Process to Prepare a Lubricating Base Oil

Abstract

Process to prepare a base oil having an paraffin content of between 75 and 95 wt % by subjecting a mixture of a Fischer-Tropsch derived feed and a petroleum derived feed to a catalytic pour point reducing treatment.

1 . A process to prepare a base oil having a paraffin content of between 75 and 95 wt % the process comprising subjecting a mixture of a hydroisomerized Fischer-Tropsch wax and a petroleum derived feed to a catalytic pour point reducing treatment, wherein the petroleum derived feed has an aromatic content of between 0 and 20 wt % and a naphthenic compound content of between 15 and 90 wt % and wherein the fraction of petroleum derived feed in the mixture is higher than 5 wt % and lower than 50 wt %.  
   
   
       2 . The process of  claim 1 , wherein the petroleum derived feed is a bottoms fraction of a fuels hydrocracker.  
   
   
       3 . The process of Process according to  claim 2 , wherein the content of sulfur in the mixed feed to the pour point reducing treatment is below 50 ppm and the content of nitrogen in the mixed feed to the pour point reducing treatment is below 10 ppm.  
   
   
       4 . The process of  claim 1 , wherein the wax content in the petroleum derived feed is below 30 wt %.  
   
   
       5 . The process of  claim 4 , wherein the pour point of the petroleum derived feed is below −10° C.  
   
   
       6 . The process of  claim 1 , wherein the petroleum derived feed has a saturates content of greater than 98 wt % a viscosity index of between 80 and 150 and a sulfur content of below 0.001 wt %.  
   
   
       7 . The process of  claim 6 , wherein the petroleum derived feed has been obtained in a process comprising a hydrofinishing step performed at a hydrogen pressure of greater than 100 bars.  
   
   
       8 . The process of  claim 1 , wherein the base oil is hydrogenated after performing the pour point reducing treatment such that the content of aromatics is below 1 wt %.  
   
   
       9 . The process of  claim 1 , wherein the catalytic pour point reducing treatment is a catalytic dewaxing process performed in the presence of a catalyst comprising a Group VIII metal and an intermediate pore size zeolite having pore diameter between 0.35 and 0.8 nm, and a binder.  
   
   
       10 . The process of  claim 1 , wherein after performing the catalytic pour point reducing treatment hydrogen is separated from the dewaxed effluent, contacted with a heterogeneous adsorbent selective for removing hydrogen sulfide and recycled to said catalytic pour point reducing treatment.  
   
   
       11 . The process of  claim 10 , wherein the heterogeneous adsorbent is zinc oxide.  
   
   
       12 . The process of  claim 1 , wherein the hydroisomerized Fischer-Tropsch wax is obtained by a process comprising: 
 (a) hydrocracking/hydroisomerizing a Fischer-Tropsch product, and,    (b) distilling the product of step (a) into one or more gas oil fractions and a higher boiling Fischer-Tropsch derived feed.    
   
   
       13 . The process of  claim 12 , wherein the Fischer-Tropsch product used as feed in step (a) is a product wherein the weight ratio of compounds having at least 60 or more carbon atoms and compounds having at least 30 carbon atoms in the Fischer-Tropsch product is at least 0.4 and wherein at least 30 wt % of compounds in the Fischer-Tropsch product have at least 30 carbon atoms.  
   
   
       14 . The process of  claim 2 , wherein the content of sulfur in the mixed feed to the pour point reducing treatment is below 50 ppm and the content of nitrogen in the mixed feed to the pour point reducing treatment is below 10 ppm.  
   
   
       15 . The process of  claim 2 , wherein the wax content in the petroleum derived feed is below 30 wt %.  
   
   
       16 . The process of  claim 15 , wherein the pour point of the petroleum derived feed is below −10° C.  
   
   
       17 . The process of  claim 2 , wherein the petroleum derived feed has a saturates content of greater than 98 wt % a viscosity index of between 80 and 150 and a sulfur content of below 0.001 wt %.  
   
   
       18 . The process of  claim 17 , wherein the petroleum derived feed has been obtained in a process comprising a hydrofinishing step performed at a hydrogen pressure of greater than 100 bars.  
   
   
       19 . The process of  claim 2 , wherein the base oil is hydrogenated after performing the pour point reducing treatment such that the content of aromatics is below 1 wt %.  
   
   
       20 . The process of  claim 2 , wherein the catalytic pour point reducing treatment is a catalytic dewaxing process performed in the presence of a catalyst comprising a Group VIII metal and an intermediate pore size zeolite having pore diameter between 0.35 and 0.8 nm, and a binder.  
   
   
       21 . The process of  claim 2 , wherein after performing the catalytic pour point reducing treatment hydrogen is separated from the dewaxed effluent, contacted with a heterogeneous adsorbent selective for removing hydrogen sulfide and recycled to said catalytic pour point reducing treatment.  
   
   
       22 . The process of  claim 21 , wherein the heterogeneous adsorbent is zinc oxide.  
   
   
       23 . The process of  claim 2 , wherein the hydroisomerized Fischer-Tropsch wax is obtained by a process comprising: 
 (a) hydrocracking/hydroisomerizing a Fischer-Tropsch product, and,    (b) distilling the product of step (a) into one or more gas oil fractions and a higher boiling Fischer-Tropsch derived feed.    
   
   
       24 . The process of  claim 23 , wherein the Fischer-Tropsch product used as feed in step (a) is a product wherein the weight ratio of compounds having at least 60 or more carbon atoms and compounds having at least 30 carbon atoms in the Fischer-Tropsch product is at least 0.4 and wherein at least 30 wt % of compounds in the Fischer-Tropsch product have at least 30 carbon atoms.