文献类型：期刊文献

英文题名：Experimental investigation of red oil removal from ethylene spent caustic via extraction and coalescence techniques

作者：Jie, Hongkai[1];Li, Lin[1];Lu, Guofu[1];Liu, Jinze[1];Chen, Kelong[1];Yang, Qiang[1];Lu, Hao[1]

机构：[1]East China Univ Sci & Technol, Shanghai 200237, Peoples R China

年份：2026

卷号：380

外文期刊名：SEPARATION AND PURIFICATION TECHNOLOGY

收录：;EI(收录号：20253819193064);WOS:【SCI-EXPANDED(收录号:WOS:001576926400001)】；

基金：This study was supported by the National Natural Science Foundation of China (Grant No. 52370077).

语种：英文

外文关键词：Alkali salt; Red oil removal; Spent caustic; Oil-water separation; Extraction-coalescence

摘要：The concentration of alkali in the caustic tower plays a critical role influencing the efficiency of caustic washing and alkali consumption. While online instrumental analysis is a key method for monitoring alkaline salt concentration, the precipitation of red oil, which blocks the sampling pathway, presents a significant challenge to accurate detection. To address this issue, this study introduces a novel method that combines extraction and coalescence principles. It utilizes cracked gasoline-a byproduct of ethylene production-as an extractant combined with physical demulsification techniques, to effectively eliminate red oil from spent caustic. The results of the pilot test in an ethylene plant demonstrate that this method can effectively stabilize the oil content of the effluent between 40 and 60 mg/L. Furthermore, it minimizes the loss of alkaline salts concentration to within 5 % and shortens the oil-water separation time to 15 min. This method offers a reliable pretreatment solution for online detection of alkaline salts, enabling timely and accurate performance of analyzers and ensuring dependable monitoring of alkaline salt concentrations.