基于冷冻结晶法的乙烯废碱液“零排放”工艺与设计  

Process and design for“zero discharge”of spent caustic from ethylene cracking based on freezing crystallization method

作　　者：宋健健 SONG Jianjian(Sinopec Engineering Incorporation,Beijing 100101,China)

机构地区：[1]中国石化工程建设有限公司,北京100101

出　　处：《化工环保》2022年第6期779-784,共6页Environmental Protection of Chemical Industry

基　　金：中国石油化工股份有限公司技术开发课题(321141)。

摘　　要：为了实现乙烯废碱液的“零排放”,基于某石化厂乙烯废碱液湿式空气氧化出水具有的高硫酸根、高碳酸根、高有机污染物的特点及“零排放”的处理要求,开展了乙烯废碱液的“零排放”工艺路线比选,确定了以冷冻结晶工艺为核心的技术路线,并通过水质分析、溶解度和超溶解度曲线的测定确定了冷冻结晶的主要工艺参数,实现了乙烯废碱液的“零排放”与资源化利用。经预测,采用该工艺后可以使硫酸钠回收率达到93.3%,产品TOC含量不高于30 mg/kg。According to the characteristics of the effluent from wet oxidation of spent caustic from ethylene cracking,such as high sulfate,high carbonate and high organic pollutants,and the requirements of“zero discharge”treatment,the process routes of spent caustic from ethylene cracking were compared and selected to realize the“zero discharge”of spent caustic from ethylene cracking,and the technology route with freezing crystallization process as the core was determined.By water analysis and solubility and super-solubility curve determination,the main process parameters of freezing crystallization were conformed,and the“zero discharge”and resource utilization of spent caustic from ethylene cracking were realized.After implementing this process,it was predicted that the recovery of sodium sulfate would reach 93.3%,and TOC of the product would be lower than 30 mg/kg.

关 键 词：乙烯废碱液 零排放 冷冻结晶 溶解度 

分 类 号：X52[环境科学与工程—环境工程]