胺法脱二氧化硫溶液中热稳定性盐去除实验研究

针对烧结烟气可再生胺法脱硫工艺,脱硫溶液中SO42-等酸根离子累积量大、累积速度快,生成的热稳定性盐必须去除以保持脱硫溶液的脱硫性能。采用石灰乳化学沉淀法、冷冻结晶法、离子交换树脂吸附法、冷冻结晶+离子交换树脂吸附法对脱硫溶液中SO42-等酸根离子进行了去除实验研究,结果表明:石灰乳化学沉淀法对SO42-去除率为68.51%左右,SO32-的去除率达到97.46%以上;冷冻结晶法,在7℃下,Na+与SO42-摩尔比为1.61时,SO42-去除率为86.45%,Na+浓度为11.8g/L;离子交换树脂吸附法对SO42-的去除率均低于石灰乳、冷冻结晶法对SO42-的去除率,同时Cl-、NO3-等酸根离子也被树脂吸附;冷冻结晶+离子交换树脂吸附法对SO42-、Cl-、NO3-等酸根离子去除率高,效果明显好于单独采用离子交换树脂吸附法。

Study on removal of HSS from organic amine SO2 scrubbing solution

In the regenerable amine flue gas desulfurization(FGD) process,great amount of acid radical ions such as SO42-cumulates rapidly in the amine scrubbing solution and the formed heat stable salts(HSS) must be removed to maintain the high desulfurization performance of the scrubbing solution.The desalination methods,including chemical precipitation,cooling crystallization,ion exchange resin adsorption and the combination of the later two,were studied for removal of the HSS.Experimental results show that chemical precipitation could remove SO42-of 68.51% and SO32-of above 97.46%;cooling crystallization could remove SO42-of 86.45% at 7℃ in Na+/SO42-molar ratio of 1.61;ion exchange resin adsorption couldn't effectively remove SO42-from high concentration solution,but considerable Cl-and NO3-could be adsorbed by the resin;and cooling crystallization combined with resin adsorption could effectively remove SO42-,Cl-,NO3-and other HSS,obviously better than only resin adsorption.