NaClO_2碱性溶液脱硝的热力学计算与实验研究

液相氧化脱硝技术被认为是最有前景的脱硝技术之一。在自制的鼓泡反应器中,进行NaClO2/NaOH溶液脱硝实验。热力学计算表明,300~380K,脱硝反应是放热反应,反应的平衡系数均非常大,但随温度的升高而减小。选取吸收时间、NaClO2浓度、初始、反应温度、模拟烟气流量以及烟气中pHNO含量为过程参数,脱硝率作为响应量,分别进行了单因素实验。结果表明:脱硝率随NaClO2浓度、反应温度的增加而升高,随吸收时间、烟气流量或NO含量的增加而降低,在pH7~10范围内,体系获得较好的脱硝效果;NaClO2浓度,初始0.02mol/LpH,10温度70℃,烟气流量0.4L/min的条件下,处理NO含量0.02%~0.05%范围内的烟气,吸收20min内体系脱硝率几乎为100%。

Thermodynamic Calculation and Experimental Investigation about the Denitrification by NaClO2 Alkaline Solution

Liquid-phase oxidation denitrification technology is one of the most perspective technologies. This work carried out the experiments by using NaClO_2/NaOH solution in self-made bubbling reactor. Thermodynamic calculation showed that at 300~380K, the denitrification reaction was exothermic reaction, the equilibrium coefficients of the reaction were all very big, and decreased gradually as the temperature increased. Absorption time, NaClO_2 concentration, initial pH, reaction temperature, simulated gas flux and concentration of NO were selected as the process parameters, denitrification rate as the response, carried out the single-factor experiments. Experimental results demonstrated that: the denitrification rate rose while the NaClO2 concentration or reaction temperature increased, and decreased while the absorption time, gas flux or the NO concentration increased. During the pH 7~10, better effect was achieved. On the condition of the NaClO_2 concentration 0.02mol/L, initial pH 10, temperature 70℃, and gas flux 0.4 L/min, disposing simulated gas whose NO concentration range was 0.02% ~0.05%, within 20 min, the denitrification rate was nearly 100%.