Influence of spectral and textural characteristics and acidity of MFI zeolite on activity of catalysts for dimethyl ether conversion to hydrocarbons

Abstract

Comparative data obtained by studying the synthesis of С₅₊ hydrocarbons from dimethyl ether (DME) on catalysts using MFI zeolites available from different manufacturers are presented. It has been shown that MFI zeolite samples substantially differ in their acidic properties and structural, morphological, and textural characteristics. The catalysts based on different MFI zeolites also noticeable differ in the yield and chemical composition of С₅₊ hydrocarbons. By switching from the stand-alone operation of a DME conversion reactor to the joint operation of two reactors for synthesis of oxygenates (DME and/or methanol) from synthesis gas and synthesis of hydrocarbons from oxygenates connected by a single circuit, high selectivity for hydrocarbons of the gasoline fraction is achieved with the catalyst based on the MFI zeolite, for which the bands characteristic of Н₃О⁺ acid sites are observed in diffuse reflectance IR spectra.