Process for fluid catalytic cracking of heavy oil

Abstract

Provided is a process for fluid catalytic cracking of a heavy oil by contacting the oil with a catalyst at an elevated temperature for a short period of time to produce light olefins such as propylene and butene. The process includes contacting the heavy oil with a catalyst containing as a constituent thereof a fluid catalytic cracking catalyst with a weight ratio (Wmat/Wusy) of an active matrix weight (Wmat) to an ultrastable Y type zeolite weight (Wusy) of 0 to 0.3, under conditions where the reaction zone outlet temperature is from 580 to 630° C., the catalyst/oil ratio is from 15 to 40 weight/weight and the residence time of hydrocarbon in the reaction zone is from 0.1 to 1.0 second.

1 . A process for fluid catalytic cracking of a heavy oil to produce light olefins, comprising contacting the heavy oil with a catalyst comprising as a constituent thereof a fluid catalytic cracking catalyst with a weight ratio (Wmat/Wusy) of an active matrix weight (Wmat) to an ultrastable Y type zeolite weight (Wusy) of 0 to 0.3, under conditions where the reaction zone outlet temperature is from 580 to 630° C., the catalyst/oil ratio is from 15 to 40 weight/weight and the residence time of hydrocarbon in the reaction zone is from 0.1 to 1.0 second. 
     
     
         2 . The process for fluid-catalytic cracking of heavy oil according to  claim 1  wherein the catalyst comprises 50 to 95 percent by mass of the fluid catalytic cracking catalyst and 5 to 50 percent by mass of an additive comprising a shape selectivity zeolite. 
     
     
         3 . The process for fluid-catalytic cracking of heavy oil according to  claim 1  wherein the content of the ultrastable Y type zeolite in the fluid catalytic cracking catalyst is from 5 to 50 percent by mass. 
     
     
         4 . The process for fluid-catalytic cracking of heavy oil according to  claim 1  wherein the ultrastable Y type zeolite has a crystal lattice constant of 24.20 to 24.60 Å. 
     
     
         5 . The process for fluid-catalytic cracking of heavy oil according to  claim 1  wherein the content of a rare-earth metal oxide in the fluid catalytic cracking catalyst is 1.5 percent by mass or less. 
     
     
         6 . The process for fluid-catalytic cracking of heavy oil according to  claim 1  wherein a fluid catalytic cracking reactor having a downflow type reaction zone, a gas-solid separation zone, a stripping zone and a catalyst regeneration zone is used.