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Applications of scanning electron microscopy to the study of mineral matter in peat

Description: Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) have been used for in situ analysis of minerals in peats by combining methods for producing oriented microtome sections of peat with methods for critical point drying. The combined technique allows SEM analysis of the inorganic components and their associated botanical constituents, along with petrographic identification of the botanical constituents. In peat deposits with abundant fluvial- or marine-derived minerals, one may use the above technique and/or medium- or low-temperature ashing followed by x-ray diffraction to readily identify the various mineral components. However, in some freshwater environments the scarcity of non-silica minerals makes the above techniques impractical. By separating the inorganic residues from the peat, one can isolate the non-silica mineral matter in the SEM for analysis by EDS. Furthermore, such separation allows SEM analysis of features and textures of both silica and non-silica mineral particles that might otherwise be unidentifiable. Results indicate the occurrence of detritial minerals in both Okefenokee and Snuggedy Swamp peats, the presence of authigenic or diagenetic minerals growing within peats, and dissolution features on freshwater sponge spicules that may account for the absence of spicules in Tertiary lignites.
Date: January 1, 1983
Creator: Raymond, R. Jr.; Andrejko, M.J. & Bardin, S.W.
Partner: UNT Libraries Government Documents Department

Phase equilibria for complex fluid mixtures

Description: After defining complex mixtures, attention is given to the canonical procedure used for the thermodynamics of fluid mixtures: first, we establish a suitable, idealized reference system and then we establish a perturbation (or excess function) which corrects the idealized system for real behavior. For complex mixtures containing identified components (e.g. alcohols, ketones, water) discussion is directed at possible techniques for extending to complex mixtures our conventional experience with reference systems and perturbations for simple mixtures. Possible extensions include generalization of the quasi-chemical approximation (local compositions) and superposition of chemical equilibria (association and solvation) on a physical equation of state. For complex mixtures containing unidentified components (e.g. coal-derived fluids), a possible experimental method is suggested for characterization; conventional procedures can then be used to calculate phase equilibria using the concept of pseudocomponents whose properties are given by the characterization data. Finally, as an alternative to the pseudocomponent method, a brief introduction is given to phase-equilibrium calculations using continuous thermodynamics.
Date: April 1, 1983
Creator: Prausnitz, J.M.
Partner: UNT Libraries Government Documents Department

Establishment and maintenance of a Coal Sample Bank and data base

Description: During the period 7/9/92-10/8/92 a total of 80 samples (30 DOE Sample Bank samples and 50 other Penn State samples) of various sizes, not including DECS-17, were distributed. Fifteen of these samples were provided to DOE contractors. Six orders for a total of 80 30-gram bags of DECS-17 have been filled. All of these bags have been distributed to DOE dispersed catalyst contractors or those approved by DOE to receive the samples. A total of 188 data printouts were distributed. In addition, 15 special data requests were fulfilled by either search/sort and printout or creation of a data disk, resulting in distribution of limited information on over 1089 samples. Several preliminary requests for Sample Bank and Data Base information and price quotations have also been handled.
Date: November 23, 1992
Creator: Davis, A.
Partner: UNT Libraries Government Documents Department

Configurational diffusion of asphaltenes in fresh and aged catalyst extrudates

Description: The objective of this research is to determine the relationship between the size and shape of coal and petroleum macromolecules and their diffusion rates i.e., effective diffusivities, in catalyst pore structures. That is, how do the effective intrapore diffusivities depend on molecule configuration and pore geometry.
Date: January 21, 1992
Creator: Guin, J.A. & Tarrer, A.R.
Partner: UNT Libraries Government Documents Department

VHF EPR analysis of organic sulfur in coal

Description: This report covers progress made in the first yearly quarter of a two year investigation using novel, very high frequency electron paramagnetic resonance (VHF EPR) spectroscopy techniques and instrumentation (one of only two W-band spectrometers in existence) developed earlier by these authors, to conduct further qualitative and quantitative studies of heteroatomic organic molecules in coal with particular emphasis on sulfur. Previous W-band (96 GHz) work is being extended to studies of new model compounds as well as coal and desulfurized coal samples. Typically, the model compounds under investigation and their analogues are found in coals as stable free radicals which give rise to an EPR signal. The preparation of radicals from compounds having widely varying structures and physical properties in a stable environment has long been a very difficult task. To address this problem, the refinement of several new and very useful methods of preparing of these stable free radicals in various glasses, at catalytic surfaces, and in solution, are presented in this first report. Free radical generation was accomplished by both UV photolysis as well as chemical oxidation/reduction techniques. By these methods, over 25 new compounds, often commercially derived from coal extracts, have been prepared and studied by conventional X-band EPR (9 GHz). Several representative W-band spectra are also presented.
Date: January 1, 1991
Creator: Clarkson, R.B.
Partner: UNT Libraries Government Documents Department

Characterization of western coals and coal macerals by solid-state nuclear magnetic resonance spectroscopy. Progress report, August 1, 1981-January 31, 1982

Description: Two bituminous coals were selected on the basis of petrographic analysis as having high concentrations of vitrinite, inertinite and liptinite. These coal samples were ground up to about 10-3 ..mu..m, treated with HCl and HF to remove the mineral matter, and the macerals were separated by density gradient centrifugation. Structural features of the three different macerals were obtained by NMR analysis based on conventional CP/MAS and multiple pulse multi-dimensional /sup 13/C NMR spectroscopy. Results are presented in tabular form. (ATT)
Date: January 1, 1982
Creator: Pugmire, R.J. & Grant, D.M.
Partner: UNT Libraries Government Documents Department

Kinetics and mechanism of catalytic hydroprocessing of components of coal-derived liquids. Sixteenth quarterly report, February 16, 1983-May 15, 1983.

Description: A new method of structural analysis is applied to a group of hydroliquefied coal samples. The method uses elemental analysis and NMR data to estimate the concentrations of functional groups in the samples. The samples include oil and asphaltene fractions obtained in a series of hydroliquefaction experiments, and a set of 9 fractions separated from a coal-derived oil. The structural characterization of these samples demonstrates that estimates of functional group concentrations can be used to provide detailed structural profiles of complex mixtures and to obtain limited information about reaction pathways. 11 references, 1 figure, 7 tables.
Date: August 22, 1983
Creator: Gates, B. C.; Olson, H. H.; Schuit, G. C.A.; Stiles, A. B. & Petrakis, L.
Partner: UNT Libraries Government Documents Department

Analyses of tipple and delivered samples of coal collected during fiscal year 1985

Description: This Department of Energy (DOE) publication updates a series of Topical Reports (formerly ''Reports of Investigation'') on the quality of coal purchases under specifications for government use. Listed in alphabetical order by state, county, town, and mine are analytical data on the composition and quality of tipple and delivered samples of coal collected during the fiscal year 1985. Tipple samples were collected by certified commercial laboratories in accordance with instructions given by the Analytical Research Branch (ARB), Coal Science Division (CSD). The delivered samples were collected at destination by installation personnel, and all samples were analyzed under the supervision of the DOE-CSD located at the Pittsburgh Energy Technology Center (PETC), Pittsburgh, Pennsylvania, or the US Army General Material and Petroleum Activity Laboratory, located at New Cumberland, Pennsylvania.
Date: January 1, 1988
Creator: Schultz, H.; Retcofsky, H.L. & Davis, L.R.
Partner: UNT Libraries Government Documents Department

Computed tomography of coals. Quarterly technical progress report No. 1, August 16, 1982-November 28, 1982

Description: The purpose of this contract is to examine the utility and advantages of x-ray computed tomography (CT) for investigating the structure within coal and the changes that occur in these structures during such processes as combustion and gasification. The CT technique is noninvasive and nondestructive. It can produce interior views of the coal and, with a data acquisition time of ca 9 seconds, can be used for following many coal processes in real time. This is the first in-depth study of the application of the x-ray tomography technique to the problems in coal utilization, and consequently, considerable time will be spent in the early stages of this contract in examining CT pictures of coal and relating them to more conventional petrographic and mineral analyses. This phase of the work is being undertaken in Task 1 of the contract and is reported for this period. Building on this foundation, the succeeding tasks will follow changes in the coal structure during reaction. The first series of CT experiments is scheduled to take place on December 11-13, 1982, at the General Electric Company, Medical Systems Operation, Milwaukee, Wisconsin. 4 figures, 1 table.
Date: January 1, 1982
Creator: Maylotte, D. H.; Kosky, P. G.; Spiro, C. L. & Lamby, E. J.
Partner: UNT Libraries Government Documents Department

Chemomechanical phenomena in the grinding of coal. Final report, February 1, 1976--May 31, 1977

Description: Vickers microhardness, drilling rate, grinding rate and zeta-potential measurements have been made on coals of various rank in both aqueous and organic environments in order to determine whether: (a) chemomechanical (Rebinder) effects exist in coal; and (b) any such effects as do exist can be used to improve the comminution of coal. The results reveal the mechanical behavior of coal to be remarkably environment-insensitive as compared to inorganic non-metals. As a result, it is concluded that chemomechanical phenomena offer little prospect of reducing the cost of comminuting coal.
Date: August 1, 1977
Creator: Macmillan, N.H.
Partner: UNT Libraries Government Documents Department

Establishment and maintenance of a coal sample bank and data base. [Including sample preparation without oxidation]

Description: Retrieval of 5-lb splits of -1/4 inch coal from designated 30-gallon drums was completed. Preparation and analysis of these samples for the second yearly quality evaluation is in progress. After consultation with the DOE Project Manager, two replacement samples were collected. These are the first of the series which will be stored in foil laminate bags. Both of these samples were placed in 30 gallon steel drums lined with polyethylene bags at the mine site. They were equipped with lid gaskets made from Tygon tubing, and 1/4 in. metal tubing fittings to purge and pressurize the drum with argon.
Date: January 19, 1990
Creator: Davis, A.
Partner: UNT Libraries Government Documents Department

Small-angle x-ray scattering studies of the porosity of coals and chars. Quarterly progress report, July 1-September 30, 1980

Description: Considerable effort has been devoted to checking and verifying some of the preliminary data reported previously. The technique employed in the past for measuring the x-ray transmission of the samples has been modified to provide more accurate values of the transmission. These transmission measurements are important for quantitative interpretation of the scattering data both because they are needed to determine the amount of background scattering that must be subtracted from a measured scattering curve and also because the value of the transmission is required for calculating the specific surface from the scattering data. Previous determinations of the specific surface have been checked and modified when corrected transmission values made recalculation necessary. Evaluation of the specific surface from the scattering data also requires a measurement of the absolute scattered intensity, or scattering cross section. In other words, the fraction of the incident radiation which is scattered must be known. For this scattering investigation of coals, the absolute intensity for the scattering system was determined by measurement of the scattering from a colloidal silica suspension. The details of this technique are described by I.S. Patel and P.W. Schmidt, J. Appl. Cryst. 4, 50 to 55. (1971).
Date: September 1, 1980
Creator: Schmidt, P.W.
Partner: UNT Libraries Government Documents Department

Structure and chemistry of coals: calorimetric analyses. [Wetting heat]

Description: Heats of immersion (h/sub i/) of coals have been shown to be a valuable means of investigating structure and chemistry of coals. This report outlines some of the factors involved. Lower ranked coals imbibe more liquids (i.e., H/sub 2/O) onto more polar sites (carbonyl, phenolic, etc.) than higher ranked coals. Mineral matter reacts strongly with polar liquids (i.e., H/sub 2/O) giving rise to enhanced h/sub i/. Grinding of coals not only decreases particle size but modifies the coal structure to an increasing degree dependent upon the extent and severity of grinding. The magnitude of h/sub i/ and the rate of reaction are both modified consistent with the existence of a shrinking core or unperturbed coal structure serving as substrate to which the modified (less ordered) material is bound. Chemical (alkali) attack seems to loosen the coal structure markedly to allow enhanced access to fluid reagents. These exploratory studies have shown that calorimetric analyses similar to those developed and used by A.C. Zettlemoyer and his coworkers are excellent means for elucidating the structure and chemistry of coals and related materials.
Date: January 1, 1979
Creator: ,
Partner: UNT Libraries Government Documents Department

A novel method of atomizing coal-water slurry fuels

Description: Despite the body of work describing the performance of effervescent atomizers, its potential for use with coal water slurries (CWS) had not been evaluated prior to this study. This program was therefore undertaken: to demonstrate that effervescent atomization can produce CWS sprays with mean drop sizes below 50{mu}m; to determine a lower size limit for effervescent atomizer produced CWS sprays; to determine the mechanism(s) responsible for the formation of effervescent atomizer produced sprays. An analysis of the effects of slurry rheological properties (as indicated by the consistency index and the flow behavior index) and formulation (in terms of loading and coal particle top size) on the spray formation process was performed. The experimental data reported were then analyzed to explain the physical processes responsible for spray formation. The analysis began by considering an energy balance across a control volume that extended from the nozzle exit plant to the line of spray measurement. The inlet conditions were calculated using two-phase flow techniques and the outlet conditions were calculated by using conservation of momentum and assuming that the final velocities of the air and liquid were equal. Entrainment was considered negligible and losses were accounted for by realizing that only a small fraction of the atomizing air participated in the spray formation process with the remainder passing through the control volume unperturbed. Results are discussed. 41 figs., 4 tabs.
Date: May 1, 1990
Creator: Sojka, P.E. & Lefebvre, A.H.
Partner: UNT Libraries Government Documents Department

Configurational diffusion of coal macromolecules

Description: The objective of this project is to investigate the phenomenon of hindered diffusion of coal macromolecules in idealized porous media. Tasks towards this objective include: Construct a diffusion cell with ideal pore structure for determination of diffusion coefficients, prepare and characterize ideal porous membranes, perform model compound experiments to calibrate and test diffusion apparatus and methodology, prepare and characterize coal macromolecules, and analyze data to evaluate the diffusional behavior of coal macromolecules. This report describes work on the hindered diffusion of tetraphenylporphine and asphaltene. 18 refs., 3 figs., 4 tabs.
Date: January 1, 1990
Creator: Guin, J.A.; Curtis, C.W. & Tarrer, A.R.
Partner: UNT Libraries Government Documents Department

Correlation of stability/rheology relationship with coal properties and chemical additives

Description: The overall objective of this project is to perform experiments to evaluate the necessary boundary conditions in the preparation and utilization of Coal Water Slurries (CWS) and also develop a data base for the conceptual analysis of a prescription to predict slurry quality for a given coal candidate. This quarter, zeta potential and static stability measurements of three coal slurries have been made using poly naphthalene ammonium sulphonate, A-23, A-23S MCG-32A-LS and Igepal 990 as dispersants and at a pH of 10. A preliminary study of the static stability measurements were made in a column having two outlet ports separated by a distance of 1 ft. Samples were withdrawn periodically from these ports and the solid content profile was determined for an initial period of one week. Based on the results obtained from this preliminary study, larger samples were prepared and the stability measurements made in a 6 ft column having three outlet ports with a water jacket surrounding it. Zeta Potential measurements were made prior to the stability studies. 1 tab.
Date: January 1, 1990
Creator: Ohene, F.
Partner: UNT Libraries Government Documents Department

Correlation of stability/rheology relationship with coal properties and chemical additives

Description: A methodology has been developed in order to determine the influence of individual particle size fractions on coal water slurry rheology. This involves the determination of the packaging concentrations and rheology of the separate particle size fractions; {minus}400 mesh, {minus}400/325, {minus}325/270, {minus}270/200 mesh, {minus}200/140 mesh, {minus}140/100 mesh and {minus}100/80 mesh as a function of solids loading. The packaging concentrations of the separate particle size fractions and that of several blends of these sizes have been determined. The packaging concentrations were determined from particle size distribution measurements and a program based on truncated log-normal distribution which has been developed at the Adelphi Center for Energy Studies. 5 refs., 7 figs., 10 tabs.
Date: January 1, 1990
Creator: Ohene, F.
Partner: UNT Libraries Government Documents Department

Occurrence of detrital mineral matter in Okefenokee peats

Description: Peat, the precursor of coal, is predominantly composed of partially decomposed plant debris along with varying amounts of inorganic material. This inorganic matter (often referred to as ash) consists of a mixture of distinct mineral species and ionically-bound or complexed inorganic compounds. The composition of this inorganic fraction is controlled by a variety of botanical and depositional environments and processes. The peats used in this study are from the Okefenokee Swamp, a low-sulfur, exclusively fresh water analog of an ancient coal-forming environment. Unlike other peat deposits, the inorganic fraction of Okefenokee peats is primarily composed of silica, most of which consists of biologically-derived, authigenic particles. However, the peats do contain non-biogenic mineral particles of both a silica and non-silica composition. The purpose of this project was to determine grain textures and elemental compositions of the non-biogenic particles through use of scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) analysis. Analytical results indicate that many of these mineral particles are detrital in origin.
Date: January 1, 1983
Creator: Andrejko, M.J. & Raymond, R. Jr.
Partner: UNT Libraries Government Documents Department

Studies of coal reactivity for direct liquefaction

Description: This paper presents a preliminary report on a continuing effort to quantify the reactivity of coal for direct liquefaction reactions in terms of the utilization of hydrogen, the selectivity to products and the properties of the products formed. Liquefaction processes are aimed at maximizing the yield of distillate that can serve as hydrocarbon fuels and chemical feedstocks. This study seeks to better describe: (1) how hydrogen consumed during liquefaction is distributed among product groups; (2) coal reactivity in terms of a relationship defining the selectivity to products formed during liquefaction; and (3) the relation of coal structure to reactivity for liquefaction reactions. Because of the limited space for reporting this effort in this special edition of Fuel, the experimental methods, calculations and data are presented in abbreviated form in order to focus on interpretation and discussion of the results in terms of coal structure and reactivity. 30 refs., 3 figs., 2 tabs.
Date: January 1, 1990
Creator: Stephens, H.P. & Kottenstette, R.J.
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

Coal repository. Final report

Description: The Coal Repository Project was initiated in 1980 by the Department of Energy/Pittsburgh Energy Technology Center to provide a centralized system for the collection of well characterized coal samples, and distribution to organizations involved in the chemical beneficiation of coal and related research. TRW Energy Development Group, together with its subcontractor Commercial Testing and Engineering Company, established the Coal Repository at the TRW Capistrano Chemical Facility, which is the location of the DOE-owned Multi-Use Fuel and Energy Processes Test Plant (MEP). Twenty tons each of three coals (Illinois No. 6, Kentucky No. 11 (West), and Pittsburgh No. 8 (from an Ohio mine)) were collected, characterized, and stored under a nitrogen atmosphere. Ten tons of each coal are 3/8-inch x 0, five tons of each are 14-mesh x 0, and five tons of each are 100-mesh x 0. Although TRW was within budget and on schedule, Department of Energy funding priorities in this area were altered such that the project was terminated prior to completion of the original scope of work. 9 figures, 3 tables.
Date: November 1, 1983
Partner: UNT Libraries Government Documents Department

Determination of the effect of various hydrogen bonding functionalities on the viscosity of coal liquids

Description: The objective of this program was to differentiate and quantitate the effects of various hydrogen bonding functionalities on the viscosity of coal liquids. Emphasis was on separating and measuring the individual effect of phenolic (acidic) and aromatic amino (basic) hydrogen bonding functionalities on the viscosity of coal liquids. The elimination of both acidic and basic hydrogen bondings was attempted by using trifluoroacetyl chloride and butyric acid in derivatization; and the elimination of basic hydrogen bondings was attempted by using only trifluoroacetyl chloride in derivatization. The selectivity toward hydrogen bondings' elimination offered by these derivatizations was proven to be feasible from a study of model compounds' derivatizations. Nine narrow-boiling-range coal distillates were obtained from distilling the coal liquids of Wilsonville Run 245 and were used as coal liquid samples. 6 figs.
Date: November 15, 1990
Creator: Wei, Jing-Fong.
Partner: UNT Libraries Government Documents Department

Development and evaluation of supercritical fluid chromatography/mass spectrometry for polar and high-molecular-weight coal components. Technical progress report

Description: This Technical Progress Report reviews the technical progress made over the first 18 months of the program. Our goals include the design, development, and evaluation of a combined capillary column supercritical fluid chromatograph/high-performance mass spectrometer capable of analyzing high-molecular-weight polar materials and evaluating the system's potential for application in coal conversion process monitoring. The program includes not only the development and evaluation of the required instrumentation, but the development of polar fluids and compatible chromatographic stationary phases needed for efficient separation and analysis of polar and high-molecular-weight compounds. A new chromatograph/mass spectrometer interface and new mass spectrometer ion source have been designed, constructed, and evaluated using low-polarity supercritical fluids such as pentane. Results from the evaluations have been used to modify the instrumentation to improve performance. The design and fabrication of capillary flow restrictors from fused silica tubing has been explored. Research has also been conducted toward advancing the technology of fabricating high-performance chromatographic columns suitable for use with polar supercritical fluids. Results to date support our initial belief that high-resolution supercritical fluid chromatography (SFC)/high-performance mass spectrometry (MS) will provide a significantly enhanced analytical capability for broad classes of previously intractable fuel components. 10 refs., 13 figs.
Date: January 1, 1986
Creator: Chess, E.K. & Smith, R.D.
Partner: UNT Libraries Government Documents Department