加电解质分离2-甲基吡嗪-水混合物

提出“精馏-加电解质萃取”联合过程分离2-甲基吡嗪(MP)-水混合物,其中加电解质萃取是工艺的关键。MP-水混合物加电解质萃取过程的最佳工艺条件为:选用质量分数为60％的NaOH水溶液作萃取剂,萃取温度30～40℃,萃取比m(NaOH水溶液)/m(MP-水混合物)=0.5/1。NaOH对MP-水共沸物脱水率达95.5％,萃取后有机相中ω(MP)=96.1124％;并研究了NaOH水溶液作为萃取剂的稳定性。实验表明,NaOH水溶液性能稳定,易回收,可循环使用。

Study on Salt - Effect Separation of Aqueous 2 - Methylpyrazine Mixture

A novel combined process of salt extraction with distillation for separation of 2 - methylpyrazine -water mixture was developed, in which salt extraction was the key process. Effective salt was selected. Effects of NaOH on liquid - liquid equilibrium of 2 - methylpyrazine - water system were studied. Optimum conditions of salt extraction were investigated: ω (NaOH) = 60 % , temperature 30 - 40 ℃ , and extraction ratio m (NaOH aqueous solution) /m (2- methylpyrazine - water mixture) = 0.5/1. Under such conditions, concentration of 2 -methylpyrazine in extract phase could reach 96. 11%, and dehydration ratio of 2 - methylpyrazine - water azeotropic mixture was 95. 5% . Stability of NaOH aqueous solution in cycling was investigated. Recovery of NaOH solution was easy. Effectiveness of recovered NaOH aqueous solution was comparable with fresh solution.