Solid-solid separation process for long chain dicarboxylic acids
AssigneesCathay Biotech Inc., Cibt America Inc.
InventorsBingbing Qin, Yufeng Yang, Xiucai Liu
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Abstract
The present disclosure provides methods for isolating a long chain dicarboxylic acid such as a substantially pure or pure long chain dicarboxylic acid from a fermentation broth containing microbial cells.
Claims58
A method for isolating a long chain dicarboxylic acid from a fermentation broth containing microbial cells, wherein the long chain dicarboxylic acid is a saturated or unsaturated straight chain dicarboxylic acid having 9 to 18 carbon atoms, with a carboxyl group at two ends of the chain, the method comprising:
- (a) adding an acid to the fermentation broth to produce a demulsified fermentation broth having a pH of 2-5 or 2.5-4;
- (b) centrifuging the demulsified fermentation broth using a hydraulic cyclone centrifuge, a hydrocyclone centrifuge, a horizontal spiral centrifuge, or any combination thereof to generate a first phase comprising the long chain dicarboxylic acid and a second phase comprising the microbial cells;
- and
- (c) isolating the long chain dicarboxylic acid from the first phase by filtration to recover an isolated long chain dicarboxylic acid product,
- wherein the total concentration of dicarboxylic acids in the fermentation broth is at least 85% by dry weight, and
- wherein the isolated long chain dicarboxylic acid has a purity of at least 95% or higher, or at least 97% or higher.
A method for isolating a long chain dicarboxylic acid from a fermentation broth containing microbial cells, wherein the long chain dicarboxylic acid is a saturated or unsaturated straight chain dicarboxylic acid having 9 to 18 carbon atoms, with a carboxyl group at two ends of the chain, the method comprising:
- (a) adding sulfuric acid to the fermentation broth to produce a demulsified fermentation broth having a pH of 2.5-4;
- (b) heating the demulsified fermentation broth to a temperature from 90° C. to 105° C.;
- (c) centrifuging the demulsified fermentation broth using a hydraulic cyclone centrifuge, a hydrocyclone centrifuge, a horizontal spiral centrifuge, or any combination thereof to generate a first phase comprising the long chain dicarboxylic acid and a second phase comprising the microbial cells, wherein the first phase is substantially free of the microbial cells and the second phase is substantially free of the long chain dicarboxylic acid;
- and
- (d) isolating the long chain dicarboxylic acid from the first phase by filtration to recover an isolated long chain dicarboxylic acid.
Dependencies are inferred from the claim text.