Methanol dehydration into dimethylether over ZSM-5 type zeolites: Raise in the operational temperature range

Abstract

Zeolites having different pore topologies were tested in the dehydration of methanol into dimethylether (DME) under inert and oxidative atmosphere. The experiments were carried out under air to inhibit the Methanol-To-Hydrocarbons (MTH) reaction, which tends to decrease the selectivity in DME. In addition, the presence of air led to broadening the operational temperature range (OTR) up to 400 °C, while maintaining the DME selectivity above 90% during 50 h on stream. Among the solid acid catalysts, the ZSM-5 zeolites exhibited the higher catalytic activity, with a degree of methanol conversion close to 75%. Furthermore, H-[F]ZSM-5 zeolite, prepared via a fluoride-mediated route, remains the more stable and selective toward DME at 400 °C.