Patent ID: 7217349

Claim:
A method of separating multivalent ions and lactate ions from a fermentation broth comprising a multivalent ion lactate salt by using an electrodialysis or electrolysis apparatus, the method comprising: introducing the broth into a first compartment, said broth having a multivalent ion concentration of at least 0.1 mole/l, said broth having a lactate ion concentration of less than 300 g/l, said broth including negatively charged ion that is not lactate ion in an amount of less than 10 mole % based on a total amount of lactate ion in said broth, and said first compartment being limited by an anion-selective or non-selective membrane and a cathode; converting the multivalent ion to obtain a residual stream comprising a hydroxide of the multivalent ion; transporting the lactate ion through the anion-selective or non-selective membrane into a second compartment, said second compartment being limited by the anion-selective or non-selective membrane and an anode; and neutralizing the lactate ion to lactic acid; wherein the multivalent ion is a multivalent metal ion selected from the group consisting of magnesium, calcium, zinc, iron, aluminum, and mixtures thereof.