BACKGROUNDPyruvic acid and its salts, key chemicals in the bio-refinery sector, are normally purified in the liquid form mainly through reactive extractions or chromatographic methods. For the isolation of sodium pyruvate, current work explores a repulsive extraction and crystallization method using polar aprotic solvents. RESULTSBecause of the high affinity of polar components present in fermented broth towards water and also due to favorable interaction of sodium pyruvate with added solvent, sodium pyruvate allows repulsive extraction from the fermented broth solution. Acetone causes maximum repulsion of sodium pyruvate with reduction of 80% solubility from the fermented solution. Increase in concentration of sodium pyruvate and other components present in fermented broth are responsible for the enhanced extraction of sodium pyruvate in acetone. Initial concentration of 20% by weight resulted in 79% yield of the desired purity sodium pyruvate by repulsive extraction. The whole process involving micro-filtration, vacuum evaporation, followed by repulsive extraction and crystallization yielded 97% pyruvate purity with overall 75% yield. The lab scale process was scaled by a factor 62, resulting in 900 gm of desired purity pyruvate. CONCLUSIONIn addition to providing high yield, the suggested process can also reduce the numerous purification steps and purification time for large-scale production of sodium pyruvate or pyruvic acid. (c) 2014 Society of Chemical Industry