Kinetics and modelling of dimethyl ether synthesis from synthesis gas

Abstract

The kinetics of the dual catalytic methanol and dimethyl ether (DME) synthesis process over a commercial CuO/ZnO/Al 2O 3 (methanol forming) and a γ-alumina (dehydration) catalyst have been investigated at 250°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 Levec (1993) Ind. Engng Chem. Res., 31, 1035–1040) has been tested using results obtained from a wide range of CO 2 : CO feed ratios. Results at different CO x : 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.