生物质再燃脱硝的试验研究

采用恒温沉降炉研究了秸秆、稻壳2种生物质及一种煤粉作为再燃燃料的NO还原特性，针对燃料种类、过量空气系数、停留时间及再燃比例4个因素的改变对脱硝率的影响进行了实验研究，同时对3种燃料的再燃燃尽特性进行了分析。研究表明：生物质脱硝能力明显高于煤粉，提高再然比例及减小过量空气系数，3种燃料的脱硝率有不同程度的提高，其中秸秆脱硝率最高，稻壳中等，煤粉最低；在一定的再燃停留时间内(650 ms)，延长停留时间，脱硝率增加，超过这一停留时间，脱硝率增加缓慢。生物质与煤粉相比，在相同反应条件下能获得更高的脱硝效果，同时其不完全燃烧损失保持在合理的范围内。

Experimental Studies on Reburning With Biomass for NOx Reduction

Nitric oxide (NO) reduction process by reburning with two kinds of biomasses corn straw, rice husk and one pulverized bituminous coal were studied in an isothermal high temperature drop tube furnace (DTF). Experimental studies were performed on influences of NO removal efficiency by fuel type, excess air ratio (SR), resident time, and reburning fuel fraction. Meanwhile, burnout of three reburning fuels was analyzed. The results show that biomass owns higher NO removal efficiency than pulverized coal. NO removal efficiency of three kinds of fuels increases by different extent through the increase of reburn fuel fraction and the decrease of the excess air ratio. NO removal efficiency of corn straw is the most efficient; rice husk is medium, pulverized bituminous coal is the lowest. Within the certain reburn resident time (650 ms), NO removal efficiency increases quickly with the resident time. Beyond this resident time limit, NO removal efficiency increase slowly. In the tested conditions, biomass was more efficient than pulverized bituminous coal for NO removal efficiency and unburnt carbon in fly ash was within reasonable limits.