Abstract Booklet 2006 - Swanson School of Engineering - University ...

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23-2 Gas-Phase Incorporation of Palladium onto Ceria-doped Silica Aerogel for Water-Gas Shift Catalysis Gregory C. Turpin, Brian C. Dunn, Yifan Shi, Eric P. Fillerup, Ronald J. Pugmire, Edward M. Eyring, Richard D. Ernst, University of Utah, USA Prasanta Dutta, Mohindar Seehra, Vivek Singh, West Virginia University, USA The Water-Gas Shift (WGS) reaction is a means of producing hydrogen from coal-derived syngas. Palladium-promoted ceria has been investigated recently and has shown potential for low-temperature WGS catalysis. One limitation of traditional ceria is an inherent low surface area. While specialty cerias with surface areas as high as 300 m 2 /g have recently been prepared, they do not show structural stability at relevant temperatures. Supporting ceria on the surface of silica aerogel can take advantage of the very high surface area of the silica aerogel as well as the structural integrity of the support. Starting with a silica aerogel having an approximate surface area of 700 m 2 /g, ceria can be incorporated onto the surface with nominal loadings up to 40% (w/w), yielding final surface areas as high as 600 m 2 /g and generally above 450 m 2 /g. Palladium was added via the gas-phase incorporation (GPI) of a volatile organometallic complex, (η 3 -allyl)(η 5 -cyclopentadienyl)palladium, which is air-stable and prepared by a well-established procedure. Comparisons between GPI and conventional aqueous phase incorporation indicate increased activity for GPI-derived catalysts. For example, GPI can increase the WGS activity in excess of 150% for otherwise identical catalysts. This is presumably due to a higher dispersion of the Pd derived from GPI. A XRD analysis of catalysts derived from the GPI of Pd failed to show well-defined peaks indicative of agglomerated Pd particles, which agrees with the interpretation of high dispersion. 23-3 Mesoporous Metal-Promoted Ceria Catalysts for the Water Gas Shift Reaction Brian Dunn, Jennifer Gasser, Dae-Jung Kim, Eric Fillerup, Gary Hunyh, Gregory C. Turpin, Richard D. Ernest, Ronald J. Pugmire, Edward M. Eyring, Daniel W. Ramirez, University of Utah, USA Metal-promoted ceria catalysts that are active for the Water Gas Shift reaction have received considerable attention in recent years. One drawback to the ceria catalysts is the relatively low surface area achievable with traditional preparation methods. Two new types of ceria has been synthesized which possess high surface area and significant catalytic activity when palladium is incorporated into the catalyst. High surface area is attained by either preparing the ceria in an aerogel form or by combining the ceria with a mesostructured silica, SBA-15. The ceria aerogels have measured BET surface areas as high as ~300 m 2 /g which is about twice as large as the highest surface area ceria prepared via traditional methods. Measured BET surface areas of the ceria/SBA-15 composite material can be as high as 800 m 2 /g, however, the SBA-15 contributes substantially to this value. Various metals (Pd, Cu, Au) were incorporated into the ceria and the resulting catalysts were evaluated for Water Gas Shift activity in a 6-channel, laboratory-scale, packed bed reactor. The reactor was constructed with 6 parallel catalyst beds to allow for the simultaneous evaluation of up to 6 catalysts under identical reaction conditions (temperature, reactant flow, etc.). Each bed was equipped with an internal thermocouple to ensure accurate temperature measurement and to evaluate thermal cross-talk between reactors that could be caused by an exothermic reaction in the catalyst bed. No cross-talk was observed. The catalytic activity was measured at 5 temperatures between 150°C and 350°C for 24 hours at each temperature. At the highest temperature, the Pd/ceria aerogel catalyst converted 148 g CO / (hr g-Pd) resulting in the production of 11 g H 2 / (hr g-Pd). The Cu and Au catalysts were less active. The Pd-loaded ceria/SBA-15 based catalysts were less active than the Pd-loaded ceria aerogel based catalysts at temperatures less than 300°C, but become more active above 300°C. 23-4 Sulfur Deactivation Studies in the High-Temperature Water-Gas Shift Reaction over Chromium-Free Iron-Based Lingzhi Zhang, Umit Ozkan, The Ohio State University, USA Coal is the most abundant fossil fuel in our nation and how to make an efficient and environmentally acceptable use of coal has become a hot topic considering the increasing energy demands. Hydrogen production through integrated gasification combined-cycle (IGCC) has emerged as a highly promising technology. The commercialization of these joint power and hydrogen plants needs significant improvements in some of the steps following gasification to produce hydrogen more efficiently and economically. Among them is the water gas shift (WGS) reaction. Development of highly active, sulfur tolerant and chromium free catalysts will bring about the successful use of coal-derived gas for hydrogen production, resulting in enhanced use of our vast coal reserves. Sulfur deactivation studies have been carried on over current Fe-based catalysts prepared with different methods. A series of sulfur testing with simulated coal gas were run on the catalysts and different characterization techniques including BET, XRD, DRIFTS and XPS are used to describe catalyst properties before and after sulfur poisoning. Those characterizations also give us information about reaction mechanisms and help us explain functions of different promoters and their relation with reaction activities. 20 23-5 Hydrogen from Coal-Derived Methanol via an Autothermal Reformation Process Hyung Chul Yoon, Paul A. Erickson, University of California, Davis, USA This paper reports on an investigation of hydrogen production via reformation of coalbased methanol. We have proven that coal–derived liquids such as commercially available methanol can be converted into hydrogen using both steam and autothermal reforming methods. These studies have taken place at the Hydrogen Production & Utilization Laboratory at University of California Davis. Through chemical analysis, coal-based methanol has shown to have slightly higher amounts of trace hydrocarbons than chemical grade methanol derived from natural gas. While these trace hydrocarbons are typically inconsequential for some energy conversion devices, fuel cell applications require ultra pure hydrogen. Steam and autothermal reformers were investigated to find the optimal hydrogen production method in the existence of such trace impurities. Based on experimental results, steam-reforming of coal-based methanol has shown significant catalyst degradation caused by the trace impurities. Autothermal reformation of coal-derived methanol has demonstrated better performance with the trace impurities due to its higher operating temperature generated by the oxidation step. Autothermal reformation can also avoid some of the energy penalties of steam reformation but generally has a lower concentration of hydrogen due to the diluent nature of nitrogen by adding air as the oxidizer. This investigation shows that hydrogen production from coal-based methanol is possible using both reformation methods when considering fuel cell applications. SESSION 24 GLOBAL CLIMATE CHANGE: CO 2 CAPTURE – 1: CHEMICAL SORBENTS 24-1 Carbon Dioxide Removal from Flue Gas of Coal-Fired Power Plants Using Dry Regenerable Carbonate Sorbents in a Thermal-Swing Process Thomas Nelson, David Green, Paul Box, Raghubir Gupta, Andreas Weber, RTI International, USA The reversible reaction between sodium carbonate, carbon dioxide and water vapor, to form sodium bicarbonate (or an intermediate salt) can be used in a thermal swing cyclic process to recover concentrated carbon dioxide from power plant flue gas for sequestration or reuse. The process is initially targeted for coal-fired power plants incorporating wet flue gas desulfurization. The process is also suitable for natural gasfired power plants. Process modeling suggests that a process of this type offers a lower total energy requirement (and lower overall CO 2 capture costs) than existing liquid amine- based processes. Calcined sodium bicarbonate can be used as the sorbent for this process. Alternately, sodium carbonate incorporated in an attrition resistant support material can be used. The supported sorbent has demonstrated removal of >90% of the CO 2 present in a simulated flue gas in a bench-scale co-current down-flow reactor system. The partially reacted sorbent can be thermally regenerated, releasing CO 2 and H 2 O. Upon condensation of the H 2 O from the vent stream, a nearly pure CO 2 stream can be produced for reuse or sequestration. This paper discusses the results of a series of labscale down-flow reactor tests investigating the impact of gas composition, temperature, sorbent-to-gas ratio, and other important variables on the reaction of CO 2 with the sorbent. This paper also highlights results of field tests confirming that complete sorbent regeneration can be achieved in a heated screw conveyor, with minimal sorbent attrition. An integrated system incorporating a co-current down-flow absorber, a heated hollow screw conveyor/regenerator, and a hollow screw conveyor/sorbent cooler has been designed, constructed and tested 24-2 Developing a New Method for Direct Observation of the Effects of CO 2 Injection into Coal Seams Randal E. Winans, Sonke Seifert, Argonne National Laboratory, USA Tony Clemens, CRL Energy LTD, NEW ZEALAND Initial investigations to assess the suitability of in situ Small Angle X-Ray Scattering (SAXS) for directly observing changes in coal structure when injected with pressurized CO 2 were carried out at 50 bar pressure and ambient temperature on a suite of New Zealand coals and US coal samples from the Argonne Data Bank. The method requires the use of the Advanced Photon Source (APS) high energy synchrotron at Argonne. The high level of beam intensity provides the high levels of resolution and observational power required. These initial studies showed that: • High energy X-ray beams from the APS can be used to directly observe changes in coal structure as CO 2 is injected into the coal at high pressure. • The results are very reproducible • There are clear trends with coal rank. These initial successes suggest that it may be possible to develop a robust method for predicting CO 2 sequestration ability of coal seams based on direct observation.
24-3 Development of Fluidizable Lithium Silicate-Based Sorbents for High Temperature Carbon Dioxide Removal Weijiong Li, Santosh Gangwal, Raghubir Gupta, Brian S. Turk, RTI International, USA One of the key features accelerating the commercial deployment of integrated gasification combined cycle (IGCC) systems for producing electricity is that the addition of CO 2 capture and sequestration processes results in the lowest increment in capital and operating costs of any of the competing technologies. However, the commercially available technologies require significant cooling of the syngas to effectively capture the CO 2 that introduces a significant thermodynamic penalty for CO 2 capture. RTI International (RTI) has been working with regenerable sorbent materials for CO 2 capture at elevated temperatures with the potential to produce a high pressure high purity CO 2 product. This process offers the potential to significantly reduce any thermodynamic penalty associated with the CO 2 capture process. During the course of this research, RTI has developed Li 2 SiO 4 -based sorbents that have demonstrated CO 2 capture and regeneration in bench-scale testing. Results from this testing program were presented at last year’s Pittsburgh Coal Conference. Over the last year, RTI has built upon this success by conducting R&D for a fluidized Li 4 SiO 4 -based sorbent. The incentive for this work is the knowledge that a transport reactor system can be designed to treat high gas throughputs at relatively low capital costs, which will be required to treat the large CO 2 content of syngas derived from carbonaceous fuels, especially coal. A CO 2 capture technology that offers lower capital cost and higher thermal efficiency becomes more commercially attractive with the potential reward of earlier implementation. The technical challenges for developing a fluidized Li 4 SiO 4 sorbent are to achieve a high CO 2 reactivity, acceptable hydrodynamic properties and suitable attrition resistance. This presentation will describe the progress made in this R&D program. 24-4 Carbon Dioxide Separation through Supported Ionic Liquids Membranes in Polymeric Matrixes Jeffery Ilconich, David Luebke, Christina Myers, Henry Pennline, DOE/NETL, USA As compared to other gas separation techniques, membranes have several advantages which can include low capital cost, relatively low energy usage and scalability. While it could be possible to synthesize the ideal polymer for membrane separation of carbon dioxide from fuel gas, it would be very intensive in terms of money and time. Supported liquid membranes allow the researcher to utilize the wealth of knowledge available on liquid properties. Ionic liquids, which can be useful in capturing CO 2 from fuel gas because they posses high CO 2 solubility in the ionic liquid relative to H 2 , are an excellent candidate for this type of membrane. Ionic liquids are not susceptible to evaporation due to their negligible vapor pressure and thus eliminate the main problem typically seen with supported liquid membranes. A study has been conducted evaluating the use of the ionic liquid 1-hexyl-3-methylimidazolium bis(trifuoromethylsulfonyl)imide in supported ionic liquid membranes for the capture of CO 2 from streams containing H 2 . In a joint project, the ionic liquid was synthesized and characterized at the University of Notre Dame, incorporated into a polymeric matrix, and tested at the National Energy Technology Laboratory. Initial results have been very promising with calculated CO 2 permeabilities as high as 950 barrers and significant improvements in CO 2 /H 2 selectivity over the unmodified polymer at 37°C along with promising results at elevated temperatures. In addition to performance, the study included examining the choice of polymeric supports on performance and membrane stability in more realistic operating conditions. Also included in this study was an evaluation of novel approaches to incorporate the ionic liquid into polymer matrices to optimize the performance and stability of the membranes. 24-5 A Parametric Study for Regenerative Ammonia-Based Scrubbing for the Capture of CO 2 Kevin Resnik, James T. Yeh, Henry W. Pennline, DOE/NETL, USA William Garber, Deborah C. Hreha, Parsons Project Services, Inc., USA A continuous gas and liquid flow, regenerative scrubbing process for CO 2 capture is currently being demonstrated at the bench-scale level. An aqueous ammonia-based solution captures CO 2 from simulated flue gas in an absorber and releases a nearly pure stream of CO 2 in the regenerator. After the regeneration, the solution of ammonium compounds is recycled to the absorber. The design of the continuous flow unit was based on earlier exploratory results from a semi-batch reactor, where a CO 2 and N 2 gas mixture flowed through a well-mixed batch of ammonia-based solution. Recently, a series of tests have been conducted on the continuous unit to observe the effect of various parameters on CO 2 removal efficiency and regenerator effectiveness within the flow system. The parameters that were studied include absorber temperature, regenerator temperature, initial NH 3 concentration, simulated flue gas flow rate, liquid solvent inventory in the flow system, and height of the packed-bed absorber. Results from this current testing campaign conducted in the continuous scrubbing unit as well as test results from a 5-cycle semi-batch reactor will be discussed. 25-1 SESSION 25 GASIFICATION TECHNOLOGIES: ADVANCED SYNTHESIS GAS CLEANUP – 2 Synthesis and Reactivity Test of Nanostructure ZnO for Hot Gas Cleanup on the IGFC Si Ok Ryu, No-Kuk Park, You Jin Lee, Gi Bo Han, Tae Jin Lee, Yeungnam University, SOUTH KOREA Chih Hung Chang, Oregon State University, USA A nano-size zinc oxide was formulated for the effective removal of a very low concentration of sulfur compounds (H 2 S, COS) contained in a gasified fuel gas and their reactivity was also investigated in this study. They were prepared by a matrix-assisted method with various precursors. An active carbon was used for a matrix and zinc nitrate, zinc acetate, zinc chloride, and zinc sulfate were selected as precursors. Zinc nitrate was the best precursor for the formulation of the nano-size zinc oxide in the experiments. The size of the formulated nano-size zinc oxides was in the range of 20-30 nm and its surface area was about 56.2 m 2 /g. From TGA(thermal gravity analysis) test, it was found that its sulfur absorption rate was about 0.363 gS/min·100 g-sorbent. Their reactivity increased with the smaller size and the larger surface area of the sorbents. Most prepared nano-size zinc oxides showed an excellent performance for the removal of not only H 2 S but also COS. Their absorption rate was faster than commercial zinc oxides. In order to investigate the sulfur absorption characteristics of zinc oxide, a series of experiments for various nano-size zinc oxides formulated from different precursors were carried out in a packed-bed reactor system over the temperature 500°C. The sulfur capacity was about 5.83 gS/100 g-sorbent for H 2 S. It was concluded that the zinc oxide prepared by zinc nitrate as a precursor showed the highest sulfur removing capacity. 25-2 Desulfurization of High-Pressure Gasified Coal Using the UC Sulfur Recovery Process Diana Matonis, Howard S. Meyer, Dennis Leppin, Gas Technology Institute, USA The University of California Sulfur Recovery Process – High Pressure (UCSRP-HP) provides the potential to treat high-pressure, warm synthesis gas for the removal of ammonia, hydrogen chloride, and heavy metals including arsenic, mercury, cadmium, and selenium as well as essentially all of the hydrogen sulfide and carbonyl sulfide in a coalderived synthesis gas in a compound contacting tower. In the bottom or scrub section of the tower, the sour gas feed is contacted with a solvent that will absorb some steady state levels of water, ammonia, and hydrogen sulfide from the gas stream. As a result, the HCl content of the feed gas will be absorbed very effectively to form highly soluble NH 4 Cl. A small but significant concentration of NH 4 HS will also be present in the liquid phase, and the heavy metals As, Cd and Hg, will be absorbed to form their respective, very insoluble sulfides. Selenium, present in the syngas as H 2 Se, will be absorbed to form highly soluble (NH 4 ) 2 Se. The solvent is recirculated with a small slipstream being withdrawn, perhaps intermittently, for filtration and other treatment to remove the accumulated impurities and then returned. The gas stream leaving the scrub section passes into the reactor section through a chimney that effectively prevents the mixing of the solvent in the two sections. In the upper or reactor section of the tower, the UCSRP-HP uses a solvent with high capacity for H 2 S and SO 2 that also catalyzes the liquid-phase reaction of H 2 S and SO 2 to sulfur and water. Operation is above the melting point of sulfur, so the sulfur forms a separate liquid phase and is removed by simple decantation. The now scrubbed, sour gas, mixed with 10% − 20% excess SO 2 , is contacted at high pressure (the higher the better) with the UCSRP solvent at about 260 − 285°F (125 – 140°C). Substantially all of the H 2 S reacts to form liquid sulfur, leaving the excess SO 2 in the treated gas. The unreacted SO 2 is recovered in a separate absorber/stripper system, which may optionally also serve to dry the treated gas. The sulfur-free gas may optionally also be passed through a second absorber/stripper system for CO 2 recovery. The recovered SO 2 is combined with SO 2 produced by burning one-third of the liquid sulfur in a furnace, compressed and perhaps liquefied, and fed to the reactor column. The furnace employs either air or oxygen. All of the sulfur formed in the reactor is vaporized as it passes through the furnace; the unburned two-thirds condense in the waste-heat boiler. Any organic components dissolved in the sulfur will also be burned. The product sulfur has only a small amount of dissolved SO 2 as impurity. This paper will discuss the experimental and engineering studies of UCSRP-HP for syngas desulfurization with optional CO 2 recovery that include laboratory studies on vapor liquid equilibrium, solvent stability, corrosion and kinetic studies performed in laboratory scale equipment and column scale-up testing in bench-scale apparatus conducted at GTI and will highlight the potential economic benefits of the process. 25-3 Sorbents for Mercury Capture from Fuel Gas with Application to Gasification Systems Evan Granite, Henry W. Pennline, Christina R. Myers, Dennis C. Stanko, DOE/NETL, USA 21
Page 1 and 2: TABLE OF CONTENTS Oral Sessions Pag
Page 3 and 4: 1-1 SESSION 1 GASIFICATION TECHNOLO
Page 5 and 6: The U.S. pioneered development of s
Page 7 and 8: 5-5 Enhanced Hydrogen Production wi
Page 9 and 10: derived synthesis gases employing i
Page 11 and 12: Several physical adsorbents, partic
Page 13 and 14: 13-1 SESSION 13 GASIFICATION TECHNO
Page 15 and 16: promising Clean Coal technologies u
Page 17 and 18: high selectivity (theoretically pro
Page 19 and 20: 19-3 Development of Highly Efficien
Page 21: The Aim of the project is the impro
Page 25 and 26: the classical Lurgi-gasifcation pro
Page 27 and 28: 28-5 A Kinetic Approach to Catalyti
Page 29 and 30: turbine cycles. The models provide
Page 31 and 32: up to 290 psia and temperatures up
Page 33 and 34: 35-2 Development of Iron-Based Pero
Page 35 and 36: features of the BGL 1000 technology
Page 37 and 38: Heat-exchangers, particle filters,
Page 39 and 40: 41-4 Using Fly Ash-Based Foundry Co
Page 41 and 42: ocks using elemental ratios. Data f
Page 43 and 44: 600-900°C. Changes in the amount o
Page 45 and 46: ATL process has three stages, namel
Page 47 and 48: commercial-scale gasifier was shutd
Page 49 and 50: 52-5 Pilot-Scale Demonstration of U
Page 51 and 52: POSTER SESSION 1 COMBUSTION TECHNOL
Page 53 and 54: experimental data available in lite
Page 55 and 56: activation. It was concluded that C

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