Reactor staging for slurry hydroconversion of polycyclic aromatic hydrocarbon feeds

Abstract

Methods for processing heavy oil feeds are provided comprising first and second hydroconversion reactors at differing hydroconversion conditions.

1 . A method for processing a heavy oil feedstock, comprising:
 providing a heavy oil feedstock having a 10% distillation point of at least 650° F. (343° C.);   exposing the heavy oil feedstock to a catalyst under first effective slurry hydroconversion conditions in a first hydroconversion reactor to form a first effluent, the first effective slurry hydroconversion conditions comprising a temperature of 840° F. (449° C.) to 1000° F. (538° C.) and a pressure of 1500 psig to 3000 psig;   exposing at least a portion of the first effluent to a catalyst under second effective slurry hydroconversion conditions in a second hydroconversion reactor to form a second effluent; the second effective slurry hydroconversion conditions comprising a temperature of 750° F. (399° C.) to 840° F. (449° C.) and a pressure of 1500 psig to 3000 psig; wherein the temperature of the second effective slurry hydroconversion conditions is lower than the temperature of the first effective slurry hydroconversion conditions.   
     
     
         2 . The method of  claim 1 , further comprising exposing the first effluent to a separator; wherein the separator removes naphtha and distillate fractions from the first effluent prior to a exposing the first effluent to the second hydroconversion reactor. 
     
     
         3 . The method of  claim 2 , wherein the separator comprises a first separator and a second separator; further comprising
 exposing the first effluent to the first separator, thereby forming a first separator bottoms fraction and a first separator light fraction; wherein the first separator bottoms fraction comprises 650° F.+ (343° C.+) hydrocarbons and the first separator light fraction comprises 650° F.− (343° C.−) hydrocarbons and treat gas;   exposing at least a portion of the first separator bottoms fraction to the second hydroconversion reactor;   exposing the first separator light fraction to the second separator, thereby forming a second separator bottoms fraction comprising liquid 160° F.+ (71° C.+) hydrocarbons and a second separator light fraction comprising 160° F.− (71° C.−) hydrocarbons and treat gas; and   exposing at least a portion of the second separator light fraction to the second hydroconversion reactor.   
     
     
         4 . The method of  claim 2 , wherein the separator comprises a first separator and a second separator; further comprising
 exposing the first effluent to the first separator, thereby forming a first separator bottoms fraction comprising liquid 160° F.+ (71° C.+) hydrocarbons and a first separator light fraction comprising 160° F.− (71° C.−) hydrocarbons and treat gas;   exposing at least a portion of the first separator light fraction to the second hydroconversion reactor;   exposing at least a portion of the first separator bottoms fraction to the second separator; thereby forming a second separator bottoms fraction and a second separator light fraction;   
       wherein the second separator bottoms fraction comprises 650° F.+ (343° C.+) hydrocarbons and the second separator light fraction comprises 650° F.− (343° C.−) hydrocarbons and treat gas; and
 exposing at least a portion of the second separator bottoms fraction to the second hydroconversion reactor. 
 
     
     
         5 . The method of  claim 1 , wherein the first effective slurry hydroconversion conditions and the second slurry hydroconversion conditions are effective for a combined conversion of at least 70 wt % of the heavy oil feedstock relative to a conversion temperature of at least 700° F. (371° C.). 
     
     
         6 . The method of  claim 1 , wherein the second effluent has an API gravity of at least 12. 
     
     
         7 . The method of  claim 5 , wherein the second effluent has an API gravity of at least 12. 
     
     
         8 . The method of  claim 1 , wherein the heavy oil feedstock comprises at least one of fluid catalytic cracker main column bottoms, steam cracker tar, and coker gas oil. 
     
     
         9 . The method of  claim 1 , wherein the catalyst comprises MoS 2 . 
     
     
         10 . The method of  claim 1 , wherein the catalyst is present in the heavy oil feedstock at a concentration of 50 wppm to 500 wppm.