Fuel processing system

Abstract

A method and apparatus for processing a hydrocarbon fuel comprises: a primary fuel processing reactor for converting a feed stream to a first reformate stream comprising hydrogen; a first hydrogen separator located downstream of the primary fuel processing reactor and fluidly connected thereto for receiving the first reformate stream, the first separator comprising a first membrane for separating the first reformate stream into a first hydrogen-rich stream and a first retentate stream; and a secondary fuel processing reactor fluidly connected to the first separator for receiving and converting the first retentate stream to a second reformate stream comprising hydrogen. A fuel cell power generation system includes the present apparatus and a fuel cell stack fluidly connected thereto for receiving hydrogen-rich streams therefrom.

What is claimed is:  
     
         1 . A fuel processing system comprising: 
 (a) a primary fuel processing reactor for converting a feed stream to a first reformate stream comprising hydrogen;    (b) a first hydrogen separator located downstream of said primary fuel processing reactor and fluidly connected thereto for receiving said first reformate stream, said first separator comprising a first membrane for separating said first reformate stream into a first hydrogen-rich stream and a first retentate stream; and    (c) a secondary fuel processing reactor fluidly connected to said first separator for receiving and converting said first retentate stream to a second reformate stream comprising hydrogen.    
     
     
         2 . The fuel processing system of  claim 1  wherein said first hydrogen separator is fluidly connected to said secondary fuel processing reactor for receiving said second reformate stream, and said second reformate stream is introduced into said first reformate stream via a compressor.  
     
     
         3 . The fuel processing system of  claim 1  wherein said first hydrogen separator is fluidly connected to said secondary fuel processing reactor for receiving said second reformate stream, and said second reformate stream is introduced into said first reformate stream via an ejector.  
     
     
         4 . The fuel processing system of  claim 1 , further comprising: 
 (d) a second hydrogen separator located downstream of said secondary fuel processing reactor and fluidly connected thereto for receiving said second reformate stream, said second separator comprising a second membrane for separating said second reformate stream into a second hydrogen-rich stream and a second retentate stream.    
     
     
         5 . The fuel processing system of  claim 1  wherein said primary fuel processing reactor is selected from the group consisting of steam reformers, partial oxidation reformers, catalytic partial oxidation reformers, autothermal reformers, and plasma reformers.  
     
     
         6 . The fuel processing system of  claim 5  wherein said secondary fuel processing reactor is selected from the group consisting of steam reformers, partial oxidation reformers, catalytic partial oxidation reformers, autothermal reformers, plasma reformers, and shift reactors.  
     
     
         7 . The fuel processing system of  claim 1  wherein said feed stream comprises synthesis gas or a reformate stream from a high-temperature reformer, and wherein said primary and secondary fuel processing reactors are shift reactors.  
     
     
         8 . The fuel processing system of  claim 1  wherein said primary fuel processing reactor is a steam reformer.  
     
     
         9 . The fuel processing system of  claim 8  wherein said secondary fuel processing reactor is a steam reformer or a shift reactor.  
     
     
         10 . The fuel processing system of  claim 1  wherein said first membrane is selected from the group consisting of palladium membranes, palladium alloy membranes, platinum membranes, platinum alloy membranes, titanium alloy membranes, ceramic membranes, zeolite molecular sieve membranes, carbon molecular sieve membranes, inorganic poly-acid membranes, and composite membranes thereof.  
     
     
         11 . The fuel processing system of  claim 10  wherein said first membrane comprises a palladium membrane or palladium alloy membrane.  
     
     
         12 . The fuel processing system of  claim 11  wherein said first membrane is supported.  
     
     
         13 . The fuel processing system of  claim 1  wherein said first hydrogen separator is independently selected from the group consisting of plate-and-frame, spiral wound, and hollow fiber modules.  
     
     
         14 . The fuel processing system of  claim 4  wherein said first and second membranes are independently selected from the group consisting of palladium membranes, palladium alloy membranes, platinum membranes, platinum alloy membranes, titanium alloy membranes, ceramic membranes, zeolite molecular sieve membranes, carbon molecular sieve membranes, inorganic poly-acid membranes, and composite membranes thereof, and wherein said first and second membranes can be of the same type or different.  
     
     
         15 . The fuel processing system of  claim 14  wherein said first and second membranes comprise palladium membranes or palladium alloy membranes.  
     
     
         16 . The fuel processing system of  claim 15  wherein said first and second membranes are supported.  
     
     
         17 . The fuel processing system of  claim 4  wherein said first and second hydrogen separators are independently selected from the group consisting of plate-and-frame, spiral wound, and hollow fiber modules, and wherein said first and second hydrogen separators can be of the same type or different.  
     
     
         18 . The fuel processing system of  claim 5 , further comprising a fuel supply for supplying said feed stream to said primary reformer.  
     
     
         19 . The fuel processing system of  claim 18  wherein said feed stream comprises a fuel selected from the group consisting of gasoline, diesel, natural gas, ethane, butane, light distillates, dimethyl ether, methanol, ethanol, propane, naphtha, kerosene, and combinations thereof.  
     
     
         20 . The fuel processing system of  claim 19  wherein said fuel is methanol.  
     
     
         21 . The fuel processing system of  claim 1 , further comprising a water supply for supplying water vapor to at least one of said primary and secondary fuel processing reactors.  
     
     
         22 . The fuel processing system of  claim 1 , further comprising a heating device for heating said second reformate stream to a temperature within a predetermined temperature range.  
     
     
         23 . The fuel processing system of  claim 4 , further comprising a heating device for heating said second reformate stream to a temperature within a predetermined temperature range, said heating device being located upstream of said secondary hydrogen separator.  
     
     
         24 . The fuel processing system of  claim 1 , further comprising an oxidant supply for supplying oxidant to at least one of said primary and secondary fuel processing reactors.  
     
     
         25 . A fuel cell power generation system comprising: 
 a fuel processing system according to  claim 1 , and    a fuel cell stack comprising at least one fuel cell fluidly connected to receive said first hydrogen-rich stream from said fuel processing system.    
     
     
         26 . The fuel cell power generation system of  claim 25  wherein said at least one fuel cell is a solid polymer electrolyte fuel cell.  
     
     
         27 . A fuel cell power generation system comprising: 
 a fuel processing system according to  claim 4 , and    a fuel cell stack comprising at least one fuel cell fluidly connected to receive said first and second hydrogen-rich streams from said fuel processing system.    
     
     
         28 . The fuel cell power generation system of  claim 27  wherein said at least one fuel cell is a solid polymer electrolyte fuel cell.