Selective methanol-to-dimethyl ether conversion in a through-flow γ-Al2O3 catalytic membrane contactor: Performance and comparative analysis

Dimethyl ether (DME) is a clean and efficient alternative fuel and chemical intermediate, typically produced by methanol dehydration over solid acid catalysts. In this study, the catalytic performance of a gamma-Al2O3 membrane operated in a through-flow configuration was evaluated for DME production. The membrane exhibited high methanol conversion and complete DME selectivity (100 %) over the 260-300 degrees C temperature range, showing optimal performance at 280 degrees C and low WHSV (0.4 h- 1), where equilibrium conditions are approached. Comparative tests with gamma-Al2O3 pellets demonstrated the membrane superior selectivity and enhanced stability with the time-on-stream. A 30-hour time-on-stream experiment showed a good resistance of membrane to deactivation, with catalytic activity fully restored through a thermal regeneration step. The gamma-Al2O3 membrane was further benchmarked against literature-reported ZSM-5 and BEA zeolite membranes, showing better performance in the explored operating conditions.