System for synthesis of glycine under negative pressure

Abstract

This utility model discloses a system for synthesizing glycine under negative pressure, belonging to the field of glycine preparation technology. It includes a reaction vessel equipped with an ammonia inlet pipe, a chloroacetic acid inlet pipe, a hexamethylenetetramine solution inlet pipe, an inlet / outlet pipe, and a discharge pipe. The discharge pipe is equipped with a condenser, a pressure sensor, and a vacuum pump. Ammonia, high-concentration chloroacetic acid, and hexamethylenetetramine solution enter the reaction vessel through the ammonia inlet pipe, chloroacetic acid inlet pipe, and hexamethylenetetramine solution inlet pipe, respectively. The absolute pressure inside the reaction vessel is controlled at 45-53 kPa by the pressure sensor and the vacuum pump, and the reaction temperature is controlled at 79-83°C. Glycine and ammonium chloride are prepared in the reaction vessel. The reaction temperature is controlled by controlling the vacuum level of the reaction vessel. The exothermic reaction causes the material temperature to rise above the boiling point of the solvent at this pressure. The exothermic temperature is carried away by the condenser, and the condensed material is returned to the reaction vessel through the inlet / outlet pipe. After the reaction is complete, it is discharged through the discharge pipe.

Description

Technical Field

[0001] This invention belongs to the field of glycine preparation technology, specifically relating to a system for synthesizing glycine under negative pressure. Background Technology

[0002] In my country, glycine is commonly produced by the ammonolysis of chloroacetic acid. Chloroacetic acid reacts with ammonia under the catalysis of hexamethylenetetramine to produce glycine and ammonium chloride. Methanol is then added to the ammoniation reaction solution, causing glycine to precipitate, thus achieving the separation of glycine and ammonium chloride.

[0003] Traditional glycine ammoniation reactions are carried out in a batch reactor mode. Because this reaction is strongly exothermic, to ensure high heat transfer capacity of the ammoniation reactor, the concentration of reactants must not be too high to prevent solids from precipitating and adhering to the cooling pipes and reactor walls, thus affecting heat transfer. However, research has found that lower concentrations lead to a decrease in reaction yield. Utility Model Content

[0004] The purpose of this invention is to solve the problems of the prior art and provide a system for synthesizing glycine under negative pressure. Ammonia, high-concentration chloroacetic acid, and hexamethylenetetramine solution are introduced into the reactor through ammonia inlet pipe, chloroacetic acid inlet pipe, and hexamethylenetetramine solution inlet pipe, respectively. The absolute pressure inside the reactor is controlled at 45-53 kPa by a pressure sensor and a vacuum pump, and the reaction temperature is controlled at 79-83°C. Glycine and ammonium chloride are prepared in the reactor. The reaction temperature is controlled by controlling the vacuum degree of the reactor. The exothermic reaction causes the material temperature to rise above the boiling point of the solvent at this pressure. The exothermic temperature is carried away by a condenser. The condensed material is returned to the reactor through the inlet and outlet pipes. After the reaction is completed, it is discharged through the discharge pipe.

[0005] This utility model is achieved through the following technical solution:

[0006] A system for synthesizing glycine under negative pressure includes a reaction vessel, which is equipped with an ammonia feed pipe, a chloroacetic acid feed pipe, a hexamethylenetetramine solution feed pipe, an inlet pipe, an outlet pipe, and a discharge pipe. The discharge pipe is equipped with a condenser, a pressure sensor, and a vacuum pump.

[0007] Preferably, the reaction vessel is equipped with a temperature sensor.

[0008] Preferably, the reactor is equipped with a heat exchange jacket.

[0009] Preferably, the heat exchange jacket is provided with a heat exchange inlet pipe and a heat exchange outlet pipe.

[0010] Preferably, a heat exchange valve is provided on the heat exchange inlet pipe.

[0011] Preferably, the feeding pipe is equipped with a feeding valve.

[0012] Preferably, the condenser is provided with a cooling water inlet pipe and a cooling water outlet pipe.

[0013] Preferably, flow meters are installed on the ammonia inlet pipe, the chloroacetic acid inlet pipe, and the hexamethylenetetramine solution inlet pipe.

[0014] Preferably, the ammonia inlet pipe, the chloroacetic acid inlet pipe, and the hexamethylenetetramine solution inlet pipe are all equipped with inlet valves.

[0015] Preferably, the reaction vessel is equipped with a stirring device.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0017] I. This utility model provides a negative pressure synthesis system for glycine. Ammonia, high-concentration chloroacetic acid, and hexamethylenetetramine solution enter the reactor through the ammonia feed pipe, chloroacetic acid feed pipe, and hexamethylenetetramine solution feed pipe, respectively. The absolute pressure inside the reactor is controlled at 45-53 kPa by a pressure sensor and a vacuum pump, and the reaction temperature is controlled at 79-83°C. Glycine and ammonium chloride are prepared in the reactor. The reaction temperature is controlled by controlling the vacuum degree of the reactor. The exothermic reaction causes the material temperature to rise above the boiling point of the solvent at this pressure. The exothermic temperature is carried away by the condenser. The condensed material is returned to the reactor through the inlet and outlet pipes. After the reaction is completed, it is discharged through the discharge pipe.

[0018] II. The present invention provides a negative pressure synthesis system for glycine, wherein at the start of the reaction, the temperature inside the reactor is controlled by controlling the opening of the heat exchange valve.

[0019] III. The present invention provides a negative pressure synthesis system for glycine, with the flow meter and feed valve designed to facilitate precise control of the feed rates of ammonia, high-concentration chloroacetic acid, and hexamethylenetetramine solution.

[0020] IV. The present invention provides a negative pressure synthesis system for glycine, and the addition of a stirring device makes the reaction more thorough. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this utility model.

[0023] The components include: 1. Reactor; 2. Ammonia feed pipe; 3. Chloroacetic acid feed pipe; 4. Hexamethylenetetramine solution feed pipe; 5. Inlet and outlet pipes; 6. Feed pipe; 7. Condenser; 8. Pressure sensor; 9. Vacuum pump; 10. Temperature sensor; 11. Heat exchange jacket; 12. Heat exchange inlet pipe; 13. Heat exchange outlet pipe; 14. Heat exchange valve; 15. Feed valve; 16. Cooling water inlet pipe; 17. Cooling water outlet pipe; 18. Flow meter; 19. Feed valve; 20. Stirring device. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment provides a system for synthesizing glycine under negative pressure, including a reaction vessel 1. The reaction vessel 1 is equipped with an ammonia inlet pipe 2, a chloroacetic acid inlet pipe 3, a hexamethylenetetramine solution inlet pipe 4, an inlet / outlet pipe 5, and a discharge pipe 6. The discharge pipe 6 is equipped with a condenser 7, a pressure sensor 8, and a vacuum pump 9.

[0027] Example 2

[0028] like Figure 2 As shown, this embodiment provides a system for synthesizing glycine under negative pressure, including a reaction vessel 1. The reaction vessel 1 is equipped with an ammonia inlet pipe 2, a chloroacetic acid inlet pipe 3, a hexamethylenetetramine solution inlet pipe 4, an inlet / outlet pipe 5, and a discharge pipe 6. The discharge pipe 6 is equipped with a condenser 7, a pressure sensor 8, and a vacuum pump 9.

[0029] A temperature sensor 10 is installed on the reactor 1.

[0030] The reactor 1 is equipped with a heat exchange jacket 11.

[0031] The heat exchange jacket 11 is provided with a heat exchange inlet pipe 12 and a heat exchange outlet pipe 13.

[0032] A heat exchange valve 14 is provided on the heat exchange inlet pipe 12.

[0033] The feeding pipe 6 is equipped with a feeding valve 15.

[0034] The condenser 7 is equipped with a cooling water inlet pipe 16 and a cooling water outlet pipe 17.

[0035] Flow meters 18 are installed on the ammonia inlet pipe 2, the chloroacetic acid inlet pipe 3, and the hexamethylenetetramine solution inlet pipe 4.

[0036] The ammonia inlet pipe 2, the chloroacetic acid inlet pipe 3, and the hexamethylenetetramine solution inlet pipe 4 are all equipped with inlet valves 19.

[0037] The reactor 1 is equipped with a stirring device 20. The stirring device 20 includes a stirring motor, a stirring shaft, and a stirring paddle. The stirring motor is located at the upper end of the reactor 1, and its output end is connected to the stirring shaft. The stirring shaft passes through the reactor and enters the interior of the reactor. The stirring paddle is located on the stirring shaft inside the reactor 1.

[0038] The condenser 7, pressure sensor 8, vacuum pump 9, temperature sensor 10, heat exchange jacket 11, heat exchange valve 14, flow meter 18, feed valve 19, and stirring motor are all existing technologies and will not be described in detail here. Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0039] I. This utility model provides a negative pressure synthesis system for glycine. Ammonia, high-concentration chloroacetic acid, and hexamethylenetetramine solution enter the reactor 1 through the ammonia inlet pipe 2, the chloroacetic acid inlet pipe 3, and the hexamethylenetetramine solution inlet pipe 4, respectively. The absolute pressure inside the reactor 1 is controlled at 45-53 kPa by the pressure sensor 8 and the vacuum pump 9, and the reaction temperature is controlled at 79-83℃. Glycine and ammonium chloride are prepared in the reactor 1. The reaction temperature is controlled by controlling the vacuum degree of the reactor 1. The exothermic reaction causes the material temperature to rise above the boiling point of the solvent at this pressure. The exothermic temperature is carried away by the condenser 7. The material condensed by the condenser 7 is returned to the reactor 1 through the inlet and outlet pipes 5. When the reaction is completed, it is discharged through the discharge pipe 6.

[0040] II. The present invention provides a negative pressure synthesis system for glycine. At the start of the reaction, the temperature inside the reactor 1 is controlled by adjusting the opening of the heat exchange valve 14. Steam enters the heat exchange jacket 11 through the heat exchange inlet pipe 12, and the condensate after heat exchange is discharged through the heat exchange outlet pipe 13.

[0041] III. The present invention provides a negative pressure synthesis system for glycine, with the flow meter 18 and feed valve 19 for convenient and precise control of the feed rates of ammonia, high-concentration chloroacetic acid and hexamethylenetetramine solution.

[0042] IV. The present invention provides a negative pressure synthesis system for glycine, and the setting of the stirring device 20 makes the reaction more thorough.

[0043] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A system for the synthesis of glycine under negative pressure, characterized by: The reactor includes a reaction vessel (1), which is equipped with an ammonia feed pipe (2), a chloroacetic acid feed pipe (3), a hexamethylenetetramine solution feed pipe (4), an inlet pipe (5), and a discharge pipe (6). The discharge pipe (6) is equipped with a condenser (7), a pressure sensor (8), and a vacuum pump (9).

2. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: A temperature sensor (10) is installed on the reactor (1).

3. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: The reactor (1) is equipped with a heat exchange jacket (11).

4. The system for synthesizing glycine under negative pressure according to claim 3, characterized in that: The heat exchange jacket (11) is provided with a heat exchange inlet pipe (12) and a heat exchange outlet pipe (13).

5. The system for synthesizing glycine under negative pressure according to claim 4, characterized in that: A heat exchange valve (14) is provided on the heat exchange inlet pipe (12).

6. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: A discharge valve (15) is provided on the discharge pipe (6).

7. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: The condenser (7) is provided with a cooling water inlet pipe (16) and a cooling water outlet pipe (17).

8. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: Flow meters (18) are installed on the ammonia inlet pipe (2), chloroacetic acid inlet pipe (3) and hexamethylenetetramine solution inlet pipe (4).

9. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: The ammonia inlet pipe (2), chloroacetic acid inlet pipe (3) and hexamethylenetetramine solution inlet pipe (4) are all equipped with inlet valves (19).

10. The system for synthesizing glycine under negative pressure according to claim 1, characterized in that: The reactor (1) is equipped with a stirring device (20).

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