阅读说明：本技术 一种从发酵液中提取分离β-丙氨酸的方法 (Method for extracting and separating beta-alanine from fermentation liquor ) 是由 冯志彬 张娟 程仕伟 张兴晓 刘冬冬 于 2021-01-26 设计创作，主要内容包括：本发明公开了一种从发酵液中提取分离β-丙氨酸的方法,属于生物工程领域。所述方法为(1)发酵液除菌及大分子蛋白；(2)折波滤芯脱色(3)发酵清液经电去离子技术除去无机盐；(4)步骤(3)中清液除去小分子蛋白及部分色素物质；(5)真空浓缩；(6)向浓缩液加入乙醇并降温结晶,获得β-丙氨酸晶体。本发明方法采用折叠滤芯脱色,具有纳污能力强、再生能力强,可反复使用；采用电去离子技术兼具电渗析过程可持续性和离子交换过程脱盐彻底性,并伴随树脂电再生性；采用乙醇降温结晶,具有提取收率高,一次收率可达69％,通过母液回收处理,总收率高达91％以上,并且产品质量明显提高。(The invention discloses a method for extracting and separating beta-alanine from fermentation liquor, belonging to the field of bioengineering. The method comprises the steps of (1) degerming fermentation liquor and removing macromolecular protein; (2) decoloring by a folding filter element (3), and removing inorganic salt from the fermentation clear liquid by an electrodeionization technology; (4) removing small molecular proteins and part of pigment substances from the clear liquid in the step (3); (5) concentrating in vacuum; (6) adding ethanol into the concentrated solution, and cooling and crystallizing to obtain beta-alanine crystals. The method adopts the folding filter element for decolorization, has strong pollutant carrying capacity and regeneration capacity, and can be used repeatedly; the adoption of an electrodeionization technology has the sustainability of an electrodialysis process and the thoroughness of desalination of an ion exchange process, and is accompanied with the electrical regeneration of resin; the ethanol is adopted for cooling crystallization, the extraction yield is high, the primary yield can reach 69 percent, the total yield can reach more than 91 percent through the recovery treatment of the mother liquor, and the product quality is obviously improved.)

1. A method for extracting and separating beta-alanine from fermentation liquor is characterized by comprising the following steps:

(1) removing thalli from fermentation liquor: passing the fermentation liquor containing beta-alanine through a microfiltration membrane with the molecular weight cutoff of 100nm to thoroughly remove thalli and macromolecular protein in the fermentation liquor to obtain a beta-alanine fermentation clear liquid; the microfiltration operation pressure is 0.4MPa, the microfiltration operation temperature is 20-30 ℃, and the microfiltration water accounts for 10-80% of the volume of the feed fermentation liquor in percentage by volume;

(2) and (3) decoloring: decolorizing the beta-alanine fermentation clear liquid obtained in the step (1) by a folding filter element, wherein the temperature of the beta-alanine solution is 40-80 ℃, the pressure is 0.05-0.4MPa, and the effluent liquid is the decolorized clear liquid;

(3) desalting by an electrodeionization technology: adjusting the conductivity of the decolorized clear liquid obtained in the step (2) to 10-50mS/cm, adjusting the pH value to 5-7 at an isoelectric point, performing electrodialysis and ion exchange resin coupling device, namely an EDI device, mixing and filling cation and anion resin into a fresh room of the EDI device according to the volume ratio of 1:2-2:1, wherein the operation temperature is 10-50 ℃, the water volume of the decolorized clear liquid in a concentrated room is 0.5-3 times that of the decolorized clear liquid, the conductivity ratio of the fresh room to the concentrated room is kept within 15 times, continuously operating at the voltage of 20-60V, stopping operating when the conductivity of the fresh room reaches below 1mS/cm, obtaining desalted clear liquid, and the loss rate of beta-alanine is within 5%;

(4) removing small molecular proteins and partial pigments in the desalted clear liquid: removing small molecular proteins and partial pigment substances from the beta-alanine desalted clear liquid obtained in the step (3) through a nanofiltration membrane with the shutoff value of 500-3000D to obtain a transparent and colorless beta-alanine solution, wherein the operation pressure is 0.5-3MPa, the operation temperature is 10-60 ℃, and the nanofiltration water amount accounts for 10-80% of the volume of the feed fermentation liquid in percentage by volume;

(5) and (3) concentrating fermentation liquor: carrying out vacuum concentration on the beta-alanine solution obtained in the step (4), wherein the vacuum degree is 0.05-0.1MPa, and the temperature of the beta-alanine solution is 50-90 ℃, so as to obtain 60% -90% of a solid content of a concentrated solution;

(6) cooling and crystallizing ethanol: adding ethanol with the volume of 50-90% of that of the concentrated solution into the concentrated solution obtained in the step (5), cooling to 5-30 ℃ to crystallize and separate out beta-alanine, and centrifuging to collect separated crystals;

(7) and (3) drying: drying the centrifuged beta-alanine to obtain a finished product.

2. The method according to claim 1, wherein the beta-alanine fermentation broth of step (1) is obtained in the following fermentation process for the production of beta-alanine:

1) seed culture: washing the inclined plane of Escherichia coli ZF009 with sterile water, inoculating into self-controlled fermentation tank containing seed culture medium, respectively controlling culture temperature at 37 deg.C, pH at 7.0, maintaining dissolved oxygen at 18-22%, and culturing for 10 hr;

2) fermentation culture: inoculating the mature seeds cultured in the step 1) into an automatic control fermentation tank filled with a fermentation culture medium according to the seed amount of 5 percent by volume, wherein the initial fermentation temperature is 37 ℃, the pH value is 7.0, the dissolved oxygen is maintained at 20 percent by adjusting the ventilation volume, the rotating speed and the tank pressure, and the OD of the optical density value of the thallus is obtained₆₀₀When the pH value reaches 10, stopping introducing the gas, fixing the stirring speed at 200r/min, continuously culturing under the anaerobic condition, and adjusting the pH value to 7.0; when the initial sugar concentration is reduced to 5g/L, feeding 500g/L glucose to maintain the glucose concentration at 5g/L, and ending the fermentation for 42h to obtain beta-alanine fermentation liquor;

the components and final concentration of the fermentation medium are 30-80g/L of glucose, 5-10g/L of ammonium chloride and 5-20g/L, KH of cane molasses₂PO₄1-5g/L、MgSO₄1-3g/L, 0-10g/L yeast extract powder, 0-10g/L bran hydrolysate, 0-10g/L corn steep liquor, 0-20g/L thallus hydrolysate, 50-200 mug/L, DL biotin-0.1-2 g/L, L-threonine 0.1-2g/L, nicotinamide 1-10mg/L, vitamin B₁1-10mg/L、ZnSO₄1-10mg/L and CoCl₂ 1-10mg/L；

The preparation method of the thallus hydrolysate comprises the following steps: collecting Escherichia coli ZF009, oven drying at 80 deg.C to constant weight, preparing bacterial suspension at concentration of 100g/L, adjusting pH to 10.0 with NaOH, and hydrolyzing at 120 deg.C for 5 hr; the Escherichia coli ZF009 is preserved in the China general microbiological culture Collection center in 2019, 5 months and 20 days, and the biological preservation number is CGMCC NO: 17830.

3. the method according to claim 1, characterized in that the ultrafiltration membrane of step (1) has a molecular weight cut-off of 100nm, an operating pressure of 0.2-0.5MPa, an operating temperature of 20-30 ℃ and an ultrafiltration water amount of 10-80% by volume of the feed fermentation broth.

4. The method according to claim 1, wherein the beta-alanine fermentation clear liquid obtained in the step (2) is decolorized by a folding filter element, and the effluent liquid is the decolorized clear liquid when the temperature of the beta-alanine solution is 60-80 ℃ and the pressure is 0.1-0.3 MPa.

5. The method according to claim 1, wherein in the step (3), the EDI device is used, the volume ratio of the anion resin to the cation resin is 1:1, the conductivity of the beta-alanine stock solution is 10-50mS/cm, the pH value is 5.5-6.5, the EDI device is used, the operation temperature is 20-30 ℃, the water adding amount of a dense chamber is 0.5-2 times of the volume of fermentation decolorized clear solution, the conductivity of a weak chamber is kept within 15 times of the conductivity ratio of the dense chamber, the EDI device is continuously operated at a voltage of 30-40V, the EDI device is stopped when the conductivity of the weak chamber reaches below 1mS/cm, and the loss rate of the beta-alanine is within 5 percent.

6. The method as claimed in claim 1, wherein the nanofiltration membrane of step (4) has a molecular weight cut-off of 500-.

7. The method according to claim 1, wherein the step (6) of adding ethanol to the concentrate in an amount of 60 to 80% by volume of the concentrate and cooling the mixture to a temperature of 10 to 20 ℃.

Technical Field

The invention relates to a method for extracting and separating beta-alanine from fermentation liquor, in particular to an extraction and separation method for removing inorganic salt and ethanol crystals in beta-alanine fermentation liquor by using an electrodeionization technology, belonging to the field of bioengineering.

Background

Beta-alanine is the only beta-amino acid in nature, a non-protein amino acid, and in vivo, beta-alanine is not involved in protein and enzyme synthesis, belongs to non-protein amino acid, but is a potential functional amino acid. Beta-alanine is a precursor of various substances, and has wide application in the aspects of medicines, foods, chemical industry, feeds and the like, for example, in the field of medicines, beta-alanine is mainly used for synthesizing pantothenic acid and calcium pantothenate, is a precursor of Acyl Carrier Protein (ACP) and coenzyme A (CoA), and plays an important physiological function in helping cell regeneration, assisting the normal development process of the central nervous system and participating in the metabolism of proteins, fats and sugars in vivo. It is one of the 12 most potential products of the three-carbon industry.

At present, the methods for producing beta-alanine at home and abroad comprise a chemical method, an enzyme conversion method and a fermentation method. The chemical method has complicated process, high energy consumption and serious environmental pollution; the enzyme conversion method has the defects of high substrate cost and non-regeneration; because of the increasing severity of climate change and environmental problems caused by fuel consumption in recent years, people are more and more concerned about exploring clean and environment-friendly production methods such as direct fermentation, the fermentation yield of beta-alanine is improved to about 65g/L at present, and in order to meet the requirements of pilot-scale and large-scale fermentation production, the production process of extracting and refining beta-alanine from fermentation liquor needs to be researched.

The amino acid fermentation liquor contains various substances, such as products, byproducts, culture medium residual substances, thalli and the like, the extraction and separation of the fermentation products occupy an extremely important position in production, and other impurities except the products in the fermentation liquor are required to be removed in the extraction process so as to obtain high-quality products. At present, the production method of beta-alanine is mainly an enzyme conversion method, and conversion solution only contains trace inorganic salt without desalting; the fermentation liquor contains various inorganic salts and has high content, desalting treatment is required, ion exchange resin is used independently, resin pollution is serious, the resin structure is damaged, the regeneration capacity is lost, meanwhile, the resin can quickly reach saturation due to high-content ionic substances, the resin can be continuously used after regeneration, and the problems of operation cost, sewage discharge and the like are solved. The desalting effect can be realized by using electrodialysis alone, but the desalting time is long, and particularly the later desalting speed is very slow.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for extracting beta-alanine from fermentation liquor.

The invention is realized by the following technical scheme:

a method for extracting and separating beta-alanine from fermentation liquor comprises the following specific steps:

(1) removing thalli from fermentation liquor: passing the fermentation liquor containing beta-alanine through a microfiltration membrane with the molecular weight cutoff of 100nm to thoroughly remove thalli and macromolecular protein in the fermentation liquor to obtain a beta-alanine fermentation clear liquid; the operation pressure is 0.4MPa, the operation temperature is 20-30 ℃, and the dialyzed water accounts for 10-80% of the volume of the feed fermentation liquor in percentage by volume;

(2) and (3) decoloring: decolorizing the beta-alanine fermentation clear liquid obtained in the step (1) by a folding filter element, wherein the temperature of the beta-alanine solution is 40-80 ℃, the pressure is 0.05-0.4MPa, and the effluent liquid is the decolorized clear liquid;

(3) desalting by an electrodeionization technology: adjusting the conductivity of the decolorized clear liquid obtained in the step (2) to 10-50mS/cm, adjusting the pH value to 5-7 at an isoelectric point, performing electrodialysis and ion exchange resin coupling device, namely an EDI device, mixing and filling cation and anion resin into a fresh room of the EDI device according to the volume ratio of 1:2-2:1, wherein the operation temperature is 10-50 ℃, the water volume of the decolorized clear liquid in a concentrated room is 0.5-3 times that of the decolorized clear liquid, the conductivity ratio of the fresh room to the concentrated room is kept within 15 times, continuously operating at the voltage of 20-60V, stopping operating when the conductivity of the fresh room reaches below 1mS/cm, obtaining desalted clear liquid, and the loss rate of beta-alanine is within 5%;

(4) removing small molecular proteins and partial pigments in the desalted clear liquid: removing small molecular proteins and partial pigment substances from the beta-alanine desalination clear solution obtained in the step (3) by a nanofiltration membrane with the shutoff value of 500-3000D to obtain a transparent and colorless beta-alanine solution, wherein the operation pressure is 0.5-3MPa, the operation temperature is 10-60 ℃, and the dialysis water accounts for 10-80% of the volume of the feed fermentation liquid in percentage by volume;

(5) and (3) concentrating fermentation liquor: carrying out vacuum concentration on the beta-alanine solution obtained in the step (4), wherein the vacuum degree is 0.05-0.1MPa, the temperature of the beta-alanine solution is 50-90 ℃, the solid content of the obtained concentrated solution is 60% -90%, and distilled pure water is used for water for the production process;

(6) cooling and crystallizing ethanol: adding ethanol with the volume of 50-90% of that of the concentrated solution into the concentrated solution, then cooling to 5-30 ℃ to crystallize and separate out beta-alanine, and centrifugally collecting separated crystals; (7) and (3) drying: drying the centrifuged beta-alanine to obtain a finished product.

Further, the beta-alanine fermentation liquor in the step (1) is a process for producing beta-alanine by fermentation in the following steps:

1) seed culture: washing the engineering bacteria inclined plane of the escherichia coli by sterile water, inoculating the engineering bacteria inclined plane into a self-control fermentation tank filled with a seed culture medium, respectively controlling the culture temperature and the pH to be 37 ℃ and 7.0, maintaining the dissolved oxygen to be 18-22%, and culturing for 10 hours;

2) fermentation culture: inoculating the mature seeds cultured in the step 1) into a 10L self-control fermentation tank filled with 6L fermentation medium according to the seed amount of 5%, wherein the initial fermentation temperature is 37 ℃, the pH value is 7.0, the dissolved oxygen is maintained at about 20% by adjusting the ventilation volume, the rotation speed and the tank pressure, and the OD of the optical density value of the thallus is obtained₆₀₀When the pH value reaches 10, stopping introducing the gas, fixing the stirring speed at 200r/min, continuously culturing under the anaerobic condition, and controlling the pH value to be 7.0 by using a pH regulator; when the initial sugar concentration is reduced to 5g/L, feeding 500g/L glucose to maintain the glucose concentration at about 5g/L, and ending the fermentation for 42h to obtain beta-alanine fermentation liquor; the components and final concentration of the fermentation medium are 30-80g/L of glucose, 5-10g/L of ammonium chloride and 5-20g/L, KH of cane molasses₂PO₄ 1-5 g/L、MgSO₄1-3g/L, 0-10g/L yeast extract powder, 0-10g/L bran hydrolysate, 0-10g/L corn steep liquor, 0-20g/L thallus hydrolysate, 50-200 mug/L, DL biotin-0.1-2 g/L, L-threonine 0.1-2g/L, nicotinamide 1-10mg/L, vitamin B₁ 1-10mg/L、ZnSO₄1-10mg/L and CoCl₂ 1-10mg/L；

The preparation method of the thallus hydrolysate comprises the following steps: collecting Escherichia coli ZF009, drying at 80 ℃ to constant weight, preparing bacterial suspension according to the concentration of 100g/L, adjusting the pH to 10.0 by NaOH, hydrolyzing for 5h at 120 ℃, and storing the Escherichia coli ZF009 in the China general microbiological culture Collection center in 2019, 5 months and 20 days, wherein the biological preservation number is CGMCC NO: 17830. (Escherichia coli ZF009, first published 24.9.2019, patent No. 2019104747539, patent name beta-alanine producing bacterium, preparation method and use thereof).

Further, the ultrafiltration membrane in the step (1) has the molecular weight cutoff of 100nm, the operation pressure of 0.2-0.5MPa is preferred, the operation temperature of 20-30 ℃ is preferred, and the dialyzed water accounts for 10-80% of the volume of the fed fermentation liquor in percentage by volume.

Further, decoloring the beta-alanine fermentation clear liquid in the step (2) by a folding filter element, wherein the beta-alanine solution is preferably 60-80 ℃ at the temperature and 0.1-0.3MPa, and the effluent liquid is the decolored clear liquid; further, according to the EDI device in the step (3), the volume ratio of the anion resin to the cation resin is 1:1, the conductivity of the beta-alanine stock solution is 10-50mS/cm, the pH value is 5.5-6.5, the EDI device is used, the operation temperature is preferably 20-30 ℃, the water adding amount of a dense chamber is 0.5-2 times of the volume of the fermented decolorized clear solution, the conductivity of the dilute chamber is kept within 15 times of that of the dense chamber, the EDI device is continuously operated under the voltage of 30-40V, the operation is stopped when the conductivity of the dilute chamber reaches below 1mS/cm, and the loss rate of the beta-alanine is within 5%. The molecular weight cut-off of the nanofiltration membrane in the step (4) is 500-1000D, the operation pressure is preferably 0.5-2MPa, the operation temperature is preferably 20-30 ℃, and the dialyzed water accounts for 10-80% of the volume of the fed fermentation liquid in percentage by volume.

And (3) carrying out vacuum concentration on the beta-alanine solution obtained in the step (5) (the vacuum degree is 0.05-0.1MPa, and the temperature of the beta-alanine solution is 50-90 ℃), wherein the solid content of the obtained concentrated solution is 60% -90%, and distilling out pure water for producing process water. And (4) adding ethanol with the volume of 60-80% of the concentrated solution into the concentrated solution in the step (6), and cooling to 10-20 ℃.

Compared with the prior art, the invention has the beneficial effects that:

(1) the method for decoloring the fermentation liquor by using the folding filter element and desalting, extracting and separating the beta-alanine from the fermentation liquor can be repeatedly used, has strong regeneration capacity, does not need to manually add activated carbon, and has clean environment.

(2) The invention introduces the electrodeionization technology into the fermentation liquor for the first time to separate and extract the beta-alanine, replaces the electrodialysis technology, and combines the ethanol cooling crystallization method to obtain the beta-alanine. Overcomes the defects of low recovery rate, large sewage discharge, high production strength and the like in the prior art. The desalination time and desalination rate of the two techniques were compared: under the same desalting time, the desalting removal rate is respectively 98.9 percent and 96.4 percent; when the desalting rate is the same (98.9%), the desalting time is 106min and 132min respectively, so that the yield and the product quality of the beta-alanine are improved.

(3) The beta-alanine is obtained by adopting microfiltration for sterilization and macromolecular substances, decoloring by a folding wave filter core to remove pigments, desalting by an electrodeionization technology, concentrating the desorption solution by double-effect concentration, and finally cooling and crystallizing. The method has the advantages of remarkable desalting effect of the fermentation liquor, high extraction yield, primary yield of 69 percent and total extraction rate of 92 percent by recovering and treating the mother liquor. The method of the invention is easy to realize industrialization, has relatively low extraction cost and high product quality, and can be used for large-scale treatment.

(4) The conventional technology of ion exchange is replaced by the electrodeionization technology: the water consumption of the former is at most 4 times of the volume of the fermentation liquor, and the water consumption of the ion exchange resin needs to be increased to 10 times of the volume of the fermentation liquor due to regeneration and elution, and a large amount of sewage is generated at the same time, so that the sewage treatment cost is increased.

(5) The ethanol is adopted for cooling to replace the traditional cooling crystallization of beta-alanine, the primary extraction rate is improved by 15 percent, and the total extraction rate is improved by 20 percent.

Detailed Description

The following example is a method for extracting beta-alanine from fermentation broth of Escherichia coli ZF009 containing beta-alanine, which was extracted from fermentation broth obtained with a fermentative species.

Example 1

The method for producing the beta-alanine by the beta-alanine fermentation liquor comprises the following steps:

the bran hydrolysate and corn steep liquor are purchased from Shandongyang Biotech limited.

The preparation method of the thallus hydrolysate comprises the following steps: the preparation method of the thallus hydrolysate comprises the following steps: collecting Escherichia coli ZF009, drying at 80 ℃ to constant weight, preparing bacterial suspension according to the concentration of 100g/L, adjusting the pH to 10.0 by NaOH, hydrolyzing for 5h at 120 ℃, and storing the Escherichia coli ZF009 in the China general microbiological culture Collection center in 2019, 5 months and 20 days, wherein the biological preservation number is CGMCC NO: 17830. (Escherichia coli ZF009, first published 24.9.2019, patent No. 2019104747539, patent name beta-alanine producing bacterium, preparation method and use thereof).

Other reagents were all commercially available.

1) Seed culture: washing engineering bacteria slant of Escherichia coli with sterile water, inoculating into 5L self-controlled fermentation tank containing 3L seed culture medium, controlling culture temperature and pH at 37 deg.C and 7.0 respectively, maintaining dissolved oxygen at about 20%, and culturing for 10 hr.

2) Fermentation culture: inoculating the mature seeds cultured in the step 1) into a 10L self-control fermentation tank filled with 6L fermentation medium according to the seed amount of 5%, wherein the initial fermentation temperature is 37 ℃, the pH value is 7.0, the dissolved oxygen is maintained at about 20% by adjusting the ventilation volume, the rotation speed and the tank pressure, and the OD of the optical density value of the thallus is obtained₆₀₀When the pH value reaches 10, stopping introducing the gas, fixing the stirring speed at 200r/min, continuously culturing under the anaerobic condition, and controlling the pH value to be 7.0 by using a pH regulator; when the initial sugar concentration is reduced to 5g/L, 500g/L of glucose is fed in to maintain the glucose concentration at about 5g/L, the fermentation is finished within 42 hours, the beta-alanine concentration is 75.6g/L, and the sugar-acid conversion rate is 66.2%. Wherein the fermentation medium is: 80g/L glucose, 10g/L cane molasses and 10g/L, KH ammonium chloride₂PO₄ 3g/L、MgSO₄ 1g/L、Thallus Hydrolysate of 20g/L3g/L of corn steep liquor, 100 mu g/L, DL-methionine 0.1g/L, L-threonine 0.1g/L of biotin, 5mg/L of nicotinamide and vitamin B₁ 5mg/L、ZnSO₄ 2mg/L、CoCl₂ 2mg/L。

The method for extracting the beta-alanine from the beta-alanine fermentation liquor comprises the following steps:

(1) removing thalli from fermentation liquor: and (3) passing the fermentation liquor containing the beta-alanine through a microfiltration membrane with the molecular weight cutoff of 100nm to completely remove thalli and macromolecular protein in the fermentation liquor to obtain a beta-alanine fermentation clear liquid. The operation pressure is 0.4MPa, the operation temperature is 20-30 ℃, and the dialyzed water accounts for 10-80% of the volume of the feed fermentation liquor in percentage by volume.

(2) And (3) decoloring: and (3) decolorizing the beta-alanine fermentation clear liquid obtained after sterilization by a folding filter element, wherein the temperature of the beta-alanine solution is 60 ℃, and the pressure is 0.3MPa, and the effluent liquid is the decolorized clear liquid.

(3) Desalting by an electrodeionization technology: the beta-alanine fermentation decolorization clear liquid obtained by folding the filter element is adjusted to the isoelectric point pH 6, and is subjected to electrodialysis and ion exchange resin coupling device (EDI device, wherein anion and cation resin are mixed and filled into a fresh room of the EDI device according to the volume ratio of 1: 1), the operation temperature is 30 ℃, the water addition amount of a dense room is 0.5-3 times of the volume of the fermentation decolorization clear liquid, the conductivity of the fresh room is kept within 15 times of the conductivity ratio of the dense room, the operation is continuously carried out under the voltage of 30V, the operation is stopped when the conductivity of the fresh room reaches below 1mS/cm, and the loss rate is within 5%.

(4) Removing small molecular proteins and partial pigments in the desalted clear liquid: removing small molecular proteins and partial pigment substances from the obtained beta-alanine desalted clear liquid through a nanofiltration membrane with the shutoff value of 500D to obtain a transparent and colorless beta-alanine solution, wherein the operating pressure is 1.2MPa, the operating temperature is 30 ℃, and the dialyzing water accounts for 10-80% of the volume of the fed fermentation liquid in percentage by volume.

(5) And (3) concentrating fermentation liquor: and (3) carrying out vacuum concentration on the beta-alanine solution obtained in the step (4) (the vacuum degree is-0.1 MPa, and the temperature of the beta-alanine solution is 65 ℃), wherein the solid content of the obtained concentrated solution is 65%, and distilled pure water is used for production process water.

(6) Cooling and crystallizing ethanol: adding 60% ethanol of the volume of the concentrated solution into the concentrated solution, then cooling to 10 ℃ to crystallize and separate out beta-alanine, and centrifuging to collect separated crystals.

(7) And (3) drying: the centrifuged beta-alanine was dried to obtain the final product results as shown in table 1.

TABLE 1

Example 2

On the basis of example 1, the beta-alanine solution feed temperature in step (2) was set to 80 ℃ and the results are shown in Table 2:

TABLE 2

Example 3

Based on example 2, step (3) of mixing and filling the anion-cation resin into a light chamber of an EDI device according to the volume ratio of 2:1, and the results are shown in Table 3:

TABLE 3

Example 4

Based on example 2, step (6) added 80% ethanol to the concentrate by volume, the results are shown in Table 4:

TABLE 4

Example 5

After 17 repeated uses of the pleated filter element in step (2) based on example 4, the results are shown in table 5:

TABLE 5