Partial oxidation of coal

Partial oxidation of coal to form either synthetic fuel, syngas, or synthetic natural gas represents a potential use of oxygen (see Fuels, synthetic). 

This process (usually with addition of steam) can also be used to generate gas mixtures from partial oxidation of coal for synthetic gasoline production (see (4), above). Fluidized beds offer convenience for continuous handling of the feed solids. 

Several important chemical reactions for the conversion of coal to methane are shown in Table 2. Steam conversion involves the reaction of coal with steam to produce hydrogen and carbon monoxide. Hydrogen conversion is a reaction in which coal and hydrogen react to form methane. Oxygen conversion produces hydrogen and carbon monoxide by partial oxidation of coal. Methan-ation involves a reaction in which methane and water are produced from carbon monoxide and hydrogen. The water gas shift reaction between carbon monoxide and steam produces carbon dioxide and hydrogen. 

Partial Oxidation of Coal (Coal Gasification Processes)... 

V. Happe, Partial Oxidation of Coal in A. V. Slack, G. Russel James (eds) Ammonia , Part I, 325-354, Marcel Dekker, New York, 1973. 

The production of synthesis gas is an expensive process irrespective of whether one starts with methane or coal. The chemical reason is that the partial oxidation of coal or methane with steam to form CO and H2 is endothermic, and a high energy input is therefore needed. This energy comes from burning additional CH or coal. A prerequisite for an economic process is therefore that CH or coal must be available at low cost. 

Provide hydrogen source from steam reforming or partial oxidation of coal. 

Mechanochemical Mechanism of Partial Oxidation of Coal with Formation of Suboxides... 

A known solntion to this problem is creating and ntUizing power installations with coal-fired fuel cells (FC) [1-3]. As a rule, coal is first gasified, and then the prodncer gas is fed to fuel cells. However, carbon oxide, which is formed by partial oxidation of coal and hydrocarbons, is an extremely unstable compound that recombines, under specific conditions, to solid carbon, i.e. fuel soot, which clogs the FC pores and damages the electrochemical equipment. 

The spontaneous partial oxidation of coal fines into synthesis gas can proceed [55] by introducing this feedstock with steam into the membrane oxidation compartment as illustrated schematically in Fig. 7.8. 

The heat required for gasification is supplied by the partial oxidation of coal. Overall, the gasification reactions are exothermic, so waste heat boilers often are used at the gasifier effluent. The temperature, and therefore composition, of the product gas depends upon the amount of oxidant and steam, as well as the design of the reactor. 

The heat provided for the above reaction is from partial oxidation of coal with a substoichiometric amount of oxygen. Thus, the overall reaction of the Fe203 reduction and coal partial oxidation can be written as ... 

Figure 28.2 illustrates a process that starts with coal or oil as a raw material. The process includes coal handling, preparation, and pulverization and partial oxidation of coal or oil to synthesis gas, followed by carbon and ash removal, carbon monoxide conversion, carbon dioxide and H2S removal, low temperature scrubbing with liquid nitrogen, and compression for ammonia synthesis. Air separation and sulfur recovery are steps unique to coal or heavy oil feedstocks. 

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