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Showing papers on "Coal published in 1970"


Journal ArticleDOI
20 Feb 1970-Science
TL;DR: The rate-determining step in the oxidation of iron pyrite and the formation of acidity in streams associated with coal and copper mines isThe oxidation of ferrous iron, and effective pollution abatement necessitates control ling this reaction.
Abstract: The rate-determining step in the oxidation of iron pyrite and the formation of acidity in streams associated with coal and copper mines is the oxidation of ferrous iron. Effective pollution abatement necessitates control ling this reaction.

1,655 citations


Journal ArticleDOI
TL;DR: In this article, the authors found significant differences in the lead isotope ratios in rock and soil, grasses, tree leaves and tree rings, air particulate, and in some industrial products such as coal, fly ash, gasoline, and fuel oil.
Abstract: The object of this research was to determine if the isotope ratios of lead were significantly different in various environmental media and if such differences could be used to distinguish the lead in the media. Significant differences in the lead isotopic ratios in rock and soils, grasses, tree leaves and tree rings, air particulate, and in some industrial products such as coal, fly ash, gasoline, and fuel oil have been found. Leaf, grass, and soil samples taken across the New Jersey Turnpike showed a change in lead isotopic ratios from the Turnpike to a point one mile to windward. The mean value of the Pb-206/Pb-204 ratio in topsoil within 500 feet of the Turnpike was 18.2 +/- 0.2 and beyond 500 feet was 18.7 +/- 0.15. Lead sampled from soil profiles in two forested locations in northern New Jersey showed an increase in Pb-206/Pb-204 ratios, with depth from 18.7 to 19.9 in a 30-inch profile. The lead abundance decreased from 47.5 to 12.0 ppm. The mean ratios of Pb-206/Pb-204 from coal and gasoline analyzed were found to be 18.8 +/- 0.2 and 18.3 +/- 0.3, respectively. The mean value for the same ratio in the published data on coal ismore » somewhat higher. Fly ash and the coal from which it came both contained lead of the same isotopic ratio. 8 references, 12 figures, 3 tables.« less

178 citations


Journal ArticleDOI
TL;DR: The natural deuterium content of organically bound hydrogen shows systematic variations that depend on the origin of the samples as mentioned in this paper, and the hydrogen of both marine and land plants contains several percent less deutricity than the water on which the plants grew.

123 citations


Journal ArticleDOI
TL;DR: In this article, the surface reaction rate of coal chars was measured for a range of eleven coals, high rank and low rank, swelling and nonswelling, using a luminar flow furnace technique described in an earlier paper.

121 citations


Journal ArticleDOI
01 Jul 1970-Fuel
TL;DR: In this paper, two techniques have been used to study the diffusion of methane in American coal of rank varying from low volatile matter anthracite to high volatile content bituminous.

103 citations


Journal ArticleDOI
TL;DR: It is concluded that oxidation and Kjeldahl techniques are unsuitable for organic matter determinations in coal-bearing sediments and that protein estimation provides a useful alternative.

61 citations


Patent
12 Aug 1970
TL;DR: In this article, a process for dissolving bituminous coal by heating a mixture of coal, a hydrogen donor oil, carbon monoxide, water, and an alkali metal hydroxide or its precursor at a temperature of about 400*-450* C. and under a total pressure of at least about 4,000 p.i.s.
Abstract: Process for dissolving bituminous coal by heating a mixture of said coal, a hydrogen donor oil, carbon monoxide, water, and an alkali metal hydroxide or its precursor at a temperature of about 400*-450* C. and under a total pressure of at least about 4,000 p.s.i.g.

52 citations


Patent
23 Jul 1970
TL;DR: In this article, the authors present a method to recover VOLATILE HYDROCARBONS and HYDROGEN by heating the particULAR COAL in a TRANSPORT REACTOR.
Abstract: THIS INVENTION DISCLOSES AN EFFICIENT ECONOMICAL CONTINUOUS METHOD OF PYROLYSING AND DESULRURIZING AGGLOMERATIVE BITUMINOUS COAL IN A TRANSPORT REACTOR TO RECOVER VOLATILE HYDROCARBONS AND HYDROGEN BY HEATING THE PARTICULAR COAL AND CHAR HAVING PARTICLE SIZES OF LESS THAN 65 MICRONS ENTRAINED IN AN INERT CARRIER GAS HAVING PYROLYSIS REACTOR RESIDENCE TIMES OF UNDER THREE SECONDS

50 citations


Patent
Jack W Roach1
09 Jan 1970
TL;DR: In this paper, the authors proposed a method of separating finely divided insoluble material from products of coal liquefaction present in a solvent comprising a heavy organic coal-liquefaction solvent.
Abstract: Coal liquefaction products are separated into a plurality of fractions of varying softening points and molecular complexity in a solvent mixture containing a heavy organic coal liquefaction solvent and a light organic fractionating solvent having a critical temperature below 800* F. under elevated temperature and pressure conditions. In one variant, coal is liquefied with a heavy organic coal liquefaction solvent, the light organic fractionating solvent is added to the solution thus produced, and thereafter the coal liquefaction products are separated into a plurality of fractions at elevated temperature and pressure. Preferred heavy organic solvents include anthracene oil, tetralin, catalytic cracker recycle stocks, thermally cracked stocks and lubricating oil aromatic extracts, and preferred light organic solvents include pyridine, benzene and hexane. In a preferred variant, a mixture of the light and heavy organic solvents is recovered directly from the final fractionating stage, the solvent mixture is separated in a solvent separating vessel directly into a heavy organic solvent phase and a light organic solvent phase, and the two solvent phases are passed in heat exchange relationship with incoming solvent-rich streams to preceding fractionating stages to recover the heat content and produce cooled liquid heavy and light organic solvent streams for recycle. The invention further provides a method of separating finely divided insoluble material from products of coal liquefaction present in a solvent comprising a heavy organic coal liquefaction solvent.

43 citations


Patent
16 Apr 1970
TL;DR: In this article, a steam turbine at a rate that enables it to operate at substantially full capacity continuously is used to produce liquid oxygen in excess of the oxygen requirements of the gas producer and furnace during reduced load period.
Abstract: Oxygen is delivered to a gas producer to gasify coal to produce fuel which is then delivered with more oxygen to a boiler furnace to generate steam and to form products of combustion that include water vapor and carbon dioxide. The water vapor is condensed and separated from the carbon dioxide. The steam is conducted to a steam turbine at a rate that enables it to operate the plant at substantially full capacity continuously. The turbine drives an electric generator. During periods of reduced load, surplus power from the plant is used for liquefying some of the separated carbon dioxide. Some of the surplus power also is used for operating air separation apparatus, to which the liquefied carbon dioxide is conducted to aid in producing liquid oxygen in excess of the oxygen requirements of the gas producer and furnace during the reduced load period. The surplus liquid oxygen is stored for use, after warming, in the plant between the periods of reduced load when the air separation apparatus is not operating.

41 citations


01 Jan 1970
TL;DR: The data presented in this article were assembled to assist in developing a fundamental understanding and a geological perspective of occurrence of coal, petroleum, natural gas, helium, and uranium in Arizona.
Abstract: The data presented in this publication were assembled to assist in developing a fundamental understanding and a geological perspective of occurrence of coal, petroleum, natural gas, helium, and uranium in Arizona. The data are presented in three parts: (1) coals; (2) oil, natural gas, and helium; and (3) uranium. A bibliography is presented at the end of the report. Numerous tables and llustrations are included in each section and in an appendix. (BLM)

Patent
Jack W Roach1
09 Jan 1970
TL;DR: In this article, a method of separating finely divided insoluble material derived from coal during liquefaction thereof from an organic-solvent solution of coal liquefactory products is presented.
Abstract: Coal liquefaction products are separated into a plurality of fractions of varying softening points and molecular complexity by treatment with light organic solvents having critical temperatures below 800* F. under elevated temperature and pressure conditions. In one variant, coal is liquefied employing selected light organic solvents which are suitable for both liquefaction and fractionation, and thereafter the coal liquefaction products are separated into a plurality of fractions by treatment with the solvent contained in the resultant solution. Preferred solvents for liquefying coal include pyridine and benzene, and preferred fractionating solvents include pyridine, benzene and hexane. In a preferred variant, a solvent phase is recovered directly from the final fractionating stage and is passed in heat exchange relationship with solvent-rich streams to preceding fractionating stages to recover the heat content and provide cooled solvent for recycle. The invention further provides a method of separating finely divided insoluble material derived from coal during liquefaction thereof from an organic-solvent solution of coal liquefaction products.

Patent
25 Aug 1970
TL;DR: In this paper, a two-zone system was proposed for coal combustion, where the acceptor material absorbs sulfur in the first zone and releases it in the second zone thus concentrating most of the sulfur oxides in a small fraction of the flue gas.
Abstract: Sulfur-containing fuels such as coal are burned in a two-zone system. Circulating sulfur acceptor material absorbs sulfur in the first zone and releases it in the second zone thus concentrating most of the sulfur oxides in a small fraction of the flue gas.




Patent
13 Apr 1970
TL;DR: A SUB-BITUMINOUS COAL is LIQUEFIED by RAPIDLY HEATING SLURRY of SAID POWDERED COAL in a HYDROGENATED SOLVENT at a TEMPERATURE RANGE of from 440* to 450*C, and a RESIDENCE Time of from about 5 to 20 MINUTES as discussed by the authors.
Abstract: A SUB-BITUMINOUS COAL IS LIQUEFIED BY RAPIDLY HEATING SLURRY OF SAID POWDERED COAL IN A HYDROGENATED SOLVENT AT A TEMPERATURE RANGE OF FROM 440* TO 450*C., AND A RESIDENCE TIME OF FROM ABOUT 5 TO 20 MINUTES.

Journal ArticleDOI
TL;DR: The Carbon Ratio theory as discussed by the authors states that petroleum-type hydrocarbons are formed from precursors which are components of waxy leaf cuticles, pollen and spore coatings, by chemical reactions in which oxygen groups are removed from long chain acids, alcohols and ester waxes.
Abstract: Petroleum hydrocarbons are not normal constituents of recent sediments but only appear when a certain stage of diagenesis is reached, through deeper burial. An investigation of the mechanism of formation of oil and gas has shown that an indication of the generation of oil in a sedimentary basin can be obtained by an examination of coals or coaly material encountered during drilling. Coals form a continuous diagenetic and metamorphic series beginning with peat and ending with graphite. Peat and brown coal contain the same type of hydrocarbons as are present in land plants but the composition of coal hydrocarbons changes abruptly in the sub-bituminous to high-volatile bituminous coal range. This is because petroleum-type hydrocarbons are formed at this stage from precursors which are components of waxy leaf cuticles, pollen and spore coatings, by chemical reactions in which oxygen groups are removed from long-chain acids, alcohols and ester waxes. Most Australian oil occurrences are associated with coal-bearing sediments and it appears likely that they are formed at the same stage of alteration, from such land plant residues, finely disseminated in shales and siltstones. The diagenetic changes in coal composition are caused by the increasing temperature accompanying deeper burial, and the composition of a coal, whatever its present depth, is an indication of the maximum temperature to which it has been subjected. The determination of carbon content, reflectivity and other properties of coal samples provided by a number of oil companies, together with laboratory experiments in which petroleum-type hydrocarbons were generated by artificial diagenesis of coal components, indicated that hydrocarbon generation takes place only when the carbon content of the coals approaches 80 percent. In sedimentary basins in Australia the petroleum generation zone occurs at depths varying from 5,500 to greater than 11,000ft., depending upon present or past geothermal gradient. In addition to this lower limit of diagenesis, it has long been maintained that a relation exists (the Carbon Ratio theory) between the likely occurrence of oil and gas reservoirs in a sedimentary basin and the degree of metamorphism of coal if present. The theory sets an upper limit of alteration of organic matter, and states that oil reservoirs are unlikely to occur in areas or at depths in a basin where the 'fixed-carbon' of the coals is greater than about 65 percent (equivalent to a coal of about 85 percent total carbon — dry, mineral-matter free). The Gid-gealpa-Moomba area appears to be a part of the Cooper Basin in which the organic matter is close to this upper limit of metamorphism. The carbon content of the coal at Gidgealpa, associated with gas and light hydrocarbons, is 85-86 percent whereas that at Moomba, associated with dry gas, is higher at approximately 89 percent. Ihus the properties of coal samples encountered during drilling can provide valuable clues for the petroleum geologist in the search for further oil and gas reserves.

Patent
Jack W Roach1, Leo Garwin1
09 Jan 1970
TL;DR: Coal is solubilized in highly aromatic petroleum byproduct streams such as catalytic cracker recycle oil and slurry oil to produce a coal solution having a low viscosity which is readily deashed by settling and/or filtering as discussed by the authors.
Abstract: Coal is solubilized in highly aromatic petroleum byproduct streams such as catalytic cracker recycle oil and slurry oil to produce a coal solution having a low viscosity which is readily deashed by settling and/or filtering. The coal solution has a low sulfur and mineral ash content and it may be used in the preparation of fuels or as a feedstock to a furnace process for producing carbon black. All or part of the solvent content of the coal solution may be recovered and recycled in the process as a solvent, and the deashed and desulfurized coal thus produced may be used as a solid or molten fuel, or it may be blended with petroleum refinery streams to produce liquid fuels having desired specifications and a feedstock for producing furnace carbon black.

Journal ArticleDOI
01 Jan 1970-Fuel
TL;DR: In this paper, a laser has been used to rapidly heat coals, aromatic compounds, and plastics under high vacuum in a time-of-flight mass spectrometer, and the mass spectra of the products show that these three classes of materials behave quite differently on heating, the type of spectrum produced being characteristic of the structure being heated.

01 Jan 1970
Abstract: This material has been published in Smith, W.H., Nance, R.B., Hopkins, Johnson, R.G., and Shabica, C.W. Depositional environments in parts of the Carbondale formation, western and northern Illinois: Francis Creek Shale and associated strata and Mazon Creek biota, Illinois State Geological Survey Field Guidebook Series, No. 8, p. 61-74, 1970 NOTE: At the time of publication, author Hermann W. Pfefferkorn was affiliated with the Illinois State Geological Survey. Currently (September 2005) he is a faculty member in the Department of Earth and Environmental Science at the University of Pennsylvania.

Patent
03 Aug 1970
TL;DR: In this article, a two-stage process is used to recover heating values from sulfur-containing coal in a two stage process, in which the first stage reacts with CaO in a fluidized bed gasifier to yield CaS and a gas rich in CO. The second stage is a conventional boiler to which the off-gas from the second stage and entrained desulfurized coal fines, are delivered as fuel.
Abstract: Heating values are recovered from sulfur-containing coal in a two-stage process which minimizes pollution. In the first stage, sulfur-containing coal is reacted with CaO in a fluidized bed gasifier which operates adiabatically, under reducing conditions, to yield CaS and a gas rich in CO. The second stage is a conventional boiler to which the off-gas from the first stage and entrained desulfurized coal fines, are delivered as fuel. The flue gas from this boiler contains substantially no sulfur dioxide as a pollutant. CaS is withdrawn from the first stage as a valuable byproduct.


Journal ArticleDOI
01 Oct 1970-Fuel
TL;DR: In this paper, a weakly-caking bituminous coal with benzene/ethanol (7:3 by volume) was extracted, and the total amount of hydrocarbons extracted in 250 h was twice that obtained in 50 h.


Patent
28 Jul 1970
TL;DR: In this paper, a method of treating a fine coal slurry from a coarse coal washing circuit and/or a coal recovery circuit is described, where the slurries are passed to a first frothflotation step to recover a substantial portion of the fine particles of coal therein as a froth product, dewatering the froth products to obtain a cake product containing usable coal and an effluent containing substantially all finely divided coal particles.
Abstract: Improved method of treating a fine coal slurry from a coarse coal washing circuit and/or a slurry from a fine coal recovery circuit wherein the slurries are passed to a first frothflotation step to recover a substantial portion of the fine particles of coal therein as a froth product, dewatering the froth product to obtain a cake product containing usable coal and an effluent containing substantially all finely divided coal particles. The effluent is passed to a second series of frothflotation cells wherein the fine particles of coal are removed as a second froth product and substantially clean water is recovered as the tailings product. The second froth product is returned to the recovery circuit wherein the fine particles of coal are recovered. The tailings product may be recycled if desired.


Patent
09 Jan 1970
TL;DR: In this article, coal is solubilized and hydrogenated in partially hydrogenated hydrocarbon streams such as clarified slurry oil to produce a nonviscous solution which is readily deashed by settling or filtering.
Abstract: Coal is solubilized and hydrogenated in partially hydrogenated hydrocarbon streams such as clarified slurry oil to produce a nonviscous solution which is readily deashed by settling or filtering. Both inorganic sulfur and organically combined sulfur are removed, and the deashed solubilized coal thus produced has a very low sulfur content. The invention is also useful for producing a hydrogenated solubilized coal solution which is suitable for use as a feedstock for a petroleum refinery, and valuable liquid hydrocarbon distillate products boiling, for example, within the gasoline, kerosene, naphtha, light fuel oil and gas oil ranges may be produced therefrom.

Journal ArticleDOI
01 Apr 1970-Fuel
TL;DR: In this paper, a new method for measuring the degree of oxidation of coal has been developed, which appears to be more rapid, simpler, and more generally applicable to coals of widely differing expansion properties.