pH neutralization while succinic acid adsorption onto anion-exchange resins.

Succinic acid is a useful chemical and its purification from fermentation broth by ion-exchange resins has widely drawn attention. In this study, pH neutralization in the process of adsorption of succinic acid from model solutions and fermentation broth by anion-exchange resin NERCB 04 has been tested. Adsorption capacity of NERCB 04 was about 0.41 g succinic acid/g resin at concentrations of succinic acid in the range of 10-50 g/L in packed column. In the process of succinic acid removal, pH of the system could also be neutralized. The neutralizing ability of the resin as a neutralizing agent has also been studied in the model cycle system and in the real fermentation cycle process. It was found that NERCB 04 showed stable adsorption capacity and pH neutralization ability after each regeneration. A certain amount of anion-exchange resin could neutralize the low pH values (pH 2-5) and maintain the system around pH 7.0. This means the anion-exchange resins have the function of neutralizing reagent in the process of adsorbing succinic acid.