Enhanced lube oil yield by low hydrogen pressure catalytic dewaxing of paraffin wax

Abstract

Catalytic dewaxing of paraffin containing feeds, preferably feeds produced from syn gas using a non-shifting Fischer-Tropsch catalyst, is accomplished at relatively low hydrogen partial pressures without substantial effect on the life of the dewaxing catalyst having a certain pore structure.

What is claimed is:  
     
         1 . A catalytic dewaxing process comprising contacting a feed containing 80+ wt % n-paraffin at dewaxing conditions including a hydrogen partial pressure of less than about 500 psig with a catalyst comprising a molecular sieve with a one dimensional pore structure having an average diameter of 0.50 to 0.65 nm and a metal dehydrogenation component, the catalyst having a deactivation rate, measured by temperature increase required (TIR) for meeting a pre-determined pour point or cloud point, of less than 30° F./year.  
     
     
         2 . The process of  claim 1  wherein the hydrogen partial pressure is greater than 0 psig.  
     
     
         3 . The process of  claim 2  wherein the hydrogen partial pressure is less than 400 psig.  
     
     
         4 . The process of  claim 3  wherein TIR is less than 25° F./year.  
     
     
         5 . The process of  claim 4  wherein the paraffin containing feed contains greater than 90 wt % n-paraffins and boils in the range above 430° F.  
     
     
         6 . The process of  claim 5  wherein the feed is derived from a Fischer-Tropsch process and contains less than 50 wppm each of nitrogen and sulfur.  
     
     
         7 . The process of  claim 6  wherein the dehydrogenation component is platinum or palladium.  
     
     
         8 . The process of  claim 7  wherein the hydrogen partial pressure ranges from about 100 to about 350 psig.  
     
     
         9 . The process of  claim 8  wherein reaction temperature ranges from about 550° F. to about 800° F.  
     
     
         10 . The process of  claim 8  wherein total reaction pressure ranges from about 100 to about 2000 psi.  
     
     
         11 . The process of  claim 8  wherein the pour point is −21° C. or lower.  
     
     
         12 . The process of  claim 8  wherein the product of the catalytic dewaxing process is a lube base stock or a diesel range material, and is subjected to a hydrofinishing step.  
     
     
         13 . The process of  claim 12  wherein the product of the catalytic dewaxing process is a lube base stock.  
     
     
         14 . The process of  claim 13  wherein the molecular sieve is selected from the group consisting of ZSM-23, ZSM-35, ZSM-48, ZSM-22, SSZ-32, zeolite beta, mordenite, rare earth ion exchanged ferrierite and mixtures thereof.  
     
     
         15 . The process of  claim 14  wherein the molecular sieve is ZSM-48.  
     
     
         16 . The process of  claim 15  wherein the metal dehydrogenation component comprises a Group VIII metal.  
     
     
         17 . The process of  claim 16  wherein the Group VIII metal is a noble metal.  
     
     
         18 . The process of  claim 16  wherein the metal dehydrogenation component is a noble metal and the molecular sieve is ZSM-48.