Showing papers on "Methane published in 1972"
•
30 May 1972TL;DR: In this article, the uppermost layer of the fragmented coal bed is ignited as by injection of oxygen and fuel gas from a surface plant while the product conduits are closed off to raise the operating pressure in the fragmented zone to balance hydrostatic pressure so that the fragmented region comprises effectively a pressurized reaction vessel.
Abstract: Deeply buried relatively thick coal bed formations are fractured explosively. Reactant input conduits communicating with upper portions of the fragmented coal zone and product withdrawal conduits communicating with lower portions thereof are provided. The uppermost layer of the fragmented zone is ignited as by injection of oxygen and fuel gas from a surface plant while the product conduits are closed off to raise the operating pressure in the fragmented zone to balance hydrostatic pressure so that the fragmented zone comprises effectively a pressurized reaction vessel. Water or steam together with regulated amounts of oxygen are then introduced while reaction products are withdrawn at a rate at which operating pressure is maintained so that a relatively higher temperature reaction zone layer is reacted in the upper layer to travel progressively downward. A graduated lower temperature region precedes the higher temperature zone. Various gasification reactions occur in the reaction zones with the net overall products being methane and CO2 with relatively little up to varying amounts of carbon monoxide and hydrogen appearing in the reaction product gas. Processing to remove CO2 and react the carbon monoxide and hydrogen if deemed necessary is done at the surface yielding a high caloric value fuel gas suitable for pipeline or for synthesis uses.
271 citations
••
TL;DR: This chapter explains the description and physiology of one-carbon-utilizing micro-organisms along with their energy metabolism and carbon assimilation, and considers mechanisms that offer a solution to the problem of net biosynthesis from one- carbon units at reduction levels ranging from carbon dioxide to methane.
Abstract: Publisher Summary One-carbon compounds occur abundantly at all oxidation levels between methane and carbon dioxide. Methane occurs in coal and oil deposits and is also evolved on a large scale as an end-product of many fermentations. Carbon dioxide is also abundantly present in the atmosphere, in natural waters, and as carbonates in the earth. A considerable number of micro-organisms have developed the ability to utilize such compounds as carbon or energy sources. This chapter examines these micro-organisms and the biochemical problems, which are posed by energy transduction and biosynthesis of cell constituents from the one-carbon substrate. It explains the description and physiology of one-carbon-utilizing micro-organisms along with their energy metabolism and carbon assimilation. The utilization of one-carbon compounds is largely confined to prokaryotic organisms. Many enzymes that catalyze the oxidation of one-carbon compounds at a variety of oxidation levels are also extensively studied. The chapter also considers mechanisms that offer a solution to the problem of net biosynthesis from one-carbon units at reduction levels ranging from carbon dioxide to methane.
211 citations
••
TL;DR: The chemistry of atmospheric CH4, CO, and CO2 is treated with a one-dimensional model incorporating the effects of eddy diffusion in the altitude region of 0-120 km.
Abstract: The chemistry of atmospheric CH4, CO, and CO2 is treated with a one-dimensional model incorporating the effects of eddy diffusion in the altitude region of 0–120 km. Methane is well mixed up to about 20 km, and its mixing ratio declines steadily at higher altitudes. Carbon monoxide is well mixed in the troposphere. Its mixing ratio decreases initially in the lower stratosphere, reaches a minimum value of the order of 10−8 near 30 km, and increases steadily at higher elevations. Carbon dioxide is well mixed in the troposphere. Its mixing ratio declines somewhat in the stratosphere, and this decline reflects the importance of anthropogenic production of CO2 and the relatively long time constants for stratospheric diffusion. Mixing ratios of CO and CO2 are comparable near 120 km. Combustion is a minor source of CO in comparison with oxidation of CH4. Oxidation of CH4 also provides a significant source of stratospheric H2O and H2. The principal sinks for CO and CH4 involve reactions with OH. Carbon dioxide is removed at the surface and to a lesser extent in the atmosphere by photolysis. Mean atmospheric residence times for CO and CH4 are 0.3 and 7 years, respectively.
165 citations
••
TL;DR: In this article, the catalytic activities of transition-metal catalysts in methane formation from carbons were investigated at temperatures up to 1050 °C under atmospheric pressure of hydrogen, and it was shown that methane was produced in several stages and the temperature of maximal rate varied from one metal catalyst to another.
153 citations
••
TL;DR: It is concluded that carbon monoxide is produced at a rate of 5x1015 grams per year, a value some 25 times greater than the rate ofcarbon monoxide production from combustion, and hydroxyl radicals are shown to account for both the production of this large amount of carbonmonoxide by methane oxidation and for its removal by carbon mon dioxide oxidation.
Abstract: Consideration of the steady-state equations for stable carbon monoxide and for radioactive carbon monoxide in the troposphere leads to the conclusion that carbon monoxide is produced at a rate of 5x10(15) grams per year, a value some 25 times greater than the rate of carbon monoxide production from combustion. The concomitant residence time for carbon monoxide is 0.1 year, in agreement with a previous estimate of Weinstock. Hydroxyl radicals are shown to account for both the production of this large amount of carbon monoxide by methane oxidation and for its removal by carbon monoxide oxidation. The average concentration of hydroxyl radicals in the troposphere required to achieve this effect is 2.3x10(6) molecules per cubic centimeter, with a daytime concentration of twice that. Levy and McConnell, McElroy, and Wofsy have deduced concentrations of hydroxyl radicals in the troposphere of the same magnitude from purely photochemical considerations, in support of this model.
151 citations
••
TL;DR: In this article, the influence of the catalyst support on the oxidation of methane over palladium has been studied using a microcalorimetric bead reactor, and it has been shown that the reactivity of water towards the catalytic support is an important factor governing the deterioration of catalytic activity.
Abstract: The influence of the catalyst support on the oxidation of methane over palladium has been studied using a microcalorimetric bead reactor. The nature of the support had no detectable influence on the catalytic activity during a given experiment, but was found to affect the long-term stability of the catalyst.Investigations have been made of the kinetics of the oxidation of methane over a palladium/thoria catalyst both in the absence and in the presence of the reaction products. Oxidation was found to be strongly inhibited by the water formed, which tended to cause permanent deactivation of the catalyst; there was also very slight inhibition by carbon dioxide. Measurements of the rates of co-oxidation of methane with other compounds showed that methanol reacted independently, whereas formaldehyde and carbon monoxide were both oxidized competitively.It has been shown that the reactivity of water towards the catalyst support is an important factor governing the deterioration of catalytic activity. In accordance with this there was no evidence of catalyst deactivation when methane was co-oxidized with methanol, which would be expected to displace water.
116 citations
••
TL;DR: Bada and Miller as discussed by the authors showed that an ammonium ion concentration of 10−2 to 10−3 M is necessary for the synthesis of these biomolecules, while Rasool and McGovern suggest that a methane-ammonia atmosphere could have been maintained for 109 years by a low leakage rate of hydrogen.
Abstract: THE suggestion that the primitive atmosphere was highly reducing and consisted mainly of methane, ammonia and water vapour1 is supported by Miller's observation that amino-acids are formed by electrical discharges through such a mixture2 and the synthesis of various biomolecules under presumed primitive Earth atmospheres containing ammonia3. Bada and Miller4 point out that an ammonium ion concentration of 10−2 to 10−3 M is necessary for the synthesis of these biomolecules while Rasool and McGovern5 suggest that a methane–ammonia atmosphere could have been maintained for 109 years by a low leakage rate of hydrogen.
84 citations
•
Esso1
TL;DR: In this article, a process for producing a Methane-rich gas where CARBONACEOUS MATERIAL is STEAM GASIFIED at TEMPERATURES BETWEEN 1100 and 1400* F.I.G.
Abstract: A PROCESS FOR PRODUCING A METHANE-RICH GAS WHEREIN CARBONACEOUS MATERIAL IS STEAM GASIFIED AT TEMPERATURES BETWEEN 1100 AND 1400* F. AND AT PRESSURES BETWEEN 200 AND 2000 P.S.I.G. WITH STEAM RATES BETWEEN 0.1 AND 1.0 WT. H2O/WT. CARBON/HR. IN THE PRESENCE OF AN ALKALI METAL SALT CATALYST COMPOSITION.
57 citations
••
TL;DR: In this article, it was observed that activation of coal to small B.O. can lead to the production of molecular sieves, and the activation energy of methane diffusion is small.
52 citations
••
TL;DR: A valuable and at t ract ive new substrate for the production of microbial cells is methanol, which can be manufactured by catalytic oxidation of methane.
Abstract: For the present several processes for the production of single-cell protein are being developed. The most promising of these processes seems to be the production of yeasts on hydrocarbon substrates and industrial wastes. Production of bio-mass on natural gas or from hydrogen and carbon dioxide is carried out on a laboratory scale only. A valuable and at t ract ive new substrate for the production of microbial cells is methanol, which can be manufactured by catalytic oxidation of methane.
51 citations
••
•
19 Jun 1972
TL;DR: In this article, a major portion of the gas is heated and introduced into a rectifying column and a minor portion is subcooled refluxed into the column as subcooling reflux.
Abstract: Liquefied natural gas is pumped to high pressure and divided into a major portion which is heated and introduced into a rectifying column and a minor portion which enters the column as subcooled reflux. Methane-enriched gas leaves the top of the column at high pressure while liquid ethane and heavier hydrocarbons are withdrawn from the bottom thereof. When the methane-enriched gas is to be delivered at a pressure above the critical pressure of the gas in the column, the heated major portion is expanded with the performance of work before being introduced into the column; the work thus performed is utilized to compress the methane-enriched gas to a pressure above that in the column.
••
TL;DR: In the dual formation of single crystal graphite and polycrystalline carbon from the pyrolysis of methane at 60 cm Hg over thin foils of iron (at 650°C and 750°C), cobalt and nickel (at 750°c), scanning electron microscopy and electron microprobe analysis established that some areas of the large surface grains of these vacuum annealed metal substrates had enhanced activity for carbon deposition as mentioned in this paper.
••
01 Mar 1972-Journal of Research of the National Bureau of Standards Section A: Physics and Chemistry
TL;DR: Experimental PVT data for liquid methane are reported at densities from 1.8 times critical up to the freezing liquid, at temperatures from 91 to 245 K and pressures to 350 bar.
Abstract: A paper with 22 refences gives experimental PVT data for liquid methane at densities from 1.8 times critical up to the freezing liquid, at temperatures from 91-245 K, and pressures to 350 bar; a nonanalytic equation of state is adjusted to these and other PVT data from ideal gas states to the freezing liquid, at temperatures from the triple point to 400 K.
••
TL;DR: The methane concentration of an air sample collected near the stratopause was measured by gas chromatography and determined to be 0.25 plus or minus 0.02 ppm by volume as discussed by the authors.
Abstract: The methane concentration of an air sample collected near the stratopause was measured by gas chromatography and determined to be 0.25 plus or minus 0.02 ppm by volume. The integrity of the air sample with respect to its methane content, the method of analysis, and the result are briefly discussed.
•
•
23 Mar 1972
TL;DR: In this article, a process for the production of methane-rich fuel gas by the gasification of coal in three stages is described, where a partially gasified char recycled from the process is reacted with oxygen and superheated steam at pressures greater than 50 atmospheres and temperatures greater than 2,500*F. to yield a first stage synthesis gas containing hydrogen and carbon oxides.
Abstract: A process for the production of methane-rich fuel gas by the gasification of coal in three stages. In the first stage, partially gasified char recycled from the process is reacted with oxygen and superheated steam at pressures greater than 50 atmospheres and temperatures greater than 2,500*F. to yield a first stage synthesis gas containing hydrogen and carbon oxides. In the second stage, the first stage synthesis gas is reacted with superheated steam and coal at pressures in excess of 50 atmospheres and temperatures in excess of 1,600*F. to yield a partially gasified char entrained in a second stage product gas containing methane, hydrogen and carbon oxides. In the third stage, char and gases from the second stage form a fluidized bed reacting at a pressure in excess of 50 atmospheres and at a temperature in excess of 1,500*F. to form char entrained in a third stage product gas containing methane, hydrogen and oxides of carbon. The third stage char and third stage product gas are separated with the char recycled to the first stage and the product gas is purified by the removal of carbon oxides, hydrogen sulfide and other impurities and the purified product gas is methanated to produce the methane rich fuel gas. Slag formed in the first and second stages is collected in the third stage and is removed from the process after elutriation from the slag of char collected with the slag, which char is returned to the third stage.
••
TL;DR: In the surroundings of natural gas leaks, methane, ethane and possibly some other components of the natural gas are oxidized by microbial activities as long as oxygen is available, demonstrated by an increased oxygen consumption and carbon dioxide production, as well as by increased numbers of different types of bacteria.
Abstract: From the present experiments it may be concluded that in the surroundings of natural gas leaks, methane, ethane and possibly some other components of the natural gas are oxidized by microbial activities as long as oxygen is available. This is demonstrated by an increased oxygen consumption and carbon dioxide production, as well as by increased numbers of different types of bacteria. The resulting deficiency of oxygen, the excess of carbon dioxide, and perhaps the formation of inhibitory amounts of ethylene, are considered to be mainly responsible for the death of trees near natural gas leaks. Also the long period of time needed by the soil to recover, may be due to prolonged microbial activities, as well as to the presence of e. g. ethylene.
••
TL;DR: This report describes enhancement of bacterial methane utilization by clay mineral particles in a simulated aquatic ecosystem that causes some carbon to be recycled in the aquatic ecosystem rather than lost as gas.
Abstract: METHANE is abundantly liberated by bacteria from the sediments of rivers and lakes1. If methane formation exceeds its solubility in water it is released into the atmosphere2. Several species of bacteria oxidize methane as an energy source, converting it into cellular materials or carbon dioxide gas3. Accumulation of carbon derived from methane is involved in the ageing of lakes because it causes some carbon to be recycled in the aquatic ecosystem rather than lost as gas. How much methane carbon is retained in the ecosystem and how much escapes into the atmosphere depends on conditions in the water. This report describes enhancement of bacterial methane utilization by clay mineral particles in a simulated aquatic ecosystem.
••
TL;DR: In this paper, the authors investigated the catalytic activity of methane catalyzed by 13X molecular sieves, in which ~20% of the Na+ had been replaced by transition metal ion in a flow system with reaction temperatures between 253 and 563 °C.
•
23 Mar 1972
TL;DR: In this article, a two-stage downflow gasification of coal to produce a methane rich fuel gas is described, where coal, excess char and slag flow into the second stage in which coal, synthesis gas and steam react whereby the slag is cooled and solidified before it contacts the walls of the reactor.
Abstract: A process for the two-stage downflow gasification of coal to produce a methane rich fuel gas. In a first stage, partially gasified char recycled from a second stage is reacted with super-heated steam and oxygen to produce a first stage synthesis gas. In the second stage, the first stage synthesis gas is mixed and reacted with coal and steam to produce partially gasified char and a hydrogen-rich product gas containing methane. Pressures in the first and second stages are maintained at at least 50 atmospheres. Slag formed in the first stage reaction is maintained in the molten state at temperatures in excess of 2,500 DEG F. Gases, excess char and slag flow into the second stage in which coal, synthesis gas and steam react whereby the slag is cooled and solidified before it contacts the walls of the reactor in the second stage. After removal and separation of the partially gasified char and product gas from the second stage, the char is recycled to the first stage and the product gas is purified and methanated. The solidified slag is collected in the second stage and is thereafter elutriated with steam and quenched before disposal.
01 Mar 1972
TL;DR: In this paper, the high temperature oxidation reactions of carbon monoxide and methane in oxygen-rich atmospheres have been studied in a turbulent flow reactor, and the experimental methods are directly extendable to investigations of higher hydrocarbon oxidations.
Abstract: : The high temperature oxidation reactions of carbon monoxide and methane in oxygen-rich atmospheres have been studied in a turbulent flow reactor. Spatial chemical sampling and gas chromatographic analysis techniques were developed for these studies, and the experimental methods are directly extendable to investigations of higher hydrocarbon oxidations. Overall expressions were developed for the carbon monoxide and methane disappearance rates and for the appearance rate of carbon dioxide in the methane-oxygen reaction. These and other data were used to deduce the re;ative importance of several elementary reactions in the oxidation mechanisms. It was concluded that other reactions in addition to hydroxyl attack on methane are important in governing the methane disappearance rate in oxygen-rich, high temperature systems.
•
23 Mar 1972
TL;DR: A two-stage gasification of coal to produce METHANE-RICH FUEL GAS is described in this paper, where the first stage is composed of two stages and the second stage contains a third stage containing OXIDES, HYDROGEN, and OXides of carbon.
Abstract: A PROCESS FOR THE TWO-STAGE GASIFICATION OF COAL TO PRODUCE METHANE-RICH FUEL GAS. IN THE FIRST STAGE, RECYCLED PROCESSED CHAR PASSES UPWARDLY WHILE REACTING WITH STEAM AND OXYGEN TO YIELD A FIRST STAGE SYNTHESIS GAS CONTAINING HYDROGEN AND OXIDES OF CARBON. IN THE SECOND STAGE, THE SYNTHESIS GAS PASSES UPWARDLY WITH COAL AND STEAM WHICH REACT TO YIELD PARTIALLY GASIFIED CHAR ENTRAINED IN A SECOND STAGE PRODUCT GAS CONTAINING METHANE, HYDROGEN AND OXIDES OF CARBON. THE PRODUCT GAS FROM THE SECOND STAGE IS SEPARATED FROM THE CHAR AND IS PURIFIED BY CONVERSION AND REMOVAL OF CARBON OXIDES, HYDROGEN SULFIDE AND OTHER IMPURITIES, AND THE PURIFIED SECOND STAGE PRODUCT GAS IS METHANATED TO PRODUCE THE DESIRED FUEL GAS. CHAR SEPARATED FROM THE SECOND STAGE PRODUCT GAS IS PASSED THROUGH A FLUIDIZED BED AND SCRUBBED WITH STEAM TO REMOVE PRODUCT GAS AND OTHER VOLATILE MATERIALS WHICH ARE CARRIED BY THE SCRUBBING STEAM TO THE SECOND STAGE PRODUCT GAS CARRIED TO PURIFICATION. THE SCRUBBED RECYCLE CHAR IS CARRIED BY STEAM AT HIGH PRESSURE AND RETURNED TO THE FIRST STAGE. AGGLOMERATION OF COAL IN THE SECOND STAGE IS PREVENTED BY THE RAPID HEATING OF THE COAL TO A TEMPERATURE ABOVE ITS RANGE OF PLASTICITY BY MIXING IT WITH THE HOT PRODUCTS FROM THE FIRST STAGE. IN THE FIRST STAGE THE RATIO OF CHAR AND STEAM TO OXYGEN IS SELECTED TO OBTAIN A REACTION TEMPERATURE ABOVE THE ASH MELTING POINT. THE PRESSURE IN EACH STAGE EXCEEDS 500 P.S.I.G. THE SECOND STAGE TEMPERATURE EXCEEDS 1500*F. AND THE FIRST STAGE TEMPERATURE EXCEEDS 2200*F. GAS VELOCITIES IN BOTH STAGES ARE MAINTAINED BETWEEN 2 AND 12 FEET PER SECOND WHILE THE RESIDENCE TIME OF SOLIDS IN THE FIRST STAGE IS FROM ONEHALF TO FIVE SECONDS AND, IN THE SECOND STAGE, FROM FIVE TO FIFTEEN SECONDS. A MIXING STAGE BETWEEN THE FIRST AND SECOND STAGES PROVIDES A RESTRICTED AREA FOR THE INJECTION OF COAL AND STEAM INTO THE UPWARDLY FLOWING SYNTHESIS GAS TO SEPARATE SOLIDS AND GASES ENTERING THE SECOND STAGE FROM THE FIRST STAGE AND TO ASSURE RAPID MIXING AND REACTION OF THE REACTANTS OF BOTH STAGES. SLAG IS REMOVED FROM THE LOWER END OF THE FIRST STAGE FOR QUENCHING AND DISPOSAL THROUGH A SLAG REMOVAL PORT OF SMALL CROSS SECTIONAL AREA COMPARED TO THE CROSS SECTIONAL AREA OF THE FIRST STAGE. THIS ASSURES RESIDENCE AND REACTION TIME OF THE CHAR IN THE FIRST STAGE SUFFICIENT FOR ITS GASIFICATION WITH STEAM AND OXYGEN AT TEMPERATURES ABOVE THE ASH MELTING POINT. THE RELATIVELY SMALL AREA OF THE SLAG REMOVAL PORT PERMITS CONTROLLED REMOVAL OF MOLTEN SLAG WHILE RESTRICTING THE GRAVITATION OF CHAR TO THE SLAG QUENCHING STAGE. D R A W I N G
•
06 Mar 1972TL;DR: In this article, a process for the liquefaction and subcooling of natural gas with a Claude closed refrigerating cycle is described, where the cycle medium is a mixture of nitrogen and methane.
Abstract: A process for the liquefaction and subcooling of natural gas with a Claude closed refrigerating cycle comprising compressing gaseous cycle medium; cooling resultant compressed gaseous cycle medium; dividing cooled compressed gas into two streams; engine-expanding one stream; and cooling the other stream with the engine-expanded stream to such an extent that said other stream becomes partially liquefied after a subsequent throttle expansion thereof; the improvement comprising employing as the cycle medium, a mixture of nitrogen and methane.
••
TL;DR: In this paper, a determination of the self-broadened linewidth of methane at 2947.88 cm −1 has been made using a stabilized, singlemode helium-neon laser.
Abstract: A determination of the self-broadened linewidth of methane at 2947.88 cm −1 has been made using a stabilized, single-mode helium-neon laser. The width at half-maximum has been found to be 0.16±0.01 cm −1 at atmospheric pressure. By taking into account neighbouring methane components, the variation of the absorption coefficient in the high-pressure region can also be accounted for. The variation of the linewidth with temperature T has also been determined and was found to be close to T −1 . The strength of the methane line nearest the laser emission is 1.76±0.04 atm −1 cm −2 ; this line was found to be located 0.002±0.001 cm −1 from the laser emission.
•
03 Mar 1972
TL;DR: In this article, an improved apparatus and method for the automatic determination of total organic carbon in aqueous media is presented, which comprises two sample injection valves, two reaction chambers, one for converting all carbon (both organic and inorganic) in the sample to carbon dioxide, the other for converting only the inorganic carbon to CO 2, and a methanizer for converting the formed carbon dioxide to methane and a flame ionization detector for measuring the quantity of the methane produced which corresponds to the total and the organic carbon content of the sample, the difference between these two values
Abstract: An improved apparatus and method for the automatic determination of total organic carbon in aqueous media. The invention comprises two sample injection valves, two reaction chambers, one for converting all carbon (both organic and inorganic) in the sample to carbon dioxide, the other for converting only the inorganic carbon to carbon dioxide, a methanizer for converting the formed carbon dioxide to methane and a flame ionization detector for measuring the quantity of the methane produced which corresponds to the total and the inorganic carbon content of the sample, the difference between these two values being the organic carbon content.
••
TL;DR: In this paper, the effects of methane adsorbedding on tungsten and its effects on the imaging of metal surfaces with metal surfaces were investigated using a channel plate image intensifier, and it was shown that the surface is covered with an adsorption layer of CH x, preventing a stable image with higher degree of order.
•
18 Jan 1972
TL;DR: For the purpose of storing and transporting a liquefied combustible gas, in a methane tanker for example, together with a virtually inert gas such as nitrogen in contact with said combustible gases, use is made of additional energy either, as the case may be, in order to liquefy the inert gas - utilizing the evaporation of the combustibility gas to that end - or inorder to reliquefy a liquid inert gas as discussed by the authors.
Abstract: For the purpose of storing and transporting a liquefied combustible gas, in a methane tanker for example, together with a virtually inert gas such as nitrogen in contact with said combustible gas, use is made of additional energy either, as the case may be, in order to liquefy the inert gas - utilizing the evaporation of the combustible gas to that end - or in order to reliquefy the evaporated combustible gas - utilizing the evaporation of the liquid inert gas to that end.