Method and apparatus for concentration and crystallization of fermentable carboxylic acids

Patent metadata

Field	Value
Publication number	US-9988335-B2
Application number	US-201515326139-A
Country	US
Kind code	B2
Filing date	Jul 3, 2015
Priority date	Jul 14, 2014
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A method for concentrating and crystallizing fermentable carboxylic acids, salts, and mixtures thereof may involve the use of carboxylic acids that have a defined temperature dependence of the solubility and of the osmotic pressure. The carboxylic acids may be concentrated by a membrane method and subsequently crystallized out by a cooling crystallization and isolated. In some examples, the membrane method may involve nanofiltration, reverse osmosis, and/or membrane distillation for separation into a concentrate and a permeate. Similarly, an apparatus for implementing such methods may include a nanofiltration, reverse osmosis, and/or membrane distillation unit for concentrating the carboxylic acid, and at least one cooling crystallization unit for crystallizing the carboxylic acid.

First claim

What is claimed is:

1. A method for concentrating and crystallizing fermentable carboxylic acids, salts, and mixtures thereof, the method comprising:
providing a processed fermentation broth or an aqueous solution of a carboxylic acid,
wherein the carboxylic acid has a molar mass in a range from 90 to 210 g/mol,
wherein the carboxylic acid has a solubility in water at 20° C. of 4 g/l to 100 g/l,
wherein the carboxylic acid has a relative increase in solubility in a temperature range from 20 to 80° C. of at least 2%/° C. relative to the solubility at 20° C., and
wherein a concentrated solution of the carboxylic acid has an osmotic pressure in a temperature range from 20 to 80° C. of less than 80 bar;

concentrating the carboxylic acid in the processed fermentation broth or the aqueous solution by way of a membrane method, wherein the carboxylic acid is concentrated in the processed fermentation broth or the aqueous solution by a factor of 1 to 5 up to immediately before attainment of a solubility limit of the carboxylic acid;
subjecting the concentrated processed fermentation broth or the aqueous solution of the carboxylic acid to a cooling crystallization; and
isolating crystals of the carboxylic acid.

2. The method of claim 1 comprising concentrating the carboxylic acid in the processed fermentation broth or the aqueous solution such that a concentration of the carboxylic acid in the processed fermentation broth or the aqueous solution increases from 1 to 10% by weight to 12 to 25% by weight.

3. The method of claim 1 comprising concentrating the carboxylic acid in the processed fermentation broth or the aqueous solution to a degree such that supersaturation of the processed fermentation broth or the aqueous solution and therewith incipient crystallization occur on cooling to 10 to 40° C.

4. The method of claim 1 wherein the membrane method comprises at least one of nanofiltration, reverse osmosis, or membrane distillation for separation into a concentrate and a permeate, wherein the nanofiltration, the reverse osmosis, and the membrane distillation can be performed in one-stage form, in two-stage form, in multistage form, or in combination with one another.

5. The method of claim 4 comprising performing the reverse osmosis in two-stage form, with a permeate of a first reverse osmosis stage being supplied to a second reverse osmosis stage, with a permeate of the second reverse osmosis stage being used to prepare a nutrient solution for fermentation.

6. The method of claim 1 wherein the concentrating occurs by way of membrane distillation and a distillate of the membrane distillation is used as an eluent for a subsequent chromatographic purification step, wherein the membrane distillation is performed at temperatures below a solubility limit of the carboxylic acid.

7. The method of claim 1 further comprising subjecting a concentrate from the membrane method to regenerative heat exchange in a heat exchanger, wherein the regenerative heat exchange occurs with a mother liquor drawn off from the cooling crystallization, wherein the concentrate is cooled to a temperature of 30 to 40° C. and then supplied to the cooling crystallization.

8. The method of claim 7 further comprising returning the mother liquor heated in the heat exchanger to the processed fermentation broth or the aqueous solution, wherein the mother liquor is purified by at least one of nanofiltration or ion exchange before being returned to the processed fermentation broth or the aqueous solution.

9. The method of claim 7 wherein in the cooling crystallization, the crystals are precipitated in the mother liquor, wherein the mother liquor that is separated from the crystals is returned for further use in the method.

10. The method of claim 9 wherein the cooling crystallization is carried out in two-stage form, with a first stage of the cooling crystallization comprising cooling with the mother liquor drawn off from a cooling crystallizer, with a second stage of the cooling crystallization comprising cooling with externally supplied cooling water or cooling brine.

11. The method of claim 1 wherein the cooling crystallization is performed in a contact crystallizer.

12. The method of claim 1 wherein steps for processing the fermentation broth comprise:
removing biomass from the fermentation broth by a first step of at least one of centrifugation, separation, precoat filtration, or microfiltration and a second step of ultrafiltration;
acidifying the fermentation broth with sulfuric acid, which results in a solution; and
performing SMB chromatography with the solution.

13. The method of claim 1 wherein the carboxylic acid has at least one of a molar mass of 110 g/mol to 150 g/mol or a solubility in water at 20° C. of 15 g/l to 90 g/l.

14. The method of claim 1 wherein the carboxylic acid is selected from a group consisting of fumaric acid, succinic acid, adipic acid, itaconic acid, threonine, methionine, aspartic acid, glutaric acid, asparagine, glutamine, histidine, isoleucine, phenylalanine, tryptophan, tyrosine, valine, salts thereof, and mixtures thereof.

15. An apparatus for concentrating and crystallizing fermentable carboxylic acids, salts, and mixtures thereof, the apparatus comprising:
at least one of a nanofiltration unit, a reverse osmosis unit, or a membrane distillation unit for separating a processed fermentation broth originating from a fermenter into a concentrate stream and a permeate stream, wherein the at least one of the nanofiltration unit, the reverse osmosis unit, or the membrane distillation unit comprises a diverting line for recycling the permeate stream; and
a cooling crystallization unit that is single-stage or multistage for crystallizing the carboxylic acid out of a solution, wherein the cooling crystallization unit comprises a recycle line for a mother liquor as coolant for the cooling crystallization unit,
wherein the at least one of the nanofiltration unit, the reverse osmosis unit, or the membrane distillation unit is connected to the cooling crystallization unit via a line for transferring the concentrate stream into the cooling crystallization unit.

16. The apparatus of claim 15 wherein the at least one of the nanofiltration unit, the reverse osmosis unit, or the membrane distillation unit comprises a two-stage reverse osmosis unit with a first stage being connected to a second stage via permeate stream line for transferring the permeate stream from the first stage to the second stage.

17. The apparatus of claim 15 wherein the cooling crystallization unit comprises a two-stage cooling crystallization unit with separate coolant systems, wherein a first stage of the cooling crystallization unit is connected to a second stage of the cooling crystallization unit via a recycle line for the mother liquor with a coolant system of the first stage, wherein a coolant system of the second stage has a separate feed line for a coolant.

18. The apparatus of claim 15 wherein the line for transferring the concentrate stream into the cooling crystallization unit is interrupted by a heat exchanger comprising:
for the concentrate stream, a feed line from the at least one of the nanofiltration unit, the reverse osmosis unit, or the membrane distillation unit and a diverting line to the cooling crystallization unit; and
for the mother liquor, a feed line from the cooling crystallization unit and a diverting line to the processed fermentation broth,
which thereby enable regenerative heat exchange between the concentrate stream and a mother liquor stream.

Assignees

• Thyssenkrupp Ind Solutions Ag
• Thyssenkrupp Ag

Inventors

• Schütze Joachim
• Braun Gerd

Classifications

• B01D61/022

  Operations & Transport · mapped topic

• B01D2317/025

  Permeate series · CPC title

• B01D15/426

  Specific type of solvent · CPC title

• B01D9/0059

  General arrangements of crystallisation plant, e.g. flow sheets · CPC title

• C07C51/43 Primary

  by change of the physical state, e.g. crystallisation · CPC title