PROCESS TO PRODUCE PROPYLENE FROM REFINERY DRY GAS

The process converts ethylene in a dilute ethylene (dry gas) stream that may be derived from an FCC product to propylene. The process includes an oligomerization step to convert ethylene in the dilute ethylene stream to heavier olefins, and a second reaction step to convert the heavier olefins to propylene. The oligomerization catalyst may be an amorphous silica-alumina base with a Group VIII and/or VIB metal. The catalyst is resistant to feed impurities such as hydrogen sulfide, carbon oxides, hydrogen and ammonia. At least 50 wt-% of the ethylene in the dilute ethylene stream can be converted to C4+ olefins and recycled to the FCC for cracking to propylene.