Method for desulfurization of hydrocarbon oil

Abstract

Disclosed is a method for desulfurization of a hydrocarbon oil (e.g., kerosene which is a raw fuel for a fuel cell) which can effectively remove benzothiophenes and dibenzothiophenes contained in the hydrocarbon oil under mild conditions to produce a desulfurized hydrocarbon oil having a significantly low sulfur content. The method comprises the step of desulfurizing the hydrocarbon oil such as kerosene containing benzothiophenes and dibenzothiophenes with the combination of a solid acid-type desulfurizing agent and an active carbon-type desulfurizing agent. This method can provide a hydrocarbon oil having a significantly low sulfur content. By using the hydrocarbon oil, the operation or maintenance of a fuel cell system can be made easily, a fuel cell itself can be miniaturized in size, and the lifetime of a desulfurizing agent in a desulfurization apparatus equipped in a fuel cell system can be prolonged.

1 . A method for desulfurization of hydrocarbon oil comprising desulfurization of hydrocarbon oil containing benzothiophenes and dibenzothiophenes using a solid acid desulfurization agent and an activated carbon desulfurization agent in combination. 
   
   
       2 . The method for desulfurization of hydrocarbon oil according to  claim 1  comprising removing all or a part of the dibenzothiophenes in hydrocarbon oil using an activated carbon desulfurization agent and then removing all or a part of the benzothiophenes using a solid acid desulfurization agent. 
   
   
       3 . The method for desulfurization of hydrocarbon oil according to  claim 1  comprising removing all or a part of the benzothiophenes and the dibenzothiophenes in hydrocarbon oil using a solid acid desulfurization agent and then removing all or a part of the remaining dibenzothiophenes using an activated carbon desulfurization agent. 
   
   
       4 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein the hydrocarbon oil is kerosene. 
   
   
       5 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein sulfur removal by the activated carbon desulfurization agent is carried out at a temperature of 100° C. or below. 
   
   
       6 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein sulfur removal by the solid acid desulfurization agent is carried out at a temperature of 5 to 150° C. 
   
   
       7 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein the solid acid desulfurization agent is a solid superacid selected from a group consisting of sulfated zirconia, sulfated alumina, sulfated tin oxide, sulfated iron oxide, tungstated zirconia, and tungstated tin oxide. 
   
   
       8 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein the activated carbon desulfurization agent comprises a carbon material having a specific surface area of 500 m 2 /g of more, and a micropore specific surface area (Smicro [m 2 /g]), a micropore external pore volume (Vext [cm 3 /g]) and a micropore external specific surface area (Sext [m 2 /g]) satisfying the following formula (1),
   Smicro×2×Vext/Sext>3.0  (1).   
   
   
       9 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein the kerosene is desulfurized using the solid acid desulfurization agent and the activated carbon desulfurization agent, after that further treated with a metallic desulfurization agent to remove a very small amount of sulfur compounds remained. 
   
   
       10 . The method for desulfurization of hydrocarbon oil according to  claim 9 , wherein the removal of the very small amount of sulfur compounds by the metallic desulfurization agent is carried out at a temperature of 10 to 300° C. 
   
   
       11 . The method for desulfurization of hydrocarbon oil according to  claim 9 , wherein the metallic desulfurization agent is a copper oxide-based desulfurization agent and/or a nickel-containing desulfurization agent. 
   
   
       12 . The method for desulfurization of hydrocarbon oil according to  claim 2  comprising removing all or a part of the dibenzothiophenes using an activated carbon desulfurization agent and then removing all or a part of the benzothiophenes using a solid acid desulfurization agent in at least one location selected from a fuel cell system, a movable tank storage, a service station, an oil terminal, and a refinery. 
   
   
       13 . The method for desulfurization of hydrocarbon oil according to  claim 2  comprising removing all or a part of the dibenzothiophenes using an activated carbon desulfurization agent in at least one location selected from a movable tank storage, a service station, an oil terminal, and a refinery, then removing all or a part of the benzothiophenes using a solid acid desulfurization agent in a fuel cell system. 
   
   
       14 . The method for desulfurization of hydrocarbon oil according to  claim 3  comprising removing all or a part of the benzothiophenes and the dibenzothiophenes in the hydrocarbon oil using a solid acid desulfurization agent and then removing all or a part of the remaining dibenzothiophenes using a activated carbon desulfurization agent in at least one location selected from a fuel cell system, a movable tank storage, a service station, an oil terminal, and a refinery. 
   
   
       15 . The method for desulfurization of hydrocarbon oil according to  claim 1 , wherein the sulfur content in the kerosene is 20 ppb or less after desulfurization. 
   
   
       16 . The method for desulfurization of hydrocarbon oil according to  claim 2 , wherein the hydrocarbon oil is kerosene. 
   
   
       17 . The method for desulfurization of hydrocarbon oil according to  claim 2 , wherein sulfur removal by the activated carbon desulfurization agent is carried out at a temperature of 100° C. or below. 
   
   
       18 . The method for desulfurization of hydrocarbon oil according to  claim 2 , wherein sulfur removal by the solid acid desulfurization agent is carried out at a temperature of 5 to 150° C. 
   
   
       19 . The method for desulfurization of hydrocarbon oil according to  claim 2 , wherein the activated carbon desulfurization agent comprises a carbon material having a specific surface area of 500 m 2 /g of more, and a micropore specific surface area (Smicro [m 2 /g]), a micropore external pore volume (Vext [cm 3 /g]) and a micropore external specific surface area (Sext [m 2 /g]) satisfying the following formula (1),
   Smicro×2×Vext/Sext>3.0  (1).   
   
   
       20 . The method for desulfurization of hydrocarbon oil according to  claim 10 , wherein the metallic desulfurization agent is a copper oxide-based desulfurization agent and/or a nickel-containing desulfurization agent.