Investigation of Fischer-Tropsch Synthesis Over Granule Type of gamma-Alumina Supported Cobalt Catalyst

Abstract

This paper focuses on the granule type of gamma-alumina-supported cobalt Fischer-Tropsch catalysts. Mesoporous gamma-Al2O3 spherical (similar to 1 mm diameter) catalysts were prepared and were characterized by X-ray diffraction and N-2 physisorption. The granular alumina surface areas were in the mesoporous range of 108 m(2)/g, with an average pore diameter of 10 nm. The metal loading efficiencies of cobalt and the promoter effect of gamma-Al2O3 supported cobalt catalysts were investigated by preparing a series of catalysts, consisting of 5-20 wt% cobalt and a second metal promoter (Ru or Pt), by a dry impregnation method. All catalysts were extensively characterized by N-2 physisorption, TPR, XPS, XRD, SEM/EDX and TEM methods. In addition, the catalysts were evaluated in terms of their Fischer-Tropsch synthesis activity and selectivity in a fixed-bed reactor. The addition of the promoter to supported cobalt catalysts significantly increased the dispersion of cobalt, the Co-metallic surface area and the cobalt surface density, resulting in an enhancement of the Fischer-Tropsch synthesis activity in the fixed-bed reactor.