Recent advances in the separation and purification of lactic acid from fermentation broth

Abstract

Lactic acid (LA) is an important raw material, and can be used as a monomer in the production of biodegradable polymer - polylactic acid, which has received extensive attention in recent years. Currently, most LA is produced by biological fermentation, and its downstream separation process is crucial in terms of production cost and high product purity. It is vital to select a proper separation technique for lactic acid production. This paper reviews the recent advances in the separation and purification of lactic acid from fermentation broth, including the separation technologies based on phase transition (including traditional precipitation method, solvent extraction, adsorption and molecular distillation), membrane separation and esterification. Based on the literature and previous studies of our group, the principles, advantages, limitations, and future prospects of these technologies are discussed. Among them, the integration process of multiple technologies and the coupling process of separation and fermentation will be the future research direction. We hope this article can provide references and ideas for the development of more efficient and advanced LA separation technology.