Hydroprocessing of high density cracked fractions

Abstract

Systems and methods are provided for upgrading a heavy cracked feedstock in a single reaction stage under fixed bed hydroprocessing conditions, including exposing the feedstock to a first bulk or supported mixed metal catalyst comprising Ni and Mo; exposing the feedstock to a second bulk or supported mixed metal catalyst comprising Ni and W; and exposing the feedstock to a third catalyst comprising a zeolite-based hydrocracking catalyst.

1 . A process for upgrading a heavy cracked feedstock, comprising:
 providing a feedstock comprising a density at 15° C. of 1.06 g/cm 3  or more, at least 50 wt % of one or more 343° C.+ cracked fractions, and a sulfur content of 0.8 to 5.0 wt % sulfur;   in a single reaction stage under fixed bed hydroprocessing conditions, exposing the feedstock to a first bulk or supported mixed metal catalyst comprising Ni and Mo; exposing the feedstock to a second bulk or supported mixed metal catalyst comprising Ni and W; and exposing the feedstock to a third catalyst comprising a zeolite-based hydrocracking catalyst.   
     
     
         2 . The process of  claim 1 , wherein the zeolite-based hydrocracking catalyst comprises a Group VIII noble metal. 
     
     
         3 . The process of  claim 2 , wherein the zeolite-based hydrocracking catalyst comprises 0.5 to 2.5 wt % Pt. 
     
     
         4 . The process of  claim 1 , wherein the third catalyst further comprises an aromatic saturation catalyst comprising Pd, Pt, or a combination thereof on an aluminosilicate support. 
     
     
         5 . The process of  claim 4 , wherein the aromatic saturation catalyst comprises Pd and Pt in a wt % ratio of about 3:1 Pd to Pt. 
     
     
         6 . The process of  claim 4 , wherein the aromatic saturation catalyst comprises 2.0 wt % Pt. 
     
     
         7 . The process of  claim 1 , wherein the zeolite exhibits a faujasite (FAU) framework type. 
     
     
         8 . The process of  claim 1 , wherein the feedstock comprises a density at 15° C. of 1.1 g/cm 3  or more, a T 10  of at least 343° C. and a T 90  of at least 475° C.; and a sulfur content of 3.0 wt % to 5.0 wt %. 
     
     
         9 . The process of  claim 8 , wherein the feedstock comprises a de-asphalted heavy cracked feedstock. 
     
     
         10 . The process of  claim 1 , wherein the fixed bed hydroprocessing conditions include a temperature of 300° C. to 400° C., a pressure of 1500 psig to 3000 psig, a hydrogen treat gas rate of 2,000 scf/bbl to 12,000 scf/bbl, and a LHSV of 0.2 h −1  to 1.5 h −1 . 
     
     
         11 . A system for processing a cracked feedstock comprising:
 a hydroprocessing reactor comprising a hydroprocessing inlet, and a hydroprocessing outlet, and a fixed bed comprising a first bulk or supported mixed metal catalyst comprising Ni and Mo; a second bulk or supported mixed metal catalyst comprising Ni and W; and a third catalyst comprising a zeolite-based hydrocracking catalyst;   wherein the hydroprocessing inlet is designed to receive a feedstock comprising a density at 15° C. of 1.06 g/cm 3  or more, at least 50 wt % of one or more 343° C.+ cracked fractions, and a sulfur content of 1.0 to 5.0 wt % sulfur; and   wherein the fixed bed is oriented such that the feedstock contacts the first catalyst, second catalyst, and third catalyst sequentially.