Fuel oil for fuel cell, fuel oil composition, and automobile driving system

Abstract

A fuel oil for a fuel cell which contains, as a predominant component, a desulfurized light naphtha having a ratio of iso-paraffins to normal paraffins of 1 or more by weight; a fuel oil for a fuel cell, characterized by containing a deeply desulfurized light naphtha and can be used for both a hybrid engine and a fuel cell; and an automobile driving system using the composition. The above fuel oil and fuel oil composition can produce hydrogen with good efficiency, does not affect adversely a reformation catalyst or an electrode of a fuel cell, reduces deterioration of a reformation catalyst or the like, and thus can be used as a fuel oil for a fuel cell suitable for a transportation vehicle such as an automobile. The fuel oil composition can be used also as a fuel oil for a hybrid engine.

1 . A fuel oil for use in a fuel cell comprising, as a predominant component, desulfurized light naphtha having a ratio by weight of iso-paraffin to normal paraffin of at least 1.  
     
     
         2 . A fuel oil for use in a fuel cell according to  claim 1 , wherein the ratio by weight of iso-paraffin to normal paraffin contained in the desulfurized light naphtha is at least 1.5.  
     
     
         3 . A fuel oil for use in a fuel cell according to  claim 1 , which has a vapor pressure of 0.098 MPa or lower.  
     
     
         4 . A fuel oil for use in a fuel cell according to  claim 1 , which comprises isomerized desulfurized light naphtha which is obtained through isomerization of raw material desulfurized light naphtha, to thereby increase the ratio by weight of iso-paraffin to normal paraffin as compared with the raw material desulfurized light naphtha; or through isomerization of raw material light naphtha, to thereby increase the ratio by weight of iso-paraffin to normal paraffin as compared with the raw material light naphtha, followed by desulfurization.  
     
     
         5 . A fuel cell which employs a fuel oil as recited in any one of  claims 1  to  4 .  
     
     
         6 . A fuel oil for use in a fuel cell characterized by comprising deeply desulfurized light naphtha.  
     
     
         7 . A fuel oil for use in a fuel cell according to  claim 6 , wherein the deeply desulfurized light naphtha contains sulfur in an amount of 0.5 ppm by weight or less.  
     
     
         8 . A fuel oil for use in a fuel cell according to  claim 6 , wherein the deeply desulfurized light naphtha contains sulfur in an amount of 0.1 ppm by weight or less.  
     
     
         9 . A fuel oil for use in a fuel cell according to  claim 6 , wherein the deeply desulfurized light naphtha contains sulfur in an amount of 0.05 ppm by weight or less.  
     
     
         10 . A fuel oil for use in a fuel cell according to  claim 6 , which contains deeply desulfurized light naphtha in an amount of at least 10% by volume and contains sulfur in an amount of 1 ppm by weight or less.  
     
     
         11 . A fuel oil for use in a fuel cell according to  claim 10 , which contains deeply desulfurized light naphtha in an amount of at least 50% by volume.  
     
     
         12 . A fuel oil for use in a fuel cell according to  claim 6 , which contains deeply desulfurized light naphtha in an amount of at least 50% by volume and contains sulfur in an amount of 0.1 ppm by weight or less.  
     
     
         13 . A fuel cell which employes a fuel oil as recited in any one of  claims 6  to  12 .  
     
     
         14 . A method for producing hydrogen from a fuel oil for use in a fuel cell as recited in any one of  claims 6  to  12 , characterized by performing no desulfurization.  
     
     
         15 . A reforming unit for producing hydrogen characterized by employing a fuel oil for use in a fuel cell as recited in any one of  claims 6  to  12  and comprising no desulfirizer.  
     
     
         16 . A fuel oil composition which contains deeply desulfurized light naphtha and is employable in both a hybrid engine and a fuel cell.  
     
     
         17 . A fuel oil composition according to  claim 16 , which contains sulfur in a concentration of 1 ppm by weight or less.  
     
     
         18 . A fuel oil composition according to  claim 16 , which contains sulfur in a concentration of 0.5 ppm by weight or less.  
     
     
         19 . A fuel oil composition according to  claim 16 , which further contains a detergent-dispersant.  
     
     
         20 . A fuel oil composition according to  claim 19 , which contains the detergent-dispersant in an amount of 10-1,000 ppm by weight.  
     
     
         21 . A fuel oil composition according to  claim 16 , which comprises a supplementary material containing deeply desulfurized light naphtha in an amount of at least 10% by volume.  
     
     
         22 . A fuel oil composition according to  claim 19 , which contains a supplementary material constituted solely by deeply desulfurized light naphtha.  
     
     
         23 . An automobile driving system for driving an automobile mounting a hybrid engine, wherein the automobile employs, as a fuel, a fuel oil composition as recited in any one of  claims 16  to  22 , and the system is configured such that driving within a high load region is basically performed by a motor and driving within a low load region is basically performed by an internal combustion engine.  
     
     
         24 . An automobile driving system according to  claim 23 , wherein the system is configured such that driving is performed by the motor and the internal combustion engine is employed mainly for charging the motor.  
     
     
         25 . An automobile driving system according to  claim 23 , wherein the internal combustion engine is a direct injection gasoline engine.