Resid catalytic cracker and catalyst for increased propylene yield

Abstract

A process and catalyst for improving the yield of propylene from residual oil feedstock includes obtaining residual oil feedstock from a vacuum distillation tower. The residual oil feedstock has contaminant metals such as sodium or vanadium. The residual oil feedstock is contacted with a cracking catalyst in a catalytic cracking zone to make products. A ZSM-5 zeolite, a binder, a filler and a metal trap are components of the cracking catalyst. The metal trap has a trapping agent in an outer shell of the catalyst, a trapping agent in the ZSM-5 binder or combinations thereof. After reacting, the cracking catalyst is separated from the products in a separator zone, then regenerated by combusting coke deposited on a surface of the cracking catalyst in an oxygen-containing environment. The cracking catalyst is returned to the catalytic cracking zone. The catalyst with the metal trap is also disclosed.

Description

[0001] Priority claims from earlier national applications [0002] This application claims priority to US Application No. 13 / 300,091, filed November 18, 2011. field of invention [0003] This invention relates to increasing the yield of propylene in refining processes. More specifically, it relates to processes and catalysts for increasing the yield of propylene from high metal content feedstocks. Background of the invention [0004] In a typical refining operation, residual oil ("resid") is produced in a vacuum distillation column. As the demand for petroleum fuels and petrochemicals increases, processing often low-value feedstocks such as residual oils becomes more important. In one method of converting resid into more valuable products, the resid is fed to a resid catalytic cracking zone ("RFCC") to produce higher value naphtha and distillate fuels. Cracking of high boiling resids into lighter hydrocarbon streams such as naphtha or diesel thus yields additional benefit...

AI Technical Summary

Problems solved by technology

Other methods called metal passivation keep the metals in place but reduce their negative impact on the activity and selectivity of the catalyst

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