Evaluation of Ru promoted Co/ γ -Al2O3 Catalysts in Fischer-Tropsch Synthesis in a CSTR
S.A. Hosseini, A. Taeb, F. Feyzi
Abstract
Alumina supported cobalt catalysts promoted by Ru were prepared by co-impregnation method and were investigated in a CSTR. The prepared catalysts have been characterized by XRD, TGA, TPR, H2-chemisorption and BET measurements and the results are reported. The selected Co loadings for making of catalysts were 15 and 25 wt. %, while the loading of Ru was 1wt. %. Characterization studies showed that the reduction of Ru promoted catalyst with lower content of cobalt (15 wt.%) shows higher reduction than the other sample (25 wt.%), as well as, better dispersion of Co on the support ( γ -Al2O3), reduction of particle size of the metal, and pore volume of catalysts. For this work, fractional factorial experimental designs for the evaluation of cobalt catalysts in Fischer-Tropsch synthesis (FTs) were employed. The following reaction parameters were used as independent variable: Temperature, Pressure, GHSV (Gas Hour Space Velocity), rpm and Co wt.%. Using of this method, the best process conditions were achieved. These experiments demostrated that increase of temperature increases CO conversion and C1 selectivity but reduces C5+ selectivity. Increase of Cobalt loading, rpm and GHSV, shifts the reaction toward the production of heavier components. During the reaction, catalysts were deactivated. Deactivation of catalysts during the reaction reduces the rate of secondary reactions, which results in wax production.
