二氯丙醇制备环氧氯丙烷的管式反应-薄膜蒸发耦合工艺

Tubular reaction-thin film evaporation coupling process for producing epichlorohydrin from dichloropropanol

摘要:

环氧氯丙烷是一种重要的有机化工原料和生产环氧树脂的聚合单体，工业生产中由二氯丙醇经塔式皂化环合反应工艺制得。为快速高效分离环氧氯丙烷，降低能耗，减少废水排放，设计了管式反应器与薄膜蒸发耦合制备环氧氯丙烷的工艺路线，研究了反应物摩尔配比、NaOH溶液浓度、反应温度、管道反应停留时间、薄膜蒸发温度和薄膜蒸发压力对环氧氯丙烷收率的影响。结果表明，当物料摩尔配比为1.05:1、NaOH溶液浓度为20%(wt.)、反应温度为50℃、管式反应停留时间为15s、薄膜蒸发温度为50℃、薄膜蒸发压力为100mbar时，环氧氯丙烷的收率达到97.3%。薄膜蒸发与管式反应的工艺耦合，降低了原料消耗，缩短了反应时间，产物收率较高；与管式反应-精馏耦合工艺相比，操作弹性较大，产物收率较高，能耗较低，产生废水量较少。

Abstract:

As an important organic chemical material and monomer for producing epoxy resin, epichlorohydrin is industrially derived from the saponification cyclization of dichloropropanol in a tower reacting system. In order to separate product away speedy and effectively to depress energy consumption and wastewater discharge amount, tubular reactor coupling with thin film evaporation was designed as a new process for producing epichlorohydrin. The influence of different technical factors of the coupling process including reactants’ molar ratio, NaOH solution concentration, reaction temperature, tubular residence time, thin film evaporation temperature and thin film evaporation pressure on yield were investigated. It turned out that at conditions when n(NaOH): n(DCP) = 1.05:1, NaOH solution concentration at 20%(wt.), reaction temperature at 50℃, tubular residence time at 15s, thin film evaporation temperature at 50℃, thin film evaporation pressure at 100mbar, the yield of epichlorohydyin reached 97.3%. The coupling process of tubular reaction and thin film evaporation was improved in its lower material consumption, shorter reacting time and higher product yield. Comparing with tubular reactor - rectification coupling process, this process was superior for its better operation flexibility, higher product yield, lower energy consumption and lesser wastewater discharge.