加入甲烷促进选择性非催化还原反应的实验研究

Experimental Investigations of Enhanced Selective Non-catalytic Reduction Reaction With Methane

为研究甲烷对选择性非催化还原（SNCR）脱硝反应的影响作用，在沉降炉实验台上模拟锅炉烟道内的反应环境和烟气成分，在650～1150℃范围内，研究了微量甲烷对SNCR反应温度窗口、脱硝效率和氨泄漏的影响，以及甲烷在脱硝过程中的反应特性。实验结果表明，在SNCR反应过程中加入少量的甲烷，可以降低并拓宽其反应温度窗口，提高较低温度下的脱硝率。同时促进氨的反应活性，降低氨泄漏，提高氨利用效率。而且加入甲烷后脱硝反应速率加快，使反应所需时间缩短，但使最大脱硝效率稍有降低。增加脱硝反应中的喷氨量，可拓宽脱硝反应温度窗口并提高脱硝效率。脱硝反应中加入的甲烷在950℃左右基本消耗完，不产生二次污染。

To study the influences of methane on selective non-cataJytic reduction （SNCR）, the condition of flue gas composition was simulated on a drop tube furnace test rig, and the influences of a few of methane on SNCR temperature window, NOx reduction efficiency and ammonia slip from 650℃ to 1 150 ℃ were investigated, as well as reactivity of methane. Experimental results indicate that a few of methane additive to SNCR reaction could depress and widen the reaction temperature window, and increase DeNOx efficiency at lower temperature. At the same time, ammonia reactivity is promoted and ammonia utility is improved which causes reduction of ammonia slip. Further more, the reaction speed would be fastened, and the residence time to complete reaction is shortened. However the maximal NOx reduction efficiency decreases a little. Increase of ammonia could widen the temperature window and enhance NOx reduction efficiency. Methane injected into SNCR reaction would be depleted at 950℃ bringing no second pollution.