earticle

영어

Impurity removal is an important step in the downstream process for recovering bio-based 2,3-butanediol from fermentation broth cultured by Klebsiella oxytoca. We have studied a method to effectively remove salt components in the fermentation broth using alcohol precipitation, which mainly consists of vacuum evaporation and alcohol precipitation for concentration and impurities removal, respectively. This method is based on the simple salting-out mechanism by alcohol addition into aqueous solution. The recovery ratio of 2,3-butanediol through this separation method strongly depends on the filtration characteristics of the mixture of alcohol and concentrated broth, which contains precipitated solids. In this study the fermentation broths treated with microfiltration, ultrafiltration, and nanofiltration, respectively, were subjected to the rest of the alcohol precipitation procedure. The results showed that more uniform size of precipitated particle was obtained after alcohol precipitation as the pore size of the membrane filter got smaller. In addition, the recovery ratio of 2,3-butanediol also increased with the uniformity of the solid particles rejected by the membrane filter.