三聚氯氰尾气中资源回收及尾气合成次氯酸钠工艺研究

针对三聚氯氰生产过程中氯氰单体聚合生成三聚氯氰后尾气处理成本高、三废多等问题,采用冷凝回收尾气中氯化氰与合成次氯酸钠的方式对尾气进行资源化处理。三聚氯氰尾气通过布袋除尘器除去固体杂质,进一步通过冷却换热器将尾气中未反应氯化氰冷凝,回用至体系中作为合成三聚氯氰原料。冷凝后尾气通入20%氢氧化钠溶液中,尾气中的氯气与氢氧化钠反应,得到次氯酸钠溶液。研究了布袋除尘器和冷凝器的效果,以及氢氧化钠浓度、游离碱对次氯酸钠中有效氯和稳定性的影响。结果表明,布袋除尘器和冷凝器能够有效去除固体和气体有机物,氢氧化钠质量浓度为20%、游离碱为1%时,次氯酸钠中有效氯能够达到产品指标要求,且稳定性较好,实现了三聚氯氰尾气的资源回收和价值提升。

RESOURCE RECOVERY AND SYNTHESIS OF SODIUM HYPOCHLORITE FROM TAIL GAS OF CYANURIC CHLORIDE

To solve problems of high cost of tail gas treatment and excessive waste after the polymerization process of cyanogen chloride, a method of condensation recovery of cyanogen chloride in tail gas and synthesis of sodium hypochlorite was Proposed. The solid impurities in the tail gas was removed through a bag dust remover and the unreacted cyanide chloride in the tail gas was condensed through cooling the heat exchanger. After condensation, the tail gas is injected into 20% sodium hydroxide solution, and the chlorine gas in the tail gas reacts with sodium hydroxide to obtain sodium hypochlorite solution. The effects of bag dust remover and condenser, concentration of sodium hydroxide and free alkali on effective chlorine and stability of sodium hypochlorite were studied. The results show that the bag dust remover and condenser can effectively remove solid and gas organic matter. When the concentration of sodium hydroxide is 20% and the free base is 1%, the effective chlorine in sodium hypochlorite can meet the requirements of product index value, and the sodium hypochlorite is stable.