CN114685259A - Crystallization method of long-chain dicarboxylic acid and refining method of long-chain dicarboxylic acid - Google Patents
Crystallization method of long-chain dicarboxylic acid and refining method of long-chain dicarboxylic acid Download PDFInfo
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- CN114685259A CN114685259A CN202011594403.5A CN202011594403A CN114685259A CN 114685259 A CN114685259 A CN 114685259A CN 202011594403 A CN202011594403 A CN 202011594403A CN 114685259 A CN114685259 A CN 114685259A
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- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
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- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
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- OOJGMLFHAQOYIL-UHFFFAOYSA-N hexadeca-2,4-dienoic acid Chemical compound CCCCCCCCCCCC=CC=CC(O)=O OOJGMLFHAQOYIL-UHFFFAOYSA-N 0.000 description 1
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- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/02—Preparation of carboxylic acids or their salts, halides or anhydrides from salts of carboxylic acids
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/47—Separation; Purification; Stabilisation; Use of additives by solid-liquid treatment; by chemisorption
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention provides a crystallization method and a refining method of long-chain dicarboxylic acid, wherein the crystallization process comprises the following steps: when the temperature of the acetic acid solution for dissolving the long-chain dicarboxylic acid is reduced to 70-75 ℃, closing the crystallization temperature control facility, starting to add water into the solution system at a constant speed, controlling the temperature reduction speed of the solution to be 0.2-1 ℃/min, in the process of continuously adding water, stopping adding water when the current temperature reduction speed is changed to be more than or equal to 0.1 ℃/min, preserving heat, and continuously reducing the temperature to crystallize the long-chain dicarboxylic acid. The invention adopts the mode of flowing water to reduce the solubility of long-chain dicarboxylic acid, locally reduces the temperature to stimulate a solution system to form dicarboxylic acid microcrystals, and combines temperature control to obtain granular rather than needle-shaped long-chain dicarboxylic acid crystals with larger and uniform granularity.
Description
Technical Field
The present invention relates to a method for crystallizing a long-chain dicarboxylic acid, particularly a method for crystallizing a long-chain dicarboxylic acid dissolved in acetic acid, and a method for purifying a long-chain dicarboxylic acid comprising the same.
Background
The long-chain dicarboxylic acid has two terminal carboxyl groups, so that the long-chain dicarboxylic acid is an important monomer raw material for synthesizing polymers such as high-performance engineering plastics, high-grade hot melt adhesives and the like.
The long chain dicarboxylic acids are metabolites of microbial fermentation. The fermentation liquor has complex composition, organic and inorganic substances such as microbial cells, cell fragments, culture media, proteins, amino acids, sugars, nucleic acids, lipids and the like, and the types and contents of impurities are continuously changed along with time and conditions, which all bring challenges for refining to obtain polymer-grade products.
Solvent recrystallization is a common technique for refining high-quality chemicals at present. The product prepared by the method has the advantages of high purity, good quality, capability of meeting the requirements of polymer grade and the like. The general technical process comprises the following steps: mixing the solvent and the crude raw material, dissolving, adsorbing impurities, crystallizing and the like. The polymer-grade long-chain dicarboxylic acid product is also produced by adopting a solvent recrystallization method, the industry mainly adopts a recrystallization refining method taking acetic acid as a solvent, and the process flow comprises the following steps: dissolving crude long-chain dicarboxylic acid with acetic acid, adsorbing with active carbon, and crystallizing. In the implementation process of the refining process, part of impurities in the crude long-chain dicarboxylic acid are adsorbed by activated carbon, and part of impurities are dissolved in a solvent in the crystallization process. However, the acetic acid process patents disclosed so far suffer from a number of deficiencies, particularly the feasibility of the crystallization control process. In the patent of refining long-chain dicarboxylic acid by using acetic acid as a solvent, such as the patent of CN 201010160266.4, clear liquid of dibasic acid is put into a primary crystallizing tank, the temperature is reduced to 75-85 ℃, the temperature is maintained for 1-2 hours, and then the temperature is reduced to 25-35 ℃. In the process of crystallization, seed crystals are not added for temperature reduction crystallization control. The long-chain dicarboxylic acid is difficult to spontaneously generate crystal nuclei in an acetic acid solution, and induced crystallization needs to be carried out under the action of an external source. In the cooling crystallization process, when crystal nuclei do not exist as attachment of crystal growth, crystals preferentially grow on a cooling interface, finally, long-chain dicarboxylic acid forms thick crystal scale on the inner wall of a crystallizer, so that the cooling heat transfer efficiency is low, crystals obtained in the cooling crystallization process without crystal seeds are different in size, and when massive crystal scale falls off under the stirring effect, pipelines are blocked, and the subsequent solid-liquid separation and production stability are affected. In the patent of CN201711410722.4, 0.1-1% of refined long-chain dicarboxylic acid is added as seed crystal in the crystallization process for induced cooling crystallization. However, the operation process is difficult to be effectively implemented, because the seed crystal is fine powder, when the seed crystal is added into a crystallization tank which is used for containing high-temperature acetic acid and has micro positive pressure to be crystallized, the powder seed crystal is easy to be blown out by acetic acid steam with positive pressure, and the powder seed crystal is easy to be soaked and agglomerated by acetic acid to block a feed inlet, thereby bringing uncertainty and operation danger for crystallization control.
In the patent disclosed in the above-mentioned patent for recrystallization refining of long-chain dicarboxylic acid by using acetic acid as a solvent, regarding the crystallization process control, only within a wide temperature range, seed crystals are added or not added, and then heat preservation is performed, and then direct cooling or segmented cooling is performed for crystallization, and there is no proposed crystallization control method which is easy to implement and is more precisely controlled, which is disadvantageous to the repeatability and reproducibility of the production process and the product quality. As is well known to those skilled in the art, the crystallization process control is a key technology for refining long-chain dicarboxylic acid by using acetic acid solvent, and in order to obtain an ideal crystallization state, seed crystals need to be added at a proper time, namely when the long-chain dicarboxylic acid in the acetic acid solution is supersaturated, the seed crystals are added, the seed crystals are dissolved and cannot perform the function of inducing crystallization, and when the seed crystals are added too late, a large amount of crystal nuclei are easily generated in a system, so that fine crystals are agglomerated to form needle-shaped or sheet-shaped crystals, and the product purity and the subsequent filtering and drying processes are affected. In large-scale production, the addition of seed crystals to control the crystallization process is difficult to operate, the solvent and the solute need to be accurately metered, and expensive detection equipment is needed to analyze and judge the seed crystal addition time, so that the cost is increased, and the production efficiency is reduced. And crystallization without seeding is obviously disadvantageous for large-scale production.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a crystallization method of long-chain dicarboxylic acid and a related purification method of long-chain dicarboxylic acid, and mainly relates to a crystallization method of long-chain dicarboxylic acid by taking acetic acid as a solvent and a purification method comprising the crystallization method
The molecular general formula of the long-chain dicarboxylic acid of the invention is C8-C18nH2n-2O4Wherein n is 8-18, and is a metabolite produced by fermentation of carbon sources such as alkane or fatty acid by microorganisms.
As is well known to those skilled in the art, the long chain dicarboxylic acid solvent recrystallization process involves: the main processes of dissolving crude long-chain dicarboxylic acid by acetic acid, adsorbing by activated carbon and crystallizing, wherein dissolving and adsorbing by activated carbon are conventional operation processes, and the control of the crystallization process is a key technology of the process, so that the step not only needs to obtain cleaner products, but also needs to control the operation to be easy to implement. The inventor unexpectedly discovers in research that a certain amount of water is added into the system at a certain speed in the process of cooling, when the temperature cooling speed of the solution system is reduced, tiny long-chain dicarboxylic acid crystal nuclei appear in the acetic acid solution, and at the moment, an inflection point appears in the temperature of the system, the temperature reduction range is small, and the temperature is prone to increase. The inventor adds acetic acid solution into water flow to initiate crystal nucleus, slows down the mark as crystal nucleus appearance and key parameters of crystal growth control at a temperature rate, combines heat preservation and program cooling control measures, establishes a crystallization control method which is easy to operate and realize, obtains long-chain dicarboxylic acid particle crystals reaching a polymerization level, and has higher crystallization yield than a crystallization process without water. Compared with the prior art, the method has the advantages of controllable implementation, no crystal scale generation, higher crystallization yield, product meeting the polymerization requirement and the like.
In order to achieve the purpose, the technical scheme of the invention is as follows:
the technical object of the first aspect of the present invention is to provide a method for crystallizing a long-chain dicarboxylic acid, comprising the steps of: when the temperature of the acetic acid solution for dissolving the long-chain dicarboxylic acid is reduced to 70-75 ℃, closing a crystallization temperature control facility, beginning to add water into the solution system at a constant speed, controlling the temperature reduction speed of the solution to be 0.2-1 ℃/min, preferably 0.2-0.8 ℃/min, more preferably 0.4-0.6 ℃/min, stopping adding water when the current post temperature reduction speed change is more than or equal to 0.1 ℃/min and the pre-and post temperature reduction speed change is more than or equal to 0.05 ℃/min in the process of continuously adding water, preserving the heat, and then continuously reducing the temperature to crystallize the long-chain dicarboxylic acid.
Further, in the above method, when the temperature reduction rate of the solution is not less than 0.5 ℃/min after the start of the addition of water, it is preferable to stop the addition of water when the temperature reduction rate is decreased to not more than 0.5 ℃/min and the change in the temperature reduction rate before and after is not less than 0.1 ℃/min, preferably the change in the temperature reduction rate before and after is not less than 0.05 ℃/min.
Further, the heat preservation time after the water addition is stopped is 30-60 min, so that the microcrystal in the system grows up.
Furthermore, the stirring is kept in the heat preservation process, as a more specific implementation mode, the stirring speed of the system is less than or equal to 50 r/min, the microcrystal is suspended at a proper rotating speed to be beneficial to crystal growing, and the shearing force generated by an overhigh rotating speed is easy to damage the crystal to form more crystal nuclei to be not beneficial to the growth of the microcrystal.
Furthermore, the temperature reduction rate of continuous temperature reduction is 7-15 ℃/h, the temperature of the crystallization end point is less than or equal to 20 ℃, the long-chain dicarboxylic acid is crystallized in a regular shape instead of needle-shaped fine crystals, and the subsequent solid-liquid separation operation and the improvement of the product quality are facilitated.
Further, in the acetic acid solution for dissolving the long-chain dicarboxylic acid, the acetic acid is more than or equal to 200 percent by weight of the long-chain dicarboxylic acid.
Further, the above-mentioned crystallization method further comprises a step of performing solid-liquid separation after the completion of the crystallization, wherein the solid-liquid separation is a step of separating the long-chain dicarboxylic acid crystals from the acetic acid solution by using a filtration apparatus such as centrifugation, pressure, vacuum, or the like to obtain the crystals, and the acetic acid solution and a small amount of the long-chain dicarboxylic acid dissolved therein are subjected to a recovery step.
Further, the temperature of water added into the system is 7-25 ℃, and the water is deionized water, distilled water or desalted water.
Further, the above-mentioned manner of adding water is selected from at least one of feeding, spraying and misting.
Further, the crystallization temperature control facility refers to equipment applied to crystallization temperature control in the prior art, and is preferably a cooling jacket.
Further, the above crystallization method may further comprise a step of adding a seed crystal of the long-chain dicarboxylic acid to the crystallization system, preferably before stopping the addition of water. The addition amount of the long-chain dicarboxylic acid seed crystals is 0.1-1% of the total amount of long-chain dicarboxylic acid in a crystallization system, preferably 0.1-0.8% of the total amount of long-chain dicarboxylic acid in the crystallization system, and more preferably 0.1-0.5% of the total amount of long-chain dicarboxylic acid in the crystallization system. The crystallization control process of adding water is assisted by adding the seed crystal, so that the crystallization control effect is more stable.
In the crystallization method, the solubility of long-chain dicarboxylic acid is reduced by adding water into an acetic acid solution, a solution system is stimulated to form dicarboxylic acid microcrystals by local temperature reduction, the trend of slowing down the temperature reduction speed is taken as a control index, and the crystallization control mode of temperature control and stirring control is combined to obtain the long-chain dicarboxylic acid crystals with larger and uniform granularity. Compared with the mode of adding crystal seeds to induce crystallization in the prior art, the mode of adding water to control crystallization has the advantages of good fluidity of medium, easy flowing addition, easy realization of operation, easy back mixing with acetic acid solution, easy uniform distribution nucleation in a system, and crystal formation on the basis, regular particle shape of crystal, convenient separation operation, high filtering speed and low water content. Meanwhile, the cooling capacity brought by water enables the cooling speed of the crystallization system to be higher, so that the phenomenon that crystallization is out of control because crystallization scars are formed on the wall of the crystallization tank jacket due to cooling to influence the cooling speed is prevented. The crystallization process is simple and convenient to control, and has practical application value.
The technical object of the second aspect of the present invention is to provide a method for purifying a long-chain dicarboxylic acid, comprising the steps of:
I. pretreating the terminated fermentation liquor, removing solid matters to obtain filtrate containing long-chain dicarboxylic acid salt;
II. Adding acid into the long-chain dicarboxylic acid salt filtrate to convert the long-chain dicarboxylic acid salt into long-chain dicarboxylic acid and completely separate out the long-chain dicarboxylic acid salt from the aqueous solution, and filtering to obtain a long-chain dicarboxylic acid filter cake;
III, adding acetic acid into the long-chain dicarboxylic acid filter cake, heating to dissolve the long-chain dicarboxylic acid, and filtering for clarification; adding an adsorbent into the filtrate to remove solid matters, so as to obtain an acetic acid solution in which the long-chain dicarboxylic acid is dissolved;
IV, cooling the acetic acid solution obtained in the step III to 70-75 ℃, then closing a crystallization temperature control facility, beginning to add water into the solution system at a constant speed, controlling the cooling speed of the solution to be 0.2-1 ℃/min, preferably 0.2-0.8 ℃/min, more preferably 0.4-0.6 ℃/min, stopping adding water when the current later cooling speed change is more than or equal to 0.1 ℃/min and preferably the front and back cooling speed change is more than or equal to 0.05 ℃/min in the continuous water adding process, keeping the temperature, and then continuously cooling to crystallize the long-chain dicarboxylic acid; carrying out solid-liquid separation to obtain long-chain dicarboxylic acid crystals;
v, adding the long-chain dicarboxylic acid crystals into water again, heating for washing, cooling, and performing solid-liquid separation and drying to obtain a fine long-chain dicarboxylic acid product.
Further, in the above method, the pretreatment in step I is to perform solid-liquid separation of solid matters such as bacteria and liquid by using solid-liquid separation equipment and means in the prior art, specifically, flocculation settling, centrifugal filtration, pressure filtration, vacuum filtration, microfiltration, ultrafiltration, and the like.
Further, the fermentation stopping liquid in the step I is a metabolite obtained by microbial fermentation, wherein the contained long-chain dicarboxylic acid has a molecular general formula of CnH2n-2O4Wherein n is 8-18, and can be single long-chain dicarboxylic acid or mixed long-chain dicarboxylic acid.
The acidification step II can be carried out by conventional methods in the prior art. Specifically, the pH value of acidification is 2.0-4.0. The acid used for acidification may be any concentration of H2SO4、HNO3、HCl、H3PO4Formic acid, acetic acid or propionic acid, etc. The long-chain dicarboxylic acid obtained by filtering can be directly mixed and dissolved with acetic acid or dried and then mixed and dissolved with the acetic acid.
Further, the amount of acetic acid used in step III is preferably 200% or more by weight of the cake of long-chain dicarboxylic acid.
Further, in the filtration and clarification in the step III, a filter having an aperture of not more than 5 μm is used, preferably an aperture of not more than 0.22 μm is used, and more preferably an aperture of not more than 0.1 μm is used. The inventor finds that the crude dicarboxylic acid is dissolved in an acetic acid solvent, insoluble solid exists in a solution system, the clarity is poor, pore channels of adsorbents such as activated carbon can be blocked, and adsorption and removal of impurities and pigments are not facilitated. In the prior art, the dissolving and the adsorption processes are coupled, and a filtering and clarifying step is rarely adopted before adsorption, so that the adsorption and the removal of impurities and pigments are not facilitated. Through the step of filtering and clarifying, the solution can be further clarified, so that the adsorption efficiency of the subsequent adsorbent is higher, and the quality of the obtained refined dicarboxylic acid is better.
Further, the adsorbent in the step III is selected from adsorbents commonly used in the industry, preferably activated carbon, and the using amount of the activated carbon is 0.1-4.0% of the total amount of the long-chain dicarboxylic acid. The adsorption temperature is more than or equal to 65 ℃, and is preferably 10-30 ℃ higher than the temperature of dissolving the long-chain dicarboxylic acid in the acetic acid.
Further, the solid-liquid mixed solution after adsorption treatment in the step III is subjected to solid-liquid separation and clarification in a graded filtration mode. In a more specific embodiment, a filter medium with a pore size of 10 to 50 μm is used to filter and remove solid matters such as activated carbon to obtain a first-stage filtrate, and a filter medium with a pore size of 0.2 to 1 μm is used to remove the remaining solid matters to obtain a clear and colorless second-stage filtrate.
Further, the temperature of the water added into the system in the step IV is 7-25 ℃, and the water is deionized water, distilled water or desalted water. The water is added by at least one selected from the group consisting of feeding, spraying and misting.
Further, in the step IV, when the water is added, the cooling speed of the solution is more than or equal to 0.5 ℃/min, the water is stopped adding when the cooling speed is reduced to 0.5 ℃/min and the change of the front and back cooling speed is more than or equal to 0.1 ℃/min, preferably the change of the front and back cooling speed is more than or equal to 0.05 ℃/min. The heat preservation time after the water addition is stopped is 30-60 min; the temperature reduction rate of the continuous temperature reduction is 7-15 ℃/h; the temperature of the crystallization end point is less than or equal to 20 ℃. More specifically, the stirring is kept in the heat preservation process, the stirring rotating speed of the system is less than or equal to 50 revolutions per minute, the microcrystal suspension is beneficial to crystal growing through proper revolution, and shearing force generated by overhigh revolution easily breaks crystals to form more crystal nuclei, so that the growth of the microcrystal is not facilitated.
Further, the step IV comprises a step of adding a long-chain dicarboxylic acid seed crystal to the crystallization system, and preferably, the addition is stopped before the addition of water. The addition amount of the long-chain dicarboxylic acid seed crystals is 0.1-1% of the total amount of long-chain dicarboxylic acid in a crystallization system, preferably 0.1-0.8% of the total amount of long-chain dicarboxylic acid in the crystallization system, and more preferably 0.1-0.5% of the total amount of long-chain dicarboxylic acid in the crystallization system.
Further, the step IV of obtaining the long-chain dicarboxylic acid crystal through solid-liquid separation is to separate the long-chain dicarboxylic acid crystal from the acetic acid solution by adopting filtering equipment such as centrifugation, pressure, vacuum and the like to obtain the crystal, and the acetic acid solution and a small amount of the long-chain dicarboxylic acid dissolved in the acetic acid solution are recycled.
In the crystallization process in the step IV, the obtained long-chain dicarboxylic acid crystals are regular, are not needle-shaped and other fine crystals, and are beneficial to subsequent solid-liquid separation operation and improvement of product quality.
Further, in the step V, the long-chain dicarboxylic acid crystal obtained in the step IV is resuspended in water, the temperature is controlled to be 70-100 ℃, the heat preservation time is 60-120 min, the temperature is reduced to the end point temperature not higher than 20 ℃, the crystallization material is subjected to solid-liquid separation to obtain a wet binary acid product, and finally the wet binary acid product is dried in a dryer to obtain a fine long-chain dicarboxylic acid product.
By the refining method, the long-chain dicarboxylic acid is separated from impurities more thoroughly, the product is white in color and luster, and has practical application value, the purity of the obtained product is more than 99.5%, the total nitrogen content is less than 20ppm, and the requirements of downstream polymerization application can be met.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Detailed Description
The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.
The following examples and comparative examples respectively show the technical scheme of the present invention and the purification method of long chain dicarboxylic acid in the prior art:
example 1
I. Filtering the fermentation liquor containing deca-carbo-carboxylic acid to remove solid impurities such as thalli;
II. Adding sulfuric acid into the product I to separate out deca-carboxylic acid, and filtering to obtain a coarse deca-carboxylic acid filter cake;
III, adding 50 liters of acetic acid into a 100L dissolving kettle, adding 25kg of deca-dicarboxylic acid crude product, heating to 83 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, clarifying the solution by a 0.1-micron pore filter, and then feeding the solution into a decoloring kettle. Adding 0.25kg of active carbon into a decoloring kettle, uniformly stirring, adsorbing for 30 minutes at 80 ℃, allowing a decoloring solution to sequentially pass through a 10-micron filter and a 0.2-micron filter, and allowing a deca-dicarboxylic acid solution to enter a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, cooling the solution to be crystallized to 72 ℃ under stirring, closing the cooling system, adding 20 ℃ desalted water at a constant speed in a flowing manner, controlling the cooling rate of the system to be 0.6 ℃/min, reducing the temperature of the system along with the constant speed in the flowing manner, beginning to separate out deca-carbo-xylic acid when the solubility of deca-carbo-xylic acid is reduced, discharging a small amount of heat, reducing the temperature in the kettle to 0.5 ℃/min, continuing to add water in the flowing manner, continuing to separate out deca-carbo-ylic acid, closing a desalted water flowing electromagnetic valve when the temperature in the kettle is reduced to 0.4 ℃/min from 0.5 ℃/min, starting a heat preservation mode, controlling the stirring speed, preserving the heat for 30min, opening the cooling system, starting a program to reduce the temperature, controlling the cooling amplitude to be 8 ℃/h, and finally cooling to be 20 ℃. And (3) carrying out solid-liquid separation on the crystallization liquid, wherein the deca-carbon carboxylic acid crystals are in regular particles, the separation operation is convenient, the filtering speed is high, the water content is low, and the deca-carbon carboxylic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 50L of desalted water into the recrystallization tank, keeping the temperature at 90 ℃, stirring for 40r/min, preserving the temperature for 60min, starting a program to cool, and cooling to 20 ℃. And (4) carrying out solid-liquid separation to obtain a deca-carbon dicarboxylic acid wet filter cake, and drying by using a dryer to obtain the refined deca-carbon dicarboxylic acid. The quality indexes of the refined deca-carbolic acid products are shown in Table 1.
Example 2
I. Filtering the fermentation liquor containing the dodecacarbolic acid to remove solid impurities such as thalli and the like;
II. Adding sulfuric acid into the product I to separate out the dodecacarbolic acid, and filtering to obtain a crude dodecacarbolic acid filter cake;
III, adding 55 liters of acetic acid into a 100L dissolving kettle, adding 25kg of crude dodecanedicarboxylic acid, heating to 85 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, and clarifying the solution through a 0.1-micron pore filter and then entering a decoloring kettle. Adding 0.4kg of active carbon into a decoloring kettle, uniformly stirring, adsorbing at 82 ℃ for 30 minutes, passing a decoloring solution through a 10-micron filter and a 0.2-micron filter in sequence, and feeding a dodecanedicarboxylic acid solution into a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, cooling the solution to be crystallized to 75 ℃ under stirring, closing the cooling system, adding desalted water of 15 ℃ at a constant speed in a flowing manner, controlling the cooling rate of the system to be 0.6 ℃/min, reducing the cooling rate along with the adding of the desalted water at the constant speed, closing a desalted water flow adding electromagnetic valve when the temperature in the kettle is reduced from 0.4 ℃/min to 0.3 ℃/min, starting a heat preservation mode, controlling the stirring speed, preserving the temperature for 30min, starting the cooling system, starting a program to cool, controlling the cooling amplitude to be 10 ℃/h, and finally cooling to 20 ℃. And (4) carrying out solid-liquid separation on the crystallization liquid, wherein the deca-dicarbonyl carboxylic acid crystals are in regular particles, and the separation operation is convenient, so that a dodeca-dicarbonyl carboxylic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 60L of desalted water into the recrystallization tank, keeping the temperature at 85-90 ℃, stirring for 40r/min, preserving the temperature for 60min, starting a program to cool, and cooling to 20 ℃. And (4) carrying out solid-liquid separation to obtain a dodecacarbolic acid wet filter cake, and drying by using a dryer to obtain the refined dodecacarbolic acid. The quality indexes of the refined dodecanedicarboxylic acid products are shown in Table 1.
Example 3
I. Filtering the fermentation liquor containing the tridecanedicarboxylic acid to remove solid impurities such as thalli and the like;
II. Adding sulfuric acid into the product I to separate out tridecanedicarboxylic acid, and filtering to obtain a coarse product of a tridecanedicarboxylic acid filter cake;
III, adding 53 liters of acetic acid into a 100L dissolving kettle, adding 22kg of a crude tridecadiylcarboxylic acid product, heating to 81 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, clarifying the solution by a 0.1-micron pore filter, and then feeding the solution into a decoloring kettle. Adding 0.3kg of active carbon into a decoloring kettle, uniformly stirring, adsorbing at 78 ℃ for 30 minutes, passing a decoloring solution through a 10-micron filter and a 0.2-micron filter in sequence, and feeding a tridecanedicarboxylic acid solution into a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, cooling the solution to be crystallized to 73 ℃ under stirring, closing the cooling system, adding desalted water of 20 ℃ at a constant speed in a flowing manner, controlling the cooling rate of the system to be 0.5 ℃/min, reducing the cooling rate along with the adding of the desalted water at the constant speed, closing a desalted water flow adding electromagnetic valve when the temperature in the kettle is reduced to 0.2 ℃/min from 0.3 ℃/min, starting a heat preservation mode, controlling the stirring speed, preserving the heat for 50min, starting the cooling system, starting a program to cool, controlling the cooling amplitude to be 10 ℃/h, and finally cooling to 20 ℃. And (4) carrying out solid-liquid separation on the crystallization liquid, wherein the deca-carbon dicarboxylic acid crystals are in regular particles, and the separation operation is convenient, so that a tridecyl dicarboxylic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 55L of desalted water into the recrystallization tank, keeping the temperature at 80 ℃, stirring for 40r/min, keeping the temperature for 60min, starting a program to cool, and cooling to 20 ℃. And (4) carrying out solid-liquid separation to obtain a tridecanedicarboxylic acid wet filter cake, and drying by using a dryer to obtain refined tridecanedicarboxylic acid. The quality indexes of the refined tridecadicarboxylic acid products are shown in table 1.
Example 4
I. Filtering the fermentation liquor containing the tetradecadienoic acid to remove solid impurities such as thalli and the like;
II. Adding sulfuric acid into the product I to separate out tetradecadienoic acid, and filtering to obtain a crude tetradecadienoic acid filter cake;
III, adding 55 liters of acetic acid into a 100L dissolving kettle, adding 26kg of crude tetradecadienoic acid, heating to 90 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, and clarifying the solution through a 0.1-micron pore filter and then feeding the solution into a decoloring kettle. Adding 0.2kg of active carbon into a decoloring kettle, stirring uniformly, adsorbing at 85 ℃ for 30 minutes, passing decolored liquid through a 10-micron filter and a 0.2-micron filter in sequence, and feeding the tetradecadienoic acid solution into a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, cooling the solution to be crystallized to 74 ℃ under stirring, closing the cooling system, adding desalted water of 20 ℃ at a constant speed in a flowing manner, controlling the cooling rate of the system to be 0.6 ℃/min, reducing the cooling rate along with the adding of the desalted water at the constant speed, closing a desalted water flow adding electromagnetic valve when the temperature in the kettle is reduced from 0.5 ℃/min to 0.3 ℃/min, starting a heat preservation mode, controlling the stirring speed, preserving the heat for 40min, starting the cooling system, starting a program to cool, controlling the cooling amplitude to be 12 ℃/h, and finally cooling to 20 ℃. And (4) carrying out solid-liquid separation on the crystallization liquid, wherein the deca-carbon dicarboxylic acid crystals are in regular particles, and the separation operation is convenient, so that a tetradecadienoic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 60L of desalted water into the recrystallization tank, keeping the temperature at 90 ℃, stirring for 40r/min, keeping the temperature for 60min, starting a program to cool, and cooling to 20 ℃. And (4) carrying out solid-liquid separation to obtain a tetradecadienoic acid wet filter cake, and drying by using a dryer to obtain the refined tetradecadienoic acid. The quality indexes of the refined tetradecadienoic acid products are shown in Table 1.
Example 5
I. Filtering the fermentation liquor containing the pentadecacarbo-carboxylic acid, and removing solid impurities such as thalli and the like;
II. Adding sulfuric acid into the product I to separate out pentadecacarbo-carboxylic acid, and filtering to obtain a pentadecacarbo-carboxylic acid filter cake crude product;
and III, adding 60 liters of acetic acid into a 100L dissolving kettle, adding 25kg of crude pentadecacarbodicarboxylic acid, heating to 85 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, and clarifying the solution by a 0.1-micron pore filter and then feeding the solution into a decoloring kettle. Adding 0.3kg of activated carbon into a decoloring kettle, uniformly stirring, adsorbing at 80-85 ℃ for 30 minutes, allowing a decoloring solution to pass through a 10-micron filter and a 0.2-micron filter in sequence, and allowing a pentadecadienecarboxylic acid solution to enter a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, cooling the solution to be crystallized to 73 ℃ under stirring, closing the cooling system, adding desalted water of 20 ℃ at a constant speed in a flowing manner, controlling the cooling rate of the system to be 0.4 ℃/min, reducing the cooling rate along with the adding of the desalted water at the constant speed, closing a desalted water flow adding electromagnetic valve when the temperature in the kettle is reduced to 0.1 ℃/min from 0.3 ℃/min, starting a heat preservation mode, controlling the stirring speed, preserving the heat for 60min, starting the cooling system, starting a program to cool, controlling the cooling amplitude to be 10 ℃/h, and finally cooling to 20 ℃. And (4) carrying out solid-liquid separation on the crystallization liquid, wherein the deca-carbon carboxylic acid crystals are in regular particles, and the separation operation is convenient, so that a pentadeca-carbon carboxylic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 60L of desalted water into the recrystallization tank, keeping the temperature at 85 ℃, stirring for 40r/min, keeping the temperature for 60min, starting a program to cool, and cooling to 20 ℃. And carrying out solid-liquid separation to obtain a pentadecacarbondicarboxylic acid wet filter cake, and drying by using a dryer to obtain the refined pentadecacarbondicarboxylic acid. The quality indexes of the refined pentadecacarbodicarboxylic acid products are shown in Table 1.
Example 6
I. Filtering the fermentation liquor containing the dodecacarbolic acid to remove solid impurities such as thalli and the like;
II. Adding sulfuric acid into the product I to separate out the dodecacarbolic acid, and filtering to obtain a crude dodecacarbolic acid filter cake;
III, adding 55 liters of acetic acid into a 100L dissolving kettle, adding 25kg of crude dodecanedicarboxylic acid, heating to 85 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, and clarifying the solution through a 0.1-micron pore filter and then entering a decoloring kettle. Adding 0.4kg of active carbon into a decoloring kettle, uniformly stirring, adsorbing at 82 ℃ for 30 minutes, passing a decoloring solution through a 10-micron filter and a 0.2-micron filter in sequence, and feeding a dodecanedicarboxylic acid solution into a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, cooling the solution to be crystallized to 75 ℃ under stirring, closing the cooling system, adding desalted water of 15 ℃ at a constant speed in a flowing manner, controlling the cooling rate of the system to be 0.6 ℃/min, adding desalted water along with the constant speed in the flowing manner, reducing the cooling rate, adding 50g of dodecacarboncarboxylic acid seed crystal when the temperature in the kettle is reduced to 0.3 ℃/min from 0.4 ℃/min, closing the desalted water flowing and adding electromagnetic valve, starting a heat preservation mode, controlling the stirring speed, preserving the heat for 30min, opening the cooling system, starting a program to cool, controlling the cooling amplitude to be 10 ℃/h, and finally cooling to 20 ℃. And (4) carrying out solid-liquid separation on the crystallization liquid, wherein the deca-dicarbonyl carboxylic acid crystals are in regular particles, and the separation operation is convenient, so that a dodeca-dicarbonyl carboxylic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 60L of desalted water into the recrystallization tank, keeping the temperature at 85-90 ℃, stirring for 40r/min, preserving the temperature for 60min, starting a program to cool, and cooling to 20 ℃. And (4) carrying out solid-liquid separation to obtain a dodecacarbolic acid wet filter cake, and drying by using a dryer to obtain the refined dodecacarbolic acid. The quality indexes of the refined dodecanedicarboxylic acid products are shown in Table 1.
Comparative example 1
I. Filtering the fermentation liquor containing the dodecacarbolic acid to remove solid impurities such as thalli and the like;
II. Adding sulfuric acid into the product I to separate out the dodecacarbolic acid, and filtering to obtain a crude dodecacarbolic acid filter cake;
and III, putting 55 liters of acetic acid into a 100L dissolving kettle, adding 25kg of crude dodecanedicarboxylic acid, heating to 85 ℃, keeping the temperature and stirring to fully dissolve the dibasic acid, and feeding the dibasic acid into a decoloring kettle. Adding 0.4kg of active carbon into a decoloring kettle, uniformly stirring, adsorbing at 82 ℃ for 30 minutes, passing a decoloring solution through a 10-micron filter and a 0.2-micron filter in sequence, and feeding a dodecanedicarboxylic acid solution into a crystallization kettle.
And IV, starting a cooling system of the crystallization kettle, adding 200g of dodecanedicarboxylic acid with the purity of more than 99.8 percent as seed crystals when the temperature of the crystallization solution is reduced to 73 ℃ under stirring, controlling the stirring speed to be 40r/min, controlling the temperature in the crystallization kettle to be 75 ℃, then naturally reducing the temperature to 68 ℃, starting the cooling system, and controlling the cooling speed to finally reduce the temperature to 20 ℃. And (4) carrying out solid-liquid separation on the crystallization liquid, wherein the crystallization is irregular crystallization agglomerates, so that the moisture content of a filter cake obtained by filtering is higher, and the dodecacarbolic acid crystal filter cake is obtained.
V, conveying the filter cake to a recrystallization tank, adding 60L of desalted water into the recrystallization tank, keeping the temperature at 90 ℃, stirring for 40r/min, preserving the temperature for 120min, starting a program to cool, and cooling to 30 ℃. And (4) carrying out solid-liquid separation to obtain a dodecacarbolic acid wet filter cake, and drying by using a dryer to obtain the refined dodecacarbolic acid. The quality indexes of the refined dodecanedicarboxylic acid products are shown in Table 1.
Table 1.
Claims (21)
1. A method of crystallizing a long chain dicarboxylic acid comprising the steps of: when the temperature of the acetic acid solution for dissolving the long-chain dicarboxylic acid is reduced to 70-75 ℃, closing a crystallization temperature control facility, beginning to add water into the solution system at a constant speed, controlling the temperature reduction speed of the solution to be 0.2-1 ℃/min, preferably 0.2-0.8 ℃/min, more preferably 0.4-0.6 ℃/min, stopping adding water when the current post temperature reduction speed change is more than or equal to 0.1 ℃/min and the pre-and post temperature reduction speed change is more than or equal to 0.05 ℃/min in the process of continuously adding water, preserving the heat, and then continuously reducing the temperature to crystallize the long-chain dicarboxylic acid.
2. The crystallization method according to claim 1, wherein when the cooling rate of the solution is equal to or greater than 0.5 ℃/min after the start of the addition of water, the addition of water is stopped when the cooling rate is decreased to less than 0.5 ℃/min and the change in the cooling rate before and after the start is equal to or greater than 0.1 ℃/min.
3. The crystallization method according to claim 1, wherein the holding time after the water addition is stopped is 30 to 60 min.
4. The crystallization method according to claim 3, wherein the stirring is maintained during the heat preservation, and the stirring speed is not more than 50 revolutions per minute.
5. The crystallization method as claimed in claim 1, wherein the temperature reduction rate of the continuous temperature reduction is 7-15 ℃/h, and the temperature of the crystallization end point is less than or equal to 20 ℃.
6. The crystallization method according to claim 1, wherein the solution of the long-chain dicarboxylic acid in acetic acid is not less than 200% by weight of the long-chain dicarboxylic acid.
7. The crystallization method according to claim 1, further comprising a step of performing solid-liquid separation after the crystallization is completed.
8. The crystallization method according to claim 1, wherein the temperature of water added to the system is 7 to 25 ℃, and the water is deionized water, distilled water or desalted water.
9. The crystallization method according to claim 1, wherein the water is added by at least one selected from the group consisting of feeding, spraying and misting.
10. The crystallization method according to claim 1, further comprising a step of adding a seed crystal of the long-chain dicarboxylic acid to the crystallization system.
11. The crystallization method according to claim 10, wherein the seed crystals are added in an amount of 0.1 to 1% by weight based on the total amount of the long-chain dicarboxylic acid in the crystallization system.
12. A method for refining long-chain dicarboxylic acid, comprising the steps of:
I. pretreating the fermentation broth, and removing solids to obtain a filtrate containing long-chain dicarboxylic acid salt;
II. Adding acid into the long-chain dicarboxylic acid salt filtrate to convert the long-chain dicarboxylic acid salt into long-chain dicarboxylic acid and completely separate out the long-chain dicarboxylic acid salt from the aqueous solution, and filtering to obtain a long-chain dicarboxylic acid filter cake;
III, adding acetic acid into the long-chain dicarboxylic acid filter cake, heating to dissolve the long-chain dicarboxylic acid, filtering and clarifying; adding an adsorbent into the filtrate, and removing solid matters to obtain an acetic acid solution in which the long-chain dicarboxylic acid is dissolved;
IV, cooling the acetic acid solution obtained in the step III to 70-75 ℃, closing a crystallization temperature control facility, starting to add water into the solution system at a constant speed, controlling the cooling speed of the solution to be 0.2-1 ℃/min, preferably 0.2-0.8 ℃/min, more preferably 0.4-0.6 ℃/min, stopping adding water when the current rear cooling speed change is more than or equal to 0.1 ℃/min and preferably the front and rear cooling speed change is more than or equal to 0.05 ℃/min in the continuous water adding process, preserving heat, and then continuously cooling to crystallize the long-chain dicarboxylic acid; carrying out solid-liquid separation to obtain long-chain dicarboxylic acid crystals;
v, adding the long-chain dicarboxylic acid crystals into water again, heating for washing, cooling, and performing solid-liquid separation and drying to obtain a fine long-chain dicarboxylic acid product.
13. Refining process according to claim 12, characterized in that the amount of acetic acid used in step III, preferably ≥ 200% by weight of the cake of long-chain dicarboxylic acid.
14. The refining method according to claim 12, wherein the filtration clarification in step III is a filter having a pore size not more than 5 μm.
15. The refining method according to claim 12, wherein the solid-liquid mixed solution after adsorption treatment in step III is subjected to solid-liquid separation and clarification by means of fractional filtration: filtering with a filter material with the aperture of 10-50 mu m to remove solid matters such as active carbon and the like to obtain a primary filtrate, and removing the residual solid matters with the filter material with the aperture of 0.2-1 mu m to obtain a clear colorless secondary filtrate.
16. The refining method of claim 12, wherein in step IV, when the water is added and the cooling rate of the solution is not less than 0.5 ℃/min, the water is stopped when the cooling rate is reduced to less than 0.5 ℃/min and the change of the cooling rate before and after the water is added is not less than 0.1 ℃/min.
17. The refining method according to claim 12, wherein the temperature of the water added to the system in the step iv is 7 to 25 ℃, and the water is deionized water, distilled water or desalted water; the water is added by at least one selected from the group consisting of feeding, spraying and misting.
18. The refining method according to claim 12, wherein the holding time after the water addition is stopped in the step IV is 30-60 min; the temperature reduction rate of the continuous temperature reduction is 7-15 ℃/h; the temperature of the crystallization end point is less than or equal to 20 ℃.
19. The refining method of claim 18, wherein the stirring is maintained during the heat preservation, and the stirring speed of the system is less than or equal to 50 rpm.
20. The refining method according to claim 12, wherein the step IV further comprises a step of adding a seed crystal of the long-chain dicarboxylic acid to the crystallization system, the seed crystal being added before the addition of water is stopped; the addition amount of the seed crystal is 0.1-1% of the total amount of the long-chain dicarboxylic acid in the crystallization system.
21. The refining method according to claim 12, wherein in the step V, the long-chain dicarboxylic acid crystals obtained in the step IV are resuspended in water, the temperature is controlled to be 70-100 ℃, the heat preservation time is 60-120 min, the temperature is reduced to the end point temperature not higher than 20 ℃, the crystallized material is subjected to solid-liquid separation to obtain a wet binary acid product, and finally the wet binary acid product is dried in a dryer to obtain a fine long-chain dicarboxylic acid product.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012180306A (en) * | 2011-03-01 | 2012-09-20 | Mitsubishi Chemicals Corp | Aliphatic dicarboxylic acid crystal and method for producing aliphatic dicarboxylic acid |
| US20130116471A1 (en) * | 2011-09-30 | 2013-05-09 | Shandong Hilead Biotechnology Co., Ltd. | Process for preparing long-chain dicarboxylic acids and the production thereof |
| CN103804172A (en) * | 2012-11-08 | 2014-05-21 | 中国石油化工股份有限公司 | Method for improving organic acid product quality |
| CN108003015A (en) * | 2017-12-23 | 2018-05-08 | 淄博广通化工有限责任公司 | The process for refining and purifying of Long carbon chain dicarboxylic acids |
| CN110002992A (en) * | 2019-03-24 | 2019-07-12 | 张艾琳 | A kind of refining methd of positive long-chain biatomic acid |
| CN111099990A (en) * | 2019-12-31 | 2020-05-05 | 淄博广通化工有限责任公司 | Method for recycling mother liquor of long carbon chain dicarboxylic acid refining crystallization |
-
2020
- 2020-12-29 CN CN202011594403.5A patent/CN114685259A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012180306A (en) * | 2011-03-01 | 2012-09-20 | Mitsubishi Chemicals Corp | Aliphatic dicarboxylic acid crystal and method for producing aliphatic dicarboxylic acid |
| US20130116471A1 (en) * | 2011-09-30 | 2013-05-09 | Shandong Hilead Biotechnology Co., Ltd. | Process for preparing long-chain dicarboxylic acids and the production thereof |
| CN103804172A (en) * | 2012-11-08 | 2014-05-21 | 中国石油化工股份有限公司 | Method for improving organic acid product quality |
| CN108003015A (en) * | 2017-12-23 | 2018-05-08 | 淄博广通化工有限责任公司 | The process for refining and purifying of Long carbon chain dicarboxylic acids |
| CN110002992A (en) * | 2019-03-24 | 2019-07-12 | 张艾琳 | A kind of refining methd of positive long-chain biatomic acid |
| CN111099990A (en) * | 2019-12-31 | 2020-05-05 | 淄博广通化工有限责任公司 | Method for recycling mother liquor of long carbon chain dicarboxylic acid refining crystallization |
Non-Patent Citations (1)
| Title |
|---|
| 龚俊波;朱明河;张辉;尹秋响;: "长链二元酸的水相反应结晶过程研究", 天津大学学报(自然科学与工程技术版), no. 08, 23 July 2018 (2018-07-23), pages 2 * |
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