Effect of Feedstock and Gas Atmosphere Composition on Selectivity and Distribution of Hydrocarbon Groups in Gasoline Synthesis from Oxygenates

Gasoline has been synthesized from oxygenates (dimethyl ether and methanol) on a HZSM-5 zeolite catalyst, modified by palladium and zinc, in a micropilot unit operating in the continuous recycle flow mode. The influence of the gas atmosphere composition—synthesis gas, hydrogen, and methane—on the gasoline selectivity, and on-stream stability of the catalyst has been determined for dimethyl ether (DME) used as a feedstock. The hydrocarbon composition and the carbon distribution in the products have been compared using DME and methanol as the feedstock in the synthesis-gas atmosphere. It has been shown that the higher gasoline selectivity production in the case of methanol is due to the higher concentration of aromatic hydrocarbons, which is achieved by decreasing the intensity of their dealkylation.