Methane and carbon monoxide

Decomposition. Acetaldehyde decomposes at temperatures above 400°C, forming principally methane and carbon monoxide [630-08-0]. The activation energy of the pyrolysis reaction is 97.7 kj/mol (408.8 kcal/mol) (27). There have been many investigations of the photolytic and radical-induced decomposition of acetaldehyde and deuterated acetaldehyde (28—30). 

A definition based upon the NMHC concentration might require nonmethane hydrocarbons to contribute insignificantly to atmospheric reactivity. Such a region might still contain very low concentrations of nonmethane hydrocarbons, so long as their sum total reactivity does not significantly contribute to that of methane and carbon monoxide. This is to say, in clean air... 

Under certain conditions acetaldehyde decomposes into methane and carbon monoxide in a second-order reaction. 

This perturbation comes only from the carbonate in the approximately 100 meters thick surface mixed layer it contains about 0.15 g carbon/cm2, approximately equal to that in the atmosphere and to the organic carbon dissolved in the total depth of the sea. In the case of organic carbon, the total depth of the sea is involved because bacterial decomposition occurs at all depths, producing methane and carbon monoxide with both of which the sea is saturated, so that these gases are bubbling up from all depths. In comparison the sea is not saturated with C02 at any depth. 

MRG [Methane rich gas] A catalytic steam-reforming system, similar to the classic syngas reaction of steam with a hydrocarbon mixture, but yielding hydrogen, methane, and carbon monoxide in different proportions. The system is thermodynamically balanced,... 

At 5 1 8°C, acetaldehyde vapor decomposes into methane and carbon monoxide according to CH3CHO - CH4 + CO. In a particular experiment carried out in a constant-volume BR (Hinshelwood and Hutchison, 1926), the initial pressure of acetaldehyde was 48.4 kPa,... 

At elevated temperatures, acetaldehyde (CH3CHO, A) undergoes gas-phase decomposition into methane and carbon monoxide. The reaction is second-order with respect to acetaldehyde, with kA = 22.2 L mol-1 min-1 at a certain T. Determine the fractional conversion of acetaldehyde that can be achieved in a 1500-L CSTR, given that the feed rate of acetaldehyde is 8.8 kg min-1, and the inlet volumetric flow rate is 2.5 m3 min-1. Assime T and P arc unchanged... 

The tabulated data have been obtained for the vapor phase decomposition of ethylene oxide (A) into methane and carbon monoxide at 414.5°C (Heppert Mack, JACS 5J 2706, 1929). Show that the rate equation is first order, nt = 2na0-na... 

Finally, it is of interest, not only to the student of industrial archelogical history, but also to the modern technologist, to refer to coal gasification. A few decades ago the gasification of coal provided a means of supplying communities with coal gas, a mixture of hydrogen, methane and carbon monoxide, which could be ignited in burners and used as a domestic or industrial source of heat. With the discovery of natural gas... 

Acetaldehyde decomposes homogeneously at temperatures of several hundred degrees Celsius to produce methane and carbon monoxide,... 

This reaction sequence is similar to that described for acetaldehyde decomposition to methane and carbon monoxide Reactions that produce stable products actually occur only... 

The fate of the free acyl radical 68 and radical 74 is not known. Most probably it is a constituent of polymer deposits on the wall of the irradiation vessel which hitherto have not been identified more definitely.29 Moreover, the identification of methane and carbon monoxide among the gaseous products of the photolysis of 4-methylphenyl acetate (55) provides evidence for the existence of the acetyl fragment. This intermediate is expected to decarbonylate to give carbon monoxide and a methyl radical, which in turn abstracts hydrogen from the solvent.34... 

Methane and carbon monoxide are presently the two primary raw materials of practical importance in Ci hydrocarbon chemistry. According to the present industrial practice, natural gas (methane) or coal can be converted to a mixture of carbon monoxide and hydrogen called synthesis gas ... 

The two approaches, however, are interconvertible, since methane itself is obtained from synthesis gas in the methanation reaction. Both methane and carbon monoxide, in turn, can be converted to hydrocarbons. 

The sum of measured volumes of these gases represented less than 1 percent of the total gas volume generated. However, the solubility of these gases in the reaction water was not accounted for. Any one of these gases (except methane and carbon monoxide), or a combination of them, could contribute to the observed odor. Furthermore, the reaction of the slag with water may give rise to potential health hazards if workers are exposed to excessive concentrations of these gases. 

SCHMIDLIN KETENE SYNTHESIS. Formation of kelene by thermal decomposition of acetone over electrically heated wire at 500-750 degrees by a reaction involving radical formation with generation of methane and carbon monoxide. 

Farre-Rius, F., Guiochon, G. Rapid analysis by gas chromatography. Separation of a mixture of oxygen, nitrogen, methane and carbon monoxide. J. Chromatog. 13, 382 (1964). 

Swann, K., Walker, J. A. J. Automatic gas chromatographic analysis for hydrogen, oxygen, nitrogen, methane and carbon monoxide in carbon dioxide. Rep. U.K. Atom-Energy Auth. TRG 1867 (C) (1969). - Anal. Abstr. 19, 2153 (1970). 

Jones, R.D., and Amador, J.A. (1993) Methane and carbon monoxide production, oxidation and turnover times in the Caribbean Sea as influenced by the Orinoco river. J. Geophys. Res. 98, 2353-2359. 

The carbon dioxide photoreduction upon visible light has been performed using Pt-CdS-Ru02 powder (particles <1 pm) and K[Ru(H-edta)Cl] 2H20 in C02 saturated water solution [93], Formic acid, formaldehyde as the main products and trace amounts of methanol, methane, and carbon monoxide have been identified. Also hydrogen and oxygen as products of water decomposition were evolved. The proposed mechanism of the process is given below (L = H-edta) ... 

Photochemical reduction of C02 was also achieved in the presence of the p-type semiconductor (copper oxide) or silicon carbide electrodes [97]. Irradiation of this system generates methanol and methane as the main products in the case of CuO electrode whereas hydrogen (with efficiency about 80%), methanol (16%), methane, and carbon monoxide in the case of SiC electrode. Also Ti02/CuO systems appeared relatively efficient (up to 19.2% quantum yield) in photocatalytic C02 to CH3OH reduction [98]. 

Methane and carbon monoxide, according to Losanitsch and Jovitschitsch,4 unite to acetaldehyde and its condensation and polymerization products according to Hemptinne,5 aldehydic substances. 

Methyl Alcohol.—According to Maquenne,2 the vapor of methyl alcohol is decomposed by the silent discharge chiefly into methane and carbon monoxide some hydrogen, ethylene, and acetylene and very little carbonic acid, are also produced. The quantity of hydrogen increases with increasing pressure (from 3-100 mm. mercury pressure), that of the other products decreases ... 

A schematic diagram for the processing of synthesis gas to meet these three objectives using a combination upgrader/PSA unit is presented in Figure 9. A portion of the synthesis gas is diverted to the cold box for partial condensation and separation of the bulk of the methane and carbon monoxide from the hydrogen. The enriched (94-98%) H2 vapor fraction is reheated... 

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