循环流化床烟气SNCR脱硝机理与实验

Denitrification Mechanism Analysis and Experiment of Selective Non-Catalytic Reduction of Flue Gas of Circulating Fluidized Bed

采用电加热循环流化床锅炉模拟实际烟气,在炉膛出口喷入氨水或同时添加H2、CH4进行脱硝,实验结果表明:最佳停留时间、氨氮物质的量之比分别为0.6,s和1.5,氨水最佳反应温度为920,℃,添加H2最佳温度降低至750,℃,添加CH4最佳温度降低至840,℃.同时为深入认识其化学反应规律,采用基元反应动力学模型对氨水与NOx反应进行了模拟计算,模拟结果表明,该基元反应模型较好地解释了反应机理.

In this work, simulated circulating fluidized bed （CFB） flue gas was fed into an electricity-heated tubular flow reactor, and ammonia was injected into the flue gas as a reducing agent. Besides, H2 or CH4 was added to the flue gas for denitrification and its effects on selective non-catalytic reduction （SNCR） process were explored. Experimental results show that the maximum reduction was achieved at the optimal temperature of 920℃, with the residence time of 0.6 s and a normalized NH3/NOx stoichiometric ratio of 1.5. The optimal temperature is reduced to 750 ℃ with H2 as an additive and to 840 ℃ with CH4 as an additive. Besides, in order to explore the reaction characteristics of SNCR and SNCR with H2 or CH4 addition, the chemical reaction mechanism was analyzed by one business software. By comparison between the experimental data and the calculation results, the selected mechanism was found to be agreeable in forecasting the process.