(371c) Fumaric Acid Recovery From Fermentation Broth by Activated Carbon Adsorption Followed by Desorption and Crystallization with Acetone

Fumaric acid, a dicarboxylic acid extensively used as a food acidulant and in the manufacturing of synthetic resins, can be produced from glucose in aerobic fermentation by the filamentous fungus Rhizopus oryzae. For fumaric acid recovery, acidification at a high temperature is usually required because of the low solubility of fumaric acid. Then, fumaric acid crystals can be obtained by cooling. However, the produced crystals may contain various impurities and need re-crystallization. In order to enhance the purity of fumaric acid, adsorption with activated carbon was investigated as a more economical separation method. The results from model fermentation broth (15 g/L fumaric acid, 5 g/L glucose, 5 g/L malic acid) showed that activated carbon had a high selectivity and high adsorption capacity (~250 mg/g) for fumaric acid, which generally increased with increasing the fumaric acid concentration in the solution. Desorption of fumaric acid from the activated carbon was then studied using acetone, which can effectively strip fumaric acid from activated carbon. After removing acetone by evaporation at 50 ^oC, fumaric acid crystals were obtained with a near 100% purity. The furmaric acid recovery yield from this process was affected by the amount of acetone and temperature used in desorption. After optimization, over 95% fumaric acid was recovered from activated carbon. Both activated carbon and acetone can be recovered and reused in the adsorption process. This process is effective and economical for fumaric acid recovery and purification, and should have great potential in industrial production of fumaric acid.