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US 6,187,951 B1Granted
Lactic acid production, separation and/or recovery process
AssigneeCargill, Incorporated
InventorsAvraham M. Baniel, Aharon M. Eyal, Joseph Mizrahi, Betty Hazan, Rod R. Fisher
Life of this patent
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Abstract
A process for the production and isolation of lactic acid is provided. A lactate feed solution, preferably obtained from a fermentation broth is combined with and extracted by a water-immiscible base in the presence of an acidifying agent. Lactic acid is recovered from the resulting organic phase. Recovered carbonate or bicarbonate from the aqueous phase can be recycled to the fermentor and regenerated extractant can be recycled for use in the extraction.
Claims23
A process for the recovery of lactic acid;
- said process including the steps of:
- (a) forming a multi-phase system including at least a first aqueous phase and a second, water-immiscible, liquid phase;
- (i) said first aqueous phase having a pH of 4 to 14 and including lactate salt in solution;
- (ii) said second water-immiscible phase including an extractant capable of forming a water-immiscible lactate salt, with a lactate-containing component;
- (b) extracting said first aqueous phase with said second water-immiscible phase by extracting the lactate-containing component by forming a water-immiscible lactate salt with the extractant;
- (i) said step of extracting including a step of acidifying at least one of said first aqueous phase and said second water-immiscible phase, by addition of acid thereto, without providing said first aqueous phase with a pH below 4;
- (c) separating a resulting water-immiscible phase from a resulting aqueous phase after said step of extracting;
- and
- (d) generating lactic acid from the lactate salt of the extractant, wherein said step of generating lactic acid comprises at least one of:
- (i) back-extracting the water-immiscible phase, resulting from said step of separating, with water;
- and
- (ii) vaporizing at least a portion of the water-immiscible phase, resulting from said step of separating.
9 more elements
A process for recovery of lactic acid;
- said process including the steps of:
- (a) forming a multi-phase system including a first aqueous phase and a second water-immiscible phase;
- (i) said first aqueous phase including lactate salt in solution;
- (ii) said second water-immiscible phase including lactic acid extractant;
- (b) extracting said first aqueous phase with said water-immiscible phase;
- (i) said step of extracting including a step of acidifying at least one of said first aqueous phase by addition of an acid thereto, and said water-immiscible phase under conditions wherein, at any given point, at least 50% of lactate-containing component in the aqueous phase remains in the lactate salt form;
- and
- (ii) said step of extracting comprises removing at least 90% of lactate-containing component, as lactic acid, from said first aqueous phase and into said water-immiscible phase;
- (c) separating a resulting water-immiscible phase from a resulting aqueous phase after said step of extracting;
- and
- (d) generating lactic acid from the lactate salt of the extractant, wherein said step of generating lactic acid comprises at least one of:
- (i) back-extracting the water-immiscible phase, resulting from said step of separating, with water;
- and
- (ii) vaporizing at least a portion of the water-immiscible phase, resulting from said step of separating.
11 more elements
Dependencies are inferred from the claim text.