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Simultaneous removal of H{sub 2}S and NH{sub 3} in coal gasification processes. Quarterly progress report, April 1--June 30, 1995

Description: The objective of this study is to develop advanced high-temperature coal gas desulfurization mixed-metal oxide sorbents with stable ammonia decomposition materials at 550--800 C. The specific objectives of the project are to: (1) develop combined sorbent-catalyst materials which shall be capable of removing hydrogen sulfide to less than 20 ppmv and ammonia by at least 90%; (2) carry out comparative fixed-bed studies of absorption and regeneration with various formulations of sorbent-catalyst systems and select the most promising sorbent-catalyst type; and (3) conduct long-term (at least 30 cycles) durability and chemical reactivity in the fixed-bed with the superior sorbent-catalyst. The activities of the HART 42 and HART 41 sorbent-catalysts were tested using the simulated coal gas. Figures show the H{sub 2}S removal ability, its ammonia decomposition activity, and the H{sub 2}S breakthrough profiles as a function of time. The pre-breakthrough H{sub 2}S level was below 100 ppm. Nearly complete sorbent conversion (100%) was observed at breakthrough. The HART 42 sorbent-catalysts showed moderate catalytic activity (50% average conversion) for ammonia decomposition. The average conversion decreased from 66 to 47% as the temperature was increased from 600 to 750 C for HART 41 sorbent-catalysts.
Date: October 1, 1995
Creator: Jothimurugesan, K.; Adeyiga, A.A. & Gangwal, S.K.
Partner: UNT Libraries Government Documents Department

Low-temperature catalytic gasification of food processing wastes. 1995 topical report

Description: The catalytic gasification system described in this report has undergone continuing development and refining work at Pacific Northwest National Laboratory (PNNL) for over 16 years. The original experiments, performed for the Gas Research Institute, were aimed at developing kinetics information for steam gasification of biomass in the presence of catalysts. From the fundamental research evolved the concept of a pressurized, catalytic gasification system for converting wet biomass feedstocks to fuel gas. Extensive batch reactor testing and limited continuous stirred-tank reactor tests provided useful design information for evaluating the preliminary economics of the process. This report is a follow-on to previous interim reports which reviewed the results of the studies conducted with batch and continuous-feed reactor systems from 1989 to 1994, including much work with food processing wastes. The discussion here provides details of experiments on food processing waste feedstock materials, exclusively, that were conducted in batch and continuous- flow reactors.
Date: August 1, 1996
Creator: Elliott, D.C. & Hart, T.R.
Partner: UNT Libraries Government Documents Department

Hot coal gas desulfurization with manganese based sorbents. Quarterly report, June--September 1994

Description: The focus of work being performed on hot coal gas desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt% ore + 25 wt% Al{sub 2}O{sub 3}) appears to be a strong contender to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc; hence, it is not as likely to undergo zinc-depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron; hence, the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Also manganese chlorides are much less stable and volatile than zinc chlorides. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Eighth Quarterly Report documents progress in pelletizing and testing via thermo-gravimetric analysis of individual pellet formulations of manganese ore/alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite.
Date: November 1, 1994
Creator: Hepworth, M.T. & Slimane, R.B.
Partner: UNT Libraries Government Documents Department

OPTIMIZATION OF ADVANCED FILTER SYSTEMS

Description: Reliable, maintainable and cost effective hot gas particulate filter technology is critical to the successful commercialization of advanced, coal-fired power generation technologies, such as IGCC and PFBC. In pilot plant testing, the operating reliability of hot gas particulate filters have been periodically compromised by process issues, such as process upsets and difficult ash cake behavior (ash bridging and sintering), and by design issues, such as cantilevered filter elements damaged by ash bridging, or excessively close packing of filtering surfaces resulting in unacceptable pressure drop or filtering surface plugging. This test experience has focused the issues and has helped to define advanced hot gas filter design concepts that offer higher reliability. Westinghouse has identified two advanced ceramic barrier filter concepts that are configured to minimize the possibility of ash bridge formation and to be robust against ash bridges should they occur. The ''inverted candle filter system'' uses arrays of thin-walled, ceramic candle-type filter elements with inside-surface filtering, and contains the filter elements in metal enclosures for complete separation from ash bridges. The ''sheet filter system'' uses ceramic, flat plate filter elements supported from vertical pipe-header arrays that provide geometry that avoids the buildup of ash bridges and allows free fall of the back-pulse released filter cake. The Optimization of Advanced Filter Systems program is being conducted to evaluate these two advanced designs and to ultimately demonstrate one of the concepts in pilot scale. In the Base Contract program, the subject of this report, Westinghouse has developed conceptual designs of the two advanced ceramic barrier filter systems to assess their performance, availability and cost potential, and to identify technical issues that may hinder the commercialization of the technologies. A plan for the Option I, bench-scale test program has also been developed based on the issues identified. The two advanced barrier filter systems ...
Date: April 30, 1998
Creator: Newby, R.A.; Bruck, G.J.; Alvin, M.A. & Lippert, T.E.
Partner: UNT Libraries Government Documents Department

DEVELOPMENT OF AN ADHESIVE CANDLE FILTER SAFEGUARD DEVICE

Description: In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal conversion. Two main types of systems employ these turbines: those based on pressurized fluidized-bed combustors and those based on integrated gasification combined cycles. In both systems, suspended particulates must be cleaned from the gas stream before it enters the turbine so as to prevent fouling and erosion of the turbine blades. To produce the cleanest gas, barrier filters are being developed and are in use in several facilities. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the particulates on the surface. The three main configurations of the barrier filters are candle, cross-flow, and tube filters. Both candle and tube filters have been tested extensively. They are composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer on the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle and individual elements can fail, allowing particulates to pass through the hole left by the filter element and erode the turbine. Preventing all failure of individual ceramic filter elements is not possible at the present state of development of the technology. Therefore, safeguard devices (SGDs) must be employed to prevent the particulates streaming through occasional broken filters from reaching the turbine. However, the SGD must allow for the free passage of gas when it is not activated. Upon breaking of a filter, the SGD must either mechanically close or quickly plug with filter dust to prevent additional dust from reaching the ...
Date: January 1, 2002
Creator: Hurley, John P.; Henderson, Ann K.; Nowok, Jan W. & Swanson, Michael L.
Partner: UNT Libraries Government Documents Department

A Feasibility Study for Recycling Used Automotive Oil Filters In A Blast Furnace

Description: This feasibility study has indicated that of the approximately 120,000 tons of steel available to be recycled from used oil filters (UOF's), a maximum blast furnace charge of 2% of the burden may be anticipated for short term use of a few months. The oil contained in the most readily processed UOF's being properly hot drained and crushed is approximately 12% to 14% by weight. This oil will be pyrolized at a rate of 98% resulting in additional fuel gas of 68% and a condensable hydrocarbon fraction of 30%, with the remaining 2% resulting as carbon being added into the burden. Based upon the writer's collected information and assessment, there appears to be no operational problems relating to the recycling of UOF's to the blast furnace. One steel plant in the US has been routinely charging UOF's at about 100 tons to 200 tons per month for many years. Extensive analysis and calculations appear to indicate no toxic consideration as a result of the pyrolysis of the small contained oil ( in the 'prepared' UOFs) within the blast furnace. However, a hydrocarbon condensate in the ''gasoline'' fraction will condense in the blast furnace scrubber water and may require additional processing the water treatment system to remove benzene and toluene from the condensate. Used oil filters represent an additional source of high quality iron units that may be effectively added to the charge of a blast furnace for beneficial value to the operator and to the removal of this resource from landfills.
Date: January 21, 2002
Creator: Smailer, Ralph M.; Dressel, Gregory L. & Hill, Jennifer Hsu
Partner: UNT Libraries Government Documents Department

Task 3.17 - Hot-Gas Cleanup

Description: No abstract prepared.
Date: August 1, 1997
Creator: Timpe, Ronald C. & Mann, Michael D.
Partner: UNT Libraries Government Documents Department

Engineering development of coal-fired high-performance power systems. Technical report, July - September 1996

Description: A High Performance Power System (HIPPS) is being developed. This system is a coal-fired, combined cycle plant with indirect heating of gas turbine air. Foster Wheeler Development Corporation and a team consisting of Foster Wheeler Energy Corporation, AlliedSignal Aerospace Equipment Systems, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase I of the project, a conceptual design of a commercial plant was developed. Technical and economic analyses indicated that the plant would meet the goals of the project which include a 47 percent efficiency (HHV) and a 10 percent lower cost of electricity than an equivalent size PC plant. The concept uses a pyrolyzation process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). It is a pulverized fuel-fired boiler/airheater where steam and gas turbine air are indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine. The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and then a pilot plant with integrated pyrolyzer and char combustion systems will be tested. In this report, progress in the pyrolyzer pilot plant preparation is reported. The results of extensive laboratory and bench scale testing of representative char are also reported. Preliminary results of combustion modeling of the char combustion system are included. There are also discussions of the auxiliary systems that are planned for the char combustion system pilot plant and the status of the ...
Date: November 1, 1996
Partner: UNT Libraries Government Documents Department

Energy and environmental research emphasizing low-rank coal -- Task 3.10, Gas separation and hot-gas cleanup

Description: Catalytic gasification of coal to produce H{sub 2}-, CO-, and CH{sub 4}-rich mixtures of gases for consumption in molten carbonate fuel cells is currently under development; however, to optimize the fuel cell performance and extend its operating life, it is desired to separate as much of the inert components (i.e., CO{sub 2} and N{sub 2}) and impurities (i.e., H{sub 2}S and NH{sub 3}) as possible from the fuel gas before it enters the fuel cell. In addition, the economics of the integrated gasification combined cycle (IGCC) can be improved by separating as much of the hydrogen as possible from the fuel, since hydrogen is a high-value product. Researchers at the Energy and Environmental Research Center (EERC) and Bend Research, Inc., investigated pressure-driven membranes as a method for accomplishing this gas separation and hot-gas cleanup. These membranes are operated at temperatures as high as 800 C and at pressures up to 300 psig. They have very small pore sizes that separate the undesirable gases by operating in the Knudsen diffusion region of mass transport or in the molecular sieving region of mass transport phenomena. In addition, H{sub 2} separation through a palladium metal membrane proceeds via a solution-diffusion mechanism for atomic hydrogen. This allows the membranes to exhibit extremely high selectivity for hydrogen separation. Specific questions to be answered in this project include: what are the effects of membrane properties (i.e., surface area, pore size, and coating thickness) on permeability and selectivity of the desired gases; what are the effects of operating conditions (i.e., temperature, pressure, and flow rate) on permeability and selectivity; what are the effects of impurities (i.e., small particulate, H{sub 2}S, HCl, NH{sub 3}, etc.) on membrane performance?
Date: August 1, 1995
Creator: Swanson, M.L.
Partner: UNT Libraries Government Documents Department

Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly progress report, July 15, 1995--September 15, 1995

Description: The Morgantown Energy Technology Center (METC) of the U.S. Department of Energy (DOE) is actively pursuing the development of reliable and cost-effective processes to clean coal gasifier gases for application to integrated gasification combined cycle (IGCC) and molten carbonate fuel cell (MCFC) power plants. A large portion of gas cleanup research has been directed towards hot gas desulfurization using Zn-based sorbents. However, zinc titinate sorbents undergo reduction to the metal at temperatures approaching 700{degrees}C. In addition, sulfate formation during regeneration leads to spalling of reactive 293 surfaces. Due to zinc-based sorbent performance, METC has shown interest in formulating and testing manganese-based sorbents. Westmoreland and Harrison evaluated numerous candidate sulfur sorbents and identified Mn as a good candidate. Later, Turkdogan and Olsson tested manganese-based sorbents which demonstrated superior desulfurization capacity under high temperatures, and reducing conditions. Recently, Ben-Slimane and Hepworth conducted several studies on formulating Mn-sorbents and desulfurizing a simulated fuel gas. Although thermodynamics predicts higher over-pressures with Mn verses Zn, under certain operating conditions Mn-based sorbents may obtain < 20 ppmv. In addition, the manganese-sulfur-oxygen (Mn-S-O) system does not reduce to the metal under even highly reducing gases at high temperatures (550-900{degrees}C). Currently, many proposed IGCC processes include a water quench prior to desulfurization. This is for two reasons; limitations in the process hardware (1000{degrees}C), and excessive Zn-based sorbent loss (about 700{degrees}C). With manganese the water quench is obviated due to sorbent loss, as Mn-based sorbents have been shown to retain reactivity under cycling testing at 900{degrees}C. This reduces system hardware, and increases thermal efficiency while decreasing the equilibrium H{sub 2}S over-pressure obtainable with a manganese sorbent.
Date: September 15, 1995
Creator: Hepworth, M.T.
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Quarterly technical report, April 1--June 30, 1996

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, byproducts, and other low value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed to pyrolysis and steam gasification in a circulating bed of solids. Carbon residues formed during pyrolysis, and metals in the feed, are captured by the circulating solids which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the gasification process. Tests were conducted in the Transport Reactor Test Unit (TRTU) to study gasification and combustion of Rose Bottoms using the spent FCC (Fluid Catalytic Cracker) catalyst as the circulating medium at temperature of 1,690 F. The Rose (Residuum Oil Supercritical Extraction) bottoms was produced in the Kellogg`s Rose unit. Studies were done in the Bench Scale Reactor Unit (BRU) to characterize petroleum coke with respect to pyrolysis and agglomeration tendency upon heating to 1,800 F. Studies were conducted in the CFS (Cold Flow Simulator) to determine the various aeration flowrates required for satisfactory circulation of petroleum coke in the TRTU. Results from these studies are presented in this report. A dry solid feed system was developed and tested for use in the fourth quarter.
Date: July 12, 1996
Creator: Katta, S.; Henningsen, G.; Lin, Y.Y. & Agrawal, R.
Partner: UNT Libraries Government Documents Department

A regenerable sorbent injection/filtration process for H{sub 2}S removal from hot gas

Description: The operational characteristics of a hot gas desulfurization process involving regenerable sorbent injection and its subsequent collection with a ceramic filtration device were studied utilizing a bench-scale transport reactor. Hydrogen sulfide removal from simulated hot gas was evaluated as a function of both zinc oxide-based sorbent physical and chemical characteristics and various process parameters. In addition, the sorbent capture efficiency and regenerability of the ceramic filtration device were evaluated, and regeneration of sulfided sorbents via injection into an oxidizing gas was studied. For both sorbent sulfidation and spent sorbent regeneration, gas-solid reaction occurred both in the duct and within layers of partially reacted sorbent captured by the ceramic filter. Very high sulfur removal efficiencies were obtained only in highly reducing hot gas compositions at or above about 700 C, using stoichiometric ratio (defined as ZnO/H{sub 2}S ratio) values of about 1.5, and sorbent particles of about 20 {micro}m or less in diameter. Under such conditions, the experimental data indicated that reaction of H{sub 2}S with zinc vapor formed by reduction of zinc oxide contributed appreciably to sulfur removal. Negligible zinc loss from the hot zone of the reactor was detected, apparently due to rapid formation of zinc sulfide product layers on zinc oxide particles. The ceramic filtration devices captured 100% of all sorbent particles and were fully regenerable over periods of several tens of injection/backpulse cleaning cycles. Spent sorbent could be fully regenerated rapidly at 850 C without problems due to exotherm generation.
Date: December 31, 1996
Creator: Higgins, R.J.; Ji, W.; Connors, M.J.; Jones, J.F. & Goldsmith, R.L.
Partner: UNT Libraries Government Documents Department

Comprehensive Report to Congress Clean Coal Technology Program: Clean power from integrated coal/ore reduction

Description: This report describes a clean coal program in which an iron making technology is paired with combined cycle power generation to produce 3300 tons per day of hot metal and 195 MWe of electricity. The COREX technology consists of a metal-pyrolyzer connected to a reduction shaft, in which the reducing gas comes directly from coal pyrolysis. The offgas is utilized to fuel a combined cycle power plant.
Date: October 1, 1996
Partner: UNT Libraries Government Documents Department

Kinetics of mn-based sorbents for hot gas desulfurization: Task 2 - exploratory experimental studies. Quarterly report, March 15, 1996--June 15, 1996

Description: The objective of this project is to develop a pellet formulation which is capable of achieving low sulfur partial pressures and a high capacity for sulfur, loaded from a hot fuel gas and which is readily regenerable. Furthermore the pellet must be strong for potential use in a fluidized bed and regenerable over many cycles of loading and regeneration. Regeneration should be in air or oxygen-depleted air to produce a high-concentration sulfur dioxide. Fixed-bed tests were conducted with several formulations of manganese sesquioxide and titania, and alumina They were subject to a simplified fuel gas of the oxygen-blown Shell type spiked with a 30,000ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2mm diameter pellets was typically 12 lbs per pellet and 4 lbs per pellet, respectively. For the most favorable of the formulations tested and under the criteria of break-through at less than 100ppmv H2S and loading temperatures of 500{degrees}C and an empty-bed space velocity of 4,000 per hour, breakthrough occurred an effective loading of sulfur of 27 to 29% over 5 loading and regeneration cycles. At 90% of this saturation condition, the observed level of H{sub 2}S was below 10ppmv. For regeneration, a temperature of 900{degrees}C is required to dissociate the sulfide into sulfur dioxide using air at atmospheric pressure. The mean sulfur dioxide concentration which is achieved during regeneration is 8% with empty-bed space velocities of 700/hr. TGA tests on individual pellets indicate that bentonite is not desirable as a bonding material and that Mn/Ti ratios higher than 7:1 produce relatively non-porous pellets. Whereas the reactivity is rapid below 12% conversion, the kinetics of conversion decreases significantly above this level. This observation may be the result of plugging of the pellet pores with sulfided product creating inaccessible pore volumes or alternately an increase m diffusional ...
Date: June 12, 1996
Creator: Hepworth, M.T. & Berns, J.
Partner: UNT Libraries Government Documents Department

Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high-temperature furnace (HITAF): Volume 4. Final report

Description: An outgrowth of our studies of the FWDC coal-fired high performance power systems (HIPPS) concept was the development of a concept for the repowering of existing boilers. The initial analysis of this concept indicates that it will be both technically and economically viable. A unique feature of our greenfields HIPPS concept is that it integrates the operation of a pressurized pyrolyzer and a pulverized fuel-fired boiler/air heater. Once this type of operation is achieved, there are a few different applications of this core technology. Two greenfields plant options are the base case plant and a plant where ceramic air heaters are used to extend the limit of air heating in the HITAF. The greenfields designs can be used for repowering in the conventional sense which involves replacing almost everything in the plant except the steam turbine and accessories. Another option is to keep the existing boiler and add a pyrolyzer and gas turbine to the plant. The study was done on an Eastern utility plant. The owner is currently considering replacing two units with atmospheric fluidized bed boilers, but is interested in a comparison with HIPPS technology. After repowering, the emissions levels need to be 0.25 lb SO{sub x}/MMBtu and 0.15 lb NO{sub x}/MMBtu.
Date: May 1, 1996
Partner: UNT Libraries Government Documents Department

Hot Gas Cleanup Test Facility for Gasification and Pressurized Combustion Project. Quarterly report, April--June 1996

Description: The objective of this project is to evaluate hot gas particle control technologies using coal-derived as streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed Include the integration of the particulate control devices into coal utilization systems, on-line cleaning, techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing, Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: 1 . Carbonizer/Pressurized Circulating, Fluidized Bed Gas Source; 2. Hot Gas Cleanup Units to mate to all gas streams; 3. Combustion Gas Turbine; 4. Fuel Cell and associated gas treatment. This expansion to the Hot Gas Cleanup Test Facility is herein referred to as the Power Systems Development Facility (PSDF). The major emphasis during, this reporting period was continuing, the detailed design of the FW portion of the facility towards completion and integrating the balance-of-plant processes and particulate control devices (PCDS) into the structural and process designs. Substantial progress in construction activities was achieved during the quarter. Delivery and construction of the process structural steel is complete and the construction of steel for the coal preparation structure is complete.
Date: December 31, 1996
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Quarterly report, July 1--September 30, 1996

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, byproducts, and other low value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed to pyrolysis and steam gasification in a circulating bed of solids. Carbon residue formed during pyrolysis, as well as metals in the feed, are captured by the circulating solids which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the gasification process. Tests were conducted in the Transport Reactor Test Unit (TRTU) to study gasification and combustion of Rose Bottoms solids using the spent FCC (Fluid Catalytic Cracker) catalyst as the circulating medium and petroleum coke at temperature of 1,750 F. The Rose (Residuum Oil Supercritical Extraction) bottoms was produced in the Kellogg`s Rose unit. A dry solid feed system developed previously was used to feed petroleum coke and Rose Bottoms. Studies were also done in the Bench Scale Reactor Unit (BRU) to investigate partial oxidation and gasification of petroleum coke over temperature range of 1,800 F to 2,100 F. Results obtained in the BRU and TRTU on petroleum coke formed the basis to develop a flowsheet to process this material in a transport reactor. Results from these studies are presented in this report.
Date: October 18, 1996
Creator: Katta, S.; Henningsen, G.; Lin, Y.Y. & Agrawal, R.
Partner: UNT Libraries Government Documents Department

Bench-scale demonstration of hot-gas desulfurization technology. Quarterly report, January 1--March 31, 1998

Description: At the start of the current project, the DSRP (Direct Sulfur Recovery Process) technology was at the bench-scale development stage with a skid-mounted system ready for field testing. The process had been extended to fluidized-bed operation in the Stage 1 reactor. A preliminary economic study for a 100 MW plant in which the two-stage DSRP was compared to conventional processes indicated the economic attractiveness of the DSRP. Through bench-scale development, both fluidized-bed zinc titanate and DSRP technologies have been shown to be technically and economically attractive. The demonstrations prior to the start of this project, however, had only been conducted using simulated (rather than real) coal gas and simulated regeneration off-gas. Thus, the effect of trace contaminants in real coal gases on the sorbent and DSRP catalyst was not known. Also, the zinc titanate desulfurization unit and DSRP had not been demonstrated in an integrated manner. The overall goal of this project is to continue further development of the zinc titanate desulfurization and DSRP technologies by scale-up and field testing (with actual coal gas) of the zinc titanate fluidized-bed reactor system, and the Direct Sulfur Recovery Process.
Date: December 31, 1998
Partner: UNT Libraries Government Documents Department

Conceptual design and optimization of a 1-1/2 generation PFBC plant task 14. Topical report

Description: The economics and performance of advanced pressurized fluidized bed (PFBC) cycles developed for utility applications during the last 10 years (especially the 2nd-Generation PFBC cycle) are projected to be favorable compared to conventional pulverized coal power plants. However, the improved economics of 2nd-Generation PFBC cycles are accompanied by the perception of increased technological risk related to the pressurized carbonizer and its associated gas cleanup systems. A PFBC cycle that removed the uncertainties of the carbonizer while retaining the high efficiency and low cost of a 2nd-Generation PFBC cycle could improve the prospects for early commercialization and pave the way for the introduction of the complete 2nd-Generation PFBC cycle at some later date. One such arrangement is a PFBC cycle with natural gas topping combustion, referred to as the 1.5-Generation PFBC cycle. This cycle combines the advantages of the 2nd-Generation PFBC plant with the reduced risk associated with a gas turbine burning natural gas, and can potentially be part of a phased approach leading to the commercialization of utility 2nd-Generation PFBC cycles. The 1.5-Generation PFBC may also introduce other advantages over the more complicated 2nd-Generation PFBC system. This report describes the technical and economic evaluation of 1.5-Generation PFBC cycles for utility or industrial power generation.
Date: December 1, 1994
Creator: White, J.S.; Witman, P.M.; Harbaugh, L.; Rubow, L.N. & Horazak, D.A.
Partner: UNT Libraries Government Documents Department

Hot Gas Cleanup Test Facility for gasification and pressurized combustion. Quarterly report, October--December 1994

Description: The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: carbonizer/pressurized circulating fluidized bed gas source; hot gas cleanup units to mate to all gas streams; combustion gas turbine; and fuel cell and associated gas treatment. The major emphasis during this reporting period was continuing the detailed design of the facility and integrating the particulate control devices (PCDs) into structural and process designs. Substantial progress in underground construction activities was achieved during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. MWK equipment at the grade level and the first tier are being set in the structure.
Date: February 1, 1995
Partner: UNT Libraries Government Documents Department

Indirectly heated fluidized bed biomass gasification using a latent heat ballast

Description: The objective of this study is to improve the heating value of gas produced during gasification of biomass fuels using an indirectly heated gasifier based on latent heat ballasting. The latent heat ballast consists of lithium fluoride salt encased in tubes suspended in the reactor. The lithium fluoride has a melting point that is near the desired gasification temperature. With the ballast a single reactor operating in a cyclic mode stores energy during a combustion phase and releases it during a pyrolysis phase. Tests were carried out in a fluidized bed reactor to evaluate the concept. The time to cool the reactor during the pyrolysis phase from 1,172 K (1,650 F) to 922 K (1,200 F) increased 102% by use of the ballast system. This extended pyrolysis time allowed 33% more biomass to be gasified during a cycle. Additionally, the total fuel fraction pyrolyzed to produce useful gas increased from 74--80%. Higher heating values of 14.2 to 16.6 MJ/Nm{sup 3} (382--445 Btu/scf) on a dry basis were obtained from the ballasted gasifier.
Date: December 31, 1998
Creator: Pletka, R.; Brown, R. & Smeenk, J.
Partner: UNT Libraries Government Documents Department

Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, October--December 1994

Description: The goal is the development of simpler and economically superior processing of regenerable sorbents used for control of hydrogen sulfide in hot, high-pressure gas streams in advanced power generating systems. The improved processing will produce an elemental sulfur byproduct. Progress during the past quarter was limited by delays in identifying an appropriate analytical instrument for measuring the concentration of sulfur species (S{sub x}(g), H{sub 2}S, and SO{sub 2} in the regeneration product gas. The ability to carry out this analysis on a real-time basis is an important component of the overall project and we feel that a satisfactory gas analysis procedure should be available before forging ahead with other experimental activities. The primary accomplishment, therefore, was the completion and submission of the Task 3 Project Plan. This plan, which assumed a satisfactory solution to sulfur analysis problem, is included in this quarterly report.
Date: January 1, 1995
Creator: Harrison, D.P.
Partner: UNT Libraries Government Documents Department