次氯酸钙溶液脱硫脱硝一体化过程热力学分析

Thermodynamics Analysis of Integrated Process for Simultaneous Desulfurization and Denitrification with Calcium Hypochlorite Solution

烟气脱硫脱硝一体化技术已成为当前大气污染防治领域的研究热点,其中氧化剂液相吸收法极有可能率先实现产业化。文章理论上首次提出了次氯酸钙溶液脱硫脱硝一体化技术,利用热力学函数计算分析了脱硫脱硝反应的方向和限度,通过SO2和NO平衡分压计算推导了污染物的脱除效率,考察标准吉布斯函数变分析了该技术的优势。结果表明:脱硫脱硝反应的标准吉布斯函数变分别为-614.55和-888.21 kJ/mol,热力学角度上完全可行,反应限度极深,优于文献中介绍的尿素、NaClO2、KMnO4/NaOH溶液吸收法和臭氧结合氨水吸收法。同时,SO2和NO平衡分压很小,说明次氯酸钙溶液几乎可以完全脱除烟气中的SO2和NOX。

The study of integrated process for simultaneous desulfurization and denitrification currently becomes the hotspot of air pollution control. Oxidant-aqueous method will be likely to first realize industrialization. Using calcium hypochlorite solution to remove SO~ and NOx in flue gas simultaneously is for the first time proposed theoretically. The direction and limitation of desulfurization and denitrification reaction were studied by calculating thermodynamic function. The pollutant removal efficiencies were deduced by calculating equilibrium partial pressure of SO2 and technology advantages were analyzed by comparing the changes of standard Gibbs function of desulfurization and denitrification reaction from various documentations. Results showed that the integrated process for simultaneous desulfurization and denitrification with Ca（CIO）2 solution are thermodynamically feasible, the limitations are extremely deep, the standard Gibbs function changes are -614.55 and -888.21 kJ/mol respectively, lower than those of using urea, NaClO2, KMnO4/NaOH solution and NH3·H2O absorption combined with ozone oxidation. The equilibrium partial pressure of SO2 and NO are quite small, indicating SO2 and NOx in flue gas could be almost completely removed.