CN111704537A - Preparation method of refined long-chain dicarboxylic acid - Google Patents
Preparation method of refined long-chain dicarboxylic acid Download PDFInfo
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- CN111704537A CN111704537A CN202010591209.5A CN202010591209A CN111704537A CN 111704537 A CN111704537 A CN 111704537A CN 202010591209 A CN202010591209 A CN 202010591209A CN 111704537 A CN111704537 A CN 111704537A
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- C07—ORGANIC CHEMISTRY
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- 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
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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
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
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- 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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Abstract
The invention relates to the technical field of preparation of long-chain dibasic acid, and discloses a preparation method of a refined long-chain dibasic acid product. The method comprises the following steps: (1) treating the fermentation liquor by using a filtering membrane to obtain a filtrate; (2) adding desalted water into the filtrate, then carrying out acidification crystallization, and filtering to obtain a crude product of the long-chain dicarboxylic acid; (3) dissolving the crude long-chain dibasic acid in a caustic soda solution, adding 1.2-1.8% of activated carbon for decoloring, and separating to obtain a decoloring solution; (4) and acidifying and crystallizing the decolorized solution again, and then filtering, washing and drying to obtain a refined long-chain dicarboxylic acid product. The invention adjusts the refining process of the long-chain dibasic acid, the filtrate is decolored by active carbon after being acidified and crystallized, and then is acidified and crystallized again, thereby not only reducing the operation difficulty and the refining cost and shortening the process flow, but also the quality of the prepared refined long-chain dibasic acid product is high, the content of the monoacid is up to 99.5 percent, and the content of the total acid is up to 99.7 percent.
Description
Technical Field
The invention relates to the technical field of preparation of long-chain dibasic acid, and particularly relates to a preparation method of a refined long-chain dibasic acid product.
Background
The Long chain dicarboxylic acids (Long chain dicarboxylic acids) refer to aliphatic dicarboxylic acids (n is 9-18) with more than 9 carbon atoms in the carbon chain, including saturated and unsaturated dicarboxylic acids, are important fine chemical products with wide industrial application, and are important raw materials for synthesizing high-grade spices, high-performance engineering plastics, high-temperature dielectrics, high-grade hot melt adhesives, cold-resistant plasticizers, high-grade lubricating oils, high-grade paints, coatings and the like in the chemical industry.
Long chain diacids do not occur in nature and certain classes of long chain diacids, such as sebacic acid and dodecanedioic acid, can be synthesized chemically. In addition, the long-chain dibasic acid can be produced by a biological method. The production of long-chain dibasic acid by microbial fermentation is the application of biochemical industry in the field of petrochemical industry, which is emerging in the seventies of the twentieth century. The biological method can provide a series of long-chain dicarboxylic acid monomers of C9-C18.
The microbial fermentation method is characterized in that alkane or fatty acid is used as a substrate, and is converted into fermentation liquor containing long-chain dibasic acid salt by microbial fermentation, the fermentation liquor contains thalli, residual alkane, fatty mixed acid and other impurities besides the long-chain dibasic acid salt, so that the fermentation liquor needs to be treated, and the long-chain dibasic acid salt in the fermentation liquor is converted into a long-chain dibasic acid product after being decolored and purified.
The prior dibasic acid refining process is to dissolve a dibasic acid crude product in an organic solvent, wherein acetic acid (acetic acid) is most widely used, but the organic solvent has a plurality of problems, wherein acid corrosion is caused, the cost is high, the requirement on the material of a process pipeline is high, the investment cost is high, the operation difficulty is high, and a high safety risk is caused.
Disclosure of Invention
The invention aims to solve the problems of high cost and high operation difficulty of the preparation process of the long-chain dibasic acid refined product in the prior art, and provides the preparation method of the long-chain dibasic acid refined product.
In order to achieve the purpose, the invention provides a preparation method of a refined long-chain dicarboxylic acid, which comprises the following steps:
(1) treating the fermentation liquor by using a filtering membrane to obtain a filtrate;
(2) adding desalted water into the filtrate obtained in the step (1), then carrying out acidification crystallization, and filtering to obtain a crude product of the long-chain dicarboxylic acid;
(3) dissolving the crude long-chain dibasic acid obtained in the step (2) in a caustic soda solution, then adding 1.2-1.8% of activated carbon for decoloring, and separating to obtain a decoloring solution;
(4) and (4) acidifying and crystallizing the decolorized solution obtained in the step (3) again, and then filtering, washing and drying to obtain a refined long-chain dicarboxylic acid product.
Preferably, in step (1), the fermentation liquid is a mixture containing long-chain dibasic acid salt obtained by microbial fermentation with water as a fermentation medium.
Preferably, before the fermentation broth is treated by the filtration membrane in step (1), the method further comprises heating the fermentation broth to 70-90 ℃ by a steam heat exchanger, and then adding caustic soda to adjust the pH value of the fermentation broth to 9.5-10.5.
Preferably, in the step (2), the volume ratio of the filtrate to the desalted water is 1 (1-1.5).
Preferably, in step (2), the acid used for acidifying the crystals is an inorganic acid, more preferably one or more of nitric acid, hydrochloric acid, sulfuric acid or phosphoric acid.
Preferably, in step (2), the conditions for the acidification crystallization are: the temperature is higher than 80 ℃; the pH is 2 to 5, more preferably 3 to 4.
Preferably, in step (3), the activated carbon is powdered activated carbon.
Preferably, in step (3), the decolorizing temperature is 20-50 ℃.
Preferably, in step (3), the pH of the destaining solution is controlled to be greater than 8.5.
Preferably, in step (4), the acid used for acidifying the crystals is an inorganic acid, more preferably one or more of nitric acid, hydrochloric acid, sulfuric acid or phosphoric acid.
More preferably, the acid used to acidify the crystals is sulfuric acid.
Preferably, in step (4), the conditions for the acidification crystallization are: the temperature is higher than 80 ℃; the pH value is 2-5, preferably 3-4.
More preferably, the pH of the acidified crystals is 3-3.5.
The invention can reduce the operation difficulty, reduce the refining cost and shorten the process flow by adjusting the refining flow of the long-chain dibasic acid. Specifically, the filtrate is acidified and crystallized, more than 70% of impurities in the filtrate can be left in the filtrate, and the obtained crude long-chain dicarboxylic acid product only contains a small amount of impurities. And then dissolving the long-chain dibasic acid crude product in caustic soda, and adding a certain amount of activated carbon for decoloring, wherein the decolored impurities are only the impurities left in the dibasic acid crude product, and are only a part of the filtrate, so that the decoloration effect of the activated carbon is more ideal.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The preparation method of the refined long-chain dicarboxylic acid comprises the following steps:
(1) treating the fermentation liquor by using a filtering membrane to obtain a filtrate;
(2) adding desalted water into the filtrate obtained in the step (1), then carrying out acidification crystallization, and filtering to obtain a crude product of the long-chain dicarboxylic acid;
(3) dissolving the crude long-chain dibasic acid obtained in the step (2) in a caustic soda solution, then adding 1.2-1.8% of activated carbon for decoloring, and separating to obtain a decoloring solution;
(4) and (4) acidifying and crystallizing the decolorized solution obtained in the step (3) again, and then filtering, washing and drying to obtain a refined long-chain dicarboxylic acid product.
The invention treats the fermentation liquor with a filtering membrane to obtain clear filtrate, and then the filtrate is acidified and crystallized, more than 70% of impurities in the filtered filtrate can be remained in the filtrate, and the obtained crude product of the long-chain dibasic acid only contains a small amount of impurities. And then dissolving the long-chain dibasic acid crude product in caustic soda, and adding a certain amount of activated carbon for decoloring, wherein the impurities for decoloring are only impurities in the long-chain dibasic acid crude product, and are only a part of the filtrate, so that the decoloring effect of the activated carbon is more ideal. Finally, the decolored solution is acidified and crystallized again, and the high-purity fine long-chain dicarboxylic acid can be obtained after post-treatment.
In the present invention, the long-chain dibasic acid is a saturated or unsaturated linear dibasic acid having 9 to 18 carbon atoms, with carboxyl groups at both ends of the carbon chain. Preferably, the long chain dibasic acid is azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, and 9-ene-octadecanedioic acid.
In the process of the present invention, the mode of treating the fermentation broth with a filtration membrane may be conventionally selected in the art. In a specific embodiment, the fermentation broth is treated with a filtration membrane, which may be a ceramic membrane filtration, followed by an ultrafiltration membrane filtration.
In the method of the invention, in the step (1), the fermentation liquor is a mixture containing long-chain dibasic acid salt obtained by microbial fermentation with water as a fermentation medium, and the fermentation liquor is obtained by microbial fermentation in the process of producing long-chain dibasic acid by a biological method.
In the method of the invention, before the fermentation liquor is treated by the filter membrane in the step (1), the method further comprises the step of heating the fermentation liquor to 70-90 ℃, preferably 85 ℃ by a steam heat exchanger; the pH of the fermentation broth is then adjusted to 9.5-10.5, preferably 10.2, by adding caustic soda.
In the method, in the step (2), when the desalted water is added, the volume ratio of the filtrate to the desalted water is controlled to be 1 (1-1.5); specifically, for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1: 1.5; preferably, in the step (2), when the desalted water is added, the volume ratio of the filtrate to the desalted water is controlled to be 1 (1-1.2).
In the method of the present invention, in the step (2), the acid used for the acidification crystallization may be an inorganic acid conventionally used in the art, and specifically, may be, for example, one or more of nitric acid, hydrochloric acid, sulfuric acid, or phosphoric acid.
In the method, in the step (2), the temperature of acidification crystallization is more than 80 ℃; preferably, the temperature of the acidification crystallization is 82-87 ℃. In step (2), the pH of the acidified crystals is from 2 to 5, preferably from 3 to 4.
In particular embodiments, the activated carbon may be powdered, granular, or columnar activated carbon. In a preferred embodiment, in step (3), the activated carbon is powdered activated carbon.
In specific embodiments, in step (3), 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, or 1.8% activated carbon may be added for decolorization.
In the method of the invention, in the step (3), the decoloring temperature is 20-50 ℃; specifically, for example, the temperature may be 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃ or 50 ℃; preferably, in the step (3), the decoloring temperature is 30 to 40 ℃.
In the step (3), after the activated carbon is decolorized, the pH value of the decolorized solution needs to be controlled to be more than 8.5; preferably, the pH value of the decoloration solution is controlled to be more than 8.6; more preferably, the pH of the destaining solution is controlled to be greater than 8.8.
In the method of the present invention, in the step (4), the acid used for the acidification crystallization may be an inorganic acid conventionally used in the art, and specifically, for example, may be one or more of nitric acid, hydrochloric acid, sulfuric acid, or phosphoric acid. In a preferred embodiment, in step (4), the acid used to acidify the crystals is sulfuric acid.
In the method of the present invention, in the step (4), the temperature of the acidification crystallization is more than 80 ℃, preferably more than 85 ℃; in step (4), the pH of the acidified crystals is 2 to 5, preferably 3 to 4, more preferably 3 to 3.5.
The invention adjusts the refining process of the long-chain dibasic acid, carries out acidification and crystallization on the filtrate, then carries out decolorization by using active carbon, and then carries out acidification and crystallization again, thereby not only reducing the operation difficulty and the refining cost and shortening the process flow, but also ensuring the quality of the prepared refined long-chain dibasic acid product to be high, wherein the content of the monoacid is up to 99.5 percent, and the content of the total acid is up to 99.7 percent.
The present invention will be described in detail by way of examples, but the scope of the present invention is not limited thereto.
Example 1
(1) Heating fermented twelve carbon dibasic acid fermentation liquor to 75 ℃ through a steam heat exchanger, adding caustic soda to adjust the pH value of the fermentation liquor to 10.2, and sequentially filtering the fermentation liquor by adopting a ceramic membrane and an ultrafiltration membrane to obtain filtrate;
(2) adding desalted water into the filtrate obtained in the step (1), wherein the volume ratio of the filtrate to the desalted water is 1:1, then adding sulfuric acid to adjust the pH value to 3.5, carrying out acidification crystallization at 85 ℃, and filtering to obtain a crude product of dodecanedioic acid;
(3) dissolving the crude dodecanedioic acid obtained in the step (2) in a caustic soda solution, adding 1.5% of powdered activated carbon for decoloring at 35 ℃, and separating to obtain a decoloring solution with the pH value of more than 8.5;
(4) and (4) heating the decolorized solution obtained in the step (3) to 90 ℃, adding sulfuric acid to adjust the pH value to 2.2, then carrying out acidification crystallization again, and then filtering, washing and drying to obtain a refined dodecanedioic acid product.
Example 2
(1) Heating fermented tetradecanoic acid fermentation liquor to 90 ℃ through a steam heat exchanger, adding caustic soda to adjust the pH value of the fermentation liquor to 9.5, and sequentially filtering the fermentation liquor by adopting a ceramic membrane and an ultrafiltration membrane to obtain filtrate;
(2) adding desalted water into the filtrate obtained in the step (1), wherein the volume ratio of the filtrate to the desalted water is 1:1.5, then adding hydrochloric acid to adjust the pH value to 2, carrying out acidification crystallization at 82 ℃, and filtering to obtain a crude tetradecanedioic acid product;
(3) dissolving the crude tetradecanedioic acid product obtained in the step (2) in a caustic soda solution, then adding 1.8% of granular activated carbon for decoloring at 20 ℃, and separating to obtain a decoloring solution with the pH value of more than 8.8;
(4) and (4) heating the decolorized solution obtained in the step (3) to 88 ℃, adding hydrochloric acid to adjust the pH value to 5, then carrying out acidification crystallization again, and then filtering, washing and drying to obtain a refined tetradecanedioic acid product.
Example 3
(1) Taking fermented azelaic acid fermentation liquor, heating the fermentation liquor to 70 ℃ through a steam heat exchanger, then adding caustic soda to adjust the pH value of the fermentation liquor to 10.5, and sequentially filtering the fermentation liquor by adopting a ceramic membrane and an ultrafiltration membrane to obtain filtrate;
(2) adding desalted water into the filtrate obtained in the step (1), wherein the volume ratio of the filtrate to the desalted water is 1:1.3, then adding nitric acid to adjust the pH value to 5, carrying out acidification crystallization at 87 ℃, and filtering to obtain a crude product of azelaic acid;
(3) dissolving the crude azelaic acid obtained in the step (2) in a caustic soda solution, then adding 1.2% of powdered activated carbon for decoloring at 50 ℃, and separating to obtain a decoloring solution with the pH value of more than 8.6;
(4) and (4) heating the decolorized solution obtained in the step (3) to 82 ℃, adding nitric acid to adjust the pH value to 2, then carrying out acidification crystallization again, and then filtering, washing and drying to obtain a refined azelaic acid.
Example 4
The procedure of example 1 was followed except that, in step (2), the volume ratio of the filtrate to the desalted water was 1: 1.4.
Example 5
The procedure of example 1 was followed, except that in the step (3), 1.6% of powdered activated carbon was added to conduct decolorization at 20 ℃.
Comparative example 1
The procedure of example 1 was repeated, except that the filtrate obtained in step (1) was decolorized with powdered activated carbon without conducting the operation of step (2).
Comparative example 2
The procedure of example 1 was followed except that, in step (2), the volume ratio of the filtrate to the desalted water was 1: 0.5.
Comparative example 3
The procedure is as in example 1, except that, in step (2), sulfuric acid is added to adjust the pH to 6.
Comparative example 4
The procedure of example 1 was followed, except that in the step (3), 1% powdered activated carbon was added for decolorization.
Comparative example 5
The procedure was as in example 1, except that in step (4), the decolorized solution obtained in step (3) was heated to 100 ℃.
Test example
The contents of the long chain dibasic acid mono-acid and the long chain dibasic acid total acid in weight percent prepared in examples 1 to 5 and comparative examples 1 to 5 were measured, and the results are shown in table 1. The measurement method can be determined by conventional methods known to those skilled in the art, for example, by the following test methods:
1. and (3) detecting long-chain dibasic acid monoacid:
the standard is Q/SH1185.201-1 test method;
2. detecting total acid of long-chain dicarboxylic acid:
the standard used was the Q/SH1185.201-2 test method.
TABLE 1
The results in table 1 show that the contents of the long-chain dicarboxylic acid monoacid and the long-chain dicarboxylic acid total acid prepared by the method are high and both reach more than 99.5%.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (10)
1. The preparation method of the refined long-chain dicarboxylic acid is characterized by comprising the following steps:
(1) treating the fermentation liquor by using a filtering membrane to obtain a filtrate;
(2) adding desalted water into the filtrate obtained in the step (1), then carrying out acidification crystallization, and filtering to obtain a crude product of the long-chain dicarboxylic acid;
(3) dissolving the crude long-chain dibasic acid obtained in the step (2) in a caustic soda solution, then adding 1.2-1.8% of activated carbon for decoloring, and separating to obtain a decoloring solution;
(4) and (4) acidifying and crystallizing the decolorized solution obtained in the step (3) again, and then filtering, washing and drying to obtain a refined long-chain dicarboxylic acid product.
2. The method according to claim 1, wherein in step (1), the fermentation liquid is a mixture containing long-chain dibasic acid salt obtained by microbial fermentation using water as a fermentation medium.
3. The method according to claim 1, wherein the step (1) further comprises heating the fermentation broth to 70-90 ℃ by a steam heat exchanger before treating the fermentation broth with the filtration membrane, and then adjusting the pH of the fermentation broth to 9.5-10.5 by adding caustic soda.
4. The method according to claim 1, wherein in the step (2), the volume ratio of the filtrate to the desalted water is 1 (1-1.5).
5. The method according to claim 1, wherein in step (2), the acid used for acidifying the crystals is an inorganic acid, preferably one or more of nitric acid, hydrochloric acid, sulfuric acid, or phosphoric acid.
6. The method of claim 1, wherein in step (2), the conditions for acidifying crystallization are: the temperature is higher than 80 ℃; the pH value is 2-5, preferably 3-4.
7. The method as claimed in claim 1, wherein, in the step (3), the activated carbon is powdered activated carbon.
8. The method according to claim 1, wherein, in the step (3), the decoloring temperature is 20 to 50 ℃;
preferably, in step (3), the pH of the destaining solution is controlled to be greater than 8.5.
9. The method according to claim 1, wherein in step (4), the acid used for acidifying the crystals is an inorganic acid, preferably one or more of nitric acid, hydrochloric acid, sulfuric acid or phosphoric acid, more preferably sulfuric acid.
10. The method of claim 1, wherein in step (4), the conditions for acidifying crystallization are: the temperature is higher than 80 ℃; the pH is 2 to 5, preferably 3 to 4, more preferably 3 to 3.5.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113248368A (en) * | 2021-05-19 | 2021-08-13 | 江苏达成生物科技有限公司 | Method for reducing content of acylglyceride impurities in long-chain dibasic acid |
| CN115181020A (en) * | 2021-04-02 | 2022-10-14 | 上海骆骐化学科技有限公司 | Extraction method of long-chain dicarboxylic acid |
-
2020
- 2020-06-25 CN CN202010591209.5A patent/CN111704537A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115181020A (en) * | 2021-04-02 | 2022-10-14 | 上海骆骐化学科技有限公司 | Extraction method of long-chain dicarboxylic acid |
| CN113248368A (en) * | 2021-05-19 | 2021-08-13 | 江苏达成生物科技有限公司 | Method for reducing content of acylglyceride impurities in long-chain dibasic acid |
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