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Optimized air staged injection for the oxidation of low calorific value gases

Description: This paper describes a simplified numerical model used for predicting an optimized air staged plug-flow combustor for low calorific value gas mixtures. The parameter used for optimization, Z, is the summed flow rates of fuel components leaving the combustor. An optimized combustor is one of a given length and input mass flux that minimizes Z. Since a mathematical proof describing the importance of global interactions remains lacking, the model employs both a ``local optimization`` procedure and a ``global optimization`` procedure. By exercising and comparing both procedures, the model shows that ``local optimization`` is sufficient to provide an optimized solution. Sensitivity of Z to deviations in air injection profile and inlet temperature is also examined.
Date: December 31, 1996
Creator: Gemmen, R.S.
Partner: UNT Libraries Government Documents Department

Catalytic Ammonia Decomposition for Coal-Derived Fuel Gases

Description: The objective of this study is to develop and demonstrate catalytic approaches for decomposing a significant percentage (up to 90 percent) of the NH{sub 3} present in fuel gas to N{sub 2} and H{sub 2} at elevated temperatures (550 to 900{degrees}C). The NH{sub 3} concentration considered in this study was {similar_to}1,800 to 2,000 ppmv, which is typical of oxygen-blown, entrained-flow gasifiers such as the Texaco coal gasifier being employed at the TECO Clean Coal Technology Demonstration plant. Catalysts containing Ni, Co, Mo, and W were candidates for the study. Before undertaking any experiments, a detailed thermodynamic evaluation was conducted to determine the concentration of NH{sub 3} in equilibrium with the Texaco gasifier coal gas. Thermodynamic evaluations were also performed to evaluate the stability of the catalytic phases (for the various catalysts under consideration) under NH3 decomposition conditions to be used in this study. Two catalytic approaches for decomposing NH{sub 3} have been experimentally evaluated. The first approach evaluated during the early phases of this project involved the screening of catalysts that could be combined with the hot-gas desulfurization sorbents (e.g., zinc titanate) for simultaneous NH{sub 3} and H{sub 2}S removal. In a commercial system, this approach would reduce capital costs by eliminating a process step. The second approach evaluated was high-temperature catalytic decomposition at 800 to 900{degrees} C. In a commercial hot-gas cleanup system this could be carried out after radiative cooling of the gas to 800 to 900{degrees}C but up stream of the convective cooler, the hot particulate filter, and the hot-gas desulfurization reactor. Both approaches were tested in the presence of up to 7,500 ppmv H{sub 2}S in simulated fuel gas or actual fuel gas from a coal gasifier.
Date: December 31, 1996
Creator: Gangwal, S.K.; Gupta, R.P.; Portzer, J.W.; Turk, B.S.; Krishnan, G.N.; Hung, S.L. et al.
Partner: UNT Libraries Government Documents Department

Development of regenerable copper-based sorbents for hot gas cleanup: Final technical report, September 1, 1995--August 31, 1996

Description: The overall objective of this study was to determine the effectiveness of the copper-chromite sorbent (developed in previous ICCI-funded projects) for longer duration application under optimum conditions in the temperature range of 550{degrees}-650{degrees}C to minimize sorbent reduction and degradation during the cyclic process. Three (3) formulations of attrition resistant granules of the copper chromite sorbent (i.e., CuCr-10, CuCr-21, and CuCr-29) as well as one (1) copper chromite sorbent in pellet form (i.e., CuCr-36) were selected for cyclic desulfurization tests. The desulfurization and regeneration capabilities of the selected formulations as well as the effects of operating parameters were determined, to identify the {open_quotes}best{close_quotes} sorbent formulation and the optimum operating conditions. The durability of the {open_quotes}best{close_quotes} sorbent formulation was determined in {open_quotes}long-term{close_quotes} multicycle tests conducted at the optimum operating conditions. The attrition resistance of the selected formulations were determined and compared with those of other sorbents, including a limestone, a dolomite, and a commercial zinc titanate sorbent. The results obtained in this study indicate that, the CuCr-29 sorbent has excellent attrition resistance and desulfurization performance, which are far superior to the commercial zinc titanate sorbents. The optimum desulfurization temperature in terms of sorbent efficiency and utilization appears to be about 600{degrees}C. Sorbent regeneration at 750{degrees}C ensured complete conversion of the copper sulfide to oxide without sulfate formation or reactivity deterioration in subsequent cycles.
Date: May 1, 1997
Creator: Abbasian, J.; Slimane, R.B. & Wangerow, J.R.
Partner: UNT Libraries Government Documents Department

Power Systems Development Facility. Quarterly report, January--March 1996

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 particular 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 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 Foster Wheeler 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.
Date: May 1, 1996
Partner: UNT Libraries Government Documents Department

Power Systems Development Facility. Quarterly report, July 1--September 30, 1996

Description: This quarterly technical progress report summarizes the work completed during the third quarter of a project entitled Hot Gas Cleanup Test Facility for Gasification and Pressurized Combustion. 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, phase 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).
Date: December 31, 1996
Partner: UNT Libraries Government Documents Department

Characterization and failure analysis of ceramic filters utilized for emission control during coal gasification. Quarterly report, July 1--September 30, 1997

Description: The research activities performed at PV A and M University in the third quarter of 1997 are summarized within. PV A and MU had performed mechanical and back pulse testing to characterize the performance of the filter and is using the process of elimination to perform the failure analysis for filters. The mechanical testing performed on the filters are categorized as follows: the acceleration testing; the vibration testing; the air jet impulse testing; and the impact testing. The major work completed in the third quarter, 1997 for filter back pulse cleaning testing included the following items: (1) the completion of the test system; (2) the procurement of particulate sample; (3) the development of a data acquisition system; (4) the filtration pressure field monitoring with the use of micro-fast pressure sensor assembly; (5) the design of a back pulse system; (6) completed a back pulse cleaning test plan; and (7) started performing parametric testing on particulate removal. The bulk of this report consists of a user`s manual for the automatic testing on instrumentation interfacing.
Date: December 31, 1997
Creator: Huque, Z. & Mei, D.: Zhou, J.
Partner: UNT Libraries Government Documents Department

High temperature electrochemical polishing of H{sub 2}S from coal gasification process streams. Quarterly progress report, April 1, 1996--June 30, 1996

Description: Coal may be used to generate electrical energy by any of several processes, most of which involve combustion or gasification. Combustion in a coal-fired boiler and power generation using a steam-cycle is the conventional conversion method; however total energy conversion efficiencies for this type of process are only slightly over 30%. Integration of a gas-cycle in the process (combined cycle) may increase the total conversion efficiency to 40%. Conversion processes based on gasification offer efficiencies above 50% H{sub 2}S is the predominant gaseous contaminant in raw coal gas. This report describes the removal of hydrogen sulfide from coal gas using an electrochemical membrane.
Date: December 31, 1997
Creator: Winnick, J.
Partner: UNT Libraries Government Documents Department

Advanced hot gas filter development. Topical report, May 1995--December 1996

Description: Porous iron aluminide was evaluated for use as a particulate filter in pressurized fluid-bed combustion (PFBC) and integrated gasification combined cycles (IGCC) with a short term test. Three alloy compositions were tested: Fe{sub 3}Al 5% chromium (FAL), Fe{sub 3}Al 2% chromium (FAS) and FeAl 0% chromium. The test conditions simulated air blown (Tampa Electric) and oxygen blown (Sierra Pacific) gasifiers with one test gas composition. Four test conditions were used with hydrogen sulfide levels varying from 783 ppm to 78,3000 ppm at 1 atmosphere along with temperatures ranging between 925 F and 1200 F. The iron aluminide was found capable of withstanding the proposed operating conditions and capable of giving years of service. The production method and preferred composition were established as seamless cylinders of Fe{sub 3}Al 2% chromium with a preoxidation of seven hours at 1472 F.
Date: December 31, 1997
Creator: Hurley, J.L. & June, M.R.
Partner: UNT Libraries Government Documents Department

ADVANCED SORBENT DEVELOPMENT

Description: The overall objective of this program was to develop regenerable sorbents for use in the temperature range of 343 to 538 C (650 to 1000 F) to remove hydrogen sulfide (H{sub 2}S) from coal-derived fuel gases in a fluidized-bed reactor. The goal was to develop sorbents that are capable of reducing the H{sub 2}S level in the fuel gas to less than 20 ppmv in the specified temperature range and pressures in the range of 1 to 20 atmospheres, with chemical characteristics that permit cyclic regeneration over many cycles without a drastic loss of activity, as well as physical, characteristics that are compatible with the fluidized bed application. This topical report focuses on the investigation directed toward preparation of zinc-based sorbents using the sol-gel approach that has been shown to require only a moderate temperature for calcination, while resulting in significantly more attrition-resistant sorbents. The sorbents prepared in this part of the investigation and the results from their evaluation in packed-bed and fluidized-bed reactors are described in this report.
Date: January 1, 2000
Creator: Abbasian, Javad
Partner: UNT Libraries Government Documents Department

CALLA ENERGY BIOMASS COFIRING PROJECT

Description: This project 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: January 1, 2001
Partner: UNT Libraries Government Documents Department

NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

Description: The objective of this program is to develop and evaluate novel sorbents for the Siemens Westinghouse Power Company's (SWPC's) ''Ultra-Clean Gas Cleaning Process'' for reducing to near-zero levels the sulfur- and chlorine-containing gas emissions and fine particulate matter (PM2.5) caused by fuel bound constituents found in carbonaceous materials, which are processed in Integrated Gasification Combined Cycle (IGCC) technologies.
Date: July 1, 2001
Creator: Abbasian, Javad
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.
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