Lactic acid and its separation and purification techniques: A review

In this current review article, a significant number of published articles were reviewed in order to provide comprehensive literature information about lactic acid (LA) and its various separation techniques. A rapid growth in the requirement of biodegradable polymers (such as polylactic acid) which are frequently used as an alternative for both manufacturing of conventional based plastic commodity materials and new materials of pertinent applications are continuously drawing ample amount of attention for the replacement of previously existing various LA separation techniques. Significant advancements are also progressively going on in the commercial applications (food as well as non-food industries) of LA. Till date, most of the LA producers use only the conventional method i.e. precipitation method which is costly and environmentally un-favourable. At present, emulsion liquid membrane (ELM) based separation technique is known as one of the most attractive and prominent technique of LA extraction from aqueous solution along with the higher extraction efficiency, low energy and chemical consumption, simplicity, and competitiveness than the other existing techniques. ELM-assisted extraction technique is one of the rapid developing technology in the area of separation and purification technology. This current literature survey will be very useful in the view of detail study of LA (its methods (chemical as well as fermentation) of production, current & commercial applications, and pertinent properties) and in the selection of its appropriate separation technique. In this review, a promising technique in the separation process called ELM along with its current advances is proposed for LA separation from the dilute aqueous solutions of the various fermentation-based industries.