Low-Temperature Fischer–Tropsch Synthesis on Cobalt Catalysts—Effects of CO2

Abstract

Effects of CO2 on low-temperature Fischer–Tropsch synthesis were investigated with four different cobalt catalysts in an experimental study. CO2 was found to behave as an inert gas component with three catalysts, however, a negative effect on Fischer–Tropsch reaction rate and catalyst deactivation was observed in one case (Co-La-Ru-SiO2). CO2 effects in a large-scale FTS slurry reactor were simulated by means of a mathematical reactor model using the kinetic information gained in the experiments. The reactor volume required for achieving a desired CO conversion must be higher if the syngas contains CO2, more strongly in cases where the catalyst exhibits a deactivation behavior in the presence of CO2. These model calculations can contribute to process optimization with respect to CO2 removal before synthesis.