CLEANING AGENT CONSISTING OF SILVER CATALYST AND SILVER, IRON AND COPPER CATALYST FOR EXHAUST GAS AND CLEANING METHOD OF EXHAUST GAS USING ETHANOL

摘要

PROBLEM TO BE SOLVED: To efficiently remove nitrogen oxide from a combustion exhaust gas containing a larger amt. of oxygen than the stoichiometric amt. by depositing a specified amt. of one or more kinds selected from silver and silver compds. on a porous inorg. oxide to prepare first and second catalysts and depositing each specified amt. of iron oxides and copper oxides on the second catalyst. SOLUTION: The first catalyst is prepared by depositing one or more kinds selected from silver and silver compds. on a porous inorg. oxide. the amt, of the silver component deposited is 0.2 to 15wt.% (calculated as silver element) to 100wt.% porous inorg. oxide. The second catalyst is prepared by depositing one ore more kinds selected from silver and silver compds. by 0.2 to 15wt.% (calculated as silver element) and iron oxides and copper oxides by each 0.1 to 30wt.% (calculated as each metal element) on 100wt.% porous inorg oxide. The first and second catalysts are disposed in a conduit for exhaust gas in such a manner that the first catalyst is arranged in the entrance side of the cleaning material for the exhaust gas where the gas flows and that the second catalyst is disposed on the exit side of the flow.