Research On Catalyst For Methanation Of Coal Gas

The synthesis of natural gas based on methanation from coal gas is one of the important approaches of coal clean utilization.The design and synthesis of methanation catalysts with high activity and high stability are of significant in the efficient utilization of coal.This dissertation contributes to the studies on methanation catalyzed by supported nickel catalysts.The nickel catalysts loaded on ZrO2-SiO2 composite oxide support have mainly been studied,and effect of preparation conditions of ZrO2-SiO2 support and catalyst has been investigated.The structures of catalyst have been characterized,in order to build up a relationship between structure and performance.It was found that as compared to single SiO2, ZrO2-SiO2 composite supported Ni catalysts exhitied higher methanation activity. Effect of preparation conditions of ZrO2-SiO2 support on catalyst activity and structure has been investigated.It was found that:the catalyst showed the best performance when the ratio of ZrO2 to SiO2 was 45%; The increase of pH value of impregnating solution contributed to forming small tetragonal zirconia, which was in favor of methanation; When the calcinations temperature of support was 550℃, the grain size was the best for methanation.Effect of preparation conditions of catalyst on catalyst activity and structure has been investigated.The increase of Ni loading amount with limits from 4% to 10% could enhance the activity of Ni/ZrO2-SiO2, but if the Ni loading was too high, such as 12%, acivite component could piped up on the support, and catalyst activity could reduced; Calcined at 450℃could strengthen interaction between NiO and the support and promoted the dispersion of NiO.