Development of Advanced Hot-gas Desulfurization Processes

Development of Advanced Hot-gas Desulfurization Processes PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Advanced integrated gasification combined cycle (IGCC) power plants nearing completion, such as Sierra-Pacific, employ a circulating fluidized-bed (transport) reactor hot-gas desulfurization (HGD) process that uses 70-180 [mu]m average particle size (aps) zinc-based mixed-metal oxide sorbent for removing H2S from coal gas down to less than 20 ppmv. The sorbent undergoes cycles of absorption (sulfidation) and air regeneration. The key barrier issues associated with a fluidized-bed HGD process are chemical degradation, physical attrition, high regeneration light-off (initiation) temperature, and high cost of the sorbent. Another inherent complication in all air-regeneration-based HGD processes is the disposal of the problematic dilute SO2 containing regeneration tail-gas. Direct Sulfur Recovery Process (DSRP), a leading first generation technology, efficiently reduces this SO2 to desirable elemental sulfur, but requires the use of 1-3 % of the coal gas, thus resulting in an energy penalty to the plant. Advanced second-generation processes are under development that can reduce this energy penalty by modifying the sorbent so that it could be directly regenerated to elemental sulfur. The objective of this research is to support the near and long term DOE efforts to commercialize the IGCC-HGD process technology. Specifically we aim to develop: optimized low-cost sorbent materials with 70-80 [mu]m average aps meeting all Sierra specs; attrition resistant sorbents with 170 [mu]m aps that allow greater flexibility in the choice of the type of fluidized-bed reactor e.g. they allow increased throughput in a bubbling-bed reactor; and modified fluidizable sorbent materials that can be regenerated to produce elemental sulfur directly with minimal or no use of coal gas The effort during the reporting period has been devoted to development of an advanced hot-gas process that can eliminate the problematic SO2 tail gas and yield elemental sulfur directly using a sorbent containing a combination of zinc and iron oxides.

Development of Advanced Hot-gas Desulfurization Processes

Development of Advanced Hot-gas Desulfurization Processes PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Book Description
Advanced integrated gasification combined cycle (IGCC) power plants nearing completion, such as Sierra-Pacific, employ a circulating fluidized-bed (transport) reactor hot-gas desulfurization (HGD) process that uses 70-180 [mu]m average particle size (aps) zinc-based mixed-metal oxide sorbent for removing H2S from coal gas down to less than 20 ppmv. The sorbent undergoes cycles of absorption (sulfidation) and air regeneration. The key barrier issues associated with a fluidized-bed HGD process are chemical degradation, physical attrition, high regeneration light-off (initiation) temperature, and high cost of the sorbent. Another inherent complication in all air-regeneration-based HGD processes is the disposal of the problematic dilute SO2 containing regeneration tail-gas. Direct Sulfur Recovery Process (DSRP), a leading first generation technology, efficiently reduces this SO2 to desirable elemental sulfur, but requires the use of 1-3 % of the coal gas, thus resulting in an energy penalty to the plant. Advanced second-generation processes are under development that can reduce this energy penalty by modifying the sorbent so that it could be directly regenerated to elemental sulfur. The objective of this research is to support the near and long term DOE efforts to commercialize the IGCC-HGD process technology. Specifically we aim to develop: optimized low-cost sorbent materials with 70-80 [mu]m average aps meeting all Sierra specs; attrition resistant sorbents with 170 [mu]m aps that allow greater flexibility in the choice of the type of fluidized-bed reactor e.g. they allow increased throughput in a bubbling-bed reactor; and modified fluidizable sorbent materials that can be regenerated to produce elemental sulfur directly with minimal or no use of coal gas The effort during the reporting period has been devoted to development of an advanced hot-gas process that can eliminate the problematic SO2 tail gas and yield elemental sulfur directly using a sorbent containing a combination of zinc and iron oxides.

Development of Advanced Hot-gas Desulfurization Sorbents

Development of Advanced Hot-gas Desulfurization Sorbents PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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ENGINEERING EVALUATION OF HOT-GAS DESULFURIZATION WITH SULFUR RECOVERY.

ENGINEERING EVALUATION OF HOT-GAS DESULFURIZATION WITH SULFUR RECOVERY. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 159

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Engineering evaluations and economic comparisons of two hot-gas desulfurization (HGD) processes with elemental sulfur recovery, being developed by Research Triangle Institute, are presented. In the first process, known as the Direct Sulfur Recovery Process (DSRP), the SO2 tail gas from air regeneration of zinc-based HGD sorbent is catalytically reduced to elemental sulfur with high selectivity using a small slipstream of coal gas. DSRP is a highly efficient first-generation process, promising sulfur recoveries as high as 99% in a single reaction stage. In the second process, known as the Advanced Hot Gas Process (AHGP), the zinc-based HGD sorbent is modified with iron so that the iron portion of the sorbent can be regenerated using SO2 . This is followed by air regeneration to fully regenerate the sorbent and provide the required SO2 for iron regeneration. This second-generation process uses less coal gas than DSRP. Commercial embodiments of both processes were developed. Process simulations with mass and energy balances were conducted using ASPEN Plus. Results show that AHGP is a more complex process to operate and may require more labor cost than the DSRP. Also capital costs for the AHGP are higher than those for the DSRP. However, annual operating costs for the AHGP appear to be considerably less than those for the DSRP with a potential break-even point between the two processes after just 2 years of operation for an integrated gasification combined cycle (IGCC) power plant using 3 to 5 wt% sulfur coal. Thus, despite its complexity, the potential savings with the AHGP encourage further development and scaleup of this advanced process.

Advanced Sulfur Control Concepts for Hot Gas Desulfurization Technology

Advanced Sulfur Control Concepts for Hot Gas Desulfurization Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Book Description
The objective of this project is to develop a hot-gas desulfurization process scheme for control of H2S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.

Development of a Hot-gas Desulfurization System for IGCC Applications

Development of a Hot-gas Desulfurization System for IGCC Applications PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 19

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Book Description
Integrated gasification combined cycle (IGCC) power plants are being advanced worldwide to produce electricity from coal because of their superior environmental performance, economics, and efficiency in comparison to conventional coal-based power plants. One key component of an advanced IGCC power plant is a hot-gas desulfurization system employing regenerable sorbents. To carry out hot-gas desulfurization in a fluidized-bed reactor, it is necessary that the sorbents have high attrition resistance, while still maintaining high chemical reactivity and sulfur absorption capacity. Also, efficient processes are needed for the treatment of SO2-containing regeneration off-gas to produce environmentally benign waste or useful byproducts. A series of durable zinc titanate sorbents were formulated and tested in a bench-scale fluidized-bed reactor system. Reactive sorbents were developed with addition resistance comparable to fluid-bed cracking (FCC) catalysts used in petroleum refineries. In addition, progress continues on the development of the Direct Sulfur Recovery Process (DSRP) for converting SO2 in the regeneration off-gas to elemental sulfur. Plans are under way to test these bench-scale systems at gasifier sites with coal gas. This paper describes the status and future plans for the demonstration of these technologies.

Desulfurization of Hot Coal Gas

Desulfurization of Hot Coal Gas PDF Author: Aysel T. Atimtay
Publisher: Springer Science & Business Media
ISBN: 3642589774
Category : Technology & Engineering
Languages : en
Pages : 409

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Book Description
Economic and environmental requirements for advanced power generating systems demand the removal of corrosive and other sulfurous compounds from hot coal gas. After a brief account of the world energy resources and an overview of clean coal technologies, a review of regenerable metal oxide sorbents for cleaning the hot gas is provided. Zinc oxide, copper oxide, calcium oxide, manganese oxide based as well as supported and mixed metal oxide sorbents are treated. Performance analysis of these sorbents, effects of various parameters on the desulfurization efficiency, kinetics of sulfidation and regeneration reactions, sulfiding and regeneration mechanisms are discussed. Two chapters present recent results in the direct production of elemental sulfur from regeneration or SO2-rich gases.

Advanced Sulfur Control Concepts in Hot-gas Desulfurization Technology

Advanced Sulfur Control Concepts in Hot-gas Desulfurization Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 45

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Book Description
The topical report describes the results of Phase 2 research to determine the feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Many of the contaminants present in coal emerge from the gasification process in the product gas. Much effort has gone into the development of high temperature metal oxide sorbents for removal of H2S from coal gas. The oxides of zinc, iron, manganese, and others have been studied. In order for high temperature desulfurization to be economical it is necessary that the sorbents be regenerated to permit multicycle operation. Current methods of sorbent regeneration involve oxidation of the metal sulfide to reform the metal oxide and free the sulfur as SO2. An alternate regeneration process in which the sulfur is liberated in elemental form is desired. Elemental sulfur, which is the typical feed to sulfuric acid plants, may be easily separated, stored, and transported. Although research to convert SO2 produced during sorbent regeneration to elemental sulfur is on-going, additional processing steps are required and the overall process will be more complex. Clearly, the direct production of elemental sulfur is preferred. Desulfurization utilizing a cerium oxide based sorbent is discussed.

Advanced Sulfur Control Concepts in Hot-gas Desulfurization Technology

Advanced Sulfur Control Concepts in Hot-gas Desulfurization Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

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Book Description
This topical report de-scribes the results of Phase 1 research performed during the first six months of a three-year contract to study the feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Much effort has gone into the development of a high-temperature meal oxide sorbent process for removal of H2S from the coal gas. A number of sorbents based upon metals such as zinc, iron, manganese and others have been studied. In order for high temperature desulfurization to be economical it is necessary that the sorbents be regenerated to permit multicycle operation. Current methods of sorbent regeneration involve oxidation of the metal sulfide to reform the metal oxide and free the sulfur as SO2. An alternate regeneration process in which the sulfur is liberated in elemental form is preferable. The overall objective of the current research is to study simpler and economically superior processing of known sorbents capable of producing elemental sulfur during regeneration. This topical report summarizes the first steps of this effort. A literature search has been completed to identify possible regeneration concepts and to collect relevant thermodynamic, kinetic, and process data. Three concepts involving reaction with SO2, partial oxidation using an O2 - H2O mixture, and steam regeneration have been identified. The first two concepts result in the direct production of elemental sulfur while H2S is the product of steam regeneration. This concept is of potential interest, however, since existing Claus technology can be used to convert H2S to elemental sulfur. Following the literature search, a thermodynamic analysis, based upon free-energy minimization was carried out to evaluate candidate sorbents for possible use with the three regeneration concepts.

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 782

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Department of the Interior and Related Agencies Appropriations for 1996: Secretary of Energy

Department of the Interior and Related Agencies Appropriations for 1996: Secretary of Energy PDF Author: United States. Congress. House. Committee on Appropriations. Subcommittee on Department of the Interior and Related Agencies
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 876

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