Use Of A Catalyst Comprising A Beta Silicon Carbide Support In A Selective Hydrodesulphurization Process

Abstract

The invention concerns the use of supported catalysts comprising at least one metal or metallic compound of a metal from group VI and/or group VIII deposited on a support essentially constituted by β silicon carbide in a process for selective hydrodesulphurization of an olefinic hydrocarbon feed that is substantially free of polynuclear aromatics and metals. The invention can be used to carry out deep desulphurization of catalytically cracked gasoline cuts with very limited saturation of olefins and thus a minimum loss of octane number.

1 - 6 . (canceled) 
     
     
         7 . In a process comprising subjecting an olefinic hydrocarbon feed to selective catalytic hydrodesulphurization at 200-400° C.° wherein the olefinic hydrocarbon feed that is essentially free of polynuclear aromatics and metals, the improvement wherein the catalyst is a supported catalyst comprising at least one metal or metallic compound of a metal from the group formed by elements from group VIII and/or group VIB of the periodic table deposited on a support consisting essentially of β silicon carbide so as to lower the degree of hydrogenation of the olefins in the feed as compared to the use of a support of alumina having essentially the same surface area and catalytic components, thereby limiting initial hydrogenation over activity and minimizing startup time. 
     
     
         8 . A process according to  claim 7 , wherein the feed has an end point of less than 260° C., and comprises at least 5% by weight of olefins. 
     
     
         9 . A process according to  claim 7 , wherein the feed boils in the gasoline range. 
     
     
         10 . In a process according to  claim 9 , wherein the feed comprises at least 50% by weight of pyrolysis gasoline and/or fluid catalytic cracking gasoline. 
     
     
         11 . A process according to  claim 7 , in which the support has a specific surface area in the range of 5 to 300 m 2 /g. 
     
     
         12 . A process according to  claim 7 , carried out at a pressure in the range of 0.5 to 4 MPa, with a H feed ratio in the range 100 to 600 (litre/litre) and with an hourly mass flow rate of feed with respect to catalyst (WHSV) in the range of 1 to 15 h −1 . 
     
     
         13 . A process according to  claim 11 , said catalyst having a specific surface in the range of 10 to 250 m 2 /g. 
     
     
         14 . A process according to  claim 7 , said catalyst having a pore volume of 0.20 cm 3 /g to 1.0 cm 3 /g. 
     
     
         15 . A process according to  claim 7 , said catalyst having a pore volume of 0.3 cm 3 /g to 0.8 cm 3 /g. 
     
     
         16 . A process according to  claim 7 , said catalyst having a pore volume of 0.35 cm 3 /g to 0.65 cm 3 /g. 
     
     
         17 . A process according to  claim 7 , wherein the amount of metals in mols per gram of support is 6.94×10 −5  to 1.40×10 −3  mols of the group VIB metal, and 4.0×10 −5  to 1.1×10 −3  mols of the group VIII metal. 
     
     
         18 . A process according to  claim 7 , wherein the group VIB metal is molybdenum and the group VIII metal is cobalt. 
     
     
         19 . A process according to  claim 7 , wherein the metals are sulfurized. 
     
     
         20 . A process according to  claim 18 , wherein the metals are sulfurized. 
     
     
         21 . In a process comprising subjecting an olefinic hydrocarbon feed to selective catalytic hydrodesulphurization at 200-400° C.° wherein the olefinic hydrocarbon feed is free of polynuclear aromatics and metals, the improvement wherein the catalyst is a supported catalyst comprising at least one metal or metallic compound of a metal from the group formed by elements from group VIII and/or group VIB of the elements periodic table deposited on a support consisting of β silicon carbide so as to lower the degree of hydrogenation of the olefins in the feed as compared to the use of a support of alumina having essentially the same surface area and catalytic components, thereby limiting initial hydrogenation over activity and minimizing startup time. 
     
     
         22 . A process according to  claim 17 , wherein the group VIB metal is molybdenum and the group VIII metal is cobalt. 
     
     
         23 . A process according to  claim 22 , said catalyst having a pore volume of 0.35 cm 3 /g to 0.65 cm 3 /g. 
     
     
         24 . A process according to  claim 23 , wherein the group VIB metal is molybdenum and the group VIII metal is cobalt. 
     
     
         25 . A process according to  claim 24 , said catalyst having a specific surface in the range of 10 to 250 m 2 /g.