Down Streaming of Lactic Acid from Hydrolysate of Barley after Fermentation

Different downstream processes were studied for the production of lactic acid after fermentation of glucose from hydrolysate of shredded barley. The fermentation broth successively passed through ultrafiltration, softening, conventional electrodialysis that operated in a two-level mode (water transport: 0.4 L/eq; current efficiency: 78%), electrodialysis with bipolar membranes (water transport: 0.17 L/eq; current efficiency: 73%), ion exchange, decolorisation, and finally evaporation. The product of the pilot plant was a concentrated lactic acid with a small portion of impurities and a concentration of up to 668 g/L. This process can be used to clean lactic acid for high grade applications in industry