| 摘要 |
<p>PURPOSE:To prevent substances from adhering to a catalyst layer and dispose of combustion exhaust gas at low cost in a process of reducing the exhaust gas in contact with ammonia, by adding ammonia, collecting dusts and thereafter denitrificating the gas by a catalyst which is low in SO2-oxidizing power. CONSTITUTION:Exhaust gas from a coal combusion boiler or the like, which contains a large amount of dusts and contains nitrogen oxides, oxygen and sulfur oxides, is reduced in contact with ammonia. The ammonia is added to the exhaust gas having a low temperature of 100-300 deg.C, thereby changing the sulfuric anhydride in the exhaust gas into ammonium sulfate. After the exhaust gas is removed of the ammonium sulfate and the dusts by an electric dust collector, the gas is denitrificated by a catalyst which has a denitrification property at 200-300 deg.C and is very low in activity to change SO2 into SO3. The ammonium sulfate and the dusts are thus prevented from adhering to the catalyst layer. This results in stably disposing of the exhaust gas at low cost for a long time.</p> |
