原著論文
触媒燃焼による燃料改質ガス由来排気中残存メタンの効率的除去に関する研究
2010 年 52 巻 159 号 p. 76-85
詳細
2010 年 52 巻 159 号 p. 76-85
Catalytic combustion method was studied to remove CH4 efficiently in the off-gas from fuel reforming type FC system. The higher temperature was necessary to remove CH4 by using the combustion catalysts so that the off-gas contained relatively high degree of moisture. The effective removal of CH4 under the condition of lower temperature was possible according to the O2 control method which adjusted O2 amount to lower than the stoichiometry of CH4 oxidation. In this case, H2 and CO were detected in the catalyst outlet gas, so it has been understood that the partial oxidation reaction has occured. The catalyst surface was thought to adsorb O2 easily than CH4, and the O2 covered the catalyst surface, therefore the CH4 combustion was inhibited when the amount of O2 increased. The O2 control method was thought to be effective to exclude the inhibition. Coexisting H2 in the off-gas raised the catalyst bed temperature by the H2 oxidation so that it promoted the CH4 conversion. The influence of CH4 concentration was also discussed. The comparison was made with data for Pd and Pt catalyst performance. The effects of loading amount of Pd on the catalyst performance were discussed, and it was suggested that the H2 and CO oxidation, CO shift reaction and steam reforming could be occurred following the partial oxidation of CH4. So it is important to promote the series of these reactions for the efficient removal of residual CH4 in the wasted gas.
