Process for treating a gas oil

Abstract

The present invention relates to a process for hydrodesulphurising a gas oil wherein a sulphur level of less than 50 ppm is obtained, said process comprising a) contacting a gas oil with hydrogen in the presence of a hydrodesulphurisation catalyst, and b) adjusting the temperature and pressure of hydrodesulphurisation so the temperature-pressure relationship lies on or between the curves T=211.15 P 0.1363 and T=243.83 P 0.1232 , for all values of P≧0 where T=temperature in ° C., and P=pressure in bar a.

I claim:  
     
         1 . A process for hydrodesulphurising a gas oil wherein a sulphur level of less than 50 ppm is obtained, said process comprising a) contacting a gas oil with hydrogen in the presence of a hydrodesulphurisation catalyst, and b) adjusting the temperature and pressure of hydrodesulphurisation so the temperature-pressure relationship lies on or between the curves T=211.15 P 0.1363  and T=243.83 P 0.1232 , for all values of P>0 where T=temperature in ° C., and P=pressure in bar a.  
     
     
         2 . A process as claimed in  claim 1 , wherein the temperature-pressure relationship lies on or between the curves T=215.79P 0.1363  and T=234.45P 0.1267 .  
     
     
         3 . A process as claimed in  claim 1 , wherein temperature-pressure relationship lies on or between the curves T=215.79 P 0.1342  and T=229.78 P 0.1285 .  
     
     
         4 . A process as claimed in  claim 1 , wherein the gas oil has a T 95 >300° C.  
     
     
         5 . A process as claimed in  claim 4 , wherein the gas oil is selected from the group consisting of light gas oils (LGO), heavy gas oils (HGO), light cycle oils (LCO), coker gas oils (CGO), Visbroken gas oils (VBGO), and mixtures thereof.  
     
     
         6 . A process as claimed in  claim 1 , wherein a sulphur level of less than 30 ppm is obtained.  
     
     
         7 . A process as claimed in  claim 1 , wherein the gas oil is contacted with hydrogen in a ratio of 150:1 to 350:1 (nm 3 /m 3 , measured at 0° C.).  
     
     
         8 . A process as claimed in  claim 1 , wherein the gas oil and hydrogen are pre-heated prior to contacting the catalyst.  
     
     
         9 . A process as claimed in  claim 1 , wherein the catalyst employed in step a) comprises molybdenum and/or tungsten.  
     
     
         10 . A process as claimed in  claim 9 , wherein the catalyst also comprises cobalt and/or nickel.  
     
     
         11 . A process as claimed in  claim 1 , wherein a sulphur level of less than 10 ppm is obtained.