A device for the production of glycine

Abstract

This utility model discloses a glycine production apparatus, including a mixing vessel, a tubular reactor, an alcohol precipitation vessel, a crystallization vessel, a catalytic liquid transfer tank, a vacuum dryer, and a recrystallization vessel. The glycine production apparatus provided by this utility model can be used to produce glycine via the ammonolysis of chloroacetic acid. This apparatus produces glycine through continuous feeding and continuous discharging, improving production efficiency and equipment utilization. Simultaneously, through separation processing, the catalyst hexamethylenetetramine is recycled, further reducing production costs.

Description

Technical Field

[0001] This utility model relates to the field of glycine preparation technology, and in particular to a glycine production apparatus. Background Technology

[0002] Glycine, also known as aminoacetic acid, is one of the simplest amino acids in terms of structure. Due to its structural characteristics and outstanding reactivity, it has become an important chemical intermediate and is widely used in medicine, pesticides, nitrogen fertilizers, feed, and food. Methods for synthesizing glycine can be categorized into chemical and biological methods, with chemical methods being the mainstream. These methods mainly include: chloroacetic acid ammonolysis, the Strecker process, the Hydantoin process, and phase transfer catalysis.

[0003] Among them, the ammonolysis of chloroacetic acid is widely recognized by the market due to its reaction selectivity and production safety, and has become the mainstream method for glycine production in China. The ammonolysis of chloroacetic acid uses chloroacetic acid and ammonia water as raw materials, and a substitution reaction is carried out under the action of hexamethylenetetramine catalyst. This reaction is carried out at normal pressure and low temperature, and does not require a high acid-base reaction environment. The raw materials used have low toxicity, and the reaction selectivity is good; however, the reaction time is long, it is a batch reaction, the product purification cost is high, the amount of catalyst used in the reaction is large, and it is not easy to recover. To address these problems, researchers have conducted modification studies on the ammonolysis of chloroacetic acid and achieved certain results. For example, patent CN111187173B discloses a continuous glycine synthesis method. First, chloroacetic acid and ammonia gas are exothermically converted into salts, and then a mixture of hexamethylenetetramine and ammonia water is fed in stages. The reaction selectivity is controlled by the reaction temperature and pH. The mixed crystal mother liquor rich in hexamethylenetetramine obtained by separation is recycled to the batching process as the dissolved water for chloroacetic acid and ammonia, realizing the recycling of hexamethylenetetramine. This method results in a lower reaction system concentration, which reduces the reaction rate and prolongs the reaction time. The segmented feeding method is necessarily a batch reactor reaction, not a true continuous process, and does not improve the efficiency of the equipment. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a glycine production apparatus that operates through continuous feeding and discharging, maintaining the high selectivity of the chloroacetic acid ammonolysis process while enabling the recycling of the catalyst hexamethylenetetramine.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A glycine production apparatus includes: a mixing vessel, a tubular reactor, an alcohol precipitation vessel, a crystallization vessel, a catalyst transfer tank, a vacuum dryer, and a recrystallization vessel. The mixing vessel is provided with a mixing vessel inlet and a catalyst inlet at the top, a mixing vessel outlet at the bottom, and a mixing vessel constant temperature heat exchanger on the outer wall. The mixing vessel inlet is connected to a chloroacetic acid aqueous solution delivery pipeline via a pipeline and connected in series with a valve, a transfer pump, and an electronic flow meter. The tubular reactor is provided with a tubular reactor inlet and a tubular reactor outlet at both ends. The tubular reactor inlet is connected to the mixing vessel outlet and the ammonia delivery pipeline through a pipeline and a first three-way valve, respectively. The top of the alcohol precipitation vessel is provided with an alcohol precipitation vessel liquid inlet and an alcohol precipitation vessel alcohol inlet, and the bottom is provided with an alcohol precipitation vessel discharge outlet. The outer wall is provided with an alcohol precipitation vessel constant temperature heat exchanger. The alcohol precipitation vessel liquid inlet is connected to the outlet of the tubular reactor through a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The alcohol precipitation vessel alcohol inlet is connected to the methanol transfer pipeline through a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The top of the crystallization vessel is provided with a liquid inlet and a gas outlet, the bottom is provided with a material outlet, and the outer wall is provided with a constant temperature heat exchanger. The gas outlet of the crystallization vessel is connected to an alcohol-water recovery pipeline through a pipeline and connected in series with a one-way valve and a vacuum pump. The top of the catalytic liquid transfer tank is provided with a transfer tank inlet and a transfer tank feed inlet, and the bottom is provided with a transfer tank outlet. The outer wall is provided with a transfer tank constant temperature heat exchanger. The transfer tank feed inlet is connected to the hexamethylenetetramine saturated liquid delivery pipeline through a pipeline and connected in series with valves, a transfer pump and an electronic flow meter. The transfer tank outlet is connected to the catalytic liquid inlet through a pipeline and connected in series with valves, a transfer pump and an electronic flow meter. The vacuum dryer has a dryer inlet at the top and a dryer outlet at the bottom. The dryer inlet is connected to the alcohol precipitation kettle outlet and the crystallization kettle inlet via pipelines and a second three-way valve, respectively. The dryer outlet is connected to the product storage tank and connected in series with valves. The recrystallization kettle is equipped with a recrystallization kettle inlet and a recrystallization kettle alcohol inlet at the top, and a recrystallization kettle outlet at the bottom. A recrystallization kettle constant temperature heat exchanger is installed on the outer wall. The recrystallization kettle inlet is connected to the recrystallization kettle outlet and the transfer tank inlet via pipelines and a third three-way valve, respectively. The recrystallization kettle alcohol inlet is connected to a methanol delivery pipeline and an alcohol-water recovery pipeline via pipelines and a fourth three-way valve, respectively. The recrystallization kettle outlet is connected to a filtration device via pipelines and connected in series with valves.

[0006] Furthermore, the tubular reactor has a shell-and-tube structure, with an inner tube diameter of 10-15 cm and an inner tube length-to-diameter ratio of 1000-2000. The outer tube is filled with a temperature-controlled medium, and the temperature is controlled by the flow of the medium.

[0007] Furthermore, the left port of the first three-way valve is connected to an ammonia gas delivery pipeline via a pipeline and is connected in series with a gas check valve, a high-temperature gas transfer pump, and a gas flow meter; the right port is connected to the inlet of a tubular reactor via a pipeline; and the upper port is connected to the outlet of a mixing vessel via a pipeline and is connected in series with a check valve, a transfer pump, and an electronic flow meter.

[0008] Furthermore, the upper port of the second three-way valve is connected to the outlet of the alcohol precipitation vessel via a pipeline and connected in series with a valve; the right port is connected to the inlet of the crystallization vessel via a pipeline and connected in series with a valve, a transfer pump, and an electronic flow meter; and the lower port is connected to the inlet of the dryer via a pipeline and connected in series with a valve.

[0009] Furthermore, the upper port of the third three-way valve is connected to the outlet of the crystallizer via a pipeline and connected in series with a valve; the right port is connected to the inlet of the transfer tank via a pipeline and connected in series with a valve, a transfer pump, and an electronic flow meter; and the lower port is connected to the inlet of the recrystallization tank via a pipeline and connected in series with a valve and a transfer pump.

[0010] Furthermore, the upper port of the fourth three-way valve is connected to the methanol delivery pipeline via a pipeline and is connected in series with the valve, the transfer pump and the electronic flow meter; the right port is connected to the alcohol-water recovery pipeline via a pipeline and is connected in series with the check valve and the vacuum pump; and the lower port is connected to the alcohol inlet of the recrystallization reactor via a pipeline.

[0011] Furthermore, the alcohol precipitation vessel, crystallization vessel, and recrystallization vessel can be connected in parallel in N units as needed, where N≥2.

[0012] Beneficial effects of this invention: The glycine production apparatus provided by this invention can be used to produce glycine by ammonolysis of chloroacetic acid.

[0013] This device produces glycine through continuous feeding and discharging, improving production efficiency and equipment utilization while reducing production costs. Simultaneously, the separation process allows for the recycling of the catalyst hexamethylenetetramine, further reducing production costs. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] In the diagram: 1. Mixing vessel; 101. Mixing vessel inlet; 102. Catalytic liquid inlet; 103. Mixing vessel outlet; 104. Mixing vessel constant temperature heat exchanger; 2. Tubular reactor; 201. Tubular reactor inlet; 202. Tubular reactor outlet; 3. Alcohol precipitation vessel; 301. Alcohol precipitation vessel inlet; 302. Alcohol precipitation vessel inlet; 303. Alcohol precipitation vessel outlet; 304. Alcohol precipitation vessel constant temperature heat exchanger; 4. Crystallization vessel; 401. Crystallization vessel inlet; 402. Crystallization vessel outlet; 403. Crystallization vessel outlet; 404. 5. Catalytic liquid transfer tank, 501. Transfer tank inlet, 502. Transfer tank outlet, 503. Transfer tank constant temperature heat exchanger, 504. Vacuum dryer, 601. Dryer inlet, 602. Dryer outlet, 7. Recrystallization kettle, 701. Recrystallization kettle inlet, 702. Recrystallization kettle alcohol inlet, 703. Recrystallization kettle outlet, 704. Recrystallization kettle constant temperature heat exchanger, 8. First three-way valve, 9. Second three-way valve, 10. Third three-way valve, 11. Fourth three-way valve. Detailed Implementation

[0016] A glycine production apparatus includes: a mixing vessel 1, a tubular reactor 2, an alcohol precipitation vessel 3, a crystallization vessel 4, a catalyst transfer tank 5, a vacuum dryer 6, and a recrystallization vessel 7. The mixing vessel 1 is provided with a mixing vessel inlet 101 and a catalyst inlet 102 at the top, a mixing vessel outlet 103 at the bottom, and a mixing vessel constant temperature heat exchanger 104 on the outer wall. The mixing vessel inlet 101 is connected to a chloroacetic acid aqueous solution delivery pipeline and connected in series with valves, a transfer pump, and an electronic flow meter. The tubular reactor 2 is provided with a tubular reactor inlet 201 and a tubular reactor outlet 202 at both ends. The tubular reactor inlet 201 is connected to the mixing vessel outlet 103 and the ammonia conveying pipeline through a pipeline and a first three-way valve 8, respectively. The top of the alcohol precipitation vessel 3 is provided with an alcohol precipitation vessel liquid inlet 301 and an alcohol precipitation vessel alcohol inlet 302, and the bottom is provided with an alcohol precipitation vessel discharge outlet 303. The outer wall is provided with an alcohol precipitation vessel constant temperature heat exchanger 304. The alcohol precipitation vessel liquid inlet 301 is connected to the tubular reactor outlet 202 through a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The alcohol precipitation vessel alcohol inlet 302 is connected to the methanol transfer pipeline through a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The top of the crystallization vessel 4 is provided with a liquid inlet 401 and a gas outlet 402, the bottom is provided with a material outlet 403, and the outer wall is provided with a constant temperature heat exchanger 404. The gas outlet 402 is connected to an alcohol-water recovery pipeline and connected in series with a one-way valve and a vacuum pump. The top of the catalytic liquid transfer tank 5 is provided with a transfer tank inlet 501 and a transfer tank feed inlet 502, and the bottom is provided with a transfer tank outlet 503. The outer wall is provided with a transfer tank constant temperature heat exchanger 504. The transfer tank feed inlet 502 is connected to the hexamethylenetetramine saturated liquid delivery pipeline through a pipeline and connected in series with valves, a transfer pump and an electronic flow meter. The transfer tank outlet 503 is connected to the catalytic liquid inlet 102 through a pipeline and connected in series with valves, a transfer pump and an electronic flow meter. The vacuum dryer 6 is provided with a dryer inlet 601 at the top and a dryer outlet 602 at the bottom. The dryer inlet 601 is connected to the alcohol precipitation kettle outlet 303 and the crystallization kettle inlet 401 respectively through pipelines and a second three-way valve 9. The dryer outlet 602 is connected to the product storage tank and connected in series with valves. The recrystallization kettle 7 is provided with a recrystallization kettle inlet 701 and a recrystallization kettle alcohol inlet 702 at the top and a recrystallization kettle outlet 703 at the bottom. The outer wall is provided with a recrystallization kettle constant temperature heat exchanger 704. The recrystallization kettle inlet 701 is connected to the crystallization kettle outlet 403 and the transfer tank inlet 501 through pipelines and a third three-way valve 10, respectively. The recrystallization kettle alcohol inlet 702 is connected to the methanol conveying pipeline and the alcohol-water recovery pipeline through pipelines and a fourth three-way valve 11, respectively. The recrystallization kettle outlet 703 is connected to a suction filter device and a valve in series through pipelines.

[0017] Furthermore, the tubular reactor 2 has a shell-and-tube structure, with an inner tube diameter of 10-15 cm and an inner tube length-to-diameter ratio of 1000-2000. The outer tube is filled with a temperature-controlled medium, and the temperature is controlled by the flow of the medium.

[0018] Furthermore, the left port of the first three-way valve 8 is connected to an ammonia gas delivery pipeline via a pipeline and is connected in series with a gas check valve, a high-temperature gas transfer pump, and a gas flow meter; the right port is connected to the inlet 201 of the tubular reactor via a pipeline; and the upper port is connected to the outlet 103 of the mixing vessel via a pipeline and is connected in series with a check valve, a transfer pump, and an electronic flow meter.

[0019] Furthermore, the upper port of the second three-way valve 9 is connected to the outlet 303 of the alcohol precipitation vessel via a pipeline and is connected in series with a valve; the right port is connected to the inlet 401 of the crystallization vessel via a pipeline and is connected in series with a valve, a transfer pump and an electronic flow meter; and the lower port is connected to the inlet 601 of the dryer via a pipeline and is connected in series with a valve.

[0020] Furthermore, the upper port of the third three-way valve 10 is connected to the outlet 403 of the crystallizer via a pipeline and is connected in series with a valve; the right port is connected to the inlet 501 of the transfer tank via a pipeline and is connected in series with a valve, a transfer pump and an electronic flow meter; and the lower port is connected to the inlet 701 of the recrystallization tank via a pipeline and is connected in series with a valve and a transfer pump.

[0021] Furthermore, the upper port of the fourth three-way valve 11 is connected to the methanol delivery pipeline via a pipeline and is connected in series with a valve, a transfer pump and an electronic flow meter; the right port is connected to the alcohol-water recovery pipeline via a pipeline and is connected in series with a check valve and a vacuum pump; and the lower port is connected to the recrystallization kettle inlet 702 via a pipeline.

[0022] Furthermore, the alcohol precipitation vessel 3, crystallization vessel 4, and recrystallization vessel 7 can be connected in parallel in N units as needed, where N≥2.

[0023] The above description is a preferred embodiment of the present utility model. For those skilled in the art, any changes, modifications, substitutions and variations made to the implementation methods without departing from the principles and spirit of the present utility model, based on the teachings of the present utility model, still fall within the protection scope of the present utility model.

Claims

1. A glycine production apparatus, comprising: The mixing vessel (1), tubular reactor (2), alcohol precipitation vessel (3), crystallization vessel (4), catalytic liquid transfer tank (5), vacuum dryer (6) and recrystallization vessel (7) are characterized in that the mixing vessel (1) is provided with a mixing vessel inlet (101) and a catalytic liquid inlet (102) at the top, a mixing vessel outlet (103) at the bottom, and a mixing vessel constant temperature heat exchanger (104) on the outer wall. The mixing vessel inlet (101) is connected to a chloroacetic acid aqueous solution delivery pipeline and connected in series with valves, transfer pumps and electronic flow meters. The tubular reactor (2) is provided with a tubular reactor inlet (201) and a tubular reactor outlet (202) at both ends. The tubular reactor inlet (201) is connected to the mixing vessel outlet (103) and the ammonia conveying pipeline through a pipeline and a first three-way valve (8). The top of the alcohol precipitation vessel (3) is provided with an alcohol precipitation vessel liquid inlet (301) and an alcohol precipitation vessel alcohol inlet (302), and the bottom is provided with an alcohol precipitation vessel discharge outlet (303). The outer wall is provided with an alcohol precipitation vessel constant temperature heat exchanger (304). The alcohol precipitation vessel liquid inlet (301) is connected to the tubular reactor outlet (202) through a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The alcohol precipitation vessel alcohol inlet (302) is connected to a methanol transfer pipeline through a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The top of the crystallization vessel (4) is provided with a liquid inlet (401) and a gas outlet (402), the bottom is provided with a material outlet (403), and the outer wall is provided with a constant temperature heat exchanger (404). The gas outlet (402) of the crystallization vessel is connected to the alcohol-water recovery pipeline through a pipeline and connected in series with a one-way valve and a vacuum pump. The top of the catalytic liquid transfer tank (5) is provided with a transfer tank inlet (501) and a transfer tank feed inlet (502), and the bottom is provided with a transfer tank outlet (503). The outer wall is provided with a transfer tank constant temperature heat exchanger (504). The transfer tank feed inlet (502) is connected to the hexamethylenetetramine saturated liquid delivery pipeline through a pipeline and connected in series with valves, a transfer pump and an electronic flow meter. The transfer tank outlet (503) is connected to the catalytic liquid inlet (102) through a pipeline and connected in series with valves, a transfer pump and an electronic flow meter. The vacuum dryer (6) is provided with a dryer inlet (601) at the top and a dryer outlet (602) at the bottom. The dryer inlet (601) is connected to the alcohol precipitation kettle outlet (303) and the crystallization kettle inlet (401) respectively through pipelines and a second three-way valve (9). The dryer outlet (602) is connected to the product storage tank and connected in series with valves. The recrystallization kettle (7) is provided with a recrystallization kettle inlet (701) and a recrystallization kettle alcohol inlet (702) at the top and a recrystallization kettle outlet (703) at the bottom. The outer wall is provided with a recrystallization kettle constant temperature heat exchanger (704). The recrystallization kettle inlet (701) is connected to the crystallization kettle outlet (403) and the transfer tank inlet (501) through pipelines and a third three-way valve (10). The recrystallization kettle alcohol inlet (702) is connected to the methanol conveying pipeline and the alcohol-water recovery pipeline through pipelines and a fourth three-way valve (11). The recrystallization kettle outlet (703) is connected to the filtration device and valves in series through pipelines.

2. The glycine production apparatus according to claim 1, characterized in that, The tubular reactor (2) has a shell-and-tube structure with an inner tube diameter of 10-15 cm and an inner tube length-to-diameter ratio of 1000-2000. The outer tube is filled with a temperature-controlled medium, and the temperature is controlled by the flow of the medium.

3. The glycine production apparatus according to claim 1, characterized in that, The left port of the first three-way valve (8) is connected to the ammonia gas delivery pipeline via a pipeline and connected in series with a gas check valve, a high-temperature gas transfer pump and a gas flow meter. The right port is connected to the inlet (201) of the tubular reactor via a pipeline. The upper port is connected to the outlet (103) of the mixing vessel via a pipeline and connected in series with a check valve, a transfer pump and an electronic flow meter.

4. The glycine production apparatus according to claim 1, characterized in that, The upper port of the second three-way valve (9) is connected to the outlet (303) of the alcohol precipitation vessel via a pipeline and connected in series with a valve. The right port is connected to the inlet (401) of the crystallization vessel via a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The lower port is connected to the inlet (601) of the dryer via a pipeline and connected in series with a valve.

5. A glycine production apparatus according to claim 1, characterized in that, The upper port of the third three-way valve (10) is connected to the outlet (403) of the crystallizer via a pipeline and connected in series with a valve. The right port is connected to the inlet (501) of the transfer tank via a pipeline and connected in series with a valve, a transfer pump and an electronic flow meter. The lower port is connected to the inlet (701) of the recrystallization tank via a pipeline and connected in series with a valve and a transfer pump.

6. The glycine production apparatus according to claim 1, characterized in that, The upper port of the fourth three-way valve (11) is connected to the methanol delivery pipeline via a pipeline and in series with the valve, the transfer pump and the electronic flow meter. The right port is connected to the alcohol-water recovery pipeline via a pipeline and in series with the check valve and the vacuum pump. The lower port is connected to the recrystallization kettle inlet (702) via a pipeline.

7. A glycine production apparatus according to claim 1, characterized in that, The alcohol precipitation vessel (3), crystallization vessel (4) and recrystallization vessel (7) can be connected in parallel in N units as needed, where N≥2.

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