Continuous crystallization process of high-purity succinic acid

Abstract

The invention relates to the technical field of succinic acid crystallization processes, in particular to a continuous crystallization process of high-purity succinic acid. A succinic acid solution is prepared through an oxidation reaction of a butadiene solution, and a stabilizer is added. A succinic acid solution is added into a microbial fermentation reactor, and organic impurities are converted into harmless substances through microbial strains. The succinic acid in the solution is crystallized by cooling in a crystallizer, and the crystallinity and the purity are regulated by adding a plant regulator. And filtering, washing and drying to obtain a high-purity succinic acid crystal product. And meanwhile, the residual solvent in the crystallized product is recovered and utilized, and the solvent is recovered through distillation and is reused in the production process of succinic acid. The process has the advantages that the crystallization rate, size and purity of succinic acid are improved, the production cost is reduced, and the unification of economic and environment-friendly benefits is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of succinic acid crystallization processes, and more specifically, to a continuous crystallization process for high-purity succinic acid. Background Art

[0002] Succinic acid is an important chemical raw material, widely used in fields such as polyester resins, coatings, plastics, and pharmaceuticals. Traditional methods for producing succinic acid mainly involve electrochemical or catalytic hydrogenation methods, but these methods have problems such as high energy consumption, complex processes, and environmental pollution. In recent years, the microbial fermentation method has emerged as a new way to produce succinic acid, with advantages such as low energy consumption, simple processes, and environmental friendliness. The succinic acid products produced by the microbial fermentation method have relatively low purity and need to further improve their purity and crystallization rate to meet the requirements of industrial production.

[0003] Currently, in the succinic acid products produced by the microbial fermentation method, the crystallization rate is slow and the product purity is low, making it difficult to meet the requirements of industrial production. Therefore, an efficient continuous crystallization process for succinic acid is needed. In the existing technology, the main problems include:

[0004] (1) Traditional methods for producing succinic acid have high energy consumption and complex processes, making it difficult to achieve large-scale and continuous production;

[0005] (2) The succinic acid products produced by the microbial fermentation method have relatively low purity and need to further improve their purity and crystallization rate;

[0006] (3) In the existing continuous crystallization processes for succinic acid, the crystallization rate is slow and the product purity is low, making it difficult to meet the requirements of industrial production.

[0007] Therefore, an efficient continuous crystallization process for succinic acid is needed to solve the problems existing in the prior art. Summary of the Invention

[0008] The purpose of the present invention is to provide a continuous crystallization process for high-purity succinic acid to solve the problems raised in the above background art.

[0009] To achieve the above purpose, the present invention provides a continuous crystallization process for high-purity succinic acid, including the following steps:

[0010] S1. Using a butadiene solution as a raw material, promoting its oxidation reaction with oxygen through an acid catalyst to generate a succinic acid solution, and adding a stabilizer to the succinic acid solution;

[0011] S2. Adding the succinic acid solution to a microbial fermentation reactor and adding a microbial strain;

[0012] S3. After pre-cooling the high-concentration succinic acid solution through a heat exchanger, it enters the crystallizer, and succinic acid in the solution crystallizes by cooling in the crystallizer; during the cooling process, by adding a plant regulator, the crystallinity and purity are adjusted;

[0013] S4. During the continuous crystallization process, the produced crystalline product will be filtered, washed, and dried to obtain a high-purity succinic acid crystal product;

[0014] S5. Recover and utilize the solvent remaining in the crystallization product; the solvent is recovered by distillation and reused in the production process of succinic acid.

[0015] Preferably, the plant regulator includes plant extracts, plant oils, and plant acids; the dosage of plant extracts in the plant regulator is 15 - 30 parts by weight, the dosage of plant oils is 30 - 60 parts by weight, and the dosage of plant acids is 2 - 8 parts by weight.

[0016] Preferably, the plant extract is at least one of tea extract, licorice extract, and chrysanthemum extract.

[0017] Preferably, the plant oil is at least one of olive oil, linseed oil, and sunflower oil.

[0018] Preferably, the plant acid is one of malic acid and citric acid.

[0019] Preferably, the stabilizer is one of paraffin acid and benzoic acid.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. In the continuous crystallization process of the high-purity succinic acid, the synergistic effect of the plant extracts, plant oils, and plant acids of the plant regulator is to improve the crystallization rate, size, and purity of succinic acid; they can interact with each other to produce a synergistic effect, such as increasing the crystallization rate and purity, reducing the adsorption of impurities and solvents, etc.; at the same time, they can also improve the yield and selectivity of succinic acid, reduce production costs, and achieve the unity of economic and environmental benefits.

[0022] 2. In the continuous crystallization process of the high-purity succinic acid, organic impurities are converted into harmless substances through a microbial fermentation reactor to improve the yield and selectivity of succinic acid; the cyclic crystallization method is adopted, and the crystallinity and purity are adjusted by a plant regulator to improve the crystallization rate, size, and purity, and reduce production costs; the solvent remaining in the crystallization product is recovered and utilized to achieve recycling and improve the economy and environmental friendliness of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a block diagram of the overall process of the present invention. Detailed implementation mode

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

[0025] According to Figure 1 As shown, the embodiments of the present invention provide a continuous crystallization process for high-purity succinic acid, and the specific steps are as follows:

[0026] (1) Preparation of high-purity solution: Using a butadiene solution as a raw material, an acid catalyst is used to promote its oxidation reaction with oxygen to generate a succinic acid solution.

[0027] A stabilizer is added to the succinic acid solution. The stabilizer is one of paraffin acid and benzoic acid to avoid excessive crystallization and agglomeration of impurities, which is beneficial to the good dispersion of crystallization and the removal of impurities.

[0028] (2) Add the succinic acid solution to a microbial fermentation reactor, add a microbial strain, and through the microbial fermentation reaction, convert the organic impurities in the succinic acid solution into harmless substances, and at the same time improve the yield and selectivity of succinic acid.

[0029] (3) Continuous crystallization: In order to achieve continuous crystallization, a cyclic crystallization method is adopted, preferably cooling crystallization, and the steps are as follows:

[0030] The high-concentration succinic acid solution is pre-cooled by a heat exchanger and then enters the crystallizer. In the crystallizer, the succinic acid in the solution crystallizes by cooling. Through the continuous supply of the coolant and the continuous discharge of the crystallization product, the process of continuous crystallization can be achieved; during the cooling process, by adding a plant regulator, the crystallinity and purity are adjusted.

[0031] The plant regulator includes the following raw materials:

[0032] Plant extract, 15-30 parts by weight;

[0033] Plant oil, 30-60 parts by weight;

[0034] Plant acid, 2-8 parts by weight.

[0035] The plant extract is at least one of tea extract, licorice extract, and chrysanthemum extract; the plant extract can increase the crystallization rate and crystal size, and at the same time can also improve the purity; this is because the various bioactive substances contained in the plant extract, such as flavonoids, flavonoids, triterpenoids, etc., have the effect of promoting crystal growth and inhibiting impurity growth; in addition, the plant extract also contains rich phenolic compounds and nutrients such as vitamins, which can improve the purity of succinic acid.

[0036] The vegetable oil is at least one of olive oil, linseed oil, and sunflower oil. The vegetable oil can prevent caking and excessive crystallization during the crystallization process; this is because the unsaturated fatty acids in the oil can form stable esters with succinic acid, thus preventing crystal caking; in addition, the vegetable oil can also improve the purity of succinic acid because they can form different polar substances with impurities, which are easy to separate and remove.

[0037] The plant acid is one of malic acid and citric acid; the plant acid can adjust the pH value of the solution, thereby increasing the crystallization rate and purity; this is because the carboxyl group in the plant acid can form a stable complex with metal ions in the solution, thereby adjusting the pH value of the solution; in addition, the plant acid can also form a stable carboxylate with succinic acid, thereby promoting crystal formation and growth.

[0038] In the present invention, the synergistic effect of the plant extract, vegetable oil, and plant acid of the plant regulator is to increase the crystallization rate, size, and purity of succinic acid; they can interact with each other to produce a synergistic effect, such as increasing the crystallization rate and purity, reducing the adsorption of impurities and solvents, etc.; at the same time, they can also improve the yield and selectivity of succinic acid, reduce production costs, and achieve the unity of economic and environmental benefits.

[0039] (4) Crystallization product treatment: In the continuous crystallization process, the produced crystallization product will go through steps such as filtration, washing, and drying to remove impurities and solvents, and obtain a high-purity succinic acid crystal product.

[0040] (5) Recycling the solvent: To improve the economy and environmental friendliness of the process, the solvent remaining in the crystallization product is recovered and reused; the solvent is recovered by distillation and reused in the production process of succinic acid to achieve recycling.

[0041] In the present invention, organic impurities are converted into harmless substances through a microbial fermentation reactor to increase the yield and selectivity of succinic acid; a cyclic crystallization method is adopted, and the plant regulator is used to adjust the crystallinity and purity, increase the crystallization rate, size, and purity, and reduce production costs; the solvent remaining in the crystallization product is recovered and reused to achieve recycling and improve the economy and environmental friendliness of the process.

[0042] According to different raw material dosages, the continuous crystallization process of high-purity succinic acid provided by the present invention is further illustrated through the following specific embodiments.

[0043] Example 1

[0044] (1) Preparation of high-purity solution: Using a butadiene solution as the raw material, an oxidation reaction with oxygen is promoted by an acid catalyst to generate a succinic acid solution.

[0045] A stabilizer is added to the succinic acid solution. The stabilizer is one of paraffin acid and benzoic acid to avoid excessive crystallization and agglomeration of impurities, which is beneficial to the good dispersion of crystallization and the removal of impurities.

[0046] (2) Add the succinic acid solution to a microbial fermentation reactor, add a microbial strain, and through the microbial fermentation reaction, convert the organic impurities in the succinic acid solution into harmless substances, while increasing the yield and selectivity of succinic acid.

[0047] (3) Continuous crystallization: The high-concentration succinic acid solution is precooled through a heat exchanger and then enters the crystallizer. In the crystallizer, the succinic acid in the solution crystallizes by cooling. Through the continuous supply of the coolant and the continuous discharge of the crystallization product, the continuous crystallization process can be achieved; during the cooling process, by adding a plant regulator, the crystallinity and purity are adjusted.

[0048] The plant regulator includes the following raw materials:

[0049] Plant extract, 15 parts by weight;

[0050] Plant oil, 30 parts by weight;

[0051] Plant acid, 2 parts by weight.

[0052] The plant extract is tea extract and chrysanthemum extract.

[0053] The plant oil is olive oil and linseed oil.

[0054] The plant acid is malic acid.

[0055] (4) Treatment of crystallization product: During the continuous crystallization process, the generated crystallization product will go through steps such as filtration, washing, and drying to remove impurities and solvents, obtaining a high-purity succinic acid crystal product.

[0056] Example 2

[0057] This example uses the method of Example 1, the difference is that the ratio of the plant regulator is different, and the remaining steps remain unchanged; the raw materials of the plant regulator are as follows:

[0058] Plant extract, 22 parts by weight;

[0059] Vegetable oil, 45 parts by weight;

[0060] Vegetable acid, 5 parts by weight.

[0061] The plant extract uses licorice extract and chrysanthemum extract.

[0062] The vegetable oil uses linseed oil and sunflower oil.

[0063] The vegetable acid uses citric acid.

[0064] Example 3

[0065] This example uses the method of Example 1, the difference is the ratio of the plant regulator is different, and the rest of the steps remain unchanged; the raw materials of the plant regulator are as follows:

[0066] Plant extract, 30 parts by weight;

[0067] Vegetable oil, 60 parts by weight;

[0068] Vegetable acid, 8 parts by weight.

[0069] The plant extract uses tea extract and licorice extract.

[0070] The vegetable oil uses olive oil and sunflower oil.

[0071] The vegetable acid uses citric acid.

[0072] Example 4

[0073] This example uses the method of Example 1, the difference is the ratio of the plant regulator is different, and the rest of the steps remain unchanged; the raw materials of the plant regulator are as follows:

[0074] Plant extract, 20 parts by weight;

[0075] Vegetable oil, 30 parts by weight;

[0076] Vegetable acid, 3 parts by weight.

[0077] The plant extract uses tea extract, licorice extract and chrysanthemum extract.

[0078] The vegetable oil uses olive oil, linseed oil and sunflower oil.

[0079] The vegetable acid uses malic acid.

[0080] Example 5

[0081] This example uses the method of Example 1, the difference is the ratio of the plant regulator is different, and the rest of the steps remain unchanged; the raw materials of the plant regulator are as follows:

[0082] Plant extract, 28 parts by weight;

[0083] Vegetable oil, 55 parts by weight;

[0084] Vegetable acid, 6 parts by weight.

[0085] The plant extract used is licorice extract and chrysanthemum extract.

[0086] The vegetable oil used is linseed oil.

[0087] The vegetable acid used is citric acid.

[0088] Table 1 Proportion of plant regulators in Examples 1-5

[0089]

[0090] In order to verify that the succinic acid crystallization process prepared in the examples of the present invention has high purity and yield, the continuous crystallization process of high-purity succinic acid provided in the examples of the present invention will be described through the following test examples.

[0091] Test Example

[0092] In this test example, the succinic acid crystallization provided in Examples 1-5 was tested for yield and purity, and the specific test indexes are shown in Table 2.

[0093] Table 2

[0094]

[0095]

[0096] As shown in Table 2, for the continuous crystallization process of succinic acid provided in Examples 1-5 of the present invention, the yields are all higher than 95%, and succinic acid crystal products with a purity higher than 99.5% can be obtained. Therefore, it can be shown that in the continuous crystallization process of the present invention, by adding plant regulators to adjust the crystallinity and purity, the crystallization rate, size and purity are improved.

[0097] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A continuous crystallization process for high-purity succinic acid, characterized in that, It includes the following steps: S1. Using a butadiene solution as a raw material, promoting its oxidation reaction with oxygen through an acid catalyst to generate a succinic acid solution, and adding a stabilizer to the succinic acid solution; S2. Adding the succinic acid solution to a microbial fermentation reactor and adding a microbial strain; S3. Pre-cooling the high-concentration succinic acid solution through a heat exchanger and then entering a crystallizer, and crystallizing the succinic acid in the solution by lowering the temperature in the crystallizer; During the cooling process, by adding a plant regulator, the crystallinity and purity are adjusted; S4. During the continuous crystallization process, the crystallized product generated will be filtered, washed, and dried to obtain a high-purity succinic acid crystal product.

2. The continuous crystallization process of high-purity succinic acid according to claim 1, characterized in that: The plant regulator includes plant extracts, plant oils, and plant acids.

3. The continuous crystallization process of high-purity succinic acid according to claim 2, characterized in that: In the plant regulator, the dosage of the plant extract is 15-30 parts by weight, the dosage of the plant oil is 30-60 parts by weight, and the dosage of the plant acid is 2-8 parts by weight.

4. The continuous crystallization process of high-purity succinic acid according to claim 2, characterized in that: The plant extract adopts at least one of tea extract, licorice extract, and chrysanthemum extract.

5. The continuous crystallization process of high-purity succinic acid according to claim 2, characterized in that: The plant oil adopts at least one of olive oil, linseed oil, and sunflower oil.

6. The continuous crystallization process of high-purity succinic acid according to claim 2, characterized in that: The plant acid adopts one of malic acid and citric acid.

7. The continuous crystallization process of high-purity succinic acid according to claim 1, characterized in that: It further includes S5, and the method is: recycling and utilizing the solvent remaining in the crystallization product; recovering the solvent by distillation and reusing it in the production process of succinic acid.

8. The continuous crystallization process of high-purity succinic acid according to claim 1, characterized in that: The stabilizer adopts one of paraffin acid and benzoic acid.

Images