| 摘要 |
<p>PURPOSE:To denitrate efficiently NO2 in NOx-contg. gas without by-producing N2O by reducing at least a part of NO2 in said gas to NO then subjecting the same to a denitration treatment by an ammonia catalytic reduction method. CONSTITUTION:The NOx-contg. gas which contains the NO2 introduced through a line 1 is heated to a prescribed temp. with a heater 5 and is then introduced into an NO2-NO converter 6. The above-mentioned gas is brought into contact with a catalyst 9 contg. the oxide of metal such as Co as an active component in said converter, so that at least a part of NO2 is reduced by a reducing agent such as H2 and is converted to NO, thereby decreasing the ratio of NO2 in the NOx to more preferably <=50%. NH3 is added to said gas through a line 7 and the gas is introduced into a denitration reactor 8. The gas is brought into contact with a catalyst 10 combined with the oxides of Ti, V, Mo and W in said reactor and NO2 is denitrated with high efficiency by reduction reaction.</p> |
