盐析-萃取工艺分离2-甲基咪唑母液的研究

Study of separation of 2-methylimidazole from 2-methylimidazole mother liquor by salting-out extraction

研究了2-甲基咪唑母液的盐析-萃取法分离工艺。考察了NaOH、NaCl的浓度、萃取温度3个因素对2-甲基咪唑萃取率的影响,通过单因素实验和正交实验确定最佳分离条件为:NaOH浓度为2.5mol.L-1(NaOH的摩尔数:母液浓缩后体积,下同),NaCl浓度为2.6mol.L-1,萃取温度为70℃,此时,萃取率为83.74%。盐析-萃取法分离2-甲基咪唑母液具有工艺简单、回收率高、成本低等特点,是适用于工业化生产的一种能有效分离2-甲基咪唑母液的方法。

The technology of the separation of 2-methylimidazole from 2-methylimidazole mother liquor by salting-out extraction was investigated.The effects of NaOH and NaCl concentration,the temperature on the extraction rate of 2-methylimidazole were studied.Through single factor experiment and orthogonal experiment,the optimum separation conditions were determined as follows： the NaOH concentration was 2.5mol·L-1（the mol of NaOH：the volume of concentrated mother liquor）,the NaCl concentration was 2.6mol·L-1 and the extraction temperature was 70℃.Under above conditions,the rate of extraction was 83.74%.The salting-out extraction can separate 2-methylimidazole from 2-methylimidazole mother liquor in higher extraction rate with simple process and less cost.It is a effective way to separate 2-methylimidazole mother liquor in industrialized production.