Experimental Study on Reactions of Graphite and Siderite with Supercritical Water

In order to investigate the formation mechanism of abiogenetic hydrocarbon in the deep earth, experiments on reactions of graphite and siderite with supercritical water have been conducted using the apparatus of diamond anvil cell (DAC) under temperature about 800～1 500 ℃ and pressure approximately above 1 GPa. The gas phase products have been analyzed by means of gas chromatography, which show that both reactions can generate a large number of methane, accompanied with small amount of CO2 and CO and some other hydrocarbons. The above results suggest that under the high temperature and pressure conditions in the earth's interior, reactions of carbon-bearing materials with supercritical water is likely a new and important mechanism in hydrocarbon formation.