A PROCESS FOR PRODUCING TAURINE

Abstract

The present application provides a process for preducing taurine, comprising the steps as follows: (a) mixing isethionic acid with taurine salt solution until the system pH reaches a certain value in a range from 5.0 to 9.5; (b) separating liquid phase and solid phase of the system; wherein said solid phase is the crude product of taurine, and said liquid phase is isethionate solution; (c) reacting ammonia solution with said liquid phase obtained from step (b) to obtain taurine salt solution. It uses isethionic acid to adjust the pH of the taurine salt solution, avoiding the problem causing by using sulphate acid to adjust the pH in the traditional process. By the recycling use of the cations in taurine salts, a new raw material or reagent does not need to be added which is benefit to reducing the use of dangerous chemical materials, simplifying the production process greatly, improving the utilization rate of raw materials, increasing the yield of the product and decreasing production cost significantly.

Claims

1. A process for producing taurine, comprising the steps as follows: (a) mixing isethionic acid with taurine salt solution until the system pH reaches a certain value in a range from 5.0 to 9.5; (b) separating liquid phase and solid phase of the system; wherein said solid phase is the crude product of taurine, and said liquid phase is isethionate solution; (c) reacting ammonia solution with said liquid phase obtained from step (b) to obtain taurine salt solution.

2. The process according to claim 1, wherein said taurine salt is at least one selected from ammonium salts of taurine, alkali metal salts of taurine, alkaline earth salts of taurine.

3. The process according to claim 1, wherein in step (a), said taurine salt solution is obtained by dissolving taurine salt in water and/or recycling of said taurine salt solution obtained in step (b).

4. The process according to claim 1, wherein in step (a), the mass percent concentration of taurine salt in said taurine salt solution is in a range from 35 wt % to 60 wt %.

5. The process according to claim 1, wherein in step (a), the mass percent concentration of taurine salt in said taurine salt solution is in a range from 40 wt % to 50 wt %.

6. The process according to claim 1, wherein step (a) is that mixing isethionic acid with taurine salt solution until the system pH reaches a certain value in a range from 5.5 to 9.0.

7. The process according to claim 1, wherein in step (b), separation of liquid phase and solid phase of the system is carried out at a temperature range from 0 C. to 50 C.

8. The process according to claim 1, wherein in step (b), separation of liquid phase and solid phase of the system is carried out at a temperature range from 10 C. to 20 C.

9. The process according to claim 1, wherein said process for producing taurine is a batch process.

10. The process according to claim 1, wherein said process for producing taurine is a continuous process.

Description

DESCRIPTION OF THE FIGURES

[0021] FIG. 1 shows a schematic flowchart of an embodiment provided by the present application for the production of taurine.

[0022] FIG. 2 shows a schematic flowchart of another embodiment provided by the present application for the production of taurine.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0023] The following examples will illustrate the practice of the present invention by combining with the Figures but are not intended to limit its scope.

[0024] In the examples, all reagents are purchased commercially if there is no special illustration.

[0025] In the examples, taurine was determined with LC10AT High Performance Liquid Chromatography (HPLC) produced by Shimadzu Company; sodium hydroxyethyl sulfonate was determined with ICS900 Ion Chromatography produced by Dionex Corporation.

[0026] FIG. 1 shows a schematic flowchart of an embodiment provided by the present application for the production of taurine which is a continuous process for producing taurine. Reactor 1 and Reactor 2 both are Continuous Stirred Tank Reactor (abbreviated as CSTR). Isethionic acid and taurine salt solution as the materials were added into Reactor 1; and the pH was adjusted to a certain value in a range from 5.0 to 9.5 by adjusting each amount of isethionic acid and taurine salt solution. The solid-liquid phase materials which were exported from Reactor 1 entered into a filter; after being filtered, the solid phase was obtained as the crude product of taurine and the liquid phase passing through the filter (isethionate solution) entered into Reactor 2. Reactor 2 was a Pressurized Reactor. The isethionate solution passing through the filter reacted with ammonia solution in Reactor 2 to obtain taurine salt solution which was recycled back to Reactor 1.

[0027] FIG. 2 shows a schematic flowchart of another embodiment provided by the present application for the production of taurine which is a continuous process or a batch process for producing taurine. Reactor 1 and Reactor 2 are Continuous Stirred tank Reactor or Batch Tank Reactor. Isethionic acid and taurine salt solution as the materials were added into Reactor 1; and the pH was adjusted to a certain value in a range from 5.0 to 9.5 by adjusting each amount of isethionic acid and taurine salt solution. When Reactor 1 was a Continuous Stirred Tank Reactor, the materials were continuously fed into Reactor 1 and the solid-liquid phase materials were exported continuously, entering into a filter continuously and being filtered continuously. When Reactor 1 is a Batch Tank Reactor, all of the solid-liquid phase materials were taken out from Reactor 1 after the reaction was completed, entering into a filter to be intermittently filtered; after being intermittently filtered, the solid phase was obtained as the crude product of taurine and the liquid phase passing through the filter (isethionate solution) entered into Reactor 2. Reactor 2 was a Pressurized Reactor. The isethionate solution passing through the filter reacted with ammonia solution in Reactor 2 to obtain taurine salt solution which could be kept as the product or also could be recycled back to Reactor 1 as a material for reacting again.

Example 1

[0028] 500 mL of aqueous sodium taurine solution with mass percent concentration of 46 wt % was added into a reaction bottle, and then isethionic acid was added slowly under stirring at room temperature until the pH reached to 5.5. The system was filtered to obtain 216 g of the crude product of taurine after the system temperature was dropped to 15 C. The filtrate was transferred into a reaction bottle, and then 1710 g of ammonia solution with mass percent concentration of 26.5% was mixed with the above filtrate. In autoclave, the reaction was carried out at 250 C. and 10 MPa pressure for 1 h. 697 g of sodium taurine solution was obtained after cooling, discharging and subsequently removing ammonia by evaporation. The content of taurine was determined by HPLC. The content of sodium isethionate was determined by Ion Chromatography. The results were shown in Table 1; wherein the percentages in the table all were mass percentage.

TABLE-US-00001 TABLE 1 Each component content in the crude Content of sodium taurine in the product of taurine sodium taurine solution Content of taurine: 87.88% Content of sodium taurine: 46.15% Content of water: 6.92% Content of sodium isethionate: 4.40%

Example 2

[0029] 500 mL of sodium taurine solution obtained in Example 1 was added into a reaction bottle, and then isethionic acid was added slowly under stirring at room temperature until the pH reached to 7.5. The system was filtered to obtain 229 g of the crude product of taurine after the system temperature was dropped to 15 C. The filtrate was transferred into a reaction bottle, and then 1700 g of ammonia solution with mass percent concentration of 25.8% was mixed with the above filtrate. In autoclave, the reaction was carried out at 253 C. and 10.5 MPa pressure for 1 h. 615 g of sodium taurine solution was obtained after cooling, discharging and subsequently removing ammonia by evaporation. The content of taurine was determined by HPLC. The content of sodium isethionate was determined by Ion Chromatography. The results were shown in Table 2; wherein the percentages in the table all were mass percentage.

TABLE-US-00002 TABLE 2 Each component content in the crude Content of sodium taurine in the product of taurine sodium taurine solution Content of taurine: 88.64% Content of sodium taurine: 46.35% Content of water: 6.34% Content of sodium isethionate: 4.42%

Example 3

[0030] 500 mL of sodium taurine solution with mass percent concentration of 46 wt % was added into a reaction bottle, and then isethionic acid was added slowly under stirring at room temperature until the pH reached to 8.5. The system was filtered to obtain 223 g of the crude product of taurine after the system temperature was dropped to 15 C. The filtrate was transferred into a reaction bottle, and then 1690 g of ammonia solution with mass percent concentration of 26.0% was mixed with the above filtrate. In autoclave, the reaction was carried out at 256 C. and 10 MPa pressure for 1 h. 580 g of sodium taurine solution was obtained after cooling, discharging and subsequently removing ammonia by evaporation. The content of taurine was determined by HPLC. The content of sodium isethionate was determined by Ion Chromatography. The results were shown in Table 3; wherein the percentages in the table all were mass percentage.

TABLE-US-00003 TABLE 3 Each component content in the crude Content of sodium taurine in the product of taurine sodium taurine solution Content of taurine: 90.82% Content of sodium taurine: 46.10% Content of water: 5.68% Content of sodium isethionate: 3.0%

Example 4

[0031] 500 mL of aqueous sodium taurine solution with mass percent concentration of 46 wt % was added into a reaction bottle, and then isethionic acid was added slowly under stirring at room temperature until the pH reached to 9.0. The system was filtered to obtain 201 g of the crude product of taurine after the system temperature was dropped to 15 C. The filtrate was transferred into a reaction bottle, and then 1680 g of ammonia solution with mass percent concentration of 25.9% was mixed with the above filtrate. In autoclave, the reaction was carried out at 258 C. and 11 MPa pressure for 1 h. 585 g of sodium taurine solution was obtained after cooling, discharging and subsequently removing ammonia by evaporation. The content of taurine was determined by HPLC. The content of sodium isethionate was determined by Ion Chromatography. The results were shown in Table 4; wherein the percentages in the table all were mass percentage.

TABLE-US-00004 TABLE 4 Each component content in the crude Content of sodium taurine in the product of taurine sodium taurine solution Content of taurine: 91.5% Content of sodium taurine: 45.80% Content of water: 4.93% Content of sodium isethionate: 3.07%

Example 5

[0032] 600 mL of sodium taurine solution obtained in Example 2 with mass percent concentration of 46.35% was added into a reaction bottle, and then isethionic acid was added slowly under stirring at room temperature until the pH reached to 7.8. The system was filtered to obtain 221 g of the crude product of taurine after the system temperature was dropped to 15 C. The filtrate was transferred into a reaction bottle, and then 1700 g of ammonia solution with mass percent concentration of 25.9% was mixed with the above filtrate. In autoclave, the reaction was carried out at 258 C. and 11 MPa pressure for 1.5 h. 605 g of sodium taurine solution was obtained after cooling, discharging and subsequently removing ammonia by evaporation. The content of taurine was determined by HPLC. The content of sodium isethionate was determined by Ion Chromatography. The results were shown in Table 5; wherein the percentages in the table all were mass percentage.

TABLE-US-00005 TABLE 5 Each component content in the crude Content of sodium taurine in the product of taurine sodium taurine solution Content of taurine: 89.5% Content of sodium taurine: 46.25% Content of water: 6.03% Content of sodium isethionate: 3.42%

[0033] It will be understood that the foregoing Examples are only some examples of the present application, but not limited to the application in any form. Although the optimized examples of the present application are illustrated as above, they do not limit the application. In view of the instant disclose various modifications of the present application will be self-evident to those skilled in the art and are to be included within the spirit and purview of the present application and the scope of the appended claims.