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Evaluation of fine-particle size catalysts using bituminous and subbituminous coals

Description: The objectives of Sandia`s fine-particle size catalyst testing project are to evaluate and compare the activities of fine-particle size catalysts being developed in DOE/PETC`s Advanced Research Coal Liquefaction Program by using Sandia`s standard coal liquefaction test procedures. The first test procedure uses bituminous coal (DECS-17 Blind Canyon coal), phenanthrene as the reaction solvent, and a factorial experimental design that is used to evaluate catalysts over ranges of temperature, time, and catalyst loading. The best catalyst evaluated to date is West Virginia University`s iron catalyst that was impregnated onto the coal. Current work is aimed at developing a standard test procedure using subbituminous Wyodak coal. Ibis test is being developed using Pacific Northwest Laboratories` 6-line ferrihydrite catalyst and coal samples impregnated with either molybdenum or iron at Argonne National Laboratories. Results of testing catalysts with bituminous coal will be summarized and the development of the subbituminous coal test procedure will be presented.
Date: June 1, 1996
Creator: Stohl, F.V.; Diegert, K.V. & Goodnow, D.C.
Partner: UNT Libraries Government Documents Department

Experiments and computational modeling of pulverized-coal ignition. Semiannual report, Apr 1, 1998--Sep 30, 1998

Description: Under typical conditions of pulverized-coal combustion, which is characterized by fine particles heated at very high rates, there is currently a lack of certainty regarding the ignition mechanism of bituminous and lower rank coals. It is unclear whether ignition occurs first at the particle-oxygen interface (heterogeneous ignition) or if it occurs in the gas phase due to ignition of the devolatilization products (homogeneous ignition). Furthermore, there have been no previous studies aimed at determining the dependence of the ignition mechanism on variations in experimental conditions, such as particle size, oxygen concentration, and heating rate. Finally, there is a need to improve current mathematical models of ignition to realistically and accurately depict the particle-to-particle variations that exist within a coal sample. Such a model is needed to extract useful reaction parameters from ignition studies, and to interpret ignition data in a more meaningful way. The authors propose to examine fundamental aspects of coal ignition through (1) experiments to determine the ignition mechanism of various coals by direct observation, and (2) modeling of the ignition process to derive rate constants and to provide a more insightful interpretation of data from ignition experiments. They propose to use a novel laser-based ignition experiment to achieve their objectives. The heating source will be a pulsed, carbon dioxide laser in which both the pulse energy and pulse duration are independently variable, allowing for a wide range of heating rates and particle temperatures--both of which are decoupled from each other and from the particle size. This level of control over the experimental conditions is truly novel in ignition and combustion experiments. Laser-ignition experiments also offer the distinct advantage of easy optical access to the particles because of the absence of a furnace or radiating walls, and thus permit direct observation and particle temperature measurement. The ignition mechanism ...
Date: October 31, 1998
Creator: Chen, John C. & Owusu-Ofori, Samuel
Partner: UNT Libraries Government Documents Department


Description: This is the first Annual Technical Report of activities under DOE Contract No. DE-AC22-94PC93054. Activities from the first three quarters of the fiscal 1998 year were reported previously as Quarterly Technical Progress Reports (DOE/PC93054-57, DOE/PC93054-61, and DOE/PC93054-66). Activities for the period July 1 through September 30, 1998, are reported here. This report describes CONSOL's characterization of process-derived samples obtained from HTI Run PB-08. These samples were derived from operations with Black Thunder Mine Wyoming subbituminous coal, simulated mixed waste plastics, and pyrolysis oils derived from waste plastics and waste tires. Comparison of characteristics among the PB-08 samples was made to ascertain the effects of feed composition changes. A comparison also was made to samples from a previous test (Run PB-06) made in the same processing unit, with Black Thunder Mine coal, and in one run condition with co-fed mixed plastics.
Date: May 1, 1999
Creator: Robbins, G.A.; Winschel, R.A. & Brandes, S.D.
Partner: UNT Libraries Government Documents Department

JV 58-Effects of Biomass Combustion on SCR Catalyst

Description: A portable slipstream selective catalytic reduction (SCR) reactor was installed at a biomass cofired utility boiler to examine the rates and mechanisms of catalyst deactivation when exposed to biomass combustion products. The catalyst was found to deactivate at a much faster rate than typically found in a coal-fired boiler, although this may have been the result of high ash loading rather than a general property of biomass combustion. Deactivation was mainly the result of alkali and alkaline-earth sulfate formation and growth in catalyst pores, apparently caused by alkaline-earth ash deposition on or near the pore sites. The high proportion of biomass in the fuel contributed to elevated levels of alkali and alkaline-earth material in the ash when compared to coal ash, and these higher levels provided more opportunity for sulfate formation. Based on laboratory tests, neither catalyst material nor ammonia contributed measurably to ash mass gains via sulfation. A model constructed using both field and laboratory data was able to predict catalyst deactivation of catalysts under subbituminous coal firing but performed poorly at predicting catalyst deactivation under cofiring conditions. Because of the typically higher-than coal levels of alkali and alkaline-earth elements present in biomass fuels that are available for sulfation at typical SCR temperatures, the use of SCR technology and biomass cofiring needs to be carefully evaluated prior to implementation.
Date: August 31, 2006
Creator: Folkedahl, Bruce C.; Zygarlicke, Christopher J.; Strege, Joshua R.; McCollor, Donald P.; Laumb, Jason D. & Kong, Lingbu
Partner: UNT Libraries Government Documents Department

Utilization of Partially Gasified Coal for Mercury Removal

Description: In this project, General Electric Energy and Environmental Research Corporation (EER) developed a novel mercury (Hg) control technology in which the sorbent for gas-phase Hg removal is produced from coal in a gasification process in-situ at a coal burning plant. The main objective of this project was to obtain technical information necessary for moving the technology from pilot-scale testing to a full-scale demonstration. A pilot-scale gasifier was used to generate sorbents from both bituminous and subbituminous coals. Once the conditions for optimizing sorbent surface area were identified, sorbents with the highest surface area were tested in a pilot-scale combustion tunnel for their effectiveness in removing Hg from coal-based flue gas. It was determined that the highest surface area sorbents generated from the gasifier process ({approx}600 m{sup 2}/g) had about 70%-85% of the reactivity of activated carbon at the same injection rate (lb/ACF), but were effective in removing 70% mercury at injection rates about 50% higher than that of commercially available activated carbon. In addition, mercury removal rates of up to 95% were demonstrated at higher sorbent injection rates. Overall, the results of the pilot-scale tests achieved the program goals, which were to achieve at least 70% Hg removal from baseline emissions levels at 25% or less of the cost of activated carbon injection.
Date: September 9, 2008
Creator: Samuelson, Chris; Maly, Peter & Moyeda, David
Partner: UNT Libraries Government Documents Department

Short contact time direct coal liquefaction using a novel batch reactor. Quarterly report, 1996

Description: The objective of this research is to optimize the design and operation of the bench scale batch reactor (SCTBR) for coal liquefaction at short contact times (0.01 to 10 minutes or longer). Additional objectives are to study the kinetics of direct coal liquefaction particularly at short reaction times, and to investigate the role of the organic oxygen components of coal and their reaction pathways during liquefaction. Many of those objectives have already been achieved and others are still in progress. This quarterly report covers further progress toward those objectives. Much of the previous quarterly report was concerned mainly in the retrograde reactions occurring during the liquefaction process. This report is largely devoted to the kinetics and mechanisms of the liquefaction process itself and the influence of the liquefaction solvents.
Date: May 1, 1996
Creator: Klein, M.T.; Calkins, W.H. & Huang, H.
Partner: UNT Libraries Government Documents Department

Influence of binary swelling solvents: Mechanism of action

Description: This study addresses the dramatic up-take of a poor swelling solvent in Argonne Premium Coal Samples (APCS), Illinois No. 6, Beulah-Zap and Lewiston-Stockton when such a solvent is spiked with various amounts of the strong swelling solvent, pyridine. The unexpected up-take can be explained in terms of four different processes: (1) disruption of weak hydrogen bonds which isolate the interconnected micropore system; (2) disruption of weak hydrogen bonds which protect individual micropores; (3) competition of pyridine for the active sites involved in the hydrogen bonds or the {open_quotes}poisoning{close_quotes} of active sites; and (4) disruption of stronger hydrogen bonds within the macromolecules which causes an opening of the structure. When more than 5% pyridine is used, no additional disruption of the hydrogen-bonded network occurs. The structural changes were monitored by spin probe incorporation which was measured by EPR spectroscopy.
Date: December 31, 1995
Creator: Ding, R.; Tucker, D. & Kispert, L.D.
Partner: UNT Libraries Government Documents Department

Evaluation of fine-particle size catalysts using standard test procedures

Description: The goal of this project is to evaluate and compare the activities/selectivities of fine-particle size catalysts being developed in the DOE/PETC Advanced Research (AR) Liquefaction Program by using standard coal liquefaction activity test procedures. Since bituminous and subbituminous coals have significantly different properties, it is feasible that catalysts may perform differently with these coal types. Because all previous testing has been done with the DECS-17 Blind Canyon bituminous coal, it is important to develop the capability of evaluating catalysts using a subbituminous coal. Initial efforts towards developing a subbituminous coal test are aimed at comparing the reactivities of the Wyodak subbituminous coal and the Blind Canyon bituminous coal. Therefore, the same factorial experimental design was used with the Wyodak coal as was used previously with the Blind Canyon coal. In addition, PNL`s 6-line ferrihydrite catalyst precursor was used in the development of the Wyodak coal test procedure because this catalyst is the best powder catalyst found to date in Sandia`s tests with Blind Canyon coal. Results show that Blind Canyon coal yields higher DHP amounts in the reaction products and higher tetrahydrofuran conversions at the higher severity conditions. Wyodak coal gives higher heptane conversions and higher gas yields for all conditions tested.
Date: July 1, 1996
Creator: Stohl, F.V.; Diegert, K.V. & Goodnow, D.C.
Partner: UNT Libraries Government Documents Department

Linkages between aromatic structures in the Argonne Premium Coal Samples

Description: The objective of this study is to elucidate the nature of the important linkages between aromatic clusters and variations of these links with coal rank. From studies using methods such as NMR and mass spectrometry, the authors have considerable information on the size and types of aromatic clusters in the Argonne coals. In this study, extracts, model polymers, extracted coals, and modified coals are examined by temperature resolved high resolution mass spectrometry. There is evidence that strong bond cleavage may be very important for volatile release in pyrolysis of higher rank coals.
Date: April 1, 1997
Creator: Winans, R.E. & Tomczyk, N.A.
Partner: UNT Libraries Government Documents Department

Upgrading low rank coal using the Koppelman Series C process

Description: Development of the K-Fuel technology began after the energy shortage of the early 1970s in the United States led energy producers to develop the huge deposits of low-sulfur coal in the Powder River Basin (PRB) of Wyoming. PRB coal is a subbituminous C coal containing about 30 wt % moisture and having heating values of about 18.6 megajoules/kg (8150 Btu/lb). PRB coal contains from 0.3 to 0.5 wt % sulfur, which is nearly all combined with the organic matrix in the coal. It is in much demand for boiler fuel because of the low-sulfur content and the low price. However, the low-heating value limits the markets for PRB coal to boilers specially designed for the high- moisture coal. Thus, the advantages of the low-sulfur content are not available to many potential customers having boilers that were designed for bituminous coal. This year about 250 million tons of coal is shipped from the Powder River Basin of Wyoming. The high- moisture content and, consequently, the low-heating value of this coal causes the transportation and combustion of the coal to be inefficient. When the moisture is removed and the heating value increased the same bundle of energy can be shipped using one- third less train loads. Also, the dried product can be burned much more efficiently in boiler systems. This increase in efficiency reduces the carbon dioxide emissions caused by use of the low-heating value coal. Also, the processing used to remove water and restructure the coal removes sulfur, nitrogen, mercury, and chlorides from the coal. This precombustion cleaning is much less costly than stack scrubbing. PRB coal, and other low-rank coals, tend to be highly reactive when freshly mined. These reactive coals must be mixed regularly (every week or two) when fresh, but become somewhat more stable after they have aged ...
Date: January 1, 1998
Creator: Merriam, N.W., Western Research Institute
Partner: UNT Libraries Government Documents Department

FT-IR spectroscopic investigation of fireside deposits in a pilot-scale combustor. Topical report

Description: Successful operation of conventional as well as advanced coal combustion systems depends on controlling and minimizing the development of ash fouling and stagging, i.e., fireside deposits. The development of these deposits depends not only on combustion design and operating conditions, but also on the composition and quantity of the inorganic species in the coal. Coals contain several minerals, and low-rank coals contain organically associated cations that vary in their association, size, and position relative to one another and in their composition. In the course of combustion, the major inorganic constituents directly affect chemical and physical transformations, such that inorganic species are initially partitioned into gaseous, liquid, and solid intermediates. this report discusses the design and construction of an infrared emission sampling probe for ash deposits, and discusses the correlations of ash build-up with the emission spectra.
Date: December 1995
Partner: UNT Libraries Government Documents Department

Advanced liquefaction using coal swelling and catalyst dispersion techniques. Volume 2, appendices. Final technical report, October 1, 1991--September 30, 1994

Description: Liquefaction experiments were undertaken using subbituminous Black Thunder mine coal to observe the effects of aqueous SO{sub 2} coal beneficiation and the introduction of various coal swelling solvents and catalyst precursors. Aqueous SO{sub 2} beneficiation of Black Thunder coal removed alkali metals and alkaline earth metals, increased the sulfur content and increased the catalytic liquefaction conversion to THF solubles compared to untreated Black Thunder coal. The liquefaction solvent had varying effects on coal conversion, depending upon the type of solvent added. The hydrogen donor solvent, dihydroanthracene, was most effective, while a coal-derived Wilsonville solvent promoted more coal conversion than did relatively inert 1-methylnaphthalene. Swelling of coal with hydrogen bonding solvents tetrahydrofuran (THF), isopropanol, and methanol, prior to reaction resulted in increased noncatalytic conversion of both untreated and SO{sub 2} treated Black Thunder coals, while dimethylsulfoxide (DMSO), which was absorbed more into the coal than any other swelling solvent, was detrimental to coal conversion. Swelling of SO{sub 2} treated coal before liquefaction resulted in the highest coal conversions; however, the untreated coal showed the most improvements in catalytic reactions when swelled in either THF, isopropanol, or methanol prior to liquefaction. The aprotic solvent DMSO was detrimental to coal conversion.
Date: April 1, 1995
Creator: Curtis, C.W.; Chander, S. & Gutterman, C.
Partner: UNT Libraries Government Documents Department

Continuous bench-scale slurry catalyst testing: Direct coal liquification of Rawhide sub-bituminous coal. Technical report, July 1995--December 1995

Description: In 1994 extensive tests were conducted in the Exxon Research and Engineering Recycle Coal Liquefaction Unit (RCLU) in Baton Rouge, Louisiana. The work conducted in 1994 explored a variety of dispersed iron molybdenum promoted catalyst systems for direct coal liquefaction of Rawhide subbituminus coal. The goal was to identify the preferred iron system. We learned that among the catalysts tested, all were effective; however, none showed a large process advantage over the others. In 1995, we tested dispersed molybdenum catalysts systems for direct coal liquefaction on a second subbituminous coal, Black Thunder. Catalyst properties are shown in Table 1. We also checked a molybdenum promoted iron case, as well as the impact of process variables, such as sulfur type, hydrogen treat rate, and catalyst addition rate, as shown in Table 2. In 1995, we ran 18 material balances over a 7 week period, covering 7 conditions. This report covers the 1995 operations and results.
Date: May 24, 1996
Creator: Coless, L.A.; Poole, M.C. & Wen, M.Y.
Partner: UNT Libraries Government Documents Department

A characterization and evaluation of coal liquefaction process streams. Quarterly technical progress report, July 1, 1996--September 30, 1996

Description: CONSOL completed characterization of 64 samples from five run conditions of HTI Run ALC-1 (227-94), in which raw and cleaned (oil-agglomerated at low pH) Black Thunder Mine subbituminous coal was fed and processed using only dispersed catalysts in the liquefaction reactors. Extraction of THF-soluble resid from the pressure-filter cakes was more complete when agglomerates were fed, leaving only 5% or less THF solubles in the extracted cakes. When raw coal was fed, the extracted cakes contained 9-34% THF solubles. HTI also observed improved filtration during the periods that agglomerates were fed. Improved operability, if verified by additional work, could be an economically significant benefit of coal cleaning by oil agglomeration at low pH. An apparently higher Mo addition rate (see fourth bullet) may have contributed to the benefits of using oil-agglomerated coal. Other stream sample characteristics changed when oil-agglomerated coal was fed in Conditions 2-4, relative to when uncleaned coal was fed in Conditions 1 and 5. The ash content of the 0-6 bottoms samples was lower when oil-agglomerates were fed. The THF-soluble 524{degrees}C+ resid concentration in the feed slurry doubled when agglomerated coal was fed. Three factors may have influenced these characteristics. Higher coal conversion would have produced more resid. More efficient toluene-extraction of the filter cake would have recycled more resid. Removal of distillate as product to offset oil fed as part of the agglomerated coal would preferentially recycle the heaviest components.
Date: August 1, 1997
Creator: Robbins, G.A.; Brandes, S.D. & Winschel, R.A.
Partner: UNT Libraries Government Documents Department

Exploratory research on novel coal liquefaction concept. Quarterly report, October 1, 1996--December 31, 1996

Description: A goal of this work was to reduce the cost associated with hydrogen ion reagent `A`. Microautoclave tests were previously conducted using `A`/dry coal = 1.0. This quarter test were completed using a ratio of 2.0. Conversion was poor at the low ratio. Additional reagents did not improve the conversion.
Date: February 17, 1997
Creator: Winschel, R.A.; Brandes, S.D. & Derbyshire, F.J.
Partner: UNT Libraries Government Documents Department


Description: This is the Technical Progress Report for the sixteenth quarter of activities under DOE Contract No. DE-AC22-94PC93054. It covers the period April 1 through June 30, 1998. Described in this report are the following activities: (1) CONSOL characterized nine process stream samples received from Exxon Recycle Coal Liquefaction Unit (RCLU) operations conducted in 1994 with Rawhide Mine Wyoming subbituminous coal and all-dispersed Fe and Mo catalysts. (2) The University of Delaware subcontract related to resid reactivity was completed with issuance of the Topical Report covering work performed by Delaware. (3) Computational studies of the coal liquefaction resid models developed at the University of Delaware were continued at CONSOL R and D. The two reaction models, consisting of the reaction optimization and reaction once-through programs, were the focus of these studies. The updated resid structure data and results were used in the reaction models to predict percent conversion values that were compared with the experimentally-measured values from the University of Delaware. (4) Small samples of high-sulfur Hondo resid and anthracene oil were shipped to John Verkade of Iowa State University at his request. Verkade is testing a desulfurization method.
Date: February 1, 1999
Creator: Robbins, G.A.; Brandes, S.D.; Pazuchanics, D.J.; Nichols, D.G. & Winschel, R.A.
Partner: UNT Libraries Government Documents Department

Novel nanodispersed coal liquefaction catalysts: Molecular design via microemulsion-based synthesis. Technical progress report, October 1992--December 1992

Description: The objective of this project is to pursue the development of highly dispersed and inexpensive catalysts for improved coal solubilization and upgrading of coal liquids. A novel study of the synthesis of liquefaction catalysts of manometer size is being carried out. It is based on the molecular design of reverse micelles (microemulsions). These surfactant-stabilized, metal-bearing microdrops offer unique opportunities for synthesizing very small particles by providing a cage-like effect that limits particle nucleation, growth and agglomeration. The emphasis is on molybdenum- and iron-based catalysts, but the techniques being developed should also be generally applicable. The size of these very small and monodispersed particles will be accurately determined both separately and after in situ and ex situ coal impregnation. The as-prepared nanoparticles as well as the catalyst-impregnated coal or char matrix are characterized using a battery of techniques, including dynamic light scattering, x-ray diffraction and transmission electron microscopy. Catalytic activity tests are conducted under standardized coal liquefaction conditions. The effect of particle size of these unsupported catalysts on the product yield and distribution during conversion of a bituminous and a subbituminous coal are being determined.In this quarter, the synthesis of molybdenum sulfide in a microemulsion system with an alcohol-to-surfactant mass ratio of 3.5 is reported.
Date: February 1, 1993
Creator: Boakye, E.; Vittal, M. & Osseo-Asare, K.
Partner: UNT Libraries Government Documents Department


Description: The technical feasibility of separating mineral matter and pyrite from coal as it is transported from pulverizers to burners in pulverized coal combustion units will be examined. The charge imparted on coal during pulverization and transport to pulverized coal (PC) burners in a utility boiler will be quantified. In addition to field charge measurements, an existing computational model will be extended to numerically simulate charged particle motion in a turbulent gas through an electric field. Results from the field tests and numerical modeling will be employed in design and construction of a laboratory scale pulverizer/classifier. This laboratory unit will be used to quantify the magnitude and differential charge imparted on bituminous and subbituminous coals during pulverization and classification at temperatures and with gaseous constituents typical to utility PC units. An electrostatic separator, designed for in-line operation between pulverizers and PC boilers, will be used to clean prepulverized coals. Theoretical and experimental data are to be used in preparing a preliminary design for a full-scale, (15 ton/hr) in-line, electrostatic coal cleaning device. Finally, the economic potential for application to PC units will be assessed.
Date: July 1, 1998
Partner: UNT Libraries Government Documents Department

Task 5.4 -- Stable and supercritical chars. Semi-annual report, January 1--June 30, 1995

Description: The use of chars and carbons as absorbents and catalyst supports could be expanded if their stability to reactive gases were improved. The purpose of this task is to develop methods for applying surface coatings of boron carbide, silicon carbide, and titanium carbide on the char. Formation of these composites will increase stability and improve structural strength and, consequently, resistance to abrasion. The first objective of this task is to develop methods for coating low-rank coal (LRC) chars and carbons by chemical vapor deposition (CVD) to produce high surface area composites that are inert to reactive atmospheres. The proposed coating layers will be formed from elements known to form extremely hard and stable carbide materials. The second objective is to determine the feasibility of using supercritical extraction to prepare an activated carbon with a very high surface area. During this report period supercritical solvent extraction was investigated as a means of producing very large microporous structures in chars. Wyodak subbituminous coal, Gascoyne lignite, and Velva lignite were used for the supercritical extractions.
Date: December 31, 1995
Creator: Olson, E.S. & Sharma, R.K.
Partner: UNT Libraries Government Documents Department

Drying and reconstitution of subbituminous coal - CRADA 90-004. Final report

Description: AMAX Coal Company (AMAX) has built a 200 tph, demonstration scale fluidized-bed drying process at their Belle Ayr Mine in Wyoming to dry the subbituminous coal of Wyodak seam from an average moisture content of 25-30 wt% to about 10 wt%. Currently, the dryer generates too many fines for proper transportation and handling. Though the raw coal is about 2-inch top size, about 80 wt% of the dryer product ends up finer than 28 mesh, and about 10 wt% of the dried coal is collected in the dryer bag house (minus 200 mesh). Paul Woessner, Director of Research and Development of AMAX, met with personnel from PETC Coal Preparation Division and expressed an interest in an investigation of the feasibility of applying the PETC`s humic acid binder to reconstitute the bag house fines from the dryer. This was an area in which PETC had been doing some research and had some expertise. As a result, AMAX and the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) signed a Cooperative Research and Development Agreement (CRADA, see appendix A) in June 1990 to produce, from fine subbituminous coal, economic low moisture reconstituted solid fuel forms that have suitable storage, handling, transportation, and combustion properties. PETC`s task in this agreement was to conduct broad, baseline studies in three areas: (1) to develop a humic acid binder from AMAX subbituminous coal using the PETC-developed Humic Acid Binder Process, (2) to reconstitute AMAX`s dried subbituminous coal fines from the bag house and the fluidized bed dryer product with humic acid binder, and (3) to produce low moisture, water-resistant pellets from raw subbituminous coal by the PETC-developed Lignipel Process. AMAX, on the other hand, agreed to produce 1-2 tons of reconstituted solid fuel for handleability and combustion tests and partially funded PETC`s efforts.
Date: October 30, 1991
Creator: Wen, W.W.; Nowak, M.A. & Killmeyer, R.P.
Partner: UNT Libraries Government Documents Department

Energy and environmental research emphasizing low-rank coal: Task 3.9 catalytic tar cracking

Description: Tar produced in the gasification of coal is deleterious to the operation of downstream equipment, including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure-swing absorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means of removing these tars from gas streams and, in the process, generating useful products, such as methane gas, which is crucial to operation of molten carbonate fuel cells. Aerosol tars are not readily removed from gas streams by conventional means and, as a consequence, often end up plugging filters or fouling fuel cells, turbines, or sorbents. Catalytic cracking of these tars to molecular moieties of C{sub 10} or smaller would prevent the problems commonly attributed to the tars. As an example, the moving Bourdon fixed-bed gasifier, by virtue of its efficient countercurrent heat exchange and widespread commercial use, may offer the lowest-cost integrated gasification combined-cycle (IGCC) system if tar generation and wastewater contamination can be minimized. We evaluate the potential of selected catalysts to minimize tar accumulation and maximize char conversion to useful liquid and/or gaseous products. Owing to the potential for production of extremely toxic nickel carbonyl gas, care must be exercised in the use of a NISMM catalyst for cracking tars at high temperatures in reducing atmospheres such as those produced by coal gasification. We observed a fifty percent or more of tar produced during steam gasification of Beulah lignite at temperatures of 400{degrees}-800+{degrees}C when cracked by either dolomite or zeolite maintained at a temperature of 50{degrees}C-100{degrees}C below that of the reactor.
Date: September 1, 1995
Creator: Timpe, R.C.
Partner: UNT Libraries Government Documents Department

Advanced progress concepts for direct coal liquefaction

Description: Given the low cost of petroleum crude, direct coal liquefaction is still not an economically viable process. The DOE objectives are to further reduce the cost of coal liquefaction to a more competitive level. In this project the primary focus is on the use of low-rank coal feedstocks. A particular strength is the use of process-derived liquids rather than model compound solvents. The original concepts are illustrated in Figure 1, where they are shown on a schematic of the Wilsonville pilot plant operation. Wilsonville operating data have been used to define a base case scenario using run {number_sign}263J, and Wilsonville process materials have been used in experimental work. The CAER has investigated: low severity CO pretreatment of coal for oxygen rejection, increasing coal reactivity and mg inhibiting the propensity for regressive reactions; the application of more active. Low-cost Fe and Mo dispersed catalysts; and the possible use of fluid coking for solids rejection and to generate an overhead product for recycle. CONSOL has investigated: oil agglomeration for coal ash rejection, for the possible rejection of ash in the recycled resid, and for catalyst addition and recovery; and distillate dewaxing to remove naphthenes and paraffins, and to generate an improved quality feed for recycle distillate hydrogenation. At Sandia, research has been concerned with the production of active hydrogen donor distillate solvent fractions produced by the hydrogenation of dewaxed distillates and by fluid coking via low severity reaction with H{sub 2}/CO/H{sub 2}O mixtures using hydrous metal oxide and other catalysts.
Date: September 1, 1995
Creator: Anderson, R.; Derbyshire, F. & Givens, E.
Partner: UNT Libraries Government Documents Department

Exploratory Research on Novel Coal

Description: The report presents the findings of work performed under DOE Contract No. DE-AC22 -95PC95050, Task 3 - Flow Sheet Development. A novel direct coal liquefaction technology was investigated in a program being conducted by CONSOL Inc. with the University of Kentucky Center for Applied Energy Research and LDP Associates. The process concept explored consists of a first-stage coal dissolution step in which the coal is solubilized by hydride ion donation. In the second stage, the products are catalytically upgraded to refinery feedstocks. Integrated first-stage and solids-separation steps were used to prepare feedstocks for second-stage catalytic upgrading. An engineering and economic evaluation was conducted concurrently with experimental work throughout the program. Parameters were established for a low-cost, low-severity first-stage reaction system. A hydride ion reagent system was used to effect high coal conversions of Black Thunder Mine Wyoming subbituminous coal. An integrated first-stage and filtration step was successfully demonstrated and used to produce product filtrates with extremely low solids contents. High filtration rates previously measured off-line in Task 2 studies were obtained in the integrated system. Resid conversions of first-stage products in the second stage were found to be consistently greater than for conventional two-stage liquefaction resids. In Task 5, elementally balanced material balance data were derived from experimental results and an integrated liquefaction system balance was completed. The economic analysis indicates that the production of refined product (gasoline) via this novel direct liquefaction technology is higher than the cost associated with conventional two-stage liquefaction technologies. However, several approaches to reduce costs for the conceptual commercial plant were recommended. These approaches will be investigated in the next task (Task 4) of the program.
Date: May 1, 1998
Creator: Winschel, R.A. & Brandes, S.D.
Partner: UNT Libraries Government Documents Department

Hydrothermally treated coals for pulverized coal injection. Final technical report

Description: This project investigated the suitability of hydrothermally dried low-rank coals for pulverized fuel injection into blast furnaces in order to reduce coke consumption. Coal samples from the Beluga coalfield and the Usibelli Coal Mine, Alaska, were used for the study. Crushed coal samples were hydrothermally treated at three temperatures, 275, 300 and 325{degrees}C, for residence times of 10, 60 and 120 minutes. Products were characterized to determine their suitability for pulverized coal injection. Characterization included proximate and ultimate analyses, vitrinite reflectance and TGA reactivity. A literature survey was also conducted.
Date: October 1, 1995
Creator: Walsh, D.E.; Rao, P.D.; Ogunsola, O. & Lin, H.K.
Partner: UNT Libraries Government Documents Department