A CLEANING PROCESS OF PRODUCING LACTIC ACID

摘要

Provided is a cleaning process of producing lactic acid. Firstly saccharification liquid is prepared through saccharated materials, then fermented with nutritive materials and lactic acid bacteria, liquid alkali is used to adjust the pH. The fermentation broth is filtrated with porous membrane, and the lactic acid bacteria in the interception liquid is then reintroduced in the fermentation unit for recycling. The permeate from porous membrane is subjected to nanofiltration to be decoloured and purified. The concentrated solution from nanofiltration and the cleaning liquid from fermentation tank and its affiliated equipments are filtrated and sterilized by using ceramic membrane, and then are reintroduced in the fermentation unit for recycling. The permeate from nanofiltration is then subjected to bipolar electrodialysis system to prepare lactic acid, and the liquid alkali produced at the same time is reintroduced in the fermentation tank for recycling. The lactic acid is finally concentrated by using vacuum distillation.