Catalyst and hydrotreating process

Abstract

A process for the preparation of a catalyst, which process comprises the steps of: i) mixing an alumina precursor with combustible carbon-containing fibers with a diameter in the range of from 0.5 to 5 μm and a length of no greater than 100 μm in an amount in the range of from 20 to 40 wt % based on the total dry mixture; ii) adding nitric acid and water to form an extrudable mass; iii) extruding the mixture to form shaped particles; iv) drying the shaped particles; v) heating the particles in an atmosphere comprising no more than 5 vol % oxygen at a temperature in the range of from 350 to 600° C.; and vi) then heating the particles in a gas mixture comprising at least 12 vol % oxygen at a temperature in the range of from 450 to 600° C.

1 . A catalyst composition, comprising: alumina, molybdenum or tungsten, and nickel or cobalt, wherein said catalyst composition is prepared by a method that includes mixing an alumina precursor and combustible carbon-containing fibres to form a mixture that is heated to thermally decompose said combustible carbon-containing fibres, and wherein said catalyst composition has a total pore volume of at least 0.40 cm 3 /g; a pore volume of at least 0.15 cm 3 /g in pores having a diameter in the range of from 3 to 10 nm; a macropore volume of at least 0.25 cm 3 /g in pore having a diameter in the range of from 100 to 5000 nm; and a surface area in the range of from 50 to 350 m 2 /g. 
   
   
       2 . A catalyst composition as recited in  claim 1 , wherein said combustible carbon-containing fibres are present in said mixture in an amount in the range of from 20 to 40 wt %, based on the total dry mixture. 
   
   
       3 . A catalyst composition as recited in  claim 2 , wherein said combustible carbon-containing fibres are selected from the group consisting of cotton celluslose, jute, sisal, viscose, nylon, polyethylene, polyamide, polyesters, polyacrylnitrile, polypropylene, polyvinyl alcohol, aramide and carbon fibres. 
   
   
       4 . A catalyst composition as recited in  claim 3 , wherein said combustible carbon-containing fibres have a diameter in the range of from 0.5 to 50 μm and a length no greater than 1000 μm. 
   
   
       5 . A catalyst composition as recited in  claim 4 , wherein said molybdenum or tungsten is present in said catalyst composition in an amount in the range of from 0.1 to 30 wt %, and said nickel or cobalt is present in said catalyst composition in an amount in the range of from 0.1 to 20 wt %, both based on the total dry mixture and calculated as the metal. 
   
   
       6 . A catalyst composition as recited in  claim 5 , wherein said total pore volume is at least 0.55 cm 3 /g; said pore volume in pores having a diameter in the range of from 3 to 10 nm is at least 0.25 cm 3 /g; and said macropore volume in pores having a diameter in the range of from 100 to 5000 nm is in the range of from 0.25 cm 3 /g to 0.35 cm 3 /g. 
   
   
       7 . A process for the demetallization of a hydrocarbon fraction, wherein said process comprises: contacting a hydrocarbon fraction with a catalyst composition, comprising: alumina, molybdenum or tungsten, and nickel or cobalt, wherein said catalyst composition is prepared by a method that includes mixing an alumina precursor and combustible carbon-containing fibres to form a mixture that is heated to thermally decompose said combustible carbon-containing fibres, and wherein said catalyst composition has a total pore volume of at least 0.40 cm 3 /g; a pore volume of at least 0.15 cm 3 /g in pores having a diameter in the range of from 3 to 10 nm; a macropore volume of at least 0.25 cm 3 /g in pore having a diameter in the range of from 100 to 5000 nm; and a surface area in the range of from 50 to 350 m 2 /g. 
   
   
       8 . A process as recited in  claim 7 , wherein said combustible carbon-containing fibres are present in said mixture in an amount in the range of from 20 to 40 wt %, based on the total dry mixture. 
   
   
       9 . A process as recited in  claim 8 , wherein said combustible carbon-containing fibres are selected from the group consisting of cotton celluslose, jute, sisal, viscose, nylon, polyethylene, polyamide, polyesters, polyacrylnitrile, polypropylene, polyvinyl alcohol, aramide and carbon fibres. 
   
   
       10 . A process as recited in  claim 9 , wherein said combustible carbon-containing fibres have a diameter in the range of from 0.5 to 50 μm and a length no greater than 1000 μm. 
   
   
       11 . A process as recited in  claim 10 , wherein said molybdenum or tungsten is present in said catalyst composition in an amount in the range of from 0.1 to 30 wt %, and said nickel or cobalt is present in said catalyst composition in an amount in the range of from 0.1 to 20 wt %, both based on the total dry mixture and calculated as the metal. 
   
   
       12 . A process as recited in  claim 11 , wherein said total pore volume is at least 0.55 cm 3 /g; said pore volume in pores having a diameter in the range of from 3 to 10 nm is at least 0.25 cm 3 /g; and said macropore volume in pores having a diameter in the range of from 100 to 5000 nm is in the range of from 0.25 cm 3 /g to 0.35 cm 3 /g.