Showing papers on "Coal published in 1985"
TL;DR: In the Gippsland basin, coniferous rain forests dominated by kauri vegetation flourished in a raised bog setting as mentioned in this paper, which provided large quantities of hydrogen-rich exinite macerals with potential to generate oil.
Abstract: Contrary to the conventional belief that humic coal generates primarily gas, 3 billion bbl of recoverable oil has been discovered in the humic coaly succession of the fluviodeltaic Latrobe Group (Upper Cretaceous-Tertiary) that serves as both the reservoir and the source for hydrocarbons in the offshore Gippsland basin of southeastern Australia. Evidence for generation of liquid hydrocarbons from the coaly succession includes: (1) similarity of n-alkane distribution in the oil and in the coal extracts; (2) high wax content of oil (up to 27% by weight); (3) high ratio of pristane/phytane in oil (5-6); and (4) dominance of C29 steranes in the oil. In the Gippsland basin, coniferous rain forests dominated by kauri vegetation flourished in a raised bog setting. Present temperate climate and kauri vegetation of New Zealand are considered to be the modern analog to the Gippsland basin. The coniferous vegetation provided large quantities of hydrogen-rich exinite macerals, such as cutinite and resinite, with potential to generate oil. High rainfall, raised ground-water level, low oxygen, high acidity, and low-nutrient conditions of a raised bog setting were suitable for preserving organic matter. A comparison of gas chromatograms of oils in the Gippsland basin with gas chromatograms of oils generated by hydrous pyrolysis in the laboratory from the immature source rocks suggests that the paraffinic fraction of the oil was derived from coal, and the naphthenic fraction was derived chiefly from resin.
497 citations
TL;DR: In this article, the effect of coal rank on the gasification rate of coal char was examined and it was concluded that the surface active sites and/or the amount of exchangeable Ca and Na control the reactivity of low-rank coal chars in H2O.
236 citations
Book•
01 Sep 1985
TL;DR: In this paper, the authors present short course notes designed for participants of the 1983 Geological Association of Canada Annual Meeting held in Victoria, British Columbia, May 8-10, 1983.
Abstract: This book consists of short course notes designed for participants of the 1983 Geological Association of Canada Annual Meeting held in Victoria, British Columbia, May 8-10 1983. After a brief introduction and historical overview, the origin of coal and systems of coal rank classification are considered. The petrographic composition of coal covering macerals, lithotypes, mineral matter and trace elements is covered in some detail. Oxidation and weathering are discussed, sampling, sample preparation and petrographic methods are described. The relationship of petrographic properties to other coal properties, and the geological and technological applications form a major part of the course notes.
231 citations
TL;DR: In this article, the authors show that physical depositional environment models for the origin of coal do not adequately explain variations in mineral matter content and composition in commercial quality coal beds in the central Appalachian basin.
226 citations
TL;DR: In this article, three coals, two lignites from the Beulah mine, North Dakota and the Bryan mine, Texas and one subbituminous coal from the Rosebud mine, Montana, were analyzed for inorganic materials.
Abstract: Three coals, two lignites from the Beulah mine, North Dakota, and the Bryan mine, Texas and one subbituminous coal from the Rosebud mine, Montana, were analyzed for inorganic materials. A flowsheet is presented to show the procedure used. Each coal was ground to approximately 400 mesh in an alumina grinding apparatus. The ground coal was dried using a freeze drier. Analysis of the dried coal was performed using x-ray fluorescence (XRF) and neutron activation analysis (NAA). Duplicate samples were run by placing 15 to 20 g of coal in a plastic beaker with 100 ml of 1M ammonium acetate. This was heated to about 70/sup 0/C and stirred for 20 hours. The sample was filtered, the residue washed and dried. The solution was transferred to a 500 ml volumetric flask and made up to volume. The solution was analyzed by inductively coupled argon plasma spectroscopy (ICAP). Samples of the residue were analyzed by XRF and NAA. The residue was treated a second time with ammonium acetate followed by two 1M hydrochloric acid extractions using the same procedure as ammonium acetate extraction. The alkaline and alkaline earth metals in all three coals are partially or totally removed with ammonium acetate extraction.more » The major differences between the coals are: (1) 48% of the total inorganics of the Beulah are removed with ammonium acetate by far the highest of 3 coals. (2) Bryan Texas lignite consists of mostly extraneous mineral matter including clays and quartz minerals. (3) Rosebud subbtuminous has higher percentages of Mg, Ca, and Sr associated as carbonates, revealed in the HCl extractions. 1 figure, 3 tables.« less
201 citations
TL;DR: The low-temperature oxidation of five coals, ranging in rank from subbituminous to anthracite, was studied in the temperature range 30 −250 °C, and the reaction kinetics were elucidated as discussed by the authors.
117 citations
TL;DR: In this paper, a one-dimensional model was developed to describe the spontaneous heating process at relatively low temperatures of coal piles, and the model was applied to coal piles in coal fires.
111 citations
TL;DR: In this paper, the reduction of nitric oxide during combustion of coal char in a fluidized-bed combustor was examined with respect to two reactions: a char-catalysed reaction and a charconsuming reaction.
108 citations
TL;DR: The mode of occurrence and concentration of trace elements in bituminous and sub-bituminous coals have been examined in terms of chemical characteristics of the coal substance and mineral matter as mentioned in this paper.
TL;DR: In this article, the distribution of sodium in different sizes of fly ash produced during coal combustion provides useful insights into the vaporization and condensation mechanisms for sodium, and the departure of the concentration of sodium from an inverse square dependence on particle size can be used to infer the degree of sodium vaporization.
01 Jan 1985
TL;DR: In this article, the rate of gasification and the reactivity of the char surface are considered to be more closely controlled by the chemical properties of the surface than by its composition, mineral content, and pore structure.
Abstract: Chars from coals of fuel ratio 1 to 8 were gasified with a CO/sub 2/ - N/sub 2/ mixture at atmospheric pressure. At 1,000/sup 0/ C or less, when the reaction is controlling, the rate of gasification is dependent on the type of coal, and the reactivity is minimal at a fuel ratio (fixed carbon/volatile matter) of about 3. The fractional gasification f and the dimensionless gasification time, when normalized by the time to reach f = 0.5, are correlated by a single curve for all chars, based on a modified volumetric model for the reaction. The rate of gasification and the reactivity of the char are considered to be more closely controlled by the chemical properties of the char surface than by its composition, mineral content, and pore structure.
TL;DR: INAA results showed that the fly ash between about 0.5 and 8 m was fairly uniform in composition and that the micrometer fume composition was quite different, and the fume was highly enriched in volatile elements such as Ga, As, Sb and Se and depleted in refractory elementssuch as Al, Hf and Sc.
Abstract: Total and elemental mass size distributions from about 10 to 0.04 m were obtained for the fly ash aerosol at the outlet of a pulverised coal utility boiler and upstream of the particulate control device. Elemental data were obtained by instrumental neutron activation analysis and X-ray fluorescence analysis of cascade impactor samples. Submicrometer measurements were also made with an electrical aerosol analyser. INAA results showed that the fly ash between about 0.5 and 8 m was fairly uniform in composition and that the micrometer fume composition was quite different. The fume was highly enriched in volatile elements such as Ga, As, Sb and Se and depleted in refractory elements such as Al, Hf and Sc.
01 Jan 1985
TL;DR: In this paper, a historical review of coal and coal-bearing sequences of North America is presented, including coal-depositional models of modern peats and applications of coal depositional models to mining problems.
Abstract: Outline of Contents: Sedimentology of coal and coal-bearing sequences of North America: a historical review General coal depositional models Depositional models of modern peats Applications of coal depositional models to mining problems Coal composition and depostional environments Sedimentary tectonics of coal basins.
TL;DR: In this article, the isosteric heat of adsorption of CH 4 indicated that the coal surface became more heterogeneous on carbonization, but the increase was not entirely associated with the increase in surface area.
TL;DR: In this article, a detailed phenomenological study of the gasification behavior of a North Dakota lignite was undertaken and the fundamental parameters that determine char reactivity were investigated by varying the conditions of coal pretreatment and pyrolysis, and the observed reactivity differences were rationalized in terms of variations in the concentration of carbon and catalyst active sites.
TL;DR: In this article, the authors describe and test the use of a thermogravimetric technique for measuring the ignition temperatures of thin layers and beds of coal particles, and report the results of such measurements on a South African coal, a Polish coal and two chars.
Abstract: In this paper we describe and test the use of a thermogravimetric technique for measuring the ignition temperatures of thin layers and beds of coal particles, and we report the results of such measurements on a South African coal, a Polish coal and two chars. The technique is to compare weight-temperature curves in air and inert (N2) atmospheres in order to evaluate the ignition temperature; the results are used to test the existing theory and to obtain kinetic constants for the reactions.
TL;DR: In this paper, the main factors influencing reactivity of char originating from coal and lignite against different gasifying agents are reviewed, taking typical examples given in literature, the role of coal minerals, the effect of pyrolysis conditions, importance of the internal surfaces and their quality and accessibility are assessed.
TL;DR: CARS measurements in a coal fired boiler are presented in an investigation of their applicability to industrial burners.
Abstract: CARS measurements in a coal fired boiler are presented in an investigation of their applicability to industrial burners.
TL;DR: In this article, surface area measurements and morphology studies on two size-fractionated samples of coal fly ash were performed and it was shown that small ash particles are predominantly non-porous spheres with irregular surface morphology.
Abstract: Results of surface area measurements and morphology studies on 2 size-fractionated samples of coal fly ash show that small ash particles are predominantly non-porous spheres with irregular surface morphology. For the sample taken from a particle collector, it is shown that large surface areas are attributable to carbonaceous particles of highly porous character. It is suggested that the surface area of particles in a coal-fired power plant depends on the point of collection.
TL;DR: In this article, the influence of intraparticle mass and heat transfer phenomena on the overall rate and product yields during coal particle devolatilization in an inert atmosphere is investigated.
Abstract: The objective of the present work is to elucidate the influence of intraparticle mass and heat transfer phenomena on the overall rate and product yields during devolatilization of a single coal particle in an inert atmosphere. To this end a mathematical model has been formulated which covers transient devolatilization kinetics and intraparticle mass and heat transport. Secondary deposition reactions of tarry volatiles also are included. These specific features of the model allow a quantitative assessment to be made of the impact of major process conditions such as the coal particle size, the ambient pressure and the heating rate on the tar, gas and total volatile yield during devolatilization. Model predictions are compared to a limited number of experimental results, both from the present work and from various literature sources.
TL;DR: The preservation of cell contents, plant apices, gametophytes, etc., demonstrates the contemporaneous or early diagenetic formation of coal balls, which supported arguments for a marine source for the carbonate.
Abstract: Coal balls (exceptionally preserved calcareous permineralized peat), widely described from tropical Carboniferous Euramerian coal seams, have yielded diverse data on the biology, ontogeny and ecology of swamp plants and ecosystems. Probably over 75% of the swamp taxa may have been preserved, in contrast to probably less then 10% in other contemporaneous environments, but the assemblages are species-poor and represent an evolutionarily conservative assemblage. The in situ nature of coal ball peats allows ecological changes to be identified from vertical profiles. Major changes in plant communities both within individual seams and between seams appear to reflect both local and widespread climatic changes, particularly in rainfall. The preservation of cell contents, plant apices, gametophytes, etc., demonstrates the contemporaneous or early diagenetic formation of coal balls. Their common association with marine sediments has supported arguments for a marine source for the carbonate. Stable oxygen and carbon isotope studies suggest a meteoric origin for some carbonate. No current model for the formation of coal balls completely explains their occurrence and rarity outside the Upper Carboniferous of Eurameria.
Patent•
25 Jun 1985TL;DR: In this paper, raw materials such as glass batch are preheated by combustion of liquid or solid fuel such as fuel oil or coal mixed with the batch material and any ash from the fuel are transferred to a second stage where they are liquefied.
Abstract: Raw materials such as glass batch are preheated by combustion of liquid or solid fuel such as fuel oil or coal mixed with the batch material. In one embodiment the material being heated and the gaseous products of combustion are passed cocurrently through the preheating stage to avoid carbonaceous effluents. Preheated materials and any ash from the fuel are transferred to a second stage where they are liquefied. Carbon monoxide from the preheating stage may serve as fuel for the liquefying stage.
TL;DR: In this paper, a batchwise fluidized bed combustion of a coal has been carried out to investigate the generation of elutriable carbon fines by attrition of the burning char.
Abstract: Batchwise fluidized bed combustion of a coal has been carried out to investigate the generation of elutriable carbon fines by attrition of the burning char, Differences between the purely mechanical attrition and the combustion-assisted attrition of the char have been outlined. The time required to “activate” the char surface as regards attrition explains certain features of carbon elutriation curves. Attrition rate constants determined from these curves are compared with those previously found by continuous fluidized combustion of the same coal.
Patent•
25 Jun 1985TL;DR: In this paper, a glass batch is liquefied using a solid carbonaceous fuel such as coal as the major energy source, and the mixture of liquid or solid fuel is mixed with the batch material being fed to an initial liquefaction stage.
Abstract: Thermally fusible material such as glass batch is liquefied using a solid carbonaceous fuel such as coal as the major energy source. In another embodiment, solid or liquid fuel is mixed with the batch material being fed to an initial liquefaction stage. Melting may be advanced further in a subsequent stage where the melt may also be re-oxidized.
TL;DR: The kinetics of microbial leaching ofPyritic sulfur from coal was investigated and the rate of leaching was found to be first order with respect to pyritic sulfur concentration in the reaction medium.
Abstract: More than 90% of initial pyritic sulfur was removed from bituminous coal samples (containing 2.1% pyritic sulfur) using the thermophilic organism Sulfolobus acidocaldarius. Microbial desulfurization rate was improved nearly ten fold by adjusting the N/P and N/Mg ratios in the nutrient medium. Environmental conditions were optimized. The optimal values of temperature and pH were 70 degrees C and 1.5, respectively. The influence of certain process variables (such as coal pulp density, particle size, and initial cell number density) on the rate of pyritic sulfur removal were determined. A pulp density of 20%, particle size of D (p) < 48 microm, and an initial cell number density of 10(12) cells/g pyrite in coal were found to be optimal. The carbon dioxide enriched air did not improve the rate of pyritic sulfur removal compared to pure air at 10% pulp density of coal samples containing 2.1% pyritic sulfur. The kinetics of microbial leaching of pyritic sulfur from coal was investigated. The rate of leaching was found to be first order with respect to pyritic sulfur concentration in the reaction medium.
TL;DR: A coal product which exceeds the purity requirements for ash, iron and silicon in Hall Cell anode carbon was prepared by a unique leaching sequence involving caustic treatment, followed by treatments with sulphuric and nitric acids.
TL;DR: In this paper, the optical anisotropy of solvent-swollen and chemically derivatized thin sections of coal was examined for determining whether the coal is in a plastic or rubbery state, whether a rubber state is cross-linked and how mobile the macromolecular chain segments are.