火电厂烟气脱硫的己二酸-硫酸钠复合添加剂研究

Development of adipic acid-sodium sulfate compositing additive for thermal power plant flue gas desulfurization

研究单一有机羧酸和己二酸-硫酸钠复合添加剂对石灰石浆液的促溶作用以及pH缓冲作用;基于石灰石-石膏湿法脱硫模拟实验装置测试己二酸和复合添加剂强化湿法烟气脱硫的效率,分析入口SO2浓度、液气比分别对脱硫率的影响.结果表明:己二酸对石灰石浆液的促溶作用和pH缓冲作用强于大多数单一有机羧酸;己二酸-硫酸钠复合添加剂对浆液的促溶作用强于单一己二酸而pH缓冲作用相差不大;当入口SO2浓度为1 608mg/m3,液气比为4.5L/m3以及其他条件一定时,5mmol/L己二酸+0.02mol/L硫酸钠的复合添加剂效果最好,其脱硫效率可达95.4%,比石灰石空白试验提高11.3%,较5mmol/L己二酸强化提高5.3%,且能使石灰石的利用率提高大约50%.在益阳电厂工况条件下测试复合添加剂效果,达到了新的GB 13223-2011《火电厂大气污染物排放标准》中"新建锅炉SO2排放限值≤100mg/m3"的要求.

The effect of a single organic carboxylic acid and adipic acid-sodium sulfate compounding additives for promoting dissolution and buffering pH on limestone slurry was analyzed in this paper. The desulfurization efficiencies of the adipic acid and the compounding additive were investigated in a limestone-gypsum desulfurization simulation device. Each influence of inlet SO2 concentration and liquid-gas ratio on the desulfurization efficiency was tested in the device. Results showed that the effect of adipic acid for both promoting dissolution and buffering pH on limestone slurry is stronger than that of most single organic carboxylic acid; the effect of adipic acid-sodium sulfate compounding additives for promoting dissolution is stronger than that of the single adipic acid, however, their effect for buffering pH on limestone slurry have little difference; when the inlet SO2 eoncentration is 1608 mg/m3 , liquid-gas ratio is 4.5 L/ma and the other condition are certain, the effect of the compounding additive of 5mmol/L adipic acid and 0.02 mol/L sodium sulfate is the best, and its desulfurization degree can reach to 95. 4%, which is increased by 11. 3% compared to blank test and 5.3% compared to 5 mmol/L adipic acid, also the limestone utilization is increased by 50 % in the WFGD. The compounding additive was tested in the original working conditions of Yiyang power plant. Results showed it can meet the requirements for ＂ SO2 emission limits of new boiler ≤ 100 mg/m3 ＂ in new ＂GB13223--2011 thermal power plant air pollutant emission standards＂.