烟气脱硫用胺液中热稳定盐的分析及脱除

Analysis and removal of TSS accumulated in amine absorption solution for removing SO_2 from flue gas

在可再生湿法烟气脱硫工艺中,针对吸收剂胺液中热稳定盐累积而影响工艺过程长周期操作的问题,分析了侧线试验中吸收剂胺液中热稳定盐含量随时间的变化,得到了热稳定盐的累积规律;通过对净化前后催化裂化烟气组成的分析,预测了吸收剂中热稳定盐可能存在的类型为硝酸盐、亚硝酸盐、硫酸盐、硫代硫酸盐和连二硫酸盐等物质,且硫酸盐是热稳定盐的主要成分;根据预测的热稳定盐类型,测定了六种不同类型离子交换树脂对四种吸收剂样品的净化效果,筛选出适于胺液吸收剂净化的离子交换树脂为D型离子交换树脂。

In the Regenerable Absorption Process for SOx Cleanup, it was found that the accumulation of thermal stable salts （TSS） in amine absorption solution will affect the long-term operation of process. Based on the composition analysis of amine absorption solution, the accumulation law of TSS was summarized. The pos- sible types of TSS, i.e. nitrate, nitrite, sulfate, thiosulfate and dithionate, etc were predicted. The main type of TSS was sulfate from the analysis of compositions of FCC flue gas before and after absorption. Based on above analysis, six types of ion exchange resins were selected to remove TSS from amine absorption solution. In the performance evaluation experiments, the anion exchange resin, i.e. resin D, was found to be the proper type of ion exchange resin for purification of amine absorption solution.