Dual use hydrocarbon fuel composition

Abstract

A hydrocarbon fuel composition which is suitable for sue in a fuel cell apparatus and an internal combustion engine comprises at least one saturated aliphatic hydrocarbon having 4 to 12 carbon atoms, and is characterised by . an olefin content of less than 20%, by volume, an aromatics content of less than 42% by volume, a final boiling point (fop) of less than 215° C., and a sulphur content of less than 20 ppm.

1 . A method of fuelling a fuel cell apparatus, said method comprising: 
 providing a fuel composition comprising at least one saturated aliphatic hydrocarbon having 4 to 12 carbon atoms, and characterised by: 
 an olefin content of less than less than 20% by volume,  
 an aromatics content of less than 42% by volume,  
 a final boiling point (fbp) of less than 215° C., and  
 a sulphur content of less than 20 ppm,  
   providing a fuel cell apparatus comprising a conversion unit and a fuel cell unit,    introducing the fuel composition into the conversion unit, and    operating the conversion unit under suitable conditions to convert at least some of the fuel composition into a product stream comprising hydrogen, and optionally,    introducing the hydrogen produced in the conversion unit into the fuel cell unit.    
     
     
         2 . A method of fuelling a fuel cell apparatus and an internal combustion engine, said method comprising: 
 providing a reservoir for a fuel composition comprising at least one saturated aliphatic hydrocarbon having 4 to 12 carbon atoms, and characterised by: 
 an olefin content of less than less than 20% by volume,  
 an aromatics content of less than 42% by volume,  
 a final boiling point (fbp) of less than 215° C., and  
 a sulphur content of less than 20 ppm,  
   providing a first conduit for delivering the fuel composition in said reservoir to a fuel cell apparatus, and a second conduit for delivering the fuel composition in said reservoir to an internal combustion engine, and optionally,    delivering the fuel composition in said reservoir to said fuel cell apparatus via said first conduit, and/or    delivering the fuel composition in said reservoir to said internal combustion engine via said second conduit.    
     
     
         3 . A method as claimed in  claim 1  further comprising passing said fuel composition through a sulphur trap.  
     
     
         4 . A method as claimed in  claim 2  further comprising passing said fuel composition through a sulphur trap.  
     
     
         5 . A method as claimed in  claim 4  in which the sulphur trap is positioned in the first and/or second conduit.  
     
     
         6 . A method as claimed in  claim 4  in which the sulphur trap is located in a third conduit, through which the fuel composition is allowed to pass prior to entering the first and/or second conduits.  
     
     
         7 . A method as claimed in any one of claims  2 ,  4 ,  5  or  6  further comprising adding additives for use in internal combustion engines to the fuel composition in the second conduit, but not to fuel composition in the first conduit.  
     
     
         8 . A method as claimed in  claim 7  further comprising providing means for preventing additive-containing fuel from contaminating the fuel composition in the reservoir or any fuel destined for fuel cell apparatus.  
     
     
         9 . A method as claimed in any one of the preceding claims in which the amount of saturated aliphatic hydrocarbon in said fuel composition is greater than 50% by volume, preferably greater than 70% by volume, more preferably greater than 80% by volume and most preferably greater than 90% by volume.  
     
     
         10 . A method as claimed in any one of the preceding claims in which the fuel composition has an olefin content of less than 10% by volume, preferably, less than 5% by volume and more preferably less than 3% by volume.  
     
     
         11 . A method as claimed in any one of the preceding claims in which the fuel composition has an aromatics content of less than 35% by volume, preferably less than 25% by volume, and more preferably less than 10% by volume.  
     
     
         12 . A method as claimed in any one of the preceding claims in which the fuel composition contains at least one oxygenate, preferably in an amount of less than 5% by volume.  
     
     
         13 . A method as claimed in any one of the preceding claims in which the fuel composition has a sulphur content by weight of less than 10 ppm by weight, more preferably less than 5 ppm, even more preferably less than 1 ppm and most preferably less than 0.5 ppm.  
     
     
         14 . A method as claimed in  claim 13  in which the fuel composition has a sulphur content of less than 0.1 ppm by weight.  
     
     
         15 . A method as claimed in any one of the preceding claims in which the fuel composition has a final boiling point(fbp) of less than 200° C., more preferably less than 185° C. and most preferably less than 180° C.  
     
     
         16 . A method as claimed in  claim 15  in which the fuel composition has a final boiling point in the range 155 to 175° C.  
     
     
         17 . A method as claimed in any one of the preceding claims in which the fuel composition comprises at least 2% by volume triptane or an alkane “A” having 8-12 carbon atoms, preferably, 8 or 10 carbon atoms and having at least 4 methyl and/or ethyl branches.  
     
     
         18 . A method as claimed in  claim 17  in which the fuel composition comprises greater than 70% by volume triptane or an alkane “A” having 8-12 carbon atoms, preferably, 8 or 10 carbon atoms and having at least 4 methyl and/or ethyl branches, preferably, greater than 80% by volume, more preferably, greater than 90% by volume, and most preferably, greater than 95% by volume.  
     
     
         19 . A method as claimed in any one of the preceding claims in which the fuel composition further comprises additives for use in an internal combustion engine.  
     
     
         20 . A hydrocarbon fuel composition which is suitable for use in a fuel cell apparatus and an internal combustion engine, said hydrocarbon fuel composition comprising at least one saturated aliphatic hydrocarbon having 4 to 12 carbon atoms, and characterised by: 
 an olefin content of less than less than 20% by volume,    an aromatics content of less than 42% by volume,    a final boiling point (fbp) of less than 185° C., and    a sulphur content of less than 20 ppm.    
     
     
         21 . A fuel composition as claimed in  claim 20  in which the amount of saturated aliphatic hydrocarbon in said fuel composition is greater than 50% by volume, preferably greater than 70% by volume, more preferably greater than 80% by volume and most preferably greater than 90% by volume.  
     
     
         22 . A fuel composition as claimed in  claim 20  or  claim 21  which has an olefin content of less than 10% by volume, preferably, less than 5% by volume and more preferably less than 1% by volume.  
     
     
         23 . A fuel composition as claimed in any one of  claims 20  to  22  which has an aromatics content of less than 35% by volume, preferably less than 25% by volume, and more preferably less than 10% by volume.  
     
     
         24 . A fuel composition as claimed in any one of  claims 20  to  23  which contains at least one oxygenate, preferably in an amount of less than 5% by volume.  
     
     
         25 . A fuel composition as claimed in any one of  claims 20  to  24  having a sulphur content by weight of less than 10 ppm by weight, more preferably less than 5 ppm, even more preferably less than 1 ppm and most preferably less than 0.5 ppm.  
     
     
         26 . A fuel composition as claimed in  claim 25  having a sulphur content of less than 0.1 ppm by weight.  
     
     
         27 . A fuel composition as claimed in any one of  claims 20  to  26  having a final boiling point(fbp) of less than 180° C.  
     
     
         28 . A fuel composition as claimed in  claim 27  having a final boiling point in the range 155 to 175° C.  
     
     
         29 . A fuel composition as claimed in any one of  claims 20  to  28  comprising at least 2% by volume triptane or an alkane “A” having 8-12 carbon atoms, preferably, 8 or 10 carbon atoms and having at least 4 methyl and/or ethyl branches.  
     
     
         30 . A fuel composition as claimed in  claim 29  comprising greater than 70% by volume triptane or an alkane “A” having 8-12 carbon atoms, preferably, 8 or 10 carbon atoms and having at least 4 methyl and/or ethyl branches, preferably, greater than 80% by volume, more preferably, greater than 90% by volume, and most preferably, greater than 95% by volume.  
     
     
         31 . A fuel composition as claimed in any one of  claims 20  to  30  further comprising additives for use in an internal combustion engine.  
     
     
         32 . The use of a fuel composition as claimed in any one of  claims 20  to  31  as a fuel for a fuel cell powered vehicle.  
     
     
         33 . A method of fuelling a fuel cell apparatus, said method comprising: 
 providing a fuel composition as claimed in any one of  claims 20  to  31 ,    providing a fuel cell apparatus comprising a conversion unit and a fuel cell unit,    introducing the fuel composition into the conversion unit, and operating the conversion unit under suitable conditions to convert at least some of the fuel composition into a product stream comprising hydrogen, and optionally,    introducing the hydrogen produced in the conversion unit into the fuel cell unit.    
     
     
         34 . A method of fuelling a fuel cell apparatus and an internal combustion engine, said method comprising: 
 providing a reservoir for a fuel composition as claimed in any one of  claims 20  to  31 ,    providing a first conduit for delivering the fuel composition in said reservoir to a fuel-cell apparatus, and a second conduit for delivering the fuel composition in said reservoir to an internal combustion engine, and optionally,    delivering the fuel composition in said reservoir to said fuel cell apparatus via said first conduit, and/or    delivering the fuel composition in said reservoir to said internal combustion engine via said second conduit.    
     
     
         35 . A method as claimed in  claim 33  further comprising passing said fuel composition through a sulphur trap.  
     
     
         36 . A method as claimed in  claim 34  further comprising passing said fuel composition through a sulphur trap.  
     
     
         37 . A method as claimed in  claim 36  in which the sulphur trap is positioned in the first and/or second conduit.  
     
     
         38 . A method as claimed in  claim 36  in which the sulphur trap is located in a third conduit, through which the fuel composition is allowed to pass prior to entering the first and/or second conduits.  
     
     
         39 . A method as claimed in any one of claims  34 ,  36 ,  37  or  38  further comprising adding additives for use in internal combustion engines to the fuel composition in the second conduit, but not to fuel composition in the first conduit.  
     
     
         40 . A method as claimed in  claim 39  further comprising providing means for preventing additive-containing fuel from contaminating the fuel composition in the reservoir or any fuel destined for fuel cell apparatus.  
     
     
         41 . A method for preparing a fuel composition as claimed in any one of  claims 20  to  31  or for use in a method or use as claimed in any one of  claims 1  to  19 , or  32  to  40  which method comprises blending iso-paraffin (alkylate), hydrocrackate and isomerate together.  
     
     
         42 . A method as claimed in  claim 41  in which the amount of iso-paraffin employed is such that it forms 20 to 80% by volume, preferably, 50 to 70% by volume, for example, 60% by volume of the final fuel composition.  
     
     
         43 . A method as claimed in  claim 41  or  claim 42  in which the amount of hydrocrackate employed is such that it forms 5 to 35% by volume, preferably, 10 to 30% by volume, for example, 20% by volume of the final fuel composition.  
     
     
         44 . A method as claimed in any one of  claims 41  to  43  in which the amount of isomerate employed is such that it forms 10 to 50% by volume, preferably, 20 to 40% by volume, for example, 30% by volume of the final fuel composition.  
     
     
         45 . A method as claimed in any one of  claims 41  to  44  in which there is included in the fuel composition reformate and/or Full Range Catalytically Cracked Spirit (FRCCS).  
     
     
         46 . A method as claimed in  claim 45  in which the reformate is included in the fuel composition in an amount of greater than 0 to 40, for example, 20% by volume of the fuel composition.  
     
     
         47 . A method as claimed in  claim 45  or  claim 46  in which the amount of FRCCS is included in the fuel composition in an amount of greater than 0 to 30, for example, 15% by volume.