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US 2003/0144463 A1Published application
Method of producing aminium lactate salt as a feedstock for dilactic acid or dimer production
AssigneeEnergenetics International, Inc.
InventorsSammy Mayfield Pierce, Cecil T. Massie
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Abstract
Polylactic acid is produced from dimers of lactic acid in an energy saving manner by contacting a lactic acid source via an extraction membrane with an amine carrier solvent to extract lactic acid across the membrane. One or two membranes may be used. After extraction, the aminium lactate salt is crystallized, disassociated and purified.
Claims18
A method of producing polylactic acid from dilactic acids, comprising:
- contacting a lactic source acid solution via a membrane with an extracting carrier solvent which contains an aliphatic amine, to extract said lactic acid across said membrane into said extracting carrier solvent;
- contacting said extracting carrier solvent via a second membrane, with an organic alkaline heterocyclic amine solution to back-extract said lactic acid source to form aminium lactate salt in water solution;
- crystallizing said aminium lactate salt;
- dissociating said aminium lactate salt in the presence of a cyclization catalyst and forming dilactic acid dimers;
- and
- purifying said dilactic acid dimers.
3 more elements
A method of producing dilactic acid dimers for subsequent production of polylactic acid in single membrane process comprising:
- contacting a lactic acid solution across a membrane with an organic heterocyclic amine base to form aminium lactate salt in water solution on one side of the membrane;
- crystallizing the formed aminium lactate salt;
- dissociating said formed aminium lactate salt in the presence of a cyclization catalyst to form dilactic acid dimer;
- and
- purifying said dilactic acid or dimer to form polylactic acid polymer.
2 more elements
Dependencies are inferred from the claim text.