Separation Processes in Biopolymer Production

Abstract

Recently lactic acid (LA) and its polymer, polylactic acid (PLA), have attracted the attention of world researchers due to their versatile commercial applications. Whether LA can be used to its full potential largely depends on whether it can be produced in a cost-effective manner with high purity and optical activity. The major technology barrier in the costeffective production of high-purity lactic acid is its downstream separation and purification. This chapter presents a case study where different techniques such as electrodialysis, adsorption, solvent extraction, membrane separation and reactive distillation were analyzed for separation of lactic acid from fermentation froth. Among them, reactive distillation was found to be promising at an industrial scale. Autocatalytic reactive distillation of lactic acid with methanol using a packed bed column followed by hydrolysis of methyl lactate with lactic acid catalyst, using three CSTRs in series, has been reported for purification of lactic acid.