Optimization of Precipitation Process for the Recovery of Lactic Acid

Abstract

Abstract:1)In this study, precipitation process was developed for the recovery of the lactic acid from calcium lactate fermentation broth. Calcium lactate yield was improved by decreasing the solubility of calcium lactate through the addition of ethanol (25%, v/v) as a co-precipitant. The optimal lime type, lime concentration, stirrer speed, precipitation time, temperature, and solvent amount for Ca(LA)2 precipitation were CaO, 0.0175 g/mL, 220 rpm, 24 h, 5℃, ethanol 25% (v/v), respectively. Lactic acid was easily and efficiently recovered from precipitated Ca(LA)2 by adding sulfuric acid (Ca(LA)2/ H2SO4 molar ratio=1：1). In the model solution of organic acids and fermentation broth, the overall yields of recovered lactic acid were 62% and 55%, respectively, under the aforementioned optimal conditions.