Alpha-ketoglutaric acid production using electrodialysis with bipolar membrane

Environmentally friendly process of production of alpha-ketoglutaric acid (AKG) from model water solutions by bipolar membrane electrodialysis (EDBM) was carried out. Two-chamber EDBM stack with the anion exchange membrane-bipolar membrane (AM-BM) configuration was used to transport AKG ions through AM from the diluate to concentrate chamber and convert them to AKG acidic form. The influence of initial pH of diluate solution, initial concentration of AKG salts in the diluate and concentrate chambers and current efficiency was evaluated by considering such factors as voltage drop, alpha-ketoglutaric acid concentration, current efficiency and energy consumption for 1 kg of AKG production. Under optimum conditions the process EDBM allows achievement of a high concentration of AKG, high current efficiency and low energy consumption, equal to 4.83 g/L, 71.8%, 3.72 kW h/kg, respectively, while the corresponding results obtained after 180 min EDBM process without optimization were 1.6 g/L, 24% and 15.26 kW h/kg, respectively. In addition, the obtained results indicate that bipolar membrane electrodialysis may be used for the production of AKG from actual post fermentation broth in the future.