Fuels and lubricants using layered bed catalysts in hydrotreating waxy feeds, including fischer-tropsch wax, plus solvent dewaxing

Abstract

Waxy hydrocarbon feedstocks are contacted with a hydrocracking catalyst and the effluent then contacted with an intermediate pore size molecular sieve hydroisomerization catalyst. The effluent from the hydroisomerization is fractionated to provide a heavy fraction and a middle distillate fuel. At least a portion of the heavy fraction is dewaxed to provide a high quality lubricant base oil with a high viscosity index and a low pour point.

What is claimed is:  
     
         1 . A process for treating a waxy hydrocarbon feedstock comprising the steps of: 
 a) contacting the feedstock with a hydrocracking catalyst in a hydrocracking zone, producing a hydrocracking effluent;    b) contacting the hydrocracking effluent with an intermediate pore size molecular sieve hydroisomerization catalyst in a hydroisomerization zone, producing a hydroisomerization effluent;    c) fractionating the hydroisomerization effluent, providing a heavy fraction and a middle distillate fuel; and    d) dewaxing at least a portion of the heavy fraction to provide a lubricant base oil having a viscosity index of greater than 130, a pour point of less than −15° C., and a viscosity of greater than 3 cSt at 100° C.    
     
     
         2 . A process according to  claim 1 , wherein the lubricant base oil has a viscosity index of greater than 140, a pour point of less than −15° C., and a viscosity of greater than 4 cSt at 100° C.  
     
     
         3 . A process according to  claim 1 , wherein the lubricant base oil has a viscosity index of greater than 150, a pour point of less than −15° C., and a viscosity of greater than 5 cSt at 100° C.  
     
     
         4 . A process according to  claim 1 , wherein the total hydrocracking effluent is contacted with the hydroisomerization catalyst in a hydroisomerization zone.  
     
     
         5 . A process according to  claim 1 , wherein the hydrocracking catalyst and the hydroisomerization catalyst are layered in a single reaction zone in a single reactor.  
     
     
         6 . A process according to  claim 1 , wherein the hydrocracking catalyst and the hydroisomerization catalyst are layered in a single reaction zone in close-coupled series reactors with no product withdrawal or feed inlet between reactors.  
     
     
         7 . A process according to  claim 1 , wherein a portion of the heavy fraction is recycled to the hydrocracking zone.  
     
     
         8 . A process according to  claim 1 , wherein the waxy hydrocarbon feedstock comprises a Fischer Tropsch derived 650° F.+feed.  
     
     
         9 . A process according to  claim 1 , wherein the waxy hydrocarbon feedstock comprises greater than 20 weight % 900° F.+components.  
     
     
         10 . A process according to  claim 1 , wherein the waxy hydrocarbon feedstock comprises greater than 85 wt % 650° F.+components and wherein less than 60 weight % of the 650° F.+components are converted to 650° F.−products.  
     
     
         11 . A process for treating a 650° F.+waxy hydrocarbon feedstock comprising the steps of: 
 a) contacting the feedstock with a hydrocracking catalyst in a hydrocracking zone, producing a hydrocracking effluent;  
 b) contacting the hydrocracking effluent with an intermediate pore size molecular sieve hydroisomerization catalyst in a hydroisomerization zone, producing a hydroisomerization effluent;  
 c) fractionating the hydroisomerization effluent, providing a heavy fraction and a middle distillate fuel; and  
 d) dewaxing at least a portion of the heavy fraction to provide a lubricant base oil having a viscosity index of greater than 130, a pour point of less than −15° C., and a viscosity of greater than 3 cSt at 100° C., and wherein less than 60 weight % of the 650° F.+components are converted to 650° F.−products.  
 
     
     
         12 . A process according to  claim 11 , wherein the lubricant base oil has a viscosity index of greater than 140, a pour point of less than −15° C., and a viscosity of greater than 4 cSt at 100° C.  
     
     
         13 . A process according to  claim 11 , wherein the lubricant base oil has a viscosity index of greater than 150, a pour point of less than −15° C., and a viscosity of greater than 5 cSt at 100° C.  
     
     
         14 . A process according to  claim 11 , wherein the hydrocracking catalyst and the hydroisomerization catalyst are layered in a single reaction zone in a single reactor.  
     
     
         15 . A process according to  claim 11 , wherein the 650° F.+waxy hydrocarbon feedstock is derived from a Fischer Tropsch process.  
     
     
         16 . A process according to  claim 15 , wherein the 650° F.+waxy hydrocarbon feedstock is not hydrotreated prior to hydrocracking.  
     
     
         17 . A process according to  claim 11 , wherein the 650° F.+waxy hydrocarbon feedstock comprises greater than 20 weight % 900° F.+components.  
     
     
         18 . A process according to  claim 11 , wherein the 650° F.+waxy hydrocarbon feedstock comprises greater than 85 wt % 650° F.+components.  
     
     
         19 . A process according to  claim 11 , wherein the hydrocracking catalyst and the hydroisomerization catalyst are layered in a single reaction zone in close-coupled series reactors with no product withdrawal or feed inlet between reactors.  
     
     
         20 . A process according to  claim 11 , wherein a portion of the heavy fraction is recycled to the hydrocracking zone.  
     
     
         21 . A process for treating a 650° F.+waxy hydrocarbon feedstock comprising the steps of: 
 a) contacting the feedstock with a hydrocracking catalyst in a hydrocracking zone, producing a hydrocracking effluent;  
 b) contacting the hydrocracking effluent with an intermediate pore size molecular sieve hydroisomerization catalyst in a hydroisomerization zone, producing a hydroisomerization effluent;  
 c) fractionating the hydroisomerization effluent, providing a heavy fraction and a middle distillate fuel; and  
 d) dewaxing at least a portion of the heavy fraction to provide a lubricant base oil having a viscosity index of greater than 130, a pour point of less than −15° C., and a viscosity of greater than 4 cSt at 100° C., and wherein the 650° F.+waxy hydrocarbon feedstock comprises greater than 20 weight% 900° F.+components.  
 
     
     
         22 . A process according to  claim 21 , wherein the 650° F.+waxy hydrocarbon feedstock comprises greater than 40 weight % 900° F.+components.  
     
     
         23 . A process according to  claim 21 , wherein the 650° F.+waxy hydrocarbon feedstock comprises greater than 60 weight % 900° F.+components.  
     
     
         24 . A process according to  claim 21 , wherein the lubricant base oil has a viscosity index of greater than 140, a pour point of less than −15° C., and a viscosity of greater than 4 cSt at 100° C.  
     
     
         25 . A process according to  claim 21 , wherein the lubricant base oil has a viscosity index of greater than 150, a pour point of less than −15° C., and a viscosity of greater than 5 cSt at 100° C.  
     
     
         26 . A process according to  claim 21 , wherein the hydrocracking catalyst and the hydroisomerization catalyst are layered in a single reaction zone in a single reactor.  
     
     
         27 . A process according to  claim 21 , wherein the 650° F.+waxy hydrocarbon feedstock is derived from a Fischer Tropsch process.  
     
     
         28 . A process according to  claim 21 , wherein the hydrocracking catalyst and the hydroisomerization catalyst are layered in a single reaction zone in close-coupled series reactors with no product withdrawal, or feed inlet between reactors.  
     
     
         29 . A process according to  claim 21 , wherein a portion of the heavy fraction is recycled to the hydrocracking zone.  
     
     
         30 . A process according to  claim 23 , wherein the lubricant base oil has a viscosity index of greater than 140, a pour point of less than −15° C., and a viscosity of greater than 4 cSt at 100° C.  
     
     
         31 . A process according to  claim 23 , wherein the lubricant base oil has a viscosity index of greater than 150, a pour point of less than −15° C., and a viscosity of greater than 5 cSt at 100° C.  
     
     
         32 . A process according to  claim 21 , wherein less than 60 weight % of the 650° F.+components of the 650° F.+waxy hydrocarbon feed are converted to 650° F.−products.