Direct coal methanation

Hydrane A coal gasification process in which coal is hydrogenated directly to methane, using hydrogen gas under pressure, preheated to a high temperature. Developed by the U.S. Bureau of Mines as of 1980 it had not been fully piloted. 

In the experimental studies, tests have been made on the direct steam methanation of coal in two types of equipment. Batch tests have been conducted in small rocking-type high pressure autoclaves. Continuous flow experiments have been made in a 1-in. reactor, 5 ft. long, under Stage 2 conditions using simulated Stage 1 gas. 

Rather than prepare monoliths, directly, for methane storage, Celzard et al. (2005) prepared chemically AC (using NaOH) from an anthracite from a German (Sophia) coal mine, by compacting granular size fractions at pressures up to 220 MPa. It was found that although compaction increased the bulk density of the material, there was no effect on... 

Synthesis gas is obtained either from methane reforming or from coal gasification (see Coal conversion processes). Telescoping the methanol carbonylation into an esterification scheme furnishes methyl acetate directly. Thermal decomposition of methyl acetate yields carbon and acetic anhydride,... 

Gasification technologies for the production of high heat-value gas do not all depend entirely on catalytic methanation, that is, the direct addition of hydrogen to coal under pressure to form methane. 

Reduction of sulfur dioxide by methane is the basis of an Allied process for converting by-product sulfur dioxide to sulfur (232). The reaction is carried out in the gas phase over a catalyst. Reduction of sulfur dioxide to sulfur by carbon in the form of coal has been developed as the Resox process (233). The reduction, which is conducted at 550—800°C, appears to be promoted by the simultaneous reaction of the coal with steam. The reduction of sulfur dioxide by carbon monoxide tends to give carbonyl sulfide [463-58-1] rather than sulfur over cobalt molybdate, but special catalysts, eg, lanthanum titanate, have the abiUty to direct the reaction toward producing sulfur (234). 

Robert Boyle, an Irish chemist noted for his pioneering experiments on the properties of gases, discovered methanol (CH3OH) in 1661. For many years methanol, known as wood alcohol, was produced by heating hardwoods such as maple, birch, and hickory to high temperatures m the absence of air. The most popular modern method of producing methanol, which IS also the least costly, is from natural gas (methane) by the direct combination of carbon monoxide gas and hydrogen in the presence of a catalyst. Methanol also can be produced more expensively from oil, coal, and biomass. 

These operations carry energy penalties, and the heat of combustion released when burning the methane, hydrogen, or carbon monoxide produced is less than the energy that would have been released had the coal been burned directly. To produce heavier liquids, the equimolar mixture of hydrogen and carbon monoxide (water gas, also known as synthesis... 

Direct production of methane from coal is called coal hydrogasification. Several technologies have been developed to make city gas from coal. The main reaction in coal hydrogasification is... 

If we look at the past 2000 years history of fuels, usage has consistently moved in the direction of a cleaner fuel wood —> coal —> petroleum —> propane —> methane as shown on the next page. 

Anaerobic digestion to methane, on-site combustion, mixing with coal to form solid fuel Direct combustion, can utilize carbon dioxide from industrial flue gas, can grow in municipal waste facilities... 

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