Kinetic Model for the Conversion of Chloromethane into Hydrocarbons over a HZSM-5 Zeolite Catalyst

Abstract

The conversion of chloromethane into hydrocarbons over a HZSM-5 zeolite based catalyst is investigated with the aim of establishing a kinetic model suitable for simulating this process for indirect valorization of the methane contained in shale gas. The experimental data were obtained in an isothermal fixed bed reactor under a wide range of operating conditions: temperature, 300-450 °C; space-time, 1-12 gcatalyst h/mol CH2; chloromethane partial pressure, 0.375-1.5 atm; and time on stream, up to 255 min. The reaction scheme is composed of eight components and lumps (chloromethane, C2-C4 olefins, C2-C4 paraffins, C5-C10 aliphatics, aromatics BTX, methane, hydrochloric acid, and chlorinated hydrocarbons), which are involved in ten single reactions. The catalyst deactivation by coke deposition has been quantified by an equation, which is dependent on the concentration of chloromethane in the reaction medium. The kinetic model is suitable for predicting accurately the effect that reaction conditions have on products distribution and their evolution with time on stream.