Reforming apparatus for making a co-reduced reformed gas

Abstract

This reforming apparatus is provided with a raw material reforming unit including a heat source for generating heat when a fuel gas is burnt and adapted to reaction heat directly from the heat source, steam-reform a material, and produce a reformed gas containing hydrogen as a main component, a shift reaction unit for reducing by a water shift reaction the amount of CO contained in the reformed gas produced in the raw material reforming unit, a CO oxidation unit adapted to further reduce the amount of CO contained in the reformed gas after the process in the shift reaction unit, by oxidizing the same. These units are united as independent units. These raw material reforming unit, shift reaction unit and CO oxidation unit are arranged so that the shift reaction unit and the CO oxidation unit are indirectly heated by the heat transmitted from the heat source of the raw material reforming unit. The indirect heating is conducted by a method of heat transmission in solid by which heat is transmitted from the outer faces of the combustion chamber via an intermediate member, a method utilizing radiant heat, and a method utilizing heat of a combustion exhaust gas discharged from the combustion chamber. Since this reforming apparatus is provided with these three independent reaction sections united together, it can be miniaturized, and the heat from the heat source can be utilized effectively, and the controlling of temperature in the reaction sections can be done excellently.

1. A reforming apparatus comprising an integrated structure of three separate units, comprising:
 a raw material reforming unit for steam-reforming a raw material to be reformed and producing a reformed gas containing hydrogen as a principal component, including a heat source that generates heat by combustion of a fuel gas, operable to directly obtain heat for the steam reformation reaction from said heat source;  
 a shift reaction unit for decreasing, by water-gas-shift reaction, CO contained in the reformed gas produced in said raw material reforming unit; and  
 a CO oxidation unit for further decreasing, by oxidation, CO contained in reformed gas treated in said shift reaction unit;  
 said raw material reforming unit and said shift reaction unit contain different catalysts, and said shift reaction unit and said CO oxidation unit being arranged in a manner that said shift reaction unit and said CO oxidation unit can be indirectly heated by heat transfer from the heat source of said raw material reforming unit, and further said CO oxidation unit including an outside surface, and being arranged to obtain atmospheric cooling of the outside surface; and  
 said raw material reforming unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to each other with said CO oxidation unit placed on an outer peripheral side of the reforming apparatus.  
 
     
     
       2. The reforming apparatus according to  claim 1 , wherein said raw material reforming unit comprises a generally cylindrical combustion chamber as the heat source and a reforming reaction unit for steam-reforming the raw material to produce the reformed gas containing hydrogen as a principal component, said reforming reaction unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to said combustion chamber. 
     
     
       3. The reforming apparatus according to  claim 2 , wherein said reforming reaction unit is concentrically accommodated within said combustion chamber. 
     
     
       4. The reforming apparatus according to  claim 2 , wherein said reforming reaction unit is positioned outside said combustion chamber in contact therewith. 
     
     
       5. The reforming apparatus according to  claim 2 , said combustion chamber comprising a center, and further comprising an incombustible core arranged at the center of said combustion chamber. 
     
     
       6. The reforming apparatus according to  claim 2 , wherein both of said shift reaction unit and said CO oxidation unit are positioned outside said reforming reaction unit. 
     
     
       7. The reforming apparatus according to  claim 6 , further comprising a partition wall having a function of regulating heat transfer, the partition wall being interposed between said reforming reaction unit and both of said shift reaction unit and said CO oxidation unit. 
     
     
       8. The reforming apparatus according to  claim 6 , wherein said reforming reaction unit and said shift reaction unit are connected by a flow path detouring outside both of said shift reaction unit and said CO oxidation unit. 
     
     
       9. The reforming apparatus according to  claim 6 , wherein said shift reaction unit is arranged on a side adjacent to a high temperature zone of said reforming unit and said CO oxidation unit is arranged on a side adjacent a low temperature said  side of said reforming reaction unit, so as to be in conformity to a temperature distribution within said reforming reaction unit. 
     
     
       10. The reforming apparatus according to  claim 1 , wherein each of said shift reaction unit and said CO oxidation unit is arranged in a position which is heated by a burned exhaust gas from said heat source of said raw material reforming unit. 
     
     
       11. A reforming apparatus comprising an integrated structure of three separate units, comprising:
 a raw material reforming unit for steam-reforming a raw material to be reformed and producing a reformed gas containing hydrogen as a principal component, including a heat source that generates heat by combustion of a fuel gas, operable to directly obtain heat for the steam reformation reaction from said heat source;  
 a shift reaction unit for decreasing, by water-gas-shift reaction, CO contained in the reformed gas produced in said raw material reforming unit; and  
 a CO oxidation unit for further decreasing, by oxidation, CO contained in reformed gas treated in said shift reaction unit;  
 said raw material reforming unit and said shift reaction unit contain different catalysts, and said shift reaction unit and said CO oxidation unit being arranged in a manner that said shift reaction unit and said CO oxidation unit can be indirectly heated by heat transfer from the heat source of said raw material reforming unit, and further said CO oxidation unit being arranged in a position outside said raw material reforming unit;  
 said raw material reforming unit comprising a generally cylindrical combustion chamber as the heat source and a reforming reaction unit for steam-reforming the raw material to produce the reformed gas containing hydrogen as a principal component, said reforming reaction unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to said combustion chamber; and  
 further comprising an exhaust chamber, in which a burned exhaust gas from said combustion chamber directly flows, wherein said exhaust chamber is positioned adjacent to and coaxially above said combustion chamber, said shift reaction unit being positioned outside said exhaust chamber, said CO oxidation unit being positioned outside said shift reaction unit.  
 
     
     
       12. The reforming apparatus according to  claim 11 , further comprising an air intake for introducing fresh air in between said combustion chamber and said exhaust chamber. 
     
     
       13. The reforming apparatus according to  claim 11 , further comprising a secondary heating element for heating said exhaust chamber. 
     
     
       14. The reforming apparatus according to  claim 11 , further comprising an exhaust vent for discharging the burned exhaust gas in said exhaust chamber to the outside, a shutter for selectively opening and closing said exhaust vent, a first duct which is separated from said exhaust chamber and interposed between said shift reaction unit and said CO oxidation unit, and a second duct which is fluid-connected with said first duct and positioned outside said CO oxidation unit. 
     
     
       15. The reforming apparatus according to  claim 14 , further comprising an air intake for introducing fresh air into said first duct. 
     
     
       16. The reforming apparatus according to claim  12    11 , further comprising an incombustible core arranged at the center of said exhaust chamber. 
     
     
       17. A reforming apparatus comprising an integrated structure of three separate units, comprising:
 a raw material reforming unit for steam-reforming a raw material to be reformed and producing a reformed gas containing hydrogen as a principal component, including a heat source that generates heat by combustion of a fuel gas, operable to directly obtain heat for the steam reformation reaction from said heat source;  
 a shift reaction unit for decreasing, by water-gas-shift reaction, CO contained in the reformed gas produced in said raw material reforming unit; and  
 a CO oxidation unit for further decreasing, by oxidation, CO contained in reformed gas treated in said shift reaction unit;  
 said raw material reforming unit and said shift reaction unit contain different catalysts, and said shift reaction unit and said CO oxidation unit being arranged in a manner that said shift reaction unit and said CO oxidation unit can be indirectly heated by heat transfer from the heat source of said raw material reforming unit, and further said CO oxidation unit being arranged in a position outside said raw material reforming unit;  
 said raw material reforming unit comprising a generally cylindrical combustion chamber as the heat source and a reforming reaction unit for steam-reforming the raw material to produce the reformed gas containing hydrogen as a principal component, said reforming reaction unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to said combustion chamber; and  
 at least one of said reforming reaction unit, said shift reaction unit and said CO oxidation unit is provided on a surface thereof with a heat transfer material having a higher heat conductivity than that of a material of which said surface is composed.  
 
     
     
       18. The reforming apparatus according to  claim 2 , wherein said CO oxidation unit includes fins for heat dissipation on an outer surface thereof. 
     
     
       19. A reforming apparatus comprising an integrated structure of three separate units, comprising:
 a raw material reforming unit for steam-reforming a raw material to be reformed and producing a reformed gas containing hydrogen as a principal component, including a heat source that generates heat by combustion of a fuel gas, operable to directly obtain heat for the steam reformation reaction from said heat source;  
 a shift reaction unit for decreasing, by water-gas-shift reaction, CO contained in the reformed gas produced in said raw material reforming unit; and  
 a CO oxidation unit for further decreasing, by oxidation, CO contained in reformed gas treated in said shift reaction unit;  
 said raw material reforming unit and said shift reaction unit contain different catalysts, and said shift reaction unit and said CO oxidation unit being arranged in a manner that said shift reaction unit and said CO oxidation unit can be indirectly heated by heat transfer from the heat source of said raw material reforming unit, and further said CO oxidation unit being arranged in a position outside said raw material unit;  
 said raw material reforming unit comprising a generally cylindrical combustion chamber as the heat source and a reforming reaction unit for steam-reforming the raw material to produce the reformed gas containing hydrogen as a principal component, said reforming reaction unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to said combustion chamber; and  
 further comprising a main exhaust chamber in which a burned exhaust gas from said combustion chamber directly flows, a main exhaust vent for directly discharging the burned exhaust gas in said main exhaust chamber to the outside, a shutter for selectively opening and closing said main exhaust vent, a first duct which is separated from said main exhaust chamber and fluid-connected thereto and is positioned outside said main exhaust chamber, and a second duct which is fluid-connected with said first duct and positioned outside said first duct, said shift reaction unit being placed in said first duct, said CO oxidation unit being placed in said second duct.  
 
     
     
       20. The reforming apparatus according to  claim 19 , further comprising an exhaust sub-vent for discharging a burned exhaust gas within said first duct to the outside, and a shutter for selectively opening and closing said exhaust sub-vent. 
     
     
       21. The reforming apparatus according to  claim 19 , wherein at least one of said reforming reaction unit, said shift reaction unit and said CO oxidation unit is formed into a coil-like shape. 
     
     
       22. The reforming apparatus according to  claim 19 , further comprising an air feed channel for introducing fresh air into said second duct. 
     
     
       23. The reforming apparatus according to  claim 1 , wherein at least a portion of a raw material feed channel for feeding the raw material and steam to said raw material reforming unit is arranged in a position in which the raw material and the steam are preheated by heat from the heat source of said raw material reforming unit. 
     
     
       24. The reforming apparatus according to  claim 23 , wherein at least a portion of said raw material feed channel is held in contact with the surface of at least one of said reforming reaction unit, said shift reaction unit add  and said CO oxidation unit. 
     
     
       25. The reforming apparatus according to  claim 23 , wherein at least a portion of said raw material feed channel is arranged at a position able to be contacted with the burned exhaust gas from the heat source to said raw material reforming unit. 
     
     
       26. The reforming apparatus according to  claim 23 , wherein at least a portion of said raw material feed channel is arranged at such a position that it can be directly heated by the heat source of said raw material reforming unit. 
     
     
       27. The reforming apparatus according to  claim 1 , wherein at least a portion of a fuel feed channel for feeding fuel to the heat source of said raw material reforming unit is arranged at a position able to be preheated by heat from the heat source of said raw material reforming unit. 
     
     
       28. The reforming apparatus according to  claim 1 , further comprising a combustion catalyst held in said heat source and a preheater for preheating the combustion catalyst, wherein the heat source of said raw material reforming unit generates heat by catalytic combustion. 
     
     
       29. A reforming apparatus comprising an integrated structure of four separate units, which comprises:
 a combustion unit for generating heat by combustion of a fuel gas;  
 a raw material reforming reaction unit for steam-reforming a raw material and producing a reformed gas containing hydrogen as a principal component;  
 a shift reaction unit for decreasing CO contained in the reformed gas, that was produced in said raw material reforming unit, by water-gas-shift reaction;  
 a CO oxidation unit for further decreasing CO contained in the resultant reformed gas, that was treated in said shift reaction unit, by oxidation;  
 said reforming reaction unit and said shift reaction unit containing different catalysts, said shift reaction unit and said CO oxidation unit being indirectly heated by heat transfer from the heat source of said raw material reforming unit, said CO oxidation unit being positioned outside said reforming reaction unit, and said reforming reaction unit being directly heated by said combustion unit so that the temperature in said reforming reaction unit is controlled in the range of 400 to 1000° C., said shift reaction unit being indirectly heated by heat transfer from said combustion unit so that the temperature in said shift reaction unit is controlled in the range of 200 to 350° C., said CO oxidation unit being indirectly heated by heat transfer from said combustion unit so that the temperature in said CO oxidation unit is controlled in the range of 100 to 250° C.;  
 said CO oxidation unit including an outside surface, and being arranged to obtain atmospheric cooling of the outside surface; and  
 said raw material reforming unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to each other with said CO oxidation unit placed on an outer peripheral side of the reforming apparatus.  
 
     
     
       30. A reforming apparatus comprising an integrated structure of three separate units, comprising:
   a raw material reforming unit for steam - reforming a raw material to be reformed and producing a reformed gas containing hydrogen as a principal component, including a heat source that generates heat by combustion of a fuel gas, operable to directly obtain heat for the steam reformation reaction from said heat source;        a shift reaction unit for decreasing, by water - gas - shift reaction, CO contained in the reformed gas produced in said raw material reforming unit; and        a CO oxidation unit for further decreasing, by oxidation, CO contained in reformed gas treated in said shift reaction unit;        said raw material reforming unit and said shift reaction unit contain different catalysts, and said shift reaction unit and said CO oxidation unit being arranged in a manner that said shift reaction unit and said CO oxidation unit can be indirectly heated by heat transfer from the heat source of said raw material reforming unit, and further said CO oxidation unit including an outside surface, and being arranged to be cooled by at least one of atmospheric cooling and a combination of raw material and water cooling of the outside surface; and        said raw material reforming unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to each other with said CO oxidation unit placed on an outer peripheral side of the reforming apparatus.     
     
     
       31. The reforming apparatus according to  claim 30 , wherein said raw material reforming unit comprises a generally cylindrical combustion chamber as the heat source and a reforming reaction unit for steam- reforming the raw material to produce the reformed gas containing hydrogen as a principal component, said reforming reaction unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to said combustion chamber.   
     
     
       32. The reforming apparatus according to  claim 31 , wherein said reforming reaction unit is concentrically accommodated within said combustion chamber. 
     
     
       33. The reforming apparatus according to  claim 31 , wherein said reforming reaction unit is positioned outside said combustion chamber in contact therewith. 
     
     
       34. The reforming apparatus according to  claim 31 , said combustion chamber comprising a center, and further comprising an incombustible core arranged at the center of said combustion chamber. 
     
     
       35. The reforming apparatus according to  claim 31 , wherein both of said shift reaction unit and said CO oxidation unit are positioned outside said reforming reaction unit. 
     
     
       36. The reforming apparatus according to  claim 35 , further comprising a partition wall having a function of regulating heat transfer, the partition wall being interposed between said reforming reaction unit and both of said shift reaction unit and said CO oxidation unit. 
     
     
       37. The reforming apparatus according to  claim 35 , wherein said reforming reaction unit and said shift reaction unit are connected by a flow path detouring outside both of said shift reaction unit and said CO oxidation unit. 
     
     
       38. The reforming apparatus according to  claim 35 , wherein said shift reaction unit is arranged on a side adjacent to a high temperature zone of said reforming unit and said CO oxidation unit is arranged on a side adjacent a low temperature side of said reforming reaction unit, so as to be in conformity to a temperature distribution within said reforming reaction unit. 
     
     
       39. The reforming apparatus according to  claim 30 , wherein each of said shift reaction unit and said CO oxidation unit is arranged in a position which is heated by a burned exhaust gas from said heat source of said raw material reforming unit. 
     
     
       40. The reforming apparatus according to  claim 30 , wherein said CO oxidation unit is arranged to be cooled by raw material and water cooling of the outside surface. 
     
     
       41. A reforming apparatus comprising an integrated structure of four separate units, which comprises:
   a combustion unit for generating heat by combustion of a fuel gas;        a raw material reforming reaction unit for steam - reforming a raw material and producing a reformed gas containing hydrogen as a principal component;        a shift reaction unit for decreasing CO contained in the reformed gas, that was produced in said raw material reforming unit, by water - gas - shift reaction;        a CO oxidation unit for further decreasing CO contained in the resultant reformed gas, that was treated in said shift reaction unit, by oxidation;        said reforming reaction unit and said shift reaction unit containing different catalysts, said shift reaction unit and said CO oxidation unit being indirectly heated by heat transfer from the heat source of said raw material reforming unit, said CO oxidation unit being positioned outside said reforming reaction unit, and said reforming reaction unit being directly heated by said combustion unit so that the temperature in said reforming reaction unit is controlled in the range of  400  to  1000 ° C., said shift reaction unit being indirectly heated by heat transfer from said combustion unit so that the temperature in said shift reaction unit is controlled in the range of  200  to  350 ° C., said CO oxidation unit being indirectly heated by heat transfer from said combustion unit so that the temperature in said CO oxidation unit is controlled in the range of  100  to  250 ° C.;        said CO oxidation unit including an outside surface, and being arranged to be cooled by at least one of atmospheric cooling and a combination of raw material and water cooling of the outside surface; and        said raw material reforming unit, said shift reaction unit and said CO oxidation unit are concentrically arranged relative to each other with said CO oxidation unit placed on an outer peripheral side of the reforming apparatus.     
     
     
       42. The reforming apparatus according to  claim 41 , wherein said CO oxidation unit is arranged to be cooled by raw material and water cooling of the outside surface.