ClO_2气相氧化联合CaCO_3浆液吸收同时脱硫脱硝试验研究

Experimental research of simultaneous desulfurization and denitrification by ClO_2 gas phase oxidation combining with CaCO_3 slurry absorption

采用ClO_2气相氧化联合CaCO_3浆液吸收工艺对模拟烟气进行同时脱硫脱硝,研究了ClO_2/NO摩尔比、SO_2初始浓度对气相氧化段NO氧化率的影响及液相吸收段中CaCO_3浆液pH、温度和液气比对同时脱硫脱硝效果的影响。结果表明,在气相氧化段,NO的氧化率随着ClO_2/NO摩尔比的增加呈先快速增加后逐渐平稳的变化趋势;在给定的ClO_2/NO摩尔比(0.8)下,随着SO_2初始浓度的增加,NO氧化率稍有下降,高浓度SO2的存在对ClO_2氧化NO的抑制作用有限,说明ClO_2对NO的氧化反应具有良好的选择性。ClO_2气相氧化联合CaCO_3浆液吸收工艺最优反应条件:ClO_2/NO摩尔比为0.8,CaCO_3浆液初始pH为7.0、温度为55℃,液气比为18L/m3。当SO2初始质量浓度为1 000 mg/m^3、NO_x初始质量浓度为509 mg/m3时,最佳反应条件下SO_2去除率达100.00%,NO_x去除率达81%左右。

Simultaneous desulfurization and denitrification of simulated flue gas was carried out by combining ClO2 gas phase oxidation and CaCO3 slurry absorption process. The influence of the ClO2/NO molar ratio and the SO2 initial concentration on the oxidation efficiency of NO in the gas phase oxidation section and the effect of the pH and temperature of CaCO3 slurry absorbent, liquid to gas ratio on the desulfurization and denitrification efficiency were studied. The results show that in the gas phase oxidation section, the oxidation rate of NO was increased first and then steadily with the increase of ClO2/NO molar ratio. With the increasing of the initial SO2 concentration, the oxidation rate of NO decreased slightly under the given ClO2/NO molar ratio （0.8） , means the existence of high concentrate S0 2 had little effect on NO oxidation by ClO2 , which indicated that ClO2 had good selectivity for the oxidation of NO. When the initial concentration of SO2 was 1 000 mg/m^3 ,the initial concentration of NOx was 509 mg/m^3 ,the optimal reaction conditions of combining ClO2 gas phase oxidation and CaCO3 slurry absorption process were as follows： the ClO2 /NO molar ratio was 0.8,the initial pH of CaCO3 slurry was 7 .0 , the temperature was 55 ℃ ,the liquid gas ratio was 18 L/m^3. Under these optimal conditions, the desulfurization rate reached 100.00% and the denitrification rate was about 81 %.