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Stresses and fractures in the Frontier Formation, Green River Basin, predicted from basin-margin tectonic element interactions

Description: Natural fractures and in situ stresses commonly dictate subsurface reservoir permeability and permeability anisotropy, as well as the effectiveness of stimulation techniques in low-permeability, natural gas reservoirs. This paper offers an initial prediction for the orientations of the fracture and stress systems in the tight gas reservoirs of the Frontier Formation, in the Green River basin of southwestern Wyoming. It builds on a previous report that addressed fractures and stresses in the western part of the basin and on ideas developed for the rest of the basin, using the principle that thrust faults are capable of affecting the stress magnitudes and orientations in little-deformed strata several hundreds of kilometers in front of a thrust. The prediction of subsurface stresses and natural fracture orientations is an undertaking that requires the willingness to revise models as definitive data are acquired during drilling. The predictions made in this paper are offered with the caveat that geology in the subsurface is always full of surprises.
Date: January 1, 1996
Creator: Lorenz, J.C.
Partner: UNT Libraries Government Documents Department

Development of polymer concrete for dike insulation at LNG facilities: Phase 4, Low cost materials. Final report, September 1, 1987--April 30, 1990

Description: Earlier GRI-sponsored work at Brookhaven National Laboratory has resulted in the development and utilization of insulating polymer concrete composites (IPC) as a means of reducing the evaporation rate of liquified natural gas in the event of a spill into a containment dike, thereby improving the safety at these sites. Although all of the required properties can be attained with the IPC, it was estimated that a low-cost replacement for the expensive organic binder would be necessary before use of the material would be cost-effective. In the current program, several latex modified cement formulations were evaluated and the most promising one identified. A mixture of two carboxylated styrene-butadiene latexes was selected for use in detailed laboratory property characterizations and a subsequent field evaluation. When compared to the properties of IPC, the latex-modified insulating materials display somewhat higher thermal conductivities, greater permeability to water, and reduced strength. However, these properties still meet most of the performance criteria, and the unit cost of the material is less than one-fifth that of IPC made with epoxy binders. When installed as a 0.75-in. thick overlay, material costs are estimated to be $1.00/ft{sup 2}.
Date: January 1, 1991
Creator: Kukacka, L. E.
Partner: UNT Libraries Government Documents Department

Monte Carlo investigation of through-casing {gamma}-{gamma} density logging

Description: This report documents research I performed, employing Monte Carlo parametric simulations. I investigated the concept of utilizing high-energy {gamma} rays for through-casing density logging. The research exploits the findings of my previously proof-of-concept, the present goal having been to characterize a generic {gamma}-{gamma} tool in various scenarios. In the process, I generated a database of tool-design information. My analysis of the computed results identified a novel design-evaluation technique, a natural extension of my earlier concept to use the formation signal as a quality gauge for the detected signal: Analysis of the formation signal determines, a priori, whether a specific combination of design parameters is, intrinsically, compatible or mismatched. It must be noted that the new technique is only possible in simulations of the present kind. But it is not limited to the set of parameters investigated in the present studies. Hence, any effort to design a prototype tool can benefit significantly from its application. The technique amplifies the power of simulation, which is an inherently cost effective adjunct to ``cutting metal.``
Date: September 1, 1994
Creator: Lichtenstein, H.
Partner: UNT Libraries Government Documents Department

Evaluation of high-efficiency gas liquid contactors for natural gas processing

Description: The objectives of this program are to develop and evaluate advanced processing technologies that can reduce the cost of upgrading sub quality natural gas to pipeline standards. The successful application of cost-effective, new technologies will facilitate the production of sub quality natural gas that otherwise would be too expensive to produce. The overall program is focused on the following activities: evaluation of the potential of structured packing for the removal of acid gases from natural gases, and expansion of the currently available database of the fluid dynamics of rotating gas liquid contactors. The natural gas sweetening, structured packing field tests are scheduled to be conducted in calendar year 1995. Design, procurement and construction of the field test unit. Expansion of the available data base on the hydraulic characteristics of a rotating gas-liquid contactor is being pursued through a series of laboratory experiments. A 100 GPM, low pressure rotary contactor system has been assembled at IGT`s Energy Development Center to examine the fluid dynamic behavior of this type of contactor. The studies are determining the effects of liquid viscosity, liquid surface tension and operating conditions on liquid residence times and flooding limits.
Date: June 1, 1995
Creator: Palla, N. & Lee, A.L.
Partner: UNT Libraries Government Documents Department

Tubular solid oxide fuel cell developments

Description: An overview of the tubular solid oxide fuel cell (SOFC) development at Westinghouse is presented in this paper. The basic operating principles of SOFCs, evolution in tubular cell design and performance improvement, selection criteria for cell component materials, and cell processing techniques are discussed. The commercial goal is to develop a cell that can operate for 5 to 10 years. Results of cell test operated for more than 50,000 hours are presented. Since 1986, significant progress has been made in the evolution of cells with higher power, lower cost and improved thermal cyclic capability. Also in this period, successively larger multi-kilowatt electrical generators systems have been built and successfully operated for more than 7000 hours.
Date: August 1, 1995
Creator: Bratton, R.J. & Singh, P.
Partner: UNT Libraries Government Documents Department

Microbially-enhanced redox solution reoxidation for sweetening sour natural gas

Description: About twenty five percent of natural gas produced in the United States is sour containing significant volumes of hydrogen sulfide and other contaminants. Liquid redox processes remove hydrogen sulfide from natural gas. Aqueous solution of chelated ferric ions oxidize the hydrogen sulfide to elemental sulfur. The reduced iron chelate is then oxidized by contact with air and recycled. This requires expensive equipment for regeneration, costly chemicals and the process is usually energy intensive. Recent studies show that the ferric ion regeneration rates are substantially enhanced in presence of acidophilic bacteria. The specific objectives of this project are to advance the technology and improve the economics of the commercial iron-based chelate processes utilizing biologically-enhanced reoxidation of the redox solutions used in these processes, such as LO-CAT II and SulFerox.
Date: June 1995
Creator: Rai, C.
Partner: UNT Libraries Government Documents Department

Development of polymer concrete for dike insulation at LNG facilities: Phase 4, Low cost materials

Description: Earlier GRI-sponsored work at Brookhaven National Laboratory has resulted in the development and utilization of insulating polymer concrete composites (IPC) as a means of reducing the evaporation rate of liquified natural gas in the event of a spill into a containment dike, thereby improving the safety at these sites. Although all of the required properties can be attained with the IPC, it was estimated that a low-cost replacement for the expensive organic binder would be necessary before use of the material would be cost-effective. In the current program, several latex modified cement formulations were evaluated and the most promising one identified. A mixture of two carboxylated styrene-butadiene latexes was selected for use in detailed laboratory property characterizations and a subsequent field evaluation. When compared to the properties of IPC, the latex-modified insulating materials display somewhat higher thermal conductivities, greater permeability to water, and reduced strength. However, these properties still meet most of the performance criteria, and the unit cost of the material is less than one-fifth that of IPC made with epoxy binders. When installed as a 0.75-in. thick overlay, material costs are estimated to be $1.00/ft{sup 2}.
Date: January 1, 1991
Creator: Kukacka, L.E.
Partner: UNT Libraries Government Documents Department

Sampling and analyses report for December 1992 semiannual postburn sampling at the RMI UCG Site, Hanna, Wyoming

Description: During December 1992, groundwater was sampled at the site of the November 1987--February 1988 Rocky Mountain 1 underground coal gasification test near Hanna, Wyoming. The groundwater in near baseline condition. Data from the field measurements and analyzes of samples are presented. Benzene concentrations in the groundwater are below analytical detection limits (<0.01 mg/L) for all wells, except concentrations of 0.016 mg/L and 0.013 mg/L in coal seam wells EMW-3 and EMW-1, respectively.
Date: March 1, 1993
Creator: Lindblom, S. R.
Partner: UNT Libraries Government Documents Department

Sampling and analyses report for the September 1989 postburn sampling at the RM1 UCG Site, Hanna, Wyoming

Description: Between September 14, 1989 and September 19, 1989, Western Research Institute (WRI) completed the third quarterly Rocky Mountain 1 (RM1) groundwater monitoring for the year 1989. This quarterly sample outing represents the first sampling since the completion of the second RM1 groundwater restoration in August 1989. Background material and the sampling and analytical procedures associated with this task are described in the Rocky Mountain 1 Postburn Groundwater Monitoring Quality Assurance Plan, prepared by Western Research Institute for the Gas Research Institute and the US Department of Energy.
Date: September 1, 1989
Creator: Crader, S. E.
Partner: UNT Libraries Government Documents Department

Analysis of the impacts of energy conservation codes in new single-family homes

Description: Within the 50 states some form of federal code or standard for energy conservation in new building construction is typically incorporated into state and local codes. Two of these codes, the Model Energy Code (MEC) and the proposed ASHRAE standard 90.2P are of special importance to the residential data base developed by the Gas Research Institute (GRI) because they influence thermal requirements and have either been recently updated or will be revised in 1992. In this study, we evaluate the impacts of these two thermal codes on the energy performance and energy consumption of prototypical new single-family buildings. Base case buildings, with characteristics typical of current building practices, are modified to meet the thermal envelope standards and are simulated with the DOE-2.1D building energy simulation program. In addition, we also model the effects of appliance and heating and cooling equipment efficiencies promulgated under the National Appliance Energy Conservation Act (NAECA) of 1987 and of the NAECA Amendments of 1988. We compare heating and cooling loads and energy use for the prototypical house for several cases: the base case, with 1980s vintage thermal envelope and appliance and equipment efficiencies; with ASHRAE 90 thermal requirements; with Model Energy Code thermal requirements; with NAECA appliance and HVAC efficiencies; and with combinations of the ASHRAE 90 Standard or Model Energy Code and the NAECA appliance and equipment efficiency improvements. The results provide a glimpse of how these standards will affect future end-use energy consumption in new single-family buildings.
Date: December 1, 1992
Creator: Ritschard, R. L.; Hanford, J. W. & Sezgen, A. O.
Partner: UNT Libraries Government Documents Department

Insights gained from studies of gas pipeline rights-of-way of varying ages through wetlands

Description: Impacts of gas pipeline rights-of-way (ROWs) through wetlands depend on types of habitat, construction techniques, final elevations, ROW maintenance practices, soil composition, and local climate. In some instances factors unrelated to the presence of the pipeline may have greater impacts on wetland modification than does the pipeline itself. At one site, the required seeding program inhibited natural reestablishment of wetland plants; at another, downstream construction resulted in a major disruption to the adjacent wetland habitat. This paper discusses observation from 13 study sites, each zero to 30 years old, that are located in seven Eastern States.
Date: October 1, 1993
Creator: Zimmerman, R. E.; Shem, L. & Van Dyke, G. D.
Partner: UNT Libraries Government Documents Department

Use of geographic information systems for applications on gas pipeline rights-of-way

Description: Geographic information system (GIS) applications for the siting and monitoring of gas pipeline rights-of-way (ROWS) were developed for areas near Rio Vista, California. The data layers developed for this project represent geographic features, such as landcover, elevation, aspect, slope, soils, hydrography, transportation, endangered species, wetlands, and public line surveys. A GIS was used to develop and store spatial data from several sources; to manipulate spatial data to evaluate environmental and engineering issues associated with the siting, permitting, construction, maintenance, and monitoring of gas pipeline ROWS; and to graphically display analysis results. Examples of these applications include (1) determination of environmentally sensitive areas, such as endangered species habitat, wetlands, and areas of highly erosive soils; (2) evaluation of engineering constraints, including shallow depth to bedrock, major hydrographic features, and shallow water table; (3) classification of satellite imagery for land use/landcover that will affect ROWS; and (4) identification of alternative ROW corridors that avoid environmentally sensitive areas or areas with severe engineering constraints.
Date: October 1, 1993
Creator: Sydelko, P. J.
Partner: UNT Libraries Government Documents Department

Plasma-chemical treatment of hydrogen sulfide in natural gas processing. Final report, May 1991--December 1992

Description: A new process for the treatment of hydrogen sulfide waste that uses microwave plasma-chemical technology has been under development in Russia and the United States. Whereas the present waste-treatment technology, at best, only recovers sulfur, this novel process recovers both hydrogen and sulfur by dissociating hydrogen sulfide in a plasma by means of a microwave or radio-frequency reactor. A research project has been undertaken to determine the suitability of the plasma process in natural gas processing applications. The experiments tested acid-gas compositions with 30--65% carbon dioxide, 0--7% water, and 0--0.2% of a standard mixture of pipeline gas. The balance gas in all cases was hydrogen sulfide. The reactor pressure for the experiments was 50 torr, and the microwave power was 1.0 kW. Conversions of hydrogen sulfide ranged from 80 to 100%, while 35--50% of the carbon dioxide was converted to carbon monoxide. This conversion of carbon dioxide resulted in a loss of hydrogen production and an energy loss from a hydrogen sulfide waste-treatment perspective. Tests of a direct natural gas treatment concept showed that hydrocarbon losses were unacceptably high; consequently, the concept would not be economically viable.
Date: May 1, 1993
Creator: Harkness, J. B. L. & Doctor, R. D.
Partner: UNT Libraries Government Documents Department

Pipeline corridors through wetlands

Description: This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.
Date: December 1, 1992
Creator: Zimmerman, R. E.; Wilkey, P. L. & Isaacson, H. R.
Partner: UNT Libraries Government Documents Department

Methyl chloride via oxyhydrochlorination of methane. Quarterly technical progress report No. 6, January--March 1993

Description: The purpose of this contract is to develop a process for converting light alkane gases to methyl chloride via oxyhydrochlorination using highly selective, stable catalysts in fixed-bed reactors designed to remove the large amount of heat generated, so as to control the reaction temperature. Further, the objective is to obtain the engineering data base necessary for developing a commercially feasible process and to evaluate the economics of the process. This document reports significant progress this quarter toward the development of a stable heterogeneous packed bed catalyst for the oxyhydrochlorination of methane. This quarter`s data shows a catalyst which gave an average 18% methane conversion and 78% MeCl selectivity for a 12 day period of time. The PDU (Process Development Unit) design engineering effort made significant progress this quarter. A bid on a modular unit by Xytel Corp. was received and evaluated. The pre-engineering estimate showed that costs were considerably higher than the original project capital estimates. A rigorous effort was made to eliminate all non-essential equipment and scope of work. A reduced scope was agreed upon and in the second round both Xytel and the Dow Corning in-house facilities engineering team were allowed to bid on the package.
Date: November 1, 1993
Partner: UNT Libraries Government Documents Department

Solid-state NMR characterization of Mowry Formation shales

Description: Solid-state {sup 13}C and {sup 29}Si NMR measurements were carried out on a series of petroleum source rocks from the Mowry Formation of the Powder River Basin in Wyoming. The objectives of this study wereto use CP/MAS {sup 13}C NMR measurements to monitor changes in the carbon structure of the kerogen that result from depth of burial, and to examine the feasibility of {sup 29}Si NMR for studying the thermal alteration of clay minerals during diagenesis. Carbon and silicon NMR measurements were made on a suite of samples covering a present-day depth interval of 3,000 to 11,500 ft.In general, the NMR results endorsed other geochemical analyses that were performed on the source rocks as part of another study to examine pressure compartmentalization in the Mowry Formation. The carbon aromaticity of the kerogen increased with depth of burial, and at depths greater that approximately 10,000 ft the kerogen showed little capacity to generate additional oil because of the small fraction of residual aliphatic carbon. By combining NMR and Rock-Eval measurements, an estimate of the hydrogen budget was obtained. The calculations indicated that approximately 20% of the kerogen was converted to hydrocarbons, and that sufficient hydrogen was liberated from aromatization and condensation reactions to stabilize the generated products. The {sup 29}Si NMR spectra were characterized by a relatively sharp quartz resonance and a broad resonance from the clay minerals. With increasing depth of burial, the clay resonance became broader and shifted slightly downfield. These changes qualitatively support X-ray analysis that shows progressive alteration of illite to smectite with depth of burial.
Date: April 1, 1992
Creator: Miknis, F. P.
Partner: UNT Libraries Government Documents Department

Observations of broad-band micro-seisms during reservoir stimulation

Description: During hydrocarbon reservoir stimulation such as hydraulic fracturing, the cracking and slippage of the formation results in the emission of seismic energy. The objective of this study was to determine the properties of these induced micro-seisms. A hydraulic fracture experiment was performed in the Piceance Basin of Western Colorado to induce and record micro-seismic events. The formation was subjected to four processes; breakdown/ballout, step-rate test, KCL mini-fracture, and linear-gel mini-fracture. Micro-seisms were acquired with an advanced three-component wall-locked seismic accelerometer package, placed in an observation well 211 ft offset from the well. During the two hours of formation treatment, more than 1200 micro-seisms with signal-to-noise ratios in excess of 20 dB were observed. The observed micro-seisms had a nominally flat frequency from 100 Hz to 1500 Hz and lack the spurious tool-resonance effects evident in previous attempts to measure micro-seisms. Both p-wave and s-wave arrivals are clearly evident in the data set, and hodogram analysis yielded coherent estimates of the event locations. This paper describes the characteristics of the observed micro-seismic events (event occurrence, signal-to-noise ratios, and bandwidth) and illustrates that the new acquisition approach results in enhanced detectability and event location resolution.
Date: April 1, 1993
Creator: Sleefe, G. E.; Warpinski, N. R. & Engler, B. P.
Partner: UNT Libraries Government Documents Department

Use of GRASS for routing gas pipeline rights-of-way

Description: This study, sponsored by the Gas Research Institute (GRI), was conducted to illustrate how a GIS (Geographic Information System) can be used to assess alternative routes for new gas pipeline rights-of-way (ROWs). The results show that a least-cost analysis using GRASS (Geographic Resources Analysis and Support System) is a good method for siting new gas pipeline ROWs on the basis of environmental and engineering constraints to pipeline construction and maintenance. The cost and time needed to use this least-cost approach compare favorably with the current methods used by gas pipeline company planners and engineers. The types of criteria used, as well as the costs or weights given to the criteria, can be changed easily. This provides the flexibility to assess several alternatives quickly and easily.
Date: July 1, 1992
Creator: Sydelko, P. J.
Partner: UNT Libraries Government Documents Department

Methyl chloride via oxyhydrochlorination of methane. Quarterly technical progress report No. 7, April--June 1993

Description: The purpose of this contract is to develop a process for converting light alkane gases to methyl chloride via oxyhydrochlorination using highly selective, stable catalysts in fixed-bed reactors designed to remove the large amount of heat generated, so as to control the reaction temperature. Further, the objective is to obtain the engineering data base necessary for developing a commercially feasible process and to evaluate the economics of the process. Several key technology areas were evaluated this quarter. The catalyst definition effort focused on the determination of the role of the Li and La promoters that have been found to be useful in enhancing Cu based oxyhydrochlorination of methane catalysts. Initial experiments show that the La acts to provide a much more active catalyst than the Cu only case. The role of the Li is ambiguous at this point. The Li enhances the stability of the La promoted catalyst, but gives only marginal improvement by itself This work will be continued, with additional emphasis on the analysis of the catalysts to determine the structural role that the promoters may play. The separation unit operation definition made significant progress by demonstrating in a laboratory system that a process solvent may be used to remove the product CH{sub 3}Cl from the reactor effluent stream. To date the data has been qualitative, but clear. Work will continue to gather the information possible in the laboratory to help with PDU design. An extensive amount of testing was performed on the chosen process solvent, Multitherm. A comprehensive review of all the thermal testing and associated FTIR, UV/VIS, and physical property testing is included in this report. This work shows that Multitherm should give the desired stability and solubility that are necessary to make the separation unit operation successful.
Date: January 1, 1994
Partner: UNT Libraries Government Documents Department

A comparison between direct spark ignition and prechamber ignition in an internal combustion engine

Description: We simulated the flow field and flame propagation near top dead center in a generic large-bore internal combustion engine using the COYOTE computer program, which is based on the full Navier-Stokes equations for a fluid mixture. The combustion chamber is a right circular cylinder, and the main charge is uniformly premixed. The calculations are axisymmetric. The results illustrate the differences in flow patterns, flame propagation, and thermal NO production between ignition with a spark plug and with a small prechamber. In the spark-ignited case, the flame propagates away from the spark plug approximately as a segment of a spherical surface, just as expected. With the prechamber, a high speed jet of hot combustion products shoots into the main chamber, quickly producing a large flame sheet that spreads along the piston face. The prechamber run consumes all of the fuel in half the time required by the spark-ignited case. The two cases produce comparable amounts of thermal NO at the end of fuel combustion.
Date: December 3, 1993
Creator: Cloutman, L. D.
Partner: UNT Libraries Government Documents Department

Analysis of the impacts of energy conservation codes in new single-family homes

Description: Within the 50 states some form of federal code or standard for energy conservation in new building construction is typically incorporated into state and local codes. Two of these codes, the Model Energy Code (MEC) and the proposed ASHRAE standard 90.2P are of special importance to the residential data base developed by the Gas Research Institute (GRI) because they influence thermal requirements and have either been recently updated or will be revised in 1992. In this study, we evaluate the impacts of these two thermal codes on the energy performance and energy consumption of prototypical new single-family buildings. Base case buildings, with characteristics typical of current building practices, are modified to meet the thermal envelope standards and are simulated with the DOE-2.1D building energy simulation program. In addition, we also model the effects of appliance and heating and cooling equipment efficiencies promulgated under the National Appliance Energy Conservation Act (NAECA) of 1987 and of the NAECA Amendments of 1988. We compare heating and cooling loads and energy use for the prototypical house for several cases: the base case, with 1980s vintage thermal envelope and appliance and equipment efficiencies; with ASHRAE 90 thermal requirements; with Model Energy Code thermal requirements; with NAECA appliance and HVAC efficiencies; and with combinations of the ASHRAE 90 Standard or Model Energy Code and the NAECA appliance and equipment efficiency improvements. The results provide a glimpse of how these standards will affect future end-use energy consumption in new single-family buildings.
Date: December 1, 1992
Creator: Ritschard, R.L.; Hanford, J.W. & Sezgen, A.O.
Partner: UNT Libraries Government Documents Department

Permeability reduction by pyrobitumen, mineralization, and stress along large natural fractures in sandstones at 18,300 ft. depth: Destruction of a reservoir

Description: Production of gas from the Frontier Formation at 18,300 R depth in the Frewen No. 4 Deep well, eastern Green River basin (Wyoming), was uneconomic despite the presence of numerous open natural fractures. Initial production tested at 500 MCFD, but dropped from 360 MCFD to 140 MCFD during a 10-day production test, and the well was abandoned. Examination of the fractures in the core suggests several probable reasons for this poor production. One factor is the presence of a hydrocarbon residue (carbon) which filled much of the porosity left in the smaller fractures after mineralization. An equally important factor is probably the reorientation of the in situ horizontal compressive stress to a trend normal to the main fractures, and which now acts to close fracture apertures rapidly during reservoir drawdown. This data set has unpleasant implications for the search for similar, deep fractured reservoirs.
Date: November 1, 1996
Creator: Lorenz, J.C.; Billingsley, R.L. & Evans, L.W.
Partner: UNT Libraries Government Documents Department

Enhancing the use of coals by gas reburning-sorbent injection: Volume 3 -- Gas reburning-sorbent injection at Edwards Unit 1, Central Illinois Light Company. Final report

Description: Design work has been completed for a Gas Reburning-Sorbent Injection (GR-SI) system to reduce emissions of NO{sub x} and SO{sub 2} from a wall fired unit at Central Illinois Light Company`s Edwards Station Unit 1, located in Bartonville, Illinois. The goal of the project was to reduce emissions of NO{sub x} by 60%, from the as found baseline of 0.98 lb/MBtu and to reduce emissions of SO{sub 2} by 50%. Since the unit currently fires a blend of high sulfur Illinois coal and low sulfur Kentucky coal to meet an SO{sub 2} limit of 1.8 lb/MBtu, the goal at this site was amended to meeting this limit while increasing the fraction of high sulfur coal to 57% from the current 15% level. GR-SI requires injection of natural gas into the furnace at the level of the top burner row, creating a fuel-rich zone in which NO{sub x} formed in the coal zone is reduced to N{sub 2}. Recycled flue gas is used to increase the reburning fuel jet momentum, resulting in enhanced mixing. Recycled flue gas is also used to cool the top row of burners which would not be in service during GR operation. Dry hydrated lime sorbent is injected into the upper furnace to react with SO{sub 2}, forming solid CaSO{sub 4} and CaSO{sub 3}, which are collected by the ESP. The system was designed to inject sorbent at a rate corresponding to a calcium (sorbent) to sulfur (coal) molar ratio of 2.0. The SI system design was optimized with respect to gas temperature, injection air flow rate, and sorbent dispersion. Sorbent injection air flow is equal to 3% of the combustion air. The design includes modifications of the ESP, sootblowing, and ash handling systems.
Date: March 1, 1996
Partner: UNT Libraries Government Documents Department

Biotreatment of produced waters for volume reduction and contaminant removal

Description: Produced water is wastewater that is brought to the surface from natural gas wells during natural gas production. Its constituents, mostly salt, with traces of hydrocarbons and heavy metals, are a significant disposal problem. Argonne National Laboratory (ANL), in partnership with the Gas Research Institute (GRI), has developed a low-cost, low-tech method, in which green plants are used to reduce the volume of produced water. The authors have designed an engineered bioreactor system, which is modeled after natural saline wetland ecosystems. The plant bioreactor system maximizes plant evapotranspiration to reduce wastewater volume and, concurrently, may function as a biological filter to enhance contaminant degradation and immobilization in the root/rhizosphere zone. Halophyte plant species having high salt tolerance and high transpiration rates were selected after they tested them in greenhouse experiments. Models obtained by using their greenhouse findings reduced the volume of the wastewater (up to 6% salt) by 75% in about 8 days. A field demonstration of the bioreactor, designed on the basis of the results from the greenhouse study, is successfully under way at a natural gas well site in Oklahoma. The process could offer the petroleum industry a low-cost biological alternative to existing expensive options.
Date: October 1, 1997
Creator: Negri, M.C.; Hinchman, R.R. & Mollock, J.
Partner: UNT Libraries Government Documents Department