Abstract:

Cumene hydroperoxide (CHPPO) is a new green process for producing propylene oxide. However, how to remove impurities such as organic acids and Na⁺ from the cumene oxidation solution has always been a key issue in the CHPPO process. Addressing problems like high investment, large footprint, and poor mass transfer effects of existing alkali water washing tower units, a coupled impurity removal technology based on static mixing and coalescence separation was developed through pilot and semi-industrial trials. This research also studied the effect of various operational conditions on the separation performance of the coupled technology, achieving efficient impurity removal from cumene oxidation liquid. The results show that under conditions with a 1.5% NaOH solution concentration, alkali solution usage at 4%—5% of the oxidation liquid feed volume, pure water usage at 3%—5%, and self-circulation volume at 10%—15%, the processed oxidation liquid had a total acid content below 10 mg/L and Na⁺ content below 0.5 mg/L. Furthermore, the coupled impurity removal technology was industrially applied for the first time in a petrochemical setting, resulting in processed oxidation liquid with an organic acid content of 33 mg/L and Na⁺ content of 0.4 mg/L, meeting the technical requirements for pretreatment in the epoxidation section. This also led to a 5% reduction in alkali and water usage, significantly enhancing the green attributes of the facility. This technology offers a highly promising option for solving deep purification issues in oxidation liquids and advancing the development of the epichlorohydrin synthesis process.

Key words: CHPPO, CHP oxidation liquid, coalescence, mass transfer, separation, alkali and water washing

摘要：

异丙苯过氧化氢法（CHPPO）是生产环氧丙烷的绿色新工艺，然而如何从异丙苯氧化液中脱除有机酸和Na⁺等杂质一直是CHPPO工艺的关键问题。针对现有碱水洗单元洗涤塔设备投资高、占地面积大、传质效果不佳等问题，通过小试和中试实验，开发了基于静态混合和聚结分离的耦合除杂技术，并研究了一系列操作条件对耦合技术分离性能的影响，实现了异丙苯氧化液高效除杂。结果表明，在NaOH溶液浓度为1.5%，碱液用量为氧化液进料量的4%~5%、纯水用量3%~5%、自循环量10%~15%的条件下，处理后的氧化液总酸含量低于10 mg/L，Na⁺低于0.5 mg/L。此外，耦合除杂技术在某石化工业装置上实现了首次工业应用，处理后的氧化液有机酸含量为33 mg/L、Na⁺含量为0.4 mg/L，满足环氧化工段对前处理的技术要求，同时减少了5%的碱、水用量，显著增加了装置的绿色属性。该技术为解决氧化液深度净化问题和促进环氧丙烷合成工艺的发展提供了一种极具前景的选择。

关键词: 异丙苯过氧化氢法, CHP氧化液, 聚结, 传质, 分离, 碱水洗