The extraction of lactic acid with sulfur dioxide

This paper studies the reaction between SO2 and calcium lactate, which potentially can be used to recover lactic acid from the anaerobic fermentation broth of an SO2 waste stream. The conversion of given amounts of calcium lactate to lactic acid was evaluated under different reaction temperatures and flow rates of SO2. Analyses of concentrations of the produced lactic acid indicated that the reactions between SO2 and calcium lactate were complete under all experimental conditions.