CONVERSION OF METHANOL TO C₂-C₃ ALKENES ON MODIFIED HIGH-SILICA ZSM-5-TYPE ZEOLITES

Abstract To increase the selectivity for C₂-C₃ alkenes, catalysts based on ZSM-5 zeolite, modified with zinc, cobalt, gadolinium, and zirconium, were obtained using the impregnation method. The conversion of methanol to hydrocarbons was carried out in a flow reactor with a fixed catalyst bed in the temperature range of 300-350°C, under atmospheric pressure, in a nitrogen flow. It has been shown that H-ZSM-5 has low selectivity for C₂-C₃ alkenes (24.0%). The modified H-ZSM-5 with zinc, gadolinium, and zirconium improves selectivity for C₂-C₃ alkenes (52.6% - 63.6%) and reduces selectivity for C₁-C₅ alkenes (from 39.1% to 17.2% - 25.7%). The highest selectivity for C₃ alkenes (65.5% - 68.7%) and propylene (38.4% - 42.2%) is achieved with the two-component modification of the zeolite on Gd-Zr-H-ZSM-5 and Zn-Zr-H-ZSM-5 samples.