Method for recovering succinic acid crystals using surfactants during crystallisation, and resulting crystals
AssigneeRoquette Freres
InventorsPierrick Duflot, Pierre Lanos, Baptiste Boit, Frédérick Dehay, Laurent Rossi
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Abstract
The invention relates to a method for producing succinic acid crystals, comprising double crystallisation and the use of at least one surfactant during the first crystallisation step. The invention also relates to the succinic acid crystals obtained from a fermentation medium, characterised in that they have a colour index b, measured in the reference system L, a, b, that is less than or equal to 1.00, preferably less than or equal to 0.90, and, better still, less than or equal to 0.80.
Claims17
A process for producing succinic acid crystals from a fermentation medium containing succinic acid, comprising:
- a) bringing a fermentation medium to a pH of between 1.0 and 4.0,
- b) crystallizing succinic acid from the fermentation medium resulting from step to form first succinic acid crystals and a first crystallization mother liquor, then separating the first succinic acid crystals from the first crystallization mother liquors and then washing the obtained crystals with water to obtain washed succinic acid crystals,
- c) dissolving the washed succinic acid crystals in water at a temperature between 30° C. and 70° C. to obtain a solution containing dissolved succinic acid,
- d) purifying the solution by contacting said solution with activated carbon and on ion exchange resin,
- e) crystallizing succinic acid contained in the purified solution to form second succinic acid crystals, and a second crystallization mother liquor, separating the second succinic acid crystals from the second crystallization mother liquors and then washing the second succinic acid crystals with water,
- f) drying the washed, second succinic acid crystals of step e) to a moisture content of less than 0.5% and cooling them to a temperature below 30° C., wherein at least one surfactant is introduced before and/or during step b).
Fermentation produced succinic acid crystals comprising a color index b, measured in the reference system L, a, b, of less than or equal to 1.00.
Fermentatively produced succinic acid crystals having a moisture content of less than 0.5% by weight, a sphericity of greater than 0.70, and a color index b, measured in the reference system L, a, b, of less than or equal to 1.00.
Dependencies are inferred from the claim text.