Catalytic kinetics of dimethyl ether one-step synthesis over CeO2-CaO-Pd/HZSM-5 catalyst in sulfur-containing syngas process

CeO2-CaO-Pd/HZSM-5 catalyst was prepared for the dimethyl ether (DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of CeO2-CaO-Pd/HZSM-5 was investigated to ensure that the kinetics experimental results were not significantly influenced by induction period and catalytic deactivation. A large number of kinetic data points (40 sets) were obtained over a range of temperature (240-300 degrees C), pressure (3-4 MPa), gas hourly space velocity (GHSV) (2000-3000 L.kg(-1). h(-1)) and H-2/CO mole ratio (2-3). Kinetic model for the methanol synthesis reaction and the dehydration of methanol were obtained separately according to reaction mechanism and Langmuir-Hinshelwood mechanism. Regression parameters were investigated by the method combining the simplex method and Runge-Kutta method. The model calculations were in appropriate accordance with the experimental data. (C) 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.