ELECTRODIALYFIC EXTRACTION OF LACTIC ACID FROM FERMENTATION BROTH USING WOOD WASTES OF PAPER MILL

Abstract

Lactic acid has wide applications in various fields like in food industries, chemical industries, cosmetics, pharmaceutical industries. It is also used as a monomer of polylactic acid which is biodegradable in nature. There are several ways for the production of lactic acid and can be produced from many sources like food wastes, wheat bran and even from the wood wastes of the paper mill. This procedure has dual advantages i.e. lactic acid production along with the steam production with slight change in calorific value. As paper industries are big energy intensive units, so it would be more advantageous if we use the raw material of paper industry (which is wood), for production of energy as well for the production of industrially oriented useful product like lactic acid. Wood rejects are generally discarded after screening of wood chips in chipper section of paper industries, and are simply burnt for the production of steam to meet energy need of paper industry. But now wood can be used for lactic acid production along with the steam production. Nearly 0.84g and 0.3 lOg of lactic acid was produced from 5g MRS + 5g oven dried wood and lOg oven dried wood respectively at optimum temperature and optimum p1-I i.e. 28°C & 6. Lactic acid can be estimated by HPLC using Ultrasphere C18 column. Isocratic mobile phase of 0.005 M sulphuric acid is a good option. The how-rate was set at 0.5 mi/min with analysis time of 20 mm. Other acids such as citric acid, malic acid etc can also be detected present in fermentation broth along with lactic acid. Afier estimation, lactic acid can be extracted by using two stage clectro-dialysis which uses water splitting electro-dialysis (WSFD) with bipolar membrane with nearly efliciency of 45- 50%. About 291Kg & 106.33Kg of Lactic acid can be produced from 343 Kg of wood rejects. which come from approximately 2.86 tonuc of wood which is required for production of tonne of paper. Wood after production of lactic acid can also be used ftr steam production with slight difference in calorific value. So this, whole process will be very cost effective 14- process along with generation of industrially valuable product