The Research Of Nickle-based Catalysts For SNG Production From Syngas

In this work high performance methanation catalysts were prepared with Ni as an activity center. Compared with kinds of carriers on the performance of methanation, MgO improved Al2O3 was chose as the carrier, the optimum nickel loading of the catalyst is about 15%. Additional La2O3,CeO2 in a trace of amount could improve the properties of stability, reduce carbon deposition and prevent from sintering.Different kinds of precipitants have a great impact on the catalysts'performance of methanation. The characterization of the catalysts were determined by XRD,H2-TPR,BET,TPO,TPD. Based on the results, the surface areas of the catalysts by urea preparation reached up to 223.55 m2·g-1, which suggested an stabilized catalytic activity; the catalyst prepared by ammonia precipitant possessed smaller partial diameter, combined more stable with carrier, but the stability for methane was lower than by ammonium carbonate precipitant. It was indicated that the precipitants mainly affected the crystal-phase formation process of the catalyst active component, the dispersion of active Ni on the catalyst surface and hydrogen adsorption capacity.The properties of catalyst changed while adding another metal components. Adding Cu will lead to the decrease of crystal mean particle size and the increase of distribution. Ni-Cu interaction could reduce the loss of active components especially at high temperature. The promoter Mn can reduce the reduction temperature. The activity is obviously higher than Ni-based catalysts at 300-400℃due to the electron effect resulted from the different oxidation-reduction potential of Mn.