Recovery of succinic acid from fermentation broth by forward osmosis-assisted crystallization process

In this study, osmotically driven forward osmosis (FO) was employed prior to crystallization process in the downstream recovery of bio-based succinic acid. The fermentation broth containing succinic acid was initially pretreated using activated carbon. Powdered activated carbon (PAC) showed its effectiveness for glucose, formic acid, and color removal while succinic acid concentration remained unaffected. The untreated and treated fermentation broths were then concentrated using the FO process. FO exhibited a remarkable enhancement of concentration factor (CF) by 3.9-fold for the treated broth, thus resulting in a final succinic acid concentration of 111.26 g/L. By contrast, higher flux loss and lower CF were observed for untreated broth, mainly due to the adverse effect of severe membrane fouling and cake layer formation. Succinic acid crystals were then successfully recovered from the FO-concentrated broth in the final crystallization step. The purity and yield of succinic acid crystals were 90.52% and 67.09%, respectively for treated broth. This work demonstrated the development of a feasible FO-crystallization process for the downstream recovery of bio-based succinic acid. The findings have important implications for practical applications of FO technology in the bioprocess industries.