Catalyst to attain low sulfur gasoline

Abstract

This invention relates to a hydrodesulfurization catalyst, a method for preparing the catalyst, and a method for the preparation of low sulfur gasoline fuel with minimal loss of RON. The catalyst particles include a group VIB metal and a support material having relatively high surface area, and optionally includes one or more group VIIIB metal. The method for preparing the catalyst allows for greater loading of the active metal species on the surface of the support material under aqueous reaction conditions.

We claim: 
     
         1 . A catalyst, composition comprising:
 an activated carbon catalyst support material;   a first metal selected from the group consisting of chromium, molybdenum and tungsten, wherein the first metal is present in the oxide form of the metal in an amount of between about 15 and 30% by weight of the support material; and   a second metal selected from the group consisting of iron, ruthenium, osmium, cobalt, rhenium, iridium, nickel, palladium and platinum, wherein the second metal is present In the oxide form of the metal in an amount of between about 1 and 10% by weight of the support material.   
     
     
         2 . The catalyst composition of  claim 1  further comprising boron. 
     
     
         3 . The catalyst composition of  claim 1  further comprising phosphorous. 
     
     
         4 . The catalyst composition of  claim 1  prepared by the process comprising:
 preparing a first mixture comprising a molybdenum salt, an activated carbon support and water, wherein the first mixture is under vacuum; 
 removing the water from the first mixture to produce a solid catalyst precursor; 
 preparing a second mixture comprising a metal salt selected from a nickel or cobalt salt, water and the solid catalyst precursor; 
 removing the water from the second mixture to produce catalyst particles; 
 calcinating the catalyst particles by heating the particles to a temperature of greater than about 200° C.; and 
 partially sulfiding the calcinated catalyst particles by contacting the calcinated catalyst particles with a gas stream comprising up to about 10% by volume hydrogen sulfide. 
 
     
     
         5 . A method for hydrodesulfurizing a petroleum based hydrocarbon distillate comprising:
 contacting the petroleum hydrocarbon distillate with hydrogen gas in the presence of a hydrodesulfurization catalyst;   wherein the hydrodesulfurization catalyst comprises an activated carbon catalyst support material, a first metal selected from the group consisting of chromium, molybdenum and tungsten, and a second metal selected from the group consisting of iron, ruthenium, osmium, cobalt, rhenium, iridium, nickel, palladium and platinum;   wherein the hydrodesulfurization catalyst comprises between about 10 and 30% by weight of the oxide form of the first metal and between about 1 and 10% by weight of the oxide form of the second metal.   
     
     
         6 . The method of  claim 5  wherein the hydrodesulfurization catalyst is prepared by the process comprising:
 preparing a mixture comprising at least one metal salt, a catalyst support and water, wherein the mixture is under vacuum; 
 removing the water from, the mixture and collecting the catalyst particles; 
 calcinating the particles by heating the particles to a temperature of greater man about 200° C.; and 
 partially sulfiding the catalyst particles by contacting the calcined catalyst particles with a gas stream comprising up to about 5% by volume hydrogen sulfide; 
 wherein the metal salt comprises a first metal selected from the group consisting of chromium, molybdenum, and tungsten. 
 
     
     
         7 . The method of  claim 5  wherein the hydrodesulfurization catalyst comprises at least about 20% by weight molybdenum and at least about 2% by weight nickel. 
     
     
         8 . The method of  claim 5  wherein the hydrodesulfurization catalyst comprises at least about 20% by weight molybdenum and at least about 2% by weight cobalt.