The synthesis of methane and heavier hydrocarbons in the system graphite-ironserpentine at 2 and 4 GPa and 1200ºC
Anatoly A. Tomilenko, Anatoly I. Chepurov, Valeri M. Sonin, Taras A. Bulbak, Egor I. Zhimulev, Aleksei A. Chepurov, Tat’yana Yu. Timina and Nikolai P. Pokhilenko
The formation of hydrocarbon compounds at high pressures and high-temperatures corresponding to the P-T conditions of the Earth’s mantle has long been discussed in scientific literature. This paper presents the experimental study on synthesis of methane and heavier hydrocarbons in the system graphite-iron-serpentine at 2 and 4 GPa and 1200ºC. Serpentine Mg3[Si2O5] (OH)4 was used as a source of hydrogen (in the form of hydroxyl groups). For the first time, aliphatic hydrocarbons (from pentane to hexadecane) and oxygenated hydrocarbons (alcohols, aldehydes and ketones) were obtained as products in the experiments from graphite and water in the presence of metallic iron. The presence of oxygen-containing hydrocarbon compounds was caused by an oxygen excess, as hydrogen was deficient in the system studied. The results of experiments demonstrate the stability of heavy hydrocarbons in the pressure interval 2–4 GPa and temperature 1200ºC.
Keywords: High pressure, High-temperature, Hydrocarbons, Earth’s Mantle, Graphite, Iron