A novel process for recovery and refining of L-lactic acid from fermentation broth

This paper introduces a novel process for recovery and refining of L-lactic acid from a fermentation broth. The use of a solvent extraction step, in the novel approach, has significant impacts on the following centrifugal short-path distillation conditions (operating pressure, evaporator temperature and feed flow rate). As the conditions were varied, the l-lactic acid purity and yield in the distillate were monitored. For the purpose of comparison, a series of experiments were also carried out using the existing purification process. The results showed that both of the two processes can obtain l-lactic acid with a high purity around 91.3%, while the yield obtained using the novel process reached 61.73%, which was about 20.43% higher than that using the existing process. Additionally, multiple-pass distillation observed special attention by improving the yield up to 74.63%.