Preparation process of glycine
By using a supported catalyst, the support is hydrotalcite and the active component precursor includes lanthanum chloride, the problem of low yield and low purity in the traditional glycine preparation process is solved, efficient and environmentally friendly glycine preparation is achieved, and its application field is expanded.
Patent Information
- Application Number
- CN202411883357.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-03-21
AI Technical Summary
The traditional glycine preparation process has problems such as low yield, low purity and serious environmental pollution, which is difficult to meet the needs of further expanding the application field of glycine.
A supported catalyst is used, the support is hydrotalcite, and the active component precursor includes lanthanum chloride. By adjusting the pH value and controlling the reaction conditions, the yield and purity of glycine are improved.
It significantly improves the yield and purity of glycine, reduces production costs, and reduces environmental pollution, expands the application potential of glycine in food, medicine and other industries.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of glycine preparation, and in particular to a process for preparing glycine. Background Art
[0002] Glycine, also known as aminoacetic acid, is an important amino acid component of the endogenous antioxidant reduced glutathione. When the body encounters severe stress, glycine is often supplemented as an exogenous supplement, so it is also considered a semi-essential amino acid. It has a variety of biological activities, including non-addictive central sedative effects, which can inhibit the heat production of the hypothalamic thermoregulatory center and the gray matter around the midbrain aqueduct, thereby achieving an antipyretic effect. In addition, glycine can enhance the body's tolerance to hypoxic environments and show a certain anti-fatigue effect. It also has the effect of relaxing smooth muscles, helping to relieve tension and promote sleep. As one of the basic amino acids that make up protein, glycine actively participates in the protein synthesis process in the body. Studies have also found that glycine may lower blood pressure by regulating the dilation and contraction of blood vessels. Given the multiple functions of glycine in antipyretic analgesia, anti-fatigue, improving sleep quality, promoting protein synthesis, and lowering blood pressure, it has a wide range of applications in many industries such as food, medicine, and cosmetics.
[0003] Traditional glycine preparation processes include Streeck process, monochloroacetic acid amination process and direct Hein process. Among them, monochloroacetic acid amination process has become the main method for producing glycine because of its relatively mature process route. However, this method also faces problems such as unstable product quality, high production cost and serious environmental pollution. Therefore, it is particularly important to develop a preparation process that can improve the yield and purity of glycine, which plays a key role in further expanding the application field of glycine. Summary of the invention
[0004] The invention provides a preparation process of glycine, which solves the problems of low glycine yield and low purity in the related art.
[0005] The technical solution of the present invention is as follows: The present invention provides a process for preparing glycine, comprising the following steps: S1. Mixing monoethanolamine and water, adjusting the pH value to alkaline, adding a catalyst, reacting, filtering, and obtaining a glycine salt solution; S2, acidifying, crystallizing, and separating the glycine salt solution to obtain glycine; The catalyst is a supported catalyst, the carrier of the supported catalyst is hydrotalcite, and the active component precursor of the supported catalyst includes lanthanum chloride; The mass ratio of the carrier to the active component precursor is 100:3-10.
[0006] As a further technical solution, the mass ratio of the carrier to the active component precursor is 100:6~8.
[0007] When the mass ratio of the carrier to the active component precursor is 100:6-8, the yield and purity of glycine can be further improved.
[0008] As a further technical solution, the preparation method of the supported catalyst comprises the following steps: dissolving the active component precursor in water, adding the hydrotalcite, adding sodium hydroxide solution, mixing evenly, and drying to obtain the supported catalyst.
[0009] As a further technical solution, the active component precursor also includes yttrium chloride, and the mass ratio of the lanthanum chloride to the yttrium chloride is 3:1.
[0010] When the active component precursor also includes yttrium chloride, lanthanum chloride and yttrium chloride have a synergistic effect and can further improve the yield and purity of glycine.
[0011] As a further technical solution, the mass fraction of the sodium hydroxide solution is 3% to 5%, and the mass ratio of the hydrotalcite to the sodium hydroxide solution is 1:1.05.
[0012] As a further technical solution, the hydrotalcite is a modified hydrotalcite, and the raw materials of the modified hydrotalcite include hydrotalcite and N,N-diphenylguanidine.
[0013] The inventors found that the yield and purity of glycine can be further improved by modifying hydrotalcite with N,N-diphenylguanidine. The reason may be that N,N-diphenylguanidine exists on hydrotalcite, which stabilizes the catalytic system and allows the catalyst to better adsorb the raw materials, thereby further improving the catalytic effect after combining with the active components, and further improving the yield and purity of glycine.
[0014] As a further technical solution, the mass ratio of the hydrotalcite to the N,N-diphenylguanidine is 100:8-12.
[0015] When the mass ratio of hydrotalcite to N,N-diphenylguanidine is 100:8-12, the yield and purity of glycine can be further improved.
[0016] As a further technical solution, the preparation method of the modified hydrotalcite comprises the following steps: dissolving the N,N-diphenylguanidine in ethanol, adding the hydrotalcite, dispersing evenly, and drying to obtain the modified hydrotalcite.
[0017] As a further technical solution, in step S1, the mass ratio of the monoethanolamine, the catalyst and the water is 3~7g:20mg:15g.
[0018] As a further technical solution, in step S1, during the reaction, the temperature is 50-60°C and the time is 2-4 hours; in step S1, when the pH value is adjusted to alkaline, a sodium hydroxide solution with a mass fraction of 10%-15% is used to adjust the pH value to 7.5-8.5.
[0019] As a further technical solution, in step S2, during the acidification, a hydrochloric acid solution with a mass fraction of 10% to 15% is used to adjust the pH value to 5.8 to 6.5.
[0020] The working principle and beneficial effects of the present invention are: In the present invention, glycine can be prepared by using monoethanolamine as a raw material under the action of a catalyst. The catalyst is a supported catalyst, the carrier is hydrotalcite, and the active component precursor includes lanthanum chloride. When the carrier is hydrotalcite and the active component precursor includes lanthanum chloride, the prepared catalyst has a higher active site, can efficiently adsorb monoethanolamine, and improve the catalytic effect, so that the prepared glycine has a higher yield and purity. DETAILED DESCRIPTION
[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] In the following examples and comparative examples, the hydrotalcite is magnesium-aluminum hydrotalcite with a particle size of 200 μm, a bulk density of 0.31 g / mL, and a MgO / Al2O3 ratio of 4.0, purchased from Zhejiang Huate New Materials Co., Ltd.
[0023] Example 1 A process for preparing glycine comprises the following steps: S1. Mix 3 g of monoethanolamine and 15 g of water, adjust the pH value to 7.5 with a 10% sodium hydroxide solution, add 20 mg of catalyst, react at 50°C for 4 h, filter, and obtain a glycine salt solution; S2, adjusting the pH value of the glycine salt solution to 5.8 with a 10% hydrochloric acid solution, acidifying, crystallizing, and separating to obtain 3.620 g of glycine; The catalyst is a supported catalyst, the support of the supported catalyst is hydrotalcite, and the active component precursor of the supported catalyst includes only lanthanum chloride; the mass ratio of hydrotalcite to lanthanum chloride is 100:3; The preparation method of the supported catalyst comprises the following steps: dissolving 3 parts of lanthanum chloride in 20 parts of water, adding 100 parts of hydrotalcite, adding 105 parts of 4% by mass sodium hydroxide solution, mixing evenly, and drying to obtain the supported catalyst.
[0024] Example 2 S1. Mix 7 g of monoethanolamine and 15 g of water, adjust the pH value to 8.5 with a 15% mass fraction sodium hydroxide solution, add 20 mg of catalyst, react at 60°C for 2 h, filter, and obtain a glycine salt solution; S2, adjusting the pH value of the glycine salt solution to 6.5 with a 15% hydrochloric acid solution, acidifying, crystallizing, and separating to obtain 8.483 g of glycine; The catalyst is a supported catalyst, the support of the supported catalyst is hydrotalcite, and the active component precursor of the supported catalyst includes only lanthanum chloride; the mass ratio of hydrotalcite to lanthanum chloride is 100:10; The preparation method of the supported catalyst comprises the following steps: dissolving 10 parts of lanthanum chloride in 20 parts of water, adding 100 parts of hydrotalcite, adding 105 parts of 4% by mass sodium hydroxide solution, mixing evenly, and drying to obtain the supported catalyst.
[0025] Example 3 The only difference between this embodiment and embodiment 2 is that, in this embodiment, the mass ratio of hydrotalcite to lanthanum chloride is 100:4; wherein 8.479 g of glycine is obtained.
[0026] Example 4 The only difference between this embodiment and embodiment 2 is that, in this embodiment, the mass ratio of hydrotalcite to lanthanum chloride is 100:6; wherein 8.503 g of glycine is obtained.
[0027] Example 5 The only difference between this embodiment and embodiment 2 is that, in this embodiment, the mass ratio of hydrotalcite to lanthanum chloride is 100:8; wherein 8.504 g of glycine is obtained.
[0028] Example 6 The only difference between this embodiment and embodiment 5 is that in this embodiment, the carrier of the supported catalyst is hydrotalcite, and the active component precursor of the supported catalyst includes only yttrium chloride; the mass ratio of hydrotalcite to yttrium chloride is 100:8; and 8.495 g of glycine is obtained.
[0029] Example 7 The only difference between this embodiment and embodiment 5 is that in this embodiment, the active component precursors of the supported catalyst include lanthanum chloride and yttrium chloride; the mass ratio of lanthanum chloride to yttrium chloride is 3:1; and 8.513 g of glycine is obtained.
[0030] Example 8 The difference between this embodiment and embodiment 5 is that in this embodiment, the hydrotalcite is a modified hydrotalcite, and its preparation method comprises the following steps: dissolving 6 parts of N,N-diphenylguanidine in 100 parts of ethanol, adding 100 parts of hydrotalcite, dispersing evenly, and drying to obtain the modified hydrotalcite; The preparation method of the supported catalyst comprises the following steps: dissolving 6 parts of lanthanum chloride and 2 parts of yttrium chloride in 20 parts of water, adding 100 parts of the modified hydrotalcite, adding 105 parts of 4% by mass sodium hydroxide solution, mixing evenly, and drying to obtain the supported catalyst; wherein 8.543 g of glycine is obtained.
[0031] Example 9 The only difference between this embodiment and embodiment 8 is that in this embodiment, 13 parts of N,N-diphenylguanidine are added; among them, 8.546 g of glycine is obtained.
[0032] Example 10 The only difference between this embodiment and embodiment 8 is that in this embodiment, 8 parts of N,N-diphenylguanidine are added; among them, 8.572 g of glycine is obtained.
[0033] Embodiment 11 The only difference between this embodiment and embodiment 8 is that in this embodiment, 12 parts of N,N-diphenylguanidine are added; among them, 8.575 g of glycine is obtained.
[0034] Comparative Example 1 The only difference between this comparative example and Example 1 is that in this example, the catalyst only includes hydrotalcite; wherein 8.350 g of glycine is obtained.
[0035] Comparative Example 2 The only difference between this comparative example and Example 1 is that, in this example, the catalyst only includes lanthanum chloride; wherein 7.606 g of glycine is obtained.
[0036] Comparative Example 3 The difference between this comparative example and Example 1 is that in this example, no catalyst is added; wherein 8.429 g of glycine is obtained.
[0037] Comparative Example 4 A process for preparing glycine comprises the following steps: S1. Mix monoethanolamine and water in a mass volume ratio of 3 g:15 mL, adjust the pH value to 7.5 with a 10% mass fraction sodium hydroxide solution, add a catalyst, react at 50°C for 4 hours, filter, and obtain a glycine salt solution; the mass ratio of monoethanolamine to catalyst is 3 g:20 mg; S2, adjusting the pH value of the glycine salt solution to 5.8 with a 10% hydrochloric acid solution, acidifying, crystallizing, and separating to obtain 3.615 g of glycine; The catalyst comprises hydrotalcite and lanthanum chloride; the mass ratio of the hydrotalcite to the lanthanum chloride is 100:3.
[0038] The yield of glycine prepared in Examples 1 to 11 and Comparative Examples 1 to 4 was calculated according to the following formula: yield (%) = actual mass of glycine (g) × purity / theoretical mass of glycine (g) × 100%, and the purity was tested by high performance liquid chromatography. The chromatographic conditions were as follows: chromatographic column (aminopropyl bonded silica gel chromatographic column); mobile phase (a mixed solution of acetonitrile and phosphate buffer in a volume ratio of 72:28), flow rate of 1.0 mL / min, and injection volume of 20 μL.
[0039] The test results are shown in Table 1 below: Table 1 Yield and purity of glycine in Examples 1 to 11 and Comparative Examples 1 to 4
[0040] Compared with Comparative Examples 1 to 4, the yield and purity of glycine prepared in Example 1 are significantly improved, indicating that when the catalyst is a supported catalyst, the carrier is hydrotalcite, and the active component precursor includes lanthanum chloride, the prepared catalyst has a higher active site and can prepare glycine with higher yield and purity.
[0041] Compared with Examples 2-3, the yield and purity of glycine prepared in Examples 4-5 are improved, indicating that when the mass ratio of the carrier to the active component precursor is 100:6-8, the yield and purity of glycine can be further improved.
[0042] Compared with Examples 5 to 6, the yield and purity of glycine prepared in Example 7 are improved, indicating that when the active component precursor also includes yttrium chloride, lanthanum chloride and yttrium chloride have a synergistic effect, which can further improve the yield and purity of glycine.
[0043] Compared with Example 7, the yield and purity of glycine prepared in Examples 8 to 11 are improved, indicating that the yield and purity of glycine can be further improved after the hydrotalcite is modified by N,N-diphenylguanidine.
[0044] Compared with Examples 8 to 9, the yield and purity of glycine prepared in Examples 10 to 11 are improved, indicating that when the mass ratio of hydrotalcite to N,N-diphenylguanidine is 100:8 to 12, the yield and purity of glycine can be further improved.
[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A process for preparing glycine, characterized in that: The following steps are involved: S1. Mixing monoethanolamine and water, adjusting the pH value to alkaline, adding a catalyst, reacting, filtering, and obtaining a glycine salt solution; S2, acidifying, crystallizing, and separating the glycine salt solution to obtain glycine; The catalyst is a supported catalyst, the carrier of the supported catalyst is hydrotalcite, and the active component precursor of the supported catalyst includes lanthanum chloride; The mass ratio of the carrier to the active component precursor is 100:3-10.
2. A process for preparing glycine according to claim 1, characterized in that: The mass ratio of the carrier to the active component precursor is 100:6-8.
3. A process for preparing glycine according to claim 1, characterized in that: The preparation method of the supported catalyst comprises the following steps: dissolving the active component precursor in water, adding the hydrotalcite, adding a sodium hydroxide solution, mixing evenly, and drying to obtain the supported catalyst.
4. A process for preparing glycine according to claim 1, characterized in that: The active component precursor also includes yttrium chloride, and the mass ratio of the lanthanum chloride to the yttrium chloride is 3:
1.
5. A process for preparing glycine according to claim 1, characterized in that: The hydrotalcite is a modified hydrotalcite, and the raw materials of the modified hydrotalcite include hydrotalcite and N,N-diphenylguanidine.
6. A process for preparing glycine according to claim 5, characterized in that: The mass ratio of the hydrotalcite to the N,N-diphenylguanidine is 100:8-12.
7. A process for preparing glycine according to claim 5, characterized in that: The preparation method of the modified hydrotalcite comprises the following steps: dissolving the N,N-diphenylguanidine in ethanol, adding the hydrotalcite, dispersing evenly, and drying to obtain the modified hydrotalcite.
8. A process for preparing glycine according to claim 1, characterized in that: In step S1, the mass ratio of the monoethanolamine, the catalyst and the water is 3-7 g:20 mg:15 g.
9. A process for preparing glycine according to claim 1, characterized in that: In step S1, during the reaction, the temperature is 50-60° C. and the time is 2-4 hours; in step S1, when the pH value is adjusted to alkaline, a sodium hydroxide solution with a mass fraction of 10%-15% is used to adjust the pH value to 7.5-8.
5.
10. A process for preparing glycine according to claim 1, characterized in that: In step S2, during the acidification, a hydrochloric acid solution with a mass fraction of 10% to 15% is used to adjust the pH value to 5.8 to 6.5.