| 摘要 |
PROBLEM TO BE SOLVED: To efficiently and selectively oxidize carbon monoxide even when the amount of a gas to be treated fluctuates or when the concentration of carbon monoxide contained in the gas to be treated changes. SOLUTION: An apparatus 20 for selectively oxidizing and removing carbon monoxide is constituted by successively arranging first, second and third selective oxidation/ removal sections 21, 22 and 23 in series in the flow direction of a reformed gas. The selective oxidation/removal sections 21, 22 and 23 are each constituted by providing a heat exchange part 11, an air supplying part 12, and a gas mixing part 13 and further, a first catalyst part 34, a second catalyst part 44 and a third second catalyst part 54, respectively, in sequence to the flow direction of the reformed gas. Catalyst layers 34a, 44a and 54a, each obtained by supporting a catalyst metal such as Pt onto an alumina carrier and forming the resulting alumina carrier into a honeycomb structure, are provided in the catalyst reaction parts 34, 44 and 54, respectively. The amount of catalyst metal supported on unit volume in each catalyst layer 34a, 44a or 54a is made same and when the lengths of catalyst layers 34a, 44a and 54a in the flow direction of the reformed gas are each defined as L1, L2 and L3, the L1, L2 and L3 are set so as to satisfy following relation: L1<L2<L3. |
