Catalytic synthesis of C$_2$-C$_4$-alkenes from dimethyl ether

Abstract

In the study, the effect of the volumetric velocity of the initial gaseous mixture on the catalytic properties of Zn-Zr-Cu/HSZ/Al$_2$O$_3$ in the conversion of dimethyl ether to olefins was studied. When the volumetric rate is increased by 5 times, the conversion of dimethyl ether decreases from 96.5 to 40.7 %, the total selectivity for C$_2$=-C$_4$=olefins decreases from 59.0 to 75.5 mas.%, at the same time, the yield of the by-products of the reaction - C$_2$ + paraffin is reduced. A decrease in the reaction temperature at the equal conversion of dimethyl ether leads to an increase in selectivity for both ethylene and propylene due to a decrease in the formation of methane and C$_2$+paraffin in the reaction products. Thus, in copper-containing zeolite catalysts, lower olefins than dimethyl ether provide higher conversion of raw material and higher selectivity of olefin formation (up to 90 mas. %.). Also, changing the initial raw material composition and regime parameters allows a significant change in the ratio of olefins to each other.