微混合器连续盐析萃取2,3-丁二醇的研究

Continuous salting-out extraction of 2,3-butanediol using a microchannel mixer

盐析萃取是-种高效分离发酵液中亲水性小分子产物的方法，目前的研究以间歇操作为主．本文设计组装了-个由微通道混合器和静置器组成的连续盐析萃取系统并考察了混合时间对分相和2,3-丁二醇分配的影响．以24％乙醇-25％磷酸氢二钾（w／w）组成的盐析萃取体系在连续混合条件下进行盐析萃取实验，结果表明，在混合时间为9-60s时，混合时间对2，3-丁二醇的回收率影响不大、对相比有-定影响；混合时间为20．7S，静置8h时相比最小，2,3-丁二醇的回收率达96％以上；混合时间为20．7s，静置25min时，连续盐析萃取时上相2,3-丁二醇浓度为78g／L，下相为5．63g／L，分配系数为13．85，回收率为96．2％，连续运行过程中得到的上、下相浓度和密度较稳定，证实了连续盐析萃取2，3-丁二醇的可行性．

Salting-out extraction is an efficient method to separate the hydrophilic molecules with low-molecular weight from fermentation broth, and its process is discontinuous at present. In this study a continuous salting-out extraction system is constructed which is composed of a micro-channel mixer and a stationer, and the effect of mixing time on phase formation and 2,3-butanediol partition behavior was explored. The experiments was carried out with a salting-out system formed by 24% ethanol （w/w） and 25% K2HPO4 （w/w）, and the results showed that mixing time has no obvious effect on the recovery of 2,3-butanediol, but affects the phase ratio obviously in the mixing time of 9 to 60 s. The least phase ratio was obtained at the mixing time of 20.7 s, and the recovery was above 96% after the 8 h standing under continuous mixing condition. When the retention time in micro-channel mixer and stationer was 20.7 s and 25 min, respectively, the concentration of 2,3-butanediol was 78 g/L in upper phase and 5.63 g/L in the bottom which has little fluctuation during the process, and the partition coefficient and recovery was 13.85 and 96.2%, respectively. The results verified the feasibility of continuous salting-out extraction of 2,3-butanediol.