废碱液综合处理工艺

COMPREHENSIVE TREATMENT PROCESS FOR SPENT CAUSTIC

对以渣油为原料生产乙烯CPP工艺产生的废碱液,采用乙烯常规缓和湿式氧化工艺,不仅生产运行费用高,而且CPP废碱液中还包含裂解汽油的废碱液,成份较乙烯废碱液复杂。借鉴企业原有DCC装置废碱液处理的经验,经过专利商的改进,开发出废碱液综合处理工艺。介绍了废碱液综合处理的工艺原理,主要运行操作温度,pH值控制,综合营养液加入比例。通过水质分析看出,该装置来水COD平均约17 000 mg/L,略低于设计值;硫化物平均为5 230 mg/L,高于设计值,处理后出水COD全部小于60 mg/L,氨氮、硫化物、酚含量、含油、悬浮物等各项指标全部达标。

Aiming at the spent caustic generated from CPP which is a process to produce ethylene with residual oil as raw material,moderate wet air oxidation process is adopted in ethylene production in a conventional way. The operation cost is high and CPP spent caustic contains spent caustic from cracking gasoline which has more complex components than that from ethylene spent caustic. Based on the previous treatment experience in DCC's spent caustic and through the licenser's improvements,a comprehensive treatment process for spent caustic is developed. This paper introduces the process principles,major operating temperature,pH value control and adding proportion of the comprehensive nutrient solution of comprehensive treatment process for spent caustic. Through water quality analysis,it can be seen that the average COD of the incoming water in the unit is about 17 000 mg / l which is a bit lower than the design value; and the average sulfide is about 5 230 mg / l which is higher than the design value. After the treatment,COD of the effluent is lower than 60 mg / l and all indexes such as ammonia nitrogen,sulfide,phenol content, oil content and suspended matter reach the standards.