电厂用阳离子交换树脂高温分解特性研究

Study of the Pyrolytic Characteristics of Power-plant-purposed Cation Exchange Resin

漏入热力系统破碎阳树脂的高温分解是电站水汽系统SO24-含量超标的原因之一。针对这一问题,采用高压釜实验对几种凝结水精处理常用阳树脂的SO24-高温分解特性进行了研究。结果表明:阳树脂高温分解后其交换基团(—SO3H)会从树脂骨架上脱落并产生SO24-,其分解产生SO42-的量随分解温度的升高而增大,当温度超过200℃后会出现骤增现象,并产生大量酸性物质;旧树脂分解产生SO42-的量略小于新树脂,但会产生更多的酸性物质;在280℃条件下,阳树脂分解产生SO42-的量随时间的增加而增加,实测SO42-结果与红外光谱检测结果都表明某些树脂分解24 h后几乎达完全分解。

The pyrolysis by SO2-4 leaked into a thermal system to break up cation resin represents one of the causes that the SO2-4 content in a water-steam system of a power plant exceeds the standard.To solve such a problem,the authors have studied the SO2-4 pyrolysis characteristics of the commonly-used cation resin polished by condensate water in an autoclave.The research results show that after a pyrolysis of the cation resin,its exchange functional group(-SO3H) will fall off from the resin skeleton and produce a great quantity of acidic substances.The quantity of SO2-4 produced by the pyrolysis will increase with the pyrolytic temperature and a surge phenomenon will emerge after the temperatue exceeds 200 ℃.The quantity of SO2-4 produced by the old resin will be slightly less than that produced by the new resin,however,more acidic substances will be generated.At 280 ℃,the quantity of SO2-4 produced by the cation resin will increase with an elapse of time.Both actually measured SO2-4 and the result obtained from the infrared spectrum show that a certain quantity of resin is almost completely decomposed after 24 hours.