PROCESS FOR PRODUCING OLEFINS FROM OXYGENATE

摘要

There is provided a process for converting methanol and/or dimethyl ether to a product containing olefin, e.g., C2 to C4 olefins, C9+ aromatics and non-C9+ aromatics which comprises: (1) contacting a feed which contains methanol and/or dimethyl ether with a catalyst comprising a porous crystalline material, said contacting step being conducted in the presence of aromatics comprising C9 or C9+ aromatic compound produced in said process under conversion conditions including a temperature of 350 DEG C to 480 DEG C and a methanol partial pressure in excess of 10 psia (70 kPa), said porous crystalline material having a Diffusion Parameter for 2,2-dimethylbutane of about 0.1 sec<-1> to about 20 sec<-1> when measured at a temperature of 120 DEG C and a 2,2-dimethylbutane pressure of 60 torr (8 kPa), and the aromatics being capable of alkylation by the methanol and/or dimethyl ether under said conversion conditions to provide a stream which contains C2 to C4 olefins and C9 or C9+ aromatic compound; (2) separating said stream to form a substantially C2 to C4 olefin product stream and a substantially C9 or C9+ aromatic compound stream; and 3) recycling at least a portion of said substantially C9 or C9+ aromatic compound stream to step (1).