Atmospheric Production Process for Substitute Natural Gas from Saturated Hydrocarbons 1. Utilization of Catalytic Reaction for Atmospheric Methane Formation

In order to develop a novel production process for substitute natural gas (SNG), SiO2-supported metal catalysts effective for methane formation from propane and butanes are investigated under atmospheric pressure. Two reactions, namely, methane formation, C3H8→2 CH4+C, and decomposition, C3H8→3C+4H2, took place over the analyzed metal supported catalysts. The highest activity is measured for Ni/SiO2, revealing 100% conversion and over 90% selectivity for methanation at 500° C. As far as the activities of other metal supports are concerned, the order is found to be Ni»Co>Fe> Pt>Pd. Butanes show 95~99 % conversion and 80% selectivity over Ni/SiO2 at 500°C. Adopting the condition of less than 2, 700h-1 is found suitable for selective CH4 formation. Supplying the feed of C3 H8/H2=0.5, only hydrogenolysis of propane takes place over Ni/SiO2 above 250°C, and the conversion reachs 90% and 100% at 350°C and 500°C, respectively.