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Preconversion processing of bituminous coals: New directions to improved direct catalytic coal liquefaction

Description: Improved coal liquefaction was reinvestigated for the current two-stage process on the basis of the associated molecular nature of coal. Since a significant portion of coal molecules are physically associated as pointed in our recent paper, physical dissolution should be considered. The step-wise, high-temperature soaking is a simple and effective method for coal dissolution. Larger dissolution makes liquefaction severity lower. Broad molecular mass distribution in the associated coal was another important factor. The selective reaction of fractions with high molecular weight isolated after the high-temperature soaking makes gas yield lower. Tests using an autoclave by the concept shown in Figure 5 enabled to more oil and 15-20% less gas yields. It is expected that the procedure will result in great cost reduction in coal liquefaction.
Date: January 1, 1993
Partner: UNT Libraries Government Documents Department

Analysis of photographic records of coal pyrolysis

Description: Bituminous coals upon heating undergo melting and pyrolytic decomposition with significant parts of the coal forming an unstable liquid that can escape from the coal by evaporation. The transient liquid within the pyrolyzing coal causes softening or plastic behavior that can influence the chemistry and physics of the process. Bubbles of volatiles can swell the softened coal mass in turn affecting the combustion behavior of the coal particles. The swelling behavior of individual coal particles has to be taken into account both as the layout as well as for the operation of pyrolysis, coking and performance of coal-fired boilers. Increased heating rates generally increase the amount of swelling although it is also known that in some cases, even highly swelling coals can be transformed into char with no swelling if they are heated slowly enough. The swelling characteristics of individual coal particles have been investigated by a number of workers employing various heating systems ranging from drop tube and shock tube furnaces, flow rate reactors and electrical heating coils. Different methods have also been employed to determine the swelling factors. The following sections summarize some of the published literature on the subject and outline the direction in which the method of analysis will be further extended in the study of the swelling characteristics of hvA bituminous coal particles that have been pyrolyzed with a laser beam.
Date: October 1, 1991
Creator: Dodoo, J.N.D.
Partner: UNT Libraries Government Documents Department

Preconversion processing of bituminous coals: New directions to improved direct catalytic coal liquefaction. [Effect of pretreatment before liquefaction]

Description: The main task of this quarter was to install reactors to conduct preconversion and liquefaction of coal. Coal and coal liquids were collected. The anaerobic chamber (Model 855-AC; Plas Labs, inc.) was procured and set up to store coal samples under an inert gas. Equipment to treat products was assembled, including Soxhlet extraction units, fractionation columns, a distillation column, and a rotary evaporator. Two gas chromatographs for analysis of gases and liquid were adjusted. Two reactor systems were installed for the experimental apparatus. One was Model 4576 high-temperature and high-pressure autoclave (Parr Instrument, 500{degrees}C and 5000 psi) (see Figure 1); the other was a 27 ml of microreactors. The autoclave was obtained from the manufacturer and assembled. The experimental set-up of microreactors are shown in Figure 2.
Date: July 1, 1992
Partner: UNT Libraries Government Documents Department

Ultrafine structure of coal determined by electron microscopy

Description: The shape and size of pores in two high volatile bituminous coals of differing lithotypes have been directly observed by means of transmission electron microscope (TEM). The distribution of the porosity with respect to their maceral associations were ascertained as were the sizes and distributions of the micro minerals. The use of stereo pairs reveals the interconnectivity of the pores in micro volumes of the macerals indicating a high degree of permeability within those regions. The finest porosity was observed in vitrinite fragments of both coals and ranged in size from under 2 nm to 20 nm in diameter, with the majority in the smaller end of the size range. On the other hand, inertinite appears to be the most porous maceral and typically contains a broad range of pores from 5 through 30 nm. Much of the inertinite is granular material varying from fine to coarse grained particles with the former corresponding to micrinite. Finally, the least porous maceral is exinite which generally appears as a featureless material except for the presence of irregular and tubular pores thought to be initiated by the catalytic action of minerals. The intimate relationship between exinite and inertinite such as exists in durains, where the inertinite contains large amounts of fine mineral matter, may therefore promote the generation of porosity in exinites.
Date: January 1, 1979
Creator: Harris, L A & Yust, C S
Partner: UNT Libraries Government Documents Department

Catalyst dispersion and activity under conditions of temperature-staged liquefaction

Description: This research program involves the investigation of the use of highly dispersed catalyst precursors for the pretreatment of coals by mild hydrogenation. During the course of this effort solvent preswelling of the coal was evaluated as a means of deeply impregnating catalysts into coal, active phases of catalysts under reaction conditions were studied and the impact of these techniques were evaluated during pretreatment and temperature-staged liquefaction. Two coals, a Texas subbituminous and a Utah high volatile A bituminous, were used to examine the effects of solvent swelling pretreatment and catalyst impregnation on conversion behavior at 275[degrees]C, representative of the first, low-temperature stage in a temperature-staged liquefaction reaction. Ferrous sulfate, iron pentacarbonyl, ammonium tetrathiomolybdate, and molybdenum hexacarbonyl were used as catalyst precursors. Without swelling pretreatment, impregnation of both coals increased conversion, mainly through increased yields of preasphaltenes.
Date: February 1, 1993
Creator: Davis, A.; Schobert, H.H.; Mitchell, G.D. & Artok, L.
Partner: UNT Libraries Government Documents Department

Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

Description: a study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. This document is the eighth quarterly report prepared in accordance with the project reporting requirements covering the period from July 1,1990 to September 30, 1990. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. The data from the basic research on coal surfaces, bench scale testing and proof-of-concept scale testing will be utilized to design a final conceptual flowsheet. The economics of the flowsheet will be determined to enable industry to assess the feasibility of incorporating the advanced fine coal cleaning technology into the production of clean coal for generating electricity. 22 figs., 11 tabs.
Date: January 1, 1990
Partner: UNT Libraries Government Documents Department

AFBC co-firing of coal and hospital waste

Description: The unit to be installed at Lebanon Veteran's Affairs Medical Center will prove that circulating fluidized bed combustion can provide economically viable and efficient hospital waste destruction and steam generation. The State permitting process is proceeding. The air quality division of the Department of Environmental Resources has requested the use of anthracite coal only. Anthracite has a much lower sulfur content than bituminous coal. The use of the anthracite coal has been approved by the Department of Veteran's Affairs. The DER permit will specify the use of antrhacite coal. The State permitting approval is expected in the near future. Testing with the shredding system at the Donlee Pilot facility has been completed. The results predict the Lebanon VA facility will meet both NSPS regulations and the BAT guidelines proposed by the State of Pennsylvania. There have been no significant problems encountered to date.
Date: May 29, 1992
Creator: Coulthard, E.J. & Roy, R.R.
Partner: UNT Libraries Government Documents Department

Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama

Description: This report presents the results of Run 261 performed at the Advanced Coal Liquefaction R D Facility in Wilsonville, Alabama. The run started on January 12, 1991 and continued until May 31, 1991, operating in the Close-Coupled Integrated Two-Stage Liquefaction mode processing Illinois No. 6 seam bituminous coal (from Burning star No. 2 mine). In the first part of Run 261, a new bimodal catalyst, EXP-AO-60, was tested for its performance and attrition characteristics in the catalytic/catalytic mode of the CC-ITSL process. The main objective of this part of the run was to obtain good process performance in the low/high temperature mode of operation along with well-defined distillation product end boiling points. In the second part of Run 261, Criterion (Shell) 324 catalyst was tested. The objective of this test was to evaluate the operational stability and catalyst and process performance while processing the high ash Illinois No. 6 coal. Increasing viscosity and preasphaltenes made it difficult to operate at conditions similar to EXP-AO-60 catalyst operation, especially at lower catalyst replacement rates.
Date: September 1, 1992
Partner: UNT Libraries Government Documents Department

Coal plasticity at high heating rates and temperatures

Description: Effects of pressure, temperature, and coal type on coal plasticity were investigated. Seven coals, from the Argonne premium sample bank ranging from lignite to low volatile bituminous, were studied. Elevated pressures, up to 10 atm of helium, did not affect coal plasticity, but reducing pressure from atmosphere to vacuum resulted in diminished plasticity, i.e. a shorter plastic period and a higher minimum apparent viscosity. It is hypothesized that high pressure inhibits mass transport of metaplast to tar vapors, but also favors metaplast repolymerization into coke and char. Higher holding temperature decreased the coal plastic period. It is hypothesized that higher temperature increases mass transport of liquid metaplast to tar vapors and metaplast repolymerization to coke and char. Heating rate had essentially no effect on the individual softening temperatures of five different plastic coals. Possible explanations are that, depending on coal type, metaplast generation, by chemical bond breaking or physical melting, or both, is not strongly affected by heating rate. In particular, for medium and low volatile bituminous cools, there is evidence that generation of the metaplast responsible for initial softening involves largely chemical bond breaking as opposed to physical melting.
Date: September 1, 1992
Creator: Gerjarusak, S.; Peters, W.A. & Howard, J.B.
Partner: UNT Libraries Government Documents Department

A novel approach to highly dispersing catalytic materials in coal for gasification

Description: This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and high catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. The work is focused on the elucidation of coal-catalyst precursor interactions in solution and the variables which control the adsorption and dispersion of coal gasification metal catalysts. In order to optimize coal-metal ion interactions and hence maximize catalyst activity, the study examines the surface electrochemistry of a lignite, a subbituminous, and a bituminous coals and their demineralized and oxidized derivatives prior to loading with the catalytic materials. The surface electrical properties of the coals are investigated with the aid of electrophoresis, while the effects of the surface charge on the adsorption of K{sup +} and Ca{sup 2+} are studied by agitating the coals with aqueous solutions of potassium and calcium. A zeta meter, a tube furnace, and other equipment required for the investigation have been acquired and installed. Preliminary work shows that the lignite (Psoc 1482) is negatively charged between pH 1.8 and pH 11.0 and has an isoelectric point of pH 1.8.
Date: January 1, 1989
Creator: Abotsi, G.M.K. & Bota, K.B.
Partner: UNT Libraries Government Documents Department

Pelletizing/reslurrying as a means of distributing and firing clean coal

Description: The objective of this study is to develop technology that permits the practical and economic preparation, storage, handling, and transportation of coal pellets, which can be reslurried into Coal water fuels (CWF) suitable for firing in small- and medium-size commercial and industrial boilers, furnaces, and engines. The project includes preparing coal pellets and capsules from wet filter cake that can be economically stored, handled, transported, and reslurried into a CWF that can be suitably atomized and fired at the user site. The wet cakes studied were prepared from ultra-fine (95% -325 mesh) coal beneficiated by advanced froth-flotation techniques. The coals studied included two eastern bituminous coals, one from Virginia (Elkhorn) and one from Illinois (Illinois No. 6) and one western bituminous coal from Utah (Sky Line coal).
Date: March 17, 1992
Creator: Conkle, H.N.
Partner: UNT Libraries Government Documents Department

Assessment of underground coal gasification in bituminous coals: catalog of bituminous coals and site selection. Appendix A. National coal resource data system: Ecoal, Wcoal, and Bmalyt. Final report, Phase I. [Bituminous coal; by state; coal seam depth and thickness; identification]

Description: Appendix A is a catalog of the bituminous coal in 29 states of the contiguous United States which contain identified bituminous coal resources.
Date: January 31, 1982
Partner: UNT Libraries Government Documents Department

Flash hydropyrolysis of coal. Quarterly report No. 9, April 1-June 30, 1979

Description: Both the North Dakota lignite and New Mexico sub-bituminous coal have been hydrogasified in the Flash Hydropyrolysis unit with yields ranging up to about 85 to 90% conversion of the available carbon at 2500 psi and 875 to 900/sup 0/C. The lignite appears to be less reactive at lower pressure than the sub-bituminous coal, producing an average of 40% gaseous yield at 1000 psi and 900/sup 0/C while the sub-bituminous produced over 50%. The reactivity of both coals is dependent on the hydrogen partial pressure but does not appear to be affected by H/sub 2//coal feed ratio. When the H/sub 2//coal ratio was reduced to 0.05 and sub-bituminous coal was run at 2500 psi and 875/sup 0/C, a high methane concentration of 57% was achieved. However, the yield or conversion of carbon to gas was limited to 30% which may be attributed to the reduction in hydrogen partial pressure during the run. Further work is being planned to obtain additional data at the lower pressure and H/sub 2//coal feed ratios. Illinois No. 6 coal, a caking bituminous, has been successfully run in the experimental equipment both treated with calcium and untreated. A reaction model, previously developed, has been modified and is being fitted to all the lignite data to produce one consistent set of pre-exponential factors and activation energies for the reaction rate equations. The experimental equipment is being modified to allow varying feed composition and especially introduction of steam into the feed gas.
Date: October 1, 1979
Partner: UNT Libraries Government Documents Department

Development and evaluation of an automated reflectance microscope system for the petrographic characterization of bituminous coals

Description: The development of automated coal petrographic techniques will lessen the demands on skilled personnel to do routine work. This project is concerned with the development and successful testing of an instrument which will meet these needs. The fundamental differences in reflectance of the three primary maceral groups should enable their differentiation in an automated-reflectance frequency histogram (reflectogram). Consequently, reflected light photometry was chosen as the method for automating coal petrographic analysis. Three generations of an automated system (called Rapid Scan Versions I, II and III) were developed and evaluated for petrographic analysis. Their basic design was that of a reflected-light microscope photometer with an automatic stage, interfaced with a minicomputer. The hardware elements used in the Rapid Scan Version I limited the system's flexibility and presented problems with signal digitization and measurement precision. Rapid Scan Version II was designed to incorporate a new microscope photometer and computer system. A digital stepping stage was incorporated into the Rapid Scan Version III system. The precision of reflectance determination of this system was found to be +- 0.02 percent reflectance. The limiting factor in quantitative interpretation of Rapid Scan reflectograms is the resolution of reflectance populations of the individual maceral groups. Statistical testing indicated that reflectograms were highly reproducible, and a new computer program, PETAN, was written to interpret the curves for vitrinite reflectance parameters ad petrographic.
Date: October 1, 1980
Creator: Hoover, D. S. & Davis, A.
Partner: UNT Libraries Government Documents Department

Conspray dynamic sleeve piston coal feeder. Phase II. Verification tests. Final technical report

Description: This report details the performance of Phase II: Verification Tests of the Conspray dynamic sleeve piston coal feeder. The machine performed for 200 hours at 700 psi backpressure, utilizing a 70% to 200 mesh Utah bituminous coal as feedstock. All test work was satisfactorily completed. A post-test inspection was performed. A report of component wear and failures incurred in testing is included as well as suggestions for machine upgrades. The overall conclusion is that the dynamic sleeve piston feeder has proven its ability to operate safely and reliably. When problems have occurred, the machine has demonstrated inherent safety by shutting down without endangering process or personnel. With the recommended improvements incorporated into the feeder, the unit will be ready for installation on a pilot scale coal gasifier. 9 figures, 11 tables.
Date: January 26, 1984
Partner: UNT Libraries Government Documents Department

Graphic values for some organic constitutents of beneficiated coal samples

Description: Graphic techniques exist which can accurately predict values for calorific value, organic sulfur, and possibly other constituents of the organic portion of beneficiated coal sample fractions. These techniques also permit a determination of coal rank to be made without the use of the approximations required in the standard procedure. Fractions of IBC-101 with varying ash contents were produced by froth flotation. The various fractions were analyzed by the coal analysis laboratory and the particular data type was plotted in each case vs. the individual ash content of each fraction, using Lotus 123 and Freelace software packages. Such plots for calorific value and organic sulfur have, so far, been made. These curves and the information they contain are discussed in this report. A comparison of the graphic mineral matter value with the usual one calculated from the Parr approximation has been made. Eventually, the data may lead to an effective way to estimate inorganic carbon, hydrogen, nitrogen, and other organic constitents of coal. All data will be made available to researchers.
Date: January 1, 1992
Creator: Kohlenberger, L.B. (Illinois State Geological Survey, Champaign, IL (United States))
Partner: UNT Libraries Government Documents Department

A surface area/porosity investigation of four coals: Upper Freeport; Illinois No. 6; New Zealand Stockton; and Panther Valley

Description: This project had as its primary objective the establishment of the specific surface areas (SSAs) and the qualitative definition of any existing pore structure of four coal samples supplied by Dr. Robert Good of the Chemical Engineering Department of the State University of New York at Buffalo. The samples included three bituminous coals (Upper Freeport, Illinois No. 6 and New Zealand Stockton) and one Anthracite (Panther Valley Mine).
Date: January 1, 1990
Creator: Good, R.J.; Cadenhead, D.A. & Asgharian, B.
Partner: UNT Libraries Government Documents Department

Surface electrochemical control for fine coal and pyrite separation

Description: Ongoing work includes the characterization of coal pyrites, the floatability evaluation of typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces.
Date: January 1, 1990
Creator: Chen, Wanxiong; Hu, Weibai; Wann, Jyi-Perng; Zhu, Ximeng; Bodily, D.M. & Wadsworth, M.E.
Partner: UNT Libraries Government Documents Department

Surface electrochemical control for the fine coal and pyrite separation

Description: Ongoing work includes the characterization of coal pyrites, the floatability evaluation of typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces.
Date: January 1, 1989
Creator: Chen, Wanxiong; Hu, Weibai; Wann, Jyi-Perng; Zhu, Ximeng & Wadsworth, M.E.
Partner: UNT Libraries Government Documents Department

Surface magnetic enhancement for coal cleaning

Description: The fundamental chemistry for selective adsorption of magnetizing reagent on coal-associated minerals to enhance the magnetic susceptibilities of minerals have been established in Phase 1 study. The application of the results on coal cleaning for the Phase 2 study is completed this quarter. Illinois No. 6, Ohio Lower Kittanning, and West Virginia Pocahontas coals have been investigated to determine the most effective way of using the magnetizing method for coal cleaning. The results show that the best separation performance is obtained on finely ground coals. Up to 91% ash reduction (from 22% to 3.3% ash content) and 93% pyritic sulfur reduction at 70% BTU recovery can be obtained with the magnetizing approach when Illinois No. 6 coal is processed at 90% passing 500 mesh. Even at a coarser sizes such as 90% passing 200 mesh, 86% ash reduction and 87% pyritic sulfur reduction with 74% coal TBU recovery can still be obtained. Similar results are obtained for Lower Kittanning and Pocahontas coal.
Date: January 1, 1990
Creator: Hwang, J.Y.
Partner: UNT Libraries Government Documents Department

Surface magnetic enhancement for coal cleaning

Description: The fundamental chemistry for selective adsorption of magnetizing reagent on coal-associated minerals to enhance the magnetic susceptibilities of minerals have been established in Phase I study. The application of the results on coal cleaning is in progress in the Phase II study. Illinois No. 6, Ohio Lower Kittanning, and West Virginia Pocahontas coals are investigated during this reporting period to determine the most effective way of using the magnetizing method for coal cleaning. The results show that the best separation performance is obtained on finely ground coals. Up to 91% ash reduction (from 22% to 3.3% ash content) at 70% coal recovery can be obtained with the magnetizing approach when Illinois No. 6 coal is processed at 90% passing 500 mesh. Even at a coarser sizes such as 90% passing 200 mesh, 86% ash reduction with 71% coal recovery can still be obtained. Although the results are probably better than using the froth flotation method, direct comparison tests will be conducted in the next reporting period.
Date: January 1, 1990
Creator: Hwang, J.Y.
Partner: UNT Libraries Government Documents Department

Prediction and measurement of entrained flow coal gasification processes. Interim report, September 8, 1981-September 7, 1983

Description: This volume reports interim experimental and theoretical results of the first two years of a three year study of entrained coal gasification with steam and oxygen. The gasifier facility and testing methods were revised and improved. The gasifier was also modified for high pressure operation. Six successful check-out tests at elevated pressure were performed (55, 75, 100, 130, 170, and 215 psig), and 8 successful mapping tests were performed with the Utah bituminous coal at an elevated pressure of 137.5 psig. Also, mapping tests were performed at atmospheric pressure with a Utah bituminous coal (9 tests) and with a Wyoming subbituminous coal (14 tests). The LDV system was used on the cold-flow facility to make additional nonreactive jets mixing measurements (local mean and turbulent velocity) that could be used to help validate the two-dimensional code. The previously completed two-dimensional entrained coal gasification code, PCGC-2, was evaluated through rigorous comparison with cold-flow, pulverized coal combustion, and entrained coal gasification data. Data from this laboratory were primarily used but data from other laboratories were used when available. A complete set of the data used has been compiled into a Data Book which is included as a supplemental volume of this interim report. A revised user's manual for the two-dimensional code has been prepared and is also included as a part of this interim report. Three technical papers based on the results of this study were published or prepared. 107 references, 57 figures, 35 tables.
Date: January 31, 1984
Creator: Hedman, P.O.; Smoot, L.D.; Fletcher, T.H.; Smith, P.J. & Blackham, A.U.
Partner: UNT Libraries Government Documents Department

Mechanisms governing fine particulate emissions from coal flames

Description: The overall objectives of this project are to provide a basic understanding of the principal processes that govern fine particulate formation in pulverized coal flames. This understanding is to be used to develop a model (or models) which will predict the yield and size distribution of fine particulates as a function of coal type, coal processing, and combustion conditions. The goal of the model is to provide an engineering tool that will enable the practitioner to estimate the consequences of design decisions and fuel selection on the fine particulate yield. The practitioner can then make rational decisions regarding the required technology and costs associated with effluent cleanup while still in the design phase.
Date: February 1, 1989
Creator: Kramlich, J.C.; Newton, G.H.; Socha, R.G. & Clark, W.D.
Partner: UNT Libraries Government Documents Department