Computational fluid dynamics simulation of Fischer-Tropsch synthesis coupled with a novel reaction kinetics using trimetallic catalyst over a biomass-based support

Abstract

A mathematical modeling based on the computational fluid dynamics (CFD) was performed in this work. The reactive flow behavior in a tubular reactor was modeled for Fischer-Tropsch synthesis (FTS) using a novel trimetallic catalyst supported on a low-cost and renewable carbonaceous material. The fixed bed reactor was simulated as a porous media using a commercial software package (COMSOL Multiphysics). In this study, major attention has been paid to the species transport and reaction kinetics, as a fundamental stage in CFD simulation of FTS. The reaction kinetics was evaluated using Eley-Rideal theory assuming the molecular adsorption of CO based on the enol mechanism. Furthermore, the products distribution was accounted in the kinetics study by defining a mathematical expression and the kinetics parameters were optimized using genetic algorithm (GA). The activation energy and heat of H2 adsorption were estimated as 62.63 and −29.52 kJ/mol, respectively. The role of operational conditions was critically evaluated on the partial pressure profiles of the species, and the CFD results were validated with the experimental data. While increasing total pressure improved the partial pressure of C5+ hydrocarbons to 1.2 bar, increasing temperature to 310 °C limited the chain growth. The employed modeling and novel catalyst design can provide promising overview of the FTS reaction mechanism and products selectivity in fixed bed reactors.