Integrated fuel cell system

Abstract

The invented system includes a fuel-cell system comprising a fuel cell that produces electrical power from air (oxygen) and hydrogen, and a fuel processor that produces hydrogen from a variety of feedstocks. One such fuel processor is a steam reformer which produces purified hydrogen from a carbon-containing feedstock and water. In the invented system, various mechanisms for implementing the cold start-up of the fuel processor are disclosed, as well as mechanisms for optimizing and/or harvesting the heat and water requirements of the system and/or maintaining the purity of the process water used in the system.

1 . A fuel cell system, comprising: 
 a fuel cell stack adapted to receive hydrogen gas and an oxidant and to produce an electric current therefrom, wherein the fuel cell stack includes an anode chamber to which the hydrogen gas is delivered and a cathode chamber to which the oxidant is delivered, and further wherein the fuel cell stack is adapted to produce a water stream that is removed from the fuel cell stack; and    a cooling assembly that is adapted to receive and cool the water stream, wherein the cooling assembly includes an ion-exchange bed through which at least a portion of the water stream is passed to remove ions from the water stream.    
   
   
       2 . The fuel cell system of  claim 1 , wherein only a portion of the water stream is passed through the ion-exchange bed.  
   
   
       3 . The fuel cell system of  claim 1 , wherein all of the water stream is passed through the ion-exchange bed.  
   
   
       4 . The fuel cell system of  claim 1 , wherein the ion-exchange bed includes an anion-exchange resin.  
   
   
       5 . The fuel cell system of  claim 1 , wherein the ion-exchange bed includes a cation-exchange resin.  
   
   
       6 . The fuel cell system of  claim 5 , wherein the ion-exchange bed includes both anion- and cation-exchange resins.  
   
   
       7 . The fuel cell system of  claim 1 , further comprising a water storage reservoir adapted to receive the water stream.  
   
   
       8 . The fuel cell system of  claim 1 , further comprising means for providing hydrogen gas for the fuel cell stack.  
   
   
       9 . The fuel cell system of  claim 1 , further comprising means for producing hydrogen gas for the fuel cell stack.  
   
   
       10 . The fuel cell system of  claim 9 , further comprising means for recovering water from the hydrogen gas.  
   
   
       11 . A method for operating a fuel cell system, the method comprising: 
 producing hydrogen gas;    combusting a fuel stream to produce a heated combustion exhaust stream;    heating at least a portion of a fuel processor and a heat exchange assembly with the heated combustion exhaust stream;    producing hydrogen gas in the fuel processor via a steam reforming reaction;    delivering at least a portion of the hydrogen gas to a fuel cell stack;    heating a fluid with the heat exchange assembly to produce a heated fluid stream; and    delivering at least a portion of the heated fluid stream to at least one of a residential, commercial, or industrial application.    
   
   
       12 . The method of  claim 11 , wherein the fluid is air, and the heated fluid stream is delivered to provide space heating to the application.  
   
   
       13 . The method of  claim 11 , wherein the fluid is water, and the heated fluid stream is delivered to provide space heating to the at least one application.  
   
   
       14 . The method of  claim 11 , wherein the fluid is water, wherein the application is a residential application, and further wherein the heated fluid stream is delivered to provide domestic hot water to the residential application.  
   
   
       15 . The method of  claim 11 , wherein the fluid is water, wherein the application is a commercial application, and further wherein the heated fluid stream is delivered to provide process hot water to the commercial application.  
   
   
       16 . The method of  claim 11 , wherein the fluid is water, wherein the application is an industrial application, and further wherein the heated fluid stream is delivered to provide process hot water to the industrial application.  
   
   
       17 . The method of  claim 11 , wherein the fluid is at least one of ethylene glycol and propylene glycol, and the heated fluid stream is delivered to provide space heating to the at least one application.  
   
   
       18 . The method of  claim 11 , wherein the fuel includes hydrogen gas produced by the fuel processor.  
   
   
       19 . The method of  claim 11 , wherein the fuel includes an exhaust stream from the fuel cell stack.  
   
   
       20 . The method of  claim 11 , wherein the fuel cell stack is adapted to produce a water stream that is removed from the fuel cell stack, and further wherein the method includes removing impurities from the water stream.