Kinetic Model of Product Distribution over Fe Catalyst for Fischer−Tropsch Synthesis^†

Abstract

A new kinetic model of the Fischer−Tropsch synthesis (FTS) is proposed to describe the non-Anderson−Schulz−Flory (ASF) product distribution. The model is based on the double-polymerization monomers hypothesis, in which the surface C 2 * species acts as a chain-growth monomer in the light-product range, while C 1 * species acts as a chain-growth monomer in the heavy-product range. The detailed kinetic model in the Langmuir−Hinshelwood−Hougen−Watson type based on the elementary reactions is derived for FTS and the water−gas-shift reaction. Kinetic model candidates are evaluated by minimization of multiresponse objective functions with a genetic algorithm approach. The model of hydrocarbon product distribution is consistent with experimental data (<C 45 ). The new model gives a sound interpretation of the experimental data.