Conversion of dimethyl ether and methanol to hydrocarbons over zeolites with BEA, MRE, and MWW structures

Abstract

The catalytic properties of zeolite-based catalysts BEA/Al₂O₃, MCM-22/Al₂O₃, MRE/Al₂O₃, and MFI/Al₂O₃ were compared in the conversion of dimethyl ether (DME) and methanol into hydrocarbons at 340 °C under 0.1 MPa (for DME) and 10.0 MPa (for methanol). Catalysts BEA/Al₂O₃, MCM-22/Al₂O₃, and MFI/Al₂O₃ with comparable total acidity demonstrated similar activity. However, due to differences in zeolite structure, catalyst stability and product distribution varied. The MCM-22 zeolite with “super-cages” enabled a C₅₊ liquid hydrocarbon yield of 62 wt% under atmospheric pressure. BEA/Al₂O₃, with a high fraction of mesopores, facilitated the formation of heavier hydrocarbons C₁₄–C₁₆, components of aviation fuel. The MRE-based catalyst exhibited the lowest acidity and activity but showed high selectivity towards C₂–C₄ olefins and operational stability.