摘要
一氧化氮(NO)是燃煤锅炉烟气中的主要污染物,因其是酸雨和光化学烟雾的前体物而受到广泛关注。采用作为氧化剂开展了其对模拟烟气中NO的氧化去除研究,并分析了氧化脱硝反应的热力学过程以及NO从气相主体到液相主体的传质过程。结果显示:以为氧化剂氧化NO的总反应吉布斯自由能为-659.69 k J·mol^(-1),小于零,说明该反应是自发过程;气液传质分析表明NO气体的吸收传质速率主要由液膜控制。实验采用添加Fe(Ⅱ)ED-TA的方法增大化学反应对液相传质速率的放大系数,致使液膜传质阻力减小,从而使NO的去除率从30%提高至91.6%。该结果为湿法氧化脱硝工艺的后续研究和应用提供了理论参考和技术支持。
As a kind of air pollutant in coal-fired flue gas, nitric oxide （NO） not only promotes the formation of acid rain but also contributes to the photochemical smog. Nowadays, Denitrification gains more and more attention. The oxidation of NO by K2S2O8 was studied in a lab-scale bubble reactor. The thermodynamic process of oxidation was researched, and the mass transfer of NO from gas phase to liquid phase was analyzed as well. Results showed that Gibbs free energy of the integrated reaction was -659.69 kJ·mol-1, which indicated the process of K2S2O8 oxidizing NO was spontaneous. Analysis on mass transfer suggested that the absorption rate of NO was mainly influenced by liquid membrane. Magnification factor of mass transfer rate in liquid phase could be promoted by adding Fe（Ⅱ）EDTA to K2S2O8 solution in this experiment, which led to the decrease of mass transfer resistance in the liquid membrane. Thus, the removal rate of NO increased from 30% to 91.6%. The results offer theoretical references and technical supports to the application of wet denitrification with K2S2O8.
出处
《环境工程学报》
CAS
CSCD
北大核心
2017年第12期6351-6358,共8页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(50677026)
武汉市应用基础研究计划项目(2015060101010068)
