PROCESS FOR PRODUCTION AND PURIFICATION OF LACTIC ACID

摘要

A process for producing and purifying lactic acid comprises growing a lactate salt-producing microorganism on an inexpensive substrate containing carbohydrate, corn steep liquor and corn oil until most of the carbohydrate is converted to lactate. The fermentation broth is then electrodialyzed to recover and concentrate the lactate salt in an aqueous stream which is subjected to water-splitting electrodialysis to form base and a lactic acid product. The resulting lactic acid product is treated first with a strongly acidic ion exchanger in the acid form to remove any sodium or other cations and then treated with a weakly basic ion exchanger in the free base form to remove any sulfate ions or sulfuric acid and to obtain a highly purified lactic acid product.