Purification system for glycine containing impurities

Abstract

The utility model discloses a purification system for glycine containing impurities, which belongs to the technical field of glycine purification and comprises a dissolution treatment kettle and a crystallization kettle, stirring mechanisms are arranged on both the dissolution treatment kettle and the crystallization kettle, a water inlet pipe, a reagent inlet pipe and a first discharge pipe are arranged on the dissolution treatment kettle, a transfer pump and a plate-and-frame filter press are arranged on the first discharge pipe, and a second discharge pipe is arranged on the second discharge pipe. The plate-and-frame filter press is connected with the crystallization kettle through a material transfer pipe; a second discharge pipe is arranged at the lower end of the crystallization kettle. The method comprises the following steps: putting glycine into a dissolving treatment kettle, settling by using water, a decolorizing agent and an adsorbent, separating the decolorizing agent and the adsorbent by using a plate-and-frame filter press while the solution is hot, enabling filtrate to flow into a crystallization kettle for cooling crystallization, discharging the crystallized solution into a separation and drying process by using a second discharge pipe, and drying a crystal substance to obtain a glycine product with the content of more than 99%, the mother liquor is continuously used for preparing a supersaturated solution.

Description

Technical Field

[0001] Technical Field+

[0002] The utility model belongs to the technical field of glycine purification, and in particular relates to a purification system for glycine containing impurities. Background Art

[0003] The conventional process for glycine production in my country is the chloroacetic acid ammonolysis method. However, with the strengthening of environmental awareness in recent years, the environmental problems caused by the chloroacetic acid ammonolysis method have become increasingly prominent, and the process of producing glycine using hydroxyacetonitrile as raw material has received more and more attention. There are two routes for producing glycine using hydroxyacetonitrile as raw material, one is the hydroxyacetonitrile amination method, and the other is the Hein method. The hydroxyacetonitrile amination method is to use hydroxyacetonitrile and ammonia as raw materials to undergo an amination reaction in a water system to obtain aminoacetonitrile, and then alkaline hydrolysis and acidification to obtain glycine. The product of this route contains iminodiacetic acid and inorganic salts, and the product purification and separation are difficult, the product quality is poor, and the production cost is high. The Hein method is to synthesize glycine by reacting hydroxyacetonitrile with ammonia and carbon dioxide (or ammonium bicarbonate) in a water system under high temperature and high pressure.

[0004] The principle of Hein's method for synthesizing glycine is as follows:

[0005]

[0006]

[0007] The hydantoin process for producing glycine is to first synthesize hydantoin acid, hydantoin amide and other intermediates from hydroxyacetonitrile with a carbon source (such as carbon dioxide) and an ammonia source (such as ammonia) in a water system, and then hydrolyze to obtain glycine, and release ammonia and carbon dioxide. Since ammonia and carbon dioxide can circulate in the system, the hydantoin process is theoretically the cleanest glycine production process.

[0008] In the glycine production process, due to the corrosion of the feed pipeline and reaction device due to long-term use, and the uneven temperature during the drying process, which causes local high temperature, glycine is prone to coking and containing mechanical impurities (dust, fiber, etc.). It is difficult to use conventional filtration, centrifugation, adsorption and other methods to treat glycine containing multiple impurities at the same time. Utility Model Content

[0009] The utility model aims to solve the problems of the prior art and provides a purification system for glycine containing impurities. The glycine is placed in a dissolution treatment kettle, and then water, a decolorizing agent and an adsorbent are passed through the kettle. After sedimentation, the decolorizing agent and the adsorbent are separated while hot through a plate and frame filter press. The filtrate flows into a crystallization kettle for cooling and crystallization. After crystallization, the filtrate is discharged into a separation and drying process through a second discharge pipe. After the crystals are dried, a glycine product with a content of more than 99% is obtained, and the mother liquor is continuously used for preparing a supersaturated solution.

[0010] The utility model is realized by the following technical solutions:

[0011] A purification system for glycine containing impurities comprises a dissolution treatment kettle and a crystallization kettle, wherein the dissolution treatment kettle and the crystallization kettle are both provided with a stirring mechanism, the dissolution treatment kettle is provided with a water inlet pipe, a reagent inlet pipe and a first discharge pipe, the first discharge pipe is provided with a transfer pump and a plate and frame filter press, the plate and frame filter press is connected to the crystallization kettle via a transfer pipe, and a second discharge pipe is provided at the lower end of the crystallization kettle.

[0012] Preferably, the stirring mechanism comprises a stirring motor, a stirring shaft and a stirring paddle, the output end of the stirring motor is connected to the stirring shaft, and the stirring paddle is arranged on the stirring shaft.

[0013] Preferably, the dissolution treatment kettle is provided with a first heat exchange jacket.

[0014] Preferably, the first heat exchange jacket is provided with a steam inlet pipe and a condensed water outlet pipe.

[0015] Preferably, a steam inlet valve is provided on the steam inlet pipe.

[0016] Preferably, a second heat exchange jacket is provided on the crystallization kettle.

[0017] Preferably, the second heat exchange jacket is provided with a circulating water inlet pipe and a circulating water outlet pipe.

[0018] Preferably, a circulating water inlet valve is provided on the circulating water inlet pipe.

[0019] Preferably, the dissolution treatment kettle and the crystallization kettle are respectively provided with a first thermometer and a second thermometer.

[0020] Preferably, both the dissolution treatment kettle and the crystallization kettle are provided with tail gas emission pipes.

[0021] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0022] 1. The utility model provides a purification system for glycine containing impurities, wherein glycine is placed in a dissolution treatment kettle, and then passed through water, a decolorant and an adsorbent, and after sedimentation, the decolorant and the adsorbent are separated while hot through a plate and frame filter press, and the filtrate flows into a crystallization kettle for cooling and crystallization, and after crystallization, it is discharged into a separation and drying process through a second discharge pipe, and the separation and drying process adopts conventional means, such as: using a centrifuge to separate the crystal liquid, and the wet glycine product separated by the centrifuge is dried by an air flow drying system to obtain a glycine finished product; after the crystals are dried, a glycine product with a content of more than 99% is obtained, and the mother liquor is further used to prepare a supersaturated solution.

[0023] 2. The utility model provides a purification system for glycine containing impurities. The first thermometer detects the temperature in the dissolution treatment kettle, and the temperature in the dissolution treatment kettle is adjusted by adjusting the opening of the steam inlet valve to meet the dissolution, decolorization and adsorption requirements of the glycine in the dissolution treatment kettle; it can also be combined with a DCS to automatically control the opening of the steam inlet valve.

[0024] 3. The utility model provides a purification system for glycine containing impurities. The second thermometer detects the temperature in the crystallization kettle. The temperature in the crystallization kettle is adjusted by adjusting the opening of the circulating water inlet valve to meet the crystallization requirements in the crystallization kettle. It can also be combined with DCS to automatically control the opening of the circulating water inlet valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the utility model;

[0026] Wherein: 100, dissolution treatment kettle; 110, water inlet pipe; 120, reagent inlet pipe; 130, first discharge pipe; 140, first heat exchange jacket; 141, steam inlet pipe; 142, condensed water outlet pipe; 143, steam inlet valve; 150, first thermometer; 200, crystallization kettle; 210, second discharge pipe; 220, second heat exchange jacket; 221, circulating water inlet pipe; 222, circulating water outlet pipe; 223, circulating water inlet valve; 230, second thermometer; 300, stirring mechanism; 310, stirring motor; 320, stirring shaft; 330, stirring paddle; 400, transfer pump; 500, plate and frame filter press; 600, transfer pipe; 700, exhaust pipe. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the embodiments, but the implementation manner of the present invention is not limited thereto.

[0028] Example 1

[0029] like Figure 1 As shown, the present embodiment provides a purification system for glycine containing impurities, including a dissolution treatment kettle 100 and a crystallization kettle 200, wherein the dissolution treatment kettle 100 and the crystallization kettle 200 are both provided with a stirring mechanism 300, the dissolution treatment kettle 100 is provided with a water inlet pipe 110, a reagent inlet pipe 120 and a first discharge pipe 130, the first discharge pipe is provided with a transfer pump 400 and a plate and frame filter press 500, the plate and frame filter press 500 is connected to the crystallization kettle 200 via a transfer pipe 600, and a second discharge pipe 210 is provided at the lower end of the crystallization kettle 200.

[0030] Glycine is placed in a dissolution treatment kettle 100, and then passed through water, a decolorant and an adsorbent. After sedimentation, the decolorant and the adsorbent are separated while hot through a plate and frame filter press 500. The filtrate flows into a crystallization kettle 200 for cooling and crystallization. After crystallization, it is discharged into a separation and drying process through a second discharge pipe 210. The separation and drying process adopts conventional means, such as: using a centrifuge to separate the crystal liquid, and the wet glycine product separated by the centrifuge is dried by an air flow drying system to obtain a glycine finished product; after the crystals are dried, a glycine product with a content of more than 99% is obtained, and the mother liquor is further used to prepare a supersaturated solution.

[0031] Example 2

[0032] The difference between this embodiment and embodiment 1 is that the stirring mechanism 300 includes a stirring motor 310 , a stirring shaft 320 and a stirring paddle 330 , the output end of the stirring motor 310 is connected to the stirring shaft 320 , and the stirring paddle 330 is arranged on the stirring shaft 320 .

[0033] Wherein, the dissolution treatment kettle 100 is provided with a first heat exchange jacket 140 .

[0034] The first heat exchange jacket 140 is provided with a steam inlet pipe 141 and a condensed water outlet pipe 142 .

[0035] The steam inlet pipe 141 is provided with a steam inlet valve 143. The first thermometer 150 detects the temperature in the dissolution treatment kettle 100, and adjusts the temperature in the dissolution treatment kettle 100 by adjusting the opening of the steam inlet valve 143 to meet the requirements of dissolution, decolorization and adsorption of glycine in the dissolution treatment kettle 100; it can also be combined with DCS to automatically control the opening of the steam inlet valve 143.

[0036] Wherein, the crystallization kettle 200 is provided with a second heat exchange jacket 220 .

[0037] Wherein, the second heat exchange jacket 220 is provided with a circulating water inlet pipe 221 and a circulating water outlet pipe 222 .

[0038] The circulating water inlet pipe 221 is provided with a circulating water inlet valve 223. The second thermometer 230 detects the temperature in the crystallization kettle 200, and adjusts the temperature in the crystallization kettle 200 by adjusting the opening of the circulating water inlet valve 223 to meet the crystallization requirements in the crystallization kettle 200; it can also be combined with DCS to automatically control the opening of the circulating water inlet valve 223.

[0039] The dissolution treatment kettle 100 and the crystallization kettle 200 are respectively provided with a first thermometer 150 and a second thermometer 230 .

[0040] The dissolution treatment kettle 100 and the crystallization kettle 200 are both provided with an exhaust gas discharge pipe 700. The exhaust gas discharge pipe 700 is connected to the exhaust gas main pipe.

[0041] When the utility model is used, the impurity-containing material is prepared into a supersaturated solution (concentration range 18%~38%, optimal 33.5%) at a certain temperature (temperature range 20~90℃, optimal 70℃), and then a certain amount (concentration range 0.1‰~5%, optimal 0.5‰) of decolorizing agent (coconut shell charcoal, activated carbon, etc.) is added to carry out decolorization treatment at a certain temperature (temperature range 220~90℃, optimal 70℃) for a certain time (0.5~5h, optimal 1.5h), and then a certain amount (concentration range 0.01‰~5‰, optimal 0.1‰) of adsorbent (polyaluminium chloride, polyacrylamide, etc.) and stirred at a certain temperature (temperature range 20~90℃, optimal 70℃) for a certain time (time range 0.5~5h, optimal 0.5h), separate the decolorant and adsorbent while hot after sedimentation, the filtrate flows into the crystallization kettle 200 for cooling and crystallization (crystallization temperature is 0~40℃, optimal 10℃), and after crystallization, it is discharged into the separation and drying process through the second discharge pipe 210. After drying the crystals, a glycine product with a content of more than 99% is obtained, and the mother liquor is further used to prepare a supersaturated solution.

[0042] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A purification system for glycine containing impurities, characterized in that: The invention comprises a dissolution treatment kettle (100) and a crystallization kettle (200), wherein the dissolution treatment kettle (100) and the crystallization kettle (200) are both provided with a stirring mechanism (300), the dissolution treatment kettle (100) is provided with a water inlet pipe (110), a reagent inlet pipe (120) and a first discharge pipe (130), the first discharge pipe is provided with a transfer pump (400) and a plate-frame filter press (500), the plate-frame filter press (500) is connected to the crystallization kettle (200) via a transfer pipe (600), and a second discharge pipe (210) is provided at the lower end of the crystallization kettle (200).

2. A purification system for glycine containing impurities according to claim 1, characterized in that: The stirring mechanism (300) comprises a stirring motor (310), a stirring shaft (320) and a stirring paddle (330); the output end of the stirring motor (310) is connected to the stirring shaft (320), and the stirring paddle (330) is arranged on the stirring shaft (320).

3. The system for purifying glycine containing impurities according to claim 1, characterized in that: The dissolution treatment kettle (100) is provided with a first heat exchange jacket (140).

4. A purification system for glycine containing impurities according to claim 3, characterized in that: The first heat exchange jacket (140) is provided with a steam inlet pipe (141) and a condensed water outlet pipe (142).

5. A purification system for glycine containing impurities according to claim 4, characterized in that: The steam inlet pipe (141) is provided with a steam inlet valve (143).

6. The system for purifying glycine containing impurities according to claim 1, characterized in that: The crystallization kettle (200) is provided with a second heat exchange jacket (220).

7. A purification system for glycine containing impurities according to claim 6, characterized in that: The second heat exchange jacket (220) is provided with a circulating water inlet pipe (221) and a circulating water outlet pipe (222).

8. A purification system for glycine containing impurities according to claim 7, characterized in that: The circulating water inlet pipe (221) is provided with a circulating water inlet valve (223).

9. The system for purifying glycine containing impurities according to claim 1, characterized in that: The dissolution treatment kettle (100) and the crystallization kettle (200) are respectively provided with a first thermometer (150) and a second thermometer (230).

10. The system for purifying glycine containing impurities according to claim 1, characterized in that: The dissolution treatment kettle (100) and the crystallization kettle (200) are both provided with an exhaust gas discharge pipe (700).

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