Fischer-Tropsch wax catalytic cracking for the production of low olefin and high octane number gasoline: Experiment and molecular level kinetic modeling study

Abstract

A molecular level kinetic model of Fischer–Tropsch wax catalytic cracking based on the structural unit and bond-electron matrix framework was developed. A molecular compositional model was built according to the detail molecular characterization data, containing 225 representative molecules. The reaction law was studied and then transformed to 17 reaction rules based on experimental data under different reaction conditions. All molecules traversed reaction rules, and a reaction network, including 700 molecules and 2029 reactions, was formed. The model parameters were reduced based on linear free energy relationship and tuned by experimental data. The predicted values of the model were in good agreement with the experimental data, with a maximum absolute error of 2.89 wt% and a minimum absolute error of 0.02 wt%. The model predicted that gasoline olefin content will achieve less than 25 wt% and RON > 90 under the reaction conditions of 510 °C, CTO 12 g/g and WHSV 6 h−1. The modelling also demonstrated that the feedstock was consumed rapidly, and multiple reactions could occur immediately. Thus, secondary reactions play an important role in the production of low olefin and high octane number gasoline.