the available property data for each of the desiccants resulted in the selection of calcium chloride as the desiccant for testing at the pilot-scale level. Two weeks of testing utilizing natural gas in Test Series I and coal in Test Series II for production of flue gas was conducted with the liquid desiccant dehumidification system (LDDS) designed and built for this study. In general, it was found that the LDDS operated well and could be placed in an automode in which the process would operate with no operator intervention or

  9. The Effect of Rain on Air-Water Gas Exchange

    Science.gov (United States)

    Ho, David T.; Bliven, Larry F.; Wanninkhof, Rik; Schlosser, Peter

    1997-01-01

    The relationship between gas transfer velocity and rain rate was investigated at NASA's Rain-Sea Interaction Facility (RSIF) using several SF, evasion experiments. During each experiment, a water tank below the rain simulator was supersaturated with SF6, a synthetic gas, and the gas transfer velocities were calculated from the measured decrease in SF6 concentration with time. The results from experiments with IS different rain rates (7 to 10 mm/h) and 1 of 2 drop sizes (2.8 or 4.2 mm diameter) confirm a significant and systematic enhancement of air-water gas exchange by rainfall. The gas transfer velocities derived from our experiment were related to the kinetic energy flux calculated from the rain rate and drop size. The relationship obtained for mono-dropsize rain at the RSIF was extrapolated to natural rain using the kinetic energy flux of natural rain calculated from the Marshall-Palmer raindrop size distribution. Results of laboratory experiments at RSIF were compared to field observations made during a tropical rainstorm in Miami, Florida and show good agreement between laboratory and field data.

  10. Reducing water usage with rotary regenerative gas/gas heat exchangers in natural gas-fired power plants with post-combustion carbon capture

    OpenAIRE

    Herraiz, Laura; Hogg, Dougal; Cooper, Jim; Gibbins, Jon; Lucquiaud, Mathieu

    2015-01-01

    It is possible to greatly mitigate the increase of water usage associated with the addition of carbon capture to fossil fuel power generation. This article presents a first-of-a-kind feasibility study of a series of technology options with rotary regenerative gas/gas heat exchangers for the management of the water balance around post-combustion carbon capture process integrated with Combined Cycle Gas Turbine (CCGT) plants with and without exhaust gas recirculation (EGR). Hybrid cooling confi...

  11. Case Studies of Water Shut-Off Treatments in Oil and Gas Production Wells

    National Research Council Canada - National Science Library

    Sławomir Falkowicz; Stanisław Dubiel; Renata Cicha-Szot

    2012-01-01

      Case Studies of Water Shut-Off Treatments in Oil and Gas Production Wells In this study some of the experimental results of water shut-off treatments in oil and gas production wells were presented...

  12. Determination of Vinyl Chloride at ug/l. Level in Water by Gas Chromatography

    Science.gov (United States)

    Bellar, Thomas A.; And Others

    1976-01-01

    A quantitative method for the determination of vinyl chloride in water is presented. Vinyl chloride is transfered to the gas phase by bubbling inert gas through the water. After concentration on silica gel or Carbosieve-B, determination is by gas chromatography. Confirmation of vinyl chloride is by gas chromatography-mass spectrometry. (Author/BT)

  13. 40 CFR 1065.645 - Amount of water in an ideal gas.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Amount of water in an ideal gas. 1065... in an ideal gas. This section describes how to determine the amount of water in an ideal gas, which... of water in an ideal gas, x H20, as follows: ER30AP10.034 Where: x H20 = amount of water in an ideal...

  14. The mechanism of the flowing ground water impacting on coalbed gas content

    Institute of Scientific and Technical Information of China (English)

    QIN Shengfei; SONG Yan; TANG Xiuyi; FU Guoyou

    2005-01-01

    The hydrogeological condition affects the coalbed gas storage dramatically. In an area of stronger hydrodynamics, the coal has a lower gas content, while a higher gas content exists in an area of weaker hydrodynamics. Obviously, the flowing groundwater is harmful to coalbed gas preservation. But few researches focus on the mechanism of how the flowing water diminishes the coalbed gas content.Based on the phenomenon that the flowing groundwater not only makes coalbed gas content lower, but also fractionates the carbon isotope, this research puts forward an idea that it is the water solution that diminishes the coalbed gas content,rather than the water-driven action or the gas dissipation through cap rocks. Only water-soluble action can both fractionate the carbon isotope and lessen the coalbed gas content,and it is an efficient way to take gas away and affect the gas content.

  15. Nuclear Magnetic Resonance Measurements of Original Water Saturation and Mobile Water Saturation in Low Permeability Sandstone Gas

    Institute of Scientific and Technical Information of China (English)

    GAO Shu-Sheng; YE Li-You; XIONG Wei; GUO He-Kun; HU Zhi-Ming

    2010-01-01

    @@ We use nuclear magnetic resonance(NMR)and centrifugation to measure the original water saturation and mobile water saturation of cores from the Xujiahe low permeability sandstone gas reservoir,and compare the NMR results with the corresponding field data.It is shown that the NMR water saturation after 300 psi centrifugation effectively represents the original water saturation measured by weighing fresh cores.There is a good correlation between mobile water saturation and the water production performance of the corresponding gas wells.The critical mobile water saturation whether reservoir produces water of the Xujiahe low permeability sandstone gas is 6%.The higher the mobile water saturation,the greater the water production rate of gas well.This indicates that well's water production performance can be forecasted by mobile water saturation of cores.

  16. Gasbuggy, New Mexico, Natural Gas and Produced Water Sampling and Analysis Results for 2011

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-09-01

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted natural gas sampling for the Gasbuggy, New Mexico, site on June 7 and 8, 2011. Natural gas sampling consists of collecting both gas samples and samples of produced water from gas production wells. Water samples from gas production wells were analyzed for gamma-emitting radionuclides, gross alpha, gross beta, and tritium. Natural gas samples were analyzed for tritium and carbon-14. ALS Laboratory Group in Fort Collins, Colorado, analyzed water samples. Isotech Laboratories in Champaign, Illinois, analyzed natural gas samples.

  17. Water management in capillary gas chromatographic air monitoring systems

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, A. [Perkin Elmer Corp., Norwalk, CT (United States). Fresh Aire Lab.

    1994-12-31

    Capillary gas chromatography is an excellent technique for the speciated quantitation of low-level volatile organic compounds (VOCs) in ambient air. Although GC detectors have excellent sensitivity, some sample pre-concentration will be necessary to enable detection of VOCs at sub-ppb levels. This process normally employs a cooled and/or adsorbent trap to retain the analytes from a large volume of sample air. For very volatile VOCs, a very retentive trap is used and this may also retain water present as vapor in the sample. This trapped water causes significant problems with the chromatography and detector operation and methods must be sought to remove it or eliminate its effects. This paper investigates the magnitude of the problem and examines the various alternatives for managing the trapped water. The application of some of these techniques is demonstrated in a method for the determination of volatile polar and non-polar toxic organic compounds in ambient air.

  18. Determination of Water Content of Water-soluble Paints by Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    顾润南; 钦维民; 肖舸

    2003-01-01

    This paper describes the determination of water content of water-soluble paints by gas chromatography. The water in paints is extracted by dimethyl formamide (DMF) as a solvent.Isopropanol is used as an internal standard. The mixture is separated by low-speed centrifugation.Then a 1-uL sample of the supernatant from the prepared solution is injected into the gas chromatograph. The water content is determined by internal standard calibration curve. The rate of recovery of added standard of this method is more than 98%. Relative mean deviation is less than 3‰.The linearity of calibration curve is good and relativity coefficient is higher than 0.998.

  19. Sterilization of Fungus in Water by Pulsed Power Gas Discharge Reactor Spraying Water Droplets for Water Treatment

    Science.gov (United States)

    Saito, Tsukasa; Handa, Taiki; Minamitani, Yasushi

    We study sterilization of bacteria in water using pulsed streamer discharge of gas phase. This method enhances efficiency of water treatment by spraying pretreatment water in a streamer discharge area. In this paper, yeast was sterilized because we assumed a case that fungus like mold existed in wastewater. As a result, colony forming units decreased rapidly for 2 minutes of the processing time, and all yeast sterilized by 45 minutes of the processing time.

  20. Kinetics of hydrate formation using gas bubble suspended in water

    Institute of Scientific and Technical Information of China (English)

    马昌峰; 陈光进; 郭天民

    2002-01-01

    An innovative experimental technique, which was devised to study the effects of temperature and pressure on the rate of hydrate formation at the surface of a gas bubble suspended in a stagnant water phase, was adapted in this work. Under such conditions, the hydrate-growth process is free from dynamic mass transfer factors. The rate of hydrate formation of methane and carbon dioxide has been systematically studied. The measured hydrate-growth data were correlated by using the molar Gibbs free energy as driving force. In the course of the experiments, some interesting surface phenomena were observed.

  1. Extinguishment of enclosed gas fires with water sprays

    Science.gov (United States)

    Wighus, R.

    1993-02-01

    Water sprays are widely used for fire fighting in industrial areas, and they are used for fire protection in the process industry and at offshore oil- and gas-production platforms. No real quantification of the effect of water sprays as a fire fighting medium exists. The water delivery is specified through standards and regulations which are based on industrial experience. In process areas, water spray is often used in deluge systems, intended to control the fire until the leakage of fuel has been shut down. For this purpose, there is a need for quantification of the ability a certain spray system has to remove heat from the fire and to reduce the fire load to the construction and process equipment. SINTEF NBL has studied extinguishment and control of enclosed hydrocarbon fires by means of water sprays. A scale model of a module of an offshore platform is used in studies of enclosed liquid hydrocarbon fire development. The model is instrumented to measure heat transfer, fire development, and production of soot and gases from combustion.

  2. Gasbuggy, New Mexico, Natural Gas and Produced Water Sampling Results for 2012

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-01

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual natural gas sampling for the Gasbuggy, New Mexico, Site on June 20 and 21, 2012. This long-term monitoring of natural gas includes samples of produced water from gas production wells that are located near the site. Water samples from gas production wells were analyzed for gamma-emitting radionuclides, gross alpha, gross beta, and tritium. Natural gas samples were analyzed for tritium and carbon-14. ALS Laboratory Group in Fort Collins, Colorado, analyzed water samples. Isotech Laboratories in Champaign, Illinois, analyzed natural gas samples.

  3. Wind driven vertical transport in a vegetated, wetland water column with air-water gas exchange

    Science.gov (United States)

    Poindexter, C.; Variano, E. A.

    2010-12-01

    Flow around arrays of cylinders at low and intermediate Reynolds numbers has been studied numerically, analytically and experimentally. Early results demonstrated that at flow around randomly oriented cylinders exhibits reduced turbulent length scales and reduced diffusivity when compared to similarly forced, unimpeded flows (Nepf 1999). While horizontal dispersion in flows through cylinder arrays has received considerable research attention, the case of vertical dispersion of reactive constituents has not. This case is relevant to the vertical transfer of dissolved gases in wetlands with emergent vegetation. We present results showing that the presence of vegetation can significantly enhance vertical transport, including gas transfer across the air-water interface. Specifically, we study a wind-sheared air-water interface in which randomly arrayed cylinders represent emergent vegetation. Wind is one of several processes that may govern physical dispersion of dissolved gases in wetlands. Wind represents the dominant force for gas transfer across the air-water interface in the ocean. Empirical relationships between wind and the gas transfer coefficient, k, have been used to estimate spatial variability of CO2 exchange across the worlds’ oceans. Because wetlands with emergent vegetation are different from oceans, different model of wind effects is needed. We investigated the vertical transport of dissolved oxygen in a scaled wetland model built inside a laboratory tank equipped with an open-ended wind tunnel. Plastic tubing immersed in water to a depth of approximately 40 cm represented emergent vegetation of cylindrical form such as hard-stem bulrush (Schoenoplectus acutus). After partially removing the oxygen from the tank water via reaction with sodium sulfite, we used an optical probe to measure dissolved oxygen at mid-depth as the tank water re-equilibrated with the air above. We used dissolved oxygen time-series for a range of mean wind speeds to estimate the

  4. EFFECT OF SURFACTANT ON TWO-PHASE FLOW PATTERNS OF WATER-GAS IN CAPILLARY TUBES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Flow patterns of liquid-gas two-phase flow were experimentally investigated. The experiments were carried out in both vertical and horizontal capillary tubes having inner diameters of 1.60 mm. The working liquid was the mixture of water and Sodium Dodecyl Benzoyl Sulfate (SDBS). The working gas was Nitrogen. For the water/SDBS mixture-gas flow in the vertical capillary tube, flow-pattern transitions occurred at lower flow velocities than those for the water-gas flow in the same tube. For the water/SDBS mixture-gas flow in the horizontal capillary tube, surface tension had little effect on the bubbly-intermittent transition and had only slight effect on the plug-slug and slug-annular transitions. However, surface tension had significant effect on the wavy stratified flow regime. The wavy stratified flow regime of water/SDBS mixture-gas flow expanded compared with that of water-gas.

  5. Simulation of Water Gas Shift Zeolite Membrane Reactor

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Rizki, Z.; Zunita, Megawati; Dharmawijaya, P. T.

    2017-07-01

    The search of alternative energy sources keeps growing from time to time. Various alternatives have been introduced to reduce the use of fossil fuel, including hydrogen. Many pathways can be used to produce hydrogen. Among all of those, the Water Gas Shift (WGS) reaction is the most common pathway to produce high purity hydrogen. The WGS technique faces a downstream processing challenge due to the removal hydrogen from the product stream itself since it contains a mixture of hydrogen, carbon dioxide and also the excess reactants. An integrated process using zeolite membrane reactor has been introduced to improve the performance of the process by selectively separate the hydrogen whilst boosting the conversion. Furthermore, the zeolite membrane reactor can be further improved via optimizing the process condition. This paper discusses the simulation of Zeolite Membrane Water Gas Shift Reactor (ZMWGSR) with variation of process condition to achieve an optimum performance. The simulation can be simulated into two consecutive mechanisms, the reaction prior to the permeation of gases through the zeolite membrane. This paper is focused on the optimization of the process parameters (e.g. temperature, initial concentration) and also membrane properties (e.g. pore size) to achieve an optimum product specification (concentration, purity).

  6. Essentials of water systems design in the oil, gas, and chemical processing industries

    CERN Document Server

    Bahadori, Alireza; Boyd, Bill

    2013-01-01

    Essentials of Water Systems Design in the Oil, Gas and Chemical Processing Industries provides valuable insight for decision makers by outlining key technical considerations and requirements of four critical systems in industrial processing plants—water treatment systems, raw water and plant water systems, cooling water distribution and return systems, and fire water distribution and storage facilities. The authors identify the key technical issues and minimum requirements related to the process design and selection of various water supply systems used in the oil, gas, and chemical processing industries. This book is an ideal, multidisciplinary work for mechanical engineers, environmental scientists, and oil and gas process engineers.

  7. Water-saving liquid-gas conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Christopher; Zhuang, Ye

    2014-01-14

    A method for treating a process gas with a liquid comprises contacting a process gas with a hygroscopic working fluid in order to remove a constituent from the process gas. A system for treating a process gas with a liquid comprises a hygroscopic working fluid comprising a component adapted to absorb or react with a constituent of a process gas, and a liquid-gas contactor for contacting the working fluid and the process gas, wherein the constituent is removed from the process gas within the liquid-gas contactor.

  8. Water-saving liquid-gas conditioning system

    Science.gov (United States)

    Martin, Christopher; Zhuang, Ye

    2014-01-14

    A method for treating a process gas with a liquid comprises contacting a process gas with a hygroscopic working fluid in order to remove a constituent from the process gas. A system for treating a process gas with a liquid comprises a hygroscopic working fluid comprising a component adapted to absorb or react with a constituent of a process gas, and a liquid-gas contactor for contacting the working fluid and the process gas, wherein the constituent is removed from the process gas within the liquid-gas contactor.

  9. Gas phase dispersion in compost as a function of different water contents and air flow rates

    Science.gov (United States)

    Sharma, Prabhakar; Poulsen, Tjalfe G.

    2009-07-01

    Gas phase dispersion in a natural porous medium (yard waste compost) was investigated as a function of gas flow velocity and compost volumetric water content using oxygen and nitrogen as tracer gases. The compost was chosen because it has a very wide water content range and because it represents a wide range of porous media, including soils and biofilter media. Column breakthrough curves for oxygen and nitrogen were measured at relatively low pore gas velocities, corresponding to those observed in for instance soil vapor extraction systems or biofilters for air cleaning at biogas plants or composting facilities. Total gas mechanical dispersion-molecular diffusion coefficients were fitted from the breakthrough curves using a one-dimensional numerical solution to the advection-dispersion equation and used to determine gas dispersivities at different volumetric gas contents. The results showed that gas mechanical dispersion dominated over molecular diffusion with mechanical dispersion for all water contents and pore gas velocities investigated. Importance of mechanical dispersion increased with increasing pore gas velocity and compost water content. The results further showed that gas dispersivity was relatively constant at high values of compost gas-filled porosity but increased with decreasing gas-filled porosity at lower values of gas-filled porosity. Results finally showed that measurement uncertainty in gas dispersivity is generally highest at low values of pore gas velocity.

  10. 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.

  11. 78 FR 64905 - Carriage of Conditionally Permitted Shale Gas Extraction Waste Water in Bulk

    Science.gov (United States)

    2013-10-30

    ... Waste Water in Bulk AGENCY: Coast Guard, DHS. ACTION: Notice of availability and request for comments... shale gas extraction waste water in bulk via barge, and invites public comment. The policy letter... endorsement or letter allowing the barge to transport shale gas extraction waste water in bulk. The...

  12. Greenhouse gas and energy co-benefits of water conservation[Water Sustainability Project

    Energy Technology Data Exchange (ETDEWEB)

    Maas, C.

    2009-03-15

    Energy is needed to deliver water to, within and from communities to remove contaminants from water and wastewater, and to heat water in homes. The interconnections between water and energy are referred to as the water-energy nexus. Large volumes of water are needed to generate energy, notably to power turbines, to cool thermal or nuclear energy plants, and to extract oil from tar sands. At the same time, large amounts of energy are needed to pump, treat, heat and distribute water for urban, industrial and agricultural use and to collect and treat the resulting wastewater. The two sides of the water-energy nexus are generating new research and policy proposals to address the challenges of climate change, energy security and increasing water scarcity. This report demonstrated that a large untapped opportunity exists for water conservation to reduce energy, municipal costs and greenhouse gas (GHG) emissions. The water-energy research in this study was based on a Soft Path for Water approach that incorporated facets of water demand management while moving beyond a short-term focus on cost-benefit criteria to examine how the services currently provided by water can be delivered to meet the need for economic, social and ecological sustainability. Although the research was conducted using data for municipalities in Ontario, the report is relevant to the rest of Canada and much of North America. Water conservation strategies included water efficiency measures such as high efficiency toilets and washing machines, as well as water saving measures such as xeriscaping and rainwater harvesting. The objectives of the study were to quantify the energy use associated with each component of the urban water use cycle and to determine the potential for energy and GHG emissions reductions associated with water conservation strategies. This report provided an overview of energy inputs needed for water provision. It outlined the methodology used to achieve the project objectives and

  13. Numerical Investigation of a Liquid-Gas Ejector Used for Shipping Ballast Water Treatment

    OpenAIRE

    Xueguan Song; Maosen Cao; Wonhyup Shin; Wenping Cao; Sanghoon Kang; Youngchul Park

    2014-01-01

    Shipping ballast water can have significant ecological and economic impacts on aquatic ecosystems. Currently, water ejectors are widely used in marine applications for ballast water treatment owing to their high suction capability and reliability. In this communication, an improved ballast treatment system employing a liquid-gas ejector is introduced to clear the ballast water to reduce environmental risks. Commonly, the liquid-gas ejector uses ballast water as the primary fluid and chemical ...

  14. High-Temperature Water-Gas Shift Membrane Reactor Study

    Energy Technology Data Exchange (ETDEWEB)

    Ciocco, M.V.; Iyoha, O.; Enick, R.M.; Killmeyer, R.P.

    2007-06-01

    NETL’s Office of Research and Development is exploring the integration of membrane reactors into coal gasification plants as a way of increasing efficiency and reducing costs. Water-Gas Shift Reaction experiments were conducted in membrane reactors at conditions similar to those encountered at the outlet of a coal gasifier. The changes in reactant conversion and product selectivity due to the removal of hydrogen via the membrane reactor were quantified. Research was conducted to determine the influence of residence time and H2S on CO conversion in both Pd and Pd80wt%Cu membrane reactors. Effects of the hydrogen sulfide-to-hydrogen ratio on palladium and a palladium-copper alloy at high-temperature were also investigated. These results were compared to thermodynamic calculations for the stability of palladium sulfides.

  15. The influence of the gas content of water and the flow velocity on cavitation erosion aggressiveness

    OpenAIRE

    Stoffel, Bernd; Širok, Brane; Dular, Matevž

    2015-01-01

    A study of the influence of the gas content of water and the flow velocity on cavitation erosion aggressiveness was performed. A cavitation tunnel with a single hydrofoil was used for the experiments. While the cavitation number andthe mean flow velocity remained constant throughout the tests, the gas content of the water was changed in steps from low (approximately 1%) to high (4 %). The gas content of the water was adjusted with a bubble generator. In addition tests at a constant cavitation...

  16. Pulsed electrical discharge in gas bubbles in water

    Science.gov (United States)

    Gershman, Sophia

    A phenomenological picture of pulsed electrical discharge in gas bubbles in water is produced by combining electrical, spectroscopic, and imaging methods. The discharge is generated by applying one microsecond long 5 to 20 kilovolt pulses between the needle and disk electrodes submerged in water. A gas bubble is generated at the tip of the needle electrode. The study includes detailed experimental investigation of the discharge in argon bubbles and a brief look at the discharge in oxygen bubbles. Imaging, electrical characteristics, and time-resolved optical emission data point to a fast streamer propagation mechanism and formation of a plasma channel in the bubble. Spectroscopic methods based on line intensity ratios and Boltzmann plots of line intensities of argon, atomic hydrogen, and argon ions and the examination of molecular emission bands from molecular nitrogen and hydroxyl radicals provide evidence of both fast beam-like electrons and slow thermalized ones with temperatures of 0.6 -- 0.8 electron-volts. The collisional nature of plasma at atmospheric pressure affects the decay rates of optical emission. Spectroscopic study of rotational-vibrational bands of hydroxyl radical and molecular nitrogen gives vibrational and rotational excitation temperatures of the discharge of about 0.9 and 0.1 electron-volt, respectively. Imaging and electrical evidence show that discharge charge is deposited on the bubble wall and water serves as a dielectric barrier for the field strength and time scales of this experiment. Comparing the electrical and imaging information for consecutive pulses applied at a frequency of 1 Hz indicates that each discharge proceeds as an entirely new process with no memory of the previous discharge aside from long-lived chemical species, such as ozone and oxygen. Intermediate values for the discharge gap and pulse duration, low repetition rate, and unidirectional character of the applied voltage pulses make the discharge process here unique

  17. Risks to Water Resources from Shale Gas Development and Hydraulic Fracturing in the United States

    Science.gov (United States)

    Vengosh, Avner; Jackson, Robert B.; Warner, Nathaniel; Darrah, Thomas H.; Kondash, Andrew

    2014-05-01

    The rise of shale gas development through horizontal drilling and high volume hydraulic fracturing has expanded oil and gas exploration in the USA. The rapid rate of shale gas exploration has triggered an intense public debate regarding the potential environmental and human health effects. A review of the updated literature has identified four potential risks for impacts on water resources: (1) stray gas contamination of shallow aquifers near shale gas sites; (2) contamination of surface water and shallow groundwater from spills, leaks, and disposal of inadequately treated wastewater or hydraulic fracturing fluids; (3) accumulation of toxic and radioactive residues in soil or stream sediments near disposal or spill sites; and (4) over-extraction of water resources for drilling and hydraulic fracturing that could induce water shortages and conflicts with other water users, particularly in water-scarce areas. As part of a long-term research on the potential water contamination associated with shale gas development, new geochemical and isotopic techniques have been developed for delineating the origin of gases and contaminants in water resource. In particular, multiple geochemical and isotopic (carbon isotopes in hydrocarbons, noble gas, strontium, boron, radium isotopes) tracers have been utilized to distinguish between naturally occurring dissolved gas and salts in water and contamination directly induced from shale gas drilling and hydraulic fracturing operations.

  18. A review of water and greenhouse gas impacts of unconventional natural gas development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Arent, Doug; Logan, Jeff; Macknick, Jordan; Boyd, William; Medlock , Kenneth; O' Sullivan, Francis; Edmonds, James A.; Clarke, Leon E.; Huntington, Hill; Heath, Garvin; Statwick, Patricia M.; Bazilian, Morgan

    2015-01-01

    This paper reviews recent developments in the production and use of unconventional natural gas in the United States with a focus on water and greenhouse gas emission implications. If unconventional natural gas in the U.S. is produced responsibly, transported and distributed with little leakage, and incorporated into integrated energy systems that are designed for future resiliency, it could play a significant role in realizing a more sustainable energy future; however, the increased use of natural gas as a substitute for more carbon intensive fuels will alone not substantially alter world carbon dioxide concentration projections.

  19. Simulating gas-water relative permeabilities for nanoscale porous media with interfacial effects

    Directory of Open Access Journals (Sweden)

    Wang Jiulong

    2017-08-01

    Full Text Available This paper presents a theoretical method to simulate gas-water relative permeability for nanoscale porous media utilizing fractal theory. The comparison between the calculation results and experimental data was performed to validate the present model. The result shows that the gas-water relative permeability would be underestimated significantly without interfacial effects. The thinner the liquid film thickness, the greater the liquid-phase relative permeability. In addition, both liquid surface diffusion and gas diffusion coefficient can promote gas-liquid two-phase flow. Increase of liquid surface diffusion prefer to increase liquid-phase permeability obviously as similar as increase of gas diffusion coefficient to increase gas-phase permeability. Moreover, the pore structure will become complicated with the increase of fractal dimension, which would reduce the gas-water relative permeability. This study has provided new insights for development of gas reservoirs with nanoscale pores such as shale.

  20. A COUPLING MODEL OF WATER FLOWS AND GAS FLOWS IN EXHAUSTED GAS BUBBLE ON MISSILE LAUNCHED UNDERWATER

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The gas and water flows during an underwater missile launch are numerically studied. For the gas flow, the explicit difference scheme of Non-oscillation and Non-free-parameter Dissipation (NND) is utilized to solve the Euler equations for compressible fluids in the body-fitted coordinates. For the water flow, the Hess-Smith method is employed to solve the Laplace equation for the velocity potential of irrotational water flows based on the potential theory and the boundary element method. The hybrid Eulerian-Lagrangian formulation for the free boundary conditions is used to compute the changes of the free surface of the exhausted gas bubble in time stepping. On the free surface of the exhausted gas bubble, the matched conditions of both the normal velocities and pressures are satisfied. From the numerical simulation, it is found that the exhausted gas bubble grows more rapidly in the axial direction than in the radial direction and the bubble will shrink at its "neck" finally. Numerical results of the movement of the shock wave and the distribution of the Mach number and the gas pressure within the bubble were presented, which reveals that at some time, the gas flow in the Laval nozzle is subsonic and the gas pressure in the nozzle is very high. Influences of various initial missile velocities and chamber total pressures and water depths on both the time interval when the gas flow in the nozzle is subsonic and the peak of the gas pressure at the nozzle end were discussed. It was suggested that a reasonable adjustment of the chamber total pressure can improve the performance of the engine during the underwater launch of missiles.

  1. Water Retention Curve and Relative Permeability for Gas Production from Hydrate-Bearing Sediments

    Science.gov (United States)

    Mahabadi, N.; Dai, S.; Seol, Y.; Jang, J.

    2014-12-01

    Water retention curve (soil water characteristic curve SWCC) and relative permeability equations are important to determine gas and water production for gas hydrate development. However, experimental studies to determine fitting parameters of those equations are not available in the literature. The objective of this research is to obtain reliable parameters for capillary pressure functions and relative permeability equations applicable to hydrate dissociation and gas production. In order to achieve this goal, (1) micro X-ray Computer Tomography (CT) is used to scan the specimen under 10MPa effective stress, (2) a pore network model is extracted from the CT image, (3) hydrate dissociation and gas expansion are simulated in the pore network model, (4) the parameters for the van Genuchten-type soil water characteristic curve and relative permeability equation during gas expansion are suggested. The research outcome will enhance the ability of numerical simulators to predict gas and water production rate.

  2. Paleo-oil-Water Contact and Present-Day Gas-Water Contact:Implication for Evolution History of Puguang Gas Field,Sichuan Basin,China

    Institute of Scientific and Technical Information of China (English)

    Li Pingping; Zou Huayao; Zhang Yuanchun; Wang Cunwu; Zhang Xuefeng

    2008-01-01

    The Puguang (普光) gas field is the largest gas field found in marine carbonate in China.The Puguang gas field experienced complicated evolution history from paleo-oil pool to gas pool.The purpose of this article is to reveal the evolution history of Puguang gas field through systematic study on the relationship between paleo-oil-water contact (POWC) and present-day gas-water contact (PGWC).POWC was recognized by observing the change of relative content of residual solid bitumen in the cores,and PGWC was observed using log and drilling stem test data.Two types of relationship between POWC and PGWC were observed in the Puguang gas field:POWC is above PGWC,and POWC is below PGWC.The former is normal as oil cracking may cause gas-water contact to move downward.The latter can be interpreted by lateral gas re-migration and re-accumulation caused by changes in structural configuration.The relationship between POWC and PGWC suggests that during oil charge,the southwestern and northwestern parts of the Puguang gas field were structurally lower than the northeastern and southeastern parts.Thrusting from Xuefengshan (雪峰山) since Yanshanian movement and from Dabashan (大巴山) since Himalayan movement resulted in the relative uplift of the southwestern and northwestern parts of the Puguang structure,which significantly changed the structural configuration.Based on the paleo-structure discussed in this article,the most probable migration directions of paleo-oil were from the northwest to the southeast and from the southwest to the northeast.Consequently,the evolution history of the Puguang gas field can be divided into three stages,namely,oil charging (200-170 Ma),cracking oil to gas (155-120 Ma),and gas pool adjustment (1200-0Ma).

  3. Impact of Shale Gas Development on Water Resource in Fuling, China

    Science.gov (United States)

    Yang, Hong; Huang, Xianjin; Yang, Qinyuan; Tu, Jianjun

    2015-04-01

    As a low-carbon energy, shale gas rapidly developed in U.S. in last years due to the innovation of the technique of hydraulic fracture, or fracking. Shale gas boom produces more gas with low price and reduced the reliance on fuel import. To follow the American shale gas success, China made an ambitious plan of shale gas extraction, 6.5 billion m3 by 2015. To extract shale gas, huge amount water is needed to inject into each gas well. This will intensify the competition of water use between industry, agricultural and domestic sectors. It may finally exacerbate the water scarcity in China. After the extraction, some water was returned to the ground. Without adequate treatment, the flowback water can introduce heavy metal, acids, pesticides, and other toxic material into water and land. This may inevitably worsen the water and land contamination. This study analysed the potential water consumption and wastewater generation in shale gas development in Fuling, Southwest China. The survey found the average water consumption is 30,000 cubic meter for one well, higher than shale well in U.S. Some 2%-20% water flowed back to the ground. The water quality monitoring showed the Total Suspended Solid (TSS) and Chemical Oxygen Demand (COD) were the main factors above those specified by China's water regulation. Shale gas is a lower-carbon energy, but it is important to recognize the water consuming and environmental pollution during the fracking. Strict monitoring and good coordination during the shale gas exploitation is urgently needed for the balance of economic development, energy demand and environmental protection.

  4. Water management technologies used by Marcellus Shale Gas Producers.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.; Environmental Science Division

    2010-07-30

    Natural gas represents an important energy source for the United States. According to the U.S. Department of Energy's (DOE's) Energy Information Administration (EIA), about 22% of the country's energy needs are provided by natural gas. Historically, natural gas was produced from conventional vertical wells drilled into porous hydrocarbon-containing formations. During the past decade, operators have increasingly looked to other unconventional sources of natural gas, such as coal bed methane, tight gas sands, and gas shales.

  5. Production behaviour of gas hydrate under hot sea water injection : laboratory case study

    Energy Technology Data Exchange (ETDEWEB)

    Nengkoda, A. [Schlumberger, Calgary, AB (Canada); Budhijanto, B.; Supranto, S.; Prasetyo, I.; Purwono, S.; Sutijan, S. [Gadjah Mada Univ., Yogyakarta (Indonesia)

    2010-07-01

    The gas hydrate potential in Indonesia was discussed, with particular reference to offshore production of gas from deep-water gas-hydrates by injection of hot seawater. In 2004, the Indonesian National Agency for Assessment and Application Technology estimated the gas hydrate resource potential to be 850 trillion cubic feet (tcf). To date, the 3 most reliable scenarios for gas hydrate production are thermal stimulation which involves increasing the temperature until the hydrates break into water and gas; depressurization which involves lowering the pressure by pumping out gas at the base of the hydrate to cause dissociation of hydrates into gas; and injection of a chemical inhibitor such as methanol into the hydrated sediments to cause destabilization, thus releasing gas from hydrates. This study investigated the effect of hot seawater injection on the gas hydrate production under laboratory conditions. The temperature profile distribution was examined along with operational parameters and flow characteristics of the dissociated gas and water from hydrates in porous systems under a synthetic hydrate setup. The study showed that gas production increases with time until a maximum is reached, at which time it begins to decrease. The energy ratio of thermal stimulation production was found to be influenced by the injection water temperature and rate as well as the hydrate content in the synthetic sediment. Scale problems were found to be associated with high temperature seawater injection. 8 refs., 3 tabs., 7 figs.

  6. Water use for Shale-gas production in Texas, U.S.

    Science.gov (United States)

    Nicot, Jean-Philippe; Scanlon, Bridget R

    2012-03-20

    Shale-gas production using hydraulic fracturing of mostly horizontal wells has led to considerable controversy over water-resource and environmental impacts. The study objective was to quantify net water use for shale-gas production using data from Texas, which is the dominant producer of shale gas in the U.S. with a focus on three major plays: the Barnett Shale (~15,000 wells, mid-2011), Texas-Haynesville Shale (390 wells), and Eagle Ford Shale (1040 wells). Past water use was estimated from well-completion data, and future water use was extrapolated from past water use constrained by shale-gas resources. Cumulative water use in the Barnett totaled 145 Mm(3) (2000-mid-2011). Annual water use represents ~9% of water use in Dallas (population 1.3 million). Water use in younger (2008-mid-2011) plays, although less (6.5 Mm(3) Texas-Haynesville, 18 Mm(3) Eagle Ford), is increasing rapidly. Water use for shale gas is water withdrawals; however, local impacts vary with water availability and competing demands. Projections of cumulative net water use during the next 50 years in all shale plays total ~4350 Mm(3), peaking at 145 Mm(3) in the mid-2020s and decreasing to 23 Mm(3) in 2060. Current freshwater use may shift to brackish water to reduce competition with other users.

  7. A conceptual review of water extraction requirements associated with shale gas activities in New Brunswick

    Energy Technology Data Exchange (ETDEWEB)

    O' Shea, K.J. [Dillon Consulting Limited (Canada)], email: koshea@dillon.ca

    2011-07-01

    With the depletion of conventional energy resources and the rising energy demand, the shale gas industry is growing. In North America, the percentage of this resource in the energy production mix is becoming significant, thanks to newly developed techniques which have created more economically viable opportunities. However, the public is expressing some concern over the water needs of the shale gas industry. The aim of this paper is to explain why the public is concerned with shale gas activity water usage and how the industry can address this concern. It is shown that shale gas developments are occurring in areas where no relationship exists between oil and gas industries and local communities and the public is therefore turning towards other, less scientifically rigorous, sources of information. This paper recommends that the industry benchmark its water usage against other activities so that the public can better understand the real impact of the shale gas industry on the water resources.

  8. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, E. Weitzel, C. Backman

    2017-06-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements.

  9. Simulation bidimensional of water and gas alternative injection; Simulacao bidimensional de injecao alternada de agua e gas

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Ana Paula Silva C. de

    1999-07-01

    This dissertation presents a study of the unidimensional of water and gas alternate injection (WAG) using the stream line theory. It is considered incompressible fluid., unit mobility ratio, negligible capillary and gravitational effects, homogeneous and isotropic reservoir, isothermal flow two phases, oil and water, and three components, oil, water and gas. In the stream line theory, the following injection schemes are considered: staggered line five-spot, direct line and seven-spot. It is also considered that there is no flow among the streams. In the WAG calculations it is used the fractional flow theory and the method of characteristics, which consists of shock waves and rarefactions. The composition of these waves is said compatible if it satisfies the entropy condition. The solution goes through a certain path from the left to the right side constrained by the initial and boundary conditions. The gas injection is at a high pressure to ensure miscible displacement. It is considered first injection of a water bank and then, injection of a gas bank. We concluded that the gas injection at a high pressure recoveries all residual oil and the water saturation remains is greater than initial saturation. (author)

  10. Selective removal of 226Ra2+ from gas-field-produced waters

    NARCIS (Netherlands)

    Leeuwen, van Fijs W.B.; Miermans, Cornelis J.H.; Beijleveld, Hans; Tomasberger, Tanja; Davis, Jeffery T.; Verboom, Willem; Reinhoudt, David N.

    2005-01-01

    The 226Ra2+ selectivity of both the self-assembled (iso)guanosine-based systems and ionizable thiacalix[4]crown dicarboxylic acids was determined in gas-field-produced water and a metal ion-containing model solution (simulant). Seven gas-field-produced water samples have been analyzed. From a sample

  11. Hydrate Formation/Dissociation in (Natural Gas + Water + Diesel Oil Emulsion Systems

    Directory of Open Access Journals (Sweden)

    Chang-Yu Sun

    2013-02-01

    Full Text Available Hydrate formation/dissociation of natural gas in (diesel oil + water emulsion systems containing 3 wt% anti-agglomerant were performed for five water cuts: 5, 10, 15, 20, and 25 vol%. The natural gas solubilities in the emulsion systems were also examined. The experimental results showed that the solubility of natural gas in emulsion systems increases almost linearly with the increase of pressure, and decreases with the increase of water cut. There exists an initial slow hydrate formation stage for systems with lower water cut, while rapid hydrate formation takes place and the process of the gas-liquid dissolution equilibrium at higher water cut does not appear in the pressure curve. The gas consumption amount due to hydrate formation at high water cut is significantly higher than that at low water cut. Fractional distillation for natural gas components also exists during the hydrate formation process. The experiments on hydrate dissociation showed that the dissociation rate and the amount of dissociated gas increase with the increase of water cut. The variations of temperature in the process of natural gas hydrate formation and dissociation in emulsion systems were also examined.

  12. Transport Membrane Condenser for Water and Energy Recovery from Power Plant Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Dexin Wang

    2012-03-31

    The new waste heat and water recovery technology based on a nanoporous ceramic membrane vapor separation mechanism has been developed for power plant flue gas application. The recovered water vapor and its latent heat from the flue gas can increase the power plant boiler efficiency and reduce water consumption. This report describes the development of the Transport Membrane Condenser (TMC) technology in details for power plant flue gas application. The two-stage TMC design can achieve maximum heat and water recovery based on practical power plant flue gas and cooling water stream conditions. And the report includes: Two-stage TMC water and heat recovery system design based on potential host power plant coal fired flue gas conditions; Membrane performance optimization process based on the flue gas conditions, heat sink conditions, and water and heat transport rate requirement; Pilot-Scale Unit design, fabrication and performance validation test results. Laboratory test results showed the TMC system can exact significant amount of vapor and heat from the flue gases. The recovered water has been tested and proved of good quality, and the impact of SO{sub 2} in the flue gas on the membrane has been evaluated. The TMC pilot-scale system has been field tested with a slip stream of flue gas in a power plant to prove its long term real world operation performance. A TMC scale-up design approach has been investigated and an economic analysis of applying the technology has been performed.

  13. Numerical simulation on submerged gas jet scouring pit morphology in impingement water bath dust removers

    Institute of Scientific and Technical Information of China (English)

    GAO Huijie; WU Xuan; ZHAO Yuxiang; WU Wenfei; LI Baowei

    2014-01-01

    The VOF interface tracking method was adopted to simulate the two-dimensional submerged gas jet scouring pit morphology in an impingement water bath dust remover.The interaction of gas/liquid two-phase was obtained by force balance and momentum exchange.On the self-designed impingement water bath dust remover test bench,the submerged gas jet flushing with different gas velocities was simulated. The results show that,the gas inlet velocity is one of the main factors affecting the submerged gas jet scou-ring pit characteristics.The unique nature of gas/liquid two-phase determines their unique way of move-ment,thus affects the morphological character of the scouring pit in the expansion lag phase.Within the study range,the characteristic radius and impact depth of the scouring pit increases with the gas velocity, and so are their growth rates.

  14. Low sulfur content hot reducing gas production using calcium oxide desulfurization with water recycle

    Energy Technology Data Exchange (ETDEWEB)

    Feinman, J.; Mcgreal, J.E.

    1982-03-23

    A process and apparatus are claimed for producing a low sulfur content, hot reducing gas by desulfurizing hot reducing gas. This is done in the following manner; by contacting the sulfur-bearing hot reducing gas with a bed of a particulate calcium oxide desulfurizing agent to thereby produce a product gas stream and a byproduct calcium sulfide compositions recovering sulfur from the calcium sulfide composition by contacting the calcium sulfide composition with hot liquid water at a temperature and corresponding pressure sufficient to maintain steam in the system and to thereby convert the sulfide to calcium hydroxide and hydrogen sulfide and to produce a liquid water stream containing sulfur; combining the sulfur containing water stream with a fresh water stream and recycling this water stream for contacting the calcium sulfide composition. Preferably water vapor produced in the contacting step is condensed and returned to the system in the final stage of contacting the calcium sulfide composition with hot liquid water.

  15. Flared natural gas-based onsite atmospheric water harvesting (AWH) for oilfield operations

    Science.gov (United States)

    Wikramanayake, Enakshi D.; Bahadur, Vaibhav

    2016-03-01

    Natural gas worth tens of billions of dollars is flared annually, which leads to resource waste and environmental issues. This work introduces and analyzes a novel concept for flared gas utilization, wherein the gas that would have been flared is instead used to condense atmospheric moisture. Natural gas, which is currently being flared, can alternatively power refrigeration systems to generate the cooling capacity for large scale atmospheric water harvesting (AWH). This approach solves two pressing issues faced by the oil-gas industry, namely gas flaring, and sourcing water for oilfield operations like hydraulic fracturing, drilling and water flooding. Multiple technical pathways to harvest atmospheric moisture by using the energy of natural gas are analyzed. A modeling framework is developed to quantify the dependence of water harvest rates on flared gas volumes and ambient weather. Flaring patterns in the Eagle Ford Shale in Texas and the Bakken Shale in North Dakota are analyzed to quantify the benefits of AWH. Overall, the gas currently flared annually in Texas and North Dakota can harvest enough water to meet 11% and 65% of the water consumption in the Eagle Ford and the Bakken, respectively. Daily harvests of upto 30 000 and 18 000 gallons water can be achieved using the gas currently flared per well in Texas and North Dakota, respectively. In fifty Bakken sites, the water required for fracturing or drilling a new well can be met via onsite flared gas-based AWH in only 3 weeks, and 3 days, respectively. The benefits of this concept are quantified for the Eagle Ford and Bakken Shales. Assessments of the global potential of this concept are presented using data from countries with high flaring activity. It is seen that this waste-to-value conversion concept offers significant economic benefits while addressing critical environmental issues pertaining to oil-gas production.

  16. Simulation of gas production from hydrate reservoir by the combination of warm water flooding and depressurization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Gas production from hydrate reservoir by the combination of warm water flooding and depressurization is proposed,which can overcome the deficiency of single production method.Based on the combination production method,the physical and mathematical models are developed to simulate the hydrate dissociation.The mathematical model can be used to analyze the effects of the flow of multiphase fluid,the kinetic process of hydrate dissociation,the endothermic process of hydrate dissociation,ice-water phase equilibrium,the convection and conduction on the hydrate dissociation and gas and water production.The mechanism of gas production by the combination of warm water flooding and depressurization is revealed by the numerical simulation.The evolutions of such physical variables as pressure,temperature,saturations and gas and water rates are analyzed.Numerical results show that under certain conditions the combination method has the advantage of longer stable period of high gas rate than the single producing method.

  17. Hazard-Specific Vulnerability Mapping for Water Security in a Shale Gas Context

    Science.gov (United States)

    Allen, D. M.; Holding, S.; McKoen, Z.

    2015-12-01

    Northeast British Columbia (NEBC) is estimated to hold large reserves of unconventional natural gas and has experienced rapid growth in shale gas development activities over recent decades. Shale gas development has the potential to impact the quality and quantity of surface and ground water. Robust policies and sound water management are required to protect water security in relation to the water-energy nexus surrounding shale gas development. In this study, hazard-specific vulnerability mapping was conducted across NEBC to identify areas most vulnerable to water quality and quantity deterioration due to shale gas development. Vulnerability represents the combination of a specific hazard threat and the susceptibility of the water system to that threat. Hazard threats (i.e. potential contamination sources and water abstraction) were mapped spatially across the region. The shallow aquifer susceptibility to contamination was characterised using the DRASTIC aquifer vulnerability approach, while the aquifer susceptibility to abstraction was mapped according to aquifer productivity. Surface water susceptibility to contamination was characterised on a watershed basis to describe the propensity for overland flow (i.e. contaminant transport), while watershed discharge estimates were used to assess surface water susceptibility to water abstractions. The spatial distribution of hazard threats and susceptibility were combined to form hazard-specific vulnerability maps for groundwater quality, groundwater quantity, surface water quality and surface water quantity. The vulnerability maps identify priority areas for further research, monitoring and policy development. Priority areas regarding water quality occur where hazard threat (contamination potential) coincide with high aquifer susceptibility or high overland flow potential. Priority areas regarding water quantity occur where demand is estimated to represent a significant proportion of estimated supply. The identification

  18. Effect of water injection on nitric oxide emissions of a gas turbine combustor burning natural gas fuel

    Science.gov (United States)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    The effect of direct water injection on the exhaust gas emissions of a turbojet combustor burning natural gas fuel was investigated. The results are compared with the results from similar tests using ASTM Jet-A fuel. Increasing water injection decreased the emissions of oxides of nitrogen (NOX) and increased the emissions of carbon monoxide and unburned hydrocarbons. The greatest percentage decrease in NOX with increasing water injection was at the lowest inlet-air temperature tested. The effect of increasing inlet-air temperature was to decrease the effect of the water injection. The reduction in NOX due to water injection was almost identical to the results obtained with Jet-A fuel. However, the emission indices of unburned hydrocarbons, carbon monoxide, and percentage nitric oxide in NOX were not.

  19. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-19

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  20. Thermal injuries caused by ignition of volatile substances by gas water heaters.

    Science.gov (United States)

    Rutan, R L; Desai, M H; Herndon, D N

    1993-01-01

    Based on the cumulative data of this tertiary care facility over the past 25 years, one out of every 70 pediatric patients admitted to our institution sustained their injuries during an explosive event instigated by the ignition of volatile substances from gas water heaters. The majority of injuries related to gas water heaters can be prevented by decreasing the temperature setpoint of the heater, by protecting the heater element itself, and by elevating the water heater to 18 inches above the floor. The first two issues have been adequately addressed; however, gas-fueled water heaters continue to be installed at floor level. Current national guidelines are too rigid and do not adequately address water-heater installation in private residences. Although general prevention campaigns target appropriate storage of volatile substances, they rarely address the explosive potential of gas water heaters in combination with combustible fumes.

  1. Charming water-wave with natural gas technology. Hints for planning natural-gas use in hairdressers' shops

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzfischer, I.

    Both fitters of natural-gas equipment and advisers on the staff of gas utilities who deal with hairdressers' shops must have detailed knowledge of the ins and outs of the business to be able to make a correct assessment of heating and hot-water requirements before deciding on the capacity and type of devices. Rates also play an important part in that trade. The paper presents detailed information on water-heating in hairdressers' shops. Advisory staff will find important clues.

  2. A water column study of methane around gas flares located at the West Spitsbergen continental margin

    DEFF Research Database (Denmark)

    Gentz, Torben; Damm, Ellen; von Deimling, Jens Schneider

    2014-01-01

    L1. Our results suggest that the methane dissolved from gas bubbles is efficiently trapped below the pycnocline and thus limits the methane concentration in surface water and the air–sea exchange during summer stratification. During winter the lateral stratification breaks down and fractions...... the fate of the released gas due to dissolution of methane from gas bubbles and subsequent mixing, transport and microbial oxidation. The oceanographic data indicated a salinity-controlled pycnocline situated ∼20 m above the seafloor. A high resolution sampling program at the pycnocline at the active gas...... in the δ13CCH4 values point to a 13C depleted methane source (∼ –60‰ VPDB) being mainly mixed with a background values of the ambient water (∼–37.5‰ VPDB). A gas bubble dissolution model indicates that ∼80% of the methane released from gas bubbles into the ambient water takes place below the pycnocline...

  3. An optimization framework for the integration of water management and shale gas supply chain design

    OpenAIRE

    Guerra, O. J.; Calderon, A. J.; Papageorgiou, L. G.; Siirola, J. J.; Reklaitis, G. V.

    2016-01-01

    This study presents the mathematical formulation and implementation of a comprehensive optimization framework for the assessment of shale gas resources. The framework simultaneously integrates water management and the design and planning of the shale gas supply chain, from the shale formation to final product demand centers and from fresh water supply for hydraulic fracturing to water injection and/or disposal. The framework also addresses some issues regarding wastewater quality, i.e., total...

  4. Spatiotemporal Variability in Hydraulic Fracturing Water Use and Water Produced with Shale Gas in the U.S.

    Science.gov (United States)

    Nicot, J. P.; Scanlon, B. R.; Reedy, R. C.

    2016-12-01

    Longer time series and increasing data availability allows more comprehensive assessment of spatiotemporal variability in hydraulic fracturing (HF) water use and flowback/produced (FP) water generation in shale plays in the U.S. In this analysis we quantified HF and FP water volumes for seven major shale gas plays in the U.S. using detailed well by well analyses through 2015. Well count ranges from 1,500 (Utica) to 20,200 (Barnett) with total cumulative? HF water use ranging from 12 billion gallons (bgal) (Utica) to 65 bgal (Barnett). HF water use/well has been increasing over time in many plays and currently ranges from 4.5 mgal/well (Fayetteville) to 10 mgal/well (Utica) (2015). Normalizing by lateral length results in a range of 900 gal/ft (Fayetteville) to 15,600 gal/ft (Marcellus) (2015). FP water volumes are also highly variable, lowest in the Utica and highest in the Barnett. Management of FP water is mostly through disposal into Class II salt water injection wells, with the exception of the Marcellus where >90% of the FP water is reused/recycled. Along the dramatic domestic gas production increase, electricity generation from natural gas has almost doubled since 2000. It is important to consider the water use for HF in terms of the lifecycle of natural gas with HF water consumption. It is equivalent to <10% of the water consumed in natural gas-fired power plants that usually require less water than coal-fired power plants, resulting in net water savings.

  5. Saskatchewan water policy : what does the oil and gas industry need to know

    Energy Technology Data Exchange (ETDEWEB)

    Dybvig, W. [Saskatchewan Watershed Authority, Regina, SK (Canada)

    2004-07-01

    Water use and supply in the province of Saskatchewan was discussed along with planning activities, regulatory processes and current water issues facing the province. The Saskatchewan Watershed Authority was created to address water use and concerns regarding water protection. Some historical information regarding water management strategies in the province of Saskatchewan was presented, including the creation of SaskWater in 1984; the provincial wetlands policy in 1995; a water management framework in 1999; the North Battleford water contamination in 2001; a long term drinking water strategy in 2002; and the creation of the Saskatchewan Watershed Authority in 2002. The Saskatchewan Watershed Authority took over responsibilities from SaskWater, the Saskatchewan Wetlands Conservation Corporation and Saskatchewan Environment with a mandate for watershed planning; water source protection; wetlands conservation; water allocation; infrastructure management; and public education about water. This presentation explained how the Saskatchewan Watershed Authority will achieve its goals for a safe and sustainable water supply, and healthy watersheds and aquifers. Industrial water use charges were described with reference to the oil and gas industry in Saskatchewan, the second largest crude oil producer in Canada and the third largest natural gas producer. In 2002 there 1700 gas well and 3400 oil wells drilled in the province. All non domestic water uses require approval from the Saskatchewan Watershed Authority. Regulations for groundwater use and purchasing water from other users were also outlined. tabs., figs.

  6. Simultaneous stack-gas scrubbing and waste water treatment

    Science.gov (United States)

    Poradek, J. C.; Collins, D. D.

    1980-01-01

    Simultaneous treatment of wastewater and S02-laden stack gas make both treatments more efficient and economical. According to results of preliminary tests, solution generated by stack gas scrubbing cycle reduces bacterial content of wastewater. Both processess benefit by sharing concentrations of iron.

  7. Simultaneous stack-gas scrubbing and waste water treatment

    Science.gov (United States)

    Poradek, J. C.; Collins, D. D.

    1980-01-01

    Simultaneous treatment of wastewater and S02-laden stack gas make both treatments more efficient and economical. According to results of preliminary tests, solution generated by stack gas scrubbing cycle reduces bacterial content of wastewater. Both processess benefit by sharing concentrations of iron.

  8. Gas-Liquid Precipitation of Water Dissolved Heavy Metal Ions Using Hydrogen Sulfide Gas

    OpenAIRE

    Al-Tarazi, Mousa

    2004-01-01

    Precipitation of solids promoted by gas-liquid reactions is applied in many industrial processes such as the production of ammonium phosphate, ammonium sulphate, barium carbonate, calcium carbonate, calcium fluoride, ypsum (calcium sulphate), goethite, sodium bicarbonate, strontium carbonate and terephthalic acid. In ddition gas-liquid precipitation can be applied in gas cleaning, heavy metal removal and in biotechnology. Despite the importance of this subject no extensive studies have yet be...

  9. Direct simulation of liquid water dynamics in the gas channel of a polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Rensink, D.; Hassanizadeh, S.M.; Fell, S.

    2012-01-01

    For better water management in gas channels (GCs) of polymer electrolyte fuel cells (PEFCs), a profound understanding of the liquid water dynamics is needed. In this study, we propose a novel geometrical setup to conduct a series of direct simulations of the liquid water dynamics in a GC. The conduc

  10. Gas Well Top Hole Locations, LP and LNG - Marcellus Gas Well Water Sources View

    Data.gov (United States)

    NSGIC Education | GIS Inventory — This data set contains all approved water sources within water managment plans (WMP). A WMP contains water sources utilized in the fracture stimulation of Marcellus...

  11. An evaluation of water quality in private drinking water wells near natural gas extraction sites in the Barnett Shale formation.

    Science.gov (United States)

    Fontenot, Brian E; Hunt, Laura R; Hildenbrand, Zacariah L; Carlton, Doug D; Oka, Hyppolite; Walton, Jayme L; Hopkins, Dan; Osorio, Alexandra; Bjorndal, Bryan; Hu, Qinhong H; Schug, Kevin A

    2013-09-03

    Natural gas has become a leading source of alternative energy with the advent of techniques to economically extract gas reserves from deep shale formations. Here, we present an assessment of private well water quality in aquifers overlying the Barnett Shale formation of North Texas. We evaluated samples from 100 private drinking water wells using analytical chemistry techniques. Analyses revealed that arsenic, selenium, strontium and total dissolved solids (TDS) exceeded the Environmental Protection Agency's Drinking Water Maximum Contaminant Limit (MCL) in some samples from private water wells located within 3 km of active natural gas wells. Lower levels of arsenic, selenium, strontium, and barium were detected at reference sites outside the Barnett Shale region as well as sites within the Barnett Shale region located more than 3 km from active natural gas wells. Methanol and ethanol were also detected in 29% of samples. Samples exceeding MCL levels were randomly distributed within areas of active natural gas extraction, and the spatial patterns in our data suggest that elevated constituent levels could be due to a variety of factors including mobilization of natural constituents, hydrogeochemical changes from lowering of the water table, or industrial accidents such as faulty gas well casings.

  12. Zeolite Membrane Reactor for Water Gas Shift Reaction for Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jerry Y.S. [Arizona State Univ., Mesa, AZ (United States)

    2013-01-29

    Gasification of biomass or heavy feedstock to produce hydrogen fuel gas using current technology is costly and energy-intensive. The technology includes water gas shift reaction in two or more reactor stages with inter-cooling to maximize conversion for a given catalyst volume. This project is focused on developing a membrane reactor for efficient conversion of water gas shift reaction to produce a hydrogen stream as a fuel and a carbon dioxide stream suitable for sequestration. The project was focused on synthesizing stable, hydrogen perm-selective MFI zeolite membranes for high temperature hydrogen separation; fabricating tubular MFI zeolite membrane reactor and stable water gas shift catalyst for membrane reactor applications, and identifying experimental conditions for water gas shift reaction in the zeolite membrane reactor that will produce a high purity hydrogen stream. The project has improved understanding of zeolite membrane synthesis, high temperature gas diffusion and separation mechanisms for zeolite membranes, synthesis and properties of sulfur resistant catalysts, fabrication and structure optimization of membrane supports, and fundamentals of coupling reaction with separation in zeolite membrane reactor for water gas shift reaction. Through the fundamental study, the research teams have developed MFI zeolite membranes with good perm-selectivity for hydrogen over carbon dioxide, carbon monoxide and water vapor, and high stability for operation in syngas mixture containing 500 part per million hydrogen sulfide at high temperatures around 500°C. The research teams also developed a sulfur resistant catalyst for water gas shift reaction. Modeling and experimental studies on the zeolite membrane reactor for water gas shift reaction have demonstrated the effective use of the zeolite membrane reactor for production of high purity hydrogen stream.

  13. Development of Novel Water-Gas Shift Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ho, W. S. Winston

    2004-12-29

    This report summarizes the objectives, technical barrier, approach, and accomplishments for the development of a novel water-gas-shift (WGS) membrane reactor for hydrogen enhancement and CO reduction. We have synthesized novel CO{sub 2}-selective membranes with high CO{sub 2} permeabilities and high CO{sub 2}/H{sub 2} and CO{sub 2}/CO selectivities by incorporating amino groups in polymer networks. We have also developed a one-dimensional non-isothermal model for the countercurrent WGS membrane reactor. The modeling results have shown that H{sub 2} enhancement (>99.6% H{sub 2} for the steam reforming of methane and >54% H{sub 2} for the autothermal reforming of gasoline with air on a dry basis) via CO{sub 2} removal and CO reduction to 10 ppm or lower are achievable for synthesis gases. With this model, we have elucidated the effects of system parameters, including CO{sub 2}/H{sub 2} selectivity, CO{sub 2} permeability, sweep/feed flow rate ratio, feed temperature, sweep temperature, feed pressure, catalyst activity, and feed CO concentration, on the membrane reactor performance. Based on the modeling study using the membrane data obtained, we showed the feasibility of achieving H{sub 2} enhancement via CO{sub 2} removal, CO reduction to {le} 10 ppm, and high H{sub 2} recovery. Using the membrane synthesized, we have obtained <10 ppm CO in the H{sub 2} product in WGS membrane reactor experiments. From the experiments, we verified the model developed. In addition, we removed CO{sub 2} from a syngas containing 17% CO{sub 2} to about 30 ppm. The CO{sub 2} removal data agreed well with the model developed. The syngas with about 0.1% CO{sub 2} and 1% CO was processed to convert the carbon oxides to methane via methanation to obtain <5 ppm CO in the H{sub 2} product.

  14. Quantitative calculation of GOR of complex oil-gas-water systems with logging data: A case study of the Yingdong Oil/Gas Field in the Qaidam Basin

    OpenAIRE

    2014-01-01

    In the Yingdong Oil/Gas Field of the Qaidam Basin, multiple suites of oil-gas-water systems overlie each other vertically, making it difficult to accurately identify oil layers from gas layers and calculate gas-oil ratio (GOR). Therefore, formation testing and production data, together with conventional logging, NMR and mud logging data were integrated to quantitatively calculate GOR. To tell oil layers from gas layers, conventional logging makes use of the excavation effect of compensated ne...

  15. Influence of Gas Components on the Formation of Carbonyl Sulfide over Water-Gas Shift Catalyst B303Q

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Water-gas shift reaction catalyst at lower temperature (200-400 ℃) may improve the conversion of carbon monoxide. But carbonyl sulfide was found to be present over the sulfided cobaltmolybdenum/alumina catalyst for water-gas shift reaction. The influences of temperature, space velocity,and gas components on the formation of carbonyl sulfide over sulfided cobalt-molybdenum/alumina catalyst B303Q at 200-400 ℃ were studied in a tubular fixed-bed quartz-glass reactor under simulated water-gas shift conditions. The experimental results showed that the yield of carbonyl sulfide over B303Q catalyst reached a maximum at 220 ℃ with the increase in temperature, sharply decreased with the increase in space velocity and the content of water vapor, increased with the increase in the content of carbon monoxide and carbon dioxide, and its yield increased and then reached a stable value with the increase in the content of hydrogen and hydrogen sulfide. The formation mechanism of carbonyl sulfide over B303Q catalyst at 200-400 ℃ was discussed on the basis of how these factors influence the formation of COS. The yield of carbonyl sulfide over B303Q catalyst at 200-400 ℃ was the combined result of two reactions, that is, COS was first produced by the reaction of carbon monoxide with hydrogen sulfide,and then the as-produced COS was converted to hydrogen sulfide and carbon dioxide by hydrolysis. The mechanism of COS formation is assumed as follows: sulfur atoms in the Co9Ss-MoS2/Al2O3 crystal lattice were easily removed and formed carbonyl sulfide with CO, and then hydrogen sulfide in the water-gas shift gas reacted with the crystal lattice oxygen atoms in CoO-MoO3/Al2O3 to form Co9Ss-MoS2/Al2O3.This mechanism for the formation of COS over water-gas shift catalyst B303Q is in accordance with the Mars-Van Krevelen's redox mechanism over metal sulfide.

  16. Building America Top Innovations 2012: Tankless Gas Water Heater Performance

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-01-01

    This Building America Top Innovations profile describes Building America field testing that shed light on how real-world water usage affects energy saving estimates of high-efficiency water heating systems.

  17. An overview of oil-water separation using gas flotation systems.

    Science.gov (United States)

    Saththasivam, Jayaprakash; Loganathan, Kavithaa; Sarp, Sarper

    2016-02-01

    Oil concentration levels in municipal waste water effluent streams are stringently regulated in most parts of the world. Apart from municipal waste, stricter oil/grease discharge limits are also enforced in oil and gas sectors as large volumes of produced water is being discharged to open ocean. One of the feasible, practical and established methods to remove oil substances from waste water sources is by gas flotation. In this overview, gas flotation technologies, namely dissolved and induced flotation systems, are discussed. Physico-chemical interaction between oil-water-gas during flotation is also summarized. In addition to a brief review on design advancements in flotation systems, enhancement of flotation efficiency by using pre-treatment methods, particularly coagulation-flocculation, is also presented.

  18. Unplugging and Profile Adjusting Technology By Using Gas in Water Injectors

    Institute of Scientific and Technical Information of China (English)

    Liu Guangyuan

    1994-01-01

    @@ A new technique of unplugging and profile controlling by gas in water-injectors has been developed by Mr. Sun Hongyu, the lecturer of Chemical Department of Jilin Oilfield Technical Training School, and his colleagues.

  19. Air-water Gas Exchange Rates on a Large Impounded River Measured Using Floating Domes (Poster)

    Science.gov (United States)

    Mass balance models of dissolved gases in rivers typically serve as the basis for whole-system estimates of greenhouse gas emission rates. An important component of these models is the exchange of dissolved gases between air and water. Controls on gas exchange rates (K) have be...

  20. Simulation of Water Level Fluctuations in a Hydraulic System Using a Coupled Liquid-Gas Model

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2015-08-01

    Full Text Available A model for simulating vertical water level fluctuations with coupled liquid and gas phases is presented. The Preissmann implicit scheme is used to linearize the governing equations for one-dimensional transient flow for both liquid and gas phases, and the linear system is solved using the chasing method. Some classical cases for single liquid and gas phase transients in pipelines and networks are studied to verify that the proposed methods are accurate and reliable. The implicit scheme is extended using a dynamic mesh to simulate the water level fluctuations in a U-tube and an open surge tank without consideration of the gas phase. Methods of coupling liquid and gas phases are presented and used for studying the transient process and interaction between the phases, for gas phase limited in a chamber and gas phase transported in a pipeline. In particular, two other simplified models, one neglecting the effect of the gas phase on the liquid phase and the other one coupling the liquid and gas phases asynchronously, are proposed. The numerical results indicate that the asynchronous model performs better, and are finally applied to a hydropower station with surge tanks and air shafts to simulate the water level fluctuations and air speed.

  1. Flow structure of conical distributed multiple gas jets injected into a water chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jiajun; Yu, Yonggang [Nanjing University of Science and Technology, Nanjing (China)

    2017-04-15

    Based on an underwater gun firing project, a mock bullet with several holes on the head was designed and experimented to observe the combustion gas injected into a cylindrical water chamber through this mock bullet. The combustion gas jets contain one vertical central jet and 4 to 8 slant lateral jets. A high speed camera system was used to record the expansion of gas jets in the experimental study. In numerical simulations, the Euler two-fluid model and volume of fluid method were adopted to describe the gas-liquid flow. The results show the backflow zone in lateral jet is the main factor influencing the gas-liquid turbulent mixing in downstream. On cross sections, the gas volume fraction increased with time but the growth rate decreased. With a change of nozzle structure, the gas fraction was more affected than the shock structure.

  2. The water retention curve and relative permeability for gas production from hydrate-bearing sediments: pore-network model simulation

    Science.gov (United States)

    Mahabadi, Nariman; Dai, Sheng; Seol, Yongkoo; Sup Yun, Tae; Jang, Jaewon

    2016-08-01

    The water retention curve and relative permeability are critical to predict gas and water production from hydrate-bearing sediments. However, values for key parameters that characterize gas and water flows during hydrate dissociation have not been identified due to experimental challenges. This study utilizes the combined techniques of micro-focus X-ray computed tomography (CT) and pore-network model simulation to identify proper values for those key parameters, such as gas entry pressure, residual water saturation, and curve fitting values. Hydrates with various saturation and morphology are realized in the pore-network that was extracted from micron-resolution CT images of sediments recovered from the hydrate deposit at the Mallik site, and then the processes of gas invasion, hydrate dissociation, gas expansion, and gas and water permeability are simulated. Results show that greater hydrate saturation in sediments lead to higher gas entry pressure, higher residual water saturation, and steeper water retention curve. An increase in hydrate saturation decreases gas permeability but has marginal effects on water permeability in sediments with uniformly distributed hydrate. Hydrate morphology has more significant impacts than hydrate saturation on relative permeability. Sediments with heterogeneously distributed hydrate tend to result in lower residual water saturation and higher gas and water permeability. In this sense, the Brooks-Corey model that uses two fitting parameters individually for gas and water permeability properly capture the effect of hydrate saturation and morphology on gas and water flows in hydrate-bearing sediments.

  3. Experimental study of flow patterns and pressure drops of heavy oil-water-gas vertical flow

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-mao; ZHONG Hai-quan; LI Ying-chuan; LIU Zhong-neng; WANG Qi

    2014-01-01

    A stainless steel apparatus of 18.5 m high and 0.05 m in inner diameter is developed, with the heavy oil from Lukeqin Xinjiang oil field as the test medium, to carry out the orthogonal experiments for the interactions between heavy oil-water and heavy oil-water-gas. With the aid of observation windows, the pressure drop signal can be collected and the general multiple flow patterns of heavy oil-water-gas can be observed, including the bubble, slug, churn and annular ones. Compared with the conventional oil, the bubble flows are identified in three specific flow patterns which are the dispersed bubble (DB), the bubble gas-bubble heavy oil go(B-B), and the bubble gas-intermittent heavy oilgo(B-I). The slug flows are identified in two specific flow patterns which are the intermittent gas-bubble heavy oilgo(I-B)and the intermittent gas-intermittent heavy oilgo(I-I). Compared with the observa- tions in the heavy oil-water experiment, it is found that the conventional models can not accurately predict the pressure gradient. And it is not water but heavy oil and water mixed phase that is in contact with the tube wall. So, based on the principle of the energy con- servation and the kinematic wave theory, a new method is proposed to calculate the frictional pressure gradient. Furthermore, with the new friction gradient calculation method and a due consideration of the flow characteristics of the heavy oil-water-gas high speed flow, a new model is built to predict the heavy oil-water-gas pressure gradient. The predictions are compared with the experiment data and the field data. The accuracy of the predictions shows the rationality and the applicability of the new model.

  4. Water Vapor Interference Correction in a Non Dispersive Infrared Multi-Gas Analyzer

    Institute of Scientific and Technical Information of China (English)

    SUN You-Wen; LIU Wen-Qing; ZENG Yi; WANG Shi-Mei; HUANG Shu-Hua; XIE Pin-Hua; YU Xiao-Man

    2011-01-01

    We demonstrate an effective method to eliminate the interfering effect of water vapor in a non-dispersive infrared multi-gas analyzer.The response coefficients of water vapor at each filter channel are measured from the humidity of the ambient air.Based on the proposed method,the water vapor interference is corrected with the measured response coefficients.By deducting the absorbance of each filter channel related to water vapor,the measuring precision of the analyzer is improved significantly and the concentration retrieval correlation accuracy of each target gas is more than 99%.

  5. Gas content of some thermal and thermal-mineral waters in Bosnia and Herzogovinia

    Energy Technology Data Exchange (ETDEWEB)

    Derkovic, B. (Geoinzenjering, Sarajevo, Yugoslavia)

    Studies were made of the gas content of thermal waters from nine wells in Bosnia and Herzogovinia. The wells are located at Kulasi, Olovo, Laktasi, Fojnica, Slatina, Gornji, Ilidza near Sarajevo, and Ilidza near Banja Luka. All the waters were characterized by nitrogen and originate at fairly shallow depths. The gas contents of the waters, in terms of C, CO/sub 2/, O/sub 2/, N/sub 2/, H/sub 2/S, He, Ne, As, Kr, and Xe are reported. Due to their ease of recovery, these waters are extensively used in balneological applications.

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

    Science.gov (United States)

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

    2016-04-20

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

  7. Gas-Liquid Precipitation of water dissolved heavy metal ions using hydrogen sulfide gas

    NARCIS (Netherlands)

    Al Tarazi, M.Y.M.

    2004-01-01

    Precipitation of solids promoted by gas-liquid reactions is applied in many industrial processes such as the production of ammonium phosphate, ammonium sulphate, barium carbonate, calcium carbonate, calcium fluoride, ypsum (calcium sulphate), goethite, sodium bicarbonate, strontium carbonate and

  8. Gas-Liquid Precipitation of Water Dissolved Heavy Metal Ions Using Hydrogen Sulfide Gas

    NARCIS (Netherlands)

    Al-Tarazi, Mousa

    2004-01-01

    Precipitation of solids promoted by gas-liquid reactions is applied in many industrial processes such as the production of ammonium phosphate, ammonium sulphate, barium carbonate, calcium carbonate, calcium fluoride, ypsum (calcium sulphate), goethite, sodium bicarbonate, strontium carbonate and te

  9. Economics of residential gas furnaces and water heaters in US new construction market

    OpenAIRE

    Lekov, Alex B.; Franco, Victor H.; Wong-Parodi, Gabrielle; McMahon, James E.; CHAN, Peter

    2010-01-01

    New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

  10. Economics of residential gas furnaces and water heaters in United States new construction market

    OpenAIRE

    Lekov, Alex B.

    2010-01-01

    New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

  11. The Effect of Water Spray upon Incineration Flue Gas Clean—up

    Institute of Scientific and Technical Information of China (English)

    HaigangWang; BinLi; 等

    2000-01-01

    The existence of liquid water was found very important in incineration flue gas clean-up systems for enhancing the absorption of acid components contained.In a newly developed incineration flue gas clean-up tower,which works in a semi-dry mode,the water is injected in the form of spray to maximum its contact surface with the gas.The criteria for the design of the water nozzles would be high water concentration but no liquid impinging on the solid wall and complete evaporation inside the tower,In order to optimize the atomizer design,the effects of the spray type (hollow or solid cone),their initial droplet size distribution and water flow rate on the performance of the acid gas absorption were investigated.The liquid behaviour was studied with a fluid dynamic simulation code,and the overall performance was checked experimentally.This paper presents the use of a commercial CFD code,FLUENT,and some modifications made during such investigation.The modification includes the viscosity of the flue gas defined as a function of the temperature,and the initial mass fraction of different droplet size group described with an exponential distribution formula of Rosin-Rammler.The investigation results (the optimal spray parameters)were used to guide the water nozzle design.The general performance of the flue gas clean-up system measured during the plant operation complied with the design criteria.

  12. Reclamation of potable water from mixed gas streams

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, Roddie R.; Bischoff, Brian L.; Debusk, Melanie Moses; Narula, Chaitanya

    2016-07-19

    An apparatus for separating a liquid from a mixed gas stream can include a wall, a mixed gas stream passageway, and a liquid collection assembly. The wall can include a first surface, a second surface, and a plurality of capillary condensation pores. The capillary condensation pores extend through the wall, and have a first opening on the first surface of the wall, and a second opening on the second surface of the wall. The pore size of the pores can be between about 2 nm to about 100 nm. The mixed gas stream passageway can be in fluid communication with the first opening. The liquid collection assembly can collect liquid from the plurality of pores.

  13. Gas production and transport during bench-scale electrical resistance heating of water and trichloroethene.

    Science.gov (United States)

    Hegele, P R; Mumford, K G

    2014-09-01

    The effective remediation of chlorinated solvent source zones using in situ thermal treatment requires successful capture of gas that is produced. Replicate electrical resistance heating experiments were performed in a thin bench-scale apparatus, where water was boiled and pooled dense non-aqueous phase liquid (DNAPL) trichloroethene (TCE) and water were co-boiled in unconsolidated silica sand. Quantitative light transmission visualization was used to assess gas production and transport mechanisms. In the water boiling experiments, nucleation, growth and coalescence of the gas phase into connected channels were observed at critical gas saturations of Sgc=0.233±0.017, which allowed for continuous gas transport out of the sand. In experiments containing a colder region above a target heated zone, condensation prevented the formation of steam channels and discrete gas clusters that mobilized into colder regions were trapped soon after discontinuous transport began. In the TCE-water experiments, co-boiling at immiscible fluid interfaces resulted in discontinuous gas transport above the DNAPL pool. Redistribution of DNAPL was also observed above the pool and at the edge of the vapor front that propagated upwards through colder regions. These results suggest that the subsurface should be heated to water boiling temperatures to facilitate gas transport from specific locations of DNAPL to extraction points and reduce the potential for DNAPL redistribution. Decreases in electric current were observed at the onset of gas phase production, which suggests that coupled electrical current and temperature measurements may provide a reliable metric to assess gas phase development.

  14. Nonlinear analysis of gas-water/oil-water two-phase flow in complex networks

    CERN Document Server

    Gao, Zhong-Ke; Wang, Wen-Xu

    2014-01-01

    Understanding the dynamics of multi-phase flows has been a challenge in the fields of nonlinear dynamics and fluid mechanics. This chapter reviews our work on two-phase flow dynamics in combination with complex network theory. We systematically carried out gas-water/oil-water two-phase flow experiments for measuring the time series of flow signals which is studied in terms of the mapping from time series to complex networks. Three network mapping methods were proposed for the analysis and identification of flow patterns, i.e. Flow Pattern Complex Network (FPCN), Fluid Dynamic Complex Network (FDCN) and Fluid Structure Complex Network (FSCN). Through detecting the community structure of FPCN based on K-means clustering, distinct flow patterns can be successfully distinguished and identified. A number of FDCN’s under different flow conditions were constructed in order to reveal the dynamical characteristics of two-phase flows. The FDCNs exhibit universal power-law degree distributions. The power-law exponent ...

  15. July 2010 Natural Gas and Produced Water Sampling at the Gasbuggy, New Mexico, Site

    Energy Technology Data Exchange (ETDEWEB)

    Plessinger, Mark [S.M. Stoller Corporation, Broomfield, CO (United States)

    2011-01-01

    Annual natural gas and produced water monitoring was conducted for gas wells adjacent to Section 36, where the Gasbuggy test was conducted, in accordance with the draft Long-Term Surveillance and Maintenance Plan for the Gasbuggy Site, Rio Arriba County, New Mexico. Sampling and analysis was conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites. (LMS/PLN/S04351, continually updated). Natural gas samples were collected for tritium and carbon-14 analysis. Produced water samples were collected and analyzed for tritium, gamma-emitting radionuclides (by high-resolution gamma spectrometry), gross alpha, and gross beta. An additional water sample was collected from well 29-6 Water Hole for analysis of tritium and gamma-emitting radionuclides. A duplicate produced water sample was collected from well 30-039-21743.

  16. Local area water removal analysis of a proton exchange membrane fuel cell under gas purge conditions.

    Science.gov (United States)

    Lee, Chi-Yuan; Lee, Yu-Ming; Lee, Shuo-Jen

    2012-01-01

    In this study, local area water content distribution under various gas purging conditions are experimentally analyzed for the first time. The local high frequency resistance (HFR) is measured using novel micro sensors. The results reveal that the liquid water removal rate in a membrane electrode assembly (MEA) is non-uniform. In the under-the-channel area, the removal of liquid water is governed by both convective and diffusive flux of the through-plane drying. Thus, almost all of the liquid water is removed within 30 s of purging with gas. However, liquid water that is stored in the under-the-rib area is not easy to remove during 1 min of gas purging. Therefore, the re-hydration of the membrane by internal diffusive flux is faster than that in the under-the-channel area. Consequently, local fuel starvation and membrane degradation can degrade the performance of a fuel cell that is started from cold.

  17. June 2011 Natural Gas and Produced Water Sampling at the Gasbuggy, New Mexico, Site

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-10-01

    Annual natural gas and produced water monitoring was conducted for gas wells adjacent to Section 36, where the Gasbuggy test was conducted, in accordance with the draft Long-Term Surveillance and Maintenance Plan for the Gasbuggy Site, Rio Arriba County, New Mexico. Sampling and analysis were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PLN/S04351, continually updated). Natural gas samples were collected for tritium and carbon-14 analyses. Produced water samples were collected and analyzed for tritium, gamma-emitting radionuclides (by high-resolution gamma spectrometry), gross alpha, and gross beta. A duplicate produced water sample was collected from well 30-039-21743. Produced water samples were not collected at locations 30-039-30161 and 30-039-21744 because of the lack of water. Samples were not collected from location 30-039-29988 because the well was shut-in.

  18. Effect of liquid distribution on gas-water phase mass transfer in an unsaturated sand during infiltration

    Science.gov (United States)

    Imhoff, Paul T.; Jaffé, Peter R.

    1994-09-01

    Gas-water phase mass transfer was examined in a homogeneous sand with both the gas and water phase mobile: water was infiltrated from the top of the sand column while benzene-laden air flowed upward from the bottom. Mass-transfer limitations for this situation may be important for applications of bioventing, where water and nutrients are added at the ground surface simultaneously with induced air movement to carry oxygen and volatile organics to microbial populations. Gas- and water-phase samples indicate that gas-water phase mass transfer was sufficiently fast that equilibrium between gas and water phases was achieved at all sampling locations within the porous medium. Lower-bound estimates for the gas-water mass-transfer rate coefficient show that mass transfer was at least 10-40 times larger than predictions made from an empirical model developed for gas-water phase mass transfer in an identical porous medium. A water-phase tracer test demonstrates that water flow was much more uniform in this study than in those earlier experiments, which is a likely explanation for the differing rates of gas-water phase mass transfer. It is hypothesized that the liquid distribution in previous laboratory experiments was less uniform because of preferential flow paths due to wetting front instabilities. Gas-water phase mass-transfer rate coefficients reported in this investigation are for an ideal situation of uniform water infiltration: mass-transfer rates in field soils are expected to be significantly smaller.

  19. Desalination and reuse of high-salinity shale gas produced water: drivers, technologies, and future directions.

    Science.gov (United States)

    Shaffer, Devin L; Arias Chavez, Laura H; Ben-Sasson, Moshe; Romero-Vargas Castrillón, Santiago; Yip, Ngai Yin; Elimelech, Menachem

    2013-09-03

    In the rapidly developing shale gas industry, managing produced water is a major challenge for maintaining the profitability of shale gas extraction while protecting public health and the environment. We review the current state of practice for produced water management across the United States and discuss the interrelated regulatory, infrastructure, and economic drivers for produced water reuse. Within this framework, we examine the Marcellus shale play, a region in the eastern United States where produced water is currently reused without desalination. In the Marcellus region, and in other shale plays worldwide with similar constraints, contraction of current reuse opportunities within the shale gas industry and growing restrictions on produced water disposal will provide strong incentives for produced water desalination for reuse outside the industry. The most challenging scenarios for the selection of desalination for reuse over other management strategies will be those involving high-salinity produced water, which must be desalinated with thermal separation processes. We explore desalination technologies for treatment of high-salinity shale gas produced water, and we critically review mechanical vapor compression (MVC), membrane distillation (MD), and forward osmosis (FO) as the technologies best suited for desalination of high-salinity produced water for reuse outside the shale gas industry. The advantages and challenges of applying MVC, MD, and FO technologies to produced water desalination are discussed, and directions for future research and development are identified. We find that desalination for reuse of produced water is technically feasible and can be economically relevant. However, because produced water management is primarily an economic decision, expanding desalination for reuse is dependent on process and material improvements to reduce capital and operating costs.

  20. Developing Water Resource Security in a Greenhouse Gas Constrained Context - A Case Study in California

    Science.gov (United States)

    Tarroja, B.; Aghakouchak, A.; Samuelsen, S.

    2015-12-01

    The onset of drought conditions in regions such as California due to shortfalls in precipitation has brought refreshed attention to the vulnerability of our water supply paradigm to changes in climate patterns. In the face of a changing climate which can exacerbate drought conditions in already dry areas, building resiliency into our water supply infrastructure requires some decoupling of water supply availability from climate behavior through conservation, efficiency, and alternative water supply measures such as desalination and water reuse. The installation of these measures requires varying degrees of direct energy inputs and/or impacts the energy usage of the water supply infrastructure (conveyance, treatment, distribution, wastewater treatment). These impacts have implications for greenhouse gas emissions from direct fuel usage or impacts on the emissions from the electric grid. At the scale that these measures may need to be deployed to secure water supply availability, especially under climate change impacted hydrology, they can potentially pose obstacles for meeting greenhouse gas emissions reduction and renewable utilization goals. Therefore, the portfolio of these measures must be such that detrimental impacts on greenhouse gas emissions are minimized. This study combines climate data with a water reservoir network model and an electric grid dispatch model for the water-energy system of California to evaluate 1) the different pathways and scale of alternative water resource measures needed to secure water supply availability and 2) the impacts of following these pathways on the ability to meet greenhouse gas and renewable utilization goals. It was discovered that depending on the water supply measure portfolio implemented, impacts on greenhouse gas emissions and renewable utilization can either be beneficial or detrimental, and optimizing the portfolio is more important under climate change conditions due to the scale of measures required.

  1. Environmental turbulent mixing controls on air-water gas exchange in marine and aquatic systems

    Science.gov (United States)

    Zappa, Christopher J.; McGillis, Wade R.; Raymond, Peter A.; Edson, James B.; Hintsa, Eric J.; Zemmelink, Hendrik J.; Dacey, John W. H.; Ho, David T.

    2007-05-01

    Air-water gas transfer influences CO2 and other climatically important trace gas fluxes on regional and global scales, yet the magnitude of the transfer is not well known. Widely used models of gas exchange rates are based on empirical relationships linked to wind speed, even though physical processes other than wind are known to play important roles. Here the first field investigations are described supporting a new mechanistic model based on surface water turbulence that predicts gas exchange for a range of aquatic and marine processes. Findings indicate that the gas transfer rate varies linearly with the turbulent dissipation rate to the ${^1}\\!/{_4 power in a range of systems with different types of forcing - in the coastal ocean, in a macro-tidal river estuary, in a large tidal freshwater river, and in a model (i.e., artificial) ocean. These results have important implications for understanding carbon cycling.

  2. Effect of biochar on soil structural characteristics: water retention and gas transport

    DEFF Research Database (Denmark)

    Sun, Zhencai; Møldrup, Per; Vendelboe, Anders Lindblad

    Biochar addition to agricultural soil has been reported to reduce climate gas emission, as well as improve soil fertility and crop productivity. Little, however, is known about biochar effects on soil structural characteristics. This study investigates if biochar-application changes soil structural...... characteristics, as indicated from water retention and gas transport measurements on intact soil samples. Soil was sampled from a field experiment on a sandy loam with four control plots (C) without biochar and four plots (B) with incorporated biochar at a rate of 20 tons per hectare (plot size, 6 x 8 m). The C......-gas diffusivity on intact 100cm3 soil samples (5 replicates in each plot). We found that biochar application significantly decreased soil bulk density, hereby creating higher porosity. At the same soil-water matric potential, all the soil-gas phase parameters (air-filled porosity, air permeability and gas...

  3. The Water-Induced Linear Reduction Gas Diffusivity Model Extended to Three Pore Regions

    DEFF Research Database (Denmark)

    Chamindu, T. K. K. Deepagoda; de Jonge, Lis Wollesen; Kawamoto, Ken

    2015-01-01

    . Characterization of soil functional pore structure is an essential prerequisite to understand key gas transport processes in variably saturated soils in relation to soil ecosystems, climate, and environmental services. In this study, the water-induced linear reduction (WLR) soil gas diffusivity model originally......An existing gas diffusivity model developed originally for sieved, repacked soils was extended to characterize gas diffusion in differently structured soils and functional pore networks. A gas diffusivity-derived pore connectivity index was used as a measure of soil structure development...... developed for sieved, repacked soil was extended to two simple, linear regions to characterize gas diffusion and functional pore-network structure also in intact, structured soil systems. Based on the measurements in soils with markedly different pore regions, we showed that the two linear regions can...

  4. Tomographic Imaging of Water Injection and Withdrawal in PEMFC Gas Diffusion Layers

    Energy Technology Data Exchange (ETDEWEB)

    McGill U; Gostick, J. T.; Gunterman, H. P.; Weber, A. Z.; Newman, J. S.; Kienitz, B. L.; MacDowell, A. A.

    2010-06-25

    X-ray computed tomography was used to visualize the water configurations inside gas diffusion layers for various applied capillary pressures, corresponding to both water invasion and withdrawal. A specialized sample holder was developed to allow capillary pressure control on the small-scale samples required. Tests were performed on GDL specimens with and without hydrophobic treatments.

  5. Notes on the path and wake of a gas bubble rising in pure water

    NARCIS (Netherlands)

    de Vries, A.W.G.; Biesheuvel, A.; van Wijngaarden, L.; van Wijngaarden, L.

    2002-01-01

    This paper is concerned with the structure of the wake behind gas bubbles rising at high Reynolds numbers in highly purified water. It describes a schlieren optics technique to visualise the wake. The technique does not contaminate the water, and so does not affect the zero-stress condition at the

  6. Challenges of Membrane Filtration for Produced Water Treatment in Offshore Oil & Gas Production

    DEFF Research Database (Denmark)

    Jepsen, Kasper Lund; Hansen, Leif; Mai, Christian

    2016-01-01

    Tremendous amount of produced water are discharged into the sea from offshore oil & gas installations. Along with every barrel of oil three barrels of water are produced and this is only worsen as the fields mature. Enhanced oil recovery (EOR) is employed to increase production, as a part of EOR...

  7. Comparison of oil removal in surfactant alternating gas with water alternating gas, water flooding and gas flooding in secondary oil recovery process

    OpenAIRE

    Salehi, Mehdi Mohammad; Safarzadeh, Mohammad Amin; Sahraei, Eghbal; Nejad, Seyyed Alireza Tabatabaei

    2014-01-01

    Growing oil prices coupled with large amounts of residual oil after operating common enhanced oil recovery methods has made using methods with higher operational cost economically feasible. Nitrogen is one of the gases used in both miscible and immiscible gas injection process in oil reservoir. In heterogeneous formations gas tends to breakthrough early in production wells due to overriding, fingering and channeling. Surfactant alternating gas (SAG) injection is one of the methods commonly us...

  8. Identification, Verification, and Compilation of Produced Water Management Practices for Conventional Oil and Gas Production Operations

    Energy Technology Data Exchange (ETDEWEB)

    Rachel Henderson

    2007-09-30

    The project is titled 'Identification, Verification, and Compilation of Produced Water Management Practices for Conventional Oil and Gas Production Operations'. The Interstate Oil and Gas Compact Commission (IOGCC), headquartered in Oklahoma City, Oklahoma, is the principal investigator and the IOGCC has partnered with ALL Consulting, Inc., headquartered in Tulsa, Oklahoma, in this project. State agencies that also have partnered in the project are the Wyoming Oil and Gas Conservation Commission, the Montana Board of Oil and Gas Conservation, the Kansas Oil and Gas Conservation Division, the Oklahoma Oil and Gas Conservation Division and the Alaska Oil and Gas Conservation Commission. The objective is to characterize produced water quality and management practices for the handling, treating, and disposing of produced water from conventional oil and gas operations throughout the industry nationwide. Water produced from these operations varies greatly in quality and quantity and is often the single largest barrier to the economic viability of wells. The lack of data, coupled with renewed emphasis on domestic oil and gas development, has prompted many experts to speculate that the number of wells drilled over the next 20 years will approach 3 million, or near the number of current wells. This level of exploration and development undoubtedly will draw the attention of environmental communities, focusing their concerns on produced water management based on perceived potential impacts to fresh water resources. Therefore, it is imperative that produced water management practices be performed in a manner that best minimizes environmental impacts. This is being accomplished by compiling current best management practices for produced water from conventional oil and gas operations and to develop an analysis tool based on a geographic information system (GIS) to assist in the understanding of watershed-issued permits. That would allow management costs to be kept in

  9. Characterization factors for water consumption and greenhouse gas emissions based on freshwater fish species extinction.

    Science.gov (United States)

    Hanafiah, Marlia M; Xenopoulos, Marguerite A; Pfister, Stephan; Leuven, Rob S E W; Huijbregts, Mark A J

    2011-06-15

    Human-induced changes in water consumption and global warming are likely to reduce the species richness of freshwater ecosystems. So far, these impacts have not been addressed in the context of life cycle assessment (LCA). Here, we derived characterization factors for water consumption and global warming based on freshwater fish species loss. Calculation of characterization factors for potential freshwater fish losses from water consumption were estimated using a generic species-river discharge curve for 214 global river basins. We also derived characterization factors for potential freshwater fish species losses per unit of greenhouse gas emission. Based on five global climate scenarios, characterization factors for 63 greenhouse gas emissions were calculated. Depending on the river considered, characterization factors for water consumption can differ up to 3 orders of magnitude. Characterization factors for greenhouse gas emissions can vary up to 5 orders of magnitude, depending on the atmospheric residence time and radiative forcing efficiency of greenhouse gas emissions. An emission of 1 ton of CO₂ is expected to cause the same impact on potential fish species disappearance as the water consumption of 10-1000 m³, depending on the river basin considered. Our results make it possible to compare the impact of water consumption with greenhouse gas emissions.

  10. Operation, Modeling and Analysis of the Reverse Water Gas Shift Process

    Science.gov (United States)

    Whitlow, Jonathan E.

    2001-01-01

    The Reverse Water Gas Shift process is a candidate technology for water and oxygen production on Mars under the In-Situ Propellant Production project. This report focuses on the operation and analysis of the Reverse Water Gas Shift (RWGS) process, which has been constructed at Kennedy Space Center. A summary of results from the initial operation of the RWGS, process along with an analysis of these results is included in this report. In addition an evaluation of a material balance model developed from the work performed previously under the summer program is included along with recommendations for further experimental work.

  11. Application of various water soluble polymers in gas hydrate inhibition

    DEFF Research Database (Denmark)

    Kamal, Muhammad Shahzad; Hussein, Ibnelwaleed A.; Sultan, Abdullah S.

    2016-01-01

    . This review presents the various types of water soluble polymers used for hydrate inhibition, including conventional and novel polymeric inhibitors along with their limitations. The review covers the relevant properties of vinyl lactam, amide, dendrimeric, fluorinated, and natural biodegradable polymers...

  12. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface ground water: background, base cases, shallow reservoirs, short-term gas and water transport

    Science.gov (United States)

    Researchers examined gas and water transport between a deep tight shale gas reservoir and a shallow overlying aquifer in the two years following hydraulic fracturing, assuming a pre-existing connecting pathway.

  13. Data and prediction of water content of high pressure nitrogen, methane and natural gas

    DEFF Research Database (Denmark)

    Folas, Georgios; Froyna, E.W.; Lovland, J.;

    2007-01-01

    New data for the equilibrium water content of nitrogen, methane and one natural gas mixture are presented. The new binary data and existing binary sets were compared to calculated values of dew point temperature using both the CPA (Cubic-Plus-Association) EoS and the GERG-water EoS. CPA is purely...... predictive (i.e. all binary interaction parameters are set equal to 0), while GERG-water uses a temperature dependent interaction parameter fitted to published data. The GERG-water model is proposed as an ISO standard for determining the water content of natural gas. The data sets for nitrogen cover...... they have large scatter. The data sets that have been measured at low pressures extrapolate well towards the ideal equilibrium values. The two models show similar results, but differ at high pressure and/or temperature. CPA is shown to extrapolate well for methane-water to 1000 bar and 573 K, and our...

  14. An investigation of Water-gas interface migration of the upper Paleozoic gas pool of the Ordos Basin using reservoir fluid inclusion information

    Institute of Scientific and Technical Information of China (English)

    MI Jingkui; XIAO Xianming; LIU Dehan; LI Xianqing; SHEN Jiagui

    2004-01-01

    There is a particular characteristic in the for-mation of the Upper Paleozoic gas pool in the Ordos Basin that is its water-gas interface migrated regional during geological history.However,there has been lack of detailed research on this paper,the formation time of hte fluid inclusions formed in the water-gas transition zone of the gas pool was deduced using their trapping temperatures and combining of the burial with geothermal history of the basin.On the basis of this,the isochrone of water-gas interface migration for the gas pool was mapped .The result shows that the gas pool began to form around the yanan Area at about 165Ma,and then developed and enlarged toward the north direction.The gas pool finally formed at about 129 Ma.Since the basin uplifted from the late Cretaceous and gas supply decreased,the water-gas interface of the gas pool migratec back to the present position.

  15. Direct measurement of the capillary pressure characteristics of water-air-gas diffusion layer systems for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gostick, Jeff T.; Ioannidis, Marios A.; Fowler, Michael W.; Pritzker, Mark D. [Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON (Canada)

    2008-10-15

    A method and apparatus for measuring the relationship between air-water capillary pressure and water saturation in PEMFC gas diffusion layers (GDL) is described. Capillary pressure data for water injection and withdrawal from typical GDL materials are obtained, which demonstrate permanent hysteresis between water intrusion and water withdrawal. Capillary pressure, defined as the difference between the water and gas pressures at equilibrium, is positive during water injection and negative during water withdrawal. The results contribute to the understanding of liquid water behavior in GDL materials which is necessary for the development of effective PEMFC water management strategies. (author)

  16. Life Cycle Water Consumption and Wastewater Generation Impacts of a Marcellus Shale Gas Well

    OpenAIRE

    Jiang, Mohan; Hendrickson, Chris T.; VanBriesen, Jeanne M.

    2013-01-01

    This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the econ...

  17. Performance assessment of water mist applied in gas burning sup-pression in underground coal mine

    Institute of Scientific and Technical Information of China (English)

    YU Ming-gao; ZHENG Li-gang; LIU Zhi-chao; PAN Rong-kun; JIA Hai-lin; YUAN Jun

    2006-01-01

    The main objective of the present study was introduced water mist suppression technologyto prevent and control gas burning which occurred during drilling at Wu20160 working-face in No.10 coal mine of Pingdingshan Ltd.. Based on the self-developed experiment platform, a series of fire suppression tests to evaluate the performance of a water mist system were conducted. The detailed measurements of the spray characteristics, i.e.,the Sauter Mean Diameter (SMD), the velocity and spray angle which are the main parameters considered in the study, were obtained by using LS-2000 Sizer. The amount of water consumed and the water flux density distribution over the cross section downstream the nozzle exit were measured by cup collector method. The operating pressure of the water mist nozzle is set to 0.5 MPa, the droplet SMD of 104 μm, the water flux density distribution from 0.71 to 8.47 L/(m2 .min), the average velocity of 2.14 m/s. The experimental results show that the averaged time required for extinguishment is 3.14 s, and the corresponding amount of water used during fire test is about 0.11 kg. The gas fire suppression system reduces the temperature in combustion chamber of the experimental apparatus below the ignition point of the gas, which can effectively avoid the occurrence of the gas fire in coal mine.

  18. Innovative gas diffusion layers and their water removal characteristics in PEM fuel cell cathode

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Kui; Zhou, Biao [Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Ont. (Canada)

    2007-06-20

    Liquid water transport is one of the key challenges regarding the water management in a proton exchange membrane (PEM) fuel cell. Conventional gas diffusion layers (GDLs) do not allow a well-organized liquid water flow from catalyst layer to gas flow channels. In this paper, three innovative GDLs with different micro-flow channels were proposed to solve liquid water flooding problems that conventional GDLs have. This paper also presents numerical investigations of air-water flow across the proposed innovative GDLs together with a serpentine gas flow channel on PEM fuel cell cathode by use of a commercial computational fluid dynamics (CFD) software package FLUENT. The results showed that different designs of GDLs will affect the liquid water flow patterns significantly, thus influencing the performance of PEM fuel cells. The detailed flow patterns of liquid water were shown. Several gas flow problems for the proposed different kinds of innovative GDLs were observed, and some useful suggestions were given through investigating the flow patterns inside the proposed GDLs. (author)

  19. Study of Plasma Treatment of Produced Water from Oil and Gas Exploration

    Science.gov (United States)

    Wright, Kamau

    Unconventional gas and hydraulic fracturing is helping to increase natural gas production, which is widely viewed in the U.S. as a key asset to bolstering a clean and energy-independent future. Safe and economical management and treatment of water produced during such processes remain of key importance. With the increase of hydrocarbon production and national shale gas production expected to increase threefold and account for nearly half of all natural gas produced by 2035, advanced water treatment and management processes must be investigated, to ensure water conservation and associated economic prudence. The state of the art of produced water treatment technologies is described including the efficacy of plasma to modulate the contents of such aqueous solutions, meeting target parameters and potentially enabling the operation of other treatment technologies. Among other effects, progress is presented on the enhancement of an arc-in-water system to remove bicarbonate ions and prevent the mineral fouling ability of water which causes formation of CaCO3 in heat exchangers and distillation units. Qualitative and quantitative treatment targets of produced water treatment are discussed. Experimental work is conducted to test theories and identify and reproduce favorable effects useful to treating wastewaters. Plasma arc-in-water systems demonstrated capability of producing bicarbonate-depleted wastewaters, with experiments with gas-field produced waters indicating that generation of H+ ions plays a greater role in bicarbonate ion removal than local heating. Tests showed abatement of bicarbonate ions from a range of 684--778 mg/L down to zero. Subsequent scaling/fouling tests with waters ranging from 0 to 500 mg/L bicarbonate ions, in the presence of high calcium ion concentrations, showed that scale thickness, as well as mass on a 1-kW heating element was an order of magnitude less for process water containing 100 mg/L bicarbonate ions compared to process water with 500

  20. SHALE GAS EXTRACTION AND WATER CONSUMPTION IN NORTH CAROLINA: A PRIMER

    Directory of Open Access Journals (Sweden)

    Manoj K. Jha

    2014-01-01

    Full Text Available About 25,000 acres of area underlying the Deep and Dan River Basins in North Carolina has been identified to contain large shale gas reservoirs that could be used for the natural gas production. This study attempted to quantify the impact of potential hydraulic fracturing (or fracking activities in the existing water resources of North Carolina. Supply and demand analysis was conducted using a water balance approach. Availability of surface water resources was quantified using the streamflow monitoring data of the surrounding area. A general assessment of the water demand for fracking was done using existing literature data and assumptions. Finally, a comparison was made between the water demand due to fracking and the water availability from nearby water sources. The preliminary analysis concluded that the surface water resources of North Caroline will not be affected at all as far as water quantity is concerned. However, whether extracting the shale gas of North Carolina is a good decision or not depends on the complete evaluation of the shale reservoirs and how well environmental impacts can be addressed.

  1. Gas exchange rates across the sediment-water and air-water interfaces in south San Francisco Bay

    Science.gov (United States)

    Hartman, Blayne; Hammond, Douglas E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water interface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.

  2. Flash Atomization: A New Concept to Control Combustion Instability in Water-Injected Gas Turbines

    Directory of Open Access Journals (Sweden)

    Vishwas Iyengar

    2012-01-01

    Full Text Available The objective of this work is to explore methods to reduce combustor rumble in a water-injected gas turbine. Attempts to use water injection as a means to reduce NOX emissions in gas turbines have been largely unsuccessful because of increased combustion instability levels. This pulsation causes chronic fretting, wear, and fatigue that damages combustor components. Of greater concern is that liberated fragments could cause extensive damage to the turbine section. Combustion instability can be tied to the insufficient atomization of injected water; large water droplets evaporate non-uniformly that lead to energy absorption in chaotic pulses. Added pulsation is amplified by the combustion process and acoustic resonance. Effervescent atomization, where gas bubbles are injected, is beneficial by producing finely atomized droplets; the gas bubbles burst as they exit the nozzles creating additional energy to disperse the liquid. A new concept for effervescent atomization dubbed “flash atomization” is presented where water is heated to just below its boiling point in the supply line so that some of it will flash to steam as it leaves the nozzle. An advantage of flash atomization is that available heat energy can be used rather than mechanical energy to compress injection gas for conventional effervescent atomization.

  3. Cavitation Rates in Water with Dissolved Gas and Other Impurities

    Institute of Scientific and Technical Information of China (English)

    Patrik Zima; Frantisek Marsík; Milan Sedlár

    2003-01-01

    Our objective is a better understanding of the role of physical properties of real fluids in the thermodynamics of cavitation in impure water. An extension to the classical homogenous nucleation theory suitable for mixtures is presented in attempt to address the discrepancy between the theoretical predictions and practical observations of cavitation rates in water at normal temperatures.The extension takes into account the non—equilibrium (dissipative) effects involved in nuclei formation through a substance dependent correction coefficient to be determined experimentally.The theory of thermodynamic fluctuations is applied to derive the work of formation of a bubble nucleus.The value of the correction coefficient is estimated using preliminary experimental data from a convergent-divergent nozzle. An application of the results to the numerical prediction of the cavitation zones in a radial-flow water pump is shown.

  4. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Edward; Bilirgen, Harun; DuPont, John

    2011-03-31

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: • An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing highmoisture, low rank coals. • Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. • Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. • Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. • Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. • Condensed flue gas water treatment needs and costs. • Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. • Results of cost-benefit studies of condensing heat exchangers.

  5. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Edward Levy; Harun Bilirgen; John DuPoint

    2011-03-31

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: (1) An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing high-moisture, low rank coals. (2) Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. (3) Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. (4) Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. (5) Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. (6) Condensed flue gas water treatment needs and costs. (7) Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. (8) Results of cost-benefit studies of condensing heat exchangers.

  6. Greenhouse gas emissions from alternative water supply processes in southern California, USA

    Science.gov (United States)

    Schneider, A.; Townsend-Small, A.

    2012-12-01

    Burgeoning population centers and declining hydrological resources have encouraged the development of alternative water treatment systems, including desalination and wastewater recycling. These processes currently provide potable water for millions of people and assist in satisfying agricultural and landscaping irrigation demands. There are a variety of alternative water production methods in place, and while they help to reduce the demands placed on aquifers, during their operation they are also significant sources of greenhouse gases. The environmental advantages of these alternative water production methods need to be carefully weighed against their energy footprints and greenhouse gas emissions profiles. This study measured the greenhouse gas emissions of a wastewater treatment and recycling facility in Orange County, California to get a more complete picture of the carbon footprint of the plant. We measured atmospheric emissions of CO2, CH4, and N2O throughout the water recycling process and at various times of the day and week. This allowed us to assemble a thorough, cross-sectional profile of greenhouse gas emissions from the facility. We then compared the measured emissions of the treatment plant to the modeled emissions of desalination plants in order to assess the relative carbon footprints of the two water production methods. Other water supply alternatives, including regional water importation, were also included in the comparison in order to provide a more complete understanding of the potential greenhouse gas emissions. Finally, we assessed the significance of wastewater treatment as an urban greenhouse gas source when compared to other known emissions in the region. This research offers a valuable tool for sustainable urban and regional development by providing planners with a quantified comparison of the carbon footprints of several water production options.

  7. Water management in capillary gas chromatographic air monitoring systems

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, J.F.; Tippler, A.; Seeley, I. [Perkin-Elmer Corp., Wilton, CT (United States)

    1995-12-31

    Determining the identity and quantities of volatile organic compounds in air samples at trace levels often requires large sample sizes to achieve part-per-billion (ppb) detection levels. Given the volatile nature of many of low molecular weight chemical species, some form of cooling or adsorbent trapping of the organics is required. Unfortunately, cooling air samples below ambient temperature causes large amounts of water to be removed along with the organics. This paper investigates the magnitude of the problem and examines various alternatives for managing trapped water. The application of some of these techniques is demonstrated in a method for determining volatile polar and non-polar compounds in ambient air.

  8. Membrane-Based Gas Traps for Ammonia, Freon-21, and Water Systems to Simplify Ground Processing

    Science.gov (United States)

    Ritchie, Stephen M. C.

    2003-01-01

    Gas traps are critical for the smooth operation of coolant loops because gas bubbles can cause loss of centrifugal pump prime, interference with sensor readings, inhibition of heat transfer, and blockage of passages to remote systems. Coolant loops are ubiquitous in space flight hardware, and thus there is a great need for this technology. Conventional gas traps will not function in micro-gravity due to the absence of buoyancy forces. Therefore, clever designs that make use of adhesion and momentum are required for adequate separation, preferable in a single pass. The gas traps currently used in water coolant loops on the International Space Station are composed of membrane tube sets in a shell. Each tube set is composed of a hydrophilic membrane (used for water transport and capture of bubbles) and a hydrophobic membrane (used for venting of air bubbles). For the hydrophilic membrane, there are two critical pressures, the pressure drop and the bubble pressure. The pressure drop is the decrease in system pressure across the gas trap. The bubble pressure is the pressure required for air bubbles to pass across the water filled membrane. A significant difference between these pressures is needed to ensure complete capture of air bubbles in a single pass. Bubbles trapped by the device adsorb on the hydrophobic membrane in the interior of the hydrophilic membrane tube. After adsorption, the air is vented due to a pressure drop of approximately 1 atmosphere across the membrane. For water systems, the air is vented to the ambient (cabin). Because water vapor can also transport across the hydrophobic membrane, it is critical that a minimum surface area is used to avoid excessive water loss (would like to have a closed loop for the coolant). The currently used gas traps only provide a difference in pressure drop and bubble pressure of 3-4 psid. This makes the gas traps susceptible to failure at high bubble loading and if gas venting is impaired. One mechanism for the latter

  9. The Assessment of Instruments for Detecting Surface Water Spills Associated with Oil and Gas Operations

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Aubrey E. [West Virginia Univ., Morgantown, WV (United States); National Energy Technology Lab. (NETL), Morgantown, WV (United States); U.S. Bureau of Reclamation, Albuquerque, NM (United States); Hopkinson, Leslie [West Virginia Univ., Morgantown, WV (United States); Soeder, Daniel [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2016-12-02

    Surface water and groundwater risks associated with unconventional oil and gas development result from potential spills of the large volumes of chemicals stored on-site during drilling and hydraulic fracturing operations, and the return to the surface of significant quantities of saline water produced during oil or gas well production. To better identify and mitigate risks, watershed models and tools are needed to evaluate the dispersion of pollutants in possible spill scenarios. This information may be used to determine the placement of in-stream water-quality monitoring instruments and to develop early-warning systems and emergency plans. A chemical dispersion model has been used to estimate the contaminant signal for in-stream measurements. Spills associated with oil and gas operations were identified within the Susquehanna River Basin Commission’s Remote Water Quality Monitoring Network. The volume of some contaminants was found to be sufficient to affect the water quality of certain drainage areas. The most commonly spilled compounds and expected peak concentrations at monitoring stations were used in laboratory experiments to determine if a signal could be detected and positively identified using standard water-quality monitoring equipment. The results were compared to historical data and baseline observations of water quality parameters, and showed that the chemicals tested do commonly affect water quality parameters. This work is an effort to demonstrate that hydrologic and water quality models may be applied to improve the placement of in-stream water quality monitoring devices. This information may increase the capability of early-warning systems to alert community health and environmental agencies of surface water spills associated with unconventional oil and gas operations.

  10. Effect and mechanism of coking residual ammonia water treating by flue gas

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The treatment of coking residual ammonia water has been a bigdifficult problem at home and abroad, and there is no breakthrough research achievement in the past. The invention patent "The method of treating all coking wastewater or treating coking residual ammonia water by flue gas" has been successfully used in Huaian Steel Works for high concentration and organic industry wastewater treatment. Not only can it realize the wastewater zero discharge, but also the wastewater treatment has an effect of de-sulfur and de-nitrogen for flue gas. So that the flue gas exhaustcan meet the requirement of emission standard. The mass transfer and heat transfer, fly ash absorption and coagulation, acid and alkali neutralization reaction, catalysis oxidation and reduction reaction in flue gas would be the major factors.

  11. Effects of Irrigating with Treated Oil and Gas Product Water on Crop Biomass and Soil Permeability

    Energy Technology Data Exchange (ETDEWEB)

    Terry Brown; Jeffrey Morris; Patrick Richards; Joel Mason

    2010-09-30

    Demonstrating effective treatment technologies and beneficial uses for oil and gas produced water is essential for producers who must meet environmental standards and deal with high costs associated with produced water management. Proven, effective produced-water treatment technologies coupled with comprehensive data regarding blending ratios for productive long-term irrigation will improve the state-of-knowledge surrounding produced-water management. Effective produced-water management scenarios such as cost-effective treatment and irrigation will discourage discharge practices that result in legal battles between stakeholder entities. The goal of this work is to determine the optimal blending ratio required for irrigating crops with CBNG and conventional oil and gas produced water treated by ion exchange (IX), reverse osmosis (RO), or electro-dialysis reversal (EDR) in order to maintain the long term physical integrity of soils and to achieve normal crop production. The soils treated with CBNG produced water were characterized with significantly lower SAR values compared to those impacted with conventional oil and gas produced water. The CBNG produced water treated with RO at the 100% treatment level was significantly different from the untreated produced water, while the 25%, 50% and 75% water treatment levels were not significantly different from the untreated water. Conventional oil and gas produced water treated with EDR and RO showed comparable SAR results for the water treatment technologies. There was no significant difference between the 100% treated produced water and the control (river water). The EDR water treatment resulted with differences at each level of treatment, which were similar to RO treated conventional oil and gas water. The 100% treated water had SAR values significantly lower than the 75% and 50% treatments, which were similar (not significantly different). The results of the greenhouse irrigation study found the differences in biomass

  12. Estimating national water use associated with unconventional oil and gas development

    Science.gov (United States)

    Carter, Janet M.; Macek-Rowland, Kathleen M.; Thamke, Joanna N.; Delzer, Gregory C.

    2016-05-18

    The U.S. Geological Survey’s (USGS) Water Availability and Use Science Program (WAUSP) goals are to provide a more accurate assessment of the status of the water resources of the United States and assist in the determination of the quantity and quality of water that is available for beneficial uses. These assessments would identify long-term trends or changes in water availability since the 1950s in the United States and help to develop the basis for an improved ability to forecast water avail- ability for future economic, energy-production, and environmental uses. The National Water Census (http://water.usgs.gov/watercensus/), a research program of the WAUSP, supports studies to develop new water accounting tools and assess water availability at the regional and national scales. Studies supported by this program target focus areas with identified water availability concerns and topical science themes related to the use of water within a specific type of environmental setting. The topical study described in this fact sheet will focus on understanding the relation between production of unconventional oil and gas (UOG) for energy and the water needed to produce and sustain this type of energy development. This relation applies to the life-cycle of renewable and nonrenewable forms of UOG energy and includes extraction, production, refinement, delivery, and disposal of waste byproducts. Water-use data and models derived from this topical study will be applied to other similar oil and gas plays within the United States to help resource managers assess and account for water used or needed in these areas. Additionally, the results from this topical study will be used to further refine the methods used in compiling water-use data for selected categories (for example, mining, domestic self-supplied, public supply, and wastewater) in the USGS’s 5-year national water-use estimates reports (http://water.usgs.gov/watuse/).

  13. Estimating greenhouse gas fluxes from constructed wetlands used for water quality improvement

    OpenAIRE

    Sukanda Chuersuwan; Pongthep Suwanwaree; Nares Chuersuwan

    2014-01-01

    Methane (CH4 ), nitrous oxide (N2O) and carbon dioxide (CO2 ) fluxes were evaluated from constructed wetlands (CWs) used to improve domestic wastewater quality. Experiments employed subsurface flow (SF) and free water surface flow (FWS) CWs planted with Cyperus spp. Results showed seasonal fluctuations of greenhouse gas fluxes. Greenhouse gas fluxes from SF-CWs and FWS-CWS were significantly different (p

  14. Shale gas produced water treatment using innovative microbial capacitive desalination cell.

    Science.gov (United States)

    Stoll, Zachary A; Forrestal, Casey; Ren, Zhiyong Jason; Xu, Pei

    2015-01-01

    The rapid development of unconventional oil and gas production has generated large amounts of wastewater for disposal, raising significant environmental and public health concerns. Treatment and beneficial use of produced water presents many challenges due to its high concentrations of petroleum hydrocarbons and salinity. The objectives of this study were to investigate the feasibility of treating actual shale gas produced water using a bioelectrochemical system integrated with capacitive deionization-a microbial capacitive desalination cell (MCDC). Microbial degradation of organic compounds in the anode generated an electric potential that drove the desalination of produced water. Sorption and biodegradation resulted in a combined organic removal rate of 6.4 mg dissolved organic carbon per hour in the reactor, and the MCDC removed 36 mg salt per gram of carbon electrode per hour from produced water. This study is a proof-of-concept that the MCDC can be used to combine organic degradation with desalination of contaminated water without external energy input.

  15. Coal seam gas water: potential hazards and exposure pathways in Queensland.

    Science.gov (United States)

    Navi, Maryam; Skelly, Chris; Taulis, Mauricio; Nasiri, Shahram

    2015-01-01

    The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment.

  16. Development and Validation of a Gas-Fired Residential Heat Pump Water Heater - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Garrabrant; Roger Stout; Paul Glanville; Janice Fitzgerald; Chris Keinath

    2013-01-21

    For gas-fired residential water heating, the U.S. and Canada is predominantly supplied by minimum efficiency storage water heaters with Energy Factors (EF) in the range of 0.59 to 0.62. Higher efficiency and higher cost ($700 - $2,000) options serve about 15% of the market, but still have EFs below 1.0, ranging from 0.65 to 0.95. To develop a new class of water heating products that exceeds the traditional limit of thermal efficiency, the project team designed and demonstrated a packaged water heater driven by a gas-fired ammonia-water absorption heat pump. This gas-fired heat pump water heater can achieve EFs of 1.3 or higher, at a consumer cost of $2,000 or less. Led by Stone Mountain Technologies Inc. (SMTI), with support from A.O. Smith, the Gas Technology Institute (GTI), and Georgia Tech, the cross-functional team completed research and development tasks including cycle modeling, breadboard evaluation of two cycles and two heat exchanger classes, heat pump/storage tank integration, compact solution pump development, combustion system specification, and evaluation of packaged prototype GHPWHs. The heat pump system extracts low grade heat from the ambient air and produces high grade heat suitable for heating water in a storage tank for domestic use. Product features that include conventional installation practices, standard footprint and reasonable economic payback, position the technology to gain significant market penetration, resulting in a large reduction of energy use and greenhouse gas emissions from domestic hot water production.

  17. Simultaneous removal of water and BTEX from feed gas for a cryogenic plant

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.; Lee, S.; Evans, M.; Chen, R.

    1999-07-01

    The removal of water and benzene, toluene, ethyl benzene, xylene (BTEX) from the feed gas of a cryogenic plant is critical in order to avoid precipitation of these components in the cold section of the plant. The design of the Hannibal Gas Plant in Sfax, Tunisia, accomplishes the removal of water and BTEX simultaneously. The plant receives 7.1 million Nm{sub 3}/day of feed gas and produces high heating value pipeline quality sales gas by removing nitrogen in the cold box. A methyl diethanol amine (MDEA) treating system at the front end of the plant is designed to remove carbon dioxide. The glycol system takes the saturated gas from the MDEA contactor and reduces the water content to 7 lb/MMscf. The glycol system is also designed to remove more than half of the BTEX from the feed gas so that these aromatic components will not precipitate in the cold section of the plant. GPA experimental data were used to fit the interaction parameters for the computer simulator used to design the glycol system. The results of the plant performance test verify the validity of the design.

  18. Experimental study on hydrodynamic behaviors of high-speed gas jets in still water

    Institute of Scientific and Technical Information of China (English)

    Zhenqing Dai; Boyi Wang; Longxi Qi; Honghui Shi

    2006-01-01

    The present paper describes experimental investigation on the flow pattern and hydrodynamic effect of underwater gas jets from supersonic and sonic nozzles operated in correct- and imperfect expansion conditions. The flow visualizations show that jetting is the flow regime for the submerged gas injection at a high speed in the parameter range under consideration. The obtained results indicate that high-speed gas jets in still water induce large pressure pulsations upstream of the nozzle exit and the presence of shock-cell structure in the over-and under-expanded jets leads to an increase in the intensity of the jet-induced hydrodynamic pressure.

  19. Oil and gas company policy regarding the concept of sustainable development (water resources)

    Science.gov (United States)

    Matyugina, E. G.; Pogharnitskaya, O. V.; Grinkevich, L. S.; Belozerova, D. S.; Strelnikova, A. B.

    2016-03-01

    The paper considers oil and gas companies implementing the strategy of sustainable development. Being vital to the national economy, oil and gas companies have a significant impact on the environment. Having analyzed the statistical data, the authors state that the leading Russian oil and gas companies contribute to the industry dynamics and conduct eco-friendly production practices. The environmental component is reported to be integrated in production, HR, information and other company policies, which results in “greening” both economic cooperation and place of production. The authors report the inverse relation between production dynamics and significance of the impact on water resources.

  20. Nonzero Ideal Gas Contribution to the Surface Tension of Water.

    Science.gov (United States)

    Sega, Marcello; Fábián, Balázs; Jedlovszky, Pál

    2017-06-15

    Surface tension, the tendency of fluid interfaces to behave elastically and minimize their surface, is routinely calculated as the difference between the lateral and normal components of the pressure or, invoking isotropy in momentum space, of the virial tensor. Here we show that the anisotropy of the kinetic energy tensor close to a liquid-vapor interface can be responsible for a large part of its surface tension (about 15% for water, independent from temperature).

  1. Life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well.

    Science.gov (United States)

    Jiang, Mohan; Hendrickson, Chris T; VanBriesen, Jeanne M

    2014-01-01

    This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input-output life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20,000 m(3) (with a range from 6700 to 33,000 m(3)) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300-3000 kg N-eq eutrophication potential, 900-23,000 kg 2,4D-eq freshwater ecotoxicity potential, 0-370 kg benzene-eq carcinogenic potential, and 2800-71,000 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well wastewater is

  2. Life Cycle Water Consumption and Wastewater Generation Impacts of a Marcellus Shale Gas Well

    Science.gov (United States)

    2013-01-01

    This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input–output life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20 000 m3 (with a range from 6700 to 33 000 m3) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300–3000 kg N-eq eutrophication potential, 900–23 000 kg 2,4D-eq freshwater ecotoxicity potential, 0–370 kg benzene-eq carcinogenic potential, and 2800–71 000 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well

  3. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corp. , Columbus, Ohio. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    The Solar Energy System located at the Columbia Gas Corporation, Columbus, Ohio, has 2978 ft/sup 2/ of Honeywell single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/h Bryan water-tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton Arkla hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts are included from the site files, specification references, drawings, installation, operation and maintenance instructions.

  4. Density functional theory study on water-gas-shift reaction over molybdenum disulfide

    DEFF Research Database (Denmark)

    Shi, X. R.; Wang, Shengguang; Hu, J.

    2009-01-01

    Density functional theory calculations have been carried out to investigate the adsorption of reaction intermediates appearing during water-gas-shift reaction at the sulfur covered MoS2 (1 0 0)surfaces, Mo-termination with 37.5% S coverage and S-termination with 50% S coverage using periodic slabs....... The pathway for water-gas-shift reaction on both terminations has been carefully studied where the most favorable reaction path precedes the redox mechanism, namely the reaction takes place as follows: CO + H2O --> CO + OH + H --> CO + O + 2H --> CO2 + H-2. The most likely reaction candidates for the formate...

  5. Multiple-pressure-tapped core holder combined with X-ray computed tomography scanning for gas-water permeability measurements of methane-hydrate-bearing sediments

    Science.gov (United States)

    Konno, Yoshihiro; Jin, Yusuke; Uchiumi, Takashi; Nagao, Jiro

    2013-06-01

    We present a novel setup for measuring the effective gas-water permeability of methane-hydrate-bearing sediments. We developed a core holder with multiple pressure taps for measuring the pressure gradient of the gas and water phases. The gas-water flooding process was simultaneously detected using an X-ray computed tomography scanner. We successfully measured the effective gas-water permeability of an artificial sandy core with methane hydrate during the gas-water flooding test.

  6. Information meeting: construction of gas and water pipelines; Informationsveranstaltung: Bau von Gas- und Wasserrohrleitungen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Already published journal articles added in a conference proceeding on following topics: Regulatories, construction regulations, fittings, quality requirements and corrosion protection. Water pipes and pressure testing and desinfection.(GL) [German] Teilweise bereits veroeffentlichte Zeitschriftenartikel nochmals in einem Konferenzband zusammengefuegt zu folgenden Themen: Regelwerke, Baurichtlinien, Anschluesse, Qualitaetsanforderungen und Korrosonsschutz. Wasserrohrleitungen und deren Druckpruefung und Desinfektion.(GL)

  7. Treatment of waste water from flue gas cleaning; Behandlung von Abwasser der Rauchgasreinigung

    Energy Technology Data Exchange (ETDEWEB)

    Ogiermann, Klaus; Meyerhoff, Thomas [Berkefeld - VWS Deutschland GmbH, Celle (Germany); Hagen, Klaus [Berkefeld - VWS Deutschland GmbH, Bayreuth (Germany); Basabe, Juan Luis [HPD Process Engineering S.A., Bilbao (Spain); Vendrup, Michael [Krueger A/S, Soeborg (Denmark)

    2012-11-01

    Strict limits must be adhered to for treating waste water incurred during flue gas desulphurisation (FGD). One and two-stage precipitation processes have proven themselves in FGD waste water treatment. Metals can be removed with the MetClean {sup registered} process. Another option is evaporation. Waste water ZLD systems (Zero Liquid Discharge) recover, via a falling film evaporator with subsequent crystallisation, more than 98 % of the water and produce, aside from the condensate, only solid material that can be disposed of in landfill. A further development, named ZLD CoLD trademark, significantly reduces the investment and operating costs of this solution. (orig.)

  8. Managing produced water from coal seam gas projects: implications for an emerging industry in Australia.

    Science.gov (United States)

    Davies, Peter J; Gore, Damian B; Khan, Stuart J

    2015-07-01

    This paper reviews the environmental problems, impacts and risks associated with the generation and disposal of produced water by the emerging coal seam gas (CSG) industry and how it may be relevant to Australia and similar physical settings. With only limited independent research on the potential environmental impacts of produced water, is it necessary for industry and government policy makers and regulators to draw upon the experiences of related endeavours such as mining and groundwater extraction accepting that the conclusions may not always be directly transferrable. CSG is widely touted in Australia as having the potential to provide significant economic and energy security benefits, yet the environmental and health policies and the planning and regulatory setting are yet to mature and are continuing to evolve amidst ongoing social and environmental concerns and political indecision. In this review, produced water has been defined as water that is brought to the land surface during the process of recovering methane gas from coal seams and includes water sourced from CSG wells as well as flowback water associated with drilling, hydraulic fracturing and gas extraction. A brief overview of produced water generation, its characteristics and environmental issues is provided. A review of past lessons and identification of potential risks, including disposal options, is included to assist in planning and management of this industry.

  9. Hydrogen production by absorption enhanced water gas shift (AEWGS)

    Energy Technology Data Exchange (ETDEWEB)

    Escobedo Bretado, Miguel A. [Facultad de Ciencias Quimicas, Universidad Juarez del Estado de Durango, Ave. Veterinaria s/n, Circuito Universitario, Durango 34120 (Mexico); Departamento de Quimica de Materiales, Centro de Investigacion en Materiales Avanzados, S.C. Miguel de Cervantes 120, Chihuahua, Chih. 31109 (Mexico); Delgado Vigil, Manuel D.; Gutierrez, Jesus Salinas; Lopez Ortiz, Alejandro; Collins-Martinez, Virginia [Departamento de Quimica de Materiales, Centro de Investigacion en Materiales Avanzados, S.C. Miguel de Cervantes 120, Chihuahua, Chih. 31109 (Mexico)

    2010-11-15

    AEWGS is a reaction that combines the WGS reaction and CO{sub 2} capture by a solid absorbent to produce high purity H{sub 2} from synthesis gas in one single step at 600-800 C. This reactor system, if homogeneous, would not require a catalyst. However, previous research on this concept was not conclusive, since a steel reactor was used and reactor walls were suspected to act as catalyst. Therefore, there is a need to address this issue and to select and evaluate suitable CO{sub 2} absorbents for this concept. AEWGS was studied using a quartz-made fixed-bed reactor at; SV = 3000 h{sup -1}, feed; 5% CO, 15% H{sub 2}O, balance He-N{sub 2} at 600 C, 1 atm. CO{sub 2} absorbents tested were CaO*MgO, and Na{sub 2}ZrO{sub 3}. Empty quartz-reactor tests leaded to conclude that a catalyst is needed for the WGS at temperatures of interest. A 97% H{sub 2} product was obtained with calcined dolomite suggesting this last to act as a WGS catalyst. (author)

  10. Delineation of ground-water contamination using soil-gas analyses near Jackson, Tennessee

    Science.gov (United States)

    Lee, R.W.

    1991-01-01

    An investigation of the ground-water resources near Jackson, West Tennessee, was conducted during 1988-89. The study included determination of the occurrence of contaminants in the shallow aquifer using soil-gas analyses in the unsaturated zone. Between 1980 and 1988, an underground fuel-storage tank leaked about 3,000 gallons of unleaded fuel to the water table about 4 feet below land surface. A survey of soil gas using a gas chromatograph equipped with a photoionization detector showed concentrations of volatile organic compounds greater than IO, 000 parts per million near the leak These compounds were detected in an area about 240 feet long and 110 feet wide extending west from the point source. The chromatograms provided two distinct 'fingerprints' of volatile organic compounds. The first revealed the presence of benzene, toluene, andxylenes, which are constituents of unleaded fuel, in addition to other volatile compounds, in soil gas in the area near the leak The second did not reveal any detectable benzene, toluene, or xylenes in the soil-gas samples, but showed the presence of other unidentified volatile organic compounds in soil gas north of the storage tank. The distribution of total concentrations of volatile organic compounds in the unsaturated zone indicated that a second plume about 200 feet long and 90 feet wide was present about 100 feet north of the storage tank The second plume could have been the result of previous activities at this site during the 1950's or earlier. Activities at the site are believed to have included storage of solvents used at the nearby railyard and flushing of tanks containing tar onto a gravel-covered parking area. The delineation of these plumes has shown that soil-gas analyses can be a useful technique for identifying areas of contamination with volatile organic compounds in shallow water-table aquifers and may have broad applications in similar situations where the water table is relatively close to the surface.

  11. Impacts of Coal Seam Gas (Coal Bed Methane) and Coal Mining on Water Resources in Australia

    Science.gov (United States)

    Post, D. A.

    2013-12-01

    Mining of coal bed methane deposits (termed ';coal seam gas' in Australia) is a rapidly growing source of natural gas in Australia. Indeed, expansion of the industry is occurring so quickly that in some cases, legislation is struggling to keep up with this expansion. Perhaps because of this, community concern about the impacts of coal seam gas development is very strong. Responding to these concerns, the Australian Government has recently established an Independent Expert Scientific Committee (IESC) to provide advice to the Commonwealth and state regulators on potential water-related impacts of coal seam gas and large coal mining developments. In order to provide the underlying science to the IESC, a program of ';bioregional assessments' has been implemented. One aim of these bioregional assessments is to improve our understanding of the connectivity between the impacts of coal seam gas extraction and groundwater aquifers, as well as their connection to surface water. A bioregional assessment can be defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion, with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are now being carried out across large portions of eastern Australia which are underlain by coal reserves. This presentation will provide an overview of the issues related to the impacts of coal seam gas and coal mining on water resources in Australia. The methodology of undertaking bioregional assessments will be described, and the application of this methodology to six priority bioregions in eastern Australia will be detailed. Preliminary results of the program of research to date will be assessed in light of the requirements of the IESC to provide independent advice to the Commonwealth and State governments. Finally, parallels between the expansion of the industry in Australia with that

  12. The Impact of Thermal Conductivity and Diffusion Rates on Water Vapor Transport through Gas Diffusion Layers

    CERN Document Server

    Burlatsky, S F; Gummallaa, M; Condita, D; Liua, F

    2013-01-01

    Water management in a hydrogen polymer electrolyte membrane (PEM) fuel cell is critical for performance. The impact of thermal conductivity and water vapor diffusion coefficients in a gas diffusion layer (GDL) has been studied by a mathematical model. The fraction of product water that is removed in the vapour phase through the GDL as a function of GDL properties and operating conditions has been calculated and discussed. Furthermore, the current model enables identification of conditions when condensation occurs in each GDL component and calculation of temperature gradient across the interface between different layers, providing insight into the overall mechanism of water transport in a given cell design. Water transport mode and condensation conditions in the GDL components depend on the combination of water vapor diffusion coefficients and thermal conductivities of the GDL components. Different types of GDL and water removal scenarios have been identified and related to experimentally-determined GDL proper...

  13. Physical simulation of gas reservoir formation in the Liwan 3-1 deep-water gas field in the Baiyun sag, Pearl River Mouth Basin

    Directory of Open Access Journals (Sweden)

    Gang Gao

    2015-01-01

    Full Text Available To figure out the process and controlling factors of gas reservoir formation in deep-waters, based on an analysis of geological features, source of natural gas and process of reservoir formation in the Liwan 3-1 gas field, physical simulation experiment of the gas reservoir formation process has been performed, consequently, pattern and features of gas reservoir formation in the Baiyun sag has been found out. The results of the experiment show that: ① the formation of the Liwan 3-1 faulted anticline gas field is closely related to the longstanding active large faults, where natural gas is composed of a high proportion of hydrocarbons, a small amount of non-hydrocarbons, and the wet gas generated during highly mature stage shows obvious vertical migration signs; ② liquid hydrocarbons associated with natural gas there are derived from source rock of the Enping & Zhuhai Formation, whereas natural gas comes mainly from source rock of the Enping Formation, and source rock of the Wenchang Formation made a little contribution during the early Eocene period as well; ③ although there was gas migration and accumulation, yet most of the natural gas mainly scattered and dispersed due to the stronger activity of faults in the early period; later as fault activity gradually weakened, gas started to accumulate into reservoirs in the Baiyun sag; ④ there is stronger vertical migration of oil and gas than lateral migration, and the places where fault links effective source rocks with reservoirs are most likely for gas accumulation; ⑤ effective temporal-spatial coupling of source-fault-reservoir in late stage is the key to gas reservoir formation in the Baiyun sag; ⑥ the nearer the distance from a trap to a large-scale fault and hydrocarbon source kitchen, the more likely gas may accumulate in the trap in late stage, therefore gas accumulation efficiency is much lower for the traps which are far away from large-scale faults and hydrocarbon source

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

    Science.gov (United States)

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

    2014-01-01

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

  15. Water intensity assessment of shale gas resources in the Wattenberg field in northeastern Colorado.

    Science.gov (United States)

    Goodwin, Stephen; Carlson, Ken; Knox, Ken; Douglas, Caleb; Rein, Luke

    2014-05-20

    Efficient use of water, particularly in the western U.S., is an increasingly important aspect of many activities including agriculture, urban, and industry. As the population increases and agriculture and energy needs continue to rise, the pressure on water and other natural resources is expected to intensify. Recent advances in technology have stimulated growth in oil and gas development, as well as increasing the industry's need for water resources. This study provides an analysis of how efficiently water resources are used for unconventional shale development in Northeastern Colorado. The study is focused on the Wattenberg Field in the Denver-Julesberg Basin. The 2000 square mile field located in a semiarid climate with competing agriculture, municipal, and industrial water demands was one of the first fields where widespread use of hydraulic fracturing was implemented. The consumptive water intensity is measured using a ratio of the net water consumption and the net energy recovery and is used to measure how efficiently water is used for energy extraction. The water and energy use as well as energy recovery data were collected from 200 Noble Energy Inc. wells to estimate the consumptive water intensity. The consumptive water intensity of unconventional shale in the Wattenberg is compared with the consumptive water intensity for extraction of other fuels for other energy sources including coal, natural gas, oil, nuclear, and renewables. 1.4 to 7.5 million gallons is required to drill and hydraulically fracture horizontal wells before energy is extracted in the Wattenberg Field. However, when the large short-term total freshwater-water use is normalized to the amount of energy produced over the lifespan of a well, the consumptive water intensity is estimated to be between 1.8 and 2.7 gal/MMBtu and is similar to surface coal mining.

  16. Difference Of Evaporation and Boiling for Heterogeneous Water Droplets in a High-Temperature Gas

    Directory of Open Access Journals (Sweden)

    Legros Jean Claude

    2015-01-01

    Full Text Available Experimental investigation of vapor formation was carried out on water droplets on fixed graphite substrate and heterogeneous droplets (containing solid single inclusions when heating in high-temperature gas. High-speed video shooting (up to 105 frames per second, optical method (Particle Image Velocimetry and TEMA Automotive software were used. We revealed two phase change mechanisms of heterogeneous liquid droplets. Effect of evaporation and boiling on evaporation times of water droplets was determined.

  17. A simple technique for continuous measurement of time-variable gas transfer in surface waters

    Science.gov (United States)

    Bohlke, Johnkarl F.; Harvey, Judson W.; Busenberg, Eurybiades; Tobias, Craig R.

    2009-01-01

    Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating wholeecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the SF6 gas tracer approach that can be used concurrently while collecting other dissolved gas samples for dissolved gas mass balance studies in streams. It consists of continuously metering SF6-saturated water directly into the stream at a low rate of flow. This approach has advantages over pulse injection of aqueous solutions or bubbling large amounts of SF6 into the stream. By adding the SF6 as a saturated solution, we minimize the possibility that other dissolved gas measurements are affected by sparging and/or bubble injecta. Because the SF6 is added continuously we have a record of changing gas transfer velocity (GTV) that is contemporaneous with the sampling of other nonconservative ambient dissolved gases. Over a single diel period, a 30% variation in GTV was observed in a second-order stream (Sugar Creek, Indiana, USA). The changing GTV could be attributed in part to changes in temperature and windspeed that occurred on hourly to diel timescales.

  18. 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.

  19. Total dissolved gas, barometric pressure, and water temperature data, lower Columbia River, Oregon and Washington, 1996

    Science.gov (United States)

    Tanner, Dwight Q.; Harrison, Howard E.; McKenzie, Stuart W.

    1996-01-01

    Increased levels of total dissolved gas pressure can cause gas-bubble trauma in fish downstream from dams on the Columbia River. In cooperation with the U.S. Army Corps of Engineers, the U.S. Geological Survey collected data on total dissolved gas pressure, barometric pressure, water temperature, and dissolved oxygen pressure at 11 stations on the lower Columbia River from the John Day forebay (river mile 215.6) to Wauna Mill (river mile 41.9) from March to September 1996. Methods of data collection, review, and processing are described in this report. Summaries of daily minimum, maximum, and mean hourly values are presented for total dissolved gas pressure, barometric pressure, and water temperature. Hourly values for these parameters are presented graphically. Dissolved oxygen data are not presented in this report because the quality-control data show that the data have poor precision and high bias. Suggested changes to monitoring procedures for future studies include (1) improved calibration procedures for total dissolved gas and dissolved oxygen to better define accuracy at elevated levels of supersaturation and (2) equipping dissolved oxygen sensors with stirrers because river velocities at the shoreline monitoring stations probably cannot maintain an adequate flow of water across the membrane surface of the dissolved oxygen sensor.

  20. Shale gas produced water treatment using innovative microbial capacitive desalination cell

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Zachary A. [New Mexico State University, Las Cruces, NM 88003 (United States); Forrestal, Casey [University of Colorado Boulder, Boulder, CO 80309 (United States); Ren, Zhiyong Jason, E-mail: jason.ren@colorado.edu [University of Colorado Boulder, Boulder, CO 80309 (United States); Xu, Pei, E-mail: wxpei@hotmail.com [New Mexico State University, Las Cruces, NM 88003 (United States)

    2015-02-11

    Highlights: • Actual shale gas produced water was treated with no external energy input. • Biodegradation of organics generated stable voltages for desalination. • On average, 36 mg TDS per g activated carbon was removed in 1 h. • A maximum organic removal rate of 6.4 mg DOC per hour was achieved in the reactor. - Abstract: The rapid development of unconventional oil and gas production has generated large amounts of wastewater for disposal, raising significant environmental and public health concerns. Treatment and beneficial use of produced water presents many challenges due to its high concentrations of petroleum hydrocarbons and salinity. The objectives of this study were to investigate the feasibility of treating actual shale gas produced water using a bioelectrochemical system integrated with capacitive deionization—a microbial capacitive desalination cell (MCDC). Microbial degradation of organic compounds in the anode generated an electric potential that drove the desalination of produced water. Sorption and biodegradation resulted in a combined organic removal rate of 6.4 mg dissolved organic carbon per hour in the reactor, and the MCDC removed 36 mg salt per gram of carbon electrode per hour from produced water. This study is a proof-of-concept that the MCDC can be used to combine organic degradation with desalination of contaminated water without external energy input.

  1. Alteration of natural (37)Ar activity concentration in the subsurface by gas transport and water infiltration.

    Science.gov (United States)

    Guillon, Sophie; Sun, Yunwei; Purtschert, Roland; Raghoo, Lauren; Pili, Eric; Carrigan, Charles R

    2016-05-01

    High (37)Ar activity concentration in soil gas is proposed as a key evidence for the detection of underground nuclear explosion by the Comprehensive Nuclear Test-Ban Treaty. However, such a detection is challenged by the natural background of (37)Ar in the subsurface, mainly due to Ca activation by cosmic rays. A better understanding and improved capability to predict (37)Ar activity concentration in the subsurface and its spatial and temporal variability is thus required. A numerical model integrating (37)Ar production and transport in the subsurface is developed, including variable soil water content and water infiltration at the surface. A parameterized equation for (37)Ar production in the first 15 m below the surface is studied, taking into account the major production reactions and the moderation effect of soil water content. Using sensitivity analysis and uncertainty quantification, a realistic and comprehensive probability distribution of natural (37)Ar activity concentrations in soil gas is proposed, including the effects of water infiltration. Site location and soil composition are identified as the parameters allowing for a most effective reduction of the possible range of (37)Ar activity concentrations. The influence of soil water content on (37)Ar production is shown to be negligible to first order, while (37)Ar activity concentration in soil gas and its temporal variability appear to be strongly influenced by transient water infiltration events. These results will be used as a basis for practical CTBTO concepts of operation during an OSI.

  2. Malignant human cell transformation of Marcellus shale gas drilling flow back water

    Science.gov (United States)

    Yao, Yixin; Chen, Tingting; Shen, Steven S.; Niu, Yingmei; DesMarais, Thomas L; Linn, Reka; Saunders, Eric; Fan, Zhihua; Lioy, Paul; Kluz, Thomas; Chen, Lung-Chi; Wu, Zhuangchun; Costa, Max

    2015-01-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation is known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these waste waters, flow back water from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy / energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC50 values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6 weeks with flow back waters produced colony formation in soft agar that was concentration dependant. In addition, flow back water-transformed BEAS-2B cells show a better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. PMID:26210350

  3. Geochemical and Strontium Isotope Characterization of Produced Waters from Marcellus Shale Natural Gas Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth C. Chapman,† Rosemary C. Capo,† Brian W. Stewart,*,† Carl S. Kirby,‡ Richard W. Hammack,§

    2012-02-24

    Extraction of natural gas by hydraulic fracturing of the Middle Devonian Marcellus Shale, a major gas-bearing unit in the Appalachian Basin, results in significant quantities of produced water containing high total dissolved solids (TDS). We carried out a strontium (Sr) isotope investigation to determine the utility of Sr isotopes in identifying and quantifying the interaction of Marcellus Formation produced waters with other waters in the Appalachian Basin in the event of an accidental release, and to provide information about the source of the dissolved solids. Strontium isotopic ratios of Marcellus produced waters collected over a geographic range of ∼375 km from southwestern to northeastern Pennsylvania define a relatively narrow set of values (εSr SW = +13.8 to +41.6, where εSr SW is the deviation of the 87Sr/86Sr ratio from that of seawater in parts per 104); this isotopic range falls above that of Middle Devonian seawater, and is distinct from most western Pennsylvania acid mine drainage and Upper Devonian Venango Group oil and gas brines. The uniformity of the isotope ratios suggests a basin-wide source of dissolved solids with a component that is more radiogenic than seawater. Mixing models indicate that Sr isotope ratios can be used to sensitively differentiate between Marcellus Formation produced water and other potential sources of TDS into ground or surface waters.

  4. Determination of phenoxy acid herbicides in water by electron-capture and microcoulometric gas chromatography

    Science.gov (United States)

    Goerlitz, D.F.; Lamar, William L.

    1967-01-01

    A sensitive gas chromatographic method using microcoulometric titration and electron-capture detection for the analysis of 2,4-D, silvex, 2,4,5-T, and other phenoxy acid herbicides in water is described. The herbicides are extracted from unfiltered water samples (800-1,000 ml) by use of ethyl ether ; then the herbicides are concentrated and esterilied. To allow the analyst a choice, two esterilication procedures--using either boron trifluoride-methanol or diazomethane--are evaluated. Microcoulometric gas chromatography is specific for the detection of halogenated compounds such as the phenoxy acid herbicides whereas it does not respond to nonhalogenated components. Microcoulometric gas chromatography requires care and patience. It is not convenient for rapid screening of l-liter samples that contain less than 1 microgram of the herbicide. Although electroncapture gas chromatography is less selective and more critically affected by interfering substances, it is, nevertheless, convenient and more sensitive than microcoulometric gas chromatography. Two different liquid phases are used in the gas chromatographic columns--DC-200 silicone in one column and QF-1 silicone in the other. The performance of both columns is improved by the addition of Carbowax 20M. The Gas Chrom Q support is coated with the liquid phases by the 'frontal-analysis' technique. The practical lower limits for measurement of the phenoxy acid herbicides in water primarily depend upon the sample size, interferences present, anal instrumentation used. With l-liter samples of water, the practical lower limits of measurement are 10 ppt (parts per trillion) for 2,4-D and 2 ppt for silvex and 2,4,5-T when electron-capture detection is used, and approximately 20 ppt for each herbicide when analyzed by microcoulometric-titration gas chromatography. Recoveries of the herbicides immediately after addition to unfiltered water samples averaged 92 percent for 2,4-D, 90 percent for silvex, and 98 percent for 2

  5. Lake-Atmosphere Greenhouse Gas Exchange in Relation to Atmospheric Forcing and Water Clarity

    Science.gov (United States)

    Heiskanen, J. J.; Ojala, A.; Mammarella, I.; Vesala, T.

    2015-12-01

    Even though lakes cover only 2 % of the world's land surface, it has been estimated that lakes release about 10 % of the carbon fixed annually by the terrestrial ecosystems back to the atmosphere. A critical parameter in the gas exchange estimates is the gas transfer velocity (k), which is governed by turbulence. The aim of our study was to assess the current global CO2 evasion estimates from lakes to the atmosphere by comparing parameterizations for kand the significance of wind and heat flux to the gas transfer in small lakes. To improve future predictions of gas evasion from lakes, we focused on the changes in water clarity and how they affect water column physics and processes in the air-water interface. We studied a small boreal lake and used the eddy covariance (EC) method for the high precision data needed, and therefore also aimed to improve the EC methodology on lakes. The air-water gas transfer was related to both wind and heat loss during times of seasonal stratification, but only to wind during autumn overturn. When wind-induced thermocline tilting and resulting spatial variability in surface water CO2 concentrations was accounted for, average k derived from the measurements dropped from 6.0 cm h-1 to 5.2 cm h-1. This was still over twice the estimate (2.2 cm h-1) calculated with a widely used model for kin lakes suggesting that the global estimates of gas evasion from lakes might be underestimations. Water clarity was a significant parameter defining the thermal stratification of the lake: a change from clear to dark water would lead to shorter stratification period and lower water column temperatures in small lakes and therefore have significant impact on the lake-atmosphere exchange processes. Figure 1. The isotherms of Lake Kuivajärvi throughout the open-water period 2013. The top left are the measured temperatures and the others are modeled with LAKE model using fixed light extinction coefficient, Kd. The horizontal dashed black line represents

  6. Advances in interaction mechanism of water (gas) on clay minerals in China

    Institute of Scientific and Technical Information of China (English)

    He Manchao; Sun Xiaoming; Zhao Jian

    2014-01-01

    Dealing with large-scale deformations in soft-rock tunnels is a very important issue in soft-rock tunnel engineering. The mechanism of this large-scale deformation is closely related to the physical and chem-ical properties of soft rock, interaction between soft rock and water, and interaction between soft rock and gas contained in soft rock. In order to gain a better predictive understanding of the governing prin-ciples associated with this phenomenon, we used experimental and theoretical methods to study the effects of point defect on physical and chemical properties of soft rock and mechanism of interaction between water (gas) and soft rock. Firstly, we calculated the impurity formation energies and transition energy levels of defects by using the first-principle calculation, the results showed the microscopic mech-anism of defects substitution in kaolinite and effects of defects on the structure of kaolinite. Moreover, comparing the experimental and theoretical results, we found the mechanism of interaction between water and soft rock. The results show that water is one of the most important factors which can induce various kinds of geological disasters. At last, the interaction between soft rock and surrounding gas as CO2, CH4 and CO is disused, the influence of surrounding gas on soft rock should not be ignored.

  7. Pre-Gas Drilling Drinking Water Testing--An Educational Opportunity for Extension

    Science.gov (United States)

    Swistock, Brian; Clark, James

    2015-01-01

    The increase in shale gas drilling in Pennsylvania has resulted in thousands of landowners receiving predrilling testing of their drinking water. Landowners often have difficulty understanding test reports resulting in low awareness of pre-existing problems. Extension and several partners developed a program to improve understanding of…

  8. Size Effect of Silica Shell on Gas Uptake Kinetics in Dry Water.

    Science.gov (United States)

    Li, Yong; Zhang, Diwei; Bai, Dongsheng; Li, Shujing; Wang, Xinrui; Zhou, Wei

    2016-07-26

    Two kinds of dry water (DW) particles are prepared by mixing water and hydrophobic silica particles with nanometer or micrometer dimensions, and the two DW particles are found to have similar size distributions regardless of the size of the silica shell. The CO2 uptake kinetics of DW with nanometer (nanoshell) and micrometer shells (microshell) are measured, and both uptake rate and capacity show the obvious size effect of the silica shell. The DW with a microshell possesses a larger uptake capacity, whereas the DW with a nanoshell has a faster uptake rate. By comparing the uptake kinetics of soluble NH3 and CO2 further, we found that the microshell enhances the stability and the dispersion degree of DW and the nanoshell offers a shorter path for the transit of guest gas into the water core. Furthermore, molecular dynamics simulation is introduced to illustrate the nanosize effect of the silica shell on the initial step of the gas uptake. It is found that the concentration of gas molecules close to the silica shell is higher than that in the bulk water core. With the increase in the size of the silica shell, the amount of CO2 in the silica shell decreases, and it is easier for the gas uptake to reach steady state.

  9. Numerical studies on liquid water flooding in gas channels used inpolymer electrolyte fuel cells

    NARCIS (Netherlands)

    Qin, CZ.; Hassanizadeh, S.M.; Rensink, D.

    2012-01-01

    Water management plays an important role in the development of low-temperature polymer electrolyte fuel cells (PEFCs). The lack of a macroscopic gas channel (GC) flooding model constrains the current predictions of PEFC modeling under severe flooding situations. In this work, we have extended our pr

  10. Water droplet evaporation and dynamics in a mini-channel under action of the gas flow

    Science.gov (United States)

    Isachenko, E. A.; Orlik, E. V.; Bykovskaya, E. F.

    2016-10-01

    An experimental setup was developed to study the vaporization and dynamics of liquid droplets, blown by the gas flow in a mini-channel. The shadow method was the main method of measurement; a drop was also observed from the top. A series of experiments was carried out with single water drops with volumes varying from 60 to 150 gl in the channel of 6 mm height on the polished stainless steel substrate. The experiments have resulted in the dependences of evaporation rate in the temperature range of the substrate surface from 25 to 70°C and Reynolds numbers of the gas flow from 0 to 2500. The advancing and receding contact angles were measured depending on the Re number of the gas flow. The gas flow rate at which the droplet motion over the substrate starts was determined depending on the surface temperature at different drop volumes.

  11. High density gas state at water/graphite interface studied by molecular dynamics simulation

    Institute of Scientific and Technical Information of China (English)

    Wang Chun-Lei; Li Zhao-Xia; Li Jing-Yuan; Xiu Peng; Hu Jun; Fang Hai-Ping

    2008-01-01

    In this paper molecular dynamics simulations are performed to study the accumulation behaviour of N2 and H2 at water/graphite interface under ambient temperature and pressure. It finds that both N2 and H2 molecules can accumulate at the interface and form one of two states according to the ratio of gas molecules number to square of graphite surface from our simulation results: gas films (pancake-like) for a larger ratio and nanobubbles for a Smaller ratio. In addition, we discuss the stabilities of nanobubbles at different environment temperatures. Surprisingly, it is found that the density of both kinds of gas states can be greatly increased, even comparable with that of the liquid N2 and liquid H2. The present results are expected to be helpful for the understanding of the stable existence of gas film (pancake-like) and nanobubbles.

  12. Numerical Investigation of a Liquid-Gas Ejector Used for Shipping Ballast Water Treatment

    Directory of Open Access Journals (Sweden)

    Xueguan Song

    2014-01-01

    Full Text Available Shipping ballast water can have significant ecological and economic impacts on aquatic ecosystems. Currently, water ejectors are widely used in marine applications for ballast water treatment owing to their high suction capability and reliability. In this communication, an improved ballast treatment system employing a liquid-gas ejector is introduced to clear the ballast water to reduce environmental risks. Commonly, the liquid-gas ejector uses ballast water as the primary fluid and chemical ozone as the secondary fluid. In this study, high-pressure water and air, instead of ballast water and ozone, are considered through extensive numerical and experimental research. The ejector is particularly studied by a steady three-dimensional multiphase computational fluid dynamics (CFD analysis with commercial software ANSYS-CFX 14.5. Different turbulence models (including standard k-ε, RNG k-ε, SST, and k-ω with different grid size and bubble size are compared extensively and the experiments are carried out to validate the numerical design and optimization. This study concludes that the RNG k-ε turbulence model is the most efficient and effective for the ballast water treatment system under consideration and simple change of nozzle shape can greatly improve the ejector performance under high back pressure conditions.

  13. Evaluating Non-potable Water Usage for Oil and Gas Purposes in the Permian Basin

    Science.gov (United States)

    Marsac, K.; Pedrazas, M.; Suydam, S.; Navarre-Sitchler, A.

    2016-12-01

    Oil and gas company water usage is currently an area of extreme concern in the water stressed Western United States. 87% of the wells in Permian Basin are being drilled in areas of high or extreme water stress. Using recycled produced water or groundwater that does not meet the USDW drinking water standards for oil and gas purposes could assist in relieving both water stress and tension between oil and gas companies and the public. However, non-USDW drinking water (TDS over 10,000 ppm), has the potential to react with formation water causing mineral precipitation, reducing the permeability of the producing formation. To evaluate the potential of non-potable water usage in the Permian Basin, available groundwater chemistry data was compiled into a database. Data was collected from the NETL-run NATCARB database, the USGS Produced Water Database, and the Texas Railroad Commission. The created database went through a system of quality assurance and control for pH, TDS, depth and charge balance. Data was used to make a set of waters representative of Permian Basin groundwater based on TDS, Ca/Mg ratio and Cl/SO 4 ratio. Low, medium and high of these three characteristics; representing the 25 th , 50 th and 75 th percentile respectively; was used to make a matrix of 27 waters. Low TDS is 64,660 ppm, medium TDS is 98,486 ppm, and high TDS is 157,317 ppm. Ca/Mg ratios range from 1.98 to 7.26, and Cl/SO 4 ratios range from 32.96 to 62.34. Geochemical models of the mixing of these 27 waters with an average water were used to evaluate for possible precipitation. Initial results are positive, with the highest total precipitation being 2.371 cm 3 of dolomite and anhydrite in 2000 cm 3 of water with high TDS, high Ca/Mg ratio and low Cl/SO 4 ratio. This indicates a maximum of approximately 0.12% of porosity would be filled with mineral precipitation during the mixing of chosen Permian Basin waters.

  14. Quantitative calculation of GOR of complex oil-gas-water systems with logging data: A case study of the Yingdong Oil/Gas Field in the Qaidam Basin

    Directory of Open Access Journals (Sweden)

    Sima Liqiang

    2014-12-01

    Full Text Available In the Yingdong Oil/Gas Field of the Qaidam Basin, multiple suites of oil-gas-water systems overlie each other vertically, making it difficult to accurately identify oil layers from gas layers and calculate gas-oil ratio (GOR. Therefore, formation testing and production data, together with conventional logging, NMR and mud logging data were integrated to quantitatively calculate GOR. To tell oil layers from gas layers, conventional logging makes use of the excavation effect of compensated neutron log, NMR makes use of the different relaxation mechanisms of light oil and natural gas in large pores, while mud logging makes use of star chart of gas components established based on available charts and mathematical statistics. In terms of the quantitative calculation of GOR, the area ratio of the star chart of gas components was first used in GOR calculation. The study shows that: (1 conventional logging data has a modest performance in distinguishing oil layers from gas layers due to the impacts of formation pressure, hydrogen index (HI, shale content, borehole conditions and invasion of drilling mud; (2 NMR is quite effective in telling oil layers from gas layers, but cannot be widely used due to its high cost; (3 by contrast, the star chart of gas components is the most effective in differentiating oil layers from gas layers; and (4 the GOR calculated by using the area ratio of star chart has been verified by various data such as formation testing data, production data and liquid production profile.

  15. Impacts of Urban Water Conservation Strategies on Energy, Greenhouse Gas Emissions, and Health: Southern California as a Case Study.

    Science.gov (United States)

    Sokolow, Sharona; Godwin, Hilary; Cole, Brian L

    2016-05-01

    To determine how urban water conservation strategies in California cities can affect water and energy conservation efforts, reduce greenhouse gas emissions, and benefit public health. We expanded upon our 2014 health impact assessment of California's urban water conservation strategies by comparing the status quo to 2 options with the greatest potential impact on the interrelated issues of water and energy in California: (1) banning landscape irrigation and (2) expanding alternative water sources (e.g., desalination, recycled water). Among the water conservation strategies evaluated, expanded use of recycled water stood out as the water conservation strategy with potential to reduce water use, energy use, and greenhouse gas emissions, with relatively small negative impacts for the public's health. Although the suitability of recycled water for urban uses depends on local climate, geography, current infrastructure, and finances, analyses similar to that presented here can help guide water policy decisions in cities across the globe facing challenges of supplying clean, sustainable water to urban populations.

  16. Increasing gas output by an active water-pressure regime interaction in a massive deposit at the Korobsk field

    Energy Technology Data Exchange (ETDEWEB)

    Trubaev, V.L.; Shandrygin, A.N.

    1983-02-01

    Controlled water flooding and pressurization were used to increase the gas output at the Korobsk field (USSR). The mechanics of gas accumulation under flooding conditions depend on the macroheterogeneity of the collector; optimizing the gas output involves selective flooding and pressurizing the water to prevent gas pocket formation in the zones bypassed by the flooded front. Strata mapping of the Korobsk field, combined with theoretical and laboratory studies of the geological characteristics of the deposit, has made it possible to estimate the location and distribution of the various types of residual gas pockets.

  17. A Statistical Framework for Automatic Leakage Detection in Smart Water and Gas Grids

    Directory of Open Access Journals (Sweden)

    Marco Fagiani

    2016-08-01

    Full Text Available In the last few years, due to the technological improvement of advanced metering infrastructures, water and natural gas grids can be regarded as smart-grids, similarly to power ones. However, considering the number of studies related to the application of computational intelligence to distribution grids, the gap between power grids and water/gas grids is notably wide. For this purpose, in this paper, a framework for leakage identification is presented. The framework is composed of three sections aimed at the extraction and the selection of features and at the detection of leakages. A variation of the Sequential Feature Selection (SFS algorithm is used to select the best performing features within a set, including, also, innovative temporal ones. The leakage identification is based on novelty detection and exploits the characterization of a normality model. Three statistical approaches, The Gaussian Mixture Model (GMM, Hidden Markov Model (HMM and One-Class Support Vector Machine (OC-SVM, are adopted, under a comparative perspective. Both residential and office building environments are investigated by means of two datasets. One is the Almanac of Minutely Power dataset (AMPds, and it provides water and gas data consumption at 1, 10 and 30 min of time resolution; the other is the Department of International Development (DFID dataset, and it provides water and gas data consumption at 30 min of time resolution. The achieved performance, computed by means of the Area Under the Curve (AUC, reaches 90 % in the office building case study, thus confirming the suitability of the proposed approach for applications in smart water and gas grids.

  18. Unconventional Oil and Gas Resources in Texas and Other Mining Activities: the Water Challenge

    Science.gov (United States)

    Nicot, J.

    2011-12-01

    A recent study, sponsored by the Texas Water Development Board, considered current and projected water use in the mining industry. It looked at the upstream segment of the oil and gas industry (that is, water used to extract the commodity until it leaves the wellhead), the aggregate, and coal industry, and other substances (industrial sand, lime, etc.). We obtained data through state databases, data collection from private vendors, and direct surveys of the various sectors of the industry. Overall, in 2008, we estimated that the state consumed ~160 thousand acre-feet (AF) in the mining industry, including 35.8 thousand AF for fracing wells (mostly in the Barnett Shale/Fort Worth area) and ~21.0 thousand AF for other purposes in the oil and gas industry, although more spread out across the state, with a higher demand in the Permian Basin area in West Texas. The coal industry used 20.0 thousand AF along the lignite belt from Central to East Texas. The 71.6 thousand AF used by the aggregate industry is distributed over most of the state, but with a clear concentration around major metropolitan areas. The remainder amounts to 11.0 thousand AF and is dominated by industrial sand production (~80% of total). Water is used mostly for drilling wells, stimulating/fracing wells, and secondary and tertiary recovery processes (oil and gas industry); for dewatering and depressurizing pits, with a small amount used for dust control (coal industry); and for dust control and washing (aggregate industry and industrial sand). Reuse/recycling has already been accounted for in water-use values, as well as opportunity usages, such as stormwater collection (aggregates). The split between surface water and groundwater is difficult to assess but it is estimated at ~56% groundwater in 2008. Projections for future use were done by extrapolating current trends, mainly for coal (same energy mix) and aggregates (following population growth). Projections for the oil and gas industry (Barnett

  19. Peach water relations, gas exchange, growth and shoot mortality under water deficit in semi-arid weather conditions.

    Directory of Open Access Journals (Sweden)

    Mitra Rahmati

    Full Text Available In this study the sensitivity of peach tree (Prunus persica L. to three water stress levels from mid-pit hardening until harvest was assessed. Seasonal patterns of shoot and fruit growth, gas exchange (leaf photosynthesis, stomatal conductance and transpiration as well as carbon (C storage/mobilization were evaluated in relation to plant water status. A simple C balance model was also developed to investigate sink-source relationship in relation to plant water status at the tree level. The C source was estimated through the leaf area dynamics and leaf photosynthesis rate along the season. The C sink was estimated for maintenance respiration and growth of shoots and fruits. Water stress significantly reduced gas exchange, and fruit, and shoot growth, but increased fruit dry matter concentration. Growth was more affected by water deficit than photosynthesis, and shoot growth was more sensitive to water deficit than fruit growth. Reduction of shoot growth was associated with a decrease of shoot elongation, emergence, and high shoot mortality. Water scarcity affected tree C assimilation due to two interacting factors: (i reduction in leaf photosynthesis (-23% and -50% under moderate (MS and severe (SS water stress compared to low (LS stress during growth season and (ii reduction in total leaf area (-57% and -79% under MS and SS compared to LS at harvest. Our field data analysis suggested a Ψstem threshold of -1.5 MPa below which daily net C gain became negative, i.e. C assimilation became lower than C needed for respiration and growth. Negative C balance under MS and SS associated with decline of trunk carbohydrate reserves--may have led to drought-induced vegetative mortality.

  20. Peach water relations, gas exchange, growth and shoot mortality under water deficit in semi-arid weather conditions.

    Science.gov (United States)

    Rahmati, Mitra; Davarynejad, Gholam Hossein; Génard, Michel; Bannayan, Mohammad; Azizi, Majid; Vercambre, Gilles

    2015-01-01

    In this study the sensitivity of peach tree (Prunus persica L.) to three water stress levels from mid-pit hardening until harvest was assessed. Seasonal patterns of shoot and fruit growth, gas exchange (leaf photosynthesis, stomatal conductance and transpiration) as well as carbon (C) storage/mobilization were evaluated in relation to plant water status. A simple C balance model was also developed to investigate sink-source relationship in relation to plant water status at the tree level. The C source was estimated through the leaf area dynamics and leaf photosynthesis rate along the season. The C sink was estimated for maintenance respiration and growth of shoots and fruits. Water stress significantly reduced gas exchange, and fruit, and shoot growth, but increased fruit dry matter concentration. Growth was more affected by water deficit than photosynthesis, and shoot growth was more sensitive to water deficit than fruit growth. Reduction of shoot growth was associated with a decrease of shoot elongation, emergence, and high shoot mortality. Water scarcity affected tree C assimilation due to two interacting factors: (i) reduction in leaf photosynthesis (-23% and -50% under moderate (MS) and severe (SS) water stress compared to low (LS) stress during growth season) and (ii) reduction in total leaf area (-57% and -79% under MS and SS compared to LS at harvest). Our field data analysis suggested a Ψstem threshold of -1.5 MPa below which daily net C gain became negative, i.e. C assimilation became lower than C needed for respiration and growth. Negative C balance under MS and SS associated with decline of trunk carbohydrate reserves--may have led to drought-induced vegetative mortality.

  1. Isotopic, chemical and dissolved gas constraints on spring water from Popocatepetl volcano (Mexico): evidence of gas water interaction between magmatic component and shallow fluids

    Science.gov (United States)

    Inguaggiato, S.; Martin-Del Pozzo, A. L.; Aguayo, A.; Capasso, G.; Favara, R.

    2005-03-01

    Geochemical research was carried out on cold and hot springs at Popocatepetl (Popo) volcano (Mexico) in 1999 to identify a possible relationship with magmatic activity. The chemical and isotopic composition of the fluids is compatible with strong gas-water interaction between deep and shallow fluids. In fact, the isotopic composition of He and dissolved carbon species is consistent with a magmatic origin. The presence of a geothermal system having a temperature of 80-100° C was estimated on the basis of liquid geothermometers. A large amount of dissolved CO 2 in the springs was also detected and associated with high CO 2 degassing.

  2. Theoretical insight into the conversion of xylose to furfural in the gas phase and water.

    Science.gov (United States)

    Wang, Meng; Liu, Chao; Li, Qibin; Xu, Xiaoxiao

    2015-11-01

    Furfural (FF) is a valuable ring-containing organic compound in the decomposition of xylose and can be produced massively in hydrothermal condition. In this study, density functional theory (DFT) methods are employed to investigate the formation mechanism of FF from xylose and the solvent effects on FF formation. Kinetic and thermodynamic analyses indicate that xylulose could be the intermediate that leads to the formation of FF in the gas phase and water. The formation of xylulose is initiated by a six-membered transition state with energy barriers of 163.6 and 150.8 kJ mol(-1) in the gas phase and water, respectively. It is found that the strong stabilization of the reactants and transition states and the overall energy barriers of formation pathways of FF are reduced in water. The formation of FF is more thermodynamically favored in water compared with that in the gas phase. In addition, the inclusion of an explicit water molecule transforms four-membered transition states of ring-opening reaction, hydrogenation-cyclization, and dehydrations into less distorted six-membered transition states, which leads to the significant reduction of reaction barriers of FF formation.

  3. Gravimetric monitoring of water influx into a gas reservoir: A numerical study based on the ensemble kalman filter

    NARCIS (Netherlands)

    Glegola, M.; Ditmar, P.; Hanea, R.G.; Vossepoel, F.C.; Arts, R.; Klees, R.

    2012-01-01

    Water influx into gas fields can reduce recovery factors by 10-40%. Therefore, information about the magnitude and spatial distribution of water influx is essential for efficient management of waterdrive gas reservoirs. Modern geophysical techniques such as gravimetry may provide a direct measure of

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

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, S.A.

    1988-01-01

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

  5. [Effects of soil water status on gas exchange of peanut and early rice leaves].

    Science.gov (United States)

    Chen, Jiazhou; Lü, Guoan; He, Yuanqiu

    2005-01-01

    The gas exchange characteristics of peanut and early rice leaves were investigated in experimental plots under different soil water conditions over a long growth period. The results showed that at the branching stage of peanut, the stomatal conductance (Gs) and transpiration rate (Tr) decreased slightly under mild and moderate soil water stress, while the net photosynthetic rate (Pn) and leaf water use efficiency (WUE) increased. The Gs/Tr ratio also increased under mild water stress, but decreased under moderate water stress. At podding stage, the Gs, Tr, Gs/Tr ratio and Pn decreased, while WUE increased significantly under mild and moderate water stress. The peanut was suffered from water stress at its pod setting stage. At the grain filling stage of early rice, the Gs, Tr and Gs/Tr ratio fluctuated insignificantly under mild and moderate water stress, while Pn and WUE increased significantly, with an increase in grain yield under mild water stress. It's suggested that the combination of Gs and Gs/Tr ratio could be a reference index for crop water stress, namely, crops could be hazarded by water stress when Gs and Gs/Tr decreased synchronously.

  6. Water maser emission from X-ray-heated circumnuclear gas in active galaxies

    Science.gov (United States)

    Neufeld, David A.; Maloney, Philip R.; Conger, Sarah

    1994-01-01

    We have modeled the physical and chemical conditions present within dense circumnuclear gas that is irradiated by X-rays from an active galactic nucleus. Over a wide range of X-ray fluxes and gas pressures, the effects of X-ray heating give rise to a molecular layer at temperatures of 400-1000 K within which the water abundance is large. The physical conditions within this molecular layer naturally give rise to collisionally pumped maser emission in the 6(sub 16) - 5(sub 23) 22 GHz transition of ortho-water, with predicted maser luminosities of 10(exp 2 +/- 0.5) solar luminosity per sq. pc of illuminated area. Given plausible assumptions about the geometry of the source and about the degree to which the maser emission is anisotropic, such surface luminosities are sufficient to explain the large apparent luminosities observed in water maser sources that are associated with active galactic nuclei.

  7. Preliminary Modeling, Testing, and Analysis of a Gas Tankless Water Heater: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Hoeschele, M.; Springer, D.; Rudd, A.

    2008-05-01

    Today's gas tankless water heaters offer significant energy savings over conventional gas storage tank water heaters, but savings depends on the draw pattern. A one-node model incorporating heat exchanger mass is used to address this and other issues. Key model parameters are determined from least-squares regression on short-term data, including burner efficiency, thermal capacitance, and thermal loss coefficient. The calibrated model agrees with data to ~5% on Qgas, with temperature RMS deviation of ~4..deg..C. Efficiency with a standard realistic draw is 71%, compared to 81% predicted from standard energy-factors. Adding a small tank controlled by the tankless heater solves issues of oscillations with solar pre-heat, low-flow and hot-water-delay issues. Future work includes model refinements and developing optimal data protocols for model parameter extraction.

  8. Molecular conformation of linear alkane molecules: From gas phase to bulk water through the interface

    Science.gov (United States)

    Murina, Ezequiel L.; Fernández-Prini, Roberto; Pastorino, Claudio

    2017-08-01

    We studied the behavior of long chain alkanes (LCAs) as they were transferred from gas to bulk water, through the liquid-vapor interface. These systems were studied using umbrella sampling molecular dynamics simulation and we have calculated properties like free energy profiles, molecular orientation, and radius of gyration of the LCA molecules. The results show changes in conformation of the solutes along the path. LCAs adopt pronounced molecular orientations and the larger ones extend appreciably when partially immersed in the interface. In bulk water, their conformations up to dodecane are mainly extended. However, larger alkanes like eicosane present a more stable collapsed conformation as they approach bulk water. We have characterized the more probable configurations in all interface and bulk regions. The results obtained are of interest for the study of biomatter processes requiring the transfer of hydrophobic matter, especially chain-like molecules like LCAs, from gas to bulk aqueous systems through the interface.

  9. Water maser emission from X-ray-heated circumnuclear gas in active galaxies

    Science.gov (United States)

    Neufeld, David A.; Maloney, Philip R.; Conger, Sarah

    1994-12-01

    We have modeled the physical and chemical conditions present within dense circumnuclear gas that is irradiated by X-rays from an active galactic nucleus. Over a wide range of X-ray fluxes and gas pressures, the effects of X-ray heating give rise to a molecular layer at temperatures of 400-1000 K within which the water abundance is large. The physical conditions within this molecular layer naturally give rise to collisionally pumped maser emission in the 616 - 523 22 GHz transition of ortho-water, with predicted maser luminosities of 102 +/- 0.5 solar luminosity per sq. pc of illuminated area. Given plausible assumptions about the geometry of the source and about the degree to which the maser emission is anisotropic, such surface luminosities are sufficient to explain the large apparent luminosities observed in water maser sources that are associated with active galactic nuclei.

  10. ANALYSIS OF PENTACHLOROPHENOL IN WATER BY PURGE AND TRAP CONCENTRATOR COUPLED TO GAS CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    HuixiaLan; YuancaiChen; ZhonghaoChen

    2004-01-01

    It is convenient and time saving to analyze pentachlorophenol (PCP) in water by purge and trap concentrator coupled to gas chromatography that avoids employing a great deal of organic solvent. In this paper, the appropriate purge and trap conditions of PCP are determined: the trapped sorbent is TenaxGC; the purge gas is pure nitrogen and purge flow is 40ml/min; the purge time is 30min. A series of standard PCP water samples 5, 10, 50, 100, 200, 400, 800, 1000ppb are analyzed in order to obtain standard curve, and the linear regressive equation obtained is Y=109.65X-687.72, which correlation coefficient r is 0.9949. The precision of the method is determined with 0.5ppb PCP water sample, and the standard deviation measured is 3%. The detection limit for PCP is 0.2ppb.

  11. Molecular Density Functional Theory for water with liquid-gas coexistence and correct pressure

    CERN Document Server

    Jeanmairet, Guillaume; Sergiievskyi, Volodymyr; Borgis, Daniel

    2015-01-01

    The solvation of hydrophobic solutes in water is special because liquid and gas are almost at coexistence. In the common hypernetted chain approximation to integral equations, or equivalently in the homogenous reference fluid of molecular density functional theory, coexistence is not taken into account. Hydration structures and energies of nanometer-scale hydrophobic solutes are thus incorrect. In this article, we propose a bridge functional that corrects this thermodynamic inconsistency by introducing a metastable gas phase for the homogeneous solvent. We show how this can be done by a third order expansion of the functional around the bulk liquid density that imposes the right pressure and the correct second order derivatives. Although this theory is not limited to water, we apply it to study hydrophobic solvation in water at room temperature and pressure and compare the results to all-atom simulations. With this correction, molecular density functional theory gives, at a modest computational cost, quantita...

  12. Surface velocity divergence model of air/water interfacial gas transfer in open-channel flows

    Science.gov (United States)

    Sanjou, M.; Nezu, I.; Okamoto, T.

    2017-04-01

    Air/water interfacial gas transfer through a free surface plays a significant role in preserving and restoring water quality in creeks and rivers. However, direct measurements of the gas transfer velocity and reaeration coefficient are still difficult, and therefore a reliable prediction model needs to be developed. Varying systematically the bulk-mean velocity and water depth, laboratory flume experiments were conducted and we measured surface velocities and dissolved oxygen (DO) concentrations in open-channel flows to reveal the relationship between DO transfer velocity and surface divergence (SD). Horizontal particle image velocimetry measurements provide the time-variations of surface velocity divergence. Positive and negative regions of surface velocity divergence are transferred downstream in time, as occurs in boil phenomenon on natural river free-surfaces. The result implies that interfacial gas transfer is related to bottom-situated turbulence motion and vertical mass transfer. The original SD model focuses mainly on small-scale viscous motion, and this model strongly depends on the water depth. Therefore, we modify the SD model theoretically to accommodate the effects of the water depth on gas transfer, introducing a non-dimensional parameter that includes contributions of depth-scale large-vortex motion, such as secondary currents, to surface renewal events related to DO transport. The modified SD model proved effective and reasonable without any dependence on the bulk mean velocity and water depth, and has a larger coefficient of determination than the original SD model. Furthermore, modeling of friction velocity with the Reynolds number improves the practicality of a new formula that is expected to be used in studies of natural rivers.

  13. Strategies to diagnose and control microbial souring in natural gas storage reservoirs and produced water systems

    Energy Technology Data Exchange (ETDEWEB)

    Morris, E.A.; Derr, R.M.; Pope, D.H.

    1995-12-31

    Hydrogen sulfide production (souring) in natural gas storage reservoirs and produced water systems is a safety and environmental problem that can lead to operational shutdown when local hydrogen sulfide standards are exceeded. Systems affected by microbial souring have historically been treated using biocides that target the general microbial community. However, requirements for more environmentally friendly solutions have led to treatment strategies in which sulfide production can be controlled with minimal impact to the system and environment. Some of these strategies are based on microbial and/or nutritional augmentation of the sour environment. Through research sponsored by the Gas Research Institute (GRI) in Chicago, Illinois, methods have been developed for early detection of microbial souring in natural gas storage reservoirs, and a variety of mitigation strategies have been evaluated. The effectiveness of traditional biocide treatment in gas storage reservoirs was shown to depend heavily on the methods by which the chemical is applied. An innovative strategy using nitrate was tested and proved ideal for produced water and wastewater systems. Another strategy using elemental iodine was effective for sulfide control in evaporation ponds and is currently being tested in microbially sour natural gas storage wells.

  14. Comprehensive Review of Foam Application during Foam Assisted Water Alternating Gas (FAWAG Method

    Directory of Open Access Journals (Sweden)

    A. Shabib-asl

    2014-11-01

    Full Text Available In the last few decades, much focus has been placed on enhancing oil recovery from existing fields. This is accomplished by the study and application of various methods. As for recent cases, the Study of fluid mobility control and sweep efficiency in gas injection process as well as Water Alternating Gas (WAG method have demonstrated positive results on oil recovery and thus gained wide interest in petroleum industry. WAG injection application results in an increased oil recovery. Its mechanism consists in reduction of Gas Oil Ratio (GOR. However, there are some problems associated with this which includes poor volumetric sweep efficiency due to its low density and high mobility when compared with oil. This has led to the introduction of Foam Assisted Water Alternating Gas (FAWAG technique, which in contrast with WAG injection, acts in improving the sweep efficiency and reducing the gas oil ration therefore maximizing the production rate from the producer wells. This study presents a comprehensive review of FAWAG process from perspective of Snorre field experience. In addition some comparative results between FAWAG and the other EOR methods are presented including their setbacks. The main aim is to provide a solid background for future laboratory research and successful field application-extend.

  15. Polymer Growth Rate in a Wire Chamber with Oxygen,Water, or Alcohol Gas Additives

    Energy Technology Data Exchange (ETDEWEB)

    Boyarski, Adam; /SLAC

    2008-07-02

    The rate of polymer growth on wires was measured in a wire chamber while the chamber was aged initially with helium-isobutane (80:20) gas, and then with either oxygen, water, or alcohol added to the gas. At the completion of the aging process for each gas mixture, the carbon content on the wires was measured in a SEM/EDX instrument. The same physical wires were used in all the gas mixtures, allowing measurement of polymer build up or polymer depletion by each gas additive. It is found that the rate of polymer growth is not changed by the presence of oxygen, water or alcohol. Conjecture that oxygen reduces breakdown by removing polymer deposits on field wires is negated by these measurements. Instead, it appears that the reduced breakdown is due to lower resistance in the polymer from oxygen ions being transported into the polymer. It is also observed that field wires bombarded by the electrons in the SEM and then placed back into the chamber show an abundance of single electrons being emitted, indicating that electron charge is stored in the polymer layer and that a high electric field is necessary to remove the charge.

  16. Process for desalting and dehydration of crude oil including hot water washing and gas stripping

    Energy Technology Data Exchange (ETDEWEB)

    Popp, V.V.; Suditu, I.; Neagu, P.; Fotescu, L.; Mihalache, I.; Tirboiu, D.

    1979-12-25

    Process and apparatus for the desalting and dehydration of crude oil is described, in which the crude oil is washed in one or several stages using fresh or recirculated hot water containing a demulsifier. The crude oil is also passed through a coalescence stage, and a settling stage aimed at obtaining a salt content to meet crude oil specifications. Subsequently the crude oil is led into a lower stripping compartment of a column, in which dehydration is carried out to the desired level by using fuel or combustion gas. The stripping temperature is reached by heating the crude or the gas or both. The gas-vapor mixture is cooled in the upper compartment of the column by a cooling fluid such as the untreated crude oil or recirculated or fresh water, depending upon the nature and salt content of the crude. The cooled gas is recirculated within the column or led to a pipeline for consumption, while the cooling fluid, in the case of water, is recirculated in the unit.

  17. Kinetic and Phase Behaviors of Catalytic Cracking Dry Gas Hydrate in Water-in-Oil Emulsion

    Institute of Scientific and Technical Information of China (English)

    MA Qinglan; HUANG Qiang; CHEN Guangjin; WANG Xiulin; SUN Changyu; YANG Lanying

    2013-01-01

    The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion.The effect of temperature,pressure and initial gas-liquid ratio on the hydrate formation was studied,respectively.The data were obtained at pressures ranging from 3.5 to 5 MPa and temperatures from 274.15 to 277.15 K.The results showed that hydrogen and methane can be separated from the C2+ fraction by forming hydrate at around 273.15 K which is much higher temperature than that of the cryogenic separation method,and the hydrate formation rate can be enhanced in the water-in-oil emulsion compared to pure water.The experiments provided the basic data for designing the industrial process,and setting the suitable operational conditions.The measured data of gas-hydrate equilibria were compared with the predictions by using the Chen-Guo hydrate thermodynamic model.

  18. Hydrate film growth on the surface of a gas bubble suspended in water.

    Science.gov (United States)

    Peng, B Z; Dandekar, A; Sun, C Y; Luo, H; Ma, Q L; Pang, W X; Chen, G J

    2007-11-01

    The lateral film growth rate of CH4, C2H4, CO2, CH4 + C2H4, and CH4 + C3H8 hydrates in pure water were measured at four fixed temperatures of 273.4, 275.4, 277.4, and 279.4 K by means of suspending a single gas bubble in water. The results showed that the lateral growth rates of mixed-gas CH4 + C2H4 hydrate films were slower than that of pure gas (CH4 or C2H4) for the same driving force and that of mixed-gas CH4 + C3H8 hydrate film growth was the slowest. The dependence of the thickness of hydrate film on the driving force was investigated, and it was demonstrated that the thickness of hydrate film was inversely proportional to the driving force. It was found that the convective heat transfer control model reported in the literature could be used to formulate the lateral film growth rate v(f) with the driving force DeltaT perfectly for all systems after introduction of the assumption that the thickness of hydrate films is inversely proportional to the driving force DeltaT; i.e., v(f) = psiDeltaT(5/2) is correct and independent of the composition of gas and the type of hydrate. The thicknesses of different gas hydrate films were estimated, and it is demonstrated that the thicknesses of mixed-gas hydrate films were thicker than those of pure gases, which was qualitatively consistent with the experimental result.

  19. Recovery of Fresh Water Resources from Desalination of Brine Produced During Oil and Gas Production Operations

    Energy Technology Data Exchange (ETDEWEB)

    David B. Burnett; Mustafa Siddiqui

    2006-12-29

    Management and disposal of produced water is one of the most important problems associated with oil and gas (O&G) production. O&G production operations generate large volumes of brine water along with the petroleum resource. Currently, produced water is treated as a waste and is not available for any beneficial purposes for the communities where oil and gas is produced. Produced water contains different contaminants that must be removed before it can be used for any beneficial surface applications. Arid areas like west Texas produce large amount of oil, but, at the same time, have a shortage of potable water. A multidisciplinary team headed by researchers from Texas A&M University has spent more than six years is developing advanced membrane filtration processes for treating oil field produced brines The government-industry cooperative joint venture has been managed by the Global Petroleum Research Institute (GPRI). The goal of the project has been to demonstrate that treatment of oil field waste water for re-use will reduce water handling costs by 50% or greater. Our work has included (1) integrating advanced materials into existing prototype units and (2) operating short and long-term field testing with full size process trains. Testing at A&M has allowed us to upgrade our existing units with improved pre-treatment oil removal techniques and new oil tolerant RO membranes. We have also been able to perform extended testing in 'field laboratories' to gather much needed extended run time data on filter salt rejection efficiency and plugging characteristics of the process train. The Program Report describes work to evaluate the technical and economical feasibility of treating produced water with a combination of different separation processes to obtain water of agricultural water quality standards. Experiments were done for the pretreatment of produced water using a new liquid-liquid centrifuge, organoclay and microfiltration and ultrafiltration membranes

  20. Ab initio study of gas phase and water-assisted tautomerization of maleimide and formamide

    Indian Academy of Sciences (India)

    Susheel Kalia; Anju Sharma; B S Kaith

    2007-11-01

    Maleimide serves as an important starting material in the synthesis of drugs and enzyme inhibitors. In the present paper, knowing the importance of tautomerization in maleimide for its drug action, potential energy surface of maleimide is studied and its tautomerization has been discussed and compared with tautomerization of formamide. Gas phase tautomerization of maleimide requires large amount of energy (23.21 kcal/mol) in comparison to formamide (15.05 kcal/mol) at HF/6-31+G* level. Thus making the proton transfer reaction a difficult process in gas phase. Water molecule lowers the energy barrier of tautomerization thus facilitating the tautomerization of maleimide to 5-hydroxy-pyrrol-2-one. Water assisted tautomerization of maleimide requires 19.60 kcal/mol energy at HF/6-31+G* and 17.63 kcal/mol energy at B3LYP/6-31+G* level, a decrease of 3.61 and 5.96 kcal/mol over gas phase tautomerization. Whereas, tautomerization of formamide requires 14.16 and 12.84 kcal/mol energy, a decrease of 0.89 and 2.01 kcal/mol energy over gas phase tautomerization at HF/6-31+G* and B3LYP/6-31+G* level, respectively. Water-assisted tautomerization in maleimide and formamide showed that difference in energy barrier reduces to 2.83 kcal/mol from 10.41 kcal/mol (in gas phase) at B3LYP level, which resulted that maleimide readily undergoes tautomerization in water molecule.

  1. Electron attachment to oxygen, water, and methanol, in various drift chamber gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Huk, M.; Igo-Kemenes, P.; Wagner, A.

    1988-04-15

    Attachment of electrons to oxygen, water, and methanol molecules has been studied in various gas mixtures based on argon, methane and isobutane, a class of gases often used to operate large drift chambers. The measurements were performed using a drift chamber in which the conditions prevailing in large experiments could be closely reproduced. Attachment coefficients were extracted as a function of the gas composition and pressure, the drift field, and the concentration of the molecules under investigation. The observed effects are compared to other measurements, and are discussed within the frame of physical models. (orig.)

  2. Electron attachment to oxygen, water, and methanol, in various drift chamber gas mixtures

    Science.gov (United States)

    Huk, M.; Igo-Kemenes, P.; Wagner, A.

    1988-04-01

    Attachment of electrons to oxygen, water, and methanol molecules has been studied in various gas mixtures based on argon, methane and isobutane, a class of gases often used to operate large drift chambers. The measurements were performed using a drift chamber in which the conditions prevailing in large experiments could be closely reproduced. Attachment coefficients were extracted as a function of the gas composition and pressure, the drift field, and the concentration of the molecules under investigation. The observed effects are compared to other measurements, and are discussed within the frame of physical models.

  3. Water retention, gas transport, and pore network complexity during short-term regeneration of soil structure

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Møldrup, Per; Schjønning, Per

    2013-01-01

    was done using water retention (pore size distribution), soil gas diffusivity, air permeability, and derived pore network complexity parameters. Significant decreases in bulk density (increased total porosity) and increases in pores > 100 1m was observed for incubated samples compared with SR samples....... The proportion of pores > 100 1m increased in order: smectite gas diffusivity, air permeability, and derived pore network indices was greater for incubated samples than SR. For illitic soils...... for convective air transport when analyzing pore network complexity. Overall, our results showed that short-term regeneration...

  4. New test for oil soluble/water dispersible gas pipeline inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Stegmann, D.W.; Asperger, R.G.

    1987-01-01

    The wheel test provides good mixing of the condensate and water phases, the coupons are exposed to both phases. Therefore, the wheel test cannot distinguish between inhibitors that need continuous mixing of the these phases to maintain a water dispersion of the inhibitor and inhibitors that will self disperse into the water. This concept becomes important for pipelines in stratified flow where the water can settle out. In these cases with low turbulence, the inhibitor must self disperse into the water to be effective. The paper describes a test method to measure the effectiveness of an inhibitor and its ability to self disperse. The effectiveness of several inhibitors as predicted by the new test method is discussed relative to data from the wheel test and breaker tests. Field performance of these inhibitors in a gas gathering line, with liquids in stratified flow, are cities and compared with the results of the various laboratory tests.

  5. Role of dissolved gas in optical breakdown of water: differences between effects due to helium and other gases.

    Science.gov (United States)

    Bunkin, N F; Ninham, B W; Babenko, V A; Suyazov, N V; Sychev, A A

    2010-06-17

    It is shown that water contains defects in the form of heterogeneous optical breakdown centers. Long-living complexes composed of gas and liquid molecules may serve as nuclei for such centers. A new technique for removing dissolved gas from water is developed. It is based on a "helium washing" routine. The structure of helium-washed water is very different from that of water containing dissolved atmospheric gas. It is able to withstand higher optical intensities and temperatures of superheating compared with the nonprocessed ones. The characteristics of plasma spark and values of the breakdown thresholds for processed and nonprocessed samples are given.

  6. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    Science.gov (United States)

    Post, David

    2016-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. Surface water and groundwater modelling is now complete for two regions where coal seam gas development may proceed, namely the Clarence-Moreton and Gloucester regions in eastern New South Wales. This presentation will discuss how the results of these

  7. Obliquity-Controlled Water Vapor/Trace Gas Feedback in the Martian Greenhouse Cycle

    Science.gov (United States)

    Mischna, M. A.; Baker, V. R.; Milliken, R.; Richardson, M. I.; Lee, C.

    2013-12-01

    We have explored possible mechanisms for the generation of warm, wet climates on early Mars as a result of greenhouse warming by both water vapor and periodic volcanic trace gas emissions, using the Mars Weather Research and Forecasting (MarsWRF) general circulation model. The presence of both water vapor (a strong greenhouse gas) and other trace greenhouse gases (such as SO2) in a predominantly CO2 atmosphere may act, under certain conditions, to elevate surface temperatures above the freezing point of liquid water, at least episodically. The levels of warming obtained in our simulations do not reach the values seen in Johnson et al., (2008, JGR, 113, E08005), nor are they widespread for extended periods. Rather, warming above 273 K is found in more localized environments and for geologically brief periods of time. Such periodic episodes are controlled by two factors. First is the obliquity of the planet, which plays a significant role is ';activating' extant surface water ice reservoirs, allowing levels of atmospheric water vapor to rise when obliquity is high, and fall precipitously when the obliquity is low. During these low-obliquity periods, the atmosphere is all but incapable of supporting warm surface temperatures except for brief episodes localized wholly in the tropics; thus, there is a natural regulator in the obliquity cycle for maintaining periodic warming. Second is the presence of a secondary trace gas 'trigger', like volcanically released SO2, in the atmosphere. In the absence of such a trace gas, water vapor alone appears incapable of raising temperatures above the melting point; however, by temporarily raising the baseline global temperatures (in the absence of warming by water vapor) by 10-15 K, as with SO2, the trigger gas keeps atmospheric temperatures sufficiently warm, especially during nighttime, to maintain levels of water vapor in the atmosphere that provide the needed warming. Furthermore, we find that global warming can be achieved more

  8. The simulation of gas production from oceanic gas hydrate reservoir by the combination of ocean surface warm water flooding with depressurization

    Institute of Scientific and Technical Information of China (English)

    Hao Yang; Yu-Hu Bai; Qing-Ping Li

    2012-01-01

    A new method is proposed to produce gas from oceanic gas hydrate reservoir by combining the ocean surface warm water flooding with depressurization which can efficiently utilize the synthetic effects of thermal,salt and depressurization on gas hydrate dissociation.The method has the advantage of high efficiency,low cost and enhanced safety.Based on the proposed conceptual method,the physical and mathematical models are established,in which the effects of the flow of multiphase fluid,the kinetic process of hydrate dissociation,the endothermic process of hydrate dissociation,ice-water phase equilibrium,salt inhibition,dispersion,convection and conduction on the hydrate dissociation and gas and water production are considered.The gas and water rates,formation pressure for the combination method are compared with that of the single depressurization,which is referred to the method in which only depressurization is used.The results show that the combination method can remedy the deficiency of individual producing methods.It has the advantage of longer stable period of high gas rate than the single depressurization.It can also reduce the geologic hazard caused by the formation deformation due to the maintaining of the formation pressure by injected ocean warm water.

  9. PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol Steam Reforming, and Reverse-Water-Gas-Shift

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A.; Platon, Alexandru; Datye, Abhaya K.; Vohs, John M.; Wang, Yong; Palo, Daniel R.

    2008-03-07

    Pd/ZnO/Al2O3 catalysts were studied for water-gas-shift (WGS), methanol steam reforming, and reverse-water-gas-shift (RWGS) reactions. WGS activity was found to be dependent on the Pd:Zn ratio with a maximum activity obtained at approximately 0.50, which was comparable to that of a commercial Pt-based catalyst. The catalyst stability was demonstrated for 100 hours time-on-stream at a temperature of 3600C without evidence of metal sintering. WGS reaction rates were approximately 1st order with respect to CO concentration, and kinetic parameters were determined to be Ea = 58.3 kJ mol-1 and k0 = 6.1x107 min-1. During methanol steam reforming, the CO selectivities were observed to be lower than the calculated equilibrium values over a range of temperatures and steam/carbon ratios studied while the reaction rate constants were approximately of the same magnitude for both WGS and methanol steam reforming. These results indicate that although Pd/ZnO/Al2O3 are active WGS catalysts, WGS is not involved in methanol steam reforming. RWGS rate constants are on the order of about 20 times lower than that of methanol steam reforming, suggesting that RWGS reaction could be one of the sources for small amount of CO formation in methanol steam reforming.

  10. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    Science.gov (United States)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  11. Two Noveland Simple Correlations to Estimate Equilibrium Water Dew Point for Natural Gas Dehydration Process

    Directory of Open Access Journals (Sweden)

    Leonel Alberto Benitez

    2014-04-01

    Full Text Available Water is probably the most undesirable component found in crude natural gas because its presence can produce hydrate formation, and it can also lead to corrosion or erosion problems in pipes and equipment. Natural gas must be dehydrated before being transported through a long distance to ensure an efficient and trouble-free operation. Thermodynamic modelling of triethyleneglycol (TEG-water system is still rather inaccurate, especially with regard to systems at high temperature and high TEG concentration. As a consequence, design and operation of absorber towers are affected by the lack of accurate data. Two novel correlations have been developed to estimate the equilibrium water dew point of a natural gas stream by evaluating experimental data and literature. These data were collected and analyzed by means of images scanned with MATLAB software R2012B version. An average percentage error is of 1-2% for linear correlation and it is of 2-3% for non-linear correlation. Results are quite accurate and they are consistent with literature data. Due to the simplicity and precision of the correlations developed in this work, the equations obtained have a great practical value. Consequently, they allow process engineers to perform a quick check of the water dew point at different conditions without using complex expressions or graphics.

  12. Soil Erosion and Surface Water Quality Impacts of Natural Gas Development in East Texas, USA

    Directory of Open Access Journals (Sweden)

    Matthew McBroom

    2012-11-01

    Full Text Available Due to greater demands for hydrocarbons and improvements in drilling technology, development of oil and natural gas in some regions of the United States has increased dramatically. A 1.4 ha natural gas well pad was constructed in an intermittent stream channel at the Alto Experimental Watersheds in East Texas, USA (F1, while another 1.1 ha well pad was offset about 15 m from a nearby intermittent stream (F2. V-notch weirs were constructed downstream of these well pads and stream sedimentation and water quality was measured. For the 2009 water year, about 11.76 cm, or almost 222% more runoff resulted from F1 than F2. Sediment yield was significantly greater at F1, with 13,972 kg ha−1 yr−1 versus 714 kg ha−1yr−1 at F2 on a per unit area disturbance basis for the 2009 water year. These losses were greater than was observed following forest clearcutting with best management practices (111–224 kg ha−1. Significantly greater nitrogen and phosphorus losses were measured at F1 than F2. While oil and gas development can degrade surface water quality, appropriate conservation practices like retaining streamside buffers can mitigate these impacts.

  13. Algal growth and community structure in a mixed-culture system using coal seam gas water as the water source.

    Science.gov (United States)

    Buchanan, Jessica J; Slater, Frances R; Bai, Xue; Pratt, Steven

    2013-01-01

    Coal seam gas (CSG) is being touted as a transition fuel as the world moves towards low-carbon economies. However, the development of CSG reserves will generate enormous volumes of saline water. In this work, we investigate the potential of using this saline water to support mass algae production. Water and brine from a CSG water treatment facility (1.6 and 11.6 g total dissolved solids per litre (TDS L(-1)) respectively) were inoculated with algal biomass from freshwater and seawater environments and supplemented with nutrients in open, fed-batch reactors. Significant algal growth was recorded, with maximum specific growth rates in CSG water and CSG brine of 0.20 +/- 0.05 d(-1) and 0.26 +/- 0.04 d(-1) respectively. These maximum specific growth rates were equal to or greater than specific growth rates in deionized water and seawater diluted to the same salinity. However, algal growth lag time in CSG brine was between 7 and 9 times longer than in other waters. Microscopy and terminal-restriction fragment length polymorphism (T-RFLP) were used to monitor community structure in the reactors. The same few algal species dominated all of the reactors, except for the CSG brine reactor at day 15. This result indicates that conditions in CSG brine select for different species of algae compared to seawater of the same salinity and other waters tested. The findings suggest that mass algae production in CSG water is feasible but algae community composition may be a function of CSG water chemistry. This has implications for the downstream use of algae.

  14. Gas Shale Capillary Pressure - Saturation Relations Determined using a Water Activity Meter

    Science.gov (United States)

    Perfect, E.; Donnelly, B.; McKay, L. D.; Lemiszki, P. J.; DiStefano, V. H.; Anovitz, L. M.; McFarlane, J.; Hale, R. E.; Cheng, C. L.

    2016-12-01

    Capillary pressure is the pressure difference across the interface between two immiscible fluids in a porous medium. It is related to properties of the fluids, properties of the solid matrix, and the history of wetting and drying (hysteresis). Capillary pressure increases as the degree of wetting fluid saturation decreases. The petroleum industry commonly employs parameters describing the air - water capillary pressure - saturation relationship in numerical reservoir models. Traditional methods of measuring this relationship are unsuitable for the characterization of gas shales due to their inability to measure the high capillary pressures associated with small pores. A possible alternative method is the water activity meter which is widely used in the soil sciences. However, its application to lithified material has been limited. This study utilized a water activity meter to measure air - water capillary pressures (ranging from 1.3 - 219.6 MPa) at several water saturation levels (measured gravimetrically) in both the wetting and drying directions. Seven types of gas producing shale with different porosities (2.5 - 13.6%) and total organic carbon contents (0.4 - 13.5%) were investigated. Nonlinear regression was used to fit the resulting capillary pressure - water saturation data pairs for each shale type to the Brooks and Corey (BC) equation. This equation successfully fitted data for 6 of the 7 shale types investigated (median R2 = 0.93) indicating the water activity meter is a viable method for characterizing capillary pressure - saturation relationships for inclusion in numerical reservoir models. As expected, the different shale types had statistically different BC parameters. However, there were no significant differences between the BC parameters for the wetting versus drying data sets suggesting hysteresis was negligible and can be ignored when simulating production and leakoff in gas shales.

  15. Origin of interfacial nanoscopic gaseous domains and formation of dense gas layer at hydrophobic solid-water interface.

    Science.gov (United States)

    Peng, Hong; Birkett, Greg R; Nguyen, Anh V

    2013-12-10

    Interfacial gas enrichment (IGE) covering the entire area of hydrophobic solid-water interface has recently been detected by atomic force microscopy (AFM) and hypothesized to be responsible for the unexpected stability and anomalous contact angle of gaseous nanobubbles and the significant change from DLVO to non-DLVO forces. In this paper, we provide further proof of the existence of IGE in the form of a dense gas layer (DGL) by molecular dynamic simulation. Nitrogen gas adsorption at the water-graphite interface is investigated using molecular dynamic simulation at 300 K and 1 atm normal pressure. The results show that a DGL with a density equivalent to a gas at pressure of 500 atm is formed and equilibrated with a normal pressure of 1 atm. By varying the number of gas molecules in the system, we observe several types of dense gas domains: aggregates, cylindrical caps, and DGLs. Spherical cap gas domains form during the simulation but are unstable and always revert to another type of gas domain. Furthermore, the calculated surface potential of the DGL-water interface, -17.5 mV, is significantly closer to 0 than the surface potential, -65 mV, of normal gas bubble-water interface. This result supports our previously stated hypothesis that the change in surface potential causes the switch from repulsion to attraction for an AFM tip when the graphite surface is covered by an IGE layer. The change in surface potential comes from the structure change of water molecules at the DGL-water interface as compared with the normal gas-water interface. In addition, the contact angle of the cylindrical cap high density nitrogen gas domains is 141°. This contact angle is far greater than 85° observed for water on graphite at ambient conditions and much closer to the 150° contact angle observed for nanobubbles in experiments.

  16. Fouling of microfiltration membranes by flowback and produced waters from the Marcellus shale gas play.

    Science.gov (United States)

    Xiong, Boya; Zydney, Andrew L; Kumar, Manish

    2016-08-01

    There is growing interest in possible options for treatment or reuse of flowback and produced waters from natural gas processing. Here we investigated the fouling characteristics during microfiltration of different flowback and produced waters from hydraulic fracturing sites in the Marcellus shale. All samples caused severe and highly variable fouling, although there was no direct correlation between the fouling rate and total suspended solids, turbidity, or total organic carbon. Furthermore, the fouling of water after prefiltration through a 0.2 μm membrane was also highly variable. Low fouling seen with prefiltered water was mainly due to removal of submicron particles 0.4-0.8 μm during prefiltration. High fouling seen with prefiltered water was mainly caused by a combination of hydrophobic organics and colloidal particles membranes. The small colloidal particles were highly stable, likely due to the surfactants and other organics present in the fracking fluids. The colloid concentration was as high as 10(11) colloids/ml, which is more than 100 times greater than that in typical seawater. Furthermore, these colloids were only partially removed by MF, causing substantial fouling during a subsequent ultrafiltration. These results clearly show the importance of organics and colloidal material in membrane fouling caused by flowback and produced waters, which is of critical importance in the development of more sustainable treatment strategies in natural gas processing.

  17. Greenhouse gas emissions, irrigation water use, and arsenic concentrations; a common thread in rice water management

    Science.gov (United States)

    Rice has historically been grown as a flooded crop in the United States. As competition for water resources has grown, there is interest in reducing water use in rice production so as to maintain a viable and sustainable rice industry into the future. An irrigation study was established in 2011 at ...

  18. Data cleaning methodology for monthly water-to-oil and water-to-gas production ratios in continuous resource assessments

    Science.gov (United States)

    Varela, Brian A.; Haines, Seth S.; Gianoutsos, Nicholas J.

    2017-01-19

    Petroleum production data are usually stored in a format that makes it easy to determine the year and month production started, if there are any breaks, and when production ends. However, in some cases, you may want to compare production runs where the start of production for all wells starts at month one regardless of the year the wells started producing. This report describes the JAVA program the U.S. Geological Survey developed to examine water-to-oil and water-to-gas ratios in the form of month 1, month 2, and so on with the objective of estimating quantities of water and proppant used in low-permeability petroleum production. The text covers the data used by the program, the challenges with production data, the program logic for checking the quality of the production data, and the program logic for checking the completeness of the data.

  19. A road damage and life-cycle greenhouse gas comparison of trucking and pipeline water delivery systems for hydraulically fractured oil and gas field development in Colorado.

    Science.gov (United States)

    Duthu, Ray C; Bradley, Thomas H

    2017-01-01

    The process of hydraulic fracturing for recovery of oil and natural gas uses large amounts of fresh water and produces a comparable amount of wastewater, much of which is typically transported by truck. Truck transport of water is an expensive and energy-intensive process with significant external costs including roads damages, and pollution. The integrated development plan (IDP) is the industry nomenclature for an integrated oil and gas infrastructure system incorporating pipeline-based transport of water and wastewater, centralized water treatment, and high rates of wastewater recycling. These IDP have been proposed as an alternative to truck transport systems so as to mitigate many of the economic and environmental problems associated with natural gas production, but the economic and environmental performance of these systems have not been analyzed to date. This study presents a quantification of lifecycle greenhouse gas (GHG) emissions and road damages of a generic oil and gas field, and of an oil and gas development sited in the Denver-Julesburg basin in the northern Colorado region of the US. Results demonstrate that a reduction in economic and environmental externalities can be derived from the development of these IDP-based pipeline water transportation systems. IDPs have marginal utility in reducing GHG emissions and road damage when they are used to replace in-field water transport, but can reduce GHG emissions and road damage by factors of as much as 6 and 7 respectively, when used to replace fresh water transport and waste-disposal routes for exemplar Northern Colorado oil and gas fields.

  20. Study for Reduction of Outgassing Property of Adsorbed Water Gas for Improved Surface Finished Titanium Material

    Science.gov (United States)

    Takeda, Masatoshi; Kurisu, Hiroki; Uchida, Takashi; Yamamoto, Setsuo; Ishizawa, Katsunobu; Nomura, Takeru; Eda, Takahiro; Murashige, Nobuyuki

    This paper addresses the development of the surface finishing for a titanium material and the study for the reduction of outgassing property of adsorbed water (H2O) molecules. Developed surface finishing is composed of the buffing for the reduction of the surface roughness and improved chemical polishing for the thick surface oxide layer compared with the chemical polishing so far. The surface roughness of the surface finished titanium material is reduced 35% and the thickness of the surface oxide layer increases by 30%. The total amount of thermal desorbed H2O gas for the new surface finished titanium is reduced 30%. It is considered that the origin for the decrease of the amount of desorption H2O gas is the reduction of the adsorption sites due to the decrease of the surface roughness and the reduction of adsorption energy of H2O gas due to the strong surface oxidation for a titanium material.

  1. Microfluidic generation of uniform water droplets using gas as the continuous phase.

    Science.gov (United States)

    Jiang, Kunqiang; Lu, Annie Xi; Dimitrakopoulos, Panagiotis; DeVoe, Don L; Raghavan, Srinivasa R

    2015-06-15

    Microfluidic schemes for forming uniform aqueous microdroplets usually rely on contacting the aqueous liquid (dispersed phase) with an immiscible oil (continuous phase). Here, we demonstrate that the oil can be substituted with gas (nitrogen or air) while still retaining the ability to generate discrete and uniform aqueous droplets. Our device is a capillary co-flow system, with the inner flow of water getting periodically dispersed into droplets by the external flow of gas. The droplet size and different formation modes can be tuned by varying the liquid and gas flow rates. Importantly, we identify the range of conditions that correspond to the "dripping mode", i.e., where discrete droplets are consistently generated with no satellites. We believe this is a significant development that will be beneficial for chemical and biological applications requiring clean and contaminant-free droplets, including DNA amplification, drug encapsulation, and microfluidic cell culture.

  2. Prevention of the water flooding by micronizing the pore structure of gas diffusion layer for polymer electrolyte fuel cell

    Science.gov (United States)

    Hiramitsu, Yusuke; Sato, Hitoshi; Hori, Michio

    In polymer electrolyte fuel cells, high humidity must be established to maintain high proton conductivity in the polymer electrolyte. However, the water that is produced electrochemically at the cathode catalyst layer can condense in the cell and cause an obstruction to the diffusion of reaction gas in the gas diffusion layer and the gas channel. This leads to a sudden decrease of the cell voltage. To combat this, strict water management techniques are required, which usually focus on the gas diffusion layer. In this study, the use of specially treated carbon paper as a flood-proof gas diffusion layer under extremely high humidity conditions was investigated experimentally. The results indicated that flooding originates at the interface between the gas diffusion layer and the catalyst layer, and that such flooding could be eliminated by control of the pore size in the gas diffusion layer at this interface.

  3. Application of an industrial gas supply system to a hydrogen water chemistry installation

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, D.; Kuberka, K.A.

    1988-01-01

    Equipment for a hydrogen gas supply and an oxygen gas supply was adapted to meet operating safety criteria for a hydrogen water chemistry (HWC) application at a boiling water reactor (BWR) plant. The oxygen and hydrogen gases are supplied by vaporizing cryogenic liquid drawn from storage tanks. Cryogenic storage tanks consist of an inner vessel supported within an outer vessel, with insulation in the space between vessels. The supports and product lines on the inner container are small and flexible for heat transfer and thermal flexibility considerations. Cryogenic storage tank systems inherently have low natural frequencies and must be analyzed for dynamic response to site seismic criteria. Equipment modifications to meet application criteria were made without compromising performance. The guidelines for HWC installations were supplemented by a comprehensive design safety review to assess the equipment safeguards required to control potential product releases.

  4. Polymer injection for stimulation or plugging of oil, gas or water wells

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, I.; Kretzschmar, H.J.; Czolbe, P.; Bittkow, P.; Wassermann, I.

    1988-01-01

    Polymer solutions are appropriate not only for mobility control of flooding volume but for an even wider range of applications, e.g. as a working fluid in and around the well. Owing to adjustible fluidic properties of polymer solutions to which by variation of recipe even rubber seal quality can be given, methods of well-treatment for temporary or permanent, selective or complete tightening have become possible. Selective water sealing applied to oil wells in Hungary resulted in additional oil recovery at low cost. In gas wells this method has not yet stood its test, however, resulted in reduced water/gas-ratio. Complete inflow-preventive tightening to the effect of secondary sealing or plugging of wells has become an established technique. Further applications, e.g. inside drilling holes and behind casings, are possible.

  5. Water and gas seepage at the Salton Sea Geothermal System (California, USA)

    Science.gov (United States)

    Mazzini, A.; Svensen, H.; Polteau, S.; Planke, S.

    2009-04-01

    The Davis-Schrimpf seep field (Salton Sea, California) represents an ideal site for investigating the activity of hydrothermal systems. At this site, dozens of seeps (gryphons-pools) constantly expel water, mud, gas, and petroleum-fluids. We have conducted a long term monitoring on water and gas geochemistry of fluids erupted as well as annual temperature records. The fluids geochemistry and the temperature vary significantly at closely spaced locations and the water content present in the seeps acts as a key factor. The water salinity varies between fresh (1-3 g/L) in the gryphons, to hypersaline brine (145 g/L) in the pools. The gas emitted by the main vents revealed a composition averagely dominated by C02 (up to 99%) with smaller contributions of CH4. The seep waters represent meteoric waters modified by surface evaporation, with little or no evidence for a deep hydrothermal component. Seep gases, on the other hand, have a deep metamorphic/mantle origin. Temperature monitoring shows that gryphons are dominated by hydrothermal input and the pools by diurnal variations in air temperature. More recently we have conducted a broad investigation of the flux of CO2 and CH4 on a 20x20m meters grid covering a surface of over 20,000 square meters. The survey area extends over the main focussed vents and the results show that a considerable amount of CO2 and is constantly seeping through microseepage. Locally CH4 also exhibits areas with strong microseepage mainly where higher temperatures and surface minerals precipitations occur. These data reveal how important is the effect of microseepage when calculating global budgets of CO2 emissions in hydrothermal fields.

  6. Portable mixed abrasive water jet equipment for rescue in high gas mine shaft

    Institute of Scientific and Technical Information of China (English)

    ZENG Rui; DU Chang-long; XU Rui; ZHAO Jing

    2011-01-01

    In order to rescue a trapped miner and clean out roadways quickly in a high gas mine shaft after a mining mishap, a special portable cold-cutting equipment is needed, the main technology parameters were calculated according to the advanced cold-cutting technology of high pressure abrasive water jet and the portable mixed abrasive water jet equipment (PAWE) was designed to meet the needs of emergency rescue in high gas mine shafts. Tested the PAWE in a high gas environment, and the result shows that the maximum cutting depth of solid iron pipe is 18 mm and the recoilforce of the sprayer is 28.9 N under the conditions that actual cutting pressure is 29 MPa, starting target distance is 10 mm, cutting speed is 180 mm/min and concentration of abrasive is 32%. The course of the experiment in the high gas environment was smooth and continuous, without any explosion. The PAWE is easy to move and operate, but the nozzle which was worn badly in the sprayer should be changed every 8 minutes.

  7. Coalbed Methane Procduced Water Treatment Using Gas Hydrate Formation at the Wellhead

    Energy Technology Data Exchange (ETDEWEB)

    BC Technologies

    2009-12-30

    Water associated with coalbed methane (CBM) production is a significant and costly process waste stream, and economic treatment and/or disposal of this water is often the key to successful and profitable CBM development. In the past decade, advances have been made in the treatment of CBM produced water. However, produced water generally must be transported in some fashion to a centralized treatment and/or disposal facility. The cost of transporting this water, whether through the development of a water distribution system or by truck, is often greater than the cost of treatment or disposal. To address this economic issue, BC Technologies (BCT), in collaboration with Oak Ridge National Laboratory (ORNL) and International Petroleum Environmental Consortium (IPEC), proposed developing a mechanical unit that could be used to treat CBM produced water by forming gas hydrates at the wellhead. This process involves creating a gas hydrate, washing it and then disassociating hydrate into water and gas molecules. The application of this technology results in three process streams: purified water, brine, and gas. The purified water can be discharged or reused for a variety of beneficial purposes and the smaller brine can be disposed of using conventional strategies. The overall objectives of this research are to develop a new treatment method for produced water where it could be purified directly at the wellhead, to determine the effectiveness of hydrate formation for the treatment of produced water with proof of concept laboratory experiments, to design a prototype-scale injector and test it in the laboratory under realistic wellhead conditions, and to demonstrate the technology under field conditions. By treating the water on-site, producers could substantially reduce their surface handling costs and economically remove impurities to a quality that would support beneficial use. Batch bench-scale experiments of the hydrate formation process and research conducted at ORNL

  8. Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

    OpenAIRE

    Cadena-Pereda, Raúl O.; Anaya-Rivera, Ely K.; Gilberto Herrera-Ruiz; Eric M. Rivera-Muñoz; Gomez-Melendez, Domingo J.

    2012-01-01

    Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such a...

  9. Stability of Fluorosurfactant Adsorption on Mineral Surface for Water Removal in Tight Gas Reservoirs

    OpenAIRE

    Lijun You; Wanchun Zhang; Yili Kang; Zhangxin Chen; Xuefen Liu

    2015-01-01

    Long-term effectiveness of rock wettability alteration for water removal during gas production from tight reservoir depends on the surfactant adsorption on the pore surface of a reservoir. This paper selected typical cationic fluorosurfactant FW-134 as an example and took advantage of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM) to investigate its adsorption stability on the rock mineral surface under the oscillation...

  10. Enhancement of water-gas shift reaction efficiency: catalysts and the catalyst bed arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Baronskaya, Natal' ya A; Minyukova, Tat' yana P; Khassin, Aleksandr A; Yurieva, Tamara M; Parmon, Valentin N [G.K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2010-12-29

    The results of studies devoted to the search for catalysts of water-gas shift (WGS) reaction that are highly active in a wide temperature interval are generalized. New compositions based on traditional and alternative, as regards the chemical composition, catalysts of high- and low-temperature WGS reaction are considered in detail. The single-stage arrangement of WGS reaction ensuring small temperature gradients in the radial direction of the catalyst bed are discussed.

  11. Flow resistance reduction of coal water slurry through gas phase addition

    OpenAIRE

    Robak Jolanta; Ignasiak Karina

    2016-01-01

    One of the main advantages of coal water slurry fuel (CWS) is a physical form that allows, among others, their transfer by pipelines over long distances. For this form of transport actions towards reducing the flow resistance of the transmitted medium are important. One of the treatments leading to reduction in the flow resistance of suspensions is to introduce gas into the stream of flowing slurry. The goal of that action is to either loosen the structure of densely packed grains or increase...

  12. Methodology for Calculation of Pressure Impulse Distribution at Gas-Impulse Regeneration of Water Well Filters

    Directory of Open Access Journals (Sweden)

    V. V. Ivashechkin

    2010-01-01

    Full Text Available The paper considers a mathematical model for process of pressure impulse distribution in a water well which appear as a result of underwater gas explosions in cylindrical and spherical explosive chambers with elastic shells and in a rigid cylindrical chamber which is open from the bottom. The proposed calculation methodology developed on the basis of the mathematical model makes it possible to determine pressure in the impulse on a filter wall and at any point of a water well pre-filter zone. 

  13. Summary of research and development effort on air and water cooling of gas turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Fraas, A.P.

    1980-03-01

    The review on air- and water-cooled gas turbines from the 1904 Lemale-Armengaud water-cooled gas turbine, the 1948 to 1952 NACA work, and the program at GE indicates that the potential of air cooling has been largely exploited in reaching temperatures of 1100/sup 0/C (approx. 2000/sup 0/F) in utility service and that further increases in turbine inlet temperature may be obtained with water cooling. The local heat flux in the first-stage turbine rotor with water cooling is very high, yielding high-temperature gradients and severe thermal stresses. Analyses and tests indicate that by employing a blade with an outer cladding of an approx. 1-mm-thick oxidation-resistant high-nickel alloy, a sublayer of a high-thermal-conductivity, high-strength, copper alloy containing closely spaced cooling passages approx. 2 mm in ID to minimize thermal gradients, and a central high-strength alloy structural spar, it appears possible to operate a water-cooled gas turbine with an inlet gas temperature of 1370/sup 0/C. The cooling-water passages must be lined with an iron-chrome-nickel alloy must be bent 90/sup 0/ to extend in a neatly spaced array through the platform at the base of the blade. The complex geometry of the blade design presents truly formidable fabrication problems. The water flow rate to each of many thousands of coolant passages must be metered and held to within rather close limits because the heat flux is so high that a local flow interruption of only a few seconds would lead to a serious failure.Heat losses to the cooling water will run approx. 10% of the heat from the fuel. By recoverying this waste heat for feedwater heating in a command cycle, these heat losses will give a degradation in the power plant output of approx. 5% relative to what might be obtained if no cooling were required. However, the associated power loss is less than half that to be expected with an elegant air cooling system.

  14. Acclimation of a terrestrial plant to submergence facilitates gas exchange under water

    DEFF Research Database (Denmark)

    Mommer, L.; Pedersen, O.; Visser, E. J. W.

    2004-01-01

    . The present study demonstrates that the internal oxygen pressure in the petioles of Rumex palustris plants under water is indeed well above the critical oxygen pressure for aerobic respiration, provided that the air-saturated water is not completely stagnant. The beneficial effect of shoot acclimation...... of this terrestrial plant species to submergence for gas exchange capacity is also shown. Shoot acclimation to submergence involved a reduction of the diffusion resistance to gases, which was not only functional by increasing diffusion of oxygen into the plant, but also by increasing influx of CO2, which enhances...

  15. Prediction of water formation temperature in natural gas dehydrators using radial basis function (RBF neural networks

    Directory of Open Access Journals (Sweden)

    Tatar Afshin

    2016-03-01

    Full Text Available Raw natural gases usually contain water. It is very important to remove the water from these gases through dehydration processes due to economic reasons and safety considerations. One of the most important methods for water removal from these gases is using dehydration units which use Triethylene glycol (TEG. The TEG concentration at which all water is removed and dew point characteristics of mixture are two important parameters, which should be taken into account in TEG dehydration system. Hence, developing a reliable and accurate model to predict the performance of such a system seems to be very important in gas engineering operations. This study highlights the use of intelligent modeling techniques such as Multilayer perceptron (MLP and Radial Basis Function Neural Network (RBF-ANN to predict the equilibrium water dew point in a stream of natural gas based on the TEG concentration of stream and contractor temperature. Literature data set used in this study covers temperatures from 10 °C to 80 °C and TEG concentrations from 90.000% to 99.999%. Results showed that both models are accurate in prediction of experimental data and the MLP model gives more accurate predictions compared to RBF model.

  16. Sustainable Management of Flowback Water during Hydraulic Fracturing of Marcellus Shale for Natural Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Vidic, Radisav [Univ. of Pittsburgh, PA (United States)

    2015-01-24

    This study evaluated the feasibility of using abandoned mine drainage (AMD) as make- up water for the reuse of produced water for hydraulic fracturing. There is an abundance of AMD sources near permitted gas wells as documented in this study that can not only serve as makeup water and reduce the demand on high quality water resources but can also as a source of chemicals to treat produced water prior to reuse. The assessment of AMD availability for this purpose based on proximity and relevant regulations was accompanied by bench- and pilot-scale studies to determine optimal treatment to achieve desired water quality for use in hydraulic fracturing. Sulfate ions that are often present in AMD at elevated levels will react with Ba²⁺ and Sr²⁺ in produced water to form insoluble sulfate compounds. Both membrane microfiltration and gravity separation were evaluated for the removal of solids formed as a result of mixing these two impaired waters. Laboratory studies revealed that neither AMD nor barite formed in solution had significant impact on membrane filtration but that some produced waters contained submicron particles that can cause severe fouling of microfiltration membrane. Coagulation/flocculation was found to be an effective process for the removal of suspended solids and both bench- and pilot-scale studies revealed that optimal process conditions can consistently achieve the turbidity of the finished water below 5 NTU. Adjusting the blending ratio of AMD and produced water can achieve the desired effluent sulfate concentration that can be accurately predicted by chemical thermodynamics. Co-treatment of produced water and AMD will result in elevated levels of naturally occurring radioactive materials (NORM) in the solid waste generated in this process due to radium co-precipitation with barium sulfate. Laboratory studies revealed that the mobility of barite that may form in the subsurface due to the presence of sulfate in the fracturing fluid can be

  17. TREATMENT OF PRODUCED OIL AND GAS WATERS WITH SURFACTANT-MODIFIED ZEOLITE

    Energy Technology Data Exchange (ETDEWEB)

    Lynn E. Katz; R.S. Bowman; E.J. Sullivan

    2003-11-01

    Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. It is by some estimates the largest single waste stream in the country, aside from nonhazardous industrial wastes. Characteristics of produced water include high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component, and chemicals added during the oil-production process. While most of the produced water is disposed via reinjection, some must be treated to remove organic constituents before the water is discharged. Current treatment options are successful in reducing the organic content; however, they cannot always meet the levels of current or proposed regulations for discharged water. Therefore, an efficient, cost-effective treatment technology is needed. Surfactant-modified zeolite (SMZ) has been used successfully to treat contaminated ground water for organic and inorganic constituents. In addition, the low cost of natural zeolites makes their use attractive in water-treatment applications. This report summarizes the work and results of this four-year project. We tested the effectiveness of surfactant-modified zeolite (SMZ) for removal of BTEX with batch and column experiments using waters with BTEX concentrations that are comparable to those of produced waters. The data from our experimental investigations showed that BTEX sorption to SMZ can be described by a linear isotherm model, and competitive effects between compounds were not significant. The SMZ can be readily regenerated using air stripping. We field-tested a prototype SMZ-based water treatment system at produced water treatment facilities and found that the SMZ successfully removes BTEX from produced waters as predicted by laboratory studies. When compared to other existing treatment technologies, the cost of the SMZ system is very competitive. Furthermore, the SMZ system is relatively compact, does not require the storage of

  18. Use of Drinking Water Sludge as Adsorbent for H2S Gas Removal from Biogas

    Directory of Open Access Journals (Sweden)

    Sucheela Polruang

    2017-01-01

    Full Text Available This paper reports the results of a research project, which attempts to produce a low-cost adsorbent material from waste (drinking water sludge. The main objective of this work is to study the characteristics of drinking water sludge for its adsorptive properties including morphology, surface area, porosity and chemical composition. The effect of activation conditions on H2S gas adsorption efficiency of drinking water sludge was experimented. In this study, raw drinking water sludge was divided into 3 groups. In the first group, drinking water sludge was only oven dried at 105°C. For the other 2 groups, drinking water sludge was soaked in 2.5 M NaOH solution. After soaking, the sludge was divided into 2 groups (group 2 and 3. The second group was washed with distilled water until pH 7; while the third group was not. Biogas from a swine farm was used with an initial H2S gas concentration in the range of 2,000 - 4,000 ppm. The material analysis showed that more surface area and total volume of sludge can be obtained after activated with NaOH. From the adsorption experiments, it was found that the highest adsorption capacity (qe of 87.94 mg H2S/g adsorptive material can be achieved by using sludge from the third group. Moreover, by adding of 20 wt% iron filing into sludge of the third group the adsorption capacity increased to 105.22 mg H2S/g adsorptive material. Drinking water sludge can be considered as a high potential energy saving and low cost adsorbent for removal of H2S.

  19. Effect of mustard gas hydrolysis products on the development of water-bloom forming cyanobacteria

    Directory of Open Access Journals (Sweden)

    Zaytseva Tatyana

    2017-03-01

    Full Text Available Mustard gas and its hydrolysis products (MGHP belong to stable organochlorine compounds with high toxicity and broad spectrum of activity. Since the Second World War many aquatic ecosystems including the Baltic and the Adriatic Sea as well as the coastal waters of Japan, the USA, the UK, Australia have been contaminated with mustard gas due to the dumping of chemical weapon. Mustard gas and its hydrolysis products have a negative impact on aquatic life including microbiota. The aim of this work was to define the effect of MGHP on the growth, photosynthetic activity and synthesis of secondary metabolites by water-bloom forming cyanobacteria Trichormus variabilis, Aphanizomenon flos-aquae, Microcystis aeruginosa, Nodularia spumigena. Microbiological, chromatographic, spectrophotometric methods were used. The growth inhibition test with MGHP on cyanobacteria showed influence on the concentration EC50 within the range of 5.5 – 11.2 mg of organochlorine compounds (ОCC per liter. The synthesis of chlorophyll a was also decreased. It was shown that the chlorophyll synthesis was more sensitive to MGHP than the growth of cyanobacteria. NGHP induced enhanced excretion of exopolysaccharides. Low concentration of MGHP – 0.3 mg OCC/l - promoted the growth of toxigenic cyanobacterium Microcystis aeruginosa and increased microcystin-LR concentration in the environment. enhanced excretion of such metabolites as polysaccharides and cyanotoxins has a serious negative impact on water pollution due to MGHP.

  20. Advances of zeolite based membrane for hydrogen production via water gas shift reaction

    Science.gov (United States)

    Makertihartha, I. G. B. N.; Zunita, M.; Rizki, Z.; Dharmawijaya, P. T.

    2017-07-01

    Hydrogen is considered as a promising energy vector which can be obtained from various renewable sources. However, an efficient hydrogen production technology is still challenging. One technology to produce hydrogen with very high capacity with low cost is through water gas shift (WGS) reaction. Water gas shift reaction is an equilibrium reaction that produces hydrogen from syngas mixture by the introduction of steam. Conventional WGS reaction employs two or more reactors in series with inter-cooling to maximize conversion for a given volume of catalyst. Membrane reactor as new technology can cope several drawbacks of conventional reactor by removing reaction product and the reaction will favour towards product formation. Zeolite has properties namely high temperature, chemical resistant, and low price makes it suitable for membrane reactor applications. Moreover, it has been employed for years as hydrogen selective layer. This review paper is focusing on the development of membrane reactor for efficient water gas shift reaction to produce high purity hydrogen and carbon dioxide. Development of membrane reactor is discussed further related to its modification towards efficient reaction and separation from WGS reaction mixture. Moreover, zeolite framework suitable for WGS membrane reactor will be discussed more deeply.

  1. Determination of flow rates of oil, water and gas in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Roach, G.J.; Watt, J.S.; Zastawny, H.W. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lucas Heights, NSW (Australia). Div. of Mineral Physics

    1993-12-31

    This paper describes a multiphase flow meter developed by CSIRO for determining of the flow rates of oil, water and gas in high pressure pipelines, and the results of a trial of this flow meter on an offshore oil platform. Two gamma-ray transmission gauges are mounted about a pipeline carrying the full flow of oil, water and gas. The flow rates are determined by combining single energy gamma-ray transmission measurements which determine the mass per unit area of fluids in the gamma-ray beam as a function of time, dual energy gamma-ray transmission (DUET) which determine the approximate mass fraction of oil in the liquids, cross-correlation of gamma-ray transmission measurements, with one gauge upstream of the other, which determines flow velocity, pressure and temperature measurements, and knowledge of the specific gravities of oil and (salt) water, and solubility of the gas in the liquids, all as a function of pressure and temperature. 3 figs.

  2. Methane gas generation from waste water extraction process of crude palm oil in experimental digesters

    Science.gov (United States)

    Dillon, A.; Penafiel, R.; Garzón, P. V.; Ochoa, V.

    2015-12-01

    Industrial processes to extract crude palm oil, generates large amounts of waste water. High concentrations of COD, ST, SV, NH4 + and low solubility of O2, make the treatment of these effluents starts with anaerobic processes. The anaerobic digestion process has several advantages over aerobic degradation: lower operating costs (not aeration), low sludge production, methane gas generation. The 4 stages of anaerobic digestion are: hydrolysis, acidogenic, acetogenesis and methanogenesis. Through the action of enzymes synthesized by microbial consortia are met. The products of each step to serve as reagents is conducted as follows. The organic load times and cell hydraulic retention, solids content, nutrient availability, pH and temperature are factors that influence directly in biodigesters. The objectives of this presentation is to; characterize the microbial inoculum and water (from palm oil wasted water) to be used in biodigestores, make specific methanogenic activity in bioassays, acclimatize the microorganisms to produce methane gas using basal mineral medium with acetate for the input power, and to determine the production of methane gas digesters high organic load.

  3. Molecular density functional theory for water with liquid-gas coexistence and correct pressure

    Energy Technology Data Exchange (ETDEWEB)

    Jeanmairet, Guillaume, E-mail: g.jeanmairet@fkf.mpg.de; Levesque, Maximilien, E-mail: maximilien.levesque@ens.fr [École Normale Supérieure - PSL Research University, Département de Chimie, Sorbonne Universités - UPMC Univ. Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris (France); Sergiievskyi, Volodymyr [SIS2M, LIONS, CEA, Saclay (France); Borgis, Daniel [École Normale Supérieure - PSL Research University, Département de Chimie, Sorbonne Universités - UPMC Univ. Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris (France); Maison de la Simulation, USR 3441, CEA - CNRS - INRIA - Univ. Paris-Sud - Univ. de Versailles, 91191 Gif-sur-Yvette Cedex (France)

    2015-04-21

    The solvation of hydrophobic solutes in water is special because liquid and gas are almost at coexistence. In the common hypernetted chain approximation to integral equations, or equivalently in the homogenous reference fluid of molecular density functional theory, coexistence is not taken into account. Hydration structures and energies of nanometer-scale hydrophobic solutes are thus incorrect. In this article, we propose a bridge functional that corrects this thermodynamic inconsistency by introducing a metastable gas phase for the homogeneous solvent. We show how this can be done by a third order expansion of the functional around the bulk liquid density that imposes the right pressure and the correct second order derivatives. Although this theory is not limited to water, we apply it to study hydrophobic solvation in water at room temperature and pressure and compare the results to all-atom simulations. The solvation free energy of small molecular solutes like n-alkanes and hard sphere solutes whose radii range from angstroms to nanometers is now in quantitative agreement with reference all atom simulations. The macroscopic liquid-gas surface tension predicted by the theory is comparable to experiments. This theory gives an alternative to the empirical hard sphere bridge correction used so far by several authors.

  4. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.; Skaar, Don

    2014-01-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  5. Microbial Community Changes in Hydraulic Fracturing Fluids and Produced Water from Shale Gas Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, Arvind Murali; Hartsock, Angela; Bibby, Kyle J; Hammack, Richard W; Vidic, Radisav D; Gregory, Kelvin B

    2013-11-19

    Microbial communities associated with produced water from hydraulic fracturing are not well understood, and their deleterious activity can lead to significant increases in production costs and adverse environmental impacts. In this study, we compared the microbial ecology in prefracturing fluids (fracturing source water and fracturing fluid) and produced water at multiple time points from a natural gas well in southwestern Pennsylvania using 16S rRNA gene-based clone libraries, pyrosequencing, and quantitative PCR. The majority of the bacterial community in prefracturing fluids constituted aerobic species affiliated with the class Alphaproteobacteria. However, their relative abundance decreased in produced water with an increase in halotolerant, anaerobic/facultative anaerobic species affiliated with the classes Clostridia, Bacilli, Gammaproteobacteria, Epsilonproteobacteria, Bacteroidia, and Fusobacteria. Produced water collected at the last time point (day 187) consisted almost entirely of sequences similar to Clostridia and showed a decrease in bacterial abundance by 3 orders of magnitude compared to the prefracturing fluids and produced water samplesfrom earlier time points. Geochemical analysis showed that produced water contained higher concentrations of salts and total radioactivity compared to prefracturing fluids. This study provides evidence of long-term subsurface selection of the microbial community introduced through hydraulic fracturing, which may include significant implications for disinfection as well as reuse of produced water in future fracturing operations.

  6. Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

    Science.gov (United States)

    Post, David

    2017-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. The bioregional assessment programme has modelled the impacts of coal seam gas development on surface and groundwater resources in three regions of eastern Australia, namely the Clarence-Moreton, Gloucester, and Namoi regions. This presentation will discuss the

  7. Noble gases identify the mechanisms of fugitive gas contamination in drinking-water wells overlying the Marcellus and Barnett Shales.

    Science.gov (United States)

    Darrah, Thomas H; Vengosh, Avner; Jackson, Robert B; Warner, Nathaniel R; Poreda, Robert J

    2014-09-30

    Horizontal drilling and hydraulic fracturing have enhanced energy production but raised concerns about drinking-water contamination and other environmental impacts. Identifying the sources and mechanisms of contamination can help improve the environmental and economic sustainability of shale-gas extraction. We analyzed 113 and 20 samples from drinking-water wells overlying the Marcellus and Barnett Shales, respectively, examining hydrocarbon abundance and isotopic compositions (e.g., C2H6/CH4, δ(13)C-CH4) and providing, to our knowledge, the first comprehensive analyses of noble gases and their isotopes (e.g., (4)He, (20)Ne, (36)Ar) in groundwater near shale-gas wells. We addressed two questions. (i) Are elevated levels of hydrocarbon gases in drinking-water aquifers near gas wells natural or anthropogenic? (ii) If fugitive gas contamination exists, what mechanisms cause it? Against a backdrop of naturally occurring salt- and gas-rich groundwater, we identified eight discrete clusters of fugitive gas contamination, seven in Pennsylvania and one in Texas that showed increased contamination through time. Where fugitive gas contamination occurred, the relative proportions of thermogenic hydrocarbon gas (e.g., CH4, (4)He) were significantly higher (P well failure. Noble gas data appear to rule out gas contamination by upward migration from depth through overlying geological strata triggered by horizontal drilling or hydraulic fracturing.

  8. Water transport in the gas diffusion layer of a polymer electrolyte fuel cell : Dynamic Pore-Network Modeling

    NARCIS (Netherlands)

    Qin, C.

    2015-01-01

    The pore-scale modeling is a powerful tool for increasing our understanding of water transport in the fibrous gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). In this work, a new dynamic pore-network model for air-water flow in the GDL is developed. It incorporates water vapor tr

  9. Integrating geophysics and geochemistry to evaluate coalbed natural gas produced water disposal, Powder River Basin, Wyoming

    Science.gov (United States)

    Lipinski, Brian Andrew

    Production of methane from thick, extensive coalbeds in the Powder River Basin of Wyoming has created water management issues. More than 4.1 billion barrels of water have been produced with coalbed natural gas (CBNG) since 1997. Infiltration impoundments, which are the principal method used to dispose CBNG water, contribute to the recharge of underlying aquifers. Airborne electromagnetic surveys of an alluvial aquifer that has been receiving CBNG water effluent through infiltration impoundments since 2001 reveal produced water plumes within these aquifers and also provide insight into geomorphologic controls on resultant salinity levels. Geochemical data from the same aquifer reveal that CBNG water enriched in sodium and bicarbonate infiltrates and mixes with sodium-calcium-sulfate type alluvial groundwater, which subsequently may have migrated into the Powder River. The highly sodic produced water undergoes cation exchange reactions with native alluvial sediments as it infiltrates, exchanging sodium from solution for calcium and magnesium on montmorillonite clays. The reaction may ultimately reduce sediment permeability by clay dispersion. Strontium isotope data from CBNG wells discharging water into these impoundments indicate that the Anderson coalbed of the Fort Union Formation is dewatered due to production. Geophysical methods provide a broad-scale tool to monitor CBNG water disposal especially in areas where field based investigations are logistically prohibitive, but geochemical data are needed to reveal subsurface processes undetectable by geophysical techniques. The results of this research show that: (1) CBNG impoundments should not be located near streams because they can alter the surrounding hydraulic potential field forcing saline alluvial groundwater and eventually CBNG water into the stream, (2) point bars are poor impoundment locations because they are essentially in direct hydraulic communication with the associated stream and because plants

  10. GIS based location optimization for mobile produced water treatment facilities in shale gas operations

    Science.gov (United States)

    Kitwadkar, Amol Hanmant

    Over 60% of the nation's total energy is supplied by oil and natural gas together and this demand for energy will continue to grow in the future (Radler et al. 2012). The growing demand is pushing the exploration and exploitation of onshore oil and natural gas reservoirs. Hydraulic fracturing has proven to not only create jobs and achieve economic growth, but also has proven to exert a lot of stress on natural resources---such as water. As water is one of the most important factors in the world of hydraulic fracturing, proper fluids management during the development of a field of operation is perhaps the key element to address a lot of these issues. Almost 30% of the water used during hydraulic fracturing comes out of the well in the form of flowback water during the first month after the well is fractured (Bai et. al. 2012). Handling this large amount of water coming out of the newly fractured wells is one of the major issues as the volume of the water after this period drops off and remains constant for a long time (Bai et. al. 2012) and permanent facilities can be constructed to take care of the water over a longer period. This paper illustrates development of a GIS based tool for optimizing the location of a mobile produced water treatment facility while development is still occurring. A methodology was developed based on a multi criteria decision analysis (MCDA) to optimize the location of the mobile treatment facilities. The criteria for MCDA include well density, ease of access (from roads considering truck hauls) and piping minimization if piping is used and water volume produced. The area of study is 72 square miles east of Greeley, CO in the Wattenberg Field in northeastern Colorado that will be developed for oil and gas production starting in the year 2014. A quarterly analysis is done so that we can observe the effect of future development plans and current circumstances on the location as we move from quarter to quarter. This will help the operators to

  11. Influence of infrastructure on water quality and greenhouse gas dynamics in urban streams

    Science.gov (United States)

    Smith, Rose M.; Kaushal, Sujay S.; Beaulieu, Jake J.; Pennino, Michael J.; Welty, Claire

    2017-06-01

    Streams and rivers are significant sources of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) globally, and watershed management can alter greenhouse gas (GHG) emissions from streams. We hypothesized that urban infrastructure significantly alters downstream water quality and contributes to variability in GHG saturation and emissions. We measured gas saturation and estimated emission rates in headwaters of two urban stream networks (Red Run and Dead Run) of the Baltimore Ecosystem Study Long-Term Ecological Research project. We identified four combinations of stormwater and sanitary infrastructure present in these watersheds, including: (1) stream burial, (2) inline stormwater wetlands, (3) riparian/floodplain preservation, and (4) septic systems. We selected two first-order catchments in each of these categories and measured GHG concentrations, emissions, and dissolved inorganic and organic carbon (DIC and DOC) and nutrient concentrations biweekly for 1 year. From a water quality perspective, the DOC : NO3- ratio of streamwater was significantly different across infrastructure categories. Multiple linear regressions including DOC : NO3- and other variables (dissolved oxygen, DO; total dissolved nitrogen, TDN; and temperature) explained much of the statistical variation in nitrous oxide (N2O, r2 = 0.78), carbon dioxide (CO2, r2 = 0.78), and methane (CH4, r2 = 0.50) saturation in stream water. We measured N2O saturation ratios, which were among the highest reported in the literature for streams, ranging from 1.1 to 47 across all sites and dates. N2O saturation ratios were highest in streams draining watersheds with septic systems and strongly correlated with TDN. The CO2 saturation ratio was highly correlated with the N2O saturation ratio across all sites and dates, and the CO2 saturation ratio ranged from 1.1 to 73. CH4 was always supersaturated, with saturation ratios ranging from 3.0 to 2157. Longitudinal surveys extending form headwaters to third

  12. Gas and water geochemistry of geothermal systems in Dominica, Lesser Antilles island arc

    Science.gov (United States)

    Joseph, Erouscilla P.; Fournier, Nicolas; Lindsay, Jan M.; Fischer, Tobias P.

    2011-09-01

    Four of the nine potentially active volcanoes on the island of Dominica in the Lesser Antilles volcanic island arc have associated active volcanic-hydrothermal systems. Between 2000 and 2006 the gas and thermal waters from these systems were investigated to geochemically characterise the fluids, gain insight into the temperature and equilibrium state of the underlying reservoirs, and evaluate the feasibility of monitoring geothermal features as a volcano surveillance tool in Dominica. The geothermal gases are typical of those found in arc-type settings, with N 2 excess and low amounts of He and Ar. The dry gas is dominated by CO 2 (ranging from 492 to 993 mmol/mol), and has a hydrothermal signature with hydrogen sulphide as the main sulphurous gas. The waters are predominantly acid-sulphate (SO 4 = 100-4200 mg/L, pH ≤ 4), and likely formed as a result of dilution of acidic gases in near surface oxygenated groundwater. Enrichment in both δ 18O and δD with respect to the global meteoric water line (GMWL) confirms that the waters are of primarily meteoric origin, but have been affected by evaporation processes. Quartz geothermometers gave equilibrium temperatures of 83 °C-203 °C. These temperatures contrast with the higher equilibrium temperature ranges (170 °C-350 °C) obtained for the gases using the H 2/Ar*-CH 4/CO 2 gas ratios plot, suggesting that the quartz geothermometers are affected by non-attainment of equilibrium. This may be a result of precipitation of the dissolved silica and/or dilution by relatively cold shallow aquifers of the thermal fluids. Generally, no significant variations in fluid gas chemistry of the hydrothermal systems were observed during the study period, and we propose that there were no changes in the state of volcanic activity in this period. One exception to this occurred in a feature known as the Boiling Lake, which underwent a month-long period of significant compositional, temperature and water level fluctuations ascribed to

  13. Simultaneous flow of gas and water in a damage-susceptible argillaceous rock

    Science.gov (United States)

    Nguyen, T. S.

    2011-12-01

    A research project has been initiated by the Canadian Nuclear Safety Commission (CNSC) to study the influence of gas generation and migration on the long term safety of deep geological repositories for radioactive wastes. Such facilities rely on multiple barriers to isolate and contain the wastes. Depending on the level of radioactivity of the wastes, those barriers include some or all of the following: corrosion and structurally resistant containers, low permeability seals around the emplacements rooms, galleries and shaft, and finally the host rock formations. Large quantities of gas may be generated from the degradation of the waste forms or the corrosion of the containers. The generated gas pressures, if sufficiently large, can induce cracks and microcracks in the engineered and natural barriers and affect their containment functions. The author has developed a mathematical model to simulate the above effects. The model must be calibrated and validated with laboratory and field experiments in order to provide confidence in its future use for assessing the effects of gas on the long term safety of nuclear wastes repositories. The present communication describes the model and its use in the simulation of laboratory and large scale in-situ gas injection experiments in an argillaceous rock, known as Opalinus clay, from Mont Terri, Switzerland. Both the laboratory and in-situ experiments show that the gas flow rate substantially increases when the injection pressure is higher than the confining stress. The above observation seems to indicate that at high gas injection pressures, damage could possibly be induced in the rock formation resulting in an important increase in its permeability. In order to simulate the experiments, we developed a poro-elastoplastic model, with the consideration of two compressible pore fluids (water and gas). The bulk movement of the pore fluids is assumed to obey the generalized Darcy's law, and their respective degree of saturation is

  14. State-scale perspective on water use and production associated with oil and gas operations, Oklahoma, U.S.

    Science.gov (United States)

    Murray, Kyle E

    2013-05-07

    A common goal of water and energy management is to maximize the supply of one while minimizing the use of the other, so it is important to understand the relationship between water use and energy production. A larger proportion of horizontal wells and an increasing number of hydraulically fractured well bores are being completed in the United States, and consequently increasing water demand by oil and gas operations. Management, planning, and regulatory decisions for water, oil, and gas are largely made at the state-level; therefore, it is necessary to aggregate water use and energy production data at the state-scale. The purpose of this paper is to quantify annual volumes of water used for completion of oil and gas wells, coproduced during oil and gas production, injected via underground injection program wells, and used in water flooding operations. Data from well completion reports, and tax commission records were synthesized to arrive at these estimates for Oklahoma. Hydraulic fracturing required a median fluid volume of 11,350 m(3) per horizontal well in Oklahoma. Median fluid volume (~15,774 m(3)) and volume per perforated interval (15.73 m(3) m(-1)) were highest for Woodford Shale horizontal wells. State-scale annual water use for oil and gas well completions was estimated to be up to 16.3 Mm(3) in 2011 or less than 1% of statewide freshwater use. Statewide annual produced water volumes ranged from 128.5 to 146.6 Mm(3), with gas wells yielding an estimated 72.4% of the total coproduced water. Volumes of water injected into underground injection control program wells ranged from 206.8 to 305.4 Mm(3), which indicates that water flooding operations may use up to 167.0 Mm(3) per year. State-scale water use estimates for Oklahoma could be improved by requiring oil and gas operators to supplement well completion reports with water use and water production data. Reporting of oil and gas production data by well using a unique identifier (i.e., API number) would also

  15. Impact of Pilot Light Modeling on the Predicted Annual Performance of Residential Gas Water Heaters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.

    2013-08-01

    Modeling residential water heaters with dynamic simulation models can provide accurate estimates of their annual energy consumption, if the units? characteristics and use conditions are known. Most gas storage water heaters (GSWHs) include a standing pilot light. It is generally assumed that the pilot light energy will help make up standby losses and have no impact on the predicted annual energy consumption. However, that is not always the case. The gas input rate and conversion efficiency of a pilot light for a GSWH were determined from laboratory data. The data were used in simulations of a typical GSWH with and without a pilot light, for two cases: 1) the GSWH is used alone; and 2) the GSWH is the second tank in a solar water heating (SWH) system. The sensitivity of wasted pilot light energy to annual hot water use, climate, and installation location was examined. The GSWH used alone in unconditioned space in a hot climate had a slight increase in energy consumption. The GSWH with a pilot light used as a backup to an SWH used up to 80% more auxiliary energy than one without in hot, sunny locations, from increased tank losses.

  16. Recycling of coal seam gas-associated water using vacuum membrane distillation.

    Science.gov (United States)

    Heidarpour, Farideh; Shi, Jeffrey; Chae, So-Ryong

    2015-01-01

    Coal seam gas-associated water (CSGAW), which is a by-product of coal seam gas (CSG) production typically contains significant amounts of salts and has potential environmental issues. In this study, we optimized a bench-scale vacuum membrane distillation (VMD) process with flat-sheet hydrophobic polytetrafluoroethylene (PTFE) membranes for the treatment of synthetic CSGAW (conductivity = 15 mS/cm). To study performance of the VMD process, we explored the effects of feed temperature (T(f) = 60, 70, and 80°C), feed flow rate (V(f) = 60, 120, and 240 mL/min), and vacuum pressure (P(v) = 3, 6, and 9 kPa) on water permeability through the PTFE membrane in the VMD process. Under the optimum conditions (i.e. T(f) = 80°C, V(f) = 240 mL/min, P(v) = 3 kPa), water permeability and rejection efficiency of salts by the VMD process were found to be 5.5 L/m(2)/h (LMH) and 99.9%, respectively, after 2 h filtration. However, after 8 h operation, the water permeability decreased by 70% compared with the initial flux due to the formation of fouling layer of calcium, chloride, sodium, magnesium, and potassium on the membrane surface.

  17. Recommended Ideal-Gas Thermochemical Functions for Heavy Water and its Substituent Isotopologues

    Science.gov (United States)

    Simkó, Irén; Furtenbacher, Tibor; Hrubý, Jan; Zobov, Nikolai F.; Polyansky, Oleg L.; Tennyson, Jonathan; Gamache, Robert R.; Szidarovszky, Tamás; Dénes, Nóra; Császár, Attila G.

    2017-06-01

    Accurate temperature-dependent ideal-gas internal partition functions, Qint(T), and several derived thermochemical functions are reported for heavy water, with an oxygen content corresponding to the isotopic composition of Vienna Standard Mean Ocean Water (VSMOW), and its constituent isotopologues, D216O, D217O, and D218O, for temperatures between 0 and 6000 K. The nuclear-spin-dependent partition functions are obtained by the direct summation technique, involving altogether about 16 000 measured and more than nine million computed bound rovibrational energy levels for the three molecules. Reliable standard uncertainties, as a function of temperature, are estimated for each thermochemical quantity determined, including the enthalpy, the entropy, and the isobaric heat capacity of the individual nuclear-spin-equilibrated isotopologues and of heavy water. The accuracy of the heavy-water ideal-gas Cp(T) is unprecedented, below 0.01% up to 1800 K. All the thermochemical functions are reported, in 1 K increments, in the supplementary material.

  18. Water Determination in Solid Pharmaceutical Products Utilizing Ionic Liquids and Headspace Gas Chromatography.

    Science.gov (United States)

    Frink, Lillian A; Armstrong, Daniel W

    2016-08-01

    A rapid, accurate, and precise headspace gas chromatographic (HSGC) analytical method was developed for the detection and quantification of water in drug products. The analysis is able to be performed in 10 min and automated. The HSGC method used an ionic liquid (IL) based open tubular capillary gas chromatographic column to increase the ruggedness of this method and provide improved peak shapes for water. Due to the ionic liquids low vapor pressure, unique physiochemical properties, and high thermal stability, they also make idea solvents for HSGC. Unlike Karl Fischer titration methods, this HSGC method is not affected by side reactions. The developed method was shown to be broadly applicable. The water content in 12 different samples was found to range from 1%-7% water. The use of HSGC was highly sensitive and only required 10 mg of sample. In addition, it was found to have greater precision and accuracy than Karl Fischer titration and greater precision and speed than loss on drying.

  19. Characterizing Natural Gas Hydrates in the Deep Water Gulf of Mexico: Applications for Safe Exploration and Production Activities

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Jimmy

    2014-05-31

    In 2000 Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deep water portion of the Gulf of Mexico (GOM). Chevron is an active explorer and operator in the Gulf of Mexico and is aware that natural gas hydrates need to be understood to operate safely in deep water. In August 2000 Chevron worked closely with the National Energy Technology Laboratory (NETL) of the United States Department of Energy (DOE) and held a workshop in Houston, Texas to define issues concerning the characterization of natural gas hydrate deposits. Specifically, the workshop was meant to clearly show where research, the development of new technologies, and new information sources would be of benefit to the DOE and to the oil and gas industry in defining issues and solving gas hydrate problems in deep water.

  20. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  1. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-28

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  2. The Pennsylvania Experience with Hydraulic Fracturing for Shale Gas Development: Relatively Infrequent Water Quality Incidents with Lots of Public Attention

    Science.gov (United States)

    Brantley, S. L.; Li, Z.; Yoxtheimer, D.; Vidic, R.

    2015-12-01

    New techniques of hydraulic fracturing - "fracking" - have changed the United States over the last 10 years into a leading producer of natural gas extraction from shale. The first such gas well in Pennsylvania was drilled and completed using high-volume hydraulic fracturing in 2004. By late 2014, more than 8500 of these gas wells had been drilled in the Marcellus Shale gas field in Pennsylvania alone. Almost 1000 public complaints about groundwater quality were logged by the PA Department of Environmental Protection (PA DEP) between 2008 and 2012. Only a fraction of these were attributed to unconventional gas development. The most common problem was gas migration into drinking water, but contamination incidents also included spills, seepage, or leaks of fracking fluids, brine salts, or very occasionally, radioactive species. Many problems of gas migration were from a few counties in the northeastern part of the state. However, sometimes one gas well contaminated multiple water wells. For example, one gas well was reported by the state regulator to have contaminated 18 water wells with methane near Dimock PA. It can be argued that such problems at a relatively small fraction of gas wells initiated pockets of pushback against fracking worldwide. This resistance to fracking has grown even though fracking has been in use in the U.S.A. since the 1940s. We have worked as part of an NSF-funded project (the Shale Network) to share water quality data and publish it online using the CUAHSI Hydrologic Information System. Sharing data has led to collaborative investigation of specific contamination incidents to understand how problems can occur, and to efforts to quantify the frequency of impacts. The Shale Network efforts have also highlighted the need for more transparency with water quality data in the arena related to the energy-water nexus. As more data are released, new techniques of data analysis will allow better understanding of how to tune best practices to be

  3. Radon-222 concentrations in ground water and soil gas on Indian reservations in Wisconsin

    Science.gov (United States)

    DeWild, John F.; Krohelski, James T.

    1995-01-01

    The weighted average radon-222 concentration of indoor air in homes located on Wisconsin Indian Reservations is 5.8 picocuries per liter, which exceeds the U.S. Environmental Protection Agency action limit of 4 picocuries per liter. Ground water is the principle source of drinking water on Wisconsin Indian Reservations and generally accounts for about 5 percent of the total indoor air radon-222 concentrations found in homes. To determine the distribution of radon-222, ground water from 29 private and community Wisconsin Indian Reservation wells and soil gas at a depth of about 3 feet below land surface adjacent to the wells were sampled. Sites with wells were distributed among the 11 Wisconsin Indian Reservations so that each Reservation contained at least 2 sites. The remaining seven sites were divided among the Reservation by acreage held by each tribe.

  4. WATER-GAS SHIFT KINETICS OVER IRON OXIDE CATALYSTS AT MEMBRANE REACTOR CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Carl R.F. Lund

    2002-08-02

    The kinetics of water-gas shift were studied over ferrochrome catalysts under conditions with high carbon dioxide partial pressures, such as would be expected in a membrane reactor. The catalyst activity is inhibited by increasing carbon dioxide partial pressure. A microkinetic model of the reaction kinetics was developed. The model indicated that catalyst performance could be improved by decreasing the strength of surface oxygen bonds. Literature data indicated that adding either ceria or copper to the catalyst as a promoter might impart this desired effect. Ceria-promoted ferrochrome catalysts did not perform any better than unpromoted catalyst at the conditions tested, but copper-promoted ferrochrome catalysts did offer an improvement over the base ferrochrome material. A different class of water-gas shift catalyst, sulfided CoMo/Al{sub 2}O{sub 3} is not affected by carbon dioxide and may be a good alternative to the ferrochrome system, provided other constraints, notably the requisite sulfur level and maximum temperature, are not too limiting. A model was developed for an adiabatic, high-temperature water-gas shift membrane reactor. Simulation results indicate that an excess of steam in the feed (three moles of water per mole of CO) is beneficial even in a membrane reactor as it reduces the rate of adiabatic temperature rise. The simulations also indicate that much greater improvement can be attained by improving the catalyst as opposed to improving the membrane. Further, eliminating the inhibition by carbon dioxide will have a greater impact than will increasing the catalyst activity (assuming inhibition is still operative). Follow-up research into the use of sulfide catalysts with continued kinetic and reactor modeling is suggested.

  5. Existence for a global pressure formulation of water-gas flow in porous media

    Directory of Open Access Journals (Sweden)

    Brahim Amaziane

    2012-06-01

    Full Text Available We consider a model of water-gas flow in porous media with an incompressible water phase and a compressible gas phase. Such models appear in gas migration through engineered and geological barriers for a deep repository for radioactive waste. The main feature of this model is the introduction of a new global pressure and it is fully equivalent to the original equations. The system is written in a fractional flow formulation as a degenerate parabolic system with the global pressure and the saturation potential as the main unknowns. The major difficulties related to this model are in the nonlinear degenerate structure of the equations, as well as in the coupling in the system. Under some realistic assumptions on the data, including unbounded capillary pressure function and non-homogeneous boundary conditions, we prove the existence of weak solutions of the system. Furthermore, it is shown that the weak solution has certain desired properties, such as positivity of the saturation. The result is proved with the help of an appropriate regularization and a time discretization of the coupled system. We use suitable test functions to obtain a priori estimates and a compactness result in order to pass to the limit in nonlinear terms.

  6. LASER TRIGGERED GAS SWITCHES UTILIZING BEAM TRANSPORT THROUGH 1 MO-cm DEIONIZED WATER.

    Energy Technology Data Exchange (ETDEWEB)

    Woodworth, Joseph Ray; Lehr, Jane [Sandia National Laboratories, Albuquerque, NM; Blickem, James R.; Wallace, Zachariah R.; Anaya, Victor Jr; Corley, John P; Lott, John; Hodge, Keith; Zameroski, Nathan D. [Sandia National Laboratories, Albuquerque, NM

    2005-11-01

    We report on the successful attempts to trigger high voltage pressurized gas switches by utilizing beam transport through 1 MO-cm deionized water. The wavelength of the laser radiation was 532 nm. We have investigated Nd: YAG laser triggering of a 6 MV, SF6 insulated gas switch for a range of laser and switch parameters. Laser wavelength of 532 nm with nominal pulse lengths of 10 ns full width half maximum (FWHM) were used to trigger the switch. The laser beam was transported through 67 cm-long cell of 1 MO-cm deionized water constructed with anti reflection UV grade fused silica windows. The laser beam was then focused to form a breakdown arc in the gas between switch electrodes. Less than 10 ns jitter in the operation of the switch was obtained for laser pulse energies of between 80-110 mJ. Breakdown arcs more than 35 mm-long were produced by using a 70 cm focusing optic.

  7. Effect of biochar on soil structural characteristics: water retention and gas transport

    DEFF Research Database (Denmark)

    Sun, Zhencai; Møldrup, Per; Vendelboe, Anders Lindblad

    -gas diffusivity on intact 100cm3 soil samples (5 replicates in each plot). We found that biochar application significantly decreased soil bulk density, hereby creating higher porosity. At the same soil-water matric potential, all the soil-gas phase parameters (air-filled porosity, air permeability and gas...... and B plots were placed in a mixed sequence (C-B-C-B-C-B-C-B) and at the same time the eight plots formed a natural pH gradient ranging from pH 7.7 to 6.3. We determined bulk density, saturated hydraulic conductivity (K-sat), soil water retention characteristics, soil-air permeability, and soil...... due to the high micro porosity of added biochar. In conclusion, the results showed that biochar addition to soil changed key soil structural parameters at least in the short term (1 year). In perspective, the long-term variations in soil structural parameters and related changed in microbial activity...

  8. Plasma Discharges in Gas Bubbles in Liquid Water: Breakdown Mechanisms and Resultant Chemistry

    Science.gov (United States)

    Gucker, Sarah M. N.

    The use of atmospheric pressure plasmas in gases and liquids for purification of liquids has been investigated by numerous researchers, and is highly attractive due to their strong potential as a disinfectant and sterilizer. However, the fundamental understanding of plasma production in liquid water is still limited. Despite the decades of study dedicated to electrical discharges in liquids, many physical aspects of liquids, such as the high inhomogeneity of liquids, complicate analyses. For example, the complex nonlinearities of the fluid have intricate effects on the electric field of the propagating streamer. Additionally, the liquid material itself can vaporize, leading to discontinuous liquid-vapor boundaries. Both can and do often lead to notable hydrodynamic effects. The chemistry of these high voltage discharges on liquid media can have circular effects, with the produced species having influence on future discharges. Two notable examples include an increase in liquid conductivity via charged species production, which affects the discharge. A second, more complicated scenario seen in some liquids (such as water) is the doubling or tripling of molecular density for a few molecule layers around a high voltage electrode. These complexities require technological advancements in optical diagnostics that have only recently come into being. This dissertation investigates several aspects of electrical discharges in gas bubbles in liquids. Two primary experimental configurations are investigated: the first allows for single bubble analysis through the use of an acoustic trap. Electrodes may be brought in around the bubble to allow for plasma formation without physically touching the bubble. The second experiment investigates the resulting liquid phase chemistry that is driven by the discharge. This is done through a dielectric barrier discharge with a central high voltage surrounded by a quartz discharge tube with a coil ground electrode on the outside. The plasma

  9. Model-Based Design of Energy Efficient Palladium Membrane Water Gas Shift Fuel Processors for PEM Fuel Cell Power Plants

    Science.gov (United States)

    Gummalla, Mallika; Vanderspurt, Thomas Henry; Emerson, Sean; She, Ying; Dardas, Zissis; Olsommer, Benoît

    An integrated, palladium alloy membrane Water-Gas Shift (WGS) reactor can significantly reduce the size, cost and complexity of a fuel processor for a Polymer Electrolyte Membrane fuel cell power system.

  10. Method 349.0 Determination of Ammonia in Estuarine and Coastal Waters by Gas Segmented Continuous Flow Colorimetric Analysis

    Science.gov (United States)

    This method provides a procedure for the determination of ammonia in estuarine and coastal waters. The method is based upon the indophenol reaction,1-5 here adapted to automated gas-segmented continuous flow analysis.

  11. Experimental check of possibility of research of repeated inclusion of the open gas generator in the water environment

    Directory of Open Access Journals (Sweden)

    Goldaev Sergey

    2017-01-01

    Full Text Available Experimental study of repeated burning interruption with the subsequent ignition in the water environment for bibasic firm fuel as a part of a model open solid propellant gas generator is presented. Video filming of burning zone mobile localizer providing process of repeated inclusion of a gas generator are given. Some parameters of the processes proceeding in these conditions are defined

  12. Fluorometric, water-based sensors for the detection of nerve gas G mimics DMMP, DCP and DCNP.

    Science.gov (United States)

    Wild, Andreas; Winter, Andreas; Hager, Martin D; Schubert, Ulrich S

    2012-01-25

    Water-based Zn(II) bisterpyridine systems were used as fluorometric sensors for the detection of the nerve gas G mimics DMMP, DCP and DCNP. Analyte concentrations in the range of 10(-7) to 10(-6) M are detectable in solution. The utilization of a test stripe additionally allows the detection of organophosphonates from the gas phase.

  13. Inelastic scattering in ocean water and its impact on trace gas retrievals from satellite data

    Directory of Open Access Journals (Sweden)

    M. Vountas

    2003-01-01

    Full Text Available Over clear ocean waters, photons scattered within the water body contribute significantly to the upwelling flux. In addition to elastic scattering, inelastic Vibrational Raman Scattering (VRS by liquid water is also playing a role and can have a strong impact on the spectral distribution of the outgoing radiance. Under clear-sky conditions, VRS has an influence on trace gas retrievals from space-borne measurements of the backscattered radiance such as from e.g. GOME (Global Ozone Monitoring Experiment. The effect is particularly important for geo-locations with small solar zenith angles and over waters with low chlorophyll concentration. In this study, a simple ocean reflectance model (Sathyendranath and Platt, 1998 accounting for VRS has been incorporated into a radiative transfer model. The model has been validated by comparison with measurements from a swimming-pool experiment dedicated to detect the effect of scattering within water on the outgoing radiation and also with selected data sets from GOME. The comparisons show good agreement between experimental and model data and highlight the important role of VRS. To evaluate the impact of VRS on trace gas retrieval, a sensitivity study was performed on synthetic data. If VRS is neglected in the data analysis, errors of more than 30% are introduced for the slant column (SC of BrO over clear ocean scenarios. Exemplarily DOAS retrievals of BrO from real GOME measurements including and excluding a VRS compensation led to comparable results as in the sensitivity study, but with somewhat smaller differences between the two analyses. The results of this work suggest, that DOAS retrievals of atmospheric trace species from measurements of nadir viewing space-borne instruments have to take VRS scattering into account over waters with low chlorophyll concentrations, and that a simple correction term is enough to reduce the errors to an acceptable level.

  14. Nitrogen removal and greenhouse gas emissions from constructed wetlands receiving tile drainage water.

    Science.gov (United States)

    Groh, Tyler A; Gentry, Lowell E; David, Mark B

    2015-05-01

    Loss of nitrate from agricultural lands to surface waters is an important issue, especially in areas that are extensively tile drained. To reduce these losses, a wide range of in-field and edge-of-field practices have been proposed, including constructed wetlands. We re-evaluated constructed wetlands established in 1994 that were previously studied for their effectiveness in removing nitrate from tile drainage water. Along with this re-evaluation, we measured the production and flux of greenhouse gases (GHGs) (CO, NO, and CH). The tile inlets and outlets of two wetlands were monitored for flow and N during the 2012 and 2013 water years. In addition, seepage rates of water and nitrate under the berm and through the riparian buffer strip were measured. Greenhouse gas emissions from the wetlands were measured using floating chambers (inundated fluxes) or static chambers (terrestrial fluxes). During this 2-yr study, the wetlands removed 56% of the total inlet nitrate load, likely through denitrification in the wetland. Some additional removal of nitrate occurred in seepage water by the riparian buffer strip along each berm (6.1% of the total inlet load, for a total nitrate removal of 62%). The dominant GHG emitted from the wetlands was CO, which represented 75 and 96% of the total GHG emissions during the two water years. The flux of NO contributed between 3.7 and 13% of the total cumulative GHG flux. Emissions of NO were 3.2 and 1.3% of the total nitrate removed from wetlands A and B, respectively. These wetlands continue to remove nitrate at rates similar to those measured after construction, with relatively little GHG gas loss. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

    Science.gov (United States)

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

    1965-01-01

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

  16. Purge efficiency in the determination of trihalomethanes in water by purge-and-trap gas chromatography.

    Science.gov (United States)

    Ruiz-Bevia, Francisco; Fernandez-Torres, Maria J; Blasco-Alemany, Maria P

    2009-01-26

    Purge-and-trap gas chromatography-mass spectrometry (PT-GC-MS) has become an accepted method for the analysis of trihalomethanes (THMs) in water. The purge-and-trap technique is based on an efficient transfer of volatile organic compounds from the liquid (contained in the purge chamber) to the gaseous phase by bubbling with an inert gas. The aim of this work was to study the purge system's efficiency by means of several consecutive purge cycles lasting 11 min each of the same liquid sample. The concentration range chosen of THMs was very wide [5-200 microg L(-1)]. The inert gas flow rate was 40 mL min(-1), and experiments were performed at temperatures of 25, 35 and 50 degrees C. Bromoform (CHBr(3)), the least volatile compound, needed 19 cycles to be purged quantitatively at a concentration of 200 microg L(-1) and only 7 cycles at 5 microg L(-1) for a 25 mL sample at 25 degrees C. Chloroform (CHCl(3)), the most volatile compound, required 4 cycles to be fully extracted at 200 microg L(-1) and 2 at 5 microg L(-1). Finally, Novak's theoretical model, based on the distribution constant between gas and liquid phases, was used to correlate the THMs purging extraction data.

  17. Ground-water quality of the Upper Floridan Aquifer near an abandoned manufactured gas plant in Albany, Georgia

    Science.gov (United States)

    Chapman, M.J.

    1993-01-01

    Manufactured gas plants produced gas for heating and lighting in the United States from as early as 1816 into the 1960's. By-products including, but not limited to, oil residues and tar, were generated during the gas-manufacturing process. Organic compounds (hydrocarbons) were detected in water in the upper water-bearing zone of the Upper Floridan aquifer near an abandoned manufactured gas plant (MGP) in Albany, Georgia, during an earlier investigation in 1990. Chemical analyses of ground-water samples collected from five existing monitoring wells in 1991 verify the presence of hydrocarbons and metals in the upper water-beating zone of the Upper Floridan aquifer. One well was drilled into the lower water-beating zone of the Upper Floridan aquifer in 1991 for water-quality sampling and water-level monitoring. Analyses of ground water sampled from this well did not show evidence of benzene, toluene, xylene, napthalene, acenaphthlene, or other related compounds detected in the upper water-bearing zone in the study area. Low concentrations of tetrachloroethane, trichloromethane, and l,2-cisdichloroethene were detected in a water sample from the deeper well; however, these compounds were not detected in the upper water-bearing zone in the study area. Inorganic constituent concentrations also were substantially lower in the deeper well. Overall, ground water sampled from the lower water-bearing zone had lower specific conductance and alkalinity; and lower concentrations of dissolved solids, iron, and manganese compared to ground water sampled from the upper water-bearing zone. Water levels for the upper and lower water-bearing zones were similar throughout the study period.

  18. Water acquisition and use during unconventional oil and gas development and the existing data challenges: Weld and Garfield counties, CO.

    Science.gov (United States)

    Oikonomou, Panagiotis D; Kallenberger, Julie A; Waskom, Reagan M; Boone, Karie K; Plombon, Elizabeth N; Ryan, Joseph N

    2016-10-01

    Colorado has recently experienced a significant increase in unconventional oil and gas development, with the greatest concentration of activity occurring in Weld and Garfield counties. Water for oil and gas development has received much attention mainly because water resources are limited in these regions and development is taking place closer to populated areas than it did in the past. Publicly available datasets for the period 2011-2014 were used to identify water acquisition strategies and sources of water used for oil and gas. In addition, the annual average water used in these two counties was quantified and compared to their total water withdrawals. The analysis also quantified the water needed for different well types, along with the flowback water that is retrieved. Weld and Garfield counties are dissimilar in respect to development practices for water acquisition, preferred well type and the fate of flowback water. But at the same time, this difference displays how geological characteristics, water availability, and administration localities are the key elements along with economics in the decision making process within the oil and gas sector. This effort also revealed data challenges regarding accessibility and reliability of reported information, and the need for additional data. Improving the understanding of the unconventional oil and gas sector's water use will help identify possible effects and tradeoffs on the local/regional level, which could diminish the conflicting perspectives that shape the water-energy discussions. This would complement the ability to make informed water resources planning and management decisions that are environmentally and socially acceptable.

  19. Surface waters as a sink and source of atmospheric gas phase ethanol.

    Science.gov (United States)

    Avery, G Brooks; Foley, Laura; Carroll, Angela L; Roebuck, Jesse Alan; Guy, Amanda; Mead, Ralph N; Kieber, Robert J; Willey, Joan D; Skrabal, Stephen A; Felix, J David; Mullaugh, Katherine M; Helms, John R

    2016-02-01

    This study reports the first ethanol concentrations in fresh and estuarine waters and greatly expands the current data set for coastal ocean waters. Concentrations for 153 individual measurements of 11 freshwater sites ranged from 5 to 598 nM. Concentrations obtained for one estuarine transect ranged from 56 to 77 nM and levels in five coastal ocean depth profiles ranged from 81 to 334 nM. Variability in ethanol concentrations was high and appears to be driven primarily by photochemical and biological processes. 47 gas phase concentrations of ethanol were also obtained during this study to determine the surface water degree of saturation with respect to the atmosphere. Generally fresh and estuarine waters were undersaturated indicating they are not a source and may be a net sink for atmospheric ethanol in this region. Aqueous phase ethanol is likely converted rapidly to acetaldehyde in these aquatic ecosystems creating the undersaturated conditions resulting in this previously unrecognized sink for atmospheric ethanol. Coastal ocean waters may act as either a sink or source of atmospheric ethanol depending on the partial pressure of ethanol in the overlying air mass. Results from this study are significant because they suggest that surface waters may act as an important vector for the uptake of ethanol emitted into the atmosphere including ethanol from biofuel production and usage.

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

    Science.gov (United States)

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

    1990-01-01

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

  1. Automatic carbon dioxide-methane gas sensor based on the solubility of gases in water.

    Science.gov (United States)

    Cadena-Pereda, Raúl O; Rivera-Muñoz, Eric M; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J; Anaya-Rivera, Ely K

    2012-01-01

    Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0-100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

  2. Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

    Directory of Open Access Journals (Sweden)

    Raúl O. Cadena-Pereda

    2012-08-01

    Full Text Available Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0–100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

  3. Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder

    Directory of Open Access Journals (Sweden)

    Ali B.

    2017-06-01

    Full Text Available The water atomization of iron powder with a composition of Fe-3Cr-0.5Mo (wt.% at 1600°C and 150 bar creates an oxide layer, which in this study was reduced using a mixture of methane (CH4 and argon (Ar gas. The lowest oxygen content was achieved with a 100 cc/min flow rate of CH4, but this also resulted in a co-deposition of carbon due to the cracking of CH4. This carbon can be used directly to create high-quality, sinter hardenable steel, thereby eliminating the need for an additional mixing step prior to sintering. An exponential relationship was found to exist between the CH4 gas flow rate and carbon content of the powder, meaning that its composition can be easily controlled to suit a variety of different applications.

  4. Supercritical water gasification of sewage sludge: gas production and phosphorus recovery.

    Science.gov (United States)

    Acelas, Nancy Y; López, Diana P; Brilman, D W F Wim; Kersten, Sascha R A; Kootstra, A Maarten J

    2014-12-01

    In this study, the feasibility of the gasification of dewatered sewage sludge in supercritical water (SCW) for energy recovery combined with P-recovery from the solid residue generated in this process was investigated. SCWG temperature (400°C, 500°C, 600°C) and residence time (15min, 30min, 60min) were varied to investigate their effects on gas production and the P recovery by acid leaching. The results show that the dry gas composition for this uncatalyzed gasification of sewage sludge in SCW mainly comprised of CO2, CO, CH4, H2, and some C2-C3 compounds. Higher temperatures and longer residence times favored the production of H2 and CH4. After SCWG, more than 95% of the P could be recovered from the solid residue by leaching with acids. SCWG combined with acid leaching seems an effective method for both energy recovery and high P recovery from sewage sludge.

  5. Thermodynamic Consistency Test for Binary Gas+Water Equilibrium Data at Low and High Pressures

    Institute of Scientific and Technical Information of China (English)

    Claudio A. Fandez; Felipe A. Quiero; Jos O. Valderrama

    2013-01-01

    Phase equilibrium in binary gas+water mixtures over wide ranges of temperatures and pressures are modeled and tested for thermodynamic consistency. For modeling, the Peng-Robinson equation of state was used and the Wong-Sandler mixing rules were incorporated into the equation of state parameters. In the Wong-Sandler mixing rules the van Laar model for the excess Gibbs en-ergy was applied. In addition, a reasonable and flexible method is applied to test the thermody-namic consistency of pressure-temperature-concentration (P-T-x) data of these binary mixtures. Modeling is found acceptable in all cases, meaning that deviations in correlating the pressure and the gas phase concentration are low. For all cases the thermodynamic consistency method gives a clear conclusion about consistency or inconsistency of a set of experimental P-T-x data.

  6. Study of activity and effectiveness factor of noble metal catalysts for water-gas shift reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sungkwang; Bae, Joongmyeon [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-Dong, Yuseong-Gu, Daejeon 305-701 (Korea); Kim, Kihyun [POSCO 1, Goedong-dong, Nam-gu, Pohang, Gyeongbuk 790-785 (Korea)

    2009-01-15

    Platinum on ceria-zirconia (CZO) catalysts for the water-gas shift (WGS) reaction were prepared with various platinum loadings. In addition, the activity of Pt/CZO catalysts was tested preliminarily at gas hourly space velocity (GHSV) of 5000 h{sup -1}. Activity tests were also conducted at GHSV of 200,000 h{sup -1} with limited conversions, and activation energies and pre-exponential factors for rate equations were obtained by fitting the data. The effectiveness factors were estimated on the basis of the intra-particle mass transfer. Moreover, with this estimation, an attempt was made to calculate the utilization of the Pt loading with an eggshell morphology. (author)

  7. Protein structural dynamics at the gas/water interface examined by hydrogen exchange mass spectrometry.

    Science.gov (United States)

    Xiao, Yiming; Konermann, Lars

    2015-08-01

    Gas/water interfaces (such as air bubbles or foam) are detrimental to the stability of proteins, often causing aggregation. This represents a potential problem for industrial processes, for example, the production and handling of protein drugs. Proteins possess surfactant-like properties, resulting in a high affinity for gas/water interfaces. The tendency of previously buried nonpolar residues to maximize contact with the gas phase can cause significant structural distortion. Most earlier studies in this area employed spectroscopic tools that could only provide limited information. Here we use hydrogen/deuterium exchange (HDX) mass spectrometry (MS) for probing the conformational dynamics of the model protein myoglobin (Mb) in the presence of N(2) bubbles. HDX/MS relies on the principle that unfolded and/or highly dynamic regions undergo faster deuteration than tightly folded segments. In bubble-free solution Mb displays EX2 behavior, reflecting the occurrence of short-lived excursions to partially unfolded conformers. A dramatically different behavior is seen in the presence of N(2) bubbles; EX2 dynamics still take place, but in addition the protein shows EX1 behavior. The latter results from interconversion of the native state with conformers that are globally unfolded and long-lived. These unfolded species likely correspond to Mb that is adsorbed to the surface of gas bubbles. N(2) sparging also induces aggregation. To explain the observed behavior we propose a simple model, that is, "semi-unfolded" ↔ "native" ↔ "globally unfolded" → "aggregated". This model quantitatively reproduces the experimentally observed kinetics. To the best of our knowledge, the current study marks the first exploration of surface denaturation phenomena by HDX/MS.

  8. Omniphobic Polyvinylidene Fluoride (PVDF) Membrane for Desalination of Shale Gas Produced Water by Membrane Distillation.

    Science.gov (United States)

    Boo, Chanhee; Lee, Jongho; Elimelech, Menachem

    2016-11-15

    Microporous membranes fabricated from hydrophobic polymers such as polyvinylidene fluoride (PVDF) have been widely used for membrane distillation (MD). However, hydrophobic MD membranes are prone to wetting by low surface tension substances, thereby limiting their use in treating challenging industrial wastewaters, such as shale gas produced water. In this study, we present a facile and scalable approach for the fabrication of omniphobic polyvinylidene fluoride (PVDF) membranes that repel both water and oil. Positive surface charge was imparted to an alkaline-treated PVDF membrane by aminosilane functionalization, which enabled irreversible binding of negatively charged silica nanoparticles (SiNPs) to the membrane through electrostatic attraction. The membrane with grafted SiNPs was then coated with fluoroalkylsilane (perfluorodecyltrichlorosilane) to lower the membrane surface energy. Results from contact angle measurements with mineral oil and surfactant solution demonstrated that overlaying SiNPs with ultralow surface energy significantly enhanced the wetting resistance of the membrane against low surface tension liquids. We also evaluated desalination performance of the modified membrane in direct contact membrane distillation with a synthetic wastewater containing surfactant (sodium dodecyl sulfate) and mineral oil, as well as with shale gas produced water. The omniphobic membrane exhibited a stable MD performance, demonstrating its potential application for desalination of challenging industrial wastewaters containing diverse low surface tension contaminants.

  9. Experimental Study on the Absorption of Toluene from Exhaust Gas by Paraffin/Surfactant/Water Emulsion

    Directory of Open Access Journals (Sweden)

    Ping Fang

    2016-01-01

    Full Text Available A new paraffin/surfactant/water emulsion (PSW for volatile organic compounds (VOCs controlling was prepared and its potential for VOCs removal was investigated. Results indicated that PSW-5 (5%, v/v provided higher toluene absorption efficiency (90.77% than the other absorbents used. The saturation pressure, Henry’s constant, and activity coefficient of toluene in PSW-5 were significantly lower than those in water, and toluene solubility (1.331 g·L−1 in the PSW-5 was more than 2.5 times higher than the value in water. Several factors potentially affecting the toluene absorption efficiency were systematically investigated. The results suggested that concentration and pH of PSW, absorption temperature, and gas flow rate all had a strong influence on the toluene absorption, but the inlet concentration of toluene had little effect on the toluene absorption. There were different absorbing performances of PSW-5 on different VOCs, and the ketones, esters, and aromatics were more easily removed by the PSW-5 than the alkanes. Regeneration and reuse of the PSW were possible; after 3 runs of regeneration the absorption efficiency of PSW-5 for toluene also could reach 82.42%. So, the PSW is an economic, efficient, and safe absorbent and has a great prospect in organic waste gas treatment.

  10. U.S. Geological Survey Noble Gas Laboratory’s standard operating procedures for the measurement of dissolved gas in water samples

    Science.gov (United States)

    Hunt, Andrew G.

    2015-08-12

    This report addresses the standard operating procedures used by the U.S. Geological Survey’s Noble Gas Laboratory in Denver, Colorado, U.S.A., for the measurement of dissolved gases (methane, nitrogen, oxygen, and carbon dioxide) and noble gas isotopes (helium-3, helium-4, neon-20, neon-21, neon-22, argon-36, argon-38, argon-40, kryton-84, krypton-86, xenon-103, and xenon-132) dissolved in water. A synopsis of the instrumentation used, procedures followed, calibration practices, standards used, and a quality assurance and quality control program is presented. The report outlines the day-to-day operation of the Residual Gas Analyzer Model 200, Mass Analyzer Products Model 215–50, and ultralow vacuum extraction line along with the sample handling procedures, noble gas extraction and purification, instrument measurement procedures, instrumental data acquisition, and calculations for the conversion of raw data from the mass spectrometer into noble gas concentrations per unit mass of water analyzed. Techniques for the preparation of artificial dissolved gas standards are detailed and coupled to a quality assurance and quality control program to present the accuracy of the procedures used in the laboratory.

  11. The Integration of a Structural Water Gas Shift Catalyst with a Vanadium Alloy Hydrogen Transport Device

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Thomas; Argyle, Morris; Popa, Tiberiu

    2009-06-30

    This project is in response to a requirement for a system that combines water gas shift technology with separation technology for coal derived synthesis gas. The justification of such a system would be improved efficiency for the overall hydrogen production. By removing hydrogen from the synthesis gas stream, the water gas shift equilibrium would force more carbon monoxide to carbon dioxide and maximize the total hydrogen produced. Additional benefit would derive from the reduction in capital cost of plant by the removal of one step in the process by integrating water gas shift with the membrane separation device. The answer turns out to be that the integration of hydrogen separation and water gas shift catalysis is possible and desirable. There are no significant roadblocks to that combination of technologies. The problem becomes one of design and selection of materials to optimize, or at least maximize performance of the two integrated steps. A goal of the project was to investigate the effects of alloying elements on the performance of vanadium membranes with respect to hydrogen flux and fabricability. Vanadium was chosen as a compromise between performance and cost. It is clear that the vanadium alloys for this application can be produced, but the approach is not simple and the results inconsistent. For any future contracts, large single batches of alloy would be obtained and rolled with larger facilities to produce the most consistent thin foils possible. Brazing was identified as a very likely choice for sealing the membranes to structural components. As alloying was beneficial to hydrogen transport, it became important to identify where those alloying elements might be detrimental to brazing. Cataloging positive and negative alloying effects was a significant portion of the initial project work on vanadium alloying. A water gas shift catalyst with ceramic like structural characteristics was the second large goal of the project. Alumina was added as a

  12. The Integration of a Structural Water Gas Shift Catalyst with a Vanadium Alloy Hydrogen Transport Device

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Thomas; Argyle, Morris; Popa, Tiberiu

    2009-06-30

    This project is in response to a requirement for a system that combines water gas shift technology with separation technology for coal derived synthesis gas. The justification of such a system would be improved efficiency for the overall hydrogen production. By removing hydrogen from the synthesis gas stream, the water gas shift equilibrium would force more carbon monoxide to carbon dioxide and maximize the total hydrogen produced. Additional benefit would derive from the reduction in capital cost of plant by the removal of one step in the process by integrating water gas shift with the membrane separation device. The answer turns out to be that the integration of hydrogen separation and water gas shift catalysis is possible and desirable. There are no significant roadblocks to that combination of technologies. The problem becomes one of design and selection of materials to optimize, or at least maximize performance of the two integrated steps. A goal of the project was to investigate the effects of alloying elements on the performance of vanadium membranes with respect to hydrogen flux and fabricability. Vanadium was chosen as a compromise between performance and cost. It is clear that the vanadium alloys for this application can be produced, but the approach is not simple and the results inconsistent. For any future contracts, large single batches of alloy would be obtained and rolled with larger facilities to produce the most consistent thin foils possible. Brazing was identified as a very likely choice for sealing the membranes to structural components. As alloying was beneficial to hydrogen transport, it became important to identify where those alloying elements might be detrimental to brazing. Cataloging positive and negative alloying effects was a significant portion of the initial project work on vanadium alloying. A water gas shift catalyst with ceramic like structural characteristics was the second large goal of the project. Alumina was added as a

  13. Experimental Investigation of Gas Hydrate Production at Injection of Liquid Nitrogen into Water with Bubbles of Freon 134A

    Directory of Open Access Journals (Sweden)

    Meleshkin Anton V.

    2016-01-01

    Full Text Available The hydrodynamic processes during the injection of the cryogenic liquid into the volume of water with bubbles of gas freon 134a are studding experimentally. A processes during the explosive boiling of liquid nitrogen in the volume of water are registered. Video recording of identified gas hydrate flakes formed during this process is carried out by high speed camera. These results may be useful for the study of the new method of producing gas hydrates, based on the shock-wave method.

  14. Optimal water resources management and system benefit for the Marcellus shale-gas reservoir in Pennsylvania and West Virginia

    Science.gov (United States)

    Cheng, Xi; He, Li; Lu, Hongwei; Chen, Yizhong; Ren, Lixia

    2016-09-01

    A major concern associated with current shale-gas extraction is high consumption of water resources. However, decision-making problems regarding water consumption and shale-gas extraction have not yet been solved through systematic approaches. This study develops a new bilevel optimization problem based on goals at two different levels: minimization of water demands at the lower level and maximization of system benefit at the upper level. The model is used to solve a real-world case across Pennsylvania and West Virginia. Results show that surface water would be the largest contributor to gas production (with over 80.00% from 2015 to 2030) and groundwater occupies for the least proportion (with less than 2.00% from 2015 to 2030) in both districts over the planning span. Comparative analysis between the proposed model and conventional single-level models indicates that the bilevel model could provide coordinated schemes to comprehensively attain the goals from both water resources authorities and energy sectors. Sensitivity analysis shows that the change of water use of per unit gas production (WU) has significant effects upon system benefit, gas production and pollutants (i.e., barium, chloride and bromide) discharge, but not significantly changes water demands.

  15. Evaporative cooling of microscopic water droplets in vacuo: Molecular dynamics simulations and kinetic gas theory.

    Science.gov (United States)

    Schlesinger, Daniel; Sellberg, Jonas A; Nilsson, Anders; Pettersson, Lars G M

    2016-03-28

    In the present study, we investigate the process of evaporative cooling of nanometer-sized droplets in vacuum using molecular dynamics simulations with the TIP4P/2005 water model. The results are compared to the temperature evolution calculated from the Knudsen theory of evaporation which is derived from kinetic gas theory. The calculated and simulation results are found to be in very good agreement for an evaporation coefficient equal to unity. Our results are of interest to experiments utilizing droplet dispensers as well as to cloud micro-physics.

  16. Water droplet deformation under the motion in gas area with subsonic velocities

    Directory of Open Access Journals (Sweden)

    Kuibin Pavel A.

    2015-01-01

    Full Text Available The experimental investigation of water droplet deformation (characteristic dimensions 3 ÷ 6 mm when moving through the gas area (air with 1÷ 5 m/s velocities was carried out. The high-speed (delay time between the frames is less than 100 ns tools of cross-correlation videorecording were used. A cyclic change nature of the droplet shapes (from close to spherical to conditionally ellipsoidal was found. The characteristic times of “deformation cycles” and the maximal deviations of droplet dimensions relative to initial dimensions were determined. The influence of droplet velocities and its dimensions on the deformation characteristics was determined.

  17. Electrochemical Synthesis of Mo2C Catalytical Coatings for the Water-Gas Shift Reaction

    Science.gov (United States)

    Kuznetsov, Sergey A.; Dubrovskiy, Anton R.; Rebrov, Evgeny V.; Schouten, Jaap C.

    2007-11-01

    The electroreduction of CO32- ions on a molybdenum cathode in a NaCl-KCl-Li2CO3 melt was studied by cyclic voltammetry. The electrochemical synthesis of Mo2C on molybdenum substrates has been performed at 1123 K for 7 h with a cathodic current density of 5 mA cm-2. If molybdenum carbide is present as a thin (ca. 500 nm) film on a molybdenum substrate (Mo2C/Mo), its catalytic activity in the water gas-shift reaction is enhanced by at least an order of magnitude compared to that of the bulk Mo2C phase.

  18. Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water.

    Science.gov (United States)

    Buczkowska-Radlińska, J; Łagocka, R; Kaczmarek, W; Górski, M; Nowicka, A

    2013-03-01

    The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water. The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated. Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite. The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components. To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.

  19. Application of energy and exergy analysis to increase efficiency of a hot water gas fired boiler

    Directory of Open Access Journals (Sweden)

    Todorović Milena N.

    2014-01-01

    Full Text Available In engineering practice exergy can be used for technical and economic optimization of energy conversion processes. The problem of increasing energy consumption suggests that heating plants, i.e. hot water boilers, as energy suppliers for household heating should be subjected to exergy and energy analysis. Heating plants are typically designed to meet energy demands, without the distinguished difference between quality and quantity of the produced heat. In this paper, the energy and exergy analysis of a gas fired hot water boiler is conducted. Energy analysis gives only quantitative results, while exergy analysis provides an insight into the actually available useful energy with respect to the system environment. In this paper, a hot water boiler was decomposed into control volumes with respect to its functional components. Energy and exergy of the created physical model of the hot water boiler is performed and destruction of exergy and energy loss in each of the components is calculated. The paper describes the current state of energy and exergy efficiency of the hot water boiler. The obtained results are analyzed and used to investigate possibilities for improvement of availability and reliability of the boiler. A comparison between the actual and the proposed more reliable solution is made.

  20. Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

    Science.gov (United States)

    Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

    2016-09-30

    A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well.

  1. Technical Note: Drifting vs. anchored flux chambers for measuring greenhouse gas emissions from running waters

    Directory of Open Access Journals (Sweden)

    A. Lorke

    2015-09-01

    Full Text Available Stream networks were recently discovered as major but poorly constrained natural greenhouse gas (GHG sources. A fundamental problem is that several measurement approaches have been used without cross comparisons. Flux chambers represent a potentially powerful methodological approach if robust and reliable ways to use chambers on running water can be defined. Here we compare the use of anchored and freely drifting chambers on various streams having different flow velocities. The study clearly shows that (1 drifting chambers have a very small impact on the water turbulence under the chamber and thus generate more reliable fluxes, (2 anchored chambers enhance turbulence under the chambers and thus elevate fluxes, (3 the bias of the anchored chambers greatly depends on chamber design and sampling conditions, and (4 there is a promising method to reduce the bias from anchored chambers by using a flexible plastic foil seal to the water surface rather than having rigid chamber walls penetrating into the water. Altogether, these results provide novel guidance on how to apply flux chambers in running water, which will have important consequences for measurements to constrain the global GHG balances.

  2. Evaluation of the potentials of humic acid removal in water by gas phase surface discharge plasma.

    Science.gov (United States)

    Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Yan, Qiuhe; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

    2016-02-01

    Degradation of humic acid (HA), a predominant type of natural organic matter in ground water and surface waters, was conducted using a gas phase surface discharge plasma system. HA standard and two surface waters (Wetland, and Weihe River) were selected as the targets. The experimental results showed that about 90.9% of standard HA was smoothly removed within 40 min's discharge plasma treatment at discharge voltage 23.0 kV, and the removal process fitted the first-order kinetic model. Roles of some active species in HA removal were studied by evaluating the effects of solution pH and OH radical scavenger; and the results presented that O3 and OH radical played significant roles in HA removal. Scanning electron microscope (SEM) and FTIR analysis showed that HA surface topography and molecular structure were changed during discharge plasma process. The mineralization of HA was analyzed by UV-Vis spectrum, dissolved organic carbon (DOC), specific UV absorbance (SUVA), UV absorption ratios, and excitation-emission matrix (EEM) fluorescence. The formation of disinfection by-products during HA sample chlorination was also identified, and CHCl3 was detected as the main disinfection by-product, but discharge plasma treatment could suppress its formation to a certain extent. In addition, approximately 82.3% and 67.9% of UV254 were removed for the Weihe River water and the Wetland water after 40 min of discharge plasma treatment.

  3. Effect of water blending on bioethanol HCCI combustion with forced induction and residual gas trapping

    Energy Technology Data Exchange (ETDEWEB)

    Megaritis, A. [Mechanical Engineering, School of Engineering and Design, Brunel University, West London, Uxbridge UB8 3PH (United Kingdom); Yap, D. [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); Wyszynski, M.L. [Mechanical and Manufacturing Engineering, School of Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2007-12-15

    There is increased interest worldwide in renewable engine fuels as well as in new combustion technologies. Bioethanol is one of the alternative fuels that have been used successfully in spark ignition engines. A combustion technology that currently attracts a lot of interest is the homogeneous charge compression ignition (HCCI) combustion, which has shown potential for low nitrogen oxides emissions with no particulate matter formation. The authors have shown previously that applying forced induction to bioethanol HCCI with residual gas trapping results in an extended load range compared to naturally aspirated operation. However, at high boost pressures, high cylinder pressure rise rates develop. Work by other researchers has shown that direct injection of water can be used as a combustion control method. The present work explores water blending as a way that might have an effect on combustion in order to lower the maximum pressure rise rates and further improve emissions. The obtained experimental results show that in contrast to variable rate direct injection of water, fixed rate water-ethanol blending is counterproductive for the reduction of pressure rise rates at higher loads. In addition, increasing the water content in ethanol results in reduction of the effective load range and increased emissions. (author)

  4. Water and dissolved gas geochemistry of the monomictic Paterno sinkhole (central Italy

    Directory of Open Access Journals (Sweden)

    Matteo Nocentini

    2012-07-01

    Full Text Available This paper describes the chemical and isotope features of water and dissolved gases from lake Paterno (max. depth 54 m, a sinkhole located in the NE sector of the S. Vittorino plain (Rieti, Central Italy, where evidences of past and present hydrothermal activity exists. In winter (February 2011 lake Paterno waters were almost completely mixed, whereas in summer time (July 2011 thermal and chemical stratifications established. During the stratification period, water and dissolved gas chemistry along the vertical water column were mainly controlled by biological processes, such as methanogenesis, sulfate-reduction, calcite precipitation, denitrification, and NH4 and H2 production. Reducing conditions at the interface between the bottom sediments and the anoxic waters are responsible for the relatively high concentrations of dissolved iron (Fe and manganese (Mn, likely present in their reduced oxidation state. Minerogenic and biogenic products were recognized at the lake bottom even during the winter sampling. At relatively shallow depth the distribution of CH4 and CO2 was controlled by methanotrophic bacteria and photosynthesis, respectively. The carbon isotope signature of CO2 indicates a significant contribution of deep-originated inorganic CO2 that is related to the hydrothermal system feeding the CO2-rich mineralized springs discharging in the surrounding areas of lake Paterno. The seasonal lake stratification likely controls the vertical and horizontal distribution of fish populations in the different periods of the year.

  5. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B., E-mail: otero@ien.gov.b, E-mail: cmnap@ien.gov.b, E-mail: brandao@ien.gov.b [Instituto de Engenharia Nuclear (DIRA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos

    2011-07-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  6. TREATMENT OF PRODUCED OIL AND GAS WATERS WITH SURFACTANT-MODIFIED ZEOLITE

    Energy Technology Data Exchange (ETDEWEB)

    Lynn E. Katz; E.J. Sullivan; R.S. Bowman

    2000-10-31

    Whereas most water produced from onshore oil and gas operations is disposed via reinjection, some waters, such as those from offshore production platforms, coastal production, and some onshore wells, must be treated to remove organic constituents before the water is discharged. Current methods for reducing residual free phases and dissolved organic carbon are not always fully effective in meeting regulatory limits. In addition, cost, space requirements, and ease of use are important factors in any treatment system. Surfactant-modified zeolite (SMZ) has been used successfully to treat contaminated ground water for organic and inorganic constituents. This research will use laboratory batch and column studies to design a field system that will be used to treat produced waters to reduce dissolved and free-phase organic constituents. The system will be designed to operate simply and to have low operating costs. Methods for regeneration of the spent zeolite will also be tested, as will the treatment system at a field production site in the final project task. Research over the past six months has focused on the method development, batch adsorption studies to demonstrate removal of target organic constituents, and the selection of a likely test site and characterization of produced waters from the site. Current contacts for selection, and ultimately, testing of example oil field waters include Phillips Petroleum Corp. (offshore location, Gulf of Mexico); MCA Petroleum Corporation in Flatonia, Texas; Amoco production in Farmington, New Mexico; and the New Mexico Bureau of Mines and Mineral Resources (mining operators for coal bed waters from the Farmington area). Water from Phillips Petroleum was received in August and analyzed at the University of Texas. These waters are being used in the laboratory to evaluate interactions between oil field waters and the SMZ. A site visit to MCA Petroleum operations was undertaken on October 12, 2000, and the analyses of samples taken

  7. Testing for Nonlinearity in Dynamic Characteristics of Vertical Upward Oil-Gas-Water Three-phase Bubble and Slug Flows

    Institute of Scientific and Technical Information of China (English)

    朱雷; 金宁德; 高忠科; 杜萌; 王振亚

    2012-01-01

    Based on the conductance fluctuation signals measured from vertical upward oil-gas-water three-phase flow experiment, time frequency representation and surrogate data method were used to investigate dynamical characteristics of oil-in-water type bubble and slug flows. The results indicate that oil-in-water type bubble flow will turn to deterministic motion with the increase of oil phase fraction f o and superficial gas velocity U sg under fixed flowrate of oil-water mixture Q mix . The dynamics of oil-in-water type slug flow becomes more complex with the increase of U sg under fixed flowrate of oil-water mixture. The change of f o leads to irregular influence on the dynamics of slug flow. These interesting findings suggest that the surrogate data method can be a faithful tool for characterizing dynamic characteristics of oil-in-water type bubble and slug flows.

  8. Treating Coalbed Natural Gas Produced Water for Beneficial Use By MFI Zeolite Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Robert Lee; Liangxiong Li

    2008-03-31

    Desalination of brines produced from oil and gas fields is an attractive option for providing potable water in arid regions. Recent field-testing of subsurface sequestration of carbon dioxide for climate management purposes provides new motivation for optimizing efficacy of oilfield brine desalination: as subsurface reservoirs become used for storing CO{sub 2}, the displaced brines must be managed somehow. However, oilfield brine desalination is not economical at this time because of high costs of synthesizing membranes and the need for sophisticated pretreatments to reduce initial high TDS and to prevent serious fouling of membranes. In addition to these barriers, oil/gas field brines typically contain high concentrations of multivalent counter cations (eg. Ca{sup 2+} and SO{sub 4}{sup 2-}) that can reduce efficacy of reverse osmosis (RO). Development of inorganic membranes with typical characteristics of high strength and stability provide a valuable option to clean produced water for beneficial uses. Zeolite membranes have a well-defined subnanometer pore structure and extreme chemical and mechanical stability, thus showing promising applicability in produced water purification. For example, the MFI-type zeolite membranes with uniform pore size of {approx}0.56 nm can separate ions from aqueous solution through a mechanism of size exclusion and electrostatic repulsion (Donnan exclusion). Such a combination allows zeolite membranes to be unique in separation of both organics and electrolytes from aqueous solutions by a reverse osmosis process, which is of great interest for difficult separations, such as oil-containing produced water purification. The objectives of the project 'Treating Coalbed Natural Gas Produced Water for Beneficial Use by MFI Zeolite Membranes' are: (1) to conduct extensive fundamental investigations and understand the mechanism of the RO process on zeolite membranes and factors determining the membrane performance, (2) to improve

  9. Influence of current velocity and wind speed on air-water gas exchange in a mangrove estuary

    Science.gov (United States)

    Ho, David T.; Coffineau, Nathalie; Hickman, Benjamin; Chow, Nicholas; Koffman, Tobias; Schlosser, Peter

    2016-04-01

    Knowledge of air-water gas transfer velocities and water residence times is necessary to study the fate of mangrove derived carbon exported into surrounding estuaries and ultimately to determine carbon balances in mangrove ecosystems. For the first time, the 3He/SF6 dual tracer technique, which has been proven to be a powerful tool to determine gas transfer velocities in the ocean, is applied to Shark River, an estuary situated in the largest contiguous mangrove forest in North America. The mean gas transfer velocity was 3.3 ± 0.2 cm h-1 during the experiment, with a water residence time of 16.5 ± 2.0 days. We propose a gas exchange parameterization that takes into account the major sources of turbulence in the estuary (i.e., bottom generated shear and wind stress).

  10. Inhibition of methane and natural gas hydrate formation by altering the structure of water with amino acids.

    Science.gov (United States)

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Han, Kunwoo; Ahn, Docheon; Cho, Seong Jun; Lee, Ju Dong; Lee, Kun-Hong

    2016-08-16

    Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has limited their extraction. Here, we report how the presence of amino acids in water induces changes in its structure and thus interrupts the formation of methane and natural gas hydrates. The perturbation of the structure of water by amino acids and the resulting selective inhibition of hydrate cage formation were observed directly. A strong correlation was found between the inhibition efficiencies of amino acids and their physicochemical properties, which demonstrates the importance of their direct interactions with water and the resulting dissolution environment. The inhibition of methane and natural gas hydrate formation by amino acids has the potential to be highly beneficial in practical applications such as hydrate exploitation, oil/gas transportation, and flow assurance. Further, the interactions between amino acids and water are essential to the equilibria and dynamics of many physical, chemical, biological, and environmental processes.

  11. Inhibition of methane and natural gas hydrate formation by altering the structure of water with amino acids

    Science.gov (United States)

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Han, Kunwoo; Ahn, Docheon; Cho, Seong Jun; Lee, Ju Dong; Lee, Kun-Hong

    2016-08-01

    Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has limited their extraction. Here, we report how the presence of amino acids in water induces changes in its structure and thus interrupts the formation of methane and natural gas hydrates. The perturbation of the structure of water by amino acids and the resulting selective inhibition of hydrate cage formation were observed directly. A strong correlation was found between the inhibition efficiencies of amino acids and their physicochemical properties, which demonstrates the importance of their direct interactions with water and the resulting dissolution environment. The inhibition of methane and natural gas hydrate formation by amino acids has the potential to be highly beneficial in practical applications such as hydrate exploitation, oil/gas transportation, and flow assurance. Further, the interactions between amino acids and water are essential to the equilibria and dynamics of many physical, chemical, biological, and environmental processes.

  12. 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.

  13. Plasma Spraying of Copper by Hybrid Water-Gas DC Arc Plasma Torch

    Science.gov (United States)

    Kavka, T.; Matějíček, J.; Ctibor, P.; Mašláni, A.; Hrabovský, M.

    2011-06-01

    Water-stabilized DC arc plasma torches offer a good alternative to common plasma sources used for plasma spraying applications. Unique properties of the generated plasma are determined by a specific plasma torch construction. This article is focused on a study of the plasma spraying process performed by a hybrid torch WSP500®-H, which combines two principles of arc stabilization—water vortex and gas flow. Spraying tests with copper powder have been carried out in a wide range of plasma torch parameters. First, analyses of particle in-flight behavior for various spraying conditions were done. After, particles were collected in liquid nitrogen, which enabled analyses of the particle in-flight oxidation. A series of spraying tests were carried out and coatings were analyzed for their microstructure, porosity, oxide content, mechanical, and thermal properties.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-02-15

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

  15. Water scaling in the North Sea oil and gas fields and scale prediction: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, M.

    1996-12-31

    Water-scaling is a common and major production chemistry problem in the North Sea oil and gas fields and scale prediction has been an important means to assess the potential and extent of scale deposition. This paper presents an overview of sulphate and carbonate scaling problems in the North Sea and a review of several widely used and commercially available scale prediction software. In the paper, the water chemistries and scale types and severities are discussed relative of the geographical distribution of the fields in the North Sea. The theories behind scale prediction are then briefly described. Five scale or geochemical models are presented and various definitions of saturation index are compared and correlated. Views are the expressed on how to predict scale precipitation under some extreme conditions such as that encountered in HPHT reservoirs. 15 refs., 7 figs., 9 tabs.

  16. Hot gas stripping of ammonia and carbon dioxide from simulated and actual in situ retort waters

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.L.

    1979-01-01

    This study proved that ammonia and carbon dioxide could be removed from retort water by hot gas stripping and that overall transfer rates were slower than for physical desorption alone. The ammonia in solution complexed with the carbonate species with the result that the CO/sub 2/ transfer rates were linked to the relatively slower desorption of NH/sub 3/ from solution. Ionic reactions in the liquid phase limited the quantity of free NH/sub 3/ and CO/sub 2/, thus decreasing the driving forces for mass transfer. The retort water exhibited foaming tendencies that affected the interfacial area which should be taken into account if a stripping tower is considered on a larger scale. Transfer unit heights were calculated for the process conditions studied and correlated such that scaleup to increased capacities is possible.

  17. Water transport in gas diffusion media for PEM fuel cells. Experimental and numerical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Joerg

    2010-08-20

    The water flux in partially saturated hydrophobic carbon fibre paper for polymer electrolyte membrane fuel cell applications is investigated and compared with the frequently used constitutive two-phase flow model based on Darcy's law. Further, the first steps towards a math-based material design for gas diffusion media are explored in this thesis. Two self-developed ex-situ experiments to investigate the liquid water transport are introduced. The first is a newly developed buoyancy-based measurement of the pressuresaturation relationship on thin porous material with an accuracy of 0.5 kPa for the pressure and {+-} 5% for the saturation. The second experiment measures the pressure drop in dependence of flow rates down to magnitudes of {mu}L/s across the partially saturated thin porous material. This flow rate is relevant for the fuel cell application. The liquid water transport through Toray 060 carbon fibre paper, impregnated with 7% and 10% PTFE is investigated at wet and dry boundary conditions. The experiments are also accompanied by analytical and numerical free surface modelling with the consideration of the material morphology and liquid-solid interaction. The imbibing and draining cases of an arrangement of six fibres at varying solid-liquid interaction and boundary conditions are studied with 'Surface Evolver'. In order to evaluate the findings of ex-situ and modelling work for applicability to water transport in fuel cell operation, the technique of nuclear magnetic resonance (NMR) imaging is assessed. The focus is on the visualisation of 2D and 3D water distribution in the operating fuel cell. The compatibility of the NMR experiment with fuel cell operation in relation to material selection, operating temperature, and current density is addressed. NMR imaging is employed for different current densities, stoichiometries, and fuel cell arrangements. The fuel cell arrangements differ by the cathode diffusion medium. Plain, hydrophobic, and

  18. Noble gas tracers of ventilation during deep-water formation in the Weddell Sea

    Science.gov (United States)

    Nicholson, D. P.; Khatiwala, S.; Heimbach, P.

    2016-05-01

    To explore the dynamics and implications of incomplete air-sea equilibration during the formation of abyssal water masses, we simulated noble gases in the Estimating the Circulation & Climate of the Ocean (ECCO) global ocean state estimate. A novel computation approach utilizing a matrix-free Newton-Krylov (MFNK) scheme was applied to quickly compute the periodic seasonal solutions for noble gas tracers. MFNK allows for quick computation of a cyclo-stationary solution for tracers (i.e., a spun-up, repeating seasonal cycle), which would otherwise be computationally infeasible due to the long time scale of dynamic adjustment of the abyssal ocean (1000’s of years). A suite of experiments isolates individual processes, including atmospheric pressure effects, the solubility pump and air-sea bubble fluxes. In addition to these modeled processes, a volumetric contribution of 0.28 ± 0.07% of glacial melt water is required to reconcile deep-water observations in the Weddell Sea. Another primary finding of our work is that the saturation anomaly of heavy noble gases in model simulations is in excess of two-fold more negative than is suggested from Weddell Sea observations. This result suggests that model water masses are insufficiently ventilated prior to subduction and thus there is insufficient communication between atmosphere and ocean at high latitudes. The discrepancy between noble gas observations and ECCO simulations highlights that important inadequacies remain in how we model high-latitude ventilation with large implications for the oceanic uptake and storage of carbon.

  19. Reducing greenhouse gas emissions, water use, and grain arsenic levels in rice systems.

    Science.gov (United States)

    Linquist, Bruce A; Anders, Merle M; Adviento-Borbe, Maria Arlene A; Chaney, Rufus L; Nalley, L Lanier; da Rosa, Eliete F F; van Kessel, Chris

    2015-01-01

    Agriculture is faced with the challenge of providing healthy food for a growing population at minimal environmental cost. Rice (Oryza sativa), the staple crop for the largest number of people on earth, is grown under flooded soil conditions and uses more water and has higher greenhouse gas (GHG) emissions than most crops. The objective of this study was to test the hypothesis that alternate wetting and drying (AWD--flooding the soil and then allowing to dry down before being reflooded) water management practices will maintain grain yields and concurrently reduce water use, greenhouse gas emissions and arsenic (As) levels in rice. Various treatments ranging in frequency and duration of AWD practices were evaluated at three locations over 2 years. Relative to the flooded control treatment and depending on the AWD treatment, yields were reduced by 63%, global warming potential (GWP of CH4 and N2 O emissions) reduced by 45-90%, and grain As concentrations reduced by up to 64%. In general, as the severity of AWD increased by allowing the soil to dry out more between flood events, yields declined while the other benefits increased. The reduction in GWP was mostly attributed to a reduction in CH4 emissions as changes in N2 O emissions were minimal among treatments. When AWD was practiced early in the growing season followed by flooding for remainder of season, similar yields as the flooded control were obtained but reduced water use (18%), GWP (45%) and yield-scaled GWP (45%); although grain As concentrations were similar or higher. This highlights that multiple environmental benefits can be realized without sacrificing yield but there may be trade-offs to consider. Importantly, adoption of these practices will require that they are economically attractive and can be adapted to field scales.

  20. Suppression of dioxins formation in flue gas by removal of hydrogen chloride using foaming water glass

    Energy Technology Data Exchange (ETDEWEB)

    Tsuyumoto, I. [Kanazawa Institute of Technology, Nonoichi, Ishikawa (Japan)

    2004-09-15

    Introduction Hydrogen chloride (HCl) is an acidic air pollutant emitted from municipal or industrial waste incinerators, and this causes the de novo synthesis of dioxins in flue gas. It is essential to remove hydrogen chloride from the flue gas to reduce dioxins emissions as well as to avoid air pollution. Calcium hydroxide (Ca(OH){sub 2}) is often used as a dry sorbent injected in a spray reactor to remove HCl from the flue gas. However, usage of Ca(OH){sub 2} has disadvantage in reaction efficiency, and Ca(OH){sub 2} powder is usually injected in large excess over ten times its chemical reaction stoichiometry. This brings about the increase of fly ash and the rise in pH, which is undesirable to reduce solid wastes and to suppress the elution of amphoteric metals such as Pb, Zn, Sn. Recently, we have developed ''foaming water glass (FWG)'' as a new wet sorbent for injection in a cooling tower to remove HCl and simultaneously to suppress dioxins formation. FWG is a kind of sodium silicate hydrate (lNa{sub 2}OmSiO{sub 2}nH{sub 2}O) and has a special property to form a foam over about 80 C. Here we present the properties of FWG as a HCl remover and investigate the potential to replace Ca(OH){sub 2}.

  1. Currents and convection cause enhanced gas exchange in the ice–water boundary layer

    Directory of Open Access Journals (Sweden)

    Brice Loose

    2016-12-01

    Full Text Available The presence of sea ice acts as a physical barrier for air–sea exchange. On the other hand it creates additional turbulence due to current shear and convection during ice formation. We present results from a laboratory study that demonstrate how shear and convection in the ice–ocean boundary layer can lead to significant gas exchange. In the absence of wind, water currents beneath the ice of 0.23 m s−1 produced a gas transfer velocity (k of 2.8 m d−1, equivalent to k produced by a wind speed of 7 m s−1 over the open ocean. Convection caused by air–sea heat exchange also increased k of as much as 131 % compared to k produced by current shear alone. When wind and currents were combined, k increased, up to 7.6 m d−1, greater than k produced by wind or currents alone, but gas exchange forcing by wind produced mixed results in these experiments. As an aggregate, these experiments indicate that using a wind speed parametrisation to estimate k in the sea ice zone may underestimate k by ca. 50 % for wind speeds <8 m s−1.

  2. Water Resource Impacts During Unconventional Shale Gas Development: The Pennsylvania Experience

    Science.gov (United States)

    Brantley, S. L.; Yoxtheimer, D.; Arjmand, S.; Grieve, P.; Vidic, R.; Abad, J. D.; Simon, C. A.; Pollak, J.

    2013-12-01

    The number of unconventional Marcellus shale wells in PA has increased from 8 in 2005 to more than 6000 today. This rapid development has been accompanied by environmental issues. We analyze publicly available data describing this Pennsylvania experience (data from www.shalenetwork.org and PA Department of Environmental Protection, i.e., PA DEP). After removing permitting and reporting violations, the average percent of wells/year with at least one notice of violation (NOV) from PA DEP is 35 %. Most violations are minor. An analysis of NOVs reported for wells drilled before 2013 revealed a rate of casing, cement, or well construction issues of 3.4%. Sixteen wells were given notices specifically related to migration of methane. A similarly low percent of wells were contaminated by brine components. Such contamination could derive from spills, subsurface migration of flowback water or shallow natural brines, or contamination by drill cuttings. Most cases of contamination of drinking water supplies with methane or brine components were reported in the previously glaciated part of the state. Before 2011, flowback and production water was often discharged legally into streams after minimal treatment, possibly increasing dissolved Br concentrations in some rivers. The rate of large spills or releases of gas-related industrial wastes in the state peaked in 2009 but little evidence of spills has been found in publicly available surface water chemistry data. The most likely indicators of spillage or subsurface release of flowback or production waters are the dissolved ions Na, Ca, and Cl. However, the data coverage for any given analyte is generally spatially and temporally sparse. Publicly available water quality data for before and after spills into Larrys Creek and Bobs Creek document the difficulties of detecting such events. An observation from the Pennsylvania experience is that the large number of people who have complained about their water supply (~1000 letters

  3. Laser absorption spectroscopy of water vapor confined in nanoporous alumina: wall collision line broadening and gas diffusion dynamics.

    Science.gov (United States)

    Svensson, Tomas; Lewander, Märta; Svanberg, Sune

    2010-08-02

    We demonstrate high-resolution tunable diode laser absorption spectroscopy (TDLAS) of water vapor confined in nanoporous alumina. Strong multiple light scattering results in long photon pathlengths (1 m through a 6 mm sample). We report on strong line broadening due to frequent wall collisions (gas-surface interactions). For the water vapor line at 935.685 nm, the HWHM of confined molecules are about 4.3 GHz as compared to 2.9 GHz for free molecules (atmospheric pressure). Gas diffusion is also investigated, and in contrast to molecular oxygen (that moves rapidly in and out of the alumina), the exchange of water vapor is found very slow.

  4. Cluster chemical reactions at mineral–liquid interface in metal leaching by photo-electroactive water-and-gas emulsions

    Science.gov (United States)

    Sekisov, AG

    2017-02-01

    Possibility of cluster (inter-cluster) reactions at the interface of mineral and liquid phases in leaching of metals mainly in dispersed cluster form by photo-electrically activated water-and-gas emulsions is theoretically evaluated. The governing role of active clusters of water and clustered hydrate envelopes generated under dissolution of active oxygen forms is determined. The scope of the study covers possible processes of transformation of clustered gold in mineral substance under direct interaction with the components of the active water-and-gas emulsions.

  5. Qualification of the ALKASORB sorbent for the sorption-enhanced water-gas shift process

    Energy Technology Data Exchange (ETDEWEB)

    Van Selow, E.R.; Cobden, P.D.; Dijk, Van H.A.J.; Walspurger, S.; Verbraeken, P.A.; Jansen, D.

    2013-07-01

    For the sorption-enhanced water-gas shift (SEWGS) process, a new sorbent material has been qualified in a reactor of 2 m length under conditions close to industrial designs. The sorbent ALKASORB is a potassium-carbonate promoted hydrotalcite-based compound. ALKASORB is shown to have many favourable properties in comparison to the reference sorbent, in particular with respect to mechanical stability. The cyclic capacity of the new compound is substantially higher than the cyclic capacity of the reference sorbent, and it allows a reduction of the steam requirement of 50%. The sorbent has demonstrated catalytic activity for the water-gas shift reaction that is sufficient to omit a separate catalyst. It is demonstrated that the sorbent remains chemically and mechanically stable during operation of at least 2000 adsorption-desorption cycles, even in the presence of H2S in the feed. H2S is shown not to influence CO2 adsorption capacity and is co-captured with the CO2. In contrast to the reference material that showed mechanical degradation during extended adsorption-desorption cycles, the new material is stable and allows to obtain carbon capture levels exceeding 95% more efficiently and more economically since the required size of the vessels will be smaller.

  6. Gas exchange and photosynthetic pigments in bell pepper irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Hidelblandi F. de Melo

    Full Text Available ABSTRACT The tools that evaluate the salinity effects on plants have great relevance as they contribute to understanding of the mechanisms of tolerance. This study aimed to evaluate gas exchanges and the contents of photosynthetic pigments in bell peppers cultivated with saline solutions (0, 1, 3, 5, 7 and 9 dS m-1 prepared using two sources: NaCl and a mixture of Ca, Mg, K, Na and Cl salts, in randomized blocks with a 6 x 2 factorial scheme and 4 replicates, totaling 48 experimental plots. The net photosynthesis (A, stomatal conductance (gs, transpiration (E, internal CO2 concentration (Ci, instantaneous carboxylation efficiency (A/Ci and water use efficiency (WUE, besides chlorophyll a, b and carotenoids were evaluated. The gas exchange parameters were efficient to indicate the effects of salinity. All photosynthetic pigments decreased with increased electrical conductivity, and the chlorophyll a is the most sensitive to salinity, while the water use efficiency increased with the increment of electrical conductivity.

  7. Estimating greenhouse gas fluxes from constructed wetlands used for water quality improvement

    Directory of Open Access Journals (Sweden)

    Sukanda Chuersuwan

    2014-06-01

    Full Text Available Methane (CH4 , nitrous oxide (N2O and carbon dioxide (CO2 fluxes were evaluated from constructed wetlands (CWs used to improve domestic wastewater quality. Experiments employed subsurface flow (SF and free water surface flow (FWS CWs planted with Cyperus spp. Results showed seasonal fluctuations of greenhouse gas fluxes. Greenhouse gas fluxes from SF-CWs and FWS-CWS were significantly different (p<0.05 while pollutant removal efficiencies of both CWs were not significantly different. The average CH4 , N2O and CO2 fluxes from SF-CWs were 2.9±3.5, 1.0±1.7, and 15.2±12.3 mg/m2 /hr, respectively, corresponding to the average global warming potential (GWP of 392 mg CO2 equivalents/m2 /hr. For FWS-CWs, the average CH4 , N2O and CO2 fluxes were 5.9±4.8, 1.8±1.0, and 29.6±20.2 mg/m2 /hr, respectively, having an average GWP of 698 mg CO2 equivalents/m2 /hr. Thus, FWS-CWs have a higher GWP than SF-CWs when they were used as a system for domestic water improvement.

  8. Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Chanenchuk, C.A.; Yates, I.C.; Satterfield, C.N.

    1990-01-01

    A Co/MgO/SiO[sub 2] Fischer-Tropsch catalyst was operated simultaneously with a Cu/ZnO/Al[sub 2]O[sub 3] water-gas-shift catalyst in a slurry reactor for over 400 hours. The process conditions were held constant at a temperature of 240[degrees]C, a pressure of 0.79 MPa, and a 1.1 H[sub 2]/CO feed of 0.065 Nl/min-g.cat. The Fischer-Tropsch activity remained constant at the level predicted by the operation of the Co/MgO/SiO[sub 2] catalyst alone. The water-gas-shift reaction was near equilibrium. The hydrocarbon product distribution of the combined catalyst system was stable and matched that of the CO/MgO/SiO[sub 2] operating alone under similar conditions. The combined catalyst system exhibited a high selectivity to n-alkanes. Neither catalysts's operation appeared to have a detrimental effect on that of the other, showing promise for future option.

  9. TRANSITION STATE FOR THE GAS-PHASE REACTION OF URANIUM HEXAFLUORIDE WITH WATER

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, S; James Becnel, J

    2008-03-18

    Density Functional Theory and small-core, relativistic pseudopotentials were used to look for symmetric and asymmetric transitions states of the gas-phase hydrolysis reaction of uranium hexafluoride, UF{sub 6}, with water. At the B3LYP/6-31G(d,p)/SDD level, an asymmetric transition state leading to the formation of a uranium hydroxyl fluoride, U(OH)F{sub 5}, and hydrogen fluoride was found with an energy barrier of +77.3 kJ/mol and an enthalpy of reaction of +63.0 kJ/mol (both including zero-point energy corrections). Addition of diffuse functions to all atoms except uranium led to only minor changes in the structure and relative energies of the reacting complex and transition state. However, a significant change in the product complex structure was found, significantly reducing the enthalpy of reaction to +31.9 kJ/mol. Similar structures and values were found for PBE0 and MP2 calculations with this larger basis set, supporting the B3LYP results. No symmetric transition state leading to the direct formation of uranium oxide tetrafluoride, UOF{sub 4}, was found, indicating that the reaction under ambient conditions likely includes several more steps than the mechanisms commonly mentioned. The transition state presented here appears to be the first published transition state for the important gas-phase reaction of UF{sub 6} with water.

  10. Controlling the Cross-Sensitivity of Carbon Nanotube-Based Gas Sensors to Water Using Zeolites.

    Science.gov (United States)

    Evans, Gwyn P; Buckley, David J; Adedigba, Abdul-Lateef; Sankar, Gopinathan; Skipper, Neal T; Parkin, Ivan P

    2016-10-05

    Carbon nanotube-based gas sensors can be used to detect harmful environmental pollutants such as NO2 at room temperature. Although they show promise as low-powered, sensitive, and affordable monitoring devices, cross-sensitivity of functionalized carbon nanotubes to water vapor often obscures the detection of target molecules. This is a barrier to adoption for monitoring of airborne pollutants because of the varying humidity levels found in real world environments. Zeolites, also known as molecular sieves because of their selective adsorption properties, are used in this work to control the cross-sensitivity of single-walled carbon nanotube (SWCNT)-based sensors to water vapor. Zeolites incorporated into the sensing layer are found to reduce interference effects that would otherwise obscure the identification of NO2 gas, permitting repeatable detection over a range of relative humidities. This significant improvement is found to depend on the arrangement of the SWCNT-zeolite layers in the sensing device, as well as the hydrophilicity of the chosen zeolite.

  11. Noble gas residence times of saline waters within crystalline bedrock, Outokumpu Deep Drill Hole, Finland

    Science.gov (United States)

    Kietäväinen, Riikka; Ahonen, Lasse; Kukkonen, Ilmo T.; Niedermann, Samuel; Wiersberg, Thomas

    2014-11-01

    Noble gas residence times of saline groundwaters from the 2516 m deep Outokumpu Deep Drill Hole, located within the Precambrian crystalline bedrock of the Fennoscandian Shield in Finland, are presented. The accumulation of radiogenic (4He, 40Ar) and nucleogenic (21Ne) noble gas isotopes in situ together with the effects of diffusion are considered. Fluid samples were collected from depths between 180 and 2480 m below surface, allowing us to compare the modelled values with the measured concentrations along a vertical depth profile. The results show that while the concentrations in the upper part are likely affected by diffusion, there is no indication of diffusive loss at or below 500 m depth. Furthermore, no mantle derived gases were found unequivocally. Previous studies have shown that distinct vertical variation occurs both in geochemistry and microbial community structuring along the drill hole, indicating stagnant waters with no significant exchange of fluids between different fracture systems or with surface waters. Therefore in situ accumulation is the most plausible model for the determination of noble gas residence times. The results show that the saline groundwaters in Outokumpu are remarkably old, with most of the samples indicating residence times between ∼20 and 50 Ma. Although being first order approximations, the ages of the fluids clearly indicate that their formation must predate more recent events, such as Quaternary glaciations. Isolation within the crust since the Eocene-Miocene epochs has also direct implications to the deep biosphere found at Outokumpu. These ecosystems must have been isolated for a long time and thus very likely rely on energy and carbon sources such as H2 and CO2 from groundwater and adjacent bedrock rather than from the ground surface.

  12. Technical Note: Detection of gas bubble leakage via correlation of water column multibeam images

    Directory of Open Access Journals (Sweden)

    J. Schneider von Deimling

    2012-03-01

    Full Text Available Hydroacoustic detection of natural gas release from the seafloor has been conducted in the past by using singlebeam echosounders. In contrast, modern multibeam swath mapping systems allow much wider coverage, higher resolution, and offer 3-D spatial correlation. Up to the present, the extremely high data rate hampers water column backscatter investigations and more sophisticated visualization and processing techniques are needed. Here, we present water column backscatter data acquired with a 50 kHz prototype multibeam system over a period of 75 seconds. Display types are of swath-images as well as of a "re-sorted" singlebeam presentation. Thus, individual and/or groups of gas bubbles rising from the 24 m deep seafloor clearly emerge in the acoustic images, making it possible to estimate rise velocities. A sophisticated processing scheme is introduced to identify those rising gas bubbles in the hydroacoustic data. We apply a cross-correlation technique adapted from particle imaging velocimetry (PIV to the acoustic backscatter images. Temporal and spatial drift patterns of the bubbles are assessed and are shown to match very well to measured and theoretical rise patterns. The application of this processing to our field data gives clear results with respect to unambiguous bubble detection and remote bubble rise velocimetry. The method can identify and exclude the main source of misinterpretations, i.e. fish-mediated echoes. Although image-based cross-correlation techniques are well known in the field of fluid mechanics for high resolution and non-inversive current flow field analysis, we present the first application of this technique as an acoustic bubble detector.

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

    Science.gov (United States)

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

    2015-01-01

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

  14. Application of bipolar gas discharge for water sterilization from S.aureus and E-coli

    Science.gov (United States)

    Taran, Anatoliy; Okhrimovskyy, Andriy; Komozynskyi, Petro; Kyslytsyn, Oleksandr; Taran, Svitlana; Filimonova, Nataliya; Lesnoy, Viktor; Oranska, Daria

    2016-09-01

    Recently, water treatment by gas discharge above the surface of the liquid has attracted a lot of attention. In most cases, however, the unipolar power source is used. Bipolar pulses of high voltage and current can increases degree of water sterilization from organic compounds, both chemical and bacterial since non equilibrium atmospheric plasma contains not only electrons but also positive and negative ions as well as an excited molecules or atoms and active radicals. Heavy charged particles of both signs, accelerated by bipolar electric field, can easily destroy chemical and biological contaminants in water. To evaluate this phenomenon, high voltage bipolar pulse generator was used. The amplitude of the pulse voltage was approaching value of 200 kV at the discharge ignition. The repetition time was varied from 1 to 14 milliseconds. Current pulse had a shape of a superposition of bipolar pulses with decaying amplitude. Liquid surface was used as a cathode or anode.Two types of contaminants, S.aureus and E.coli, with was 1 . 5 ×108 CFU/mL were treated by bipolar high voltage pulse discharge. After 30 minutes of exposition, no contaminants were observed within the water.

  15. Improving rice production sustainability by reducing water demand and greenhouse gas emissions with biodegradable films

    Science.gov (United States)

    Yao, Zhisheng; Zheng, Xunhua; Liu, Chunyan; Lin, Shan; Zuo, Qiang; Butterbach-Bahl, Klaus

    2017-01-01

    In China, rice production is facing unprecedented challenges, including the increasing demand, looming water crisis and on-going climate change. Thus, producing more rice at lower environmental cost is required for future development, i.e., the use of less water and the production of fewer greenhouse gas (GHG) per unit of rice. Ground cover rice production systems (GCRPSs) could potentially address these concerns, although no studies have systematically and simultaneously evaluated the benefits of GCRPS regarding yields and considering water use and GHG emissions. This study reports the results of a 2-year study comparing conventional paddy and various GCRPS practices. Relative to conventional paddy, GCRPSs had greater rice yields and nitrogen use efficiencies (8.5% and 70%, respectively), required less irrigation (-64%) and resulted in less total CH4 and N2O emissions (-54%). On average, annual emission factors of N2O were 1.67% and 2.00% for conventional paddy and GCRPS, respectively. A cost-benefit analysis considering yields, GHG emissions, water demand and labor and mulching costs indicated GCRPSs are an environmentally and economically profitable technology. Furthermore, substituting the polyethylene film with a biodegradable film resulted in comparable benefits of yield and climate. Overall, GCRPSs, particularly with biodegradable films, provide a promising solution for farmers to secure or even increase yields while reducing the environmental footprint.

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  17. Gas Engine-Driven Heat Pump Chiller for Air-Conditioning and Hot Water Supply Systems

    Science.gov (United States)

    Fujita, Toshihiko; Mita, Nobuhiro; Moriyama, Tadashi; Hoshino, Norimasa; Kimura, Yoshihisa

    In Part 1 of this study, the performance characteristics of a 457kW gas engine-driven heat pump (GHP) chiller have been obtained from a simulation model analysis for both cooling and heating modes and it has been found that the part-load characteristics of the GHP chiller are fairly well. On the back of Part 1, a computer simulation program has been developed for the evaluation of GHP chiller systems to compare with the other types of heat source systems for air-conditioning and hot water supply applications. The simulation program can be used to estimate annual energy consumption, annual CO2 emission, etc. of the systems with the data of monthly and hourly thermal loads on various buildings, outdoor air conditions, and characteristics of various components comprising the systems. By applying this to some cases of medium-scale hotel, office, shop, and hospital buildings, it has been found that the GHP chiller systems have advantages particularly in the cases of hotels and hospitals where a lot of hot water demand exists. It has also been found that the combination of a GHP chiller and a direct-fired absorption water chiller boiler (hot and chilled water generator) appears promising.

  18. Influence of infrastructure on water quality and greenhouse gas dynamics in urban streams

    Directory of Open Access Journals (Sweden)

    R. M. Smith

    2017-06-01

    Full Text Available Streams and rivers are significant sources of nitrous oxide (N2O, carbon dioxide (CO2, and methane (CH4 globally, and watershed management can alter greenhouse gas (GHG emissions from streams. We hypothesized that urban infrastructure significantly alters downstream water quality and contributes to variability in GHG saturation and emissions. We measured gas saturation and estimated emission rates in headwaters of two urban stream networks (Red Run and Dead Run of the Baltimore Ecosystem Study Long-Term Ecological Research project. We identified four combinations of stormwater and sanitary infrastructure present in these watersheds, including: (1 stream burial, (2 inline stormwater wetlands, (3 riparian/floodplain preservation, and (4 septic systems. We selected two first-order catchments in each of these categories and measured GHG concentrations, emissions, and dissolved inorganic and organic carbon (DIC and DOC and nutrient concentrations biweekly for 1 year. From a water quality perspective, the DOC : NO3− ratio of streamwater was significantly different across infrastructure categories. Multiple linear regressions including DOC : NO3− and other variables (dissolved oxygen, DO; total dissolved nitrogen, TDN; and temperature explained much of the statistical variation in nitrous oxide (N2O, r2 =  0.78, carbon dioxide (CO2, r2 =  0.78, and methane (CH4, r2 =  0.50 saturation in stream water. We measured N2O saturation ratios, which were among the highest reported in the literature for streams, ranging from 1.1 to 47 across all sites and dates. N2O saturation ratios were highest in streams draining watersheds with septic systems and strongly correlated with TDN. The CO2 saturation ratio was highly correlated with the N2O saturation ratio across all sites and dates, and the CO2 saturation ratio ranged from 1.1 to 73. CH4 was always supersaturated, with saturation ratios ranging from 3.0 to 2157. Longitudinal

  19. Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

    Energy Technology Data Exchange (ETDEWEB)

    Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

    1980-01-01

    Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

  20. Impacts from oil and gas produced water discharges on the gulf of Mexico hypoxic zone.

    Energy Technology Data Exchange (ETDEWEB)

    Parker, M. E.; Satterlee, K.; Veil, J. A.; Environmental Science Division; ExxonMobil Production Co.; Shell Offshore

    2006-01-01

    Shallow water areas of the Gulf of Mexico continental shelf experience low dissolved oxygen (hypoxia) each summer. The hypoxic zone is primarily caused by input of nutrients from the Mississippi and Atchafalaya Rivers. The nutrients stimulate the growth of phytoplankton, which leads to reduction of the oxygen concentration near the sea floor. During the renewal of an offshore discharge permit used by the oil and gas industry in the Gulf of Mexico, the U.S. Environmental Protection Agency (EPA) identified the need to assess the potential contribution from produced water discharges to the occurrence of hypoxia. The EPA permit required either that all platforms in the hypoxic zone submit produced water samples, or that industry perform a coordinated sampling program. This paper, based on a report submitted to EPA in August 2005 (1), describes the results of the joint industry sampling program and the use of those results to quantify the relative significance of produced water discharges in the context of other sources on the occurrence of hypoxia in the Gulf of Mexico. In the sampling program, 16 facilities were selected for multiple sampling - three times each at one month intervals-- and another 34 sites for onetime sampling. The goal of the sampling program was to quantify the sources and amount of oxygen demand associated with a variety of Gulf of Mexico produced waters. Data collected included direct oxygen demand measured by BOD5 (5-day biochemical oxygen demand) and TOC (total organic carbon) and indirect oxygen demand measured by nitrogen compounds (ammonia, nitrate, nitrate, and TKN [total Kjeldahl nitrogen]) and phosphorus (total phosphorus and orthophosphate). These data will serve as inputs to several available computer models currently in use for forecasting the occurrence of hypoxia in the Gulf of Mexico. The output of each model will be compared for consistency in their predictions and then a semi-quantitative estimate of the relative significance of

  1. CNMM: a Catchment Environmental Model for Managing Water Quality and Greenhouse Gas Emissions

    Science.gov (United States)

    Li, Y.

    2015-12-01

    Mitigating agricultural diffuse pollution and greenhouse gas emissions is a complicated task due to tempo-spatial lags between the field practices and the watershed responses. Spatially-distributed modeling is essential to the implementation of cost-effective and best management practices (BMPs) to optimize land uses and nutrient applications as well as to project the impact of climate change on the watershed service functions. CNMM (the Catchment Nutrients Management Model) is a 3D spatially-distributed, grid-based and process-oriented biophysical model comprehensively developed to simulate energy balance, hydrology, plant/crop growth, biogeochemistry of life elements (e.g., C, N and P), waste treatment, waterway vegetation/purification, stream water quality and land management in agricultural watersheds as affected by land utilization strategies such as BMPs and by climate change. The CNMM is driven by a number of spatially-distributed data such as weather, topography (including DEM and shading), stream network, stream water, soil, vegetation and land management (including waste treatments), and runs at an hourly time step. It represents a catchment as a matrix of square uniformly-sized cells, where each cell is defined as a homogeneous hydrological response unit with all the hydrologically-significant parameters the same but varied at soil depths in fine intervals. Therefore, spatial variability is represented by allowing parameters to vary horizontally and vertically in space. A four-direction flux routing algorithm is applied to route water and nutrients across soils of cells governed by the gradients of either water head or elevation. A linear channel reservoir scheme is deployed to route water and nutrients in stream networks. The model is capable of computing CO2, CH4, NH3, NO, N2O and N2 emissions from soils and stream waters. The CNMM can serve as an idea modelling tool to investigate the overwhelming critical zone research at various catchment scales.

  2. Gas transfer velocities for quantifying methane, oxygen and other gas fluxes through the air-water interface of wetlands with emergent vegetation

    Science.gov (United States)

    Poindexter, C.; Variano, E. A.

    2012-12-01

    Empirical models for the gas transfer velocity, k, in the ocean, lakes and rivers are fairly well established, but there are few data to predict k for wetlands. We have conducted experiments in a simulated emergent marsh in the laboratory to explore the relationship between k, wind shear and thermal convection. Now we identify the implications of these results for gas transfer in actual wetlands by (1) quantifying the range of wind conditions in emergent vegetation canopies and the range of thermal convection intensities in wetland water columns, and (2) describing the non-linear interaction of these two stirring forces over their relevant ranges in wetlands. We measured mean wind speeds and wind speed variance within the shearless region of a Schoenoplectus-Typha marsh canopy in the Sacramento-San Joaquin Delta (Northern California, USA). The mean wind speed within this region, , is significantly smaller than wind above the canopy. Based on our laboratory experiments, for calm or even average wind conditions in this emergent marsh k600 is only on the order 0.1 cm hr-1 (for neutrally or stably stratified water columns). We parameterize unstable thermal stratification and the resulting thermal convection using the heat flux through the air-water interface, q. We analyzed a water temperature record for the Schoenoplectus-Typha marsh to obtain a long-term heat flux record. We used these heat flux data along with short-term heat flux data from other wetlands in the literature to identify the range of the gas transfer velocity associated with thermal convection in wetlands. The typical range of heat fluxes through water columns shaded by closed emergent canopies (-200 W m-2 to +200 W m-2) yields k600 values of 0.5 - 2.5 cm hr-1 according to the model we developed in the laboratory. Thus for calm or average wind conditions, the gas transfer velocity associated with thermal convection is significantly larger than the gas transfer velocity associated with wind shear

  3. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    Science.gov (United States)

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-01

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  4. Water transport in gas diffusion media for PEM fuel cells. Experimental and numerical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Joerg

    2010-08-20

    The water flux in partially saturated hydrophobic carbon fibre paper for polymer electrolyte membrane fuel cell applications is investigated and compared with the frequently used constitutive two-phase flow model based on Darcy's law. Further, the first steps towards a math-based material design for gas diffusion media are explored in this thesis. Two self-developed ex-situ experiments to investigate the liquid water transport are introduced. The first is a newly developed buoyancy-based measurement of the pressuresaturation relationship on thin porous material with an accuracy of 0.5 kPa for the pressure and {+-} 5% for the saturation. The second experiment measures the pressure drop in dependence of flow rates down to magnitudes of {mu}L/s across the partially saturated thin porous material. This flow rate is relevant for the fuel cell application. The liquid water transport through Toray 060 carbon fibre paper, impregnated with 7% and 10% PTFE is investigated at wet and dry boundary conditions. The experiments are also accompanied by analytical and numerical free surface modelling with the consideration of the material morphology and liquid-solid interaction. The imbibing and draining cases of an arrangement of six fibres at varying solid-liquid interaction and boundary conditions are studied with 'Surface Evolver'. In order to evaluate the findings of ex-situ and modelling work for applicability to water transport in fuel cell operation, the technique of nuclear magnetic resonance (NMR) imaging is assessed. The focus is on the visualisation of 2D and 3D water distribution in the operating fuel cell. The compatibility of the NMR experiment with fuel cell operation in relation to material selection, operating temperature, and current density is addressed. NMR imaging is employed for different current densities, stoichiometries, and fuel cell arrangements. The fuel cell arrangements differ by the cathode diffusion medium. Plain, hydrophobic, and

  5. The hydraulic conductance of Fraxinus ornus leaves is constrained by soil water availability and coordinated with gas exchange rates.

    Science.gov (United States)

    Gortan, Emmanuelle; Nardini, Andrea; Gascó, Antonio; Salleo, Sebastiano

    2009-04-01

    Leaf hydraulic conductance (Kleaf) is known to be an important determinant of plant gas exchange and photosynthesis. Little is known about the long-term impact of different environmental factors on the hydraulic construction of leaves and its eventual consequences on leaf gas exchange. In this study, we investigate the impact of soil water availability on Kleaf of Fraxinus ornus L. as well as the influence of Kleaf on gas exchange rates and plant water status. With this aim, Kleaf, leaf conductance to water vapour (gL), leaf water potential (Psileaf) and leaf mass per area (LMA) were measured in F. ornus trees, growing in 21 different sites with contrasting water availability. Plants growing in arid sites had lower Kleaf, gL and Psileaf than those growing in sites with higher water availability. On the contrary, LMA was similar in the two groups. The Kleaf values recorded in sites with two different levels of soil water availability were constantly different from each other regardless of the amount of precipitation recorded over 20 days before measurements. Moreover, Kleaf was correlated with gL values. Our data suggest that down-regulation of Kleaf is a component of adaptation of plants to drought-prone habitats. Low Kleaf implies reduced gas exchange which may, in turn, influence the climatic conditions on a local/regional scale. It is concluded that leaf hydraulics and its changes in response to resource availability should receive greater attention in studies aimed at modelling biosphere-atmosphere interactions.

  6. Management of Water for Unconventional Oil and Gas Operations Enhanced with the Expanded U.S.Geological Survey Produced Waters Geochemical Database

    Science.gov (United States)

    Gans, K. D.; Blondes, M. S.; Thordsen, J. J.; Thomas, B.; Reidy, M. E.; Engle, M.; Kharaka, Y. K.; Rowan, E. L.

    2014-12-01

    Increases in hydraulic fracturing practices for shale gas and tight oil reservoirs have dramatically increased petroleum production in the USA, but have also made the issue of water management from these operations a high priority. Hydraulic fracturing requires ~ 10,000 to 50,000 m3 of water per well for injection in addition to water used to drill the well. Initially much of the water used for hydraulic fracturing was fresh water, but attitudes and operations are changing in response to costs and concerns. Concerns about groundwater depletion and contamination have prompted operators to increase the amount of produced water that can be recycled for hydraulic fracturing and to find suitable locations for salt-water injection. Knowledge of the geochemistry of produced waters is valuable in determining the feasibility of produced water recycling. Water with low salinity can be reclaimed for use outside of the petroleum industry (e.g. irrigation, municipal uses, and industrial operations). The updated and expanded USGS Produced Waters Database available at http://eerscmap.usgs.gov/pwapp/ will facilitate and enhance studies on management of water, including produced water, for unconventional oil and gas drilling and production. The USGS database contains > 160,000 samples. Expanding on the 2002 database, we have filled in state and regional gaps with information from conventional and unconventional wells and have increased the number of constituents to include minor and trace chemicals, isotopes, and time series data. We currently have produced water data from 5,200 tight gas wells, 4,500 coal-bed methane (CBM) wells, 3,500 shale gas wells, and 700 tight oil wells. These numbers will increase as we continue to receive positive responses from oil companies, state oil and gas commissions, and scientists wanting to contribute their data. This database is an important resource for a wide range of interested parties. Scientists from universities, government agencies, public

  7. Conformational preferences of γ-aminobutyric acid in the gas phase and in water

    Science.gov (United States)

    Song, Il Keun; Kang, Young Kee

    2012-09-01

    The conformational study of γ-aminobutyric acid (GABA) has been carried out at the M06-2X/cc-pVTZ level of theory in the gas phase and the SMD M06-2X/cc-pVTZ level of theory in water. In the gas phase, the folded conformation gG1 with gauche- and gauche+ conformations for the Cβsbnd Cα and Cγsbnd Cβ bonds, respectively, is found to be lowest in energy and enthalpy, which can be ascribed to the favored hyperconjugative n → π* interaction between the lone electron pair of the amine nitrogen atom and the Cdbnd O bond of the carboxylic group and the favored antiparallel dipole-dipole interaction between the Nsbnd H bond and the Cdbnd O bond. In addition, the intramolecular hydrogen bonds between the carboxylic group and the amine Nsbnd H group have contributed to stabilize some low-energy conformers. However, the most preferred conformation is found to be tG1 and more stable by 0.4 kcal/mol in ΔG than the conformer gG1, in which the favored entropic term due to the conformational flexibility and the other favored n → σ*, σ → σ*, and π → σ* interactions seem to play a role. The conformational preferences of the neutral GABA calculated by ΔG's are reasonably consistent with the populations deduced from FT microwave spectroscopy in supersonic jets combined with laser ablation. In water, the two folded conformers Gg and gG of the zwitterionic GABA are dominantly populated, each of which has the population of 47%, and the hydrogen bond between the ammonium Nsbnd H group and the lone electron pair of the Csbnd O- group seems to be crucial in stabilizing these conformers. Our calculated result that the folded conformers preferentially exist in water is consistent with the 1H NMR experiments in D2O.

  8. Unconventional oil and gas development and its stresses on water resources in the context of Water-Energy-Food Nexus: The case of Weld County, Colorado

    Science.gov (United States)

    Oikonomou, P. D.; Waskom, R.; Boone, K.; Ryan, J. N.

    2015-12-01

    The development of unconventional oil and gas resources in Colorado started to rapidly increase since the early 2000's. The recent oil price plunge resulted in a decline of well starts' rate in the US, but in Weld County, Colorado, it is currently at the 2013-levels. The additional water demand, despite its insignificant percentage in overall state's demand (0.1% in 2012), it competes with traditional ones, since Colorado's water is almost fully appropriated. Presently, the state has 53,597 active producing oil and gas wells. More than 40% of these are located in Weld County, which happens also to be one of top food production U.S. counties. The competition for land and water resources between the energy and agricultural sectors in water stressed areas, like the western U.S., is further intensified if recycle and reuse practices are not preferred to water disposal by the energy industry. Satisfying the multiple objectives of the Water-Energy-Food Nexus in order to achieve sustainable economic development requires balanced management of these resources. Identifying pressures on key areas that food and energy sectors are competing for water, is essential for prudent water management and developing appropriate policies. Weld County, as a water stressed and fossil fuel producing area, was selected for investigating current stresses on local water resources alongside with future climatic and water demand scenarios for exploring probable long-term effects.

  9. Drinking hydrogen water and intermittent hydrogen gas exposure, but not lactulose or continuous hydrogen gas exposure, prevent 6-hydorxydopamine-induced Parkinson’s disease in rats

    Directory of Open Access Journals (Sweden)

    Ito Mikako

    2012-05-01

    Full Text Available Abstract Background Lactulose is a synthetic disaccharide that can be catalyzed only by intestinal bacteria in humans and rodents, and a large amount of hydrogen is produced by bacterial catalysis of lactulose. We previously reported marked effects of ad libitum administration of hydrogen water on prevention of a rat model of Parkinson’s disease (PD. Methods End-alveolar breath hydrogen concentrations were measured in 28 healthy subjects and 37 PD patients, as well as in 9 rats after taking hydrogen water or lactulose. Six-hydroxydopamine (6-OHDA-induced hemi-PD model was stereotactically generated in rats. We compared effects of hydrogen water and lactulose on prevention of PD. We also analyzed effects of continuous and intermittent administration of 2% hydrogen gas. Results Hydrogen water increased breath hydrogen concentrations from 8.6 ± 2.1 to 32.6 ± 3.3 ppm (mean and SEM, n = 8 in 10 min in healthy subjects. Lactulose increased breath hydrogen concentrations in 86% of healthy subjects and 59% of PD patients. Compared to monophasic hydrogen increases in 71% of healthy subjects, 32% and 41% of PD patients showed biphasic and no increases, respectively. Lactulose also increased breath hydrogen levels monophasically in 9 rats. Lactulose, however, marginally ameliorated 6-OHDA-induced PD in rats. Continuous administration of 2% hydrogen gas similarly had marginal effects. On the other hand, intermittent administration of 2% hydrogen gas prevented PD in 4 of 6 rats. Conclusions Lack of dose responses of hydrogen and the presence of favorable effects with hydrogen water and intermittent hydrogen gas suggest that signal modulating activities of hydrogen are likely to be instrumental in exerting a protective effect against PD.

  10. Constraints of gas venting activity for the interstitial water geochemistry at the shallow gas hydrate site, eastern margin of the Japan Sea; results from high resolution time-series fluid sampling by OsmoSampler

    Science.gov (United States)

    Owari, S.; Tomaru, H.; Matsumoto, R.

    2016-12-01

    We have conducted ROV researches in the eastern margin of the Japan Sea where active gas venting and outcropping of gas hydrates were observed near the seafloor and have found the strength and location of venting had changed within a few days. These observations indicate the seafloor environments with the shallow gas hydrate system could have changed for short period compared to a geological time scale. We have applied a long-term osmotic fluid sampling system "OsmoSampler" on the active gas hydrate system for one year in order to document how the gas venting and gas hydrate activity have changed the geochemical environments near the seafloor. All the major ion concentrations in the interstitial water show synchronous increase and decrease repeatedly in three to five days, reflecting the incorporation and release of fresh water in gas hydrates in response to the gas concentration change near the sampling site. Dissolved methane concentration increases rapidly and excessively (over several mM) in the first 40 days corresponding to the active gas venting. The increases of methane concentration are often associated with high ion concentration during high water pressure period, indicating excess gas release from shallow gas pockets. Contrarily, enhanced gas hydrate growth may plug the fluid-gas paths in shallow sediment, reducing gas hydrate formation due to the decrease of methane flux. This study was conducted under the commission from AIST as a part of the methane hydrate research project funded by METI (the Ministry of Economy, Trade and Industry, Japan).

  11. Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Liukang [LI-COR Inc., Lincoln, NE (United States); McDermitt, Dayle [LI-COR Inc., Lincoln, NE (United States); Anderson, Tyler [LI-COR Inc., Lincoln, NE (United States); Riensche, Brad [LI-COR Inc., Lincoln, NE (United States); Komissarov, Anatoly [LI-COR Inc., Lincoln, NE (United States); Howe, Julie [LI-COR Inc., Lincoln, NE (United States)

    2012-02-01

    Robust, economical, low-power and reliable closed-path methane (CH4), carbon dioxide (CO2), and water vapor (H2O) analyzers suitable for long-term measurements are not readily available commercially. Such analyzers are essential for quantifying the amount of CH4 and CO2 released from various ecosystems (wetlands, rice paddies, forests, etc.) and other surface contexts (e.g. landfills, animal husbandry lots, etc.), and for understanding the dynamics of the atmospheric CH4 and CO2 budget and their impact on climate change and global warming. The purpose of this project is to develop a closed-path methane, carbon dioxide gas and water vapor analyzer capable of long-term measurements in remote areas for global climate change and environmental research. The analyzer will be capable of being deployed over a wide range of ecosystems to understand methane and carbon dioxide exchange between the atmosphere and the surface. Measurements of methane and carbon dioxide exchange need to be made all year-round with limited maintenance requirements. During this Phase II effort, we successfully completed the design of the electronics, optical bench, trace gas detection method and mechanical infrastructure. We are using the technologies of two vertical cavity surface emitting lasers, a multiple-pass Herriott optical cell, wavelength modulation spectroscopy and direct absorption to measure methane, carbon dioxide, and water vapor. We also have designed the instrument application software, Field Programmable Gate Array (FPGA), along with partial completion of the embedded software. The optical bench has been tested in a lab setting with very good results. Major sources of optical noise have been identified and through design, the optical noise floor is approaching -60dB. Both laser modules can be temperature controlled to help maximize the stability of the analyzer. Additionally, a piezo electric transducer has been

  12. Experimental investigation of gas hydrate formation, plugging and transportability in partially dispersed and water continuous systems

    Science.gov (United States)

    Vijayamohan, Prithvi

    As oil/gas subsea fields mature, the amount of water produced increases significantly due to the production methods employed to enhance the recovery of oil. This is true especially in the case of oil reservoirs. This increase in the water hold up increases the risk of hydrate plug formation in the pipelines, thereby resulting in higher inhibition cost strategies. A major industry concern is to reduce the severe safety risks associated with hydrate plug formation, and significantly extending subsea tieback distances by providing a cost effective flow assurance management/safety tool for mature fields. Developing fundamental understanding of the key mechanistic steps towards hydrate plug formation for different multiphase flow conditions is a key challenge to the flow assurance community. Such understanding can ultimately provide new insight and hydrate management guidelines to diminish the safety risks due to hydrate formation and accumulation in deepwater flowlines and facilities. The transportability of hydrates in pipelines is a function of the operating parameters, such as temperature, pressure, fluid mixture velocity, liquid loading, and fluid system characteristics. Specifically, the hydrate formation rate and plugging onset characteristics can be significantly different for water continuous, oil continuous, and partially dispersed systems. The latter is defined as a system containing oil/gas/water, where the water is present both as a free phase and partially dispersed in the oil phase (i.e., entrained water in the oil). Since hydrate formation from oil dispersed in water systems and partially dispersed water systems is an area which is poorly understood, this thesis aims to address some key questions in these systems. Selected experiments have been performed at the University of Tulsa flowloop to study the hydrate formation and plugging characteristics for the partially dispersed water/oil/gas systems as well as systems where the oil is completely dispersed

  13. Determination of Prometryn in Vetiver Grass and Water Using Gas Chromatography-Nitrogen Chemiluminescence Detection.

    Science.gov (United States)

    Sun, Shixian; Li, Yongmei; Lv, Ping; Punamiya, Pravin; Sarkar, Dibyendu; Dan, Youming; Ma, Junrong; Zheng, Yi

    2016-02-01

    Nitrogen chemiluminescence detector (NCD) is a nitrogen-specific detector that responds to ammonia, hydrazine, hydrogen cyanide and nitrogen oxide. A method to analyze the herbicide prometryn in plant and water samples was developed using gas chromatograph (GC) coupled with NCD. Extracts from plant (vetiver grass) and water matrices were analyzed for prometryn using an Agilent 7890A GC coupled with an Agilent 255 NCD in a split injection mode with a ratio of 2 : 1. Separation was carried out at 200°C and combustion at 1,018°C with H2 and O2 following optimized method development conditions. The percent recovery of prometryn in the two different matrices tested ranged from 81 to 107%, with relative standard deviations varying from 0.10 to 3.30% for spiked samples. Detection limit of the proposed method was 0.02 µg mL(-1) and the limit of quantification was 0.06 µg mL(-1). The proposed GC-NCD method was successfully applied to determine prometryn extracted from plant and water samples without potential interference of S-triazine, a pesticide from the same group. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Detection of water molecules in inert gas based plasma by the ratios of atomic spectral lines

    Science.gov (United States)

    Bernatskiy, A. V.; Ochkin, V. N.

    2017-01-01

    A new approach is considered to detect the water leaks in inert plasma-forming gas present in the reactor chamber. It is made up of the intensity ratio of D α and H α spectral lines in combination with O, Ar and Xe lines intensity. The concentrations of H2O, O, H and D particles have been measured with high sensitivity. At the D2 admixture pressure {{p}{{\\text{D}\\text{2}}}}   =  0.025 mbar, we used the acquisition time of 10 s to measure the rate of water molecules injected from the outside, Γ0  =  1.4 · 10-9 mbar · m3 · s-1, and the incoming water molecules to plasma, Γ  =  5 ·10-11 mbar · m3 · s-1. The scaling proves that at small D2 admixtures (10-4 mbar), the leaks with the rates Γ0  ≈  6 · 10-12 mbar · m3 · s-1 and Γ  ≈  2 · 10-13 mbar · m3 · s-1 can be detected and measured. The difference between Γ0 and Γ values is due to the high degree of H2O dissociation, which can be up to 97-98%.

  15. Gas exchange and leaf contents in bell pepper under energized water and biofertilizer doses

    Directory of Open Access Journals (Sweden)

    Francisca R. M. Borges

    2016-06-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the effect of energized water and bovine biofertilizer doses on the gas exchange and NPK contents in leaves of yellow bell pepper plants. The experiment was conducted at the experimental area of the Federal University of Ceará, in Fortaleza-CE, Brazil, from June to November 2011. The experiment was set in a randomized block design, in a split-plot scheme; the plots were composed of treatments with energized and non-energized water and the subplots of five doses of liquid biofertilizer (0, 250, 500, 750 and 1000 mL plant-1 week-1. The following variables were analyzed: transpiration, stomatal conductance, photosynthesis and leaf contents of nitrogen (N, phosphorus (P and potassium (K. Water energization did not allow significant increases in the analyzed variables. The use of biofertilizer as the only source of fertilization was sufficient to provide the nutrients N, P and K at appropriate levels for the bell pepper crop.

  16. A cost-benefit analysis of produced water management opportunities in selected unconventional oil and gas plays

    Science.gov (United States)

    Marsters, P.; Macknick, J.; Bazilian, M.; Newmark, R. L.

    2013-12-01

    Unconventional oil and gas production in North America has grown enormously over the past decade. The combination of horizontal drilling and hydraulic fracturing has made production from shale and other unconventional resources economically attractive for oil and gas operators, but has also resulted in concerns over potential water use and pollution issues. Hydraulic fracturing operations must manage large volumes of water on both the front end as well as the back end of operations, as significant amounts of water are coproduced with hydrocarbons. This water--often called flowback or produced water--can contain chemicals from the hydraulic fracturing fluid, salts dissolved from the source rock, various minerals, volatile organic chemicals, and radioactive constituents, all of which pose potential management, safety, and public health issues. While the long-term effects of hydraulic fracturing on aquifers, drinking water supplies, and surface water resources are still being assessed, the immediate impacts of produced water on local infrastructure and water supplies are readily evident. Produced water management options are often limited to underground injection, disposal at centralized treatment facilities, or recycling for future hydraulic fracturing operations. The costs of treatment, transport, and recycling are heavily dependent on local regulations, existing infrastructure, and technologies utilized. Produced water treatment costs also change over time during energy production as the quality of the produced water often changes. To date there is no publicly available model that evaluates the cost tradeoffs associated with different produced water management techniques in different regions. This study addresses that gap by characterizing the volume, qualities, and temporal dynamics of produced water in several unconventional oil and gas plays; evaluating potential produced water management options, including reuse and recycling; and assessing how hydraulic

  17. Analysis of Water Hammer with Different Closing Valve Laws on Transient Flow of Hydrogen-Natural Gas Mixture

    OpenAIRE

    Norazlina Subani; Norsarahaida Amin

    2015-01-01

    Water hammer on transient flow of hydrogen-natural gas mixture in a horizontal pipeline is analysed to determine the relationship between pressure waves and different modes of closing and opening of valves. Four types of laws applicable to closing valve, namely, instantaneous, linear, concave, and convex laws, are considered. These closure laws describe the speed variation of the hydrogen-natural gas mixture as the valve is closing. The numerical solution is obtained using the reduced order m...

  18. The Effect of Water Stress on the Gas Exchange Parameters, Productivity and Seed Health of Buckwheat (Fagopyrum esculentum Moench

    Directory of Open Access Journals (Sweden)

    Agnieszka Pszczółkowska

    2012-12-01

    Full Text Available The present pot experiment studied the effect of different soil moisture contents (60 - 70% CWC (capillary water capacity - control; 30 - 35% CWC - water stress on buckwheat productivity, the gas exchange parameters and health of buckwheat nuts. It was found that water deficit affected adversely certain biometric features investigated (plant height, number of nuts per cluster and caused a decrease in seed weight per plant. It was also shown that water stress reduced the values of the investigated gas exchange parameters (photosynthesis rate, transpiration rate, intercellular-space CO2 concentration, and stomatal conductance relative to the control treatment. Different soil moisture contents did not have a clear effect on fungal colonization of seeds. The multiplex PCR assays did not enable the detection of the genes responsible for mycotoxin synthesis. Under water deficit conditions, an increase was found in the content of albumin and globulin fractions as well as of glutelin fractions.

  19. Deviation of Carbon Dioxide-Water Gas-Liquid Balance from Thermodynamic Equilibrium in Turbulence I:Experiment and Correlation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenzhen; QIAN Zhi; XU Lianbin; WU Caiyan; GUO Kai

    2013-01-01

    The carbon dioxide-water system was used to investigate the flowing gas-liquid metastable state.The experiment was carried out in a constant volume vessel with a horizontal circulation pipe and a peristaltic pump forced CO2 saturated water to flow.The temperature and pressure were recorded.The results showed that some CO2 escaped from the water in the flow process and the pressure increased,indicating that the gas-liquid equilibrium was broken.The amount of escaped CO2 varied with flow speed and reached a limit in a few minutes,entitled dynamic equilibrium.Temperature and liquid movement played the same important role in breaking the phase equilibrium.Under the experimental conditions,the ratio of the excessive carbon dioxide in the gas phase to its thermodynamic equilibrium amount in the liquid could achieve 15%.

  20. Saline gas-produced waters treatment with macrophytes in a hydroponic system. Final report, July 1, 1991-December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Jewell, W.J.; Albright, L.D.; Cummings, R.J.; Hicks, E.E.; Nock, T.D.

    1993-06-01

    A review of potential pollution problems of natural gas produced waters emphasized that present regulations do not adversely affect gas production, but future changes may be a concern (Fillo et al.). Also, the economics of the present treatment and disposal practices are becoming unacceptably high. Thus, new and more effective methods of treating and disposing of produced waters should be sought. A hydroponic system has been developed at Cornell University and piloted on domestic sewage partly with support from the Gas Research Institute, the U.S. Department of Energy (SERI), USEPA and New York State Energy Research and Development Authority (Jewell et al.). The hydroponic plant system is referred to as the 'Nutrient Film Technique' (NFT). The general goal of the project is to conduct a preliminary study to determine the feasibility of developing a biological treatment system capable of removing organic and inorganic pollutants from highly saline waters while minimizing the effluent volume by enhanced evapotranspiration.

  1. The Energy, Greenhouse Gas Emissions, and Cost Implications of Municipal Water Supply & Wastewater Treatment

    Science.gov (United States)

    Rodriguez-Winter, Thelma

    All man-made structures and materials have a design life. Across the United States there is a common theme for our water and wastewater treatment facilities and infrastructure. The design life of many of our mid 20 th century water and wastewater infrastructures in the United States have reached or are reaching life expectancy limits (ASCE, 2010). To compound the financial crisis of keeping up with the degradation, meeting and exceeding quality standards has never been more important in order to protect local fresh water supplies. This thesis analyzes the energy consumption of a municipal water and wastewater treatment system from a Lake Erie intake through potable treatment and back through wastewater treatment then discharge. The system boundary for this thesis includes onsite energy consumed by the treatment system and distribution/reclamation system as well as the energy consumed by the manufacturing of treatment chemicals applied during the study periods. By analyzing energy consumption, subsequent implications from greenhouse gas emissions and financial expenditures were quantified. Through the segregation of treatment and distribution processes from non-process energy consumption, such as heating, lighting, and air handling, this study identified that the potable water treatment system consumed an annual average of 2.42E+08 kBtu, spent 5,812,144 for treatment and distribution, and emitted 28,793 metric tons of CO2 equivalent emissions. Likewise, the wastewater treatment system consumed an annual average of 2.45E+08 kBtu, spent 3,331,961 for reclamation and treatment, and emitted 43,780 metric tons of CO2 equivalent emissions. The area with the highest energy usage, financial expenditure, and greenhouse gas emissions for the potable treatment facility and distribution system was from the manufacturing of the treatment chemicals, 1.10E+08 kBtu, 3.7 million, and 17,844 metric tons of CO2 equivalent, respectively. Of the onsite energy (1.4E-03 kWh per gallon

  2. Gas/Water and Heat Management of PEM-Based Fuel Cell and Electrolyzer Systems for Space Applications

    Science.gov (United States)

    Guo, Qing; Ye, Fang; Guo, Hang; Ma, Chong Fang

    2016-11-01

    Hydrogen/oxygen fuel cells were successfully utilized in the field of space applications to provide electric energy and potable water in human-rated space mission since the 1960s. Proton exchange membrane (PEM) based fuel cells, which provide high power/energy densities, were reconsidered as a promising space power equipment for future space exploration. PEM-based water electrolyzers were employed to provide life support for crews or as major components of regenerative fuel cells for energy storage. Gas/water and heat are some of the key challenges in PEM-based fuel cells and electrolytic cells, especially when applied to space scenarios. In the past decades, efforts related to gas/water and thermal control have been reported to effectively improve cell performance, stability lifespan, and reduce mass, volume and costs of those space cell systems. This study aimed to present a primary review of research on gas/water and waste thermal management for PEM-based electrochemical cell systems applied to future space explorations. In the fuel cell system, technologies related to reactant supplement, gas humidification, water removal and active/passive water separation were summarized in detail. Experimental studies were discussed to provide a direct understanding of the effect of the gas-liquid two-phase flow on product removal and mass transfer for PEM-based fuel cell operating in a short-term microgravity environment. In the electrolyzer system, several active and static passive phaseseparation methods based on diverse water supplement approaches were discussed. A summary of two advanced passive thermal management approaches, which are available for various sizes of space cell stacks, was specifically provided

  3. Gas/Water and Heat Management of PEM-Based Fuel Cell and Electrolyzer Systems for Space Applications

    Science.gov (United States)

    Guo, Qing; Ye, Fang; Guo, Hang; Ma, Chong Fang

    2017-02-01

    Hydrogen/oxygen fuel cells were successfully utilized in the field of space applications to provide electric energy and potable water in human-rated space mission since the 1960s. Proton exchange membrane (PEM) based fuel cells, which provide high power/energy densities, were reconsidered as a promising space power equipment for future space exploration. PEM-based water electrolyzers were employed to provide life support for crews or as major components of regenerative fuel cells for energy storage. Gas/water and heat are some of the key challenges in PEM-based fuel cells and electrolytic cells, especially when applied to space scenarios. In the past decades, efforts related to gas/water and thermal control have been reported to effectively improve cell performance, stability lifespan, and reduce mass, volume and costs of those space cell systems. This study aimed to present a primary review of research on gas/water and waste thermal management for PEM-based electrochemical cell systems applied to future space explorations. In the fuel cell system, technologies related to reactant supplement, gas humidification, water removal and active/passive water separation were summarized in detail. Experimental studies were discussed to provide a direct understanding of the effect of the gas-liquid two-phase flow on product removal and mass transfer for PEM-based fuel cell operating in a short-term microgravity environment. In the electrolyzer system, several active and static passive phaseseparation methods based on diverse water supplement approaches were discussed. A summary of two advanced passive thermal management approaches, which are available for various sizes of space cell stacks, was specifically provided

  4. Effect of Non-Condensable Gas Mass Fraction on Condensation Heat Transfer for Water-Ethanol Vapor Mixture

    Science.gov (United States)

    Wang, Shixue; Utaka, Yoshio

    The condensation heat transfer characteristic curves for a ternary vapor mixture of water, ethanol and air (or nitrogen) under several ethanol concentrations and relatively low concentrations of air (or nitrogen) were measured. The effect of non-condensable gas on several different domains in the condensation curves was discussed. The effect of non-condensable gas in the domains controlled by the diffusion resistance and the filmwise condensation was not notable; whereas that in the domain dominated by the condensate resistance of dropwise mode was remarkable. Moreover, variations due to changes in non-condensable gas concentration of several characteristic points representing the curves were discussed.

  5. Offshore conversion of associated gas to synthetic crude oil: An economic option for deep water and marginal fields

    Energy Technology Data Exchange (ETDEWEB)

    Antia, D.D.J.; Seddon, D.

    1995-12-31

    A low cost modular Fischer Tropsch gas conversion approach which can add value to associated gas in both deep water and marginal fields is described. The process is suitable for location on vessels (FPSO`s), jackups, platforms and semisubmersibles. It can economically convert >1 to >200 MMCF/D to syncrude. The modules can be used to: Strip value from gas prior to injection; Remove a reinjection or flaring requirement; Reduce carbon dioxide emissions from the field. Conversion ratios depend on the catalyst and process configuration used. They range from 70-->170 Bbls/MMCF.

  6. Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

    Energy Technology Data Exchange (ETDEWEB)

    Kassotis, Christopher D., E-mail: christopher.kassotis@duke.edu [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Iwanowicz, Luke R. [U.S. Geological Survey, Leetown Science Center, Fish Health Branch, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam C. [U.S. Geological Survey, National Research Program, 12201 Sunrise Valley Drive, MS 430, Reston, VA 20192 (United States); Orem, William H. [U.S. Geological Survey, Eastern Energy Resources Science Center, 12201 Sunrise Valley Drive, MS 956, Reston, VA 20192 (United States); Nagel, Susan C., E-mail: nagels@health.missouri.edu [Department of Obstetrics, Gynecology and Women' s Health, University of Missouri, Columbia, MO 65211 (United States)

    2016-07-01

    Currently, > 95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby. - Highlights: • Oil and gas wastewater disposal may increase endocrine disrupting activity in water. • Tested EDC activity in surface water near oil and gas wastewater injection site. • Water downstream had significantly

  7. Water-gas shift on gold catalysts: catalyst systems and fundamental studies.

    Science.gov (United States)

    Tao, Franklin Feng; Ma, Zhen

    2013-10-07

    Since the pioneering finding by Haruta et al. that small gold nanoparticles on reducible supports can be highly active for low-temperature CO oxidation, the synthesis, characterization, and application of supported gold catalysts have attracted much attention. The water-gas shift reaction (WGSR: CO + H2O = CO2 + H2) is important for removing CO and upgrading the purity of H2 for fuel cell applications, ammonia synthesis, and selective hydrogenation processes. In recent years, much attention has been paid to exploration the possibility of using supported gold nanocatalysts for WGSR and understanding the fundamental aspects related to catalyst deactivation mechanisms, nature of active sites, and reaction mechanisms. Here we summarize recent advances in the development of supported gold catalysts for this reaction and fundamental insights that can be gained, and furnish our assessment on the status of research progress.

  8. Reverse water gas shift reaction over Co-precipitated Ni-CeO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    WANG Luhui; ZHANG Shaoxing; LIU Yuan

    2008-01-01

    The Ni-CeO2 catalysts with different Ni contents were prepared by a co-precipitation method and used for Reverse Water Gas Shift (RWGS) reaction. 2wt.%Ni-CeO2 showed excellent catalytic performance in terms of activity, selectivity, and stability for RWGS reaction. Characterizations of the catalyst samples were conducted by XRD and TPR. The results indicated that, in Ni-CeO2 catalysts, there were three kinds of nickel, nickel ions in ceria lattice, highly dispersed NiO and bulk NiO. Oxygen vacancies were formed in CeO2 lattice due to the incorporation of Ni2+ ions into ceria lattice. Oxygen vacancies formed in ceda lattice and highly dispersed Ni were key active components for RWGS, and bulk Ni was key active component for methanation of CO2.

  9. Theoretical study of water-gas shift reaction on the silver nanocluster

    Science.gov (United States)

    Arab, Ali; Sharafie, Darioush; Fazli, Mostafa

    2017-10-01

    The kinetics of water gas shift reaction (WGSR) on the silver nanocluster was investigated using density functional theory according to the carboxyl associative mechanism. The hybrid B3PW91 functional along with the 6-31+G* and LANL2DZ basis sets were used throughout the calculations. It was observed that CO and H2O molecules adsorb physically on the Ag5 cluster without energy barrier as the initial steps of WGSR. The next three steps including H2Oads dissociation, carboxyl (OCOHads) formation, and CO2(ads) formation were accompanied by activation barrier. Transition states, as well as energy profiles of these three steps, were determined and analyzed. Our results revealed that the carboxyl and CO2(ads) formation were fast steps whereas H2Oads dissociation was the slowest step of WGSR.

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

    Science.gov (United States)

    Ambrosi, Andrea; Denmark, Scott E

    2016-09-26

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

  11. Gas chromatographic thermodynamics on hydration processes of magnesium chloride with low water

    Institute of Scientific and Technical Information of China (English)

    陈建军; 陈关城; 马培华; 保积庆; 马玉涛; 陈丰秋

    2003-01-01

    The dehydration and hydration processes of magnesium chloride hydrates were studied by means of frontal chromatography analysis, calorimetry, thermogravimetry and chemical analysis. The mathematical imitation for the adsorption isotherms of MgCl2*4H2O and MgCl2*2H2O at different temperatures indicates that Boltzmann Function is the ideal equation to describe those adsorption isotherms. Its adsorption heat is -13.06kJ/mol and -16.11kJ/mol, respectively. The adsorption equilibrium constants are also given. From the data obtained, there is a thermodynamical possibility to use partial dehydrated magnesium chloride hydrates as an absorbance to clean water vapor contained in bischophite dehydration equipment and let the protection gas HCl recycle in the fluid bed reaction system.

  12. Electricity, water, and natural gas consumption of a residential house in Canada from 2012 to 2014

    Science.gov (United States)

    Makonin, Stephen; Ellert, Bradley; Bajić, Ivan V.; Popowich, Fred

    2016-06-01

    With the cost of consuming resources increasing (both economically and ecologically), homeowners need to find ways to curb consumption. The Almanac of Minutely Power dataset Version 2 (AMPds2) has been released to help computational sustainability researchers, power and energy engineers, building scientists and technologists, utility companies, and eco-feedback researchers test their models, systems, algorithms, or prototypes on real house data. In the vast majority of cases, real-world datasets lead to more accurate models and algorithms. AMPds2 is the first dataset to capture all three main types of consumption (electricity, water, and natural gas) over a long period of time (2 years) and provide 11 measurement characteristics for electricity. No other such datasets from Canada exist. Each meter has 730 days of captured data. We also include environmental and utility billing data for cost analysis. AMPds2 data has been pre-cleaned to provide for consistent and comparable accuracy results amongst different researchers and machine learning algorithms.

  13. Electricity, water, and natural gas consumption of a residential house in Canada from 2012 to 2014.

    Science.gov (United States)

    Makonin, Stephen; Ellert, Bradley; Bajić, Ivan V; Popowich, Fred

    2016-06-07

    With the cost of consuming resources increasing (both economically and ecologically), homeowners need to find ways to curb consumption. The Almanac of Minutely Power dataset Version 2 (AMPds2) has been released to help computational sustainability researchers, power and energy engineers, building scientists and technologists, utility companies, and eco-feedback researchers test their models, systems, algorithms, or prototypes on real house data. In the vast majority of cases, real-world datasets lead to more accurate models and algorithms. AMPds2 is the first dataset to capture all three main types of consumption (electricity, water, and natural gas) over a long period of time (2 years) and provide 11 measurement characteristics for electricity. No other such datasets from Canada exist. Each meter has 730 days of captured data. We also include environmental and utility billing data for cost analysis. AMPds2 data has been pre-cleaned to provide for consistent and comparable accuracy results amongst different researchers and machine learning algorithms.

  14. Influence of frame inelasticity on poroviscoelastic reflections from a gas-water contact

    Science.gov (United States)

    Zhou, Rui; Chesnokov, Evgeny; Brown, Raymon

    2016-01-01

    As a natural extension of Biot theory, poroviscoelasticity is more comprehensive. The only difference between them is frame inelasticity, which influences wave dispersion, attenuation, reflection, and transmission. Hence we compute the influence, which uses the data of typical sand with gas and water saturation in the Gulf of Mexico with four values of frame inelasticity. The graphically illustrated results show that frame inelasticity has a small influence on the dispersion of P1- and S-waves and almost no influence on the dispersion of P2-wave. The frame inelasticity's influence on the P1- and S-wave attenuation is substantial with only a relatively small impact on the P2-wave attenuation. In some frequency and incident-angle ranges, frame inelasticity's influence on the reflection and transmission coefficients is considerable.

  15. Evaluating the Feasibility of Using Produced Water from Oil and Natural Gas Production to Address Water Scarcity in California’s Central Valley

    Directory of Open Access Journals (Sweden)

    Measrainsey Meng

    2016-12-01

    Full Text Available The current California drought has reduced freshwater availability, creating tensions between water users across the state. Although over 518 million m 3 of water were produced during fossil fuel production in California in 2014, the majority was disposed into Class II injection wells. There have been few attempts to assess the feasibility of using produced water for beneficial purposes, due in part to the difficulties of accessing, synthesizing and analyzing data regarding produced water quality and quantity. This study addresses this gap and provides a techno-economic assessment of upgrading produced water from California’s oil and natural gas activities and moving it to adjacent water-stressed regions. Results indicate that the four population centers facing the greatest water shortage risk are located in the Central Valley within a 161 km (100 mile radius of 230 million m 3 of total treatable produced water. This volume can supply up to one million people-years worth of potable water. The cost of desalinating and transporting this water source is comparable in magnitude to some agricultural and local public water supplies and is substantially lower than bottled water. Thus, utilizing reverse osmosis to treat produced water might be a feasible solution to help relieve water scarcity in some drought-stricken regions of California.

  16. An automatic flux chamber for investigating gas flux at water - air interfaces

    Science.gov (United States)

    Duc, N. T.; Silverstein, S.; Lundmark, L.; Reyier, H.; Crill, P. M.; Bastviken, D.

    2011-12-01

    Aquatic ecosystems are major sources of greenhouse gases (GHG) and representative measurements of GHG fluxes from aquatic ecosystems to the atmosphere are vital in climate related biogeochemistry. One of the most important fluxes, ebullition (bubble flux) of methane (CH4) is episodic, with large fluxes during short time periods. To properly capture such fluxes long term measurement approaches are necessary which is labor intensive for manual flux chamber based methods, or require expensive equipment with e.g. eddy correlation methods. An inexpensive and easily mobile automatic flux chamber for long-term measurements has been designed to approach these drawbacks. This device includes a flux chamber, with a controller/datalogger, valves, a pump, a 12 V battery and a solar cell. Sensors used so far record CH4 concentration in the chamber headspace, temperature in water and air, barometric pressure. Other sensors for e.g. CO2 and weather variables can be attached. The unit can be programmed to measure in situ accumulation of gas in the chamber and also to collect gas samples in an array of sample bottles for subsequent analysis in the laboratory. Simultaneous deployment of many such units represent a cost efficient and easily managed solution for local long term flux monitoring.

  17. Modeling and Analysis of the Reverse Water Gas Shift Process for In-Situ Propellant Production

    Science.gov (United States)

    Whitlow, Jonathan E.

    2000-01-01

    This report focuses on the development of mathematical models and simulation tools developed for the Reverse Water Gas Shift (RWGS) process. This process is a candidate technology for oxygen production on Mars under the In-Situ Propellant Production (ISPP) project. An analysis of the RWGS process was performed using a material balance for the system. The material balance is very complex due to the downstream separations and subsequent recycle inherent with the process. A numerical simulation was developed for the RWGS process to provide a tool for analysis and optimization of experimental hardware, which will be constructed later this year at Kennedy Space Center (KSC). Attempts to solve the material balance for the system, which can be defined by 27 nonlinear equations, initially failed. A convergence scheme was developed which led to successful solution of the material balance, however the simplified equations used for the gas separation membrane were found insufficient. Additional more rigorous models were successfully developed and solved for the membrane separation. Sample results from these models are included in this report, with recommendations for experimental work needed for model validation.

  18. Gas-Microjet Reactive Scattering: Collisions of HCl and DCl with Cool Salty Water.

    Science.gov (United States)

    Faust, Jennifer A; Sobyra, Thomas B; Nathanson, Gilbert M

    2016-02-18

    Liquid microjets provide a powerful means to investigate reactions of gases with salty water in vacuum while minimizing gas-vapor collisions. We use this technique to explore the fate of gaseous HCl and DCl molecules impinging on 8 molal LiCl and LiBr solutions at 238 K. The experiments reveal that HCl or DCl evaporate infrequently if they become thermally accommodated at the surface of either solution. In particular, we observe minimal thermal desorption of HCl following HCl collisions and no distinct evidence for rapid, interfacial DCl→HCl exchange following DCl collisions. These results imply that surface thermal motions are not generally strong enough to propel momentarily trapped HCl or DCl back into the gas phase before they ionize and disappear into solution. Instead, only HCl and DCl molecules that scatter directly from the surface escape entry. These recoiling molecules transfer less energy upon collision to LiBr/H2O than to LiCl/H2O, reflecting the heavier mass of Br(-) than of Cl(-) in the interfacial region.

  19. Microbial electrodialysis cell for simultaneous water desalination and hydrogen gas production.

    Science.gov (United States)

    Mehanna, Maha; Kiely, Patrick D; Call, Douglas F; Logan, Bruce E

    2010-12-15

    A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m(3) H(2)/m(3) d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements.

  20. Advanced gasifier and water gas shift technologies for low cost coal conversion to high hydrogen syngas

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Andrew Kramer [Gas Technology Inst., Des Plaines, IL (United States)

    2016-09-30

    The Gas Technology Institute (GTI) and team members RTI International (RTI), Coanda Research and Development, and Nexant, are developing and maturing a portfolio of technologies to meet the United States Department of Energy (DOE) goals for lowering the cost of producing high hydrogen syngas from coal for use in carbon capture power and coal-to-liquids/chemicals. This project matured an advanced pilot-scale gasifier, with scalable and commercially traceable components, to readiness for use in a first-of-a-kind commercially-relevant demonstration plant on the scale of 500-1,000 tons per day (TPD). This was accomplished through cold flow simulation of the gasifier quench zone transition region at Coanda and through an extensive hotfire gasifier test program on highly reactive coal and high ash/high ash fusion temperature coals at GTI. RTI matured an advanced water gas shift process and catalyst to readiness for testing at pilot plant scale through catalyst development and testing, and development of a preliminary design basis for a pilot scale reactor demonstrating the catalyst. A techno-economic analysis was performed by Nexant to assess the potential benefits of the gasifier and catalyst technologies in the context of power production and methanol production. This analysis showed an 18%reduction in cost of power and a 19%reduction in cost of methanol relative to DOE reference baseline cases.

  1. Natural gas purification using a porous coordination polymer with water and chemical stability.

    Science.gov (United States)

    Duan, Jingui; Jin, Wanqin; Krishna, Rajamani

    2015-05-04

    Porous coordination polymers (PCPs), constructed by bridging the metals or clusters and organic linkers, can provide a functional pore environment for gas storage and separation. But the rational design for identifying PCPs with high efficiency and low energy cost remains a challenge. Here, we demonstrate a new PCP, [(Cu4Cl)(BTBA)8·(CH3)2NH2)·(H2O)12]·xGuest (PCP-33⊃guest), which shows high potential for purification of natural gas, separation of C2H2/CO2 mixtures, and selective removal of C2H2 from C2H2/C2H4 mixtures at ambient temperature. The lower binding energy of the framework toward these light hydrocarbons indicates the reduced net costs for material regeneration, and meanwhile, the good water and chemical stability of it, in particular at pH = 2 and 60 °C, shows high potential usage under some harsh conditions. In addition, the adsorption process and effective site for separation was unravelled by in situ infrared spectroscopy studies.

  2. Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

    KAUST Repository

    Mehanna, Maha

    2010-12-15

    A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

  3. Single-stage temperature-controllable water gas shift reactor with catalytic nickel plates

    Science.gov (United States)

    Park, Jin-Woo; Lee, Sung-Wook; Lee, Chun-Boo; Park, Jong-Soo; Lee, Dong-Wook; Kim, Sung-Hyun; Kim, Sung-Soo; Ryi, Shin-Kun

    2014-02-01

    In this study, a microstructured reactor with catalytic nickel plates is newly designed and developed for proper heat management in an exothermic water gas shift WGS reaction. The reactor is designed to increase the reactor capacity simply by numbering-up a set of a catalyst layers and heat exchanger layers. The WGS reactor is built up with two sets of a catalyst layers and heat exchanger layers. The performance of the reactor is verified by WGS testing with the variation of the furnace temperatures, gas hourly space velocity (GHSV) and coolant (N2) flow rate. At a GHSV of 10,000 h-1, CO conversion reaches the equilibrium value with a CH4 selectivity of ≤0.5% at the furnace temperature of ≥375 °C. At high GHSV (40,000 h-1), CO conversion decreases considerably because of the heat from the exothermic WGS reaction at a large reactants mass. By increasing the coolant flow rate, the heat from the WGS reaction is properly managed, leading an increase of the CO conversion to the equilibrium value at GHSV of 40,000 h-1.

  4. Disposal/recovery options for brine waters from oil and gas production in New York State. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, M.R.; Atkinson, J.F.; Bunn, M.D.; Hodge, D.S.

    1996-03-01

    Produced water from oil and gas operations, or brine as it is typically referred, may be characterized as being highly saline, with total dissolved solids greater than 100 g/L. If these bribes are disposed improperly there may be severe adverse environmental effects. Thus, it is important that brine be disposed using environmentally sound methods. Unfortunately, costs for the disposal of brine water are a significant burden to oil and gas producers in New York State. These costs and the relatively low market price of oil and natural gas have contributed to the decline in gas and oil production in New York State during the past 10 years. The objectives of this study were to evaluate new and existing options for brine disposal in New York State, examine the technical and economic merits of these options, and assess environmental impacts associated with each option. Two new disposal options investigated for New York State oil and gas producers included construction of a regional brine treatment facility to treat brine prior to discharge into a receiving water and a salt production facility that utilizes produced water as a feed stock. Both options are technically feasible; however, their economic viability depends on facility size and volume of brine treated.

  5. The Influence of Extreme Water Pulses on Greenhouse Gas Emissions from Soils

    Science.gov (United States)

    Petrakis, S.; Vargas, R.; Seyfferth, A.; Kan, J.; Inamdar, S. P.

    2015-12-01

    Anthropogenic activity increasing the amount of radiatively active gases, or Greenhouse Gases (GHGs) in the earth's atmosphere has led to shifts in weather patterns. Climate models predict the occurrence of large storms may increase in frequency and intensity in the mid-Atlantic region. Knowing that extreme precipitation events are rare, testing the influence of large water pulses across different soil types within an ecosystem is challenging. Large additions of water could promote or inhibit microbial activity, and change soil chemistry within a few days. Rapid changes in soil moisture lead to shifts in the behavior of soils as either sinks or sources of several GHGs (i.e., CO2, CH4 and N2O). Unfortunately, it is still unclear how rewetting events could impact the magnitude of GHG fluxes and how changing soil chemical parameters influence these responses. An experiment was designed to test the influence of extreme repeated water pulses on GHG fluxes from four different soils, representing key topographic locations within a watershed in the Piedmont region (i.e., forested upland, forested lowland, creek, wetland). Intact soil cores from these four soil types were kept under constant temperature (22oC) and we measured their responses to extreme water pulses. We continuously (hourly resolution) measured CO2, CH4 and N2O fluxes using a LI-8100A (Licor, Lincoln, NE) multiplexed system coupled to a Picarro G2508 (Picarro, Santa Clara, CA). Furthermore, we used a rhizolysimeter for porewater extraction to measure pH, redox, and water chemistry throughout the experiment. We hypothesized that repeated extreme water pulses would result in non-linear responses of GHG flux magnitudes and dynamics, and these dynamics would relate to changes in soil chemistry. We found that soil moisture alone could not explain the dynamics of GHG fluxes, but these extreme water pulses influenced the overall temporal patterns of all GHGs across all soil types. We also examined the 100 year

  6. Wetland treatment of oil and gas well waste waters. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kadlec, R.; Srinivasan, K.

    1995-08-01

    Constructed wetlands are small on-site systems that possess three of the most desirable components of an industrial waste water treatment scheme: low cost, low maintenance and upset resistance. The main objective of the present study is to extend the knowledge base of wetland treatment systems to include processes and substances of particular importance to small, on-site systems receiving oil and gas well wastewaters. A list of the most relevant and comprehensive publications on the design of wetlands for water quality improvement was compiled and critically reviewed. Based on our literature search and conversations with researchers in the private sector, toxic organics such as Phenolics and b-naphthoic acid, (NA), and metals such as CU(II) and CR(VI) were selected as target adsorbates. A total of 90 lysimeters equivalent to a laboratory-scale wetland were designed and built to monitor the uptake and transformation of toxic organics and the immobilization of metal ions. Studies on the uptake of toxic organics such as phenol and b-naphthoic acid (NA) and heavy metals such as Cu(II) and Cr(VI), the latter two singly or as non-stoichiometric mixtures by laboratory-type wetlands (LWs) were conducted. These LWs were designed and built during the first year of this study. A road map and guidelines for a field-scale implementation of a wetland system for the treatment of oil and gas wastewaters have been suggested. Two types of wetlands, surface flow (SF) and sub surface flow (SSF), have been considered, and the relative merits of each configuration have been reviewed.

  7. Geochemical mapping of magmatic gas water rock interactions in the aquifer of Mount Etna volcano

    Science.gov (United States)

    Brusca, L.; Aiuppa, A.; D'Alessandro, W.; Parello, F.; Allard, P.; Michel, A.

    2001-08-01

    Systematic analysis of major and minor elements in groundwaters from springs and wells on the slopes of Mt. Etna in 1995-1998 provides a detailed geochemical mapping of the aquifer of the volcano and of the interactions between magmatic gas, water bodies and their host rocks. Strong spatial correlations between the largest anomalies in pCO 2 (pH and alkalinity) K, Rb, Mg, Ca and Sr suggest a dominating control by magmatic gas (CO 2) and consequent basalt leaching by acidified waters of the shallow (meteoric) Etnean aquifer. Most groundwaters displaying this magmatic-type interaction discharge within active faulted zones on the S-SW and E lower flanks of the volcanic pile, but also in a newly recognised area on the northern flank, possibly tracking a main N-S volcano-tectonic structure. In the same time, the spatial distribution of T°C, TDS, Na, Li, Cl and B allows us to identify the existence of a deeper thermal brine with high salinity, high content of B, Cl and gases (CO 2, H 2S, CH 4) and low K/Na ratio, which is likely hosted in the sedimentary basement. This hot brine reaches the surface only at the periphery of the volcano near the Village of Paternò, where it gives rise to mud volcanoes called "Salinelle di Paternò". However, the contribution of similar brines to shallower groundwaters is also detected in other sectors to the W (Bronte, Maletto), SW (Adrano) and SE (Acireale), suggesting its possible widespread occurrence beneath Etna. This thermal brine is also closely associated with hydrocarbon fields all around the volcano and its rise, generally masked by the high outflow of the shallow aquifer, may be driven by the ascent of mixed sedimentary-magmatic gases through the main faults cutting the sedimentary basement.

  8. Real-time surrogate analysis for potential oil and gas contamination of drinking water resources

    Science.gov (United States)

    Son, Ji-Hee; Carlson, Kenneth H.

    2015-09-01

    Public concerns related to the fast-growing shale oil and gas industry have increased during recent years. The major concern regarding shale gas production is the potential of fracturing fluids being injected into the well or produced fluids flowing out of the well to contaminate drinking water resources such as surface water and groundwater. Fracturing fluids contain high total dissolved solids (TDS); thus, changes in TDS concentrations in groundwater might indicate influences of fracturing fluids. An increase of methane concentrations in groundwater could also potentially be due to hydraulic fracturing activities. To understand the possible contamination of groundwater by fracturing activities, real-time groundwater monitoring is being implemented in the Denver-Julesburg basin of northeast Colorado. A strategy of monitoring of surrogate parameters was chosen instead of measuring potential contaminants directly, an approach that is not cost effective or operationally practical. Contaminant surrogates of TDS and dissolved methane were proposed in this study, and were tested for correlation and data distribution with laboratory experiments. Correlations between TDS and electrical conductivity (EC), and between methane contamination and oxidation-reduction potential (ORP) were strong at low concentrations of contaminants (1 mg/L TDS and 0.3 mg/L CH4). Dissolved oxygen (DO) was only an effective surrogate at higher methane concentrations (≥2.5 mg/L). The results indicated that EC and ORP are effective surrogates for detecting concentration changes of TDS and methane, respectively, and that a strategy of monitoring for easy to measure parameters can be effective detecting real-time, anomalous behavior relative to a predetermined baseline.

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

    OpenAIRE

    Tarafder, Shamsul Abedin

    2007-01-01

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

  10. The functional potential of microbial communities in hydraulic fracturing source water and produced water from natural gas extraction characterized by metagenomic sequencing.

    Science.gov (United States)

    Mohan, Arvind Murali; Bibby, Kyle J; Lipus, Daniel; Hammack, Richard W; Gregory, Kelvin B

    2014-01-01

    Microbial activity in produced water from hydraulic fracturing operations can lead to undesired environmental impacts and increase gas production costs. However, the metabolic profile of these microbial communities is not well understood. Here, for the first time, we present results from a shotgun metagenome of microbial communities in both hydraulic fracturing source water and wastewater produced by hydraulic fracturing. Taxonomic analyses showed an increase in anaerobic/facultative anaerobic classes related to Clostridia, Gammaproteobacteria, Bacteroidia and Epsilonproteobacteria in produced water as compared to predominantly aerobic Alphaproteobacteria in the fracturing source water. The metabolic profile revealed a relative increase in genes responsible for carbohydrate metabolism, respiration, sporulation and dormancy, iron acquisition and metabolism, stress response and sulfur metabolism in the produced water samples. These results suggest that microbial communities in produced water have an increased genetic ability to handle stress, which has significant implications for produced water management, such as disinfection.

  11. A perspective on cost-effectiveness of greenhouse gas reduction solutions in water distribution systems

    Science.gov (United States)

    Hendrickson, Thomas P.; Horvath, Arpad

    2014-01-01

    Water distribution systems (WDSs) face great challenges as aging infrastructures require significant investments in rehabilitation, replacement, and expansion. Reducing environmental impacts as WDSs develop is essential for utility managers and policy makers. This study quantifies the existing greenhouse gas (GHG) footprint of common WDS elements using life-cycle assessment (LCA) while identifying the greatest opportunities for emission reduction. This study addresses oversights of the related literature, which fails to capture several WDS elements and to provide detailed life-cycle inventories. The life-cycle inventory results for a US case study utility reveal that 81% of GHGs are from pumping energy, where a large portion of these emissions are a result of distribution leaks, which account for 270 billion l of water losses daily in the United States. Pipe replacement scheduling is analyzed from an environmental perspective where, through incorporating leak impacts, a tool reveals that optimal replacement is no more than 20 years, which is in contrast to the US average of 200 years. Carbon abatement costs (CACs) are calculated for different leak reduction scenarios for the case utility that range from -130 to 35 t-1 CO2(eq). Including life-cycle modeling in evaluating pipe materials identified polyvinyl chloride (PVC) and cement-lined ductile iron (DICL) as the Pareto efficient options, however; utilizing PVC presents human health risks. The model developed for the case utility is applied to California and Texas to determine the CACs of reducing leaks to 5% of distributed water. For California, annual GHG savings from reducing leaks alone (3.4 million tons of CO2(eq)) are found to exceed California Air Resources Board’s estimate for energy efficiency improvements in the state’s water infrastructure.

  12. Ab Initio Studies on the Preferred Site of Protonation in Cytisine in the Gas Phase and Water

    Directory of Open Access Journals (Sweden)

    Małgorzata Darowska

    2005-01-01

    Full Text Available Abstract: Ab initio calculations (HF, MP2, DFT for isolated and PCM for solvated molecules were performed for cytisine (1 and its model compounds: N-methyl-2-pyridone (2 and piperidine (3. Among three heteroatomic functions (carbonyl oxygen, pyridone and piperidine nitrogens considered as the possible sites of protonation in 1, surprisingly the carbonyl oxygen takes preferentially the proton in the gas phase whereas in water the piperidine nitrogen is firstly protonated. For model compounds, the piperidine nitrogen in 3 is more basic than the carbonyl oxygen in 2 in both, the gas phase and water.

  13. Water and gas geochemistry of the Calatrava Volcanic Province (CVP) hydrothermal system (Ciudad Real, central Spain)

    Science.gov (United States)

    Vaselli, Orlando; Nisi, Barbara; Tassi, Franco; Giannini, Luciano; Grandia, Fidel; Darrah, Tom; Capecchiacci, Francesco; del Villar, Pèrez

    2013-04-01

    An extensive geochemical and isotopic investigation was carried out in the water and gas discharges of the Late Miocene-Quaternary Calatrava Volcanic Province (CVP) (Ciudad Real, Spain) with the aim reconstruct the fluid circulation in the area. CVP consists of a series of scattered (monogenetic) vents from where alkaline lava flows and pyroclastic deposits formed in two different periods. The first stage (8.7-6.4 Ma) mainly included ultra-potassic mafic extrusives, whilst the second stage (4.7-1.75 Ma) prevalently originated alkaline and ultra-alkaline volcanics. Both stages were followed by a volcanic activity that extended up to 1.3 and 0.7 Ma, respectively. This area can likely be regarded as one of the most important emitting zones of CO2 in the whole Peninsular Spain along with that of Selva-Emporda in northeastern Spain (Cataluña) and it can be assumed as one of the best examples of natural analogues of CO2 leakages in Spain. This latter aspect is further evidenced by the relatively common water-gas blast events that characterize the CCVF. In the last few years the presence of a CO2-pressurized reservoir at a relatively shallow level as indeed caused several small-sized explosion particularly during the drilling of domestic wells. The fluid discharging sites are apparently aligned along well-defined directions: NW-SE and NNW-SSE and subordinately, ENE-WSW, indicating a clear relationship between the thermal discharges and the volcanic centers that also distribute along these lineaments. The CVP waters are mostly hypothermal (up to 33 °C) and are generally Mg(Ca)-HCO3 in composition and occasionally show relatively high concentrations of Fe and Mn, with pH and electrical conductivity down to 5.5 and up to 6.5 mS/cm, respectively. The oxygen and hydrogen isotopes suggest a meteoric origin for these waters. The mantle source of these volcanic products is apparently preserved in the many CO2-rich (up to 990,000 mmol/mol) gas discharges that characterize CVP

  14. Flow resistance reduction of coal water slurry through gas phase addition

    Directory of Open Access Journals (Sweden)

    Robak Jolanta

    2016-01-01

    Full Text Available One of the main advantages of coal water slurry fuel (CWS is a physical form that allows, among others, their transfer by pipelines over long distances. For this form of transport actions towards reducing the flow resistance of the transmitted medium are important. One of the treatments leading to reduction in the flow resistance of suspensions is to introduce gas into the stream of flowing slurry. The goal of that action is to either loosen the structure of densely packed grains or increase the velocity of the suspension. The paper presents the flow resistance of CWS in a horizontal pipeline and the effect of addition of the gas phase on the resistance level. The investigation was carried out with the use of a research stand enabling to measure the flow resistance of the multiphase/multicomponent systems. The measured diameter and length of sections were respectively: 0.03 and 2 m. The coal-water slurries (based on steam coals with concentration of dry coal in the range of 51 do 60% obtained by wet milling in a drum mill were used. During the tests, the following parameters were measured: slurry flow rate, air flow rate, temperature and pressure difference in inlet and outlet of the measured section. The volume flow rate of slurry fuel was in the range of 30 to 110 dm3/min while the volume flow rate of air was from 0.15 to 4 m3/h. Based on the obtained results, the slurry flow resistance as a function of the flow rate and share of introduced air was evaluated. The performed research allowed for assessment of flow resistance reduction condition and to determine the pipe flow curves for different temperatures. It was found that the effect of reducing the flow resistance of the coal slurry by introducing gas into the flow tube depended on the volumetric flow rate, and thus the linear velocity of the slurry. Under the experimental condition, this effect only occurred at low flow rates (30 - 50 dm3/min and low temperature of the suspension. The

  15. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    T. Schirber, B. Schoenbauer

    2017-06-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high-performance water heaters difficult to justify economically. However, recent advancements in high-performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high-efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands.

  16. Effects of porosity distribution variation on the liquid water flux through gas diffusion layers of PEM fuel cells

    Science.gov (United States)

    Zhan, Zhigang; Xiao, Jinsheng; Li, Dayong; Pan, Mu; Yuan, Runzhang

    Flooding of the membrane electrode assembly (MEA) and dehydrating of the polymer electrolyte membrane have been the key problems to be solved for polymer electrolyte membrane fuel cells (PEMFCs). So far, almost no papers published have focused on studies of the liquid water flux through differently structured gas diffusion layers (GDLs). For gas diffusion layers including structures of uniform porosity, changes in porosity (GDL with microporous layer (MPL)) and gradient change porosity, using a one-dimensional model, the liquid saturation distribution is analyzed based on the assumption of a fixed liquid water flux through the GDL. And then the liquid water flux through the GDL is calculated based on the assumption of a fixed liquid saturation difference between the interfaces of the catalyst layer/GDL and the GDL/gas channel. Our results show that under steady-state conditions, the liquid water flux through the GDL increases as contact angle and porosity increase and as the GDL thickness decreases. When a MPL is placed between the catalyst layer and the GDL, the liquid saturation is redistributed across the MPL and GDL. This improves the liquid water draining performance. The liquid water flux through the GDL increases as the MPL porosity increases and the MPL thickness decreases. When the total thickness of the GDL and MPL is kept constant and when the MPL is thinned to 3 μm, the liquid water flux increases considerably, i.e. flooding of MEA is difficult. A GDL with a gradient of porosity is more favorable for liquid water discharge from catalyst layer into the gas channel; for the GDLs with the same equivalent porosity, the larger the gradient is, the more easily the liquid water is discharged. Of the computed cases, a GDL with a linear porosity 0.4 x + 0.4 is the best.

  17. Water usage for natural gas production through hydraulic fracturing in the United States from 2008 to 2014.

    Science.gov (United States)

    Chen, Huan; Carter, Kimberly E

    2016-04-01

    Hydraulic fracturing has promoted the exploitation of shale oil and natural gas in the United States (U.S.). However, the large amounts of water used in hydraulic fracturing may constrain oil and natural gas production in the shale plays. This study surveyed the amounts of freshwater and recycled produced water used to fracture wells from 2008 to 2014 in Arkansas, California, Colorado, Kansas, Louisiana, Montana, North Dakota, New Mexico, Ohio, Oklahoma, Pennsylvania, Texas, West Virginia, and Wyoming. Results showed that the annual average water volumes used per well in most of these states ranged between 1000 m(3) and 30,000 m(3). The highest total amount of water was consumed in Texas with 457.42 Mm(3) of water used to fracture 40,521 wells, followed by Pennsylvania with 108.67 Mm(3) of water used to treat 5127 wells. Water usages ranged from 96.85 Mm(3) to 166.10 Mm(3) annually in Texas from 2012 to 2014 with more than 10,000 wells fractured during that time. The percentage of water used for hydraulic fracturing in each state was relatively low compared to water usages for other industries. From 2009 to 2014, 6.55% (median) of the water volume used in hydraulic fracturing contained recycled produced water or recycled hydraulic fracturing wastewater. 10.84% (median) of wells produced by hydraulic fracturing were treated with recycled produced water. The percentage of wells where recycled wastewater was used was lower, except in Ohio and Arkansas, where more than half of the wells were fractured using recycled produced water. The median recycled wastewater volume in produced wells was 7127 m(3) per well, more than half the median value in annual water used per well 11,259 m(3). This indicates that, for wells recycling wastewater, more than half of their water use consisted of recycled wastewater.

  18. Water Transport in the Micro Porous Layer and Gas Diffusion Layer of a Polymer Electrolyte Fuel Cell

    Science.gov (United States)

    Qin, C.; Hassanizadeh, S. M.

    2015-12-01

    In this work, a recently developed dynamic pore-network model is presented [1]. The model explicitly solves for both water pressure and capillary pressure. A semi-implicit scheme is used in updating water saturation in each pore body, which considerably increases the numerical stability at low capillary number values. Furthermore, a multiple-time-step algorithm is introduced to reduce the computational effort. A number of case studies of water transport in the micro porous layer (MPL) and gas diffusion layer (GDL) are conducted. We illustrate the role of MPL in reducing water flooding in the GDL. Also, the dynamic water transport through the MPL-GDL interface is explored in detail. This information is essential to the reduced continua model (RCM), which was developed for multiphase flow through thin porous layers [2, 3]. C.Z. Qin, Water transport in the gas diffusion layer of a polymer electrolyte fuel cell: dynamic pore-network modeling, J Electrochimical. Soci., 162, F1036-F1046, 2015. C.Z. Qin and S.M. Hassanizadeh, Multiphase flow through multilayers of thin porous media: general balance equations and constitutive relationships for a solid-gas-liquid three-phase system, Int. J. Heat Mass Transfer, 70, 693-708, 2014. C.Z. Qin and S.M. Hassanizadeh, A new approach to modeling water flooding in a polymer electrolyte fuel cell, Int. J. Hydrogen Energy, 40, 3348-3358, 2015.

  19. The Functional Potential of Microbial Communities in Hydraulic Fracturing Source Water and Produced Water from Natural Gas Extraction Characterized by Metagenomic Sequencing

    OpenAIRE

    Arvind Murali Mohan; Bibby, Kyle J.; Daniel Lipus; Hammack, Richard W.; Gregory, Kelvin B

    2014-01-01

    Microbial activity in produced water from hydraulic fracturing operations can lead to undesired environmental impacts and increase gas production costs. However, the metabolic profile of these microbial communities is not well understood. Here, for the first time, we present results from a shotgun metagenome of microbial communities in both hydraulic fracturing source water and wastewater produced by hydraulic fracturing. Taxonomic analyses showed an increase in anaerobic/facultative anaerobi...

  20. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    OpenAIRE

    Dietmar Gerteisen; Robert Alink

    2013-01-01

    In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM) fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL) structure and the transitions from the paths to the subsequent ...

  1. Quantitative Variation in Water-Use Efficiency across Water Regimes and Its Relationship with Circadian, Vegetative, Reproductive, and Leaf Gas-Exchange Traits

    Institute of Scientific and Technical Information of China (English)

    Christine E. Edwards; Brent E. Ewers; C. Robertson McClung; Ping Lou; Cynthia Weinig

    2012-01-01

    Drought limits light harvesting,resulting in lower plant growth and reproduction.One trait important for plant drought response is water-use efficiency (WUE).We investigated (1) how the joint genetic architecture of WUE,reproductive characters,and vegetative traits changed across drought and well-watered conditions,(2) whether traits with distinct developmental bases (e.g.leaf gas exchange versus reproduction) differed in the environmental sensitivity of their genetic architecture,and (3) whether quantitative variation in circadian period was related to drought response in Brassica rapa.Overall,WUE increased in drought,primarily because stomatal conductance,and thus water loss,declined more than carbon fixation.Genotypes with the highest WUE in drought expressed the lowest WUE in well-watered conditions,and had the largest vegetative and floral organs in both treatments.Thus,large changes in WUE enabled some genotypes to approach vegetative and reproductive trait optima across environments.The genetic architecture differed for gas-exchange and vegetative traits across drought and well-watered conditions,but not for floral traits.Correlations between circadian and leaf gas-exchange traits were significant but did not vary across treatments,indicating that circadian period affects physiological function regardless of water availability.These results suggest that WUE is important for drought tolerance in Brassica rapa and that artificial selection for increased WUE in drought will not result in maladaptive expression of other traits that are correlated with WUE.

  2. Depressurization and two-phase flow of water containing high levels of dissolved nitrogen gas

    Science.gov (United States)

    Simoneau, R. J.

    1981-01-01

    Depressurization of water containing various concentrations of dissolved nitrogen gas was studied. In a nonflow depressurization experiment, water with very high nitrogen content was depressurized at rates from 0.09 to 0.50 MPa per second and a metastable behavior which was a strong function of the depressurization rate was observed. Flow experiments were performed in an axisymmetric, converging diverging nozzle, a two dimensional, converging nozzle with glass sidewalls, and a sharp edge orifice. The converging diverging nozzle exhibited choked flow behavior even at nitrogen concentration levels as low as 4 percent of the saturation level. The flow rates were independent of concentration level. Flow in the two dimensional, converging, visual nozzle appeared to have a sufficient pressure drop at the throat to cause nitrogen to come out of solution, but choking occurred further downstream. The orifice flow motion pictures showed considerable oscillation downstream of the orifice and parallel to the flow. Nitrogen bubbles appeared in the flow at back pressures as high as 3.28 MPa, and the level at which bubbles were no longer visible was a function of nitrogen concentration.

  3. The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

    Science.gov (United States)

    Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

    2012-10-15

    Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours.

  4. Ternary System of Fe-based Ionic Liquid, Ethanol and Water for Wet Flue Gas Desulfurization

    Institute of Scientific and Technical Information of China (English)

    解美莹; 李沛沛; 郭惠锋; 高丽霞; 余江

    2012-01-01

    Fe-based ionic liquid (Fe-IL) was synthesized by mixing FeCl3·6H2O and 1-butyl-3-methylimidazolium chloride [Bmim]C1 in this paper. The phase diagram of a ternary Fe-IL, ethanol and water system was investigated to construct a ternary desulfurization solution for wet flue gas desulfurization. The effects of flow rate and concentration of SO2, reaction temperature, pH and Fe-IL fraction in aqueous desulfurization solution on the desulfiariza- tion efficiency were investigated. The results shows that the best composition of ternary desulfurization solution of Fe-IL, ethanol and water is 1 : 1.5 : 3 by volume ratio, and pH should be controlled at 2.0. Under such conditions, a desulfurization rate greater than 90% could be obtained. The product of sulfuric acid had inhibition effect on the wet desulfurization process. With applying this new ternary desulfurization solution, not only the catalyst Fe-IL can be recycled and reused, but also the product sulfuric acid can be separated directly from the ternary desulfurization system.

  5. Biogenic methane production in formation waters from a large gas field in the North Sea.

    Science.gov (United States)

    Gray, Neil D; Sherry, Angela; Larter, Stephen R; Erdmann, Michael; Leyris, Juliette; Liengen, Turid; Beeder, Janiche; Head, Ian M

    2009-05-01

    Methanogenesis was investigated in formation waters from a North Sea oil rimmed gas accumulation containing biodegraded oil, which has not been subject to seawater injection. Activity and growth of hydrogenotrophic methanogens was measured but acetoclastic methanogenesis was not detected. Hydrogenotrophic methanogens showed activity between 40 and 80 degrees C with a temperature optimum (ca. 70 degrees C) consistent with in situ reservoir temperatures. They were also active over a broad salinity range, up to and consistent with the high salinity of the waters (90 g l(-1)). These findings suggest the methanogens are indigenous to the reservoir. The conversion of H(2) and CO(2) to CH(4) in methanogenic enrichments was enhanced by the addition of inorganic nutrients and was correlated with cell growth. Addition of yeast extract also stimulated methanogenesis. Archaeal 16S rRNA gene sequences recovered from enrichment cultures were closely related to Methanothermobacter spp. which have been identified in other high-temperature petroleum reservoirs. It has recently been suggested that methanogenic oil degradation may be a major factor in the development of the world's heavy oils and represent a significant and ongoing process in conventional deposits. Although an oil-degrading methanogenic consortium was not enriched from these samples the presence and activity of communities of fermentative bacteria and methanogenic archaea was demonstrated. Stimulation of methanogenesis by addition of nutrients suggests that in situ methanogenic biodegradation of oil could be harnessed to enhance recovery of stranded energy assets from such petroleum systems.

  6. AQUEOUS TWO-PHASE GAS FLOATATION SPECTROPHOTOMETRIC DETERMINATION OF TRACE TETRACYCLINE IN ENVIRONMENTAL WATER SAMPLE

    Institute of Scientific and Technical Information of China (English)

    HOU Yanmin; YAN Yongsheng; LI Chunxiang; ZHAO Xiaojun; WANG Liang

    2008-01-01

    A green method for separating and enriching trace tetracycline (TC) in environment water by Aqueous Two-phase Gas Fioatation Spectrophotometry has been proposed, the principium was discussed.In this paper, the hydrophobic complex composed of Mg(Ⅱ) and TC was floated into organic phase under the optimal conditions: pH=10, the floatatlon equipment is home-made, n-propyl alcohol as the organic solvent, sodium chloride as the separating phase reagent.The data were obtained by spectrophotometry after floatatlon; The linear regression ,equation is A=2.33×105 C(mol/L)+0.2179, linear range is from 3.77×107mol/L to 6.32×105mol/L, respectively, with the correlation coefficient (r) better than 0.9997, relative recoveries is 99.7% to 100.3%, limit of detection was 4.29×10-8mol/L, The method can be applied to analyse the trace TC in water sample, the result is better.

  7. AQUEOUS TWO-PHASE GAS FLOATATION SPECTROPHOTOMETRIC DETERMINATION OF TRACE TETRACYCLINE IN ENVIRONMENTAL WATER SAMPLE

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A green method for separating and enriching trace tetracycline (TC) in environment water by Aqueous Two-phase Gas Floatation Spectrophotometry has been proposed, the principium was discussed. In this paper, the hydrophobic complex composed of Mg(II) and TC was floated into organic phase under the optimal conditions: pH=10, the floatation equipment is home-made, n-propyl alcohol as the organic solvent, sodium chloride as the separating phase reagent. The data were obtained by spectrophotometry after floatation; The linear regression equation is A=2.33×105C(mol/L)+0.2179, linear range is from 3.77×10-7mol/L to 6.32×10-5mol/L, respectively, with the correlation coefficient (r) better than 0.9997, relative recoveries is 99.7% to 100.3%, limit of detection was 4.29×10-8mol/L, The method can be applied to analyse the trace TC in water sample, the result is better.

  8. A mini review on the chemistry and catalysis of the water gas shift reaction

    CERN Document Server

    Zhao, Zhun

    2014-01-01

    Water gas shift (WGS) reaction is a chemical reaction in which carbon monoxide reacts with water vapor to form carbon dioxide and hydrogen. It is an important reaction industrially used in conjunction with steam reforming of hydrocarbons for the production of high purity hydrogen. Grenoble et al examined the roles of both active metals and metal oxide support on the kinetics of the WGS reaction. They found out that the turn over numbers of various Al2O3 supported transition metals decreased in the trend of Cu, Re, Co, Ru, Ni, Pt, Os, Au, Fe, Pd, Rh, and Ir, which corresponds nicely to the observed volcano shaped correlation between catalytic activities and respective CO adsorption heat. This is a strong indication that CO gets activated on the metal surface during the reaction and different metals have different activation energies. The authors also observed that the turn over number of Pt/Al2O3 was one order of magnitude higher than that of Pt/SiO2, indicating a strong support effect, which the authors ascri...

  9. Alternative sorptive extraction method for gas chromatography determination of halogenated anisoles in water and wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)], E-mail: qnisaac@usc.es; Rubi, E.; Bollain, M.H.; Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2007-09-05

    An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 h and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 {mu}L. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L{sup -1}, depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated.

  10. Microbial communities in flowback water impoundments from hydraulic fracturing for recovery of shale gas

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, Arvind Murali; Hartsock, Angela; Hammack, Richard W; Vidic, Radisav D; Gregory, Kelvin B

    2013-12-01

    Hydraulic fracturing for natural gas extraction from shale produces waste brine known as flowback that is impounded at the surface prior to reuse and/or disposal. During impoundment, microbial activity can alter the fate of metals including radionuclides, give rise to odorous compounds, and result in biocorrosion that complicates water and waste management and increases production costs. Here, we describe the microbial ecology at multiple depths of three flowback impoundments from the Marcellus shale that were managed differently. 16S rRNA gene clone libraries revealed that bacterial communities in the untreated and biocide-amended impoundments were depth dependent, diverse, and most similar to species within the taxa [gamma]-proteobacteria, [alpha]-proteobacteria, δ-proteobacteria, Clostridia, Synergistetes, Thermotogae, Spirochetes, and Bacteroidetes. The bacterial community in the pretreated and aerated impoundment was uniform with depth, less diverse, and most similar to known iodide-oxidizing bacteria in the [alpha]-proteobacteria. Archaea were identified only in the untreated and biocide-amended impoundments and were affiliated to the Methanomicrobia class. This is the first study of microbial communities in flowback water impoundments from hydraulic fracturing. The findings expand our knowledge of microbial diversity of an emergent and unexplored environment and may guide the management of flowback impoundments.

  11. Evaluating options for balancing the water-electricity nexus in California: Part 2--greenhouse gas and renewable energy utilization impacts.

    Science.gov (United States)

    Tarroja, Brian; AghaKouchak, Amir; Sobhani, Reza; Feldman, David; Jiang, Sunny; Samuelsen, Scott

    2014-11-01

    A study was conducted to compare the technical potential and effectiveness of different water supply options for securing water availability in a large-scale, interconnected water supply system under historical and climate-change augmented inflow and demand conditions. Part 2 of the study focused on determining the greenhouse gas and renewable energy utilization impacts of different pathways to stabilize major surface reservoir levels. Using a detailed electric grid model and taking into account impacts on the operation of the water supply infrastructure, the greenhouse gas emissions and effect on overall grid renewable penetration level was calculated for each water supply option portfolio that successfully secured water availability from Part 1. The effects on the energy signature of water supply infrastructure were found to be just as important as that of the fundamental processes for each option. Under historical (baseline) conditions, many option portfolios were capable of securing surface reservoir levels with a net neutral or negative effect on emissions and a benefit for renewable energy utilization. Under climate change augmented conditions, however, careful selection of the water supply option portfolio was required to prevent imposing major emissions increases for the system. Overall, this analysis provided quantitative insight into the tradeoffs associated with choosing different pathways for securing California's water supply.

  12. Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample.

    Science.gov (United States)

    Muraoka, Michihiro; Susuki, Naoko; Yamaguchi, Hiroko; Tsuji, Tomoya; Yamamoto, Yoshitaka

    2016-03-21

    Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

  13. Seasonal and diurnal characteristics of water soluble inorganic compounds in the gas and aerosol phase in the Zurich area

    Directory of Open Access Journals (Sweden)

    R. Fisseha

    2006-01-01

    Full Text Available Gas and aerosol samples were taken using a wet effluent diffusion denuder/aerosol collector (WEDD/AC coupled to ion chromatography (IC in the city of Zurich, Switzerland from August to September 2002 and in March 2003. Major water soluble inorganic ions; nitrate, sulfate, and nitrite were analyzed online with a time resolution of two hours for the gas and aerosol phase. The fraction of water soluble inorganic anions in PM10 varied from 15% in August to about 38% in March. Seasonal and diurnal variations of nitrate in the gas and aerosol phase were observed with more than 50% of the total nitrate in the gas phase during August and more than 80% of nitrate in the aerosol phase during March exceeding the concentration of sulfate by a factor of 2. Aerosol sulfate, on the other hand, did not show significant variability with season. However, in the gas phase, the SO2 concentration was 6.5 times higher in winter than in summer. Nitrous acid (HONO also showed a diurnal variation in both the gas and aerosol phase with the lowest concentration (0.2–0.6 µg/m3 in the afternoon. The primary pollutants, NO, CO and SO2 mixing ratios were often at their highest between 04:00–10:00 local time due to the build up of fresh vehicle emission under a nocturnal inversion.

  14. Numerical modelling of methane oxidation efficiency and coupled water-gas-heat reactive transfer in a sloping landfill cover.

    Science.gov (United States)

    Feng, S; Ng, C W W; Leung, A K; Liu, H W

    2017-10-01

    Microbial aerobic methane oxidation in unsaturated landfill cover involves coupled water, gas and heat reactive transfer. The coupled process is complex and its influence on methane oxidation efficiency is not clear, especially in steep covers where spatial variations of water, gas and heat are significant. In this study, two-dimensional finite element numerical simulations were carried out to evaluate the performance of unsaturated sloping cover. The numerical model was calibrated using a set of flume model test data, and was then subsequently used for parametric study. A new method that considers transient changes of methane concentration during the estimation of the methane oxidation efficiency was proposed and compared against existing methods. It was found that a steeper cover had a lower oxidation efficiency due to enhanced downslope water flow, during which desaturation of soil promoted gas transport and hence landfill gas emission. This effect was magnified as the cover angle and landfill gas generation rate at the bottom of the cover increased. Assuming the steady-state methane concentration in a cover would result in a non-conservative overestimation of oxidation efficiency, especially when a steep cover was subjected to rainfall infiltration. By considering the transient methane concentration, the newly-modified method can give a more accurate oxidation efficiency. Copyright © 2017. Published by Elsevier Ltd.

  15. Multiobjective optimization of water distribution systems accounting for economic cost, hydraulic reliability, and greenhouse gas emissions

    Science.gov (United States)

    Wu, Wenyan; Maier, Holger R.; Simpson, Angus R.

    2013-03-01

    In this paper, three objectives are considered for the optimization of water distribution systems (WDSs): the traditional objectives of minimizing economic cost and maximizing hydraulic reliability and the recently proposed objective of minimizing greenhouse gas (GHG) emissions. It is particularly important to include the GHG minimization objective for WDSs involving pumping into storages or water transmission systems (WTSs), as these systems are the main contributors of GHG emissions in the water industry. In order to better understand the nature of tradeoffs among these three objectives, the shape of the solution space and the location of the Pareto-optimal front in the solution space are investigated for WTSs and WDSs that include pumping into storages, and the implications of the interaction between the three objectives are explored from a practical design perspective. Through three case studies, it is found that the solution space is a U-shaped curve rather than a surface, as the tradeoffs among the three objectives are dominated by the hydraulic reliability objective. The Pareto-optimal front of real-world systems is often located at the "elbow" section and lower "arm" of the solution space (i.e., the U-shaped curve), indicating that it is more economic to increase the hydraulic reliability of these systems by increasing pipe capacity (i.e., pipe diameter) compared to increasing pumping power. Solutions having the same GHG emission level but different cost-reliability tradeoffs often exist. Therefore, the final decision needs to be made in conjunction with expert knowledge and the specific budget and reliability requirements of the system.

  16. Geologic, geochemical, and geographic controls on NORM in produced water from Texas oil, gas, and geothermal reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, R.

    1995-08-01

    Water from Texas oil, gas, and geothermal wells contains natural radioactivity that ranges from several hundred to several thousand Picocuries per liter (pCi/L). This natural radioactivity in produced fluids and the scale that forms in producing and processing equipment can lead to increased concerns for worker safety and additional costs for handling and disposing of water and scale. Naturally occurring radioactive materials (NORM) in oil and gas operations are mainly caused by concentrations of radium-226 ({sup 226}Ra) and radium-228 ({sup 228}Ra), daughter products of uranium-238 ({sup 238}U) and thorium-232 ({sup 232}Th), respectively, in barite scale. We examined (1) the geographic distribution of high NORM levels in oil-producing and gas-processing equipment, (2) geologic controls on uranium (U), thorium (Th), and radium (Ra) in sedimentary basins and reservoirs, (3) mineralogy of NORM scale, (4) chemical variability and potential to form barite scale in Texas formation waters, (5) Ra activity in Texas formation waters, and (6) geochemical controls on Ra isotopes in formation water and barite scale to explore natural controls on radioactivity. Our approach combined extensive compilations of published data, collection and analyses of new water samples and scale material, and geochemical modeling of scale Precipitation and Ra incorporation in barite.

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

    Science.gov (United States)

    Donaldson, D J; Valsaraj, Kalliat T

    2010-02-01

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

  18. Preliminary technical data report: WyCoalGas project water system. Final technical report, November 1980-May 1982. [Proposed WyCoalGas project, Converse County, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-01-01

    The WyCoalGas, Inc. Proposed coal gasification plant site is approximately 16 miles north of Douglas, Wyoming, located generally in Sections 27 and 34, T35N, R70W of the sixth prinicpal meridian. The plant site is located in typical high plateau plains of central Wyoming. Climate in the area is typical of semi-arid central Wyoming and is subject to wide variations in temperature. Precipitation in the area averages about 14 inches per year, of which about 10 inches fall during the April-September irrigation season. Projected water requirements at the plant site are 6020 acre-feet per year. Since the proposed plant site is not near any major streams or rivers, water must be transported to it. Water will be supplied from four sources - two surface water and two groundwater. The two surface water sources are LaPrele Reservoir and flood flows from the North Platte River with a 1974 appropriations date. LaPrele Reservoir is located approximately 14 miles west of Douglas, Wyoming, and is shown on Figure A-1. Water will be released from LaPrele Reservoir and flow down LaPrele Creek to the North Platte River. Water from the North Platte River will be diverted at a point in Section 7 of T33N, R71W. The LaPrele water and excess water from the North Platte will be pumped from the river and stored in Panhandle Reservoir No. 1, which is also referred to as Combs Reservoir. A pipeline will convey water from Panhandle Reservoir No. 1 to the coal gasification plant site. The two groundwater sources are located north of Douglas and west of Douglas.

  19. Parametric Limits of Efficient Use of a Centrifugal Water Atomizer in Contact Waste-Gas Heat-Utilization Units

    Science.gov (United States)

    Bezrodnyi, M. K.; Rachinskii, A. Yu.; Barabash, P. A.; Goliyad, N. N.

    2016-07-01

    The relation for the limiting temperature of water heating in a contact gas-droplet-type apparatus with a centrifugal atomizer has been determined experimentally in relation to the conditions of utilization of heat of power plant waste-gases. Investigations were carried out in the range of excess water pressures in front of the atomizer 0.2-0.6 MPa and of the volume fraction of steam in the vapor-gas mixture at the inlet of the apparatus from 0.02 to 0.45. The possibility of using the obtained dependence for calculating the limiting values of the vapor-gas flow parameters that limit the range of efficient operation of the contact apparatus with steam condensation and in the absence of heated liquid droplet evaporation is shown.

  20. 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

  1. Science-based decision-making on complex issues: Marcellus shale gas hydrofracking and New York City water supply.

    Science.gov (United States)

    Eaton, Timothy T

    2013-09-01

    Complex scientific and non-scientific considerations are central to the pending decisions about "hydrofracking" or high volume hydraulic fracturing (HVHF) to exploit unconventional natural gas resources worldwide. While incipient plans are being made internationally for major shale reservoirs, production and technology are most advanced in the United States, particularly in Texas and Pennsylvania, with a pending decision in New York State whether to proceed. In contrast to the narrow scientific and technical debate to date, focused on either greenhouse gas emissions or water resources, toxicology and land use in the watersheds that supply drinking water to New York City (NYC), I review the scientific and technical aspects in combination with global climate change and other critical issues in energy tradeoffs, economics and political regulation to evaluate the major liabilities and benefits. Although potential benefits of Marcellus natural gas exploitation are large for transition to a clean energy economy, at present the regulatory framework in New York State is inadequate to prevent potentially irreversible threats to the local environment and New York City water supply. Major investments in state and federal regulatory enforcement will be required to avoid these environmental consequences, and a ban on drilling within the NYC water supply watersheds is appropriate, even if more highly regulated Marcellus gas production is eventually permitted elsewhere in New York State. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. One-dimensional phenomenological model for liquid water flooding in cathode gas channel of a polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Hassanizadeh, S.M.; Rensink, D.; Fell, S.

    2012-01-01

    The mathematical description of liquid water flooding in the gas channel (GC) of a polymer electrolyte fuel cell (PEFC) at the macro scale has remained a challenge up to now. The mist flow assumption in the GC has been commonly used in previous numerical studies. In this work, a one-dimensional (dow

  3. 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

  4. Determining water influx and geological reserves for oil and gas pools from data of the history of development

    Energy Technology Data Exchange (ETDEWEB)

    Zoltan, I.; Papp, I.; Szantho, I.

    1984-01-01

    Two methods are presented for computing to determine parameters describing water influx. The question is examined of determining the geological reserves of hydrocarbons. The calculation is made on specific numerical examples for one hypothetical gas pool and pool No. 1 of the Paleozoic-Miocene of the Tazlar field.

  5. 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

  6. Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (ERD)

    Science.gov (United States)

    In this report, EPA reviews and synthesizes scientific literature to assess the potential for hydraulic fracturing for oil and gas to change the quality or quantity of drinking water resources. This report also identifies factors affecting the frequency or severity of any potenti...

  7. Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (External Review Draft)

    Science.gov (United States)

    This assessment provides a review and synthesis of available scientific literature and data to assess the potential for hydraulic fracturing for oil and gas to impact the quality or quantity of drinking water resources, and identifies factors affecting the frequency or severity o...

  8. Plant-wide Control for Better De-oiling of Produced Water in Offshore Oil & Gas Production

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Stigkær, Jens Peter; Løhndorf, Bo

    2013-01-01

    This paper discusses the application of plant-wide control philosophy to enhance the performance and capacity of the Produced Water Treatment (PWT) in offshore oil & gas production processes. Different from most existing facility- or material-based PWT innovation methods, the objective of this work...

  9. Integrated Water Gas Shift Membrane Reactors Utilizing Novel, Non Precious Metal Mixed Matrix Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, John

    2013-09-30

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed- matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H{sub 2}/CO{sub 2} selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO{sub 2}-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethanol diamine resulted in an increase in H{sub 2}/CO{sub 2} selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H{sub 2}/CO{sub 2} selectivity similar to the uncross-linked polymer. Performance of the polybenzimidazole (PBI) hollow fibers prepared at Santa Fe Science and Technology (SFST, Inc.) showed increased flux o to a flat PBI membrane. A water-gas shift reactor has been built and currently being optimized for testing under DOE conditions.

  10. CHARACTERIZING NATURAL GAS HYDRATES IN THE DEEP WATER GULF OF MEXICO: APPLICATIONS FOR SAFE EXPLORATION AND PRODUCTION ACTIVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Steve Holditch; Emrys Jones

    2003-01-01

    In 2000, Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deepwater portions of the Gulf of Mexico. A Joint Industry Participation (JIP) group was formed in 2001, and a project partially funded by the U.S. Department of Energy (DOE) began in October 2001. The primary objective of this project is to develop technology and data to assist in the characterization of naturally occurring gas hydrates in the deep water Gulf of Mexico (GOM). These naturally occurring gas hydrates can cause problems relating to drilling and production of oil and gas, as well as building and operating pipelines. Other objectives of this project are to better understand how natural gas hydrates can affect seafloor stability, to gather data that can be used to study climate change, and to determine how the results of this project can be used to assess if and how gas hydrates act as a trapping mechanism for shallow oil or gas reservoirs. During the first six months of operation, the primary activities of the JIP were to conduct and plan Workshops, which were as follows: (1) Data Collection Workshop--March 2002 (2) Drilling, Coring and Core Analyses Workshop--May 2002 (3) Modeling, Measurement and Sensors Workshop--May 2002.

  11. CHARACTERIZING NATURAL GAS HYDRATES IN THE DEEP WATER GULF OF MEXICO: APPLICATIONS FOR SAFE EXPLORATION AND PRODUCTION ACTIVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Steve Holditch; Emrys Jones

    2003-01-01

    In 2000, Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deepwater portions of the Gulf of Mexico. A Joint Industry Participation (JIP) group was formed in 2001, and a project partially funded by the U.S. Department of Energy (DOE) began in October 2001. The primary objective of this project is to develop technology and data to assist in the characterization of naturally occurring gas hydrates in the deep water Gulf of Mexico (GOM). These naturally occurring gas hydrates can cause problems relating to drilling and production of oil and gas, as well as building and operating pipelines. Other objectives of this project are to better understand how natural gas hydrates can affect seafloor stability, to gather data that can be used to study climate change, and to determine how the results of this project can be used to assess if and how gas hydrates act as a trapping mechanism for shallow oil or gas reservoirs. During April-September 2002, the JIP concentrated on: Reviewing the tasks and subtasks on the basis of the information generated during the three workshops held in March and May 2002; Writing Requests for Proposals (RFPs) and Cost, Time and Resource (CTRs) estimates to accomplish the tasks and subtasks; Reviewing proposals sent in by prospective contractors; Selecting four contractors; Selecting six sites for detailed review; and Talking to drill ship owners and operators about potential work with the JIP.

  12. Chemical and isotopic characteristics of gas hydrate- and pore-water samples obtained from gas hydrate-bearing sediment cores retrieved from a mud volcano in the Kukuy Canyon, Lake Baikal

    Energy Technology Data Exchange (ETDEWEB)

    Minami, H.; Hachikubo, A.; Krylov, A.; Sakagami, H.; Ohashi, M.; Bai, J.; Kataoka, S.; Yamashita, S.; Takahashi, N.; Shoji, H. [Kitami Inst. of Technology, Kitami (Japan); Khlystov, O.; Zemskaya, T.; Grachev, M. [Russian Academy of Sciences, Irkutsk (Russian Federation). Limnological Inst.

    2008-07-01

    This paper provided details of a method developed to obtain gas hydrate water samples from a mud volcano in Lake Baikal, Russia. Chemical and isotopic analyses were conducted to examine the hydrate and pore water samples as well as to evaluate the original water involved in shallow gas hydrate accumulations in the region. Lake sediment core samples were retrieved from the bottom of the lake with gravity corers. A squeezer was used to take pore water samples from the sediments. Hydrate samples were taken from a gas hydrate placed on a polyethylene funnel. Dissolved hydrate water was filtered through a membrane into bottles. Both samples were kept under chilled or liquid nitrogen temperatures. Ion chromatography was used to determine concentrations of anions and hydrogen carbonate ions. Sodium and magnesium concentrations were determined using an inductively coupled plasma atomic emission spectrometer. An absorption spectrometer was used to determine potassium and calcium concentrations, and a mass spectrometer was used to analyze stable isotopes of oxygen and hydrogen. Results of the study suggested that the gas dissolved in pore water and adsorbed on the surfaces of sediment particles was not the original gas from the hydrates retrieved at the mud volcano. Original gas hydrate-forming fluids were chemically different from the pore- and lake-water samples. The oxygen isotopic composition of the gas hydrate water samples correlated well with hydrogen values. It was concluded that ascending fluid and water delivered the gas into the gas stability zone, and is the main gas hydrate-forming fluid in the area of study. 12 refs., 1 fig.

  13. Direct measurements of wind-water momentum coupling in a marsh with emergent vegetation and implications for gas transfer estimates

    Science.gov (United States)

    Tse, I.; Poindexter, C.; Variano, E. A.

    2013-12-01

    Among the numerous ecological benefits of restoring wetlands is carbon sequestration. As emergent vegetation thrive, atmospheric CO2 is removed and converted into biomass that gradually become additional soil. Forecasts and management for these systems rely on accurate knowledge of gas exchange between the atmosphere and the wetland surface waters. Our previous work showed that the rate of gas transfer across the air-water interface is affected by the amount of water column mixing caused by winds penetrating through the plant canopy. Here, we present the first direct measurements of wind-water momentum coupling made within a tule marsh. This work in Twitchell Island in the California Delta shows how momentum is imparted into the water from wind stress and that this wind stress interacts with the surface waters in an interesting way. By correlating three-component velocity signals from a sonic anemometer placed within the plant canopy with data from a novel Volumetric Particle Imager (VoPI) placed in the water, we measure the flux of kinetic energy through the plant canopy and the time-scale of the response. We also use this unique dataset to estimate the air-water drag coefficient using an adjoint method.

  14. Modeling impacts of changes in temperature and water table on C gas fluxes in an Alaskan peatland

    Science.gov (United States)

    Deng, Jia; Li, Changsheng; Frolking, Steve

    2015-07-01

    Northern peatlands have accumulated a large amount of organic carbon (C) in their thick peat profile. Climate change and associated variations in soil environments are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is still highly uncertain. Verifying and understanding the influences of changes in environmental factors on C gas fluxes in biogeochemical models are essential for forecasting feedbacks between C gas fluxes and climate change. In this study, we applied a biogeochemical model, DeNitrification-DeComposition (DNDC), to assess impacts of air temperature (TA) and water table (WT) on C gas fluxes in an Alaskan peatland. DNDC was validated against field measurements of net ecosystem exchange of CO2 (NEE) and CH4 fluxes under manipulated surface soil temperature and WT conditions in a moderate rich fen. The validation demonstrates that DNDC was able to capture the observed impacts of the manipulations in soil environments on C gas fluxes. To investigate responses of C gas fluxes to changes in TA and soil water condition, we conducted a series of simulations with varying TA and WT. The results demonstrate that (1) uptake rates of CO2 at the site were reduced by either too colder or warmer temperatures and generally increased with increasing soil moisture; (2) CH4 emissions showed an increasing trend as TA increased or WT rose toward the peat surface; and (3) the site could shift from a net greenhouse gas (GHG) sink into a net GHG source under some warm and/or dry conditions. A sensitivity analysis evaluated the relative importance of TA and WT to C gas fluxes. The results indicate that both TA and WT played important roles in regulating NEE and CH4 emissions and that within the investigated ranges of the variations in TA and WT, changes in WT showed a greater impact than changes in TA on NEE, CH4 fluxes, and net C gas fluxes at the study fen.

  15. Comparison of gas chromatography-mass spectrometry and gas chromatography-tandem mass spectrometry with electron ionization for determination of N-nitrosamines in environmental water.

    Science.gov (United States)

    Chen, Wenwen; Li, Xiaoshui; Huang, Huanfang; Zhu, Xuetao; Jiang, Xiaoyu; Zhang, Yuan; Cen, Kuang; Zhao, Lunshan; Liu, Xiuli; Qi, Shihua

    2017-02-01

    N-nitrosamines are trace organic contaminants of environmental concern when present in groundwater and river water due to their potent carcinogenicity. Therefore, N-nitrosamine analysis is increasingly in demand. Gas chromatography-mass spectrometry (GC-MS) and GC-tandem mass spectrometry (GC-MS/MS), both with electron ionization (EI), were compared for analysis of nine N-nitrosamines extracted from environmental water matrices. A total of 20 fishpond water, river water, and groundwater samples from Sihui and Shunde, China were collected for a survey of N-nitrosamine concentrations in real water samples. Various solid-phase extraction (SPE) conditions and GC conditions were first examined for the pre-concentration and separation steps. The analysis of N-nitrosamines in environmental waters demonstrated that their quantification with GC-MS poses a challenge due to the occurrence of co-eluting interferences. Conversely, the use of GC-MS/MS increased selectivity because of the fragmentation generated from precursor ions in the 'multiple reaction monitoring' (MRM) mode, which is expected to extract target analytes from the environmental water matrix. Thus, the high performance of GC-MS/MS with EI was used to quantify nine N-nitrosamines in environmental waters with detection limits of 1.1-3.1 ng L(-1). N-nitrosodimethylamine (NDMA) concentrations were in the range of N.D. to 258 ng L(-1). Furthermore, other N-nitrosamines, except N-nitrosomethylethylamine (NMEA), N-nitroso-di-n-propylamine (NDPA) and N-nitrosopiperidine (NPIP), were also detected. Our findings suggest that GC-MS/MS with EI would be widely applicable in identifying N-nitrosamines in environmental waters and can be used for routine monitoring of these chemicals.

  16. Fluid geochemistry of the Mondragone hydrothermal systems (southern Italy): water and gas compositions vs. geostructural setting

    Science.gov (United States)

    Cuoco, Emilio; Minissale, Angelo; Di Leo, Antonella "Magda"; Tamburrino, Stella; Iorio, Marina; Tedesco, Dario

    2017-02-01

    The geochemistry of natural thermal fluids discharging in the Mondragone Plain has been investigated. Thermal spring emergences are located along the Tyrrhenian coast in two different areas: near Padule-S. Rocco (41°7.5'N 13°53.4'E) at the foot of Mt. Petrino, and near Levagnole (41°8.5'N 13°51.3'E) at the foot of Mt. Pizzuto. The water isotopic composition of both thermal discharges is lighter than the one of local shallow groundwater (δ18O ≅ -6.3‰ SMOW vs. ≅ -5.9‰; δD ≅ -40‰ SMOW vs. ≅ -36‰, respectively) as a consequence of inland higher altitude of recharge by rainfall, suggesting that thermal water undergoes a deep and long flow-path before emerging along the coast. The chemical composition of the highest temperature samples of two areas points that fluids in the hydrothermal reservoir(s) interact with similar lithologies, since they are both hosted in the lower sedimentary carbonate formations of the Campanian-Latial Apennine succession. However, the two spring systems are different in terms of temperature and salinity (Levagnole: ≅50 °C and 8.9 g/L vs. Padule: ≅32 °C and 7.4 g/L, respectively). The higher salinity of Levagnole springs is due to a longer interaction with evaporite material embedded in Miocene sedimentary formations and to the eventual mixing, during rising, with fresh seawater close to the seashore. The chemical and isotopic composition of the free gases associated with the springs, again suggests a different source of the two hydrothermal systems. Comparing the 3He/4He measured ratios with other gas emissions located NE and SE of Mt. Massico-Roccamonfina alignment, it is evident that the Levagnole thermal springs are related to the northern Latial mantle wedge where the 3He/4He is about 0.5 R/Ra, whereas the Padule-S. Rocco springs, although being only 3.5 km south of Levagnole, are related to the Campanian mantle wedge where R/Ra is always ≥2.0. Such a difference in 3He/4He ratio in a very short distance

  17. Science-based decision-making on complex issues: Marcellus shale gas hydrofracking and New York City water supply

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, Timothy T., E-mail: Timothy.Eaton@qc.cuny.edu

    2013-09-01

    Complex scientific and non-scientific considerations are central to the pending decisions about “hydrofracking” or high volume hydraulic fracturing (HVHF) to exploit unconventional natural gas resources worldwide. While incipient plans are being made internationally for major shale reservoirs, production and technology are most advanced in the United States, particularly in Texas and Pennsylvania, with a pending decision in New York State whether to proceed. In contrast to the narrow scientific and technical debate to date, focused on either greenhouse gas emissions or water resources, toxicology and land use in the watersheds that supply drinking water to New York City (NYC), I review the scientific and technical aspects in combination with global climate change and other critical issues in energy tradeoffs, economics and political regulation to evaluate the major liabilities and benefits. Although potential benefits of Marcellus natural gas exploitation are large for transition to a clean energy economy, at present the regulatory framework in New York State is inadequate to prevent potentially irreversible threats to the local environment and New York City water supply. Major investments in state and federal regulatory enforcement will be required to avoid these environmental consequences, and a ban on drilling within the NYC water supply watersheds is appropriate, even if more highly regulated Marcellus gas production is eventually permitted elsewhere in New York State. - Highlights: • Analyses of hydrofracking for natural gas production worldwide are too focused. • Energy benefits are great but so are environmental/public health liabilities. • Current dependence on even more damaging coal-fired power can be reduced. • Protecting watersheds for NYC and other municipality water supply is paramount. • Strengthening of regulation is needed for reducing potential adverse impacts.

  18. 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 dept