Showing papers on "Coal published in 1968"

Ambient carbon monoxide and its fate in the atmosphere.

Abstract: Carbon monoxide, the most abundant air pollutant found in the atmosphere generally exceeds that of all other pollutants combined (excluding C02). An estimated tonnage of >87 X 106 of CO was emitted in the United States from major technological sources alone during 1966. More than 90% of the total CO emitted from fossil fuels is derived from gasoline powered motor vehicles. Other sources of CO include emissions from coal and fuel oil burning, aircraft and open burning. Some CO is also formed by certain vegetation and marine invertebrates (siphonophores). Chemical reactions of CO in the upper and lower atmosphere are discussed. Chemical oxidation of CO in the lower atmosphere by molecular oxygen is very slow. The exact duration of CO in the lower atmosphere is not known with certainty; however, the mean residence time has been variously estimated to be between 0.3 and 5.0 years. In the absence of scavenging processes the estimated world-wide CO emission would be sufficient to raise the’atmospheric level by ...

Hydrogenation of Coal and Tar

Abstract: From Abstract: "This bulletin traces the development of high-pressure, coal and tar hydrogenation technology, based on intensive review of the pertinent literature. The bulletin was written as a part of the Bureau of Mines research program on synthetic liquid fuels. It covers the history and economics of the process; the chemical aspect of hydrogenation of coal, tar, and middle oil; the engineer aspect of converting coal and tar to liquid fuels, principally gasoline; and the equipment of the process."

Electrical Resistivity of NiAl, CoAl, NiGa, and CoGa

Abstract: The electrical resistivities of NiAl, CoAl, NiGa, and CoGa were measured at 4.2° and 297°K by the usual potentiometric method. The variations of resistivities of these intermetallic compounds with temperature and composition indicate that the compounds are metallic, although not good conductors, and that the point‐defect concentration present in these materials is important in considerations of the electrical transport properties. The variations of resistivities with composition indicated that the point defects in NiAl, CoAl, and CoGa tend to cluster as the composition departs from stoichiometry.

Hydrogen and carbon monoxide from slurries of solid carboniferous fuels

Abstract: Production of synthesis gas from a slurry of particulate solid carboniferous fuels, e.g., petroleum coke, coke from bituminous coal, coal, oil shale, tar sands, pitch, or mixtures of these materials in water or in a hydrocarbon liquid fuel. The amount of particulate solid carboniferous fuel in a pumpable slurry may be increased to 75 wt. percent and the particle size of the solid fuel may be increased to pass through a 12 mesh screen by the addition of 2 to 10 wt. percent of soot as produced, for example, by the partial oxidation of crude oil. The slurry at a relatively low velocity in the range of 5 to 50 feet per second is mixed with a stream of oxidizing gas at a relatively high velocity in the range of 200 feet per second to sonic velocity at the burner tip to form an atomized dispersion of water, hydrocarbon liquid fuel, oxidizing gas, and solid carboniferous fuel. Under synthesis gas-generating conditions, the atomized dispersion is reacted to produce a gaseous mixture of hydrogen and carbon monoxide. By this process, pumpable slurry feeds of low-cost solid carboniferous fuels may be gasified in a synthesis gas generator without being preheated.

Direct reduction of iron ore

Abstract: An apparatus and process for the direct reduction of iron ore to steel or high grade iron and the recovery of heat therefrom wherein pulverized coal or other carbonaceous material and oxygen or air are introduced into the upper annular portion of a reactor in a direction tangential to an imaginary circle in the annular portion so as to create a reducing atmosphere of the proper composition and temperature. Pulverized iron ore, fluxing materials and any required additional coal and oxygen are then added, also tangentially, to the reactor at a lower elevation so as to be intimately mixed. The iron ore is reduced in suspension and the molten iron or steel is tapped from the bottom of the reactor. The gaseous products of the reduction reaction are withdrawn from the reactor up through a duct which extends down through the center of the reactor and then passed to a waste heat boiler in which sensible and chemical heat are recovered.

Laser Heating of Coal Particles in the Source of “Time-of-Flight” Mass Spectrometer

Abstract: DURING general investigation of the processes that occur in the combustion of pulverized coal, experiments have been undertaken to develop methods for determining the nature of products formed by the rapid thermal decomposition of coal particles, especially those evolved in the very early stages of decomposition. In previous work1 the yields of the stable decomposition products evolved from small coal particles during the first millisecond of flash heating were determined by quenching the products in an inert atmosphere. Using this method, however, it was not possible to determine whether free radical fragments constituted part of the primarily evolved species. Recent work on the pyrolysis of lump coal using a laser beam has suggested that free radicals of molecular weight of about 100 are evolved2, but in these experiments the products arose both from complete vaporization within the crater formed by the direct beam and from relatively slow low-temperature pyrolysis around this crater.

Availability of Nitrogen to Plants in Acid Coal Mine Spoils

Abstract: MINING of coal by either strip (open cast) or deep-mining methods leaves large quantities of raw rock overburden and waste on the surface and revegetation of such spoils presents great reclamation problems. Survival and growth of plants are hampered by a variety of physical and chemical features of the spoils; in particular, poor growth has been attributed to lack of plant nutrients, especially nitrogen. Nevertheless, investigations of anthracite coal mine spoils in the vicinity of Tamaqua, Pennsylvania, showed that the nitrogen available to plants may be very abundant in certain spoils composed of black pyritiferous shales.

Process for treating coal

Abstract: 1285661 Solvent extraction of coal UNIVERSAL OIL PRODUCTS CO 12 Jan 1970 1376/70 Heading C5E In a process for obtaining liquid hydrocarbons from solid particulate coal by counter-current solvent extraction, preferably in the presence of hydrogen, a hydrogen-donor type coal solvent is introduced at a plurality of vertically spaced points at the lower end of a vertically disposed zone down which crushed coal is passed. Temperatures and pressures in the zone may vary from low elevated up to 500‹ C. and 10,000 p.s.i.g. and the coal may be slurried with the solvent before entering the zone. Solvents mentioned include hydrocarbon mixtures, e.g. obtained from the process by subsequent treatments, and Tetralin, Decalin, biphenyl and (di)- methyl-naphthalene, and an anti-solvent may be included, e.g. hexane. A hydrogenation catalyst may be supplied to the zone either separately or mixed with the coal or solvent. The process is preferably applied to bituminous coals, but sub-bituminous coals and lignites may be used. Typical products are gasolines and fuel oils.

Metal and Mineral Concentrations in Lungs of Bituminous Coal Miners

Abstract: The concentrations of metals and minerals in lungs of bituminous coal miners are the subject of a continuing study that includes gravimetric determinations of coal and total dust, chemical determinations of free silica, and quantitative spectrographic analyses of metallic and other elemental constituents. The free silica and the elemental constituents of the residual mineral deposits were determined by phosphoric acid and quantitative emission spectrographic methods, respectively.

Hydrogen Cyanide Produced from Coal and Ammonia

Abstract: Hydrogen c y a n i d e (HCN) h a s been one of t h e c o u n t r y ' s s t r o n g e s t growth pe t rochemica ls i n r e c e n t y e a r s . U . S . p r o d u c t i o n h a s i n c r e a s e d from 174 m i l l i o n pounds i n 1960 to 350 m i l l i o n pounds i n 1964, a 1 0 0 p e r c e n t i n c r e a s e over t h e 4-year p e r i o d . The growth of p r o d u c t i o n of hydrogen c y a n i d e h a s been d i r e c t l y ' r e l a t e d t o t h e e x p a n s i o n i n p r o d u c t i o n of s y n t h e t i c t e x t i l e s from a c r y l o n i t r i l e . R e l a t i v e growth and p r o d u c t i o n of hydrogen c y a n i d e and a c r y l o n i t r i l e i s a s f o l l o w s :.

Stripping-coal resources of the United States

Abstract: The amount of coal mined and potentially minable by strip-mining methods has increased steadily throughout the years, concomitantly with an impressive increase in the size and efficiency of strip-mining machinery. An analysis by States of the geologic and technologic sources of information on stripping coal indicates that as of January 1, 1970, the remaining recoverable resources of stripping coal in the United States in the 0to 150-foot-thick overburden category totaled 128 billion tons. This figure is 29 times the cumulative stripcoal production from the beginning of mining to January 1, 1970, and it is 690 times the 1969 strip-coal production of about 185 million tons. These convenient simplified comparisons are an aid in appreciating the magnitude of the stripping-coal resources, but they do not represent life expectancy because the rate of production and the estimated size of the resource will surely change in the future. The total estimated recoverable stripping-coal resources are widely distributed in 26 States as tabulated herein, but significantly large amounts are concentrated in (1) Northern Great Plains region of western North Dakota, eastern Montana, and northeastern Wyoming, (2) the Illinois basin, and (3) the north half of the Appalachian basin.

The Sulfur Balance of Incinerators

Abstract: Municipal refuse usually contains only 0.10-0.15% sulfur. During combustion a minor fraction of the sulfur is released as SO2, while the major fraction is fixed in the ash, which contains alkaline oxides. Contrasted with coal and heavy fuel oil, municipal refuse is a minor to negligible source of SO2 air pollution.

Process and system for producing synthetic crude from coal

Abstract: Since the most valuable of the products of the coal treatment process is the synthetic petroleum crude, it is understood that the commercial feasibility of any such process is very largely dependent upon the quality, and hence the value, of the synthetic crude produced. For optimum value, the synthetic crude should be of such a quality that it can be processed in a conventional petroleum refinery, along with petroleum crude, without substantial alteration of operating conditions. It has been suggested, however, that certain superior grades of fuel may be produced from synthetic petroleum crude derived from low temperature carbonization of coal. A method for producing synthetic petroleum crude which is, in its refinery characteristics, substantially identical with high quality petroleum crude, is provided. Specifically, this process relates to methods for producing synthetic petroleum crude by carbonization of coal and hydrotreating of coal tar products. (8 claims)

Apparatus and method for the hydrogenation of coal

Abstract: THE CONVERSION OF COAL TO METHANE BY REACTION THEREOF WITH HYDROGEN GAS AT ELEVATED TEMPERATURES AND PRESSURES IN THE PRESENCE OF A CATALYST IN A GASIFIER APPARATUS WHEREIN THE HYDROGEN GAS REQUIRED IS SUPPLIED BY THE DISSOCIATION OF WATER VAPOR. POWER FOR THE DISSOCIATION IS GENERATED IN A POWER STATION IN WHICH CARBONACEOUS CHAR (WHICH IS A BY-PRODUCT OF THE COAL HYDROGENATION OCCURING IN THE GASIFIER) AND AIR (WHICH MAY, IF DESIRED, BY ENRICHED BY OXYGEN PRODUCED DURING THE DISSOCIATION) ARE BURNED. THE DISSOCIATION IS ACCOMPLISHED IN SOLID OXYGEN-ION ELECTROLYTE CELLS PREFERABLY OPERATING AT TEMPERATURES IN EXCESS OF 800*C.