Application of nanosized zeolites in methanol conversion processes: A short review

The effective conversion of methanol toward high-added value molecules, such as dimethyl ether (methanol-to-dimethyl ether process, MTD), olefins (methanol-to-olefins process, MTO), or gasoline-cut hydrocarbons (methanol-to-gasoline process, MTG), is of paramount importance for the transition toward a methanol-based economy. In these processes, zeolites are efficient catalysts owing to their shape selectivity and tuneable acidity. Furthermore, the control of the crystal size of zeolites allows controlling the residence time of the involved species inside the catalytic crystal, with an effect on activity, product distribution, and coke deposition. This work focuses on the recent studies on the application of nanosized zeolites in MTD, MTO, and MTG processes. The results are critically discussed especially in terms of products distribution, coke formation, and deactivation. The methods to prepare the nanosized zeolites are also mentioned, although this aspect is beyond the scope of this review, which is to emphasize the impact of the crystal size on the zeolite-catalyzed methanol conversion reactions.