Download or read book ZnO based Regenerable Sulfur Sorbents for Fluid bed transport Reactor Applications written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for producing regenerable sulfur sorbents in which a support material precursor is mixed with isopropanol and a first portion of deionized water at an elevated temperature to form a sol mixture. A metal oxide precursor comprising a metal suitable for use as a sulfur sorbent is dissolved in a second portion of deionized water, forming a metal salt solution. The metal salt solution and the sol mixture are mixed with a sol peptizing agent while heating and stirring, resulting in formation of a peptized sol mixture. The metal oxide precursor is dispersed substantially throughout the peptized sol mixture, which is then dried, forming a dry peptized sol mixture. The dry peptized sol mixture is then calcined and the resulting calcined material is then converted to particles.
Download or read book New ZnO Based Regenerable Sorbents for Fluid Bed Transport Reactor Applications written by Javad Abbasian and published by . This book was released on 2000 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New ZnO Based Regenerable Sulfur Sorbents for Fluid Bed written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of the ongoing sorbent development work at GTI is the advancement to the demonstration stage of a promising ZnO-TiO2 sulfur sorbent that has been developed under DCCA/ICCI and DOE/NETL sponsorship. This regenerable sorbent has been shown to possess an exceptional combination of excellent chemical reactivity, high effective capacity for sulfur absorption, high resistance to attrition, and regenerability at temperatures lower than required by typical zinc titanates.
Download or read book Durable Zinc Oxide Based Regenerable Sorbents for Desulfurization of Syngas in a Fixed Bed Reactor written by and published by . This book was released on 2001 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fixed-bed regenerable desulfurization sorbent, identified as RVS-land developed by researchers at the U.S. Department of Energy's National Energy Technology Laboratory, was awarded the R & D 100 award in 2000 and is currently offered as a commercial product by Sued-Chemie Inc. An extensive testing program for this sorbent was undertaken which included tests at a wide range of temperatures, pressures and gas compositions both simulated and generated in an actual gasifier for sulfidation and regeneration. This testing has demonstrated that during these desulfurization tests, the RVS-1 sorbent maintained an effluent H2S concentration of 5 ppmv at temperatures from 260 to 600 C (500-1100 F) and pressures of 203-2026 kPa(2 to 20 atm) with a feed containing 1.2 vol% H2S. The types of syngas tested ranged from an oxygen-blown Texaco gasifier to biomass-generated syngas. The RVS-1 sorbent has high crush strength and attrition resistance, which, unlike past sorbent formulations, does not decrease with extended testing at actual at operating conditions. The sulfur capacity of the sorbent is roughly 17 to 20 wt.% and also remains constant during extended testing (25 cycles). In addition to H2S, the RVS-1 sorbent has also demonstrated the ability to remove dimethyl sulfide and carbonyl sulfide from syngas. During regeneration, the RVS-1 sorbent has been regenerated with dilute oxygen streams (1 to 7 vol% O2) at temperatures as low as 370 C (700 F) and pressures of 304-709 kPa(3 to 7 atm). Although regeneration can be initiated at 370 C (700 F), regeneration temperatures in excess of 538 C (1000 F) were found to be optimal. The presence of steam, carbon dioxide or sulfur dioxide (up to 6 vol%) did not have any visible effect on regeneration or sorbent performance during either sulfidation or regeneration. A number of commercial tests involving RVS-1 have been either conducted or are planned in the near future. The RVS-1 sorbent has been tested by Epyx, Aspen Systems and McDermott Technology (MTI), Inc for desulfurization of syngas produced by reforming of hydrocarbon liquid feedstocks for fuel cell applications. The RVS-1 sorbent was selected by MTI over other candidate sorbents for demonstration testing in their 500-kW ship service fuel cell program. It was also possible to obtain sulfur levels in the ppbv range with the modified RVS-1 sorbent.
Download or read book Long Life ZnO TiO2 and Novel Sorbents written by and published by . This book was released on 1996 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combined cycles (combinations of a gas turbine and a steam bottoming cycle) are the most efficient power generation technology, while coal is the lowest cost fuel. Therefore, the combination of Coal Gasifiers and Combined Cycles is predicted to be the lowest cost source of baseload electric power in the next decade. In a GCC, the sulfur and particulates are removed from the gasifier gases before they enter the turbine combuster. While H2S (and COS/CS2) can be removed effectively by cooling hot gases down to near room temperature and scrubbing them with an aqueous amine solution, removing the H2S without cooling the gases (i.e., hot gas cleanup) is more advantageous. The leading hot gas sulfur absorbent uses a regenerable zinc oxide (ZnO) based sorbent, zinc titanate (Zn2TiO4 and/or ZnTiO3), to remove the H2S and other sulfur compounds from the hot coal gases. The zinc absorbs H2S, forming zinc sulfide (ZnS); ZnS is then regenerated with oxygen (air), releasing the sulfur as a concentrated stream of SO2. The SO2 can be converted into sulfuric acid, sulfur, or reacted with calcium carbonate to form calcium sulfate (gypsum). The sorbent may be operated in a fluidized bed reactor, transport reactor, or moving bed reactor. Both the fluidized-bed and the transport reactor use two separate reactors; one absorbs H2S COS and CS2 and converts the ZnO to ZnS; the second bed regenerates the sorbent with air converting the ZnS back to ZnO and producing SO2 (Figure 1); the sorbent moves between the two reactors to carry sulfur out of the absorber and return regenerated sorbent. Fluidized bed and transport reactors circulate very small particles at high gas velocity. The high gas-solid contact area of very small particles rapidly transfers both heat and mass within the reactor. The fluidized bed and transport reactor hot gas cleanup desulfurization systems are very similar and the sorbent particles are also of the same size (i.e., 50 to 400 micron). While there are several differences between the two reactors, the one which most affects the sorbent is the operation of the regenerator: fluidized bed reactors operate with diluted air while transport reactors operate with undiluted air.
Download or read book Fluidized bed Testing of Z SORB III Sorbent written by and published by . This book was released on 1994 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 (H2S) 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 °C (1,000°F). The Z-SORB sorbent exhibited excellent sulfur removal capability; the prebreakthrough H2S levels were below the detection limit of the analyzer (
Download or read book Highly Attrition Resistant Zinc Oxide Based Sorbents for H2S Removal by Spray Drying Technique written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Primary issues for the fluidized-bed/transport reactor process are high attrition resistant sorbent, its high sorption capacity and regenerability, durability, and cost. The overall objective of this project is the development of a superior attrition resistant zinc oxide-based sorbent for hot gas cleanup in integrated coal gasification combined cycle (IGCC). Sorbents applicable to a fluidized-bed hot gas desulfurization process must have a high attrition resistance to withstand the fast solid circulation between a desulfurizer and a regenerator, fast kinetic reactions, and high sulfur sorption capacity. The oxidative regeneration of zinc-based sorbent usually initiated at greater than 600 C with highly exothermic nature causing deactivation of sorbent as well as complication of sulfidation process by side reaction. Focusing on solving the sorbent attrition and regenerability of zinc oxide-based sorbent, we have adapted multi-binder matrices and direct incorporation of regeneration promoter. The sorbent forming was done with a spray drying technique that is easily scalable to commercial quantity.
Download or read book Bench Scale Development of Fluidized Bed Spray Dried Sorbents written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Successful development of regenerable mixed-metal oxide sorbents for removal of reduced sulfur species (such as H[sub 2]S and COS) from coal-derived fuel gas streams at high=temperature, high-pressure (HTHP) conditions is a key to commercialization of the integrated-gasification-combined-cycle (IGCC) power systems. Among the various available coal-to-electricity pathways, IGCC power plants have the most potential with high thermal efficiency, simple system configuration, low emissions of SO[sub 2], NO[sub x] and other contaminants, modular design, and low capital cost. Due to these advantages, the power plants of the 21st century are projected to utilize IGCC technology worldwide. Sorbents developed for sulfur removal are primarily zinc oxide-based inorganic materials, because of their ability to reduce fuel gas sulfur level to a few parts-per-million (ppm). This project extends the prior work on the development of fluidizable zinc titanate particles using a spray-drying technique to impart high reactivity and attrition resistance. Specific objectives are to develop highly reactive and attrition-resistant zinc titanate sorbents in 40- to 150-[mu]m particle size range for transport reactor applications using semicommercial- to full commercial-scale spray dryers, to transfer sorbent production technology to private sector, and to provide technical support for Sierra Pacific's Clean Coal Technology Demonstration plant and METC's hot-gas desulfurization process development unit (PDU), both employing a transport reactor system.
Download or read book Fluidized bed Sorbents written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this project are to identify and demonstrate methods for enhancing long-term chemical reactivity and attrition resistance of zinc oxide-based mixed metal-oxide sorbents for desulfurization of hot coal-derived gases in a high-temperature, high-pressure (HTHP) fluidized-bed reactor. In this program, regenerable ZnO-based mixed metal-oxide sorbents are being developed and tested. These include zinc ferrite, zinc titanate, and Z-SORB sorbents. The Z-SORB sorbent is a proprietary sorbent developed by Phillips Petroleum Company (PPCo).
Download or read book Hydrogen and Syngas Production and Purification Technologies written by Ke Liu and published by John Wiley & Sons. This book was released on 2010-01-07 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the timely topic of fuel cells and hydrogen-based energy from its fundamentals to practical applications Serves as a resource for practicing researchers and as a text in graduate-level programs Tackles crucial aspects in light of the new directions in the energy industry, in particular how to integrate fuel processing into contemporary systems like nuclear and gas power plants Includes homework-style problems
Download or read book Gasification written by Christopher Higman and published by Elsevier. This book was released on 2011-08-30 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gasification is a process that if properly utilized can transform the world in which we live. Comprehensive in its coverage, this second edition continues the tradition of the first by providing engineers and scientists with an up-to-date overview of commercial processes and applications relevant to today's demands. Gasification, 2nd edition is expanded and provides more detail on the integration issues for current generation, state-of-the-art Integrated Gasification Combined Cycles (IGCC); CO2 capture in the IGCC context addressing the issues of pre-investment and retrofitting as well as defining what the term "CO2 capture ready" might mean in practice; issues of plant reliability, availability and maintainability (RAM) including as evaluation of feedback from existing plants; implementation of fuel cell technology in IGCC concepts. All statistics, processes and projects, including descriptions of a number of processes not covered in the previous edition. - Up-to-date overview of commercial processes - Covers applications relevant to today's demands - Addresses the issues of pre-investment and retrofitting - Provides more detail on the integration issues for Integrated Gasification
Download or read book Desulfurization of Hot Coal Gas written by Aysel T. Atimtay and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Thermochemical Processing of Biomass written by Robert C. Brown and published by John Wiley & Sons. This book was released on 2011-03-16 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermochemical pathways for biomass conversion offer opportunities for rapid and efficient processing of diverse feedstocks into fuels, chemicals and power. Thermochemical processing has several advantages relative to biochemical processing, including greater feedstock flexibility, conversion of both carbohydrate and lignin into products, faster reaction rates, and the ability to produce a diverse selection of fuels. Thermochemical Processing of Biomass examines the large number of possible pathways for converting biomass into fuels, chemicals and power through the use of heat and catalysts. The book presents a practical overview of the latest research in this rapidly developing field, highlighting the fundamental chemistry, technical applications and operating costs associated with thermochemical conversion strategies. Bridging the gap between research and practical application, this book is written for engineering professionals in the biofuels industry, as well as academic researchers working in bioenergy, bioprocessing technology and chemical engineering. Topics covered include: Combustion Gasification Fast Pyrolysis Hydrothermal Processing Upgrading Syngas and Bio-oil Catalytic Conversion of Sugars to Fuels Hybrid Thermochemical/Biochemical Processing Economics of Thermochemical Conversion For more information on the Wiley Series in Renewable Resources, visit www.wiley.com/go/rrs
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Regenerable Sorbent Injection filtration Process for H sub 2 Removal from Hot Gas written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The operational characteristics of a hot gas desulfurization process involving regenerable sorbent injection and its subsequent collection with a ceramic filtration device were studied utilizing a bench-scale transport reactor. Hydrogen sulfide removal from simulated hot gas was evaluated as a function of both zinc oxide-based sorbent physical and chemical characteristics and various process parameters. In addition, the sorbent capture efficiency and regenerability of the ceramic filtration device were evaluated, and regeneration of sulfided sorbents via injection into an oxidizing gas was studied. For both sorbent sulfidation and spent sorbent regeneration, gas-solid reaction occurred both in the duct and within layers of partially reacted sorbent captured by the ceramic filter. Very high sulfur removal efficiencies were obtained only in highly reducing hot gas compositions at or above about 700 C, using stoichiometric ratio (defined as ZnO/H[sub 2]S ratio) values of about 1.5, and sorbent particles of about 20[micro]m or less in diameter. Under such conditions, the experimental data indicated that reaction of H[sub 2]S with zinc vapor formed by reduction of zinc oxide contributed appreciably to sulfur removal. Negligible zinc loss from the hot zone of the reactor was detected, apparently due to rapid formation of zinc sulfide product layers on zinc oxide particles. The ceramic filtration devices captured 100% of all sorbent particles and were fully regenerable over periods of several tens of injection/backpulse cleaning cycles. Spent sorbent could be fully regenerated rapidly at 850 C without problems due to exotherm generation.
Download or read book Enhanced Durability of Desulfurization Sorbents for Fluidized bed Applications written by and published by . This book was released on 1991 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced integrated gasification combined cycle (IGCC) power systems require the development of high-temperature desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier down to very low levels. The objective of this investigation was to identify and demonstrate methods for enhancing the long-term chemical reactivity and mechanical strength of zinc ferrite, a leading regenerable sorbent, for fluidized-bed applications. Fluidized sorbent beds offer significant potential in IGCC systems because of their ability to control the highly exothermic regeneration involved. However, fluidized beds require a durable, attrition-resistant sorbent in the 100--300 [mu]m size range. A bench-scale high-temperature, high- pressure (HTHP) fluidized-bed reactor (7.6-cm I.D.) system capable of operating up to 24 atm and 800°C was designed, built and tested. A total of 175 sulfidation-regeneration cycles were carried out using KRW-type coal gas with various zinc ferrite formulations. A number of sorbent manufacturing techniques including spray drying, impregnation, crushing and screening, and granulation were investigated. While fluidizable sorbents prepared by crushing durable pellets and screening had acceptable sulfur capacity, they underwent excessive attrition during multicycle testing. The sorbent formulations prepared by a proprietary technique were found to have excellent attrition resistance and acceptable chemical reactivity during multicycle testing. However, zinc ferrite was found to be limited to 550°C, beyond which excessive sorbent weakening due to chemical transformations, e.g., iron oxide reduction, was observed.
Download or read book Durable Zinc Oxide Containing Sorbents for Moving Bed and Fluid Bed Applications written by Ranjani V. Siriwardane and published by . This book was released on 1998 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
