CN115141095A - Process for re-melting, purifying and recrystallizing adipic acid - Google Patents
Process for re-melting, purifying and recrystallizing adipic acid Download PDFInfo
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- CN115141095A CN115141095A CN202210782195.4A CN202210782195A CN115141095A CN 115141095 A CN115141095 A CN 115141095A CN 202210782195 A CN202210782195 A CN 202210782195A CN 115141095 A CN115141095 A CN 115141095A
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- C07C51/42—Separation; Purification; Stabilisation; Use of additives
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Abstract
The invention relates to the technical field of adipic acid crystallization, in particular to a process for re-melting, purifying and recrystallizing adipic acid. Which comprises the following steps: discharging the primary crystallization liquid, feeding the discharged primary crystallization liquid into a heat recovery barrel for re-melting, and feeding the heated primary crystallization liquid into a cooling crystallizer for cooling and crystallization to form a circulating crystallization liquid; starting a circulating pump, refluxing the circulating crystallization liquid to a heat recovery barrel for heat recovery and re-melting, and then, entering a cooling crystallization chamber again for crystallization to prepare adipic acid crystal slurry; in the adipic acid re-melting purification and recrystallization process, circulating crystallization liquid is circulated between a cooling crystallizer and a heat regeneration barrel, so that crystals in the circulating crystallization liquid can be heated and re-melted, the grain size of the crystals is reduced after re-melting, nucleation impurities wrapped in the crystals before re-melting are separated, and the crystallization liquid is crystallized on the basis of the crystals with small grain size when re-crystallizing, so that the adipic acid crystals with uniform grain size and high purity can be prepared.
Description
Technical Field
The invention relates to the technical field of adipic acid crystallization, in particular to a process for re-melting, purifying and recrystallizing adipic acid.
Background
Crystallization refers to a separation process of separating out solid crystals from solution, steam or melt, and a crystallization process is an important operation unit in a chemical process and is also an important link for completing the generation of chemical products. Crystallization is achieved by lowering the temperature or removing part of the solvent. In the formation, this is achieved mainly by crystallizers, which yield a crystalline product suitable for the requirements.
In the existing adipic acid crystallization process, concentrated adipic acid stock solution is usually directly fed into a crystallizer for flash evaporation crystallization, but the crystallization mode has the defects of uneven granularity and lower purity of the produced crystal product, so a novel adipic acid re-melting, purifying and recrystallizing process is needed to improve the defects of the prior art.
Disclosure of Invention
The invention aims to provide a process for re-melting, purifying and recrystallizing adipic acid so as to solve the problems in the background technology.
In order to achieve the purpose, the invention provides a process for re-melting, purifying and recrystallizing adipic acid, which comprises the following steps:
s1, adding an adipic acid stock solution into a stock solution barrel for later use;
s2, enabling the adipic acid stock solution to work through a stock solution barrel discharge pump, and introducing the adipic acid stock solution into a preheating barrel to heat;
s3, starting a discharge pump of the preheating barrel, introducing the stock solution into an evaporative crystallizer, forming small-particle crystals in the adipic acid stock solution by the work of the evaporative crystallizer, and discharging the crystals by a discharge pump of the evaporative crystallizer;
s4, discharging the primary crystallization liquid, then feeding the discharged primary crystallization liquid into a heat recovery barrel to increase the liquid temperature, when the temperature of the primary crystallization liquid rises, enabling the crystals to re-melt, then starting a discharge pump of the heat recovery barrel to feed the heated primary crystallization liquid into a cooling crystallizer, and performing rapid cooling crystallization through a crystallization chamber of the cooling crystallizer to form a circulating crystallization liquid after crystallization;
s5, starting a circulating pump, discharging the circulating crystallization liquid from the cooling crystallizer, refluxing the circulating crystallization liquid to a heat recovery barrel for heat recovery and re-melting, and then starting a heat recovery barrel discharge pump to enable the re-melted circulating crystallization liquid to enter a cooling crystallization chamber again for crystallization, so that adipic acid crystal slurry can be prepared;
and S6, putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
As a further improvement of the technical scheme, in the S1, the concentration of the adipic acid stock solution is 18-23%.
As a further improvement of the technical scheme, in the S2, the adipic acid stock solution is heated to 40-45 ℃ for not more than 3mim.
As a further improvement of the technical scheme, in S2, the preheating barrel needs to be heated up in advance before the adipic acid stock solution enters, and is stirred by the stirring device in the heating process to drive the adipic acid stock solution to disperse inside.
As a further improvement of the technical scheme, in the S3, the adipic acid stock solution is heated to 50-55 ℃ and the concentration of the stock solution is increased to 48-52%.
As a further improvement of the technical scheme, in S4, the temperature of the heat-returning barrel is raised to 50-55 ℃ in advance, and the primary crystallization liquid enters the heat-returning barrel for the first time and stays for 30-40min to raise the liquid temperature.
As a further improvement of the technical scheme, in S5, circulating crystallization liquid flows back to a heat-returning barrel, and is retained for 20-30min for heat-returning and re-melting under the condition that the temperature is 50-55 ℃.
As a further improvement of the technical scheme, in the S5, the circulating step is performed for 6-7h for crystallization.
Compared with the prior art, the invention has the beneficial effects that:
1. in the adipic acid re-melting purification and recrystallization process, circulating crystallization liquid is circulated between a cooling crystallizer and a heat regeneration barrel, so that crystals in the circulating crystallization liquid can be heated and re-melted, the grain size of the crystals is reduced after re-melting, nucleation impurities wrapped in the crystals before re-melting are separated, and the crystallization liquid is crystallized on the basis of the crystals with small grain size when re-crystallizing, so that the adipic acid crystals with uniform grain size and high purity can be prepared.
2. In the adipic acid re-melting, purifying and recrystallizing process, the adipic acid stock solution enters a preheating barrel, and the adipic acid stock solution is dispersed in the preheating barrel in a heating and stirring manner, so that the large-area dispersive crystallization of the stock solution is facilitated, and the crystal size is uniform.
Drawings
FIG. 1 is an overall flow diagram of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The technological process of adipic acid re-melting purification recrystallization of the invention is shown in fig. 1, and in order to embody the different technological processes, the process of adipic acid re-melting purification recrystallization of the invention is divided into the following specific examples for explanation
Example 1
The embodiment provides a process for re-melting, purifying and recrystallizing adipic acid, which comprises the following steps:
1. adding the adipic acid stock solution with the concentration of 18% into a stock solution barrel for later use.
2. Adipic acid stock solution is guided into a preheating barrel through a stock solution barrel discharge pump to work, the temperature is raised to 40 ℃, the temperature rise time is not more than 3 mm, the preheating barrel needs to be raised in advance before the adipic acid stock solution enters, the time consumed by the temperature rise of the stock solution is reduced, meanwhile, the overlong temperature rise time of the stock solution is avoided, part of liquid is evaporated to influence the subsequent work, the mixing is carried out through a mixing device in the heating process, the internal dispersion of the adipic acid stock solution is driven, the large-area crystallization of the dispersibility of the stock solution is facilitated, and the crystallization granularity is uniform.
3. Starting a discharge pump of a preheating barrel, guiding stock solution into an evaporative crystallizer, heating the adipic acid stock solution to 50 ℃ through working of a heating chamber in the evaporative crystallizer, then feeding the adipic acid stock solution into a crystallization chamber in the evaporative crystallizer to boil the stock solution, gradually increasing the concentration of the stock solution to 48%, depositing part of solute on the surface of suspended crystal grains to form small-particle crystals, discharging the small-particle crystals through a discharge pump of the evaporative crystallizer, and reducing the temperature of the primary crystal liquid containing the small-particle crystals to 9 ℃ during discharging.
4. And (3) discharging the primary crystallization liquid and then feeding the discharged primary crystallization liquid into a heat recovery barrel, raising the temperature of the heat recovery barrel to 50 ℃ in advance, retaining the primary crystallization liquid in the heat recovery barrel for 30min to improve the liquid temperature, when the temperature of the primary crystallization liquid rises, re-melting the crystals, then starting a discharge pump of the heat recovery barrel to feed the heated primary crystallization liquid into a cooling crystallizer, and rapidly cooling and crystallizing the crystals in a crystallization chamber of the cooling crystallizer to form a circulating crystallization liquid after crystallization.
5. And starting a circulating pump, discharging the circulating crystallization liquid from the cooling crystallizer, refluxing the circulating crystallization liquid to a heat recovery barrel, staying for 20min at the temperature of 50 ℃, performing heat recovery and re-melting, starting a heat recovery barrel discharge pump, feeding the re-melted circulating crystallization liquid into a cooling crystallization chamber again for crystallization, and performing the circulating step for 6h to obtain the adipic acid crystal slurry.
6. And (3) putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
Example 2
The embodiment provides a process for re-melting, purifying and recrystallizing adipic acid, which comprises the following steps:
1. adding the adipic acid stock solution with the concentration of 20% into a stock solution barrel for later use.
2. Adipic acid stock solution is guided into a preheating barrel through a stock solution barrel discharge pump to work, the temperature is raised to 42 ℃, the temperature rise time is not more than 3 mm, the preheating barrel needs to be raised in advance before the adipic acid stock solution enters, the time consumed by the temperature rise of the stock solution is reduced, meanwhile, the overlong temperature rise time of the stock solution is avoided, part of liquid is evaporated to influence the subsequent work, the mixing is carried out through a mixing device in the heating process, the internal dispersion of the adipic acid stock solution is driven, the large-area crystallization of the dispersibility of the stock solution is facilitated, and the crystallization granularity is uniform.
3. Opening a preheating barrel discharge pump, guiding stock solution into an evaporative crystallizer, heating the adipic acid stock solution to 52 ℃ through the work of a heating chamber in the evaporative crystallizer, then feeding the adipic acid stock solution into a crystallization chamber in the evaporative crystallizer to boil the stock solution, gradually increasing the concentration of the stock solution to 49%, depositing partial solute on the surface of suspended crystal grains to form small-particle crystals, discharging the small-particle crystals through a discharge pump of the evaporative crystallizer, and reducing the temperature of the primary crystal liquid containing the small-particle crystals to 9 ℃ during discharging.
4. And (3) discharging the primary crystallization liquid and then feeding the discharged primary crystallization liquid into a heat recovery barrel, raising the temperature of the heat recovery barrel to 52 ℃ in advance, retaining the primary crystallization liquid in the heat recovery barrel for 30min to improve the liquid temperature, when the temperature of the primary crystallization liquid rises, re-melting the crystals, then starting a discharge pump of the heat recovery barrel to feed the heated primary crystallization liquid into a cooling crystallizer, and rapidly cooling and crystallizing the crystals in a crystallization chamber of the cooling crystallizer to form a circulating crystallization liquid after crystallization.
5. And starting a circulating pump, discharging the circulating crystallization liquid from the cooling crystallizer, refluxing the circulating crystallization liquid to a heat recovery barrel, staying for 24min for heat recovery and re-melting at the temperature of 52 ℃, then starting a heat recovery barrel discharge pump to re-enter the re-melted circulating crystallization liquid into a cooling crystallization chamber for crystallization, and performing the circulating step for 6h to obtain the adipic acid crystal slurry.
6. And (3) putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
Example 3
The embodiment provides a process for re-melting, purifying and recrystallizing adipic acid, which comprises the following steps:
1. adding the adipic acid stock solution with the concentration of 22% into a stock solution barrel for later use.
2. Adipic acid stock solution is guided into a preheating barrel through a stock solution barrel discharge pump to work, the temperature is raised to 44 ℃, the temperature rise time is not more than 3 mm, the preheating barrel needs to be raised in advance before the adipic acid stock solution enters, the time consumed by the temperature rise of the stock solution is reduced, meanwhile, the problem that the subsequent work is influenced by evaporation of part of the liquid due to overlong temperature rise time of the stock solution is avoided, the adipic acid stock solution is stirred through a stirring device in the heating process, the internal dispersion of the adipic acid stock solution is driven, the large-area crystallization of the dispersion of the stock solution is facilitated, and the crystallization granularity is uniform.
3. Starting a preheating barrel discharge pump, introducing the stock solution into an evaporative crystallizer, heating the adipic acid stock solution to 54 ℃ through the work of a heating chamber in the evaporative crystallizer, then feeding the adipic acid stock solution into a crystallization chamber in the evaporative crystallizer to boil the stock solution, gradually increasing the concentration of the stock solution to 50%, depositing part of solute on the surface of suspended crystal grains to form small-particle crystals, discharging the small-particle crystals through a discharge pump of the evaporative crystallizer, and reducing the temperature of the primary crystal liquid containing the small-particle crystals to 10 ℃ during discharging.
4. And (3) feeding the discharged primary crystallization liquid into a heat recovery barrel, raising the temperature of the heat recovery barrel to 54 ℃ in advance, retaining the primary crystallization liquid in the heat recovery barrel for 35min to improve the liquid temperature, when the temperature of the primary crystallization liquid rises, re-melting the crystals, then starting a discharge pump of the heat recovery barrel to feed the raised primary crystallization liquid into a cooling crystallizer, and performing rapid cooling crystallization through a crystallization chamber of the cooling crystallizer to form a circulating crystallization liquid after crystallization.
5. And starting a circulating pump, discharging the circulating crystallization liquid from the cooling crystallizer, refluxing the circulating crystallization liquid to a heat recovery barrel, staying for 28min for heat recovery and re-melting at the temperature of 54 ℃, then starting a heat recovery barrel discharge pump to re-enter the re-melted circulating crystallization liquid into a cooling crystallization chamber for crystallization, and performing the circulating step for 7h to obtain the adipic acid crystal slurry.
6. And (3) putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
Example 4
The embodiment provides a process for re-melting, purifying and recrystallizing adipic acid, which comprises the following steps:
1. adding the adipic acid stock solution with the concentration of 23% into a stock solution barrel for later use.
2. Adipic acid stock solution is guided into a preheating barrel through a stock solution barrel discharge pump to work, the temperature is raised to 45 ℃, the temperature rise time is not more than 3 mm, the preheating barrel needs to be raised in advance before the adipic acid stock solution enters, the time consumed by the temperature rise of the stock solution is reduced, meanwhile, the overlong temperature rise time of the stock solution is avoided, part of liquid is evaporated to influence the subsequent work, the mixing is carried out through a mixing device in the heating process, the internal dispersion of the adipic acid stock solution is driven, the large-area crystallization of the dispersibility of the stock solution is facilitated, and the crystallization granularity is uniform.
3. Starting a discharge pump of a preheating barrel, introducing the stock solution into an evaporative crystallizer, heating the adipic acid stock solution to 55 ℃ through the work of a heating chamber in the evaporative crystallizer, then introducing the adipic acid stock solution into a crystallization chamber in the evaporative crystallizer to boil the stock solution, gradually increasing the concentration of the stock solution to 52%, depositing part of solute on the surface of suspended crystal grains to form small-particle crystals, discharging the small-particle crystals through a discharge pump of the evaporative crystallizer, and reducing the temperature of the primary crystal liquid containing the small-particle crystals to 11 ℃ during discharging.
4. And (3) discharging the primary crystallization liquid and then feeding the discharged primary crystallization liquid into a heat recovery barrel, raising the temperature of the heat recovery barrel to 55 ℃ in advance, retaining the primary crystallization liquid in the heat recovery barrel for 40min for the first time to improve the liquid temperature, when the temperature of the primary crystallization liquid rises, re-melting the crystals, then starting a discharge pump of the heat recovery barrel to feed the heated primary crystallization liquid into a cooling crystallizer, and rapidly cooling and crystallizing the crystals in a crystallization chamber of the cooling crystallizer to form a circulating crystallization liquid after crystallization.
5. And starting a circulating pump, discharging the circulating crystallization liquid from the cooling crystallizer, refluxing the circulating crystallization liquid to a heat recovery barrel, staying for 30min at the temperature of 55 ℃, performing heat recovery and re-melting, starting a heat recovery barrel discharge pump, feeding the re-melted circulating crystallization liquid into a cooling crystallization chamber again for crystallization, and performing the circulating step for 7h to obtain the adipic acid crystal slurry.
6. And (3) putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
Specific parameters for examples 1-4 above are shown in Table 1:
TABLE 1
In the above embodiments 1 to 4, the working principle of the evaporative crystallizer is to evaporate part of the solvent to achieve the solution concentration;
the working principle of the adopted cooling crystallizer is that the temperature of the material is reduced, so that the material generates supersaturation degree, and the material is finally promoted to crystallize;
the working principle of the adopted regenerative barrel is that the material entering the barrel is dissolved in a heating mode.
In order to verify that the adipic acid crystals produced by the adipic acid re-melting, purifying and recrystallizing process provided by the invention have higher purity, the invention also provides the following comparative examples for specific description.
Comparative example 1
The comparative example of the invention adopts the adipic acid re-melting purification recrystallization process provided by the embodiment 1, only removes the circulating step between the heat recovery barrel and the cooling crystallizer, adopts the mode of directly cooling and crystallizing the cooling crystallizer, and comprises the following specific steps:
1. adding the adipic acid stock solution with the concentration of 18% into a stock solution barrel for later use.
2. Adipic acid stock solution is guided into a preheating barrel through a stock solution barrel discharge pump to work, the temperature is raised to 40 ℃, the temperature rise time is not more than 3 mm, the preheating barrel needs to be raised in advance before the adipic acid stock solution enters, the time consumed by the temperature rise of the stock solution is reduced, meanwhile, the overlong temperature rise time of the stock solution is avoided, part of liquid is evaporated to influence the subsequent work, the mixing is carried out through a mixing device in the heating process, the internal dispersion of the adipic acid stock solution is driven, the large-area crystallization of the dispersibility of the stock solution is facilitated, and the crystallization granularity is uniform.
3. Starting a discharge pump of a preheating barrel, guiding stock solution into an evaporative crystallizer, heating the adipic acid stock solution to 50 ℃ through working of a heating chamber in the evaporative crystallizer, then feeding the adipic acid stock solution into a crystallization chamber in the evaporative crystallizer to boil the stock solution, gradually increasing the concentration of the stock solution to 48%, depositing part of solute on the surface of suspended crystal grains to form small-particle crystals, discharging the small-particle crystals through a discharge pump of the evaporative crystallizer, and reducing the temperature of the primary crystal liquid containing the small-particle crystals to 9 ℃ during discharging.
4. And continuously feeding the discharged primary crystallization liquid into a cooling crystallizer, and performing continuous heat exchange, cooling and crystallization for 6 hours to prepare adipic acid crystal slurry.
5. And (3) putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
Comparative example 2
In the comparative example of the present invention, the adipic acid re-melting, purifying and recrystallizing process provided in example 2 is adopted, only the circulation step between the heat recovery barrel and the cooling crystallizer is removed, and the cooling crystallizer is directly used for cooling crystallization, and the specific steps are similar to those of the crystallization process provided in comparative example 1, which are not repeated in detail.
Comparative example 3
In a comparative example of the present invention, the adipic acid re-melting, purifying and recrystallizing process provided in example 2 is adopted, only the circulation step between the heat recovery barrel and the cooling crystallizer is removed, and a cooling crystallizer is directly used for cooling crystallization, and the specific steps are identical to those of the crystallization process provided in comparative example 1, which are not repeated herein.
Comparative example 4
In the comparative example of the present invention, the adipic acid re-melting, purifying and recrystallizing process provided in example 2 is adopted, only the circulation step between the heat recovery barrel and the cooling crystallizer is removed, and the cooling crystallizer is directly used for cooling crystallization, and the specific steps are similar to those of the crystallization process provided in comparative example 1, which are not repeated in detail.
The specific parameters of comparative examples 1 to 4 above are shown in Table 2:
TABLE 2
The purity of adipic acid crystals was compared between examples 1 to 4 and comparative examples 1 to 4, and is shown in tables 3 and 4:
TABLE 3 purity index for examples 1-4
| Example 1 | Example 2 | Example 3 | Example 4 | |
| Purity of crystallization (%) | 99.48 | 99.61 | 99.72 | 99.57 |
TABLE 4 purity index for comparative examples 1-4
| Example 1 | Example 2 | Example 3 | Example 4 | |
| Purity of crystallization (%) | 96.73 | 97.11 | 97.81 | 97.08. |
As shown in tables 1 to 4, in comparison with examples 1 to 4, under the same parameters, comparative examples 1 to 4 have the crystallization purity of 99.48 to 99.72% and comparative examples 1 to 4 have the crystallization purity of 96.73 to 97.81% after only removing the circulation step between the heat recovery bucket and the cooling crystallizer and directly performing cooling crystallization by using the cooling crystallizer, so that comparative examples 1 to 4 are inferior to examples 1 to 4, thereby showing that the process of the present invention is an important factor for improving the crystallization purity of adipic acid.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and the preferred embodiments of the present invention are described in the above embodiments and the description, and the present invention is not limited to the embodiments, and various changes and modifications may be made without departing from the spirit and scope of the present invention, and these changes and modifications fall within the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (8)
1. The process for re-melting, purifying and recrystallizing adipic acid is characterized by comprising the following steps of:
s1, adding an adipic acid stock solution into a stock solution barrel for later use;
s2, enabling the adipic acid stock solution to work through a stock solution barrel discharge pump, and introducing the adipic acid stock solution into a preheating barrel to heat;
s3, starting a discharge pump of the preheating barrel, introducing the stock solution into an evaporative crystallizer, forming small-particle crystals in the adipic acid stock solution by the work of the evaporative crystallizer, and discharging the crystals by a discharge pump of the evaporative crystallizer;
s4, discharging the primary crystallization liquid, then feeding the discharged primary crystallization liquid into a heat recovery barrel to increase the liquid temperature, when the temperature of the primary crystallization liquid rises, enabling the crystals to re-melt, then starting a discharge pump of the heat recovery barrel to feed the heated primary crystallization liquid into a cooling crystallizer, and performing rapid cooling crystallization through a crystallization chamber of the cooling crystallizer to form a circulating crystallization liquid after crystallization;
s5, starting a circulating pump, discharging the circulating crystallization liquid from the cooling crystallizer, refluxing the circulating crystallization liquid to a heat recovery barrel for heat recovery and re-melting, and then starting a heat recovery barrel discharge pump to enable the re-melted circulating crystallization liquid to enter a cooling crystallization chamber again for crystallization, so that adipic acid crystal slurry can be prepared;
and S6, putting the adipic acid crystal slurry into a centrifugal separator, separating adipic acid crystals, and drying.
2. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: in the S1, the concentration of the adipic acid stock solution is 18-23%.
3. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: in the S2, the adipic acid stock solution is heated to 40-45 ℃ for no more than 3mim.
4. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: in S2, the preheating barrel needs to be heated up in advance before the adipic acid stock solution enters, and the adipic acid stock solution is stirred by the stirring device in the heating process to drive the adipic acid stock solution to be internally dispersed.
5. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: in the S3, the adipic acid stock solution is heated to 50-55 ℃, and the concentration of the stock solution is increased to 48-52%.
6. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: in the step S4, the temperature of the heat regeneration barrel is raised to 50-55 ℃ in advance, the primary crystallization liquid enters the heat regeneration barrel for the first time and stays for 30-40min, and the liquid temperature is raised.
7. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: and in the S5, the circulating crystallization liquid flows back to a heat recovery barrel, and is retained for 20-30min for heat recovery and re-melting at the temperature of 50-55 ℃.
8. The process of adipic acid remelting purification recrystallization according to claim 1, wherein: in the S5, the circulation step is performed for 6-7h for crystallization.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3096369A (en) * | 1957-12-09 | 1963-07-02 | Stamicarbon | Three step crystallization of adipic acid |
| GB1138351A (en) * | 1965-06-24 | 1969-01-01 | Ici Ltd | Recovery of adipic acid |
| KR20000016363A (en) * | 1996-06-04 | 2000-03-25 | 비날리 노엘 | Method for purifying adipic acid by crystallization |
| CN101219946A (en) * | 2007-12-25 | 2008-07-16 | 乳源瑶族自治县东阳光化成箔有限公司 | Method for recycling waste liquor of ammonium hexanedioic acid and recycling system thereof |
| CN102803197A (en) * | 2009-06-16 | 2012-11-28 | 罗地亚经营管理公司 | Method for producing crystals of adipic acid |
| CN111393286A (en) * | 2020-03-20 | 2020-07-10 | 武汉有机实业有限公司 | Device and process for purifying benzoic acid by step-by-step circulating crystallization |
-
2022
- 2022-07-01 CN CN202210782195.4A patent/CN115141095A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3096369A (en) * | 1957-12-09 | 1963-07-02 | Stamicarbon | Three step crystallization of adipic acid |
| GB1138351A (en) * | 1965-06-24 | 1969-01-01 | Ici Ltd | Recovery of adipic acid |
| KR20000016363A (en) * | 1996-06-04 | 2000-03-25 | 비날리 노엘 | Method for purifying adipic acid by crystallization |
| CN101219946A (en) * | 2007-12-25 | 2008-07-16 | 乳源瑶族自治县东阳光化成箔有限公司 | Method for recycling waste liquor of ammonium hexanedioic acid and recycling system thereof |
| CN102803197A (en) * | 2009-06-16 | 2012-11-28 | 罗地亚经营管理公司 | Method for producing crystals of adipic acid |
| CN111393286A (en) * | 2020-03-20 | 2020-07-10 | 武汉有机实业有限公司 | Device and process for purifying benzoic acid by step-by-step circulating crystallization |
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