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Sorbents for mercury removal from flue gas

Description: A review of the various promoters and sorbents examined for the removal of mercury from flue gas is presented. Commercial sorbent processes are described along with the chemistry of the various sorbent-mercury interactions. Novel sorbents for removing mercury from flue gas are suggested. Since activated carbons are expensive, alternate sorbents and/or improved activated carbons are needed. Because of their lower cost, sorbent development work can focus on base metal oxides and halides. Additionally, the long-term sequestration of the mercury on the sorbent needs to be addressed. Contacting methods between the flue gas and the sorbent also merit investigation.
Date: January 1998
Creator: Granite, Evan J.; Hargis, Richard A. & Pennline, Henry W.
Partner: UNT Libraries Government Documents Department

Testing and analysis of METC10 sorbent

Description: Development of a suitable regenerable sorbent is a major barrier issue in the Hot Gas Cleanup program for Integrated Gasification Combined Cycle systems. This has been a challenging problem for the last 20 years. Many of the sorbents developed in prior work did not retain their reactivity and physical integrity during repeated sulfidation/regeneration cycles. This paper is a report on a promising sorbent (METC10) developed at the Morgantown Energy Technology Center (METC) which has demonstrated sustained reactivity and physical integrity during repeated sulfidation and regeneration cycles. METC10 sorbent was tested in a low pressure (260 kPa/23 psig) fixed-bed reactor at 538{degrees}C (1,OOO{degrees}F) with simulated air blown K Rust Westinghouse (KRW) coal gas. The sorbent was subjected to 3.5 sulfidation/regeneration cycles using steam as the regeneration diluent. There were no appreciable changes in reactivity during the 3.5 cycles and spalling or other physical deterioration was not observed. Sorbent pellets, which were prepared by a commercial vendor (United Catalysts, Inc.) to METC specifications, were exposed to fifty sulfidation/regeneration cycles using conditions typical of the Tampa Electric Company (TECO) Clean Coal Technology (CCT) demonstration project. After the fiftieth sulfidation cycle, both the sulfur loading value (more than 6 lb/ft{sup 3}) and the attrition (less than 5 wt%) satisfied the requirements necessary for the TECO/CCT project. These sorbent pellets were also tested with real coal gas for 240 hours in a moving bed reactor at General Electric (GE) company. Sulfur absorption was according to the sorbent movement rate and the attrition rate was very low during 240 hours of the pilot plant operation.
Date: December 31, 1996
Creator: Siriwardane, R.V.
Partner: UNT Libraries Government Documents Department

Advanced Sulfur Control Processing

Description: The primary objective of this project is to determine the feasibility of an alternate concept for the regeneration of high temperature desulfurization sorbents in which elemental sulfur, instead of SO{sub 2}, is produced. If successful, this concept will eliminate or alleviate problems caused by the highly exothermic nature of the regeneration reaction, the tendency for metal sulfate formation, and the need to treat the regeneration off-gas to prevent atmospheric SO{sub 2}, emissions. Iron and cerium-based sorbents were chosen on the basis of thermodynamic analysis to determine the feasibility of elemental sulfur production. The ability of both to remove H{sub 2}S during the sulfidation phase is less than that of zinc-based sorbents, and a two-stage desulfurization process will likely be required. Preliminary experimental work used electrobalance reactors to compare the relative rates of reaction of O{sub 2} and H{sub 2}O with FeS. More detailed studies of the regeneration of FeS as well as the sulfidation of CeO{sub 2} and regeneration of Ce{sub 2}O{sub 2}S are being carried out in a laboratory-scale fixed-bed reactor equipped with a unique analytical system which permits semi-continuous analysis of the distribution of elemental sulfur, H{sub 2}S, and SO{sub 2} in the reaction product gas.
Date: December 31, 1996
Creator: Gangwal, S.K.; Portzer, J.W.; Turk, B.S. & Gupta, R.
Partner: UNT Libraries Government Documents Department

Advanced Low-Temperature Fluid Bed Sorbents

Description: This paper discusses the results obtained in an ongoing study geared towards developing advanced mixed-metal oxide sorbents for desulfurization of coal-derived fuel gases in the temperature range of 350 to 550{degrees}C. The paper focuses on the study related to the development of durable sorbents suitable for fluidized-bed application and addresses thermodynamic considerations, sulfidation kinetics, regenerability, and the physical and chemical characteristics of a number of novel sorbents.
Date: December 31, 1996
Creator: Abbasian, J.; Slimane, R. B. & Wangerow, J. R.
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

Sorbent Development for Low-Temperature Moving-Bed Desulfurization

Description: In this program, the effort is geared towards developing advanced mixed-metal oxide sorbents for desulfurization in moving-bed systems in the temperature rang 343-538{degrees}C (650-1000{degrees}F) where technical viability and process efficiency result in lower overall process costs. In addition a cost assessment and a market plan for large-scale fabrication of sorbents will be developed. As an optional task, a long-term bench-scale testing of the best moving-bed sorbent formulation will conducted. The sorbents must have chemical characteristics that permit cyclic desulfurization and regeneration over many cycles without a drastic loss of activity. The sorbents must be capable of reducing the hydrogen sulfide level in the fuel gas to less than 20 ppm in the specified temperature range and pressures in the range of 1 to 20 atmospheres. In addition, they must also have physical characteristics that are compatible with the selected reactor, e.g. pellet size/shape. This paper discusses in more detail recent developments in the fabrication and use of doped zinc titanate sorbents for moving-bed configurations at temperatures below 538{degrees}C (1000{degrees}F).
Date: December 31, 1996
Creator: Ayala, R.E.; Venkataramani, V.S.; Chuck, T.L. & Gupta, R.P.
Partner: UNT Libraries Government Documents Department

Composition modification of zinc titanate sorbents for hot gas desulfurization. Quarterly report, 1 December 1994--28 February 1995

Description: For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. A screening study was completed during the second quarter in which Ni, Cr, Cu, Mg, and Al were evaluated as dopants in zinc titanate. Measurements that were made include solubility, crush strength, and sulfidation-regeneration behavior in a thermogravimetric analyzer. A formulation containing Cr showed the most promise. It and other formulations containing Cr will be emphasized during the remainder of the year. Fixed bed experiments will start during the third quarter.
Date: December 31, 1995
Creator: Swisher, J.H. & Datta, R.K.
Partner: UNT Libraries Government Documents Department

METC`s pilot-scale hot-gas desulfurization Process Development Unit

Description: 801The Morgantown Energy Technology Center (METC) has designed and is currently constructing an on-site, hot gas desulfurization (HGD) Process Development Unit (PDU). The PDU is designed to use regenerable solid metal oxide sorbents that absorb hydrogen sulfide from high-temperature, high-pressure simulated coal-gasification fuel gas that is generated by a METC-designed syngas generator. The simulated coal gas is a mixture of partially combusted natural gas, water, carbon dioxide and hydrogen sulfide. PDU process conditions will be representative of anticipated commercial applications in terms of temperatures, pressures, compositions, velocities, and sorbent cycling. The PDU supports the Integrated Gasification Combined Cycle (IGCC) mission at METC by providing a test bed for development of IGCC cleanup systems that offer low capital cost, operating costs, and costs of electricity. METC intends to develop additional industrial involvement opportunities as the project progresses towards operations. Objectives The primary objectives of the PDU are to: (1) fill the gap between small-scale testing and large-scale demonstration projects by providing a cost effective test site for transport and fluid-bed desulfurization reactor and sorbent development, (2) demonstrate sorbent suitability over a wide range of parameters and (3) generate significant information on process control for transport and fluidized bed based desulfurization. PDU data is expected to be used to optimize process performance by expanding the experience for larger-scale demonstration projects, such as Sierra Pacific Power Company`s Clean Coal Technology project.
Date: December 31, 1996
Creator: McMillian, M.H. & Bissett, L.A.
Partner: UNT Libraries Government Documents Department

Manganese-based sorbents for coal gas desulfurization

Description: The intent of this study is to perform a preliminary screening on a particular Mn-based sorbent, CST-939 (from Chemetals), for hot gas desulfurization. The purpose of the preliminary screening is to determine which temperature and type of coal gas this sorbent demonstrates the greatest capacity and efficiency for sulfur removal. The following conclusions were made from the data collected on the CST-939 sorbent: The sorbent efficiency and capacity are much greater at 343{degrees}C (650{degrees}F) than at 871{degrees}C (1,600{degrees}F). The sorbent efficiency and capacity are much greater in the presence of the more highly-reducing Shell gas than with the less-reducing KRW gas. The sorbent showed tremendous capacity for sulfur pickup, with actual loadings as high as 21 weight percent. Oxidative regeneration at 871{degrees}C (1,600{degrees}F) appeared to decompose sulfate; however, unusually high SO{sub 2} release during the second sulfidations and/or reductive regenerations indicated incomplete regeneration. The average crush strength of the reacted sorbent did not indicate any loss of strength as compared to the fresh sorbent. Superior sorbent performance was obtained in the presence of simulated Shell gas at 538{degrees}C (1,000{degrees}F).
Date: December 31, 1996
Creator: Gasper-Galvin, L.D.; Fisher, E.P. & Goyette, W.J.
Partner: UNT Libraries Government Documents Department

Scale-up of advanced hot-gas desulfurization sorbents. Technical progress report No. 3, April 1, 1996--September 30, 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.
Date: October 14, 1996
Creator: Jothimurugesan, K. & Gangwal, S.K.
Partner: UNT Libraries Government Documents Department

Advanced Hot-Gas Desulfurization Sorbents

Description: The objective of this project is to develop advanced hot-gas desulfurization sorbents for relatively low temperature application that show stable and high sulfidation reactivity at 343 to 538 {degrees}C. A number of zinc-based formulations will be prepared and screened for testing in a fixed-bed reactor at high pressure (1 to 20 atm) and high temperatures using simulated coal-derived fuel gases. One of the superior formulations will be tested for long- term durability and chemical reactivity in the reactor. To prevent sulfation, catalyst additives will be investigated, which would promote a lower regeneration temperature.
Date: December 31, 1996
Creator: Jothimurugesan, K.; Adeyiga, A. & Gangwal, S.K.
Partner: UNT Libraries Government Documents Department

Fluidized-bed testing of Z-SORB III sorbent

Description: Phillips Petroleum Company (PPCo) successfully developed a fluidizable version of their proprietary Z-SORB sorbent. Z-SORB sorbent is a ZnO-based regenerable sorbent for removing hydrogen sulfide (H{sub 2}S) and carbonyl sulfide (COS). RTI conducted a life-cycle test on this sorbent in the high-temperature, high-pressure (HTHP) semi-batch fluidized-bed reactor. This test consisted of 50 cycles of sulfidation and regeneration to demonstrate the long-term chemical reactivity and mechanical strength of the Z-SORB sorbent. A simulated air-blown gasifier coal gas was used at 20 atm and 538 {degree}C (1,000{degree}F). The Z-SORB sorbent exhibited excellent sulfur removal capability; the prebreakthrough H{sub 2}S levels were below the detection limit of the analyzer (<10 ppmv). The sulfur capacity of the sorbent at breakthrough (500 ppM H{sub 2}S in reactor exit gas) was 20.2 g S/100 g sorbent in Cycle 1 and was 10 g S/100 g sorbent in Cycle 50. The sorbent loss from the reactor due to fines generation was small. While no significant change in particle size was observed, the bulk density increased by 8 percent over 51 cycles. The attrition resistance of the sorbent after the 51 cycles was slightly lower than the fresh material. The thermogravimetric analyzer (TGA) tests on fresh and reacted sorbents confirmed the sulfur capacity decline in the bench tests; however, the TGA data indicated no change in the H{sub 2}S absorption rate between the fresh and reacted sorbents. The regeneration of the sulfided sorbent was successfully carried out using 2 to 2.5 percent 0{sub 2} in N{sub 2} at a temperature of 649 to 704{degree}C (1,200 to 1,300{degree}F) with no evidence of sulfate formation. Overall, the sorbent exhibited good performance.
Date: August 1, 1994
Creator: Gupta, R. P.; Gangwal, S. K. & Khare, G. P.
Partner: UNT Libraries Government Documents Department

Trace-level mercury removal from surface water

Description: Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water.
Date: June 1, 1998
Creator: Klasson, K.T. & Bostick, D.T.
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

Direct sulfur recovery during sorbent regeneration. Final report

Description: The objective of this research project was to improve the direct elemental sulfur yields that occur during the regeneration of SO{sub 2}-saturated MgO-vermiculite sorbents (MagSorbents) by examining three approaches or strategies. The three approaches were regeneration-gas recycle, high-pressure regeneration, and catalytic reduction of the SO{sub 2} gas using a new catalyst developed by Research Triangle Institute (RTI). Prior to the project, Sorbent Technologies Corporation (Sorbtech) had developed a sorbent-regeneration process that yielded directly a pure elemental sulfur product. In the process, typically about 25 to 35 percent of the liberated S0{sub 2} was converted directly to elemental sulfur. The goal of this project was to achieve a conversion rate of over 90 percent. Good success was attained in the project. About 90 percent or more conversion was achieved with two of the approaches that were examined, regeneration-gas recycle and use of the RTI catalyst. Of these approaches, regeneration-gas recycle gave the best results (essentially 100 percent conversion in some cases). In the regeneration-gas recycle approach, saturated sorbent is simply heated to about 750{degree}C in a reducing gas (methane) atmosphere. During heating, a gas containing elemental sulfur, water vapor, H{sub 2}S, S0{sub 2}, and C0{sub 2} is evolved. The elemental sulfur and water vapor in the gas stream are condensed and removed, and the remaining gas is recycled back through the sorbent bed. After several recycles, the S0{sub 2} and H{sub 2}S completely disappear from the gas stream, and the stream contains only elemental sulfur, water vapor and C0{sub 2}.
Date: August 1, 1993
Creator: Nelson, S.G. & Little, R.C.
Partner: UNT Libraries Government Documents Department

Reactivity of Metal Oxide Sorbents for Removal of H{sub 2}S

Description: Removal of hydrogen sulfide contained in hot coal gases produced from integrated gasification combined cycle power generation systems is required to protect downstream combustion turbines from being corroded with sulfur compounds. Removal of sulfur compounds from hot coal gas products is investigated by using various metal oxide sorbents and membrane separation methods. The main requirements of these metal oxide sorbents are durability and high sulfur loading capacity during absorption-regeneration cycles. In this research, durable metal oxide sorbents were formulated. Reactivity of the formulated metal oxide sorbents with simulated coal gas mixtures was examined to search for an ideal sorbent formulation with a high-sulfur loading capacity suitable for removal of hydrogen sulfide from coal gases. The main objectives of this research are to formulate durable metal oxide sorbents with high-sulfur loading capacity by a physical mixing method, to investigate reaction kinetics on the removal of sulfur compounds from coal gases at high temperature and pressure, to study reaction kinetics on the regeneration of sulfided sorbents, to identify effects of hydrogen partial pressures and moisture on equilibrium/dynamic absorption of hydrogen sulfide into formulated metal oxide sorbents as well as initial reaction rates of H{sub 2}S with formulated metal oxide sorbents, and to evaluate intraparticular diffusivity of H{sub 2}S into formulated sorbents at various reaction conditions. The metal oxide sorbents such as TU-1, TU-19, TU-24, TU-25 and TU-28 were formulated with zinc oxide powder as an active sorbent ingredient, bentonite as a binding material and titanium oxide as a supporting metal oxide.
Date: December 31, 1996
Creator: Kwon, K.C. & Crowe, E.R.
Partner: UNT Libraries Government Documents Department

Kinetics of Mn-based sorbents for hot coal gas desulfurization: Task 2, Exploratory experimental studies: Single pellet tests; Rate mechanism analysis. Quarterly report, June 15, 1996--September 15, 1996

Description: Currently, the Morgantown Energy Technology Center, Department of Energy (DOE/METC) is actively investigating alternative hot fuel gas desulfurization sorbents for application to the Integrated Gasification Combined Cycle (IGCC). A sorbent must be highly active towards sulfur at high temperatures and pressures, and under varying degrees of reducing atmospheres. Also, it must regenerate nearly ideally to maintain activity over numerous cycles. Furthermore, regeneration must yield a sulfur product which is economically recoverable directly or indirectly. Several metal oxides have been investigated as regenerable sorbents for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot fuel gases. MnO was shown to have an intrinsic reaction rate approximately one order of magnitude greater than the rate or reaction with either CaO or ZnO and two orders of magnitude greater than the reaction rate with V{sub 2}0{sub 3}. Manganese also shows desulfurization potential in the temperature range of 600-700{degrees}C where metal oxides currently known to be reactive with H{sub 2}S are unsatisfactorily. In response to stability difficulties of single and binary metal oxide sorbents, increasing effort is being directed towards incorporation of an inert component into sorbent formulation as witnessed by the various Zn-titanates. Primarily, the inert component increases pore structure integrity while stabilizing the active metal oxide against reduction. This report will address testing of Mn-based sorbents in an ambient pressure fixed-bed reactor. Steady-state H{sub 2}S concentrations and breakthrough times will be presented.
Date: September 11, 1996
Creator: Hepworth, M.T.
Partner: UNT Libraries Government Documents Department

Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 12, December 1, 1993--February 28, 1994

Description: The NOXSO process is a dry, post-combustion flue gas treatment technology which uses a regenerable sorbent to simultaneously adsorb sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) from the flue gas of a coal-fired utility boiler. In the process, the SO{sub 2} is reduced to sulfur by-product and the NO{sub x} is reduced to nitrogen and oxygen. It is predicted that the process can economically remove 90% of the acid rain precursor gases from the flue gas stream in a retrofit or new facility. The objective of the NOXSO Demonstration Project is to design, construct, and operate a flue gas treatment system utilizing the NOXSO process. The effectiveness of the process will be demonstrated by achieving significant reductions in emissions of sulfur and nitrogen oxides. In addition, sufficient operating data will be obtained to confirm the process economics and provide a basis to guarantee performance on a commercial scale. The project is presently in the project definition and preliminary design phase. Data obtained during pilot plant testing which was completed on July 30, 1993 is being incorporated in the design of the commercial size plant. A suitable host site to demonstrate the NOXSO process on a commercial scale is presently being sought. The plant general arrangement has been revised to incorporate principles used in the design of fluidized catalytic cracking (FCC) plants. A NOXSO plant availability analysis was prepared using operating experience from the recently completed pilot plant as a basis. The impact of water desorption in the sorbent heater and water adsorption in the sorbent cooler has been quantified and incorporated into the NOXSO process simulator. NOXSO process economics has been updated based on the present design. Capital cost for a 500 MW plant designed to remove 98% of the SO{sub 2} and 85% of the NO{sub x} ...
Date: December 31, 1994
Partner: UNT Libraries Government Documents Department

Hot Coal Gas Desulfurization With Manganese-Based Sorbents

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 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 30,000 ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2 mm 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 100 ppmv H{sub 2}S and loading temperatures of 5000 {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 10 ppmv. For regeneration, a temperature of 9000 {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 decreased significantly above this level. This observation may be the result of plugging of the pellet pores with sulfided product creating inaccessible pore ...
Date: December 31, 1996
Creator: Berns, J.J. & Hepworth, M.T.
Partner: UNT Libraries Government Documents Department

Commercial demonstration of the NOXSO SO{sub 2}/NO{sub x} removal flue gas cleanup system. Quarterly technical progress report No. 3, September 1--November 30, 1991

Description: The NOXSO Process is a dry, post-combustion flue gas treatment technology which uses a regenerable sorbent to simultaneously adsorb sulfur dioxide and nitrogen oxides from the flue gas of a coal-fired utility boiler. In the process, the SO{sub 2} is reduced to elemental sulfur and the NO{sub x} is reduced to nitrogen and oxygen. It is predicted that the process can economically remove 90% of the acid rain precursor gases from the flue gas stream in a retrofit or new facility. The objective of the NOXSO Demonstration Project is to design, construct, and operate a flue gas treatment system utilizing the NOXSO Process at Ohio Edison`s Niles Plant Unit 1. The effectiveness of the process will be demonstrated by achieving significant reductions in emissions of sulfur and nitrogen oxides. In addition, sufficient operating data will be obtained to confirm the process economics and provide a basis to guarantee performance on a commercial scale. Ohio Edison`s Niles Plant Unit 1 generates 115 MW of electricity and 275,000 scfm of flue gas while burning 3.5% sulfur coal.
Date: December 31, 1991
Partner: UNT Libraries Government Documents Department

A pilot-scale Process Development Unit for transport and fluid-bed hot-gas desulfurization

Description: The Morgantown Energy Technology Center (METC) has designed and is currently constructing an on-site, hot gas desulfurization (HGD) Process Development Unit (PDU). The PDU is designed to use regenerable solid metal oxide sorbents that absorb hydrogen sulfide from high-temperature, high-pressure simulated coal-gasification fuel gas that is generated by a METC designed syngas generator. The simulated coal gas is a mixture of partially combusted natural gas, water, carbon dioxide, and hydrogen sulfide. PDU process conditions will be representative of anticipated commercial applications in terms of temperatures, pressures, compositions, velocities, and sorbent cycling. The PDU supports the Integrated Gasification Combined Cycle (IGCC) mission at METC by providing a test bed for development of IGCC cleanup systems that offer low capital cost, operating costs, and costs of electricity. METC intends to develop additional industrial involvement opportunities as the project progresses towards operations. The primary objectives of the PDU are to (1) fill the gap between small-scale testing and large-scale demonstration projects by providing a cost effective test site for transport and fluid-bed desulfurization reactor and sorbent development, (2) demonstrate sorbent suitability over a wide range of parameters, and (3) generate significant information on process control for transport and fluidized bed based desulfurization. PDU data is expected to be used to optimize process performance by expanding the experience for larger scale demonstration projects such as Sierra Pacific Power Company`s Clean Coal Technology project.
Date: September 1, 1996
Creator: McMillian, M.H. & Bissett, L.A.
Partner: UNT Libraries Government Documents Department

Design, construction, and operation of a life-cycle test system for the evaluation of flue gas cleanup processes

Description: The Pittsburgh Energy Technology Center of the US Department of Energy has designed, constructed, and operated a Life-Cycle Test Systems (LCTS) that will be used primarily for the investigation of dry, regenerable sorbent flue gas cleanup processes. Sorbent continuously cycles from an absorber reactor where the pollutants are removed from the flue gas, to a regenerator reactor where the activity of the spent sorbent is restored and a usable by-product stream of gas is produced. The LCTS will initially be used to evaluate the Moving-Bed Copper Oxide Process by determining the effects of various process parameters on SO{sub 2} and NO{sub x} removals. The purpose of this paper is to document the design rationale and details, the reactor/component/instrument installation, and the initial performance of the system. Although the Moving-Bed Copper Oxide Process will be investigated initially, the design of the LCTS evolved to make the system a multipurpose, versatile research facility. Thus, the unit can be used to investigate various other processes for pollution abatement of SO{sub 2}, NO{sub x}, particulates, air toxics, and/or other pollutants.
Date: December 1, 1995
Creator: Pennline, H.W.; Yeh, James T.; Hoffman, J.S.; Longton, E.J.; Vore, P.A.; Resnik, K.P. et al.
Partner: UNT Libraries Government Documents Department

Investigation on durability and reactivity of promising metal oxide sorbents during sulfidation and regeneration. Quarterly report, January--March 1995

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 high pressures and high temperatures. Metal oxides such as zinc titanate oxides, zinc ferrite oxide, copper oxide, manganese oxide and calcium oxide, were found to be promising sorbents in comparison with other removal methods such as membrane separations and reactive membrane separations. Some metal oxide sorbents exhibited the quite favorable performance in terms of attrition resistance and sulfur capacity. Removal reaction of H{sub 2}S from coal gas mixtures with ZT-4 or other promising sorbents of fine solid particles, and regeneration reaction of sulfur-loaded sorbents will be carried on in a batch reactor or a continuous differential reactor. The objectives of this research project are to find intrinsic initial reaction kinetics for the metal oxide-hydrogen sulfide heterogeneous reaction system, to obtain effects of concentrations of coal gas components such as hydrogen, carbon monoxide, carbon dioxide, oxygen, nitrogen and moisture on equilibrium reaction rate constants of the reaction system at various reaction temperatures and pressures, to identify regeneration kinetics of sulfur-loaded metal oxide sorbents, and to formulate promising metal oxide sorbents for the removal of sulfur from coal gas mixtures. Promising durable metal oxide sorbents of high-sulfur-absorbing capacity will be formulated by mixing active metal oxide powders with inert metal oxide powders and calcining these powder mixtures, or impregnating active metal oxide sorbents on supporting metal oxide matrixes.
Date: March 1, 1995
Creator: Kwon, K.C.
Partner: UNT Libraries Government Documents Department