Process for the purification of 1,3-propanediol from a fermentation medium

The present invention relates to a process for the purification of 1,3-propanediol from a fermentation medium of a 1,3-propanediol-producing microorganism, comprising 1,3-propanediol and fermentation coproducts consisting at least of glycerol, wherein the 1,3-propanediol-producing microorganism is separated from the other components of the fermentation medium to give a clarified aqueous solution, clarified aqueous solution is passed over a cation exchange resin to give at least one fraction comprising purified 1,3-propanediol and at least one fraction comprising the fermentation coproducts, and the 1,3-propanediol is recovered.

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What is claimed is:

1. A process for the purification of 1,3-propanediol from a fermentation medium of a 1,3-propanediol-producing microorganism, the fermentation medium comprising the1,3-propanediol-producing microorganism, 1,3-propanediol and fermentation coproducts consisting at least of glycerol, wherein: a) the 1,3-propanediol-producing microorganism is separated from the other components of the fermentation medium to give aclarified aqueous solution; b) said clarified aqueous solution is passed over a cation exchange resin to give at least one fraction comprising purified 1,3-propanediol and at least one fraction comprising the fermentation coproducts, the cation in thecation exchange resin being selected from the group consisting of lanthanum, lead, iron, zinc and aluminum; and c) the 1,3-propandiol is recovered.

2. The process according to claim 1, wherein the clarified aqueous solution of step a) is passed through a column of charcoal and demineralized on a strong cationic resin and then on a weakly and/or strongly basic anionic resin.

3. The process according to claim 1, wherein the clarified aqueous solution of step a) is treated with a microorganism which converts the glycerol to 1,3-propanediol.

4. The process according to claim 1, wherein the chromatographic fraction of step b) comprising the fermentation coproducts, are treated with a microorganism which converts the glycerol in the fermentation coproducts to 1,3-propanediol.

5. The process according to claim 4, wherein the said fractions are reintroduced upstream of the chromatographic separation step.

6. The process according to claim 4, wherein the microorganism which converts the glycerol to 1,3-propanediol is selected from the group consisting of microorganisms of the genera Klebsiella, Citrobacter, Clostridium, Lactobacillus, Ilyobacter,Pelobacter and Enterobacter.

7. The process according to claim 6, wherein the microorganism is a Citrobacter or a Clostridium.

8. The process according to claim 4, wherein the microorganism which converts the glycerol to 1,3-propanediol is present in the fermentation medium in a free or an immobilized form.

9. The process of claim 8, wherein the microorganism is present in the immobilized form.