Hydrogen purification apparatus

Abstract

It was difficult to acquire a good CO cleanup efficiency in a hydrogen refining apparatus, for instance, when the start-up and stop operations are frequently repeated. A hydrogen refining apparatus, including a shifter 3 having a shifting catalyst body 3 a containing noble metals and metal oxides, and a reforming section 1 for supplying hydrogen gas containing carbon monoxide to the shifter 3, (1) the temperature of an upstream side of the shifting catalyst body 3 a relative to the hydrogen gas flow being substantially between 300° C. and 500° C. and (2) the temperature of a downstream side of the shifting catalyst body 3 a relative to the hydrogen gas flow being substantially at 300° C. or less.

1 . A hydrogen refining apparatus comprising: 
 a shifter having a shifting catalyst body containing noble metals and metal oxides for converting carbon monoxide; and    a hydrogen gas supplying section for supplying hydrogen gas containing carbon monoxide to said shifter,    wherein (1) the temperature of an upstream side of said shifting catalyst body relative to said hydrogen gas flow is substantially between 300° C. and 500° C. and (2) the temperature of a downstream side of said shifting catalyst body relative to said hydrogen gas flow is substantially at 300° C. or less.    
     
     
         2 . The hydrogen refining apparatus according to  claim 1 , wherein said shifter having a cooling section for keeping the temperature of said downstream side between 150° C. and 300° C.  
     
     
         3 . The hydrogen refining apparatus according to  claim 1 , wherein the amount of said noble metals per volume of said shifting catalyst body is smaller in said upstream side than in said downstream side.  
     
     
         4 . The hydrogen refining apparatus according to  claim 1 , wherein the flow rate of said hydrogen gas is larger in said upstream side than in said downstream side.  
     
     
         5 . The hydrogen refining apparatus according to  claim 1 , wherein 
 the cross-sectional area of said shifting catalyst body perpendicular to said hydrogen gas flow is smaller in said upstream side than in said downstream side.    
     
     
         6 . A hydrogen refining apparatus comprising: 
 a plurality of stages of a shifter having a shifting catalyst body containing both noble metals and metal oxides for converting carbon monoxide; and    a hydrogen gas supplying section for supplying hydrogen gas containing carbon monoxide to said plurality of stages of said shifter,    wherein the temperature of a stage of said shifter having said plurality of stages is higher in a more upstream side relative to said hydrogen gas flow.    
     
     
         7 . The hydrogen refining apparatus according to  claim 1  or  6 , wherein said noble metals are all or a part of Pt, Pd, Rh and Ru, and 
 said metal oxides are composite oxides made by compounding Zr and/or Al with Ce.  
 
     
     
         8 . The hydrogen refining apparatus according to  claim 7 , wherein said composite oxides are, excluding oxygen, composed of 5 to 90 atomic percent of Ce, the balance being Zr and/or Al.  
     
     
         9 . The hydrogen refining apparatus according to  claim 8 , wherein the composite oxides are in the form of a solid solution.  
     
     
         10 . The hydrogen refining apparatus according to  claim 9 , wherein the composition proportion of Ce in a stage of said shifting catalyst body is larger in a more upstream side relative to said hydrogen gas flow.  
     
     
         11 . The hydrogen refining apparatus according to  claim 1  or  6 , wherein (1) between said hydrogen gas supplying section and said shifter, or (2) between said shifting catalyst bodies in respective stages is installed a cooling section used for cooling said hydrogen gas.