| 摘要 |
Disclosed is a method for preparing paraxylene with co-production of propylene with high selectivity. Firstly, the raw materials toluene and methanol and/or dimethyl ether are contacted with a catalyst and reacted in a reaction system, after the resultant product is separated via a separation system, the C2 - component therein which is rich in ethylene (hydrocarbons with less than or equal to two carbon atoms and CO, CO2 and H2) is returned to the reaction system to continue the reaction, the C6 + component (aromatic hydrocarbons with greater than or equal to six carbon atoms) is further separated so as to obtain the paraxylene, and the C3 component (propylene and propane with equal to three carbon atoms) is further separated so as to obtain the propylene.In the method, by coupling two reaction processes, i.e. the alkylation reaction of toluene and methanol and/or dimethyl ether, and the alkylation reaction of ethylene and methanol and/or dimethyl ether, under a catalyst, the C2 - component which is rich in ethylene in the by-product of the reaction for preparing paraxylene by the alkylation of toluene and methanol and/or dimethyl ether is reprocessed and is performed the alkylation reaction with methanol and/or dimethyl ether with, thus obtaining paraxylene with co-production of propylene in high selectivity. |
