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Effect of palladium dispersion on the capture of toxic components from fuel gas by palladium-alumina sorbents

Description: The dispersion and location of Pd in alumina-supported sorbents prepared by different methods was found to influence the performance of the sorbents in the removal of mercury, arsine, and hydrogen selenide from a simulated fuel gas. When Pd is well dispersed in the pores of the support, contact interaction with the support is maximized, Pd is less susceptible to poisoning by sulfur. and the sorbent has better long-term activity for adsorption of arsine and hydrogen selenide. but poorer adsorption capacity for Hg. As the contact interaction between Pd and the support is lessened the Pd becomes more susceptible to poisoning by sulfur. resulting in higher capacity for Hg, but poorer long-term performance for adsorption of arsenic and selenium.
Date: January 1, 2011
Creator: Baltrus, J.P.; Granite, E.J.; Rupp, E.C.; Stanko, D.C.; Howard, B. & Pennline, H.W.
Partner: UNT Libraries Government Documents Department

Surface characterization of Pd/Al2O3 sorbents for mercury capture from fuel gas

Description: The surface composition of a series of Pd/alumina sorbents has been characterized to better understand the factors influencing their ability to adsorb mercury from fuel gas. Both a temperature effect and a dispersion effect were found. Maximum adsorption of Hg occurred at the -lowest temperature tested, 204°C, and decreased with increasing temperatures. Maximum adsorption of Hg on a per-atom basis of Pd is observed at low loadings of Pd ( < 8.5% Pd) due to better dispersion of Pd at those loadings; a change in its partitioning occurs at higher loadings. The presence of H2S 'in the fuel gas acts to promote the adsorption of Hg through its association with Hg in the Pd lattice.
Date: January 1, 2008
Creator: Baltrus, J.P.; Granite, E.J.; Stanko, D.C. & Pennline, H.W.
Partner: UNT Libraries Government Documents Department

Experience with atmospheric fluidized bed gasification of switchgrass

Description: Switchgrass was gasified in a bubbling fluidized bed reactor rated at 800 kW (2.75 MMBtu/hr) thermal input and operating at atmospheric pressure. A combustible gas with higher heating value varying between 4.2--5.9 MJ/Nm{sup 3} (114--160 Btu/scf) was produced. Carbon conversion was approximately 85%. Difficulties in feeding high moisture switchgrass inhibited smooth reactor operation. Several feed systems for switchgrass were tried with varying degrees of success. The results of gasification trials using switchgrass as fuel are described.
Date: December 31, 1998
Creator: Smeenk, J. & Brown, R.C.
Partner: UNT Libraries Government Documents Department

The TEES process cleans waste and produces energy

Description: A gasification system is under development that can be used with most types of wet organic wastes. The system operates at 350{degrees}C and 205 atm using a liquid water phase as the processing medium. Since a pressurized system is used, the wet waste can be fed as a solution or slurry to the reactor without drying. Through the development of catalysts, a useful processing system has been produced. The system has utility both for direct conversion of high-moisture biomass to fuel gas or as a wastewater cleanup system for wet organic wastes including unconverted biomass from bioconversion processes. By the use of this system >99% conversions of organic waste to medium-Btu fuel gas can be achieved.
Date: February 1, 1995
Creator: Elliott, D.C. & Silva, L.J.
Partner: UNT Libraries Government Documents Department

Multi-stage fuel cell system method and apparatus

Description: A high efficiency, multi-stage fuel cell system method and apparatus is provided. The fuel cell system is comprised of multiple fuel cell stages, whereby the temperatures of the fuel and oxidant gas streams and the percentage of fuel consumed in each stage are controlled to optimize fuel cell system efficiency. The stages are connected in a serial, flow-through arrangement such that the oxidant gas and fuel gas flowing through an upstream stage is conducted directly into the next adjacent downstream stage. The fuel cell stages are further arranged such that unspent fuel and oxidant laden gases too hot to continue within an upstream stage because of material constraints are conducted into a subsequent downstream stage which comprises a similar cell configuration, however, which is constructed from materials having a higher heat tolerance and designed to meet higher thermal demands. In addition, fuel is underutilized in each stage, resulting in a higher overall fuel cell system efficiency.
Date: December 1, 1997
Creator: George, Thomas J. & Smith, William C.
Partner: UNT Libraries Government Documents Department

SECOND GENERATION PFBC SYSTEMS R AND D - PHASE 2 AND 3

Description: When DOE funds were exhausted in March 1995, all Phase 2 activities were placed on hold. In February 1996 a detailed cost estimate was submitted to the DOE for completing the two remaining Phase 2 Multi Annular Swirl Burner (MASB) topping combustor test campaigns; in August 1996 release was received from FETC to proceed with the two campaigns to: (1) test the MASB at proposed demonstration plant full to minimum load operating conditions; (2) identify the lower oxygen limit of the MASB; (3) demonstrate natural gas to carbonizer fuel gas switching; and (4) demonstrate operation with ''low temperature'' compressor discharge air rather than high temperature ({approx}1600 F) vitiated air.
Date: August 5, 1999
Creator: Robertson, A.
Partner: UNT Libraries Government Documents Department

DEVELOPMENT AND EVALUATION OF NANOSCALE SORBENTS FOR MERCURY CAPTURE FROM WARM FUEL GAS

Description: The Mercury Testing Experimental System available in GTI's Hot Gas Cleanup laboratory was prepared for the project. As part of the shakedown testing, the system was checked for possible gas leaks and fixed. In addition, the mass flow controller was calibrated for diluent N{sub 2} stream. A major part of the shakedown testing was the calibration of the semi-continuous mercury analyzer and the verification of the permeation rate of the mercury permeation tube. It was found that the analyzer's mercury concentration measurements were much lower than expected from the permeation tube rate calculations. Vendors of the analyzer and the permeation tube are contacted to find out the reason for this discrepancy.
Date: January 1, 2005
Creator: Jadhav, Raja A. & Meyer, Howard
Partner: UNT Libraries Government Documents Department

Two-stage fixed-bed gasifier with selectable middle gas off-take point

Description: A two-stage fixed bed coal gasifier wherein an annular region is in registry with a gasification zone underlying a devolatilization zone for extracting a side stream of high temperature substantially tar-free gas from the gasifier. A vertically displaceable skirt means is positioned within the gasifier to define the lower portion of the annular region so that vertical displacement of the skirt means positions the inlet into the annular region in a selected location within or in close proximity to the gasification zone for providing a positive control over the composition of the side stream gas.
Date: December 31, 1991
Creator: Strickland, L. D. & Bissett, L. A.
Partner: UNT Libraries Government Documents Department

ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

Description: Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine and hydrogen ...
Date: July 31, 2010
Creator: Musich, Mark A.; Swanson, Michael L.; Dunham, Grant E. & Stanislowski, Joshua J.
Partner: UNT Libraries Government Documents Department

Synthesis and Characterization of CO- and H2S-Tolerant Electrocatalysts for PEM Fuel Cell

Description: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H{sub 2}S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. In this work binary, ternary, and quaternary platinum-based electrocatalysts were synthesized for the purpose of lowering the cost and increasing the CO tolerance of the membrane electrode assembly (MEA) in the fuel cell. The metals Ru, Mo, W, Ir, Co and Se were alloyed with platinum on a carbon support using a modified reduction method. These catalysts were fabricated into MEAs and evaluated for electrical performance and CO tolerance with polarization experiments. The quaternary system Pt/Ru/Mo/Ir system is the most CO tolerant in the PEMFC and has a low total metal loading of 0.4 mg/cm{sup 2} in the electrode of the cell.
Date: September 30, 2006
Creator: Ilias, Shamsuddin
Partner: UNT Libraries Government Documents Department

Method for high temperature mercury capture from gas streams

Description: A process to facilitate mercury extraction from high temperature flue/fuel gas via the use of metal sorbents which capture mercury at ambient and high temperatures. The spent sorbents can be regenerated after exposure to mercury. The metal sorbents can be used as pure metals (or combinations of metals) or dispersed on an inert support to increase surface area per gram of metal sorbent. Iridium and ruthenium are effective for mercury removal from flue and smelter gases. Palladium and platinum are effective for mercury removal from fuel gas (syngas). An iridium-platinum alloy is suitable for metal capture in many industrial effluent gas streams including highly corrosive gas streams.
Date: April 25, 2006
Creator: Granite, E. J. & Pennline, H. W.
Partner: UNT Libraries Government Documents Department

Subtask 2.8 - Control of Trace Elements in Gasification Systems

Description: Detailed investigations were carried out to investigate the removal of mercury using a variety of substrates at elevated temperature under reducing conditions. Sorbents tested mainly comprised 6A, 7A, 1B, 2B, and metals from the periodic table. The new high-surface halogen-treated carbon sorbents performed exceptionally well on the bench scale at relatively high temperatures (400 C). The new sorbents could be incorporated into a gas cleanup technology for fuel gas, where the gas is cooled to medium temperatures. Other work in this task focused on halogen-containing sorbents prepared on a carbon support. Similar sorbents had been previously found to be superior for mercury in flue gas. All granular sorbents were conducted in fixed beds heated at 350 and 400 C with 10 vol% hydrogen in a nitrogen stream containing 34.8 {mu}g/m{sup 3} of Hg{sup 0}.
Date: March 28, 2009
Creator: Swanson, Michael
Partner: UNT Libraries Government Documents Department

Development and Evaluation of Nanoscale Sorbents for Mercury Capture from Warm Fuel Gas

Description: Several different types of nanocrystalline metal oxide sorbents were synthesized and evaluated for capture of mercury (Hg) from coal-gasifier warm fuel gas. Detailed experimental studies were carried out to understand the fundamental mechanism of interaction between mercury and nanocrystalline sorbents over a range of fuel gas conditions. The metal oxide sorbents evaluated in this work included those prepared by GTI's subcontractor NanoScale Materials, Inc. (NanoScale) as well as those prepared in-house. These sorbents were evaluated for mercury capture in GTI's Mercury Sorbent Testing System. Initial experiments were focused on sorbent evaluation for mercury capture in N{sub 2} stream over the temperature range 423-533 K. These exploratory studies demonstrated that NanoActive Cr{sub 2}O{sub 3} along with its supported form was the most active of the sorbent evaluated. The capture of Hg decreased with temperature, which suggested that physical adsorption was the dominant mechanism of Hg capture. Desorption studies on spent sorbents indicated that a major portion of Hg was attached to the sorbent by strong bonds, which suggested that Hg was oxidized by the O atoms of the metal oxides, thus forming a strong Hg-O bond with the oxide. Initial screening studies also indicated that sulfided form of CuO/alumina was the most active for Hg capture, therefore was selected for detailed evaluation in simulated fuel gas (SFG). It was found that such supported CuO sorbents had high Hg-sorption capacity in the presence of H{sub 2}, provided the gas also contained H{sub 2}S. Exposure of supported CuO sorbent to H{sub 2}S results in the formation of CuS, which is an active sorbent for Hg capture. Sulfur atom in CuS forms a bond with Hg that results into its capture. Although thermodynamically CuS is predicted to form unreactive Cu{sub 2}S form when exposed to H{sub 2}, it is hypothesized that Cu atoms in ...
Date: May 31, 2006
Creator: Jadhav, Raja A.
Partner: UNT Libraries Government Documents Department

A Feasibility Study for Recycling Used Automotive Oil Filters In A Blast Furnace

Description: This feasibility study has indicated that of the approximately 120,000 tons of steel available to be recycled from used oil filters (UOF's), a maximum blast furnace charge of 2% of the burden may be anticipated for short term use of a few months. The oil contained in the most readily processed UOF's being properly hot drained and crushed is approximately 12% to 14% by weight. This oil will be pyrolized at a rate of 98% resulting in additional fuel gas of 68% and a condensable hydrocarbon fraction of 30%, with the remaining 2% resulting as carbon being added into the burden. Based upon the writer's collected information and assessment, there appears to be no operational problems relating to the recycling of UOF's to the blast furnace. One steel plant in the US has been routinely charging UOF's at about 100 tons to 200 tons per month for many years. Extensive analysis and calculations appear to indicate no toxic consideration as a result of the pyrolysis of the small contained oil ( in the 'prepared' UOFs) within the blast furnace. However, a hydrocarbon condensate in the ''gasoline'' fraction will condense in the blast furnace scrubber water and may require additional processing the water treatment system to remove benzene and toluene from the condensate. Used oil filters represent an additional source of high quality iron units that may be effectively added to the charge of a blast furnace for beneficial value to the operator and to the removal of this resource from landfills.
Date: January 21, 2002
Creator: Smailer, Ralph M.; Dressel, Gregory L. & Hill, Jennifer Hsu
Partner: UNT Libraries Government Documents Department

Conversion of high carbon refinery by-products. Quarterly report, July 1--September 30, 1996

Description: The overall objective of the project is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, byproducts, and other low value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed to pyrolysis and steam gasification in a circulating bed of solids. Carbon residue formed during pyrolysis, as well as metals in the feed, are captured by the circulating solids which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the gasification process. Tests were conducted in the Transport Reactor Test Unit (TRTU) to study gasification and combustion of Rose Bottoms solids using the spent FCC (Fluid Catalytic Cracker) catalyst as the circulating medium and petroleum coke at temperature of 1,750 F. The Rose (Residuum Oil Supercritical Extraction) bottoms was produced in the Kellogg`s Rose unit. A dry solid feed system developed previously was used to feed petroleum coke and Rose Bottoms. Studies were also done in the Bench Scale Reactor Unit (BRU) to investigate partial oxidation and gasification of petroleum coke over temperature range of 1,800 F to 2,100 F. Results obtained in the BRU and TRTU on petroleum coke formed the basis to develop a flowsheet to process this material in a transport reactor. Results from these studies are presented in this report.
Date: October 18, 1996
Creator: Katta, S.; Henningsen, G.; Lin, Y.Y. & Agrawal, R.
Partner: UNT Libraries Government Documents Department

Indirectly heated fluidized bed biomass gasification using a latent heat ballast

Description: The objective of this study is to improve the heating value of gas produced during gasification of biomass fuels using an indirectly heated gasifier based on latent heat ballasting. The latent heat ballast consists of lithium fluoride salt encased in tubes suspended in the reactor. The lithium fluoride has a melting point that is near the desired gasification temperature. With the ballast a single reactor operating in a cyclic mode stores energy during a combustion phase and releases it during a pyrolysis phase. Tests were carried out in a fluidized bed reactor to evaluate the concept. The time to cool the reactor during the pyrolysis phase from 1,172 K (1,650 F) to 922 K (1,200 F) increased 102% by use of the ballast system. This extended pyrolysis time allowed 33% more biomass to be gasified during a cycle. Additionally, the total fuel fraction pyrolyzed to produce useful gas increased from 74--80%. Higher heating values of 14.2 to 16.6 MJ/Nm{sup 3} (382--445 Btu/scf) on a dry basis were obtained from the ballasted gasifier.
Date: December 31, 1998
Creator: Pletka, R.; Brown, R. & Smeenk, J.
Partner: UNT Libraries Government Documents Department

Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, October--December 1994

Description: The goal is the development of simpler and economically superior processing of regenerable sorbents used for control of hydrogen sulfide in hot, high-pressure gas streams in advanced power generating systems. The improved processing will produce an elemental sulfur byproduct. Progress during the past quarter was limited by delays in identifying an appropriate analytical instrument for measuring the concentration of sulfur species (S{sub x}(g), H{sub 2}S, and SO{sub 2} in the regeneration product gas. The ability to carry out this analysis on a real-time basis is an important component of the overall project and we feel that a satisfactory gas analysis procedure should be available before forging ahead with other experimental activities. The primary accomplishment, therefore, was the completion and submission of the Task 3 Project Plan. This plan, which assumed a satisfactory solution to sulfur analysis problem, is included in this quarterly report.
Date: January 1, 1995
Creator: Harrison, D.P.
Partner: UNT Libraries Government Documents Department

Particulate hot gas stream cleanup technical issues. Quarterly report, January 1--March 31, 1998

Description: The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task 1 research activities during the past quarter included characterizations of samples collected during a site visit on January 20 to the Department of Energy/Southern Company Services Power Systems Development Facility (PSDF). Comparisons were made between laboratory analyses of these PSDF ashes and field data obtained from facility operation. In addition, selected laboratory techniques were reviewed to assess their reproducibility and the influence of non-ideal effects and differences between laboratory and filter conditions on the quantities measured. Further work on the HGCU data base is planned for the next quarter. Two Dupont PRD-66 candle filters, one McDermott candle filter, one Blasch candle filter, and one Specific Surfaces candle filter were received at SRI for testing. A test plan and cutting plan for these candles was developed. Acquisition of two of the Dupont PRD-66 candle filters will allow candle-to-candle variability to be examined.
Date: August 1, 1998
Partner: UNT Libraries Government Documents Department

Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

Description: Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixtures derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.
Date: December 31, 1996
Creator: Poston, J.A.
Partner: UNT Libraries Government Documents Department

Development of proton-conducting membranes for hydrogen separation

Description: The objective of this project is to develop dense ceramic membranes that can efficiently and economically separate hydrogen from gaseous mixtures (e.g., syngas, coal gas, etc.). Toward this end, materials with suitable electronic and protonic conductivities will be identified, and methods for fabricating thin, dense ceramic membranes from such materials will be developed. The chemical and mechanical stability of the membranes will be determined to estimate the expected lifetime of the membranes. Scoping-level evaluations will be performed to identify potential applications of proton membrane technology. Areas that will be evaluated include overall market scale, typical site operating scale, process integration opportunities and issues, and alternative-source economics. The literature on mixed electronic/protonic conductors was surveyed to identify suitable candidate materials. SrCe{sub 1{minus}x}M{sub x}O{sub 3{minus}{delta}} and BaCe{sub 1{minus}x}M{sub x}O{sub 3{minus}{delta}} (where M is a fixed-valent dopant such as Ca, Y, Yb, In, Nd, or Gd) were selected for further investigation on the basis of their reported total conductivities and proton transference numbers.
Date: July 1, 1998
Creator: Balachandran, U.; Guan, J. & Dorris, S.E.
Partner: UNT Libraries Government Documents Department

Task 6.5 -- Gas separation and hot-gas cleanup. Semi-annual report, January 1--June 30, 1995

Description: The objective of this task is to develop and test superior gas separation membranes. Several methods will be tested to prepare new membrane materials, including physical vapor deposition via electron beam evaporation. Other ceramic filter materials used in hot-gas particulate filters will be obtained from selected suppliers for use as substrates to develop a thin-film membrane selective to hydrogen permeation. This thin-film membrane will be modified via an EERC proprietary process. The base filter materials will already have been characterized for hydrothermal and chemical stability and pore size. The selectivity of these membrane materials for separating undesired gases will be determined. Selectivity will be measured by mixing bottled gases in a manifold, feeding the gases to the membrane, and sampling the inlet, permeate, and raffinate streams for gas composition and volumetric flow rate. Specific questions to be answered include the following: What are the effects of ceramic membrane properties (i.e., surface area, pore size, and coating thickness) on permeability and selectivity of the desired gases? What are the effects of operating conditions (i.e., temperature, pressure, and flow rate) on permeability and selectivity?
Date: December 31, 1995
Creator: Swanson, M.L.; Bieber, J.A.; Ness, R.O. Jr. & Hurley, J.P.
Partner: UNT Libraries Government Documents Department