Method for purifying organic acids

Abstract

Provided is a method for purifying organic acids, including: a first extraction which includes separating an aqueous solution of organic acids into a first organic layer and a first aqueous solution layer by adding a solvent containing an amine and an alcohol; removing the alcohol from the separated first organic layer; and a second extraction which includes separating the first organic layer from which the alcohol has been removed into a second organic layer and a second aqueous solution layer by adding water.

Claims

1. A method for purifying organic acids, comprising: a first extraction, comprising separating an aqueous solution of organic acids into a first organic layer and a first aqueous solution layer by adding a solvent containing an amine and an alcohol; removing the alcohol from the separated first organic layer; and a second extraction, comprising separating the first organic layer from which the alcohol has been removed into a second organic layer and a second aqueous solution layer by adding water.

2. The method of claim 1, wherein the aqueous solution of organic acids is a fermentation broth obtained in a microorganism-based fermentation process.

3. The method of claim 1, wherein the aqueous solution of organic acids comprises an organic acid having 2 to 10 carbon atoms containing a hydroxy group.

4. The method of claim 3, wherein the aqueous solution of organic acids comprises an organic acid having 2 to 10 carbon atoms containing a hydroxy group at a concentration of 3 to 10%.

5. The method of claim 3, wherein the aqueous solution of organic acids comprises at least one organic acid selected from the group consisting of glycolic acid, 3-hydroxypropionic acid, lactic acid and 10-hydroxydecanoic acid.

6. The method of claim 1, wherein a volume ratio of the aqueous solution of organic acids and the solvent containing the amine and the alcohol is 1:0.5 to 1:1.5 in the first extraction.

7. The method of claim 1, wherein a weight ratio of the amine and the alcohol in the solvent is 15:85 to 45:55 in the first extraction.

8. The method of claim 1, wherein the amine comprises at least one amine selected from the group consisting of tri-n-octylamine, tridecylamine, and Aliquat 336.

9. The method of claim 1, wherein the alcohol comprises at least one alcohol selected from the group consisting of 1-hexanol, 1-heptanol, and 1-octanol.

10. The method of claim 1, wherein the first extraction is carried out at a temperature of 0 to 50° C.

11. The method of claim 1, wherein removing the alcohol from the separated first organic layer comprises removing the alcohol in the first organic layer by vacuum distillation.

12. The method of claim 1, wherein the second extraction is carried out at a temperature of 50 to 100° C.

Description

DETAILED DESCRIPTION

(1) The present invention will be described in more detail with reference to the following examples. However, these examples are for illustrative purposes only, and the invention is not intended to be limited by these examples.

Experimental Example 1

Examples 1 to 5

(2) In the first extraction step, the first extraction efficiency was analyzed by varying the type and content of the extraction solvent with respect to the aqueous solution of organic acids.

(3) The aqueous solution of organic acids contains 7.2 wt % of 3-hydroxypropionic acid as a fermentation broth obtained in a microorganism-based fermentation process. For extraction, tri-n-octylamine (TOA) and Aliquat 336 were used as the amine, and 1-hexanol was used as the alcohol.

(4) After adding the alcohol and amine shown in Table 1 to the aqueous solution of organic acids and stirring at a constant temperature for a certain period of time, it was allowed to stand and separated into a first organic layer and a first aqueous solution layer to perform a first extraction.

(5) Then, the content of the organic acid contained in the separated first organic layer was analyzed using HPLC, and the result is shown in Table 1 below.

Comparative Example 1

(6) After adding the alcohol and amine in the amounts shown in Table 1 to the aqueous solution of organic acids containing 7.2 wt % of 3-hydroxypropionic acid and stirring at 30° C. for 7 hours, it was allowed to stand and separated into a first organic layer and a first aqueous solution layer to perform a first extraction.

(7) Then, the content of the organic acid contained in the separated first organic layer was analyzed using HPLC, and the result is shown in Table 1 below.

(8) TABLE-US-00001 TABLE 1 Aqueous Aqueous Solvent solution of 1st solution of Amine Alcohol organic Reaction Stirring extraction organic acids Amount Amount acids:solvent temp. time efficiency (g) Type (g) Type (g) (volume ratio) (° C.) (hr) (%) Example 1 51.0 TOA 12.4 Hexanol 29.2 1:1.0 30 7 66.8 Example 2 51.0 TOA 9.3 Hexanol 23.0 1:1.0 20 15 60.2 Aliquat 10.2 336 Example 3 51.0 TOA 9.3 Hexanol 11.5 1:0.5 20 17 52.1 Example 4 51.0 TOA 18.6 Hexanol 23.0 1:1.0 20 17 70.3 Example 5 51.0 TOA 27.9 Hexanol 34.5 1:1.5 20 17 82.6 Comp. 51.3 TOA 12.4 Dodecanol 29.2 1:1.0 30 7 50.3 Example 1

(9) Referring to Table 1, it was confirmed that Examples 1 to 5, in which the volume ratio of the aqueous solution of organic acids and the solvent containing an amine and an alcohol is 1:0.5 to 1:1.5, had a first extraction efficiency of 52.1% or more in the purification of the aqueous solution of 3-hydroxypropionic acid.

Experimental Example 2

Examples 4, 6 and 7

(10) In the first extraction step, the total amount of the extraction solvent was kept the same, and the first extraction efficiency was analyzed while changing the ratio of amine and alcohol.

(11) After adding the amine and alcohol in the amounts shown in Table 2 to the aqueous solution of organic acids containing 7.2 wt % of 3-hydroxypropionic acid and stirring at 20° C. for 17 hours, it was allowed to stand and separated into a first organic layer and a first aqueous solution layer to perform a first extraction.

(12) Then, the content of the organic acid contained in the separated first organic layer was measured using HPLC to analyze the extraction efficiency of the first extraction step, and the result is shown in Table 2 below.

(13) TABLE-US-00002 TABLE 2 Aqueous Solvent 1st solution of Amine Alcohol Amine:alcohol extraction organic acids Amount Amount (weight efficiency (g) Type (g) Type (g) ratio) (%) Example 6 51.0 TOA 6.2 Hexanol 35.4 15:85 45.8 Example 7 51.0 TOA 12.4 Hexanol 29.2 30:70 71.4 Example 4 51.0 TOA 18.6 Hexanol 23.0 45:55 70.3

(14) Referring to Table 2, it was confirmed that Examples 4, 6, and 7, in which the weight ratio of amine and alcohol is 15:85 to 45:55 in the solvent, had a first extraction efficiency of 45.8% or more in the purification of the aqueous solution of 3-hydroxypropionic acid.

Experimental Example 3

Examples 4, 5, 8 to 10

(15) After adding the amine and alcohol in the amounts shown in Table 3 to the aqueous solution of organic acids containing 7.2 wt % of 3-hydroxypropionic acid and stirring at 20° C. for 17 hours, it was allowed to stand and separated into a first organic layer and a first aqueous solution layer to perform a first extraction.

(16) Thereafter, 1-hexanol in the separated first organic layer was removed by vacuum distillation at 70° C., and water was added to the first organic layer from which the alcohol was removed, followed by stirring at 90° C. for 7 hours. Then, it was allowed to stand and separated into a second organic layer and a second aqueous solution layer to perform a second extraction.

(17) Then, the content of the organic acid contained in the separated second aqueous solution layer was measured using HPLC to analyze the extraction efficiency of the second extraction step, and the result is shown in Table 3 below.

Comparative Example 2

(18) After adding the amine and alcohol in the amounts shown in Table 3 to the aqueous solution of organic acids containing 7.2 wt % of 3-hydroxypropionic acid and stirring at 20° C. for 17 hours, it was allowed to stand and separated into a first organic layer and a first aqueous solution layer to perform a first extraction.

(19) At this time, the volume ratio of the aqueous solution of organic acids and the solvent containing the amine and alcohol was 1:1.0, and the weight ratio of the amine and alcohol in the solvent was 30:70.

(20) After adding water to the separated first organic layer and stirring at 90° C. for 7 hours, it was allowed to stand and separated into a second organic layer and a second aqueous solution layer to perform a second extraction.

(21) Then, the content of the organic acid contained in the separated second aqueous solution layer was measured using HPLC to analyze the extraction efficiency of the second extraction step, and the result is shown in Table 3 below.

(22) TABLE-US-00003 TABLE 3 1st extraction 2nd extraction Aqueous 2nd 2nd solution of 2nd aqueous extraction organic acids TOA Hexanol Removal organic solution efficiency Partition (g) (g) (g) of alcohol layer (g) layer (g) (%) coefficient Example 4 51.0 18.6 23.0 ◯ 26.0 9.0 55.3 3.691 Example 5 51.0 27.9 34.5 ◯ 41.1 20.0 69.5 4.635 Example 8 82.2 30.0 37.1 ◯ 11.0 5.5 68.6 5.281 Example 9 82.2 30.0 37.1 ◯ 11.0 11.0 81.9 5.065 Example 10 82.2 30.0 37.1 ◯ 11.0 16.5 82.4 3.387 Comp. 51.0 12.4 29.2 X 49.8 25.0 30.8 0.853 Example 2

(23) The partition coefficient refers to a ratio of the concentration of the organic acid contained in the second aqueous solution layer to the concentration of the organic acid contained in the second organic layer.

(24) Referring to Table 3, it was confirmed that Examples 4, 5, 8 to 10, which additionally performed the step of removing the alcohol after the first extraction and before the second extraction, not only had a second extraction efficiency of about 1.8 times higher than that of Comparative Example 2, but also had a distribution coefficient of about 4 times higher than that of Comparative Example 2 in the purification of the aqueous solution of 3-hydroxypropionic acid.

Experimental Example 4

Example 11

(25) An aqueous solution containing 7.2 wt % of lactic acid was prepared as an aqueous solution of organic acids. For extraction, tri-n-octylamine was used as amine and 1-hexanol was used as alcohol.

(26) After adding the alcohol and amine shown in Table 4 to the aqueous solution of organic acids and stirring at 20° C. for 17 hours, it was allowed to stand and separated into a first organic layer and a first aqueous solution layer to perform a first extraction.

(27) Then, the content of the organic acid contained in the separated first organic layer was analyzed using HPLC, and the result is shown in Table 4 below.

(28) TABLE-US-00004 TABLE 4 Aqueous Aqueous Solvent solution of 1st solution of Amine Alcohol organic Reaction Stirring extraction organic acids Amount Amount acids:solvent temp. time efficiency (g) Type (g) Type (g) (volume ratio) (° C.) (hr) (%) Example 11 82.2 TOA 30.0 Hexanol 37.1 1:1.0 20 17 97.7

Experimental Example 5

Example 11

(29) After the first extraction of the above Example 11, 1-hexanol in the first organic layer was removed by vacuum distillation at 70° C., and water was added to the first organic layer from which the alcohol was removed, followed by stirring at 90° C. for 7 hours. Then, it was allowed to stand and separated into a second organic layer and a second aqueous solution layer to perform a second extraction.

(30) Then, the content of the organic acid contained in the separated second aqueous solution layer was measured using HPLC to analyze the extraction efficiency of the second extraction step, and the result is shown in Table 5 below.

Comparative Example 3

(31) The first extraction was performed in the same manner as in the first extraction of Example 11. Thereafter, water was added to the first organic layer from which the alcohol was not removed, followed by stirring at 90° C. for 7 hours. Then, it was allowed to stand and separated into a second organic layer and a second aqueous solution layer to perform a second extraction.

(32) Then, the content of the organic acid contained in the separated second aqueous solution layer was measured using HPLC to analyze the extraction efficiency of the second extraction step, and the result is shown in Table 5 below.

(33) TABLE-US-00005 TABLE 5 1st extraction 2nd extraction Aqueous 2nd 2nd solution of 2nd aqueous extraction organic acids TOA Hexanol Removal organic solution efficiency Partition (g) (g) (g) of alcohol layer (g) layer (g) (%) coefficient Example 11 82.2 30.0 37.1 ◯ 38.0 19.0 12.4 0.352 Comp. 82.2 30.0 37.1 X 75.6 37.8 5.5 0.120 Example 3

(34) Referring to Table 5, it was confirmed that Example 11, which additionally performed the step of removing the alcohol after the first extraction and before the second extraction, not only had a second extraction efficiency of about 2.2 times higher than that of Comparative Example 3, but also had a distribution coefficient of about 2.9 times higher than that of Comparative Example 3 in the purification of the aqueous solution of lactic acid.

(35) Thus, it was confirmed that the removal of the alcohol before the second extraction changed the state of the stable complex to increase the second extraction efficiency, thereby effectively obtaining the organic acid at a high concentration.