Novel Zeolite Catalysts for Methanol to Hydrocarbon Transformation

Hydrothermal synthesis of H-ZSM-5 coatings with controllable crystal size and Si/Al ratio has been performed. The obtained coatings were studied in the methanol to hydrocarbon (MTH) reaction. This reaction is the last step in an integrated fuel processor for the conversion of bioresources to liquid fuels. The development of H-ZSM-5 coatings was supported by advanced characterization and testing of catalysts for the determination of property/performance relationships. The selectivity toward the gasoline fraction over H-ZSM-5 coatings with a thickness of 14 μm was similar to that of an industrial ZSM-5 catalyst, however the yield of the undesirable aromatics by-products was reduced by half due to better temperature control in thin catalyst layers. In an attempt to improve the yield of the C₈-C₁₁ hydrocarbons, two postsynthesis modifications have been performed: Ca ion-exchange and desilication by alkaline treatment. The maximum gasoline selectivity over Ca-H-ZSM-5 was observed at a Ca/H ratio of 0.05.