Ionic liquid treatment of vacuum slop cut to increase hydrocracking feed

Abstract

A process and apparatus for increasing vacuum gas oil recovery from a vacuum column are described. The process includes separating a residue crude oil stream from a crude oil separation column in a vacuum column into at least one vacuum gas oil fraction, and a contaminant-rich slop fraction containing at least one contaminant; contacting the contaminant-rich slop fraction with a lean ionic liquid in a contaminant removal zone to produce a mixture comprising a contaminant-lean slop fraction and a rich ionic liquid comprising at least a portion of the at least one contaminant; and separating the mixture to produce a treated slop effluent comprising the contaminant-lean slop fraction and a rich ionic liquid effluent comprising the rich ionic liquid.

What is claimed is: 
     
         1 . A process for increasing vacuum gas oil recovery from a vacuum column comprising:
 separating a residue crude oil stream from a crude oil separation column in a vacuum column into at least one vacuum gas oil fraction, and a contaminant-rich slop fraction containing at least one contaminant;   contacting the contaminant-rich slop fraction with a lean ionic liquid in a contaminant removal zone to produce a mixture comprising a contaminant-lean slop fraction and a rich ionic liquid comprising at least a portion of the at least one contaminant; and   separating the mixture to produce a treated slop effluent comprising the contaminant-lean slop fraction and a rich ionic liquid effluent comprising the rich ionic liquid.   
     
     
         2 . The process of  claim 1  further comprising introducing the treated slop effluent into a secondary conversion zone comprising at least one of a hydrocracking or a hydrotreating zone and a fluid catalytic cracking zone. 
     
     
         3 . The process of  claim 2  further comprising:
 combining the treated slop effluent with the at least one vacuum gas oil fraction to form a combined fraction before introducing the treated slop effluent into the secondary conversion zone. 
 
     
     
         4 . The process of  claim 1  further comprising regenerating the rich ionic liquid effluent to remove at least a portion of the at least one contaminant from the rich ionic liquid effluent forming a regenerated ionic liquid and an extract stream containing at least the portion of the at least one contaminant. 
     
     
         5 . The process of  claim 4  further comprising separating the regenerated ionic liquid from the extract stream. 
     
     
         6 . The process of  claim 5  further comprising recycling the regenerated ionic liquid to the treatment zone. 
     
     
         7 . The process of  claim 5  wherein separating the residue crude oil stream from the crude oil separation column in the vacuum column into the at least one vacuum gas oil fraction, and the contaminant-rich slop fraction comprises separating the residue crude oil stream from the crude oil separation column in the vacuum column into the at least one vacuum gas oil fraction, the contaminant-rich slop fraction, and a vacuum residue fraction; and
 further comprising combining the extract stream with the vacuum residue fraction. 
 
     
     
         8 . The process of  claim 7  further comprising introducing the combined extract stream and vacuum residue fraction to a delayed coker zone. 
     
     
         9 . The process of  claim 1  wherein the contaminant-rich slop fraction comprises between about 5 wt % to about 30 wt % of a total of the at least one vacuum gas oil fractions. 
     
     
         10 . The process of  claim 1  wherein the at least one vacuum gas oil fraction comprises a light vacuum gas oil fraction and a heavy vacuum gas oil fraction. 
     
     
         11 . The process of  claim 1  wherein the contaminant-rich slop fraction has a boiling point in a range of about 490° C. to about 565° C. 
     
     
         12 . The process of  claim 1  wherein the ionic liquid comprises an organic cation and an anion, and wherein the organic cation is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         where R 1 -R 21  are independently selected from C 1 -C 20  hydrocarbons, C 1 -C 20  hydrocarbon derivatives, halogens, and H. 
       
     
     
         13 . The process of  claim 1 , wherein the ionic liquid comprises an organic cation and an anion, and wherein the anion comprises at least one of a carboxylate, an acetate, a tosylate, a cyanate, a halide, a sulfate, a hydrogen sulfate, a sulfonate, a sulfonyl imide, a phosphate, a borate, a carbonate, or a heterocyclic anion. 
     
     
         14 . A process for increasing the vacuum gas oil recovery from a vacuum column comprising:
 separating a residue crude oil stream from a crude oil separation column in a vacuum column into at least one vacuum gas oil fraction, a contaminant-rich slop fraction containing at least one contaminant, and a vacuum residue fraction;   contacting the contaminant-rich slop fraction with a lean ionic liquid in a contaminant removal zone to produce a mixture comprising a contaminant-lean slop fraction and a rich ionic liquid comprising at least a portion of the at least one contaminant;   separating the mixture to produce a treated slop effluent comprising the contaminant-lean slop fraction and a rich ionic liquid effluent comprising the rich ionic liquid;   introducing the treated slop effluent into a secondary conversion zone comprising at least one of a hydrocracking zone, a fluid catalytic cracking zone, and a VGO hydrotreating zone; and   regenerating the rich ionic liquid effluent to remove at least a portion of the at least one contaminant from the rich ionic liquid effluent forming a regenerated ionic liquid and an extract stream containing at least the portion of the at least one contaminant.   
     
     
         15 . The process of  claim 14  further comprising:
 combining the treated slop effluent with the at least one vacuum gas oil fraction to form a combined fraction before introducing the treated slop effluent into the secondary conversion zone. 
 
     
     
         16 . The process of  claim 14  further comprising separating the regenerated ionic liquid from the extract stream. 
     
     
         17 . The process of  claim 14  further comprising recycling the regenerated ionic liquid to the treatment zone. 
     
     
         18 . The process of  claim 14  wherein the contaminant-rich slop fraction comprises between about 5 wt % to about 30 wt % of a total of the at least one vacuum gas oil fractions. 
     
     
         19 . The process of  claim 14  wherein the contaminant-rich slop fraction has a boiling point in a range of about 490° C. to about 565° C. 
     
     
         20 . An apparatus for increasing vacuum gas oil recovery comprising:
 a crude oil separation column having an inlet and at least a bottom outlet;   a vacuum column having an inlet and at least an upper and a lower outlet, the inlet of the vacuum column being in fluid communication with the bottom outlet of the crude oil separation column;   a contaminant removal zone having an inlet and an outlet, the inlet of the contaminant removal zone being in fluid communication with the lower outlet of the vacuum column;   a secondary conversion zone having an inlet and an outlet, the inlet of the secondary conversion zone being in fluid communication with the upper outlet of the vacuum column and the outlet of the contaminant removal zone.