Kinetics and modelling of dimethyl ether synthesis from synthesis gas

The kinetics of the dual catalytic methanol and dimethyl ether (DME) synthesis process over a commercial CuO/ZnO/Al2O3 (methanol forming) and a gamma-alumina (dehydration) catalyst have been investigated at 250 degrees C and 5 MPa using a gradientless, internal-recycle-type reactor. A kinetic model for the combined methanol + DME synthesis based on a methanol synthesis model proposed by Vanden Bussche and Froment (1996) J. Catal., 161, 1-10)and a methanol dehydration model by Bercic and Levee (1993) Ind. Engng Chem. Res., 31, 1035-1040) has been tested using results obtained from a wide range of CO2:CO feed ratios. Results at different COx:H-2 ratio and catalyst loading ratios were also obtained. Catalyst deactivation was observed during DME synthesis at high space velocities and a large ratio of dehydration catalyst. (C) 1999 Elsevier Science Ltd. All rights reserved.