Recovery of citric acid from impure process streams by addition of strong acids and salts thereof.

摘要

This invention provides an improved process of recovering citric acid from an impure process stream such as fermentation broth by the addition of a strong acid or salts thereof to a concentrated solution of the citric acid. The process provides for essentially one step purification without the waste disposal problems or large capital investment required by either lime sulfuric or solvent extraction recovery processes. The recovery may be further improved by treating the mother liquor remaining after separation of the citric acid crystals to obtain an additional yield. The preferred strong acid is sulfuric acid and the preferred mother liquor treatment is an ion exclusion resin column. While the improved process is particularly advantageous when used as a one-step purification process for citric acid directly from fermentation broth, it may also be used in conjunction with the various impure process streams generated by the lime sulfuric or solvent extraction recovery processes.