环己烷氧化液中己二酸萃取与反萃取优化

The Optimization on Extraction and Stripping Process of Adipic Acid in the Oxidation of Cyclohexane

在环己烷空气氧化生产环己酮的工艺中,由于存在氧化过度问题,在氧化液中存在一部分以己二酸为主的酸性物质.为了降低后续工艺的能耗和负荷,在低过氧化物消耗的同时对氧化液中的己二酸进行了回收.采用了萃取和反萃取实验方法,对萃取和反萃取条件进行优化.首先进行单级萃取和反萃取实验,采用工艺水为萃取剂,环己烷为反萃取剂,对水油质量比、温度、萃取时间和辅助溶剂的影响进行了考察,得到了最佳的工艺条件.在此条件下,萃取中酸萃取率达到51.2%,过氧化物损失率13.4%;反萃取中过氧化物回收率10.6%,酸反萃取率6.5%.在最佳工艺条件下进行多级错流平衡萃取和反萃取实验,结果表明,当萃取级数为7时,酸萃取率为87.1%,过氧化物损失率19%;当反萃取级数为8时,过氧化物损失率12.2%,酸反萃取率8.5%.

In the production process of cyclohexane oxidated using air to pruoduct cyclohexanone, because the degree of oxidation is serious , there is porting of acidity substance which contain with much adipic acid. In order to reduce load and the energy consumption of the follow-up process, the adipie acid has been recy- cled from the oxide solution at the consumption of peroxide. We adopt extraction and stripping combined ex- perimental, and optimize the process conditions. Through the extraction and stripping experiments with wa- ter and cyclohexane as extractant to extract the oxided solution,the result showed that the extraction effi- ciency of adipic acid was 51.2~ primary and loss rate of CHHP was 13.4~. Moreover, we can stripping CHHP ,the loss rate of CHHP was 2.8~~ and the stripping efficiency of adipic acid was 6.5%. Under the optimum technological conditions, we conduct the cross current multi-stage extraction and stripping experi- ments,the results show that the extraction efficiency of adipic acid was 87.1% and loss rate of CHHP was 19% after seven-stage cross current extraction. The loss rate of CHHP was 1.2% and the stripping effi- ciency of adipic acid was 8.5% after eight-stage cross current stripping.