In a study of the kinetics of the system carbon-hydrogen-methane, the methane formation rate was determined at pressures up to 40 atm and in the temperature range 650 to 870°C, and the methane decomposition rate a t pressures up to 20 atm and in the temperature range 850 to 725°C. The rate of methane formation, expressed as gram moles per minute per gram of carbon originally in the bed, can be expressed by the equation Formula where k1, k2, k3, k4, and k5 are constants and pH2 and PCh4 are the partial pressures, in atmospheres, of the hydrogen and methane respectively. A mechanism has been suggested which involves the formation of >CH2 groups on the carbon surface.