Separation and concentration of succinic acid from post-fermentation broth by bipolar membrane electrodialysis (EDBM)

The separation and concentration of succinic acid from 3-component model solutions and actual post-fermentation broth after pre-treatment processes were studied in a 10-chamber large-scale EDBM setup. The influence of current density and initial concentration of succinates in the diluate chamber was evaluated by considering such factors as: (i) final succinic acid concentration, (ii) current efficiency and (iii) energy consumption for 1 kg of succinic acid production. According to the results, the highest acid concentration in the concentrate chamber and the highest current efficiency of 75.4% after 180 min of the process were obtained when the current density and the initial concentration of succinic acid salt in the diluate chamber were equal to 120 A/m2 and 200 g/L, respectively. The results have proved that it is possible to use the EDBM process as one of the steps of separation and concentration of succinic acid from the actual post-fermentation broth after biotechnological conversion of glycerol. Moreover, it should be stressed that the application of EDBM process allows the concentration of succinic acid and additionally the conversion from salts to the acidic form.