PURGE STREAMS IN PARAXYLENE PRODUCTION

摘要

In a process for producing para-xylene, a hydrocarbon feed comprising xylenes and ethylbenzene is supplied to a para-xylene extraction system, where a para-xylene-rich stream is recovered from the feed to leave at least one para-xylene-depleted stream. At least a portion of the para-xylene-depleted stream is isomerized at least partially in the liquid phase to produce an isomerized stream having a higher para-xylene concentration than the para- xylene-depleted stream. At least a portion of the isomerized stream is then recycled to the para-xylene extraction system. To control ethylbenzene build-up in the process, a purge stream is removed from the para-xylene-depleted stream and/or the isomerized stream and is subjected to one or more chemical processing steps to produce benzene and/or para-xylene.