New utilization of the NIR technique: Control of an ion exchange resins system for the lactic acid recovery from fermentation broth

The on-line utilization of the NIR technique to control lactic acid fermentation has been presented and discussed previously. The metabolite recovery can be carried out by using an ion exchange system. Lactic acid is adsorbed on a strongly acidic anion exchange resin and eluted with ammonium carbonate. The resulting ammonium lactate flows through a strong cation exchange resin in the H+- form to obtain lactic acid. The optimization of the ion exchange processes can be achieved by utilizing the NIR technique on-line. For the anion exchange process the lactic acid, glucose as well as the ammonium lactate concentration during the elution step were measured with NIR. The results obtained are presented and discussed, emphasizing the possibility of applying the NIR control to ion exchange resins in general.