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CALLA ENERGY BIOMASS COFIRING PROJECT

Description: The Calla Energy Biomass Project, to be located in Estill County, Kentucky is to be conducted in two phases. The objective of Phase I is to evaluate the technical and economic feasibility of cofiring biomass-based gasification fuel-gas in a power generation boiler. Waste coal fines are to be evaluated as the cofired fuel. The project is based on the use of commercially available technology for feeding and gas cleanup that would be suitable for deployment in municipal, large industrial and utility applications. Define a combustion system for the biomass gasification-based fuel-gas capable of stable, low-NOx combustion over the full range of gaseous fuel mixtures, with low carbon monoxide emissions and turndown capabilities suitable for large-scale power generation applications. The objective for Phase II is to design, install and demonstrate the combined gasification and combustion system in a large-scale, long-term cofiring operation to promote acceptance and utilization of indirect biomass cofiring technology for large-scale power generation applications.
Date: October 1, 2001
Partner: UNT Libraries Government Documents Department

Task 3.17 -- Hot-gas cleanup. Semi-annual report, July 1--December, 31, 1996

Description: The programmatic goal in advanced power systems will be to develop advanced methods for gas stream cleanup in combustion and gasification systems, using in situ and back-end technologies. The characteristics of the fuel, its ash, and sorbents will be evaluated to determine their impact on overall performance, including the reduction of gas stream contaminants. Objectives for the work to be performed under this subtask include the following: identifying effective means for hot-gas cleanup and testing in-bed sorbents for accomplishing 99% alkali capture as well as effective capture of sulfur and chlorine during PFBC; developing catalysts and effective operating ranges for removing tar from gasification process streams. Accomplishments to date and conclusions from the literature survey, thermogravimetric testing, and bench-scale testing on the capture of alkali during PFBC using in-bed sorbents are described. In addition Englehard EMcat Elite S-3699 was tested for its ability to crack coal tar produced during steam gasification of bituminous coal. Preliminary results are described.
Date: August 1997
Creator: Timpe, R. C. & Mann, M. D.
Partner: UNT Libraries Government Documents Department

Characterization and optimization of sorbents utilized for emission control during coal gasification. Final report

Description: To overcome the shortage of components required for high temperature operation required by current IGCC and PFBC systems, researchers recently have decided that the power systems can be optimized within an operation temperature range of 343 to 538 C. The findings of this research work support the use of iron oxides as an efficient, disposable hot gas desulfurization sorbent candidate to meet the temperature range of 343 to 538 C to further optimize its application for hot gas desulfurization. A parametric study was performed to characterize the controlling parameters dominating the absorption process of hydrogen sulfide by waste iron oxide as a sorbent alternative within a stringent environment with the use of simulated KRW reducing gas. The major parameters studied for hot gas desulfurization with the use of waste iron oxide; mixed in coal ash and reacted with hot sulfurized gas; in hot gas stream include (1) dust cake permeability during heavy dust loading, (2) feasibility of dust cake removal with current back pulse cleaning technology, (3) the reaction temperature, (4) the space velocity of the gas stream. Based on the parametric testing performed on hot gas desulfurization and particulate filtration, the test results of this study indicate that the simultaneous operation of hot gas desulfurization and particulate filtration is feasible. The significant savings of capital investment, system operation and maintenance justify the use of iron oxides as an excellent candidate for hot gas cleanup.
Date: July 14, 1998
Creator: Huque, Z.; Mei, D. & Zhou, J.
Partner: UNT Libraries Government Documents Department

Kinetics of hot-gas desulfurization sorbents for transport reactors

Description: Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated by many researchers to remove effectively hydrogen sulfide with various metal oxide sorbents at elevated temperatures. Various metal oxide sorbents are formulated with metal oxides such as Fe, Co, Zn, and Ti. Initial reaction kinetics of formulated sorbents with hydrogen sulfide is studied in the presence of various amounts of moisture and hydrogen at various reaction temperatures. The objectives of this research are to study initial reaction kinetics for a sorbent-hydrogen sulfide heterogeneous reaction system, to investigate effects of concentrations of hydrogen sulfide, hydrogen, and moisture on dynamic absorption of H{sub 2}S into sorbents, to understand effects of space time of reaction gas mixtures on initial reaction kinetics of the sorbent-hydrogen sulfide system, and to evaluate effects of temperature and sorbent amounts on dynamic absorption of H{sub 2}S into sorbents. Experimental data on initial reaction kinetics of hydrogen sulfide with metal oxide sorbents were obtained with a 0.83-cm{sup 3} differential reactor. The reactivity of MCRH-67 sorbent and AHI-1 was examined. These sorbents were obtained from the Research Triangle Institute (RTI). The sorbents in the form of 70 {micro}m particles are reacted with 1,000--4,000 ppm hydrogen sulfide at 450--600 C. The range of space time of reaction gas mixtures is 0.03--0.09 s. The range of reaction duration is 4--14,400 s.
Date: January 1, 2000
Creator: Kwon, K.C.
Partner: UNT Libraries Government Documents Department

Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, April--June 1995

Description: Delivery of the Antek R-6000 total sulfur analyzer and modifications of the Shimadzu GC-14A gas chromatograph are scheduled for early July. Installation and calibration of these instruments will follow shortly. The atmospheric pressure electrobalance was used during the quarter for studies of the regeneration of FeS with O{sub 2}/N{sub 2} gas mixtures. Some anomalies in the data initially obtained required adjustment of balance sensitivity, reduction of sample size, and recalibration of the air rotameter. The authors are now confident that they can routinely obtain accurate and reproducible data with this unit. Definitive tests of effects of temperature, O{sub 2} concentration, and gas flow rate will be done next quarter. The high pressure electrobalance was put into service, and calibration experiments were started. Decomposition of CuSO{sub 4}{center_dot}5H{sub 2}O produced agreement with expected results. Heating of FeS in an O{sub 2}/N{sub 2} gas stream gave results in qualitative agreement with experiments using the atmospheric pressure electrobalance. Initial tests on effects of temperature, O{sub 2} concentration, and gas flow rate on the regeneration of FeS were done. Results were generally in agreement with expectations and with previous experiments on the atmospheric apparatus. Possible problems arose when the lowest range of the air mass flow controller was used. Fluctuation of the electrobalance signal in the early part of the regeneration experiment was an additional problem. Effort during the next quarter will focus on these problems and on definitive tests for FeS regeneration at elevated pressure. The Alonized fixed bed reactor pressure vessel was successfully leak tested early in the quarter. Other components of the fixed bed reactor system continued to arrive. Construction will begin in July along with installation of the analytical instruments.
Date: July 1, 1995
Creator: Harrison, D.P.
Partner: UNT Libraries Government Documents Department

Second generation PFB for advanced power generation

Description: Research is being conducted under a United States Department of Energy (USDOE) contract to develop a new type of coal-fueled plant for electric power generation. This new type of plant-called an advanced or second-generation pressurized fluidized bed combustion (APFBC) plant-offers the promise of 45-percent efficiency (HHV), with emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. This paper summarizes the pilot plant R&D work being conducted to develop this new type of plant. Although pilot plant testing is still underway, preliminary estimates indicate the commercial plant Will perform better than originally envisioned. Efficiencies greater than 46 percent are now being predicted.
Date: November 1, 1995
Creator: Robertson, A. & Van Hook, J.
Partner: UNT Libraries Government Documents Department

Development of second-generation PFB combustion plants

Description: Research is being conducted under United States Department of Energy (USDOE) Contract DE-AC21-86MC21023 to develop a new type of coal-fueled plant for electric power generation. This new type of plant--called an Advanced or Second-generation Pressurized Fluidized Bed Combustion (APFBC) plant--offers the promise of efficiencies greater than 45 percent (HHV), with both emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. This paper summarizes the pilot-plant R&D work being conducted to develop this new type of plant and discusses a proposed design that should reduce demonstration-plant risks and costs.
Date: December 31, 1995
Creator: Robertson, A.; Domeracki, W. & Horazak, D.
Partner: UNT Libraries Government Documents Department

Sonic enhanced ash agglomeration and sulfur capture. Quarterly technical progress report, April--June 1995

Description: A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. Much research and development has been sponsored on methods for particulate emissions control and the direct injection of calcium-based sorbents to reduce SO{sub 2} emission levels. The results of this research and development indicate that both acoustic agglomeration of particulates and direct injection of sorbents have the potential to become a significant emissions control strategy. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a {open_quotes}hot flue gas cleanup{close_quotes} subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which slagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process. The goal of the program is to support the DOE mission in developing coal-fired combustion gas turbines. In particular, the MTCI proprietary process for bimodal ash agglomeration and simultaneous sulfur capture will be evaluated and developed. The technology embodiment of the invention provides for the use of standard grind, moderately beneficiated coal and WEM for firing the gas turbine with efficient sulfur capture and particulate emission control upstream of the turbine. The process also accommodates injection of alkali gettering material if necessary. The proposed technology provides for practical, reliable, and capital (and O&M) cost-effective means of protection for the gas turbine from impurities in the coal combustor effluent.
Date: August 1, 1995
Partner: UNT Libraries Government Documents Department

Hot gas cleanup test facility for gasification and pressurized combustion project. Quarterly report, October--December 1995

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 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. 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 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 this quarter.
Date: February 1, 1996
Partner: UNT Libraries Government Documents Department

Testing and technology transfer for zinc titanate sorbent in a titania matrix. Technical report, September 1, 1995--November 30, 1995

Description: For new coal gasification systems, zinc-based sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined-cycle gas turbines and high- temperature fuel cells. In general, the properties of these sorbents are considered to be very attractive, but there are still concerns about degradation of mechanical properties and sulfur capacity over many sulfidation- regeneration cycles. It is believed that containing zinc titanate in a matrix of excess titania could solve both problems, which is the objective of this project. During this quarter, plans were made for United Catalysts, Inc. to produce two batches of the sorbent using a commercial extrusion process. A subcontract was just issued to the Research Triangle Institute for sorbent characterization and for a 50- cycle performance test designed to simulate the General Electric Company`s moving-bed reactor conditions. In a parallel effort, numerous contacts were made on the technology transfer task.
Date: December 31, 1995
Creator: Swisher, J.H. & Gupta, R.P.
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Annual technical report, fiscal year 1995 (October 1994--September 1995)

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable mans 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 material 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 an gases leaving this zone pass upward to contact the feed material and continue the partial oxidation process. At the end of FY94, a limited number of pyrolysis runs were made using an oil in water emulsion of Hondo crude as the feed material. It was intended to conduct these tests in the fully integrated partial oxidation mode. At the completion of the tests, it was concluded that the reactor configuration was not suitable for handling highly coking liquid hydrocarbon feeds. The decision was made to design and build a new reactor which, in addition to a better feed injection systems, includes other design features that improve the performance and reliability of the unit. The new design is also more suitable for integrated partial oxidation testing. The design, construction, and start-up of this reactor is described.
Date: October 1, 1995
Partner: UNT Libraries Government Documents Department

Engineering development of coal-fired high-performance power systems. Technical progress report 1, July through September 1995

Description: In phase 1 of the project, a conceptual design of a coal-fired high performance power system was developed, and small scale R&D was done in critical areas of the design. The current Phase of the project includes development through the pilot plant stage, and design of a prototype plant that would be built in Phase 3. Goals have been identified that relate to the efficiency, emissions, costs and general operation of the system. The base case arrangement of the HIPPS cycle is shown in Figure 1. It is a combined cycle plant. This arrangement is referred to as the All Coal HIPPS because it does not require any other fuels for normal operation. A fluidized bed, air blown pyrolyzer converts coal into fuel gas and char. The char is fired in a high temperature advanced furnace (HITAF) which heats both air for a gas turbine and steam for a steam turbine. The air is heated up to 1400F in the HITAF, and the tube banks for heating air are constructed of alloy tubes. The fuel gas from the pyrolyzer goes to a topping combustor where it is used to raise the air entering the gas turbine to 2350F. In addition in the HITAF, steam duty is achieved with a heat recovery steam generator in the gas turbine exhaust stream and economizers in the HITAF flue gas exhaust stream. An alternative HIPPS cycle is shown in Figure 2. This arrangement uses a ceramic air heater to heat the air to temperatures above what can be achieved with alloy tubes. This arrangement is referred as the 35% natural gas HIPPS. A pyrolyzer is used as in the base case HIPPS, but the fuel gas generated is fired upstream of the ceramic air heater instead of in the topping combustor. Gas turbine air ...
Date: December 1, 1995
Partner: UNT Libraries Government Documents Department

Stabilization of spent sorbents from coal-based power generation processes. Technical report, September 1, 1995--November 30,1995

Description: The overall objective of this study is to determine the effect of implementation of the new and more stringent EPA Protocol Test Method involving sulfide containing waste, on the suitability of the oxidized spent sorbents from gasification of of high sulfur coals for disposal in landfills, and to determine the optimum operating conditions in a ``final`` hydrolysis stage for conversion of the residual calcium sulfide in these wastes to materials that are suitable for disposal in landfills. An additional objective is to study the effect of ash on the regeneration and ash-sorbent separation steps in the Spent Sorbent Regeneration Process (SSRP). To achieve these objectives, a large set of oxidized samples of sulfided calcium-based sorbents (produced in earlier ICCI-funded programs) as well as oxidized samples of gasifier discharge (containing ash and spent sorbent) are tested according to the new EPA test protocol. Samples of the oxidized spent sorbents that do not pass the EPA procedure are reacted with water and carbon dioxide to convert the residual calcium sulfide to calcium carbonate. During this quarter, samples of oxidized sulfided calcium-based sorbents, including untreated calcium sulfide-containing feed materials, were analyzed using both weak acid and more stringent strong acid tests. Preliminary analysis of the H{sub 2}S leachability test results indicate that all samples (including those that were not oxidized) pass the EPA requirement of 500 mg H{sub 2}S per kg of solid waste. However, under the strong acid test procedure, samples containing more than 2.5% calcium sulfide fail the EPA requirement.
Date: December 31, 1995
Creator: Abbassian, J. & Hill, A.H.
Partner: UNT Libraries Government Documents Department

Scale-up of advanced hot-gas desulfurization sorbents. [Semi-annual report], October 1, 1995--March 31, 1996

Description: The overall objective of this project is to develop regenerable sorbents for hot gas desulfurization in IGCC systems. The specific objective of the project is to develop durable advanced sorbents that demonstrate a strong resistance to attrition and chemical deactivation, and high activity at temperatures as low as 343 {degrees}C(650{degrees}F). A number of formulations will be prepared and screened in a 1/2-inch fixed bed reactor at high pressure (1 to 20 atm) and high temperatures using simulated coal-derived fuel-gases. Screening criteria will include, chemical reactivity, stability, and regenerability over the temperature range of 343{degrees}C to 650{degrees}C. After initial screening, at least 3 promising formulations will be tested for 25-30 cycles of absorption and regeneration. One of the superior formulations with the best cyclic performance will be selected for investigating scale up parameters. The scaled-up formulation will be tested for long term durability and chemical reactivity. Accomplishments for this period are presented for the following tasks: optimization of preparation; investigation of scale-up; and preparation of 100 lb batch.
Date: August 1, 1996
Creator: Jothimurugesan, K.; Adeyiga, A.A. & Gangwal, S.K.
Partner: UNT Libraries Government Documents Department

Pinon pine project. Annual report, January 1995--December 1995

Description: This annual report has been prepared to present the status of the Pinon Pine Project, a nominal 107 MWe (gross) coal-fired integrated gasification combined-cycle (IGCC) power plant addition to Sierra Pacific Power Company`s (SPPCo) system. This project will also serve as a demonstration project cost-shared by the U.S. Department of Energy (DOE) and SPPCo under DOE`s Clean Coal Technology (CCT) Program. The goal of the CCT Program is to demonstrate advanced coal utilization technologies that are energy efficient, reliable and able to achieve substantial reductions in emissions as compared with existing coal technologies. The Pinon Pine Project will demonstrate an IGCC system utilizing the Kellogg-Rust-Westinghouse (KRW) fluidized-bed gasification process operating in an air-blown mode with in-bed desulfurization and hot gas clean-up with a western bituminous coal as the design fuel. Testing will also be performed on a high-sulfur eastern coal. The Pinon Pine Project will be constructed and operated at SPPCo`s Tracy Power Station, an existing power generation facility located on a rural 724-acre plot approximately 17 miles east of Reno, NV. This new unit will be designated as Tracy Unit No. 4. SPPCo, the project participant, has contracted with the Foster Wheeler USA Corporation (FW USA) for the overall project management, engineering, procurement and construction of the project. FW USA in turn has subcontracted with The M.W. Kellogg Company (MWK) for the engineering and procurement of key components for the Gasifier Island.
Date: April 1, 1996
Partner: UNT Libraries Government Documents Department

Evaluation of options for CO{sub 2} capture/utilization/disposal

Description: The project objective is to develop engineering evaluations of technologies for the capture, use, and disposal of carbon dioxide (CO{sub 2}). This project emphasizes CO{sub 2}-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems. Commercially available CO{sub 2}-capture technology is providing a performance and economic baseline against which to compare innovative technologies. The intent is to provide the CO{sub 2} budget, or an {open_quotes}equivalent CO{sub 2}{close_quotes} budget associated with each of the individual energy-cycle steps in addition to process design capital and operating costs. The value used for the {open_quotes}equivalent CO{sub 2}{close_quotes} budget is 1 kg CO{sub 2}/kWhe. The base case is a 458-MW (Gross) IGCC system using an O{sub 2}-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized bed gasifier, Illinois No. 6 bituminous coal feed and low-pressure glycol sulfur removal followed by a Claus/SCOT treatment to produce a salable product. Mining, feed preparation and conversion result in a net electric power production for the entire energy cycle of 411-MW with a 0.801 kg/kWhe CO{sub 2} release rate. For comparison, the gasifier output was taken through water-gas shift and then to either low-pressure glycol or chilled methanol for H{sub 2}S recovery; low-pressure glycol or membranes for CO{sub 2} recovery; and finally either a combustion turbine or fuel cell as the topping cycle. CO{sub 2} recovery was set at 80% for all cases so that the membrane system could be compared with the glycol on a consistent basis. The combustion turbine was then fed a high hydrogen content fuel. From the IGCC plant, a 500-km pipeline took the CO{sub 2} to geological sequestering. For the optimal case, the net electric power projection was reduced by 73-MW with a 0.277-kg/kWhe CO{sub 2}, release rate (when make-up power was considered).
Date: November 1, 1995
Creator: Schmalzer, D.K. & Doctor, R.D.
Partner: UNT Libraries Government Documents Department

ENGINEERING DEVELOPMENT OF COAL-FIRED HIGH PERFORMANCE POWER SYSTEMS

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, Bechtel Corporation, University of Tennessee Space Institute and Westinghouse Electric Corporation are developing this system. In Phase 1 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). The HITAF is a pulverized fuel-fired boiler/air heater where steam is generated and gas turbine air is 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 after each experimental program has been completed, a larger scale pyrolyzer will be tested at the Power Systems Development Facility (PSDF) in Wilsonville, Al. The facility is equipped with a gas turbine and a topping combustor, and as such, will provide an opportunity to evaluate integrated pyrolyzer and turbine operation. This report addresses the areas of technical progress for this quarter. Preliminary process design was started with respect to the integrated test program at the PSDF. ...
Date: October 1, 1998
Partner: UNT Libraries Government Documents Department

BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

Description: The U.S. Department of Energy (DOE), Federal Energy Technology Center (FETC), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn{sub 2}, TiO{sub 4} or ZnTiO{sub 3}), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO{sub 2}), is currently one of the leading sorbents.
Date: April 1999
Partner: UNT Libraries Government Documents Department

SCALE-UP OF ADVANCED HOT-GAS DESULFURIZATION SORBENTS

Description: The objective of this study was to develop advanced regenerable sorbents for hot gas desulfurization in IGCC systems. The specific objective was to develop durable advanced sorbents that demonstrate a strong resistance to attrition and chemical deactivation, and high sulfidation activity at temperatures as low as 343 C (650 F). Twenty sorbents were synthesized in this work. Details of the preparation technique and the formulations are proprietary, pending a patent application, thus no details regarding the technique are divulged in this report. Sulfidations were conducted with a simulated gas containing (vol %) 10 H{sub 2}, 15 CO, 5 CO{sub 2}, 0.4-1 H{sub 2}S, 15 H{sub 2}O, and balance N{sub 2} in the temperature range of 343-538 C. Regenerations were conducted at temperatures in the range of 400-600 C with air-N{sub 2} mixtures. To prevent sulfation, catalyst additives were investigated that promote regeneration at lower temperatures. Characterization were performed for fresh, sulfided and regenerated sorbents.
Date: March 1, 1998
Creator: Jothimurugesan, K. & Gangwal, S. K.
Partner: UNT Libraries Government Documents Department

CALLA ENERGY BIOMASS COFIRING PROJECT

Description: The Calla Energy Biomass Project, to be located in Estill County, Kentucky is to be conducted in two phases. The objective of Phase I is to evaluate the technical and economic feasibility of cofiring biomass-based gasification fuel-gas in a power generation boiler. Waste coal fines are to be evaluated as the cofired fuel. The project is based on the use of commercially available technology for feeding and gas cleanup that would be suitable for deployment in municipal, large industrial and utility applications. Define a combustion system for the biomass gasification-based fuel-gas capable of stable, low-NOx combustion over the full range of gaseous fuel mixtures, with low carbon monoxide emissions and turndown capabilities suitable for large-scale power generation applications. The objective for Phase II is to design, install and demonstrate the combined gasification and combustion system in a large-scale, long-term cofiring operation to promote acceptance and utilization of indirect biomass cofiring technology for large-scale power generation applications. During this Performance Period work efforts focused on completion of the Topical Report, summarizing the design and techno-economic study of the project's feasibility. GTI received supplemental authorization A002 from DOE contracts for additional work to be performed under Phase I that will further extend the performance period until the end of February 2003. The additional scope of work is for GTI to develop the gasification characteristics of selected feedstock for the project. To conduct this work, GTI will assemble an existing ''mini-bench'' unit to perform the gasification tests. The results of the test will be used to confirm or if necessary update the process design completed in Phase Task 1.
Date: September 30, 2002
Partner: UNT Libraries Government Documents Department

Systems Analyses of Advanced Brayton Cycles For High Efficiency Zero Emission Plants

Description: Table 1 shows that the systems efficiency, coal (HHV) to power, is 35%. Table 2 summarizes the auxiliary power consumption within the plant. Thermoflex was used to simulate the power block and Aspen Plus the balance of plant. The overall block flow diagram is presented in Figure A1.3-1 and the key unit process flow diagrams are shown in subsequent figures. Stream data are given in Table A1.3-1. Equipment function specifications are provided in Tables A1.3-2 through 17. The overall plant scheme consists of a cryogenic air separation unit supplying 95% purity O{sub 2} to GE type high pressure (HP) total quench gasifiers. The raw gas after scrubbing is treated in a sour shift unit to react the CO with H{sub 2}O to form H{sub 2} and CO{sub 2}. The gas is further treated to remove Hg in a sulfided activated carbon bed. The syngas is desulfurized and decarbonized in a Selexol acid gas removal unit and the decarbonized syngas after humidification and preheat is fired in GE 7H type steam cooled gas turbines. Intermediate pressure (IP) N{sub 2} from the ASU is also supplied to the combustors of the gas turbines as additional diluent for NOx control. A portion of the air required by the ASU is extracted from the gas turbines. The plant consists of the following major process units: (1) Air Separation Unit (ASU); (2) Gasification Unit; (3) CO Shift/Low Temperature Gas Cooling (LTGC) Unit; (4) Acid Gas Removal Unit (AGR) Unit; (5) Fuel Gas Humidification Unit; (6) Carbon Dioxide Compression/Dehydration Unit; (7) Claus Sulfur Recovery/Tail Gas Treating Unit (SRU/TGTU); and (8) Power Block.
Date: November 1, 2006
Creator: Rao, A. D.; Francuz, J.; Liao, H.; Verma, A. & Samuelsen, G. S.
Partner: UNT Libraries Government Documents Department

Effect of pulsations on black liquor gasification. Progress report, July--September 1995

Description: The objective of this study is to investigate the use of pulse combustion to provide the energy required for the endothermic gasification of black liquor in a fluidized bed. In this process it is critical that the temperature remain in the small window above the gasification temperature but below the smelting temperature of the inorganic salts in the black liquor. Pulse combustors have been shown to have high heat transfer rates between the hot combustion products and the combustor tailpipe. Similarly, fluidized beds have high heat transfer rates within the bed itself, promoting temperature uniformity throughout. Typical analysis of the gasified black liquor shows there is a large percentage of combustible gases in the products of the gasification process (approximately 70%). The potential exists, therefore, for using this fuel mixture to fire the pulse combustor. This makes the entire process more efficient and may be necessary to make it economically feasible. The overall goals of this study are to determine (1) which is the limiting heat transfer rate in the process of transferring the heat from the hot combustion products to the pipe, through the pipe, from the tailpipe to the bed and then throughout the bed; i.e., whether increased heat transfer within the pulse combustor will significantly increase the overall heat transfer rate; (2) whether the temperature distribution in the bed can be maintained within the narrow temperature range required by the process without generating hot spots in the bed even if the heat transfer from the pulse combustor is significantly increased; and (3) whether the fuel gas produced during the gasification process can be used to efficiently fire the pulse combustor.
Date: December 31, 1995
Creator: Kushari, A.; Jeong, H.; Jagoda, J.I. & Zinn, B. T.
Partner: UNT Libraries Government Documents Department

High temperature electrochemical polishing of H{sub 2}S from coal gasification process streams. Quarterly report, October 1--December 31, 1997

Description: An advanced process for the separation of hydrogen sulfide from coal gasification streams through an electrochemical membrane is being perfected. H{sub 2}S is removed from a synthetic gas stream, split into hydrogen, which enriches the existing syn-gas, and sulfur, which is condensed downstream from an inert sweep gas stream. The process allows for continuous removal of H{sub 2}S without cooling the gas stream while allowing negligible pressure loss through the separator. Moreover, the process is economically attractive due to the elimination of the need for a Claus process for sulfur recovery. To this extent the project presents a novel concept for improving utilization of coal for more efficient power generation. This quarter`s research focused on fabricating LiCoO{sub 2} electrodes and then utilizing them in full cell experiments at 650 C. The cathode showed inefficient porosity to allow mass transfer of the extremely dilute hydrogen sulfide to the electrolyte interface.
Date: August 1, 1998
Creator: Winnick, J.
Partner: UNT Libraries Government Documents Department

SYNTHESIS AND CHARACTERIZATION OF CO- AND H{sub 2}S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H{sub 2}S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. During this reporting period several tri-metallic electrocatalysts were synthesized using both ultra-sonication and conventional method. These catalysts (Pt/Ru/Mo, Pt/Ru/Ir, Pt/Ru/W, Ptr/Ru/Co, and Pt/Ru/Se on carbon) were tested in MEAs. From Galvonstatic study the catalytic activity was found in the order of: Pt/Ru/Mo/C > Pt/Ru/Ir/C > Pt/Ru/W/C > Ptr/Ru/Co/C > and Pt/Ru/Se. It appears that electrocatalysts prepared by ultra-sonication process are more active compared to the conventional technique. Work is in progress to further study these catalysts for CO-tolerance in PEMFC.
Date: April 5, 2005
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department