Hydroisomerization processes using pre-sulfided catalysts

Abstract

The present application relates to methods for producing a lubricant base oil from a waxy hydrocarbon feed using a pre-sulfided shape selective, intermediate pore size, noble metal-containing molecular sieve catalyst. According to the present invention, a shape selective, intermediate pore size, noble metal-containing molecular sieve catalyst is pre-sulfided to provide a sulfided catalyst, wherein the molar ratio of sulfur to noble metal in the sulfided catalyst is greater than one, and a waxy hydrocarbon feed is hydroisomerized by contacting the waxy hydrocarbon feed with the sulfided catalyst at hydroisomerization conditions, to produce a lubricant base oil.

1 . A method for producing a lubricant base oil from a waxy hydrocarbon feed, the method comprising: 
 a) pre-sulfiding a shape selective, intermediate pore size, noble metal-containing molecular sieve catalyst to provide a sulfided catalyst, wherein the molar ratio of sulfur to noble metal in the sulfided catalyst is greater than one; and    b) hydroisomerizing the waxy hydrocarbon feed by contacting the waxy hydrocarbon feed with the sulfided catalyst at hydroisomerization conditions, to produce a lubricant base oil.    
     
     
         2 . The method of  claim 1 , wherein the molar ratio of sulfur to noble metal in the sulfided catalyst prior to the step of hydroisomerizing is at least 2:1, and wherein the molar ratio of sulfur to noble metal in the sulfided catalyst during the step of hydroisomerizing is at least 3:1.  
     
     
         3 . The method of  claim 1 , wherein the molar ratio of sulfur to noble metal in the sulfided catalyst is at least 3:1.  
     
     
         4 . The method of  claim 1 , wherein the molar ratio of sulfur to noble metal in the sulfided catalyst is at least 5:1.  
     
     
         5 . The method of  claim 1 , wherein the waxy hydrocarbon feed is selected from the group consisting of gas oil, lubricating oil stock, synthetic oil, Fischer-Tropsch derived wax, oligomerized Fischer-Tropsch derived olefins, foots oil, slack wax, de-oiled wax, normal alpha olefin wax, microcrystalline wax, and mixtures thereof.  
     
     
         6 . The method of  claim 5 , wherein the waxy hydrocarbon feed is a Fischer-Tropsch derived wax.  
     
     
         7 . The method of  claim 1 , wherein the molecular sieve has channel diameters in the range of from about 4.0 to 7.1 Å.  
     
     
         8 . The method of  claim 1 , wherein the molecular sieve is non-zeolitic.  
     
     
         9 . The method of  claim 8 , wherein the catalyst is a SAPO catalyst.  
     
     
         10 . The method of  claim 9 , wherein the SAPO catalyst is selected from the group consisting of SAPO-11, SAPO-31, and SAPO-41.  
     
     
         11 . The method of  claim 1 , wherein the noble metal is selected from the group consisting of platinum, palladium, and mixtures thereof.  
     
     
         12 . The method of  claim 1 , wherein the pre-sulfiding step comprises contacting the catalyst with a sulfur-containing species in the presence of hydrogen, the sulfur-containing species being selected from the group consisting of hydrogen sulfide, carbon disulfide, and a mercaptan.  
     
     
         13 . The method of  claim 12 , wherein the waxy hydrocarbon feed contains less than about 10 ppm sulfur.  
     
     
         14 . The method of  claim 1 , wherein the waxy hydrocarbon feed is a sulfur spiked feedstock.  
     
     
         15 . The method of  claim 1 , wherein the hydroisomerization conditions include a total pressure of between about 150 and 1,000 psig.  
     
     
         16 . The method of  claim 15 , wherein the hydroisomerization conditions include a total pressure of between about 150 and 500 psig.  
     
     
         17 . The method of  claim 16 , wherein the hydroisomerization conditions include a total pressure of between about 150 and 300 psig.  
     
     
         18 . The method of  claim 15 , wherein the hydroisomerization conditions include a total pressure of between about 500 and 1,000 psig.  
     
     
         19 . The method of  claim 1 , wherein between about 40 and 95 weight percent of the lubricant base oil has a boiling point of between about 650 and 1400° F.  
     
     
         20 . The method of  claim 1 , wherein the lubricant base oil has a viscosity index between about 140 and 190.  
     
     
         21 . The method of  claim 1 , wherein the lubricant base oil has a pour point between about −5 and −60° C.  
     
     
         22 . The method of  claim 1 , wherein the lubricant base oil has a viscosity at 100° C. of greater than 3 cSt.  
     
     
         23 . The method of  claim 1 , further comprising solvent dewaxing at least a portion of the lubricant base oil, thereby removing a slack wax.  
     
     
         24 . The method of  claim 23 , further comprising hydroisomerizing the slack wax with the waxy hydrocarbon feed.  
     
     
         25 . A process for producing a lubricant base oil comprising: 
 a) contacting a shape selective, intermediate pore size, noble-metal containing molecular sieve with a sulfur-containing species to provide a pre-sulfided catalyst, wherein the molar ratio of sulfur to noble metal in the pre-sulfided catalyst is greater than one;    b) providing a Fischer-Tropsch waxy hydrocarbon feed;    c) contacting the Fischer-Tropsch waxy hydrocarbon feed with the pre-sulfided catalyst to hydroisomerize the feed; and    d) isolating a lubricant base oil.    
     
     
         26 . The process of  claim 25 , wherein the lubricant base oil has a pour point between about −5 and −60° C. and a viscosity index at 100° C. of greater than 3 cSt.