Process to continuously prepare two or more base oil grades and middle distillates

Abstract

Process to prepare simultaneously two or more base oil grades and middle distillates from a de-asphalted oil or a vacuum distillate feed or their mixtures by performing the following steps: (a) hydrocracking the feed, thereby obtaining an effluent; (b) distillation of the effluent as obtained in step (a) into one or more middle distillates and a residue boiling substantially above 340° C.; (c) separating, by means of a further distillation step said residue into a light base oil precursor fraction and a heavy base oil precursor fraction; (d) reducing the pour point of each separate base oil precursor-fraction iri″two simultaneously and parallel operated catalytic dewaxing reactors obtaining a first and second dewaxed oil; (e) hydrotreating the first dewaxed oil as obtained when dewaxing the heavy base oil precursor fraction in step (d); (f) isolating from the second dewaxed oil from the light base oil precursor fraction from step (d) and the hydrotreated oil from step (e) two or more base oil grades.

1 . A process for making a base oil product, said process comprises the following steps: 
 (a) hydrocracking a mineral crude derived feed, thereby obtaining an effluent;    (b) distilling said effluent as obtained in step (a) into at least one middle distillates product and a residue boiling substantially above 340° C.;    (c) separating, said residue into a light base oil precursor fraction and a heavy base oil precursor fraction;    (d) reducing the pour point of said heavy base oil precursor fraction by catalytic dewaxing to obtain a first dewaxed oil and reducing the pour point of said light base oil precursor fraction by catalytic dewaxing to obtain a second dewaxed oil;    (e) hydrotreating said first dewaxed oil as obtained from the catalytic dewaxing of said heavy base oil precursor fraction in step (d) to provide a hydrotreated oil; and    (f) isolating from the second dewaxed oil and from the hydrotreated oil two or more base oil grades.    
     
     
         2 . A process according to  claim 1 , wherein more than 80 wt % of the residue boils above 340° C. and wherein between 10 and 40 wt % of the combined first dewaxed oil and second dewaxed oil boils in the heavy gas oil range of between 350° C. to 400° C.  
     
     
         3 . A process according to  claim 2 , wherein between 20 and 40 wt % of the heavy base oil precursor fraction as obtained in step (c) is recycled to step (a).  
     
     
         4 . A process according to  claim 1 , wherein the 10 wt % recovery point of the heavy base oil precursor fraction as obtained in step (c) is between 420 and 550° C.  
     
     
         5 . A process according to  claim 4 , wherein the 10 wt % recovery point of the heavy base oil precursor fraction as obtained in step (c) is between 440 and 520° C.  
     
     
         6 . A process according to  claim 1 , further comprising adding a partly isomerized paraffin wax as obtained in a Fischer-Tropsch process and boiling in the heavy base oil precursor fractions boiling range to said heavy base oil precursor fraction prior to its catalytic dewaxing.  
     
     
         7 . A process according to  claim 1 , wherein the weight hourly space velocity in the catalytic dewaxing step (d) for processing the light base oil precursor fraction is higher than the weight hourly space velocity in the catalytic dewaxing step (d) for processing the heavy base oil precursor fraction.  
     
     
         8 . A process according to  claim 7 , wherein the weight hourly space velocity in the catalytic dewaxing step (d) for processing the light base oil precursor fraction is between 1 and 5 kg/l/hr.  
     
     
         9 . process according to  claim 8 , wherein the pressure at which the light base oil precursor fraction is dewaxed in step (d) is between 15 and 65 bars and the pressure at which the heavy base oil precursor fraction is dewaxed is between 100 and 250 bars.  
     
     
         10 . A process according to  claim 9 , wherein step (f) is performed on a mixture of the second dewaxed oil as obtained when processing the light base oil precursor fraction and the hydrotreated oil.  
     
     
         11 . A process for making multiple grades of base oil products, wherein said process comprises: 
 hydrocracking a vacuum gas oil to yield a hydrocracker effluent;    separating said hydrocracker effluent into a middle distillate fraction and a residue fraction of which said residue fraction a predominant portion thereof boils above 340° C.;    separating said residue fraction into a light base oil precursor fraction and a heavy base oil precursor fraction;    reducing the pour point of said heavy base oil precursor fraction by catalytically dewaxing thereof to yield a first dewaxed oil;    reducing the pour point of said light base oil precursor fraction by catalytically dewaxing thereof to yield a second dewaxed oil;    hydrotreating said first dewaxed oil to provide a hydrotreated oil; and    separating said hydrotreated oil and said second dewaxed oil into at least two base oil products of different base oil grades.    
     
     
         12 . A process as recited in  claim 11 , wherein more than 80 wt % of said residue fraction has a boiling temperature above 340° C.  
     
     
         13 . A process as recited in  claim 12 , wherein from between 10 to 40 wt % of the total of said hydrotreated oil and said second dewaxed oil boils in the heavy gas oil boiling range of from 350° C. to 400° C.  
     
     
         14 . A process as recited in  claim 13 , wherein the catalytic dewaxing process conditions of the step for reducing the pour point of said light base oil precursor fraction includes a weight hourly space velocity (WHSV) in the range of from 1 to 5 kg/l/hr and a second catalytic dewaxing pressure in the range of from 15 to 65 bars, and the catalytic dewaxing process conditions of the step for reducing the pour point of said heavy base oil precursor fraction includes a weight hourly space velocity (WHSV) in the range of from 0.2 to 5 kg/l/hr and a first catalytic dewaxing pressure in the range of from 100 to 250 bars.