两步沉淀法处理乙烯废碱液的实验研究

Study on two-step treatment of spent caustic water from ethylene cracking

采用苛化及化学沉淀两步工艺对乙烯裂解废碱液的再生进行了研究,考察了影响再生效果的各种条件因素。结果表明:苛化反应温度大于 80℃,反应时间超过 120min,n(CuO):n(Na_2CO_3)为 1.1:1,CuO沉淀反应温度为 80℃,反应时间 30min,n(CuO):n(Na_2S)为1.45:1等条件下,再生后的NaOH含量可在8％以上,并且再生碱液的物性以及再生碱液对CO_2吸收速率上与新鲜碱基本相同。

A two-step method of causticization and precipitation technology was used to revive spent caustic of ethylene cracking, and various conditions which affect regeneration efficiency of the reaction were studied. When the causticization time was longer than 120min and higher than 80℃ with 1. 1: 1 of stoichiometric ratio,and the precipitation was longer than 30min at 80℃ with n(CuO): n(Na_2S) being 1. 45: 1, the NaOH concentration after reviving was denser than 8%, and the revived caus- tic approximately had the same physical property and adsorption of CO_2 as the new caustic.