Process for the recovery of lactic acid from aqueous lactate salt solutions, involving the use of ion exchangers

摘要

The invention provides a process for the recovery of lactic acid from aqueous solutions containing at least one water-soluble lactate salt and having a pH of about between 4 and 14, comprising the steps of: contacting said aqueous solution with a cation exchanger which is at least partially in its acid form, said cation exchanger being water immiscible in both acid and salt form, whereby ion exchange is effected, protons are transferred from the cation exchanger to the aqueous solution to acidulate it and to form lactic acid therein and cations from the aqueous solution are bound by the cation exchanger; reacting the cations carrying cation exchanger to convert it into a cation exchanger which is at least partially in its acid form and to a second product, which second product is basic and comprises the cation of the salt; and recovering lactic acid from the lactic acid-containing acidulated aqueous solution by methods known per se.