Kinetics of CO hydrogenation over coprecipitated cobalt-alumina

Abstract

The kinetics of CO hydrogenation over coprecipitated 36 wt% Co/Al2O3 was studied in a fixed-bed microreactor at atmospheric pressure. Intrinsic kinetic data were obtained in the initial rate region using four different CO concentrations and two different H2/CO ratios over the 473–523 K temperature range. The surface carbide mechanism with dissociative adsorption of hydrogen as the rate controlling step gives the most plausible kinetic model among the eight different models tested. C1–C4 production rates are found to be strongly influenced by temperature, and optimum C1–C4 hydrocarbon selectivity is obtained at 508 K. The activation energy for CO consumption and CH4 formation are calculated as 74±2 kJ mol−1 and 84±2 kJ mol−1 respectively. ©1997 SCI