Investigation on Fischer-Tropsch Synthesis over Cobalt-Gadolinium Catalyst
Cobalt-gadolinium catalyst for Fischer-Tropsch synthesis was prepared by impregnation method with commercial silica gel, and its texture properties were characterized by BET, XRD, and TPR. The catalytic performance of the catalyst was tested in a fixed bed reactor. The results showed that the addition of gadolinium to the cobalt catalyst might decrease the size of cobalt particles, and increased the dispersion of catalytic active cobalt phases. The carbon number distributions for the catalysts was calculated by ASF equation.
Fischer-Tropsch synthesis, cobalt-based catalysts, gadolinium, carbon number distributions.
Effect of the Support Shape on Fischer-Tropsch Cobalt Catalyst Performance
Cobalt catalysts were supported on extruded silica carrier and different-type (SiO2, γ-Al2O3) commercial supports with different shapes and sizes to produce heavy hydrocarbons for Fischer-Tropsch synthesis. The catalysts were characterized by N2 physisorption and H2-TPR. The catalytic performance of the catalysts was tested in a fixed bed reactor. The results of Fischer-Tropsch synthesis performance showed that the cobalt catalyst supported on spherical silica supports displayed a higher activity and a higher selectivity to C5+ products, due to the fact that the active components were only distributed in the surface layer of spherical carrier, and the influence of gas diffusion restriction on catalytic performance was weakened. Therefore, it can be concluded that the eggshell cobalt catalyst was superior to precious metals modified catalysts in the synthesis of heavy hydrocarbons.
Fischer-Tropsch synthesis, cobalt catalyst, support shape, heavy hydrocarbons.