基于超稳低汞触媒的万吨级氯乙烯单体无汞排放生产工艺

Production process for 10000 ton vinyl chloride monomer without mercury emission based on ultra stable low mercury catalyst

为了减少汞触媒的流失和污染,解决触媒倒台问题,设计了2种不同型号的超稳低汞触媒ZH-1F和ZH-1B,并分别装填前台转化器和后台转化器。对运行过程中的技术参数及汞流向进行了监测和衡算。根据运行结果,新型超稳低汞触媒在前台、后台转化器乙炔空速为60~80 h^(-1)及反应温度为160~180℃的高温高负荷运行条件下,均可连续运行8500 h以上。转化器出口气体中的汞含量低于国标汞排放标准。前台转化器氯乙烯单体生产能力达1.8万t,触媒单耗(以生产1 t PVC计)可低至0.4 kg以下。使用超稳低汞触媒并采用新的装填方案,基本可以解决汞触媒使用过程中的汞流失问题,实现99%以上的汞回收。

In order to reduce the loss and pollution of mercury catalysts and to solve the problems in catalyst rotation,two different models of ultra stable low mercury catalysts ZH-1F and ZH-1B were designed and installed in the front and in the back converters,respectively.The technical parameters and mercury flow direction during operation were monitored and calculated.According to the operating results,the new ultra stable low mercury catalyst could operate continuously for more than 8500 h under high temperature and high load operating conditions of acetylene space velocity of 60-80 h and 160-180℃ in both the front and back converters.The mercury content in the gas at the outlet of the converter was lower than the national mercury emission standard.The production capacity of vinyl chloride monomer in the front converter reached 18000 t,and the catalyst consumption per unit(calculated based on the production of 1 t of PVC)could be as low as 0.4 kg or less.The use of ultra stable low mercury catalysts and new filling schemes could basically solve the problem of mercury loss during the use of mercury catalysts,achieving over 99%mercury recovery.