Ferrierite vs. γ-Al2O3: The superiority of zeolites in terms of water-resistance in vapour-phase dehydration of methanol to dimethyl ether

The catalytic conversion of methanol to dimethyl ether (DME) over a series of home-made FER-type zeolites having different acidities and commercial γ-Al2O3has been studied with the aim to understand the impact of adding water in the reactant stream on the catalytic behavior on investigated materials. Co-feeding water with methanol, the alcohol conversion was slightly reduced over the investigated zeolites while the catalytic activity of γ-Al2O3, the traditional catalyst of MeOH-to-DME conversion, was strongly inhibited. It was also found that, for the investigated zeolites, both the amount and the initial deposition rate of the coke formed during the reaction were reduced when water was co-fed with methanol while no significant effects on both methanol conversion and DME selectivity were observed under the investigated conditions.