A novel catalytic process for SNG synthesis

Methane rich city gas has been synthesized by means of steam reforming of n aphtha; however, the produced gas always contains significant concentration of CO and CO2. Therefore, development of a methane production process cont aining no CO and CO2 removal processes is strongly requested. Authors reported in the previous paper that C3H8->2CH(4)+C(1) took place ov er Ni/SiO2 with 90% selectivity. In this paper, the catalyst supports were studied and found that neutral SiO2 and alpha-Al2O3 are suitable but the ac tivity was much reduced over Ni supported on acidic SiO2-Al2O3. Catalyst wa s diluted by various materials to avoid blocking-up by the deposited carbon . Several diluted materials affected the conversion, alpha-Al2O3 and basic MgO accelerated the reaction which may be due to interaction between Ni and dilution materials with direct contact. Over Ni/SiO2, reaction (1) took pl ace with 90% selectivity, so that the produced gas always contained Hz form ed by the C3H8-->3C+4H(2)(2). It has confirmed that H-2 in a high concentra tion of CH4 can be reacted with C3H8 to produce CH4. From these results, a following simple synthesis process can be constituted; the first step is CH 4, H-2, and solid C formation from C3H8, and the second step is succeeding H-2 consumption process of the produced gas in the first step.