Evolution of molecular hydrogen during the atmospheric oxidation of coal

Coals from different provenances were oxidized at low temperatures (55–95 °C) under controlled conditions in small glass reactors. A detailed analysis of the gases produced revealed small but appreciable amounts of molecular hydrogen in addition to the more commonly reported products of coal oxidation, i.e. carbon dioxide, trace amounts of carbon monoxide and light hydrocarbons. The production of hydrogen is an oxidation correlated process since in an inert atmosphere negligible concentrations were detected.