CN105541528A - Method of preparing amino acid from liquor vinasse - Google Patents

Abstract

The invention relates to recovery and treatment of protein in liquor distiller's grains and a method for separating and purifying specific amino acids, and belongs to the technical field of liquor distiller's grain treatment in liquor production. The invention includes the steps of pretreatment of liquor distiller's grains, alcohol extraction of liquor distiller's grains, acid hydrolysis of liquor distiller's grains, neutralization of filtrate, decolorization of activated carbon, extraction of amino acids, ultrafiltration, nanofiltration and concentrated drying, and can convert protein in liquor distiller's grains Amino acids are used to obtain amino acids with high value, effectively treat the distiller's grains in liquor production, and at the same time effectively use the solid waste in the production process of liquor enterprises, so that liquor enterprises can obtain It has certain economic benefits and has high marketing value. The method can save a large amount of extraction reagents, and while not introducing new substances, can also minimize process equipment and process costs, and has high product quality, which is suitable for industrial promotion.

Description

A method for preparing amino acid from liquor distiller's grains

technical field

The invention relates to a method for preparing amino acids by using distiller's grains of liquor, more specifically, the invention relates to the recovery and treatment of protein in distiller's grains of liquor and a method for separating and purifying specific amino acids, which belongs to the technical field of processing distiller's grains of liquor in liquor production.

Background technique

my country is the world's largest producer and consumer of liquor. It is a major brewing country with the most complete varieties of liquor, the longest brewing history, and the largest production scale. It has also realized the transition from traditional small workshops to large-scale ecological brewing processes. my country's liquor industry is particularly remarkable in terms of enterprise scale, product output, product efficiency and social contribution. According to the data released by the National Bureau of Statistics and the China Alcoholic Drinks Association: In 2014, there were 2,602 enterprises above designated size in my country's brewing industry, with a total brewing output of 75.283 million kiloliters, product sales revenue of 877.805 billion yuan, and a total product profit of 97.617 billion yuan. In some places, the liquor industry has also become the main support point for local economic development, and has received policy support from the local government, such as Luzhou, Yibin and Huairen.

However, a large amount of by-product distiller's grains can be produced in the production process of liquor brewing. According to statistics, about three to five tons of distiller's grains are produced for every ton of liquor produced. It is easy to pollute the environment and other characteristics, which seriously restricts the extraction and application research of high-value substances in distiller's grains. In our country, distiller's grains are used for the production of feed raw materials and direct feeding of livestock and poultry; the second is gasification to produce new energy; the third is to produce organic compound fertilizers and mushrooms; the fourth is to be burned and discarded as fuel. Among them, the main use is as agricultural feed and agricultural fuel, which greatly reduces its use value, resulting in the low utilization rate of distiller's grains and low direct economic value in the liquor industry.

In fact, in addition to a large amount of water, liquor distillers grains also contain rich cellulose and hemicellulose, protein and a large amount of amino acids, acids, esters, alcohols, carbonyl compounds and other organic substances and other inorganic substances. Good renewable raw materials can be widely used in food, chemical, textile, printing, medical and health industries, and have very high practical value and research value, and the content analysis further shows that the protein and amino acid content in fresh distiller's grains is as high as 15% , is one of the three main components of liquor distillers grains, if not utilized, it will lead to great waste of raw materials. This method proposes to use alcohol to pre-extract free amino acids and acid hydrolysis distiller's grain protein to prepare compound amino acids with relatively complete composition content, and then use molecularly imprinted polymers to extract specific amino acids to obtain certain varieties of more pure amino acids.

The State Intellectual Property Office disclosed an invention with the publication number CN104689106A titled "A Method for Extracting Free Amino Acids" on 2015.6.10. The invention relates to a method for extracting free amino acids, which includes the following steps: Body pretreatment, solvent extraction, ethanol impurity removal, precipitation dissolution, filtration to remove fat, filtration to volume, decolorization and other steps. It is characterized in that: fresh amino acid donors are rinsed, dried, cut into small pieces, pulverized and filtered, then refluxed in a water bath at 50-90°C for 1-5 hours, and the alcohol concentration in the extract is adjusted to 75%, and then precipitated to remove water-soluble Sexual polysaccharides and proteins, hot water to dissolve the precipitate, filter out the fat, the filtrate was constant volume, decolorized with activated carbon to obtain the free amino acid extract. The invention adopts the method of reflux extraction, which is simple to operate, simple to make and requires less sample, does not destroy the structure of amino acids, and can obtain a solution with a free amino acid content of 8.24 mg/g. The invention adopts the technical route of water reflux extraction, ethanol precipitation, hot water dissolution and filtration, activated carbon decolorization and impurity removal to process plants or vegetables, and obtains a variety of amino acid solutions. The amino acid concentration and composition in the obtained solution are greatly affected by the fluctuation of raw materials, and the product quality cannot be effectively guaranteed; there is also a small amount of ethanol in the obtained amino acid solution, which has certain potential safety hazards and needs further processing.

On September 13, 1995, the State Intellectual Property Office published an invention with the publication number CN1108305A and titled "A Process for Producing Amino Acids by Fermentation". The main raw materials include adding vegetable oil, ammonium bicarbonate, and potassium dihydrogen phosphate, stirring evenly, adding hydrochloric acid, stirring, and adjusting the pH value to 1-2. Even if it is packed in bags, fermentation is carried out. After 12 days, add NaOH, stir to adjust the pH value to pH 6, leave it for 12 hours, and carry out solid-liquid separation to obtain an extract containing amino acids. The inventive process produces high content of amino acid products, including 19% of amino acid and 4% of humic acid. The cost is low, the process is simple, and distiller's grains are used as the main raw material, which has good economic and social benefits. However, this method is greatly affected by environmental conditions, and its operability is poor. A large amount of organic and inorganic substances are added in the process, and the equipment requirements are relatively high. The amino acid solution obtained has complex components, low purity, and difficult purification. limits.

Contents of the invention

The present invention aims to solve the aforementioned problems in the process of extracting amino acids, and provides a method for preparing amino acids by using distiller's grains of liquor. The method comprehensively extracts and utilizes free amino acids and proteins in distiller's grains of liquor, and can directly extract free amino acids in distiller's grains of liquor And convert protein into amino acid to obtain amino acid solution with higher purity, so as to achieve the purpose of reusing amino acid and protein in liquor distiller's grains. The method can save a large amount of extraction reagents, and while not introducing new substances, can also minimize process equipment and process costs, and has high product quality, which is suitable for industrial promotion.

In order to realize the above-mentioned purpose of the invention, its concrete technical scheme is as follows:

A method for preparing amino acids from distiller's grains, characterized in that it comprises the following process steps:

A. Pretreatment of liquor distiller's grains

Pretreating distiller's grains of liquor to obtain pretreated distiller's grains of liquor;

B. Alcoholic extraction of liquor distiller's grains

ultrasonically ultrasonicating the pretreated distiller's grains in step A in 45-85% alcohol solution, and filtering to obtain filtrate and filter residue;

C. Acid hydrolysis of liquor lees

After the filter residue obtained in step B is centrifuged and dried, the acid concentration is 2-6mol/L, the mass-volume ratio of solid to liquid is 1:8-50 (the mass-volume ratio of filter residue to acid liquid, that is, g/ml), and the temperature is 80- Under the conditions of 140°C and 1-12h, hydrolyze and filter to obtain the filtrate;

D. Filtrate neutralization

Mix the filtrate obtained in step B and step C, and add an alkaline solution to neutralize the mixed filtrate after it is cooled to 30°C, adjust the pH value of the solution to 3.0-6.0, precipitate and centrifuge to obtain filtrate and precipitate, and wash the precipitate with an appropriate amount of water Obtain the filtrate, then these two filtrates are mixed to obtain the neutralized filtrate;

E. Activated carbon decolorization

Adjusting the pH value of the neutralized filtrate obtained in step D, so that the pH value of the neutralized filtrate is 3.0-7.0, and then performing activated carbon decolorization treatment to obtain a decolorized solution;

F. Extraction of amino acids

Utilize acrylonitrile (AN) monomers and acrylic acid (AA) monomers to polymerize to obtain PAN polymers, and then template amino acids and PAN polymers at a mass ratio of 1:25-50 (template amino acids and PAN polymers The mass ratio of g/g) is heated and dissolved in a solvent to obtain a polymer solution; it is also possible to directly polymerize acrylonitrile (AN) monomers, acrylic acid (AA) monomers, and template amino acids, and then heat and dissolve the polymers in Obtain a polymer solution in a solvent; then perform ultrasonication at a stirring rate of 30-80r/min, continue stirring for 15-60min, and make it into a specific shape, and freeze-dry at low temperature to wash off the template amino acid, and freeze-dry at low temperature Obtain amino acid extraction polymer, standby;

Soak the amino acid extraction polymer in the decolorization solution obtained in step E, take it out after 1-6 hours, wash the amino acid in the amino acid extraction polymer with ethanol or deionized water, and collect the washing solution and residual liquid;

G. Ultrafiltration and nanofiltration

Both the washing solution and the raffinate obtained in step F are purified by ultrafiltration and nanofiltration to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate;

H. Concentrated and dried

The ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively subjected to low-temperature vacuum concentration treatment, then dried, pulverized, and packaged to obtain specific types of amino acid products and compound amino acid products respectively.

The above-mentioned method for preparing amino acids from distiller's grains is a basic technical solution, and the steps of pretreatment, ultrafiltration and nanofiltration, and concentration and drying of distiller's distiller's grains can be carried out using conventional technical means in the field. More preferably, the following technical solutions can be used:

In step A of the present invention, the pretreatment of the liquor distiller's grains specifically includes: centrifuging the fresh liquor distiller's grains at room temperature for 15-30 minutes under the condition of 200-3000 r/min, drying or drying, sieving to remove impurities, and then Ultrasonic cleaning of liquor distiller's grains at room temperature for 15-60 minutes, the mass-volume ratio of material to liquid is 1:5-20 (the mass ratio of dry liquor distiller's grains to deionized water volume, that is, g/ml), and then centrifuged at room temperature at 200-3000r/min Filter after 15-30 minutes, dry or air-dry the filter residue until its moisture content is 3-8%, then crush the dried or air-dried distiller's grains, and sieve to a fineness of 20-80 mesh for later use.

In the step B of the present invention, the alcohol extraction of the distiller's grains of the liquor is specifically: the liquor distillers grains that have been pretreated in the step A are heated at a temperature of 25-85°C and an alcohol solution concentration of 45-85% (the percentage of the alcohol volume to the total volume) , ie ml/ml), under the condition of stirring speed of 100-300r/min, ultrasonic wave with power of 120-200W for 15-60min, and then filter to obtain filtrate and filter residue.

In step D of the present invention, the neutralization of the filtrate specifically includes: mixing the filtrate obtained in step B and step C, detecting the pH value of the mixed filtrate, and then using 11- Adjust the pH value to 3.0-6.0 by adding and stirring the milk of lime solution at 15 ° Bé, and filter it after standing for 30-90 minutes to obtain filtrate and precipitate, and the volume ratio of material to liquid for the precipitate is 1:6- 10% deionized water (precipitate volume to deionized water volume ratio, ie ml/ml) was washed to obtain a filtrate, and then the two filtrates were mixed to obtain a neutralized filtrate.

In step E of the present invention, the decolorization of activated carbon is specifically: adding 3-10% activated carbon to the neutralization filtrate obtained in step D (the mass of activated carbon accounts for the percentage of the volume of the neutralization filtrate, i.e. g/ml), adjusting The pH value of the neutralized filtrate is 3.0-7.0, the temperature is 50-80° C., and the decolorization is stirred for 30-120 minutes under the condition of 100-300 r/min to obtain a decolorization liquid.

In step F of the present invention, the low-temperature freeze-drying parameters described twice are vacuum degree 0.1-10 Pa, temperature minus 85-minus 55° C., and time 4-24 hours.

In step G of the present invention, the ultrafiltration and nanofiltration treatment specifically includes: using an ultrafiltration membrane with a molecular weight cut-off of 1500-20000 and a nanofiltration membrane with a molecular weight cut-off of 100-800, at an operating pressure of 0.6 -2.0 MPa, under the condition of filtration temperature of 30-70°C, perform cross-flow ultrafiltration and nanofiltration on the washing solution and raffinate obtained in step F, to obtain ultrafiltration and nanofiltration washing solution and ultrafiltration and nanofiltration raffinate.

In the step H of the present invention, the concentrated drying is specifically: the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residue obtained in the step G are respectively placed in a vacuum with a degree of vacuum of 0.08-0.1Mpa and a temperature of 60-90°C. Carry out vacuum concentration treatment for 30-60min under the conditions, so that the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid are respectively concentrated to 1/2-1/6 of their original volumes, and the specific types of amino acid concentrates and compound amino acids are respectively obtained Concentrate; then vacuum-dried at 60-90°C until the moisture content is 3-8%, crushed and packaged to obtain specific types of amino acid products and compound amino acid products.

In step C of the present invention, the acid is one of sulfuric acid or hydrochloric acid or two of them in any ratio.

In step D of the present invention, the alkali is one of sodium hydroxide, sodium carbonate, calcium hydroxide, sodium bicarbonate or a plurality of them in any proportion.

In step E of the present invention, the activated carbon is powder or granular.

In step F of the present invention, the solvent is one of dimethylsulfoxide (DMSO), dimethylformamide (DMF), acetone (CH ₃ COCH ₃ ), chloroform (chloroform), and silicone oil or multiples in any proportion.

In step F of the present invention, the acrylic acid (AA) monomer refers to acrylic acid (AA), acrylamide (AM), methacrylic acid (MAA), maleic anhydride (MAH), methacrylate ( One of MMA), ethylene glycol dimethacrylate (EGDMA) or any proportion of various monomer substances after removing the polymerization inhibitor.

In step F of the present invention, the specific shape is one or more of film shape, strip shape, fiber shape, ring shape, spherical shape and column shape.

In the step F of the present invention, the washing solvent for washing out the template amino acid is one of water, ethanol, acetone, methanol, etc. or a plurality of them in any proportion.

In step F of the present invention, the template amino acid is consistent with the finally obtained specific type of amino acid, which is any one of L-phenylalanine, L-tyrosine and L-histidine.

In step F of the present invention, the washing with ethanol or deionized water is specifically: according to the mass-to-volume ratio of material to liquid: 1:30-100 (the mass of the amino acid extraction polymer and the volume of deionized water or 10-60% ethanol solution Ratio, ie g/ml) immerse the amino acid extraction polymer in deionized water or 10-60% ethanol solution, sonicate at a temperature of 20-50°C for 15-60min, then let it stand for 1-6h, and filter to obtain washing liquid and raffinate And the polymer, the polymer is recycled after being freeze-dried.

In step F of the present invention, the ethanol is recovered and recycled by means of multi-stage vacuum distillation, the parameters of which are vacuum degree of 0.05-0.09Mpa and temperature of 50-85°C to obtain ethanol with a concentration of 90-98.5%.

In step G of the present invention, the ultrafiltration and nanofiltration are first ultrafiltration and then nanofiltration, and the membrane material used is one of polysulfone membrane, polytetrafluoroethylene membrane, PET, PAN or a variety of any ratio .

Beneficial technical effects brought by the present invention:

1. The present invention solves the problems in the process of using distiller's grains to prepare amino acids, and provides a method for preparing amino acids from distiller's grains. The protein and amino acid substances in distiller's grains are comprehensively utilized, and the protein in distiller's grains can be converted into amino acids. The amino acids with high value are obtained, the distiller's grains in the production of liquor are effectively treated, and the solid waste materials in the production process of the liquor enterprises are effectively utilized, so that the liquor enterprises can obtain certain economic benefits in the process of treating the distiller's grains waste. Benefits, with high marketing value. The method can save a large amount of extraction reagents, and while not introducing new substances, can also minimize process equipment and process costs, and has high product quality, which is suitable for industrial promotion.

2. The present invention is aimed at the characteristics of significant concentration and large amount of regional distribution of liquor production in my country, especially for the poor reproducibility and quantity of distiller's grains after producing liquor with one or several grains such as rice, sorghum, corn, wheat, and barley as main raw materials. Due to the characteristics of large size and low price, it is proposed to use alcohol to extract free amino groups and acid hydrolyze protein to prepare compound amino acids, and then use polymer molecular imprinting technology to extract specific types of amino acids in the compound amino acids. Using step-by-step extraction of amino acids, polymer recycling to extract specific types of amino acids, ultrafiltration and nanofiltration, the complete technical route of ethanol recovery and amino acid extraction is a systematic and effective development and comprehensive consideration of the main high-value components in liquor distillers grains. It achieves the purpose of reducing resource waste, preventing environmental pollution and making production technology feasible, and at the same time can solve technical problems in related industries, and realize the economic and social benefits of distiller's grains and other protease wastes in my country.

3. The present invention proposes a new technical route aiming at the treatment of solid waste liquor distiller's grains produced by liquor enterprises at present. The main by-product fresh distiller's grains with high moisture content in liquor production that is difficult to be directly utilized is dried by ordinary centrifugation or Drying, cleaning, drying and crushing, ultrasonic alcohol extraction, acid hydrolysis, neutralization and decolorization, polymer preparation and extraction of specific types of amino acids, impurity removal ultrafiltration nanofiltration, concentration separation, ethanol recovery and other steps to prepare specific types of amino acids and compound amino acids. Thereby the distiller's grains produced in the production of liquor are processed. The technology of the invention can selectively prepare compound amino acids and specific amino acids according to the current production situation. The technology is flexible and changeable, which can further improve the value of the product, and effectively solve the problem of bad governance of liquor distiller's grains that are easy to spoil and deteriorate and easily pollute the environment. problems, reducing the pressure on environmental protection.

4. Step A of the present invention preferably adopts a specific liquor distiller's grains pretreatment method and a specific combination of process parameters. On the one hand, the method can minimize impurities in liquor distillers grains, reduce useless consumption of subsequent alcohol extraction/acidolysis, and improve production efficiency while reducing losses. On the other hand, it can maintain the quality of liquor distiller's grain raw materials, reduce the fluctuation of production process parameters, and improve the stability of compound amino acid products and specific amino acid products.

5. Step D of the present invention preferably adopts a specific neutralization treatment method and a specific combination of process parameters. Controlling the specific temperature and pH value, adding a specific concentration of lime milk solution can better remove SO ₄ ^2- ions, suspended impurities and H ⁺ in the solution, and play the role of removing impurities and adjusting the pH of the solution. On the one hand, the specific stirring speed and time can make the calcium sulfate precipitates not easy to scale on the container wall, which will affect the heat conduction effect and the problem of pipeline blockage; on the other hand, the impurities in the solution can be adsorbed by the precipitated calcium sulfate and precipitate together , to improve the purity of the solution; the specific standing time can further separate the precipitate and the solution.

6. Step E of the present invention preferably uses a specific activated carbon decolorization method and a specific combination of process parameters. This specific method and parameter combination can better improve the adsorption efficiency of activated carbon.

7. In the step F of the present invention, it is preferable to use a combination of specific polymer monomers and specific process parameters. Controlling specific polymerized monomers that remove inhibitors, on the one hand, is beneficial to improve the efficiency, precision and polymer performance of the polymerization between monomers, and on the other hand, it is beneficial to the -COOH, -NH ₂ and amino acids on the polymer molecular chain The hydrogen bonding between -COOH and -NH ₂ on the molecule improves the interaction between the polymer and the amino acid molecule, which is conducive to improving the efficiency of the polymer's adsorption and release of amino acids; the specific shape is not only conducive to improving the stability of the polymer, In addition to increasing the number of times the polymer is recycled, it is also beneficial to increase the contact area between the polymer and the amino acid solution, and improve the efficiency of adsorption and release of amino acids; in addition, the recycling of the extracted polymer can ensure that no new substances are introduced into the filtrate and raffinate , It can process distiller's grains produced in different batches in the production of liquor enterprises, is less affected by the liquor production process, and can also minimize the consumption of chemicals and process costs. The time for ultrasonication, heating for dissolution and standing can ensure that the amino acid and the polymer are fully dissolved and contacted quickly; the stirring rate of 30-80r/min avoids the waste of energy caused by excessive local heat and speed.

8. Step G of the present invention preferably adopts a specific ultrafiltration and nanofiltration method and a specific combination of process parameters. The method adopts cross-flow filtration with specific process parameters, on the one hand, it can maintain the stability of the filtrate temperature, and on the other hand, it can improve the utilization rate of heat energy. Ultrafiltration can remove enzyme proteins with large molecular weight, colloids and some calcium sulfate precipitates in the filtrate, nanofiltration can further remove small molecular weight pigments and other salts in the solution, and greatly increase the concentration of amino acids in the solution. purity.

9. Step H of the present invention preferably adopts a specific concentration and drying method and a specific combination of process parameters. The concentration of specific process parameters in the method can reduce energy consumption and improve the recovery efficiency of amino acids; the vacuum drying of specific process parameters can reduce energy consumption, save drying time and improve production efficiency.

detailed description

Example 1

A method for preparing amino acids from liquor distillers grains, comprising the following process steps:

A. Pretreatment of liquor distiller's grains

Pretreating distiller's grains of liquor to obtain pretreated distiller's grains of liquor;

B. Alcoholic extraction of liquor distiller's grains

Ultrasonication is performed on the pretreated distiller's grains in step A in 45% alcohol solution, and the filtrate and filter residue are obtained by filtration;

C. Acid hydrolysis of liquor lees

After centrifugal drying, the filter residue obtained in step B was hydrolyzed and filtered under the conditions of an acid concentration of 2 mol/L, a solid-to-liquid mass-volume ratio of 1:8, a temperature of 80°C, and a time of 1 h to obtain a filtrate;

D. Filtrate neutralization

Mix the filtrates obtained in step B and step C, add alkaline solution after the mixed filtrate is cooled to 30°C for neutralization, adjust the pH value of the solution to 3.0, precipitate and centrifuge to obtain filtrate and precipitate, and wash the precipitate with an appropriate amount of water to obtain filtrate , and then the two filtrates are mixed to obtain a neutralized filtrate;

E. Activated carbon decolorization

Adjusting the pH value of the neutralization filtrate obtained in step D, so that the pH value of the neutralization filtrate is 3.0, and then performing activated carbon decolorization treatment to obtain a decolorization solution;

F. Extraction of amino acids

Acrylonitrile monomers and acrylic monomers are used to polymerize to obtain PAN-based polymers, and then the template amino acid and PAN-based polymers are heated and dissolved in a solvent at a mass ratio of 1:25 to obtain a polymer solution; acrylonitrile monomers can also be Polymerization of monomers, acrylic monomers, and template amino acids, and then heating and dissolving the polymers in solvents to obtain polymer solutions; then ultrasonication was carried out at a stirring rate of 30r/min, and stirring was continued for 15 minutes to make it into a specific shape. Freeze-drying at low temperature, washing out the template amino acid, and obtaining the amino acid extraction polymer through low-temperature freeze-drying, which is set aside;

Soak the amino acid extraction polymer in the decolorization solution obtained in step E, take it out after 1 hour, wash the amino acid in the amino acid extraction polymer with ethanol or deionized water, and collect the washing solution and residual liquid;

G. Ultrafiltration and nanofiltration

Both the washing solution and the raffinate obtained in step F are purified by ultrafiltration and nanofiltration to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate;

H. Concentrated and dried

The ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively subjected to low-temperature vacuum concentration treatment, then dried, pulverized, and packaged to obtain specific types of amino acid products and compound amino acid products respectively.

Example 2

A method for preparing amino acids from liquor distillers grains, comprising the following process steps:

A. Pretreatment of liquor distiller's grains

Pretreating distiller's grains of liquor to obtain pretreated distiller's grains of liquor;

B. Alcoholic extraction of liquor distiller's grains

Ultrasonication is performed on the pretreated distiller's grains in step A in 85% alcohol solution, and the filtrate and filter residue are obtained by filtration;

C. Acid hydrolysis of liquor lees

After centrifugal drying, the filter residue obtained in step B was hydrolyzed and filtered under the conditions of an acid concentration of 6 mol/L, a solid-to-liquid mass-to-volume ratio of 1:50, a temperature of 140°C, and a time of 12 hours to obtain a filtrate;

D. Filtrate neutralization

Mix the filtrates obtained in step B and step C, add alkaline solution after the mixed filtrate is cooled to 30°C for neutralization, adjust the pH value of the solution to 6.0, centrifuge the precipitate to obtain filtrate and precipitate, and wash the precipitate with an appropriate amount of water to obtain filtrate , and then the two filtrates are mixed to obtain a neutralized filtrate;

E. Activated carbon decolorization

Adjusting the pH value of the neutralization filtrate obtained in step D, so that the pH value of the neutralization filtrate is 7.0, and then performing activated carbon decolorization treatment to obtain a decolorization solution;

F. Extraction of amino acids

Acrylonitrile monomers and acrylic monomers are used to polymerize to obtain PAN-based polymers, and then the template amino acid and PAN-based polymers are heated and dissolved in a solvent at a mass ratio of 1:50 to obtain a polymer solution; acrylonitrile monomers can also be Polymers, acrylic monomers, and template amino acids are directly polymerized, and then the polymer is heated and dissolved in a solvent to obtain a polymer solution; then ultrasound is performed at a stirring rate of 80r/min, and it is made into a specific shape after stirring for 60 minutes. Freeze-drying at low temperature, washing out the template amino acid, and obtaining the amino acid extraction polymer through low-temperature freeze-drying, which is set aside;

Soak the amino acid extraction polymer in the decolorization solution obtained in step E, take it out after 6 hours, wash the amino acid in the amino acid extraction polymer with ethanol or deionized water, and collect the washing solution and residual liquid;

G. Ultrafiltration and nanofiltration

Both the washing solution and the raffinate obtained in step F are purified by ultrafiltration and nanofiltration to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate;

H. Concentrated and dried

The ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively subjected to low-temperature vacuum concentration treatment, then dried, pulverized, and packaged to obtain specific types of amino acid products and compound amino acid products respectively.

Example 3

A method for preparing amino acids from liquor distillers grains, comprising the following process steps:

A. Pretreatment of liquor distiller's grains

Pretreating distiller's grains of liquor to obtain pretreated distiller's grains of liquor;

B. Alcoholic extraction of liquor distiller's grains

Ultrasonic ultrasonication is carried out in 65% alcohol solution with the distiller's grains of pretreatment in step A, and filtrate and filter residue are obtained by filtering;

C. Acid hydrolysis of liquor lees

After centrifugal drying, the filter residue obtained in step B was hydrolyzed and filtered under the conditions of an acid concentration of 4 mol/L, a solid-to-liquid mass-volume ratio of 1:29, a temperature of 110°C, and a time of 6.5 hours to obtain a filtrate;

D. Filtrate neutralization

Mix the filtrates obtained in step B and step C, add alkaline solution after the mixed filtrate is cooled to 30°C for neutralization, adjust the pH value of the solution to 4.5, centrifuge the precipitate to obtain filtrate and precipitate, and wash the precipitate with an appropriate amount of water to obtain filtrate , and then the two filtrates are mixed to obtain a neutralized filtrate;

E. Activated carbon decolorization

Adjusting the pH value of the neutralization filtrate obtained in step D, so that the pH value of the neutralization filtrate is 5.0, and then performing activated carbon decolorization treatment to obtain a decolorization solution;

F. Extraction of amino acids

Acrylonitrile monomers and acrylic monomers are used to polymerize to obtain PAN-based polymers, and then the template amino acid and PAN-based polymers are heated and dissolved in a solvent at a mass ratio of 1:37.5 to obtain a polymer solution; acrylonitrile monomers can also be Polymers, acrylic monomers and template amino acids are directly polymerized, and then the polymer is heated and dissolved in a solvent to obtain a polymer solution; then ultrasonic is performed at a stirring rate of 55r/min, and it is made into a specific shape after stirring for 37.5min. After low-temperature freeze-drying, the template amino acid is washed away, and the amino acid extraction polymer is obtained through low-temperature freeze-drying, which is set aside;

Soak the amino acid extraction polymer in the decolorization solution obtained in step E, take it out after 3.5 hours, wash the amino acid in the amino acid extraction polymer with ethanol or deionized water, and collect the washing solution and residual liquid;

G. Ultrafiltration and nanofiltration

Both the washing solution and the raffinate obtained in step F are purified by ultrafiltration and nanofiltration to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate;

H. Concentrated and dried

The ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively subjected to low-temperature vacuum concentration treatment, then dried, pulverized, and packaged to obtain specific types of amino acid products and compound amino acid products respectively.

Example 4

A method for preparing amino acids from liquor distillers grains, comprising the following process steps:

A. Pretreatment of liquor distiller's grains

Pretreating distiller's grains of liquor to obtain pretreated distiller's grains of liquor;

B. Alcoholic extraction of liquor distiller's grains

Ultrasonic ultrasonication is carried out in the 75% alcohol solution of the distiller's grains of the pretreatment in step A, and filtration obtains filtrate and filter residue;

C. Acid hydrolysis of liquor lees

After centrifugal drying, the filter residue obtained in step B was hydrolyzed and filtered under the conditions of an acid concentration of 3 mol/L, a solid-to-liquid mass-volume ratio of 1:36, a temperature of 90°C, and a time of 10 h to obtain a filtrate;

D. Filtrate neutralization

Mix the filtrates obtained in step B and step C, add alkaline solution after the mixed filtrate is cooled to 30°C for neutralization, adjust the pH value of the solution to 4.0, centrifuge the precipitate to obtain filtrate and precipitate, and wash the precipitate with an appropriate amount of water to obtain filtrate , and then the two filtrates are mixed to obtain a neutralized filtrate;

E. Activated carbon decolorization

Adjusting the pH value of the neutralization filtrate obtained in step D, so that the pH value of the neutralization filtrate is 6.0, and then performing activated carbon decolorization treatment to obtain a decolorization solution;

F. Extraction of amino acids

Acrylonitrile monomers and acrylic monomers are used to polymerize to obtain PAN-based polymers, and then the template amino acid and PAN-based polymers are heated and dissolved in a solvent at a mass ratio of 1:48 to obtain a polymer solution; acrylonitrile monomers can also be directly polymerize the monomer, acrylic monomer and template amino acid, and then heat and dissolve the polymer in the solvent to obtain a polymer solution; then perform ultrasonication at a stirring rate of 35r/min, continue stirring for 30min, and make it into a specific shape. Freeze-drying at low temperature, washing out the template amino acid, and obtaining the amino acid extraction polymer through low-temperature freeze-drying, which is set aside;

Soak the amino acid extraction polymer in the decolorization solution obtained in step E, take it out after 2 hours, wash the amino acid in the amino acid extraction polymer with ethanol or deionized water, and collect the washing solution and residual liquid;

G. Ultrafiltration and nanofiltration

Both the washing solution and the raffinate obtained in step F are purified by ultrafiltration and nanofiltration to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate;

H. Concentrated and dried

The ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively subjected to low-temperature vacuum concentration treatment, then dried, pulverized, and packaged to obtain specific types of amino acid products and compound amino acid products respectively.

Example 5

On the basis of embodiment 1-4:

Preferably, in step A, the pretreatment of the liquor distiller's grains specifically includes: centrifuging the fresh liquor distiller's grains at room temperature for 15 minutes under the condition of 200 r/min, drying or drying them, sieving to remove impurities, and then dissolving the distiller's distillers' grains in the Ultrasonic cleaning at room temperature for 15 minutes, the mass-to-volume ratio of material to liquid is 1:5, and then centrifuged at room temperature at 200 r/min for 15 minutes, then filtered, and the filter residue was dried or air-dried to a moisture content of 3%, and then the After the distiller's grains are pulverized, they are sieved to a fineness of 20 mesh for later use.

Preferably, in step B, the alcohol extraction of the liquor distiller's grains is specifically: the liquor distiller's grains that have been pretreated in step A are heated with Ultrasound with a power of 120W was used for 15 minutes, and then the filtrate and filter residue were obtained by filtration.

Preferably, in step D, the neutralization of the filtrate is specifically: mixing the filtrate obtained in step B and step C, detecting the pH value of the mixed filtrate, and then using 11°Bé under the condition that the stirring speed is 50r/min The milk of lime solution is added while stirring to adjust the pH value to 3.0, and it is filtered after standing for 30min to obtain filtrate and precipitate, and the precipitate is washed with deionized water with a material-to-liquid volume ratio of 1:6 to obtain the filtrate. The two filtrates are then combined to obtain a neutralized filtrate.

Preferably, in step E, the decolorization of activated carbon specifically includes: adding 3% activated carbon to the neutralized filtrate obtained in step D, adjusting the pH value of the neutralized filtrate to 3.0, and the temperature at 50°C under the condition of 100r/min Stir and decolorize for 30 minutes to obtain a decolorized solution.

Preferably, in step F, the low-temperature freeze-drying parameters described twice are vacuum degree of 0.1 Pa, temperature of minus 85° C., and time of 4 hours.

Preferably, in step G, the ultrafiltration and nanofiltration treatment specifically includes: using an ultrafiltration membrane with a molecular weight cutoff of 1500 and a nanofiltration membrane with a molecular weight cutoff of 100, at an operating pressure of 0.6 MPa, filter Perform cross-flow ultrafiltration and nanofiltration on the washing solution and raffinate obtained in step F at a temperature of 30° C. to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate.

Preferably, in step H, the concentrated drying is specifically: the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively carried out under the conditions of a vacuum degree of 0.08Mpa and a temperature of 60°C Vacuum concentration treatment for 30 minutes, so that the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid are respectively concentrated to 1/6 of their original volumes, respectively, to obtain specific types of amino acid concentrates and compound amino acid concentrates; then vacuum at 60 ° C Dried to a moisture content of 3%, crushed and packaged to obtain specific types of amino acid products and compound amino acid products.

Example 6

On the basis of embodiment 1-4:

Preferably, in step A, the pretreatment of the liquor distiller's grains specifically includes: centrifuging the fresh liquor distiller's grains at room temperature for 30 minutes under the condition of 3000r/min, drying or drying them, sieving to remove impurities, and then dissolving the distiller's distillers' grains in the Ultrasonic cleaning at room temperature for 60 minutes, the mass-volume ratio of material to liquid is 1:20, and then centrifuged at room temperature at 3000r/min for 30 minutes and then filtered, the filter residue is dried or air-dried to a moisture content of 8%, and then the dried or dried liquor After the distiller's grains are pulverized, they are sieved to a fineness of 80 mesh for later use.

Preferably, in step B, the alcohol extraction of the liquor distiller's grains is specifically: the liquor distiller's grains that have been pretreated in step A are heated with Ultrasound with a power of 200W was used for 60 minutes, and then the filtrate and filter residue were obtained by filtration.

Preferably, in step D, the neutralization of the filtrate is specifically: mixing the filtrate obtained in step B and step C, detecting the pH value of the mixed filtrate, and then using 15°Bé under the condition that the stirring speed is 80r/min The milk of lime solution was added while stirring to adjust the pH value to 6.0, and it was filtered after standing for 90min to obtain filtrate and precipitate, and the precipitate was washed with deionized water with a material-to-liquid volume ratio of 1:10 to obtain the filtrate. The two filtrates are then combined to obtain a neutralized filtrate.

Preferably, in step E, the activated carbon decolorization is specifically: adding 10% activated carbon to the neutralized filtrate obtained in step D, adjusting the neutralized filtrate to pH 7.0, temperature 80°C, under the condition of 300r/min Stir and decolorize for 120 minutes to obtain a decolorized solution.

Preferably, in step F, the low-temperature freeze-drying parameters described twice are a vacuum degree of 10 Pa, a temperature of minus 55° C., and a time of 24 hours.

Preferably, in step G, the ultrafiltration and nanofiltration treatment specifically includes: using an ultrafiltration membrane with a molecular weight cutoff of 20,000 and a nanofiltration membrane with a molecular weight cutoff of 800, at an operating pressure of 2.0 MPa, filter Under the condition of 70° C., cross-flow ultrafiltration and nanofiltration are performed on the washing liquid and raffinate obtained in step F to obtain ultrafiltration nanofiltration washing liquid and ultrafiltration nanofiltration raffinate.

Preferably, in step H, the concentrated drying is specifically: the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively carried out under the conditions of a vacuum degree of 0.1Mpa and a temperature of 90°C Vacuum concentration treatment for 60 minutes, so that the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid are respectively concentrated to 1/2 of their original volumes, respectively, to obtain specific types of amino acid concentrates and compound amino acid concentrates; then vacuum at 90 ° C Dried to a moisture content of 8%, crushed and packaged to obtain specific types of amino acid products and compound amino acid products.

Example 7

On the basis of embodiment 1-4:

Preferably, in step A, the pretreatment of the liquor distiller's grains specifically includes: centrifuging the fresh liquor distiller's grains at room temperature for 22.5 minutes under the condition of 1600r/min, drying or drying, sieving to remove impurities, and then dissolving the liquor distiller's grains Ultrasonic cleaning at room temperature for 37.5 minutes, the mass-to-volume ratio of material to liquid is 1:12.5, and then centrifuged at room temperature for 22.5 minutes at 1600r/min and then filtered. The filter residue is dried or air-dried to a moisture content of 5.5%, and then dried or air-dried After the dried distiller's grains are pulverized, they are sieved to a fineness of 50 mesh for later use.

Preferably, in step B, the alcohol extraction of the liquor distiller's grains is specifically: the liquor distiller's grains that have been pretreated in step A are heated with Ultrasound with a power of 160W was used for 37.5 minutes, and then filtered to obtain filtrate and filter residue.

Preferably, in step D, the neutralization of the filtrate is specifically: mixing the filtrate obtained in step B and step C, detecting the pH value of the mixed filtrate, and then using 13°Bé under the condition that the stirring speed is 65r/min The milk of lime solution is added while stirring to adjust the pH value to 4.5, and it is filtered after standing for 60min to obtain filtrate and precipitate, and the precipitate is washed with deionized water with a material-to-liquid volume ratio of 1:8 to obtain the filtrate. The two filtrates are then combined to obtain a neutralized filtrate.

Preferably, in step E, the activated carbon decolorization is specifically: adding 6.5% activated carbon to the neutralized filtrate obtained in step D, adjusting the neutralized filtrate to pH 5.0, temperature 65°C, under the condition of 200r/min Stir and decolorize for 75 minutes to obtain a decolorized solution.

Preferably, in step F, the low-temperature freeze-drying parameters described twice are a vacuum degree of 5 Pa, a temperature of minus 70° C., and a time of 14 hours.

Preferably, in step G, the ultrafiltration and nanofiltration treatment specifically includes: using an ultrafiltration membrane with a molecular weight cut-off of 10750 and a nanofiltration membrane with a molecular weight cut-off of 450, at an operating pressure of 1.3 MPa, filter Perform cross-flow ultrafiltration and nanofiltration on the washing liquid and raffinate obtained in step F at a temperature of 50° C. to obtain ultrafiltration nanofiltration washing liquid and ultrafiltration nanofiltration raffinate.

Preferably, in step H, the concentrated drying is specifically: the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively carried out under the conditions of a vacuum degree of 0.09Mpa and a temperature of 75°C Vacuum concentration treatment for 45 minutes, so that the ultrafiltration and nanofiltration washing liquid and ultrafiltration and nanofiltration residual liquid are respectively concentrated to 1/4 of their original volumes, respectively, to obtain specific types of amino acid concentrates and compound amino acid concentrates; then vacuum at 75 ° C Dried to a moisture content of 5.5%, crushed and packaged to obtain specific types of amino acid products and compound amino acid products.

Example 8

On the basis of embodiment 1-4:

Preferably, in step A, the pretreatment of the liquor distiller's grains specifically includes: centrifuging the fresh liquor distiller's grains at room temperature for 20 minutes under the condition of 1000 r/min, drying or drying them, sieving to remove impurities, and then dissolving the distiller's distillers' grains in the Ultrasonic cleaning at room temperature for 30 minutes, the mass-to-volume ratio of material to liquid is 1:18, and then centrifuged at room temperature for 21 minutes at 800 r/min, then filtered, and the filter residue is dried or air-dried to a moisture content of 6%, and then the dried or dried liquor The distiller's grains are pulverized and sieved to a fineness of 70 mesh for later use.

Preferably, in step B, the alcohol extraction of the liquor distiller's grains is specifically: the liquor distiller's grains that have been pretreated in step A are heated with Ultrasound with a power of 180W for 52 minutes, and then filtered to obtain filtrate and filter residue.

Preferably, in step D, the neutralization of the filtrate is specifically: mixing the filtrates obtained in step B and step C, detecting the pH value of the mixed filtrate, and then using 12°Bé under the condition that the stirring speed is 70r/min The milk of lime solution is added while stirring to adjust the pH value to 5, and it is filtered after standing for 80min to obtain filtrate and precipitate, and the precipitate is washed with deionized water with a material-to-liquid volume ratio of 1:7 to obtain the filtrate. The two filtrates are then combined to obtain a neutralized filtrate.

Preferably, in step E, the decolorization of activated carbon is specifically: adding 5% activated carbon to the neutralized filtrate obtained in step D, adjusting the pH value of the neutralized filtrate to 6.0, and the temperature at 52°C under the condition of 150r/min Stir and decolorize for 60 minutes to obtain a decolorized solution.

Preferably, in step F, the low-temperature freeze-drying parameters described twice are a vacuum degree of 2.5 Pa, a temperature of minus 65° C., and a time of 20 h.

Preferably, in step G, the ultrafiltration and nanofiltration treatment specifically includes: using an ultrafiltration membrane with a molecular weight cut-off of 10,000 and a nanofiltration membrane with a molecular weight cut-off of 700, at an operating pressure of 1.2 MPa, filter Under the condition of 45° C., cross-flow ultrafiltration and nanofiltration are performed on the washing liquid and raffinate obtained in step F to obtain ultrafiltration nanofiltration washing liquid and ultrafiltration nanofiltration raffinate.

Preferably, in step H, the concentrated drying is specifically: the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively carried out under the conditions of a vacuum degree of 0.085Mpa and a temperature of 65°C. Vacuum concentration treatment for 47 minutes, so that the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid are respectively concentrated to 1/5 of their original volumes, respectively, to obtain specific types of amino acid concentrates and compound amino acid concentrates; then vacuum at 88 ° C Dried to a moisture content of 7.2%, crushed and packaged to obtain specific types of amino acid products and compound amino acid products.

Example 9

On the basis of embodiment 1-8:

Preferably, in step F, the washing with ethanol or deionized water specifically includes: immersing the amino acid extraction polymer in deionized water or 10% ethanol solution at a temperature of 20° C. After ultrasonication for 15 minutes, let it stand for 1 hour, and filter the washing solution, residual solution and polymer, and the polymer can be recycled after freeze-drying.

Preferably, in step F, the ethanol is recovered and recycled by means of multi-stage vacuum distillation with parameters of vacuum degree of 0.05Mpa and temperature of 50°C to obtain ethanol with a concentration of 90%.

Example 10

On the basis of embodiment 1-8:

Preferably, in step F, the washing with ethanol or deionized water specifically includes: immersing the amino acid extraction polymer in deionized water or 60% ethanol solution at a temperature of 50° C. After ultrasonication for 60 minutes, it was left to stand for 6 hours, and the washing solution, raffinate and polymer were obtained by filtration, and the polymer was recycled after freeze-drying.

Preferably, in step F, the ethanol is recovered and recycled by means of multi-stage vacuum distillation with parameters of vacuum degree of 0.09Mpa and temperature of 85°C to obtain ethanol with a concentration of 98.5%.

Example 11

On the basis of embodiment 1-8:

Preferably, in step F, the washing with ethanol or deionized water specifically includes: immersing the amino acid extraction polymer in deionized water or 35% ethanol solution at a temperature of 35° C. After ultrasonication for 37.5min, stand still for 3.5h, filter the washing solution, raffinate and polymer, and the polymer can be recycled after being freeze-dried.

Preferably, in step F, the ethanol is recovered and recycled by means of multi-stage vacuum distillation with parameters of vacuum degree of 0.07Mpa and temperature of 67.5°C to obtain ethanol with a concentration of 95%.

Example 12

On the basis of embodiment 1-8:

Preferably, in step F, the washing with ethanol or deionized water specifically includes: immersing the amino acid extraction polymer in deionized water or 20% ethanol solution at a temperature of 40° C. After ultrasonication for 30 minutes, let it stand for 2 hours, filter the washing liquid, residual liquid and polymer, and the polymer can be recycled after being freeze-dried.

Preferably, in step F, the ethanol is recovered and recycled by means of multi-stage vacuum distillation with parameters of vacuum degree of 0.06Mpa and temperature of 80°C to obtain ethanol with a concentration of 96%.

Claims (10)

1. A method utilizing distiller's grains to prepare amino acids, characterized in that: comprising the following processing steps: A. Pretreatment of liquor distiller's grains Pretreating distiller's grains of liquor to obtain pretreated distiller's grains of liquor; B. Alcoholic extraction of liquor distiller's grains ultrasonically ultrasonicating the pretreated distiller's grains in step A in 45-85% alcohol solution, and filtering to obtain filtrate and filter residue; C. Acid hydrolysis of liquor lees After centrifugal drying, the filter residue obtained in step B is hydrolyzed and filtered under the conditions of an acid concentration of 2-6mol/L, a solid-liquid mass-volume ratio of 1:8-50, a temperature of 80-140°C, and a time of 1-12h to obtain a filtrate; D. Filtrate neutralization Mix the filtrate obtained in step B and step C, and add an alkaline solution to neutralize the mixed filtrate after it is cooled to 30°C, adjust the pH value of the solution to 3.0-6.0, precipitate and centrifuge to obtain filtrate and precipitate, and wash the precipitate with an appropriate amount of water Obtain the filtrate, then these two filtrates are mixed to obtain the neutralized filtrate; E. Activated carbon decolorization Adjusting the pH value of the neutralized filtrate obtained in step D, so that the pH value of the neutralized filtrate is 3.0-7.0, and then performing activated carbon decolorization treatment to obtain a decolorized solution; F. Extraction of amino acids Use acrylonitrile monomers and acrylic monomers to polymerize to obtain PAN-based polymers, and then heat and dissolve the template amino acid and PAN-based polymers in a solvent at a mass ratio of 1:25-50 to obtain a polymer solution; Nitrile monomers, acrylic monomers, and template amino acids are directly polymerized, and then the polymers are heated and dissolved in a solvent to obtain a polymer solution; then ultrasound is performed at a stirring rate of 30-80r/min, and the stirring is continued for 15-60min. Made into a specific shape, freeze-dried at low temperature, washed out the template amino acid, and obtained amino acid extraction polymer through low-temperature freeze-drying, and set aside; Soak the amino acid extraction polymer in the decolorization solution obtained in step E, take it out after 1-6 hours, wash the amino acid in the amino acid extraction polymer with ethanol or deionized water, and collect the washing solution and residual liquid; G. Ultrafiltration and nanofiltration Both the washing solution and the raffinate obtained in step F are purified by ultrafiltration and nanofiltration to obtain ultrafiltration nanofiltration washing solution and ultrafiltration nanofiltration raffinate; H. Concentrated and dried The ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration residual liquid obtained in step G are respectively subjected to low-temperature vacuum concentration treatment, then dried, pulverized, and packaged to obtain specific types of amino acid products and compound amino acid products respectively. 2. A method for preparing amino acids by using distiller's grains according to claim 1, characterized in that: in step A, the pretreatment of said distiller's grains is specifically: putting fresh distiller's grains at 200-3000r/min Centrifuge at room temperature for 15-30min under certain conditions, dry or dry, sieve to remove impurities, and then ultrasonically clean the distiller's grains at room temperature for 15-60min, the mass-volume ratio of material to liquid is 1:5-20, and then 200-3000r/min Centrifuge at room temperature for 15-30 minutes under certain conditions, filter, and dry or air-dry the filter residue to a moisture content of 3-8%, then crush the dried or air-dried distiller's grains, and sieve to a fineness of 20-80 mesh for later use. 3. A method for preparing amino acids using distiller's grains according to claim 1, characterized in that: in step B, the alcohol extraction of said distiller's grains is specifically: the pretreated distiller's grains in step A Under the conditions of temperature 25-85°C, alcohol solution concentration 45-85%, stirring speed 100-300r/min, ultrasonic wave with power 120-200W for 15-60min, and then filter to obtain filtrate and filter residue. 4. A method for preparing amino acids from distiller's grains according to claim 1, characterized in that: in step D, the neutralization of the filtrate is specifically: mixing the filtrates obtained in step B and step C, and detecting the mixed The pH value of the filtrate, then adjust the pH value to 3.0-6.0 with the milk of lime solution of 11-15 ° Bé under the condition of stirring speed of 50-80r/min while adding and stirring, and after standing for 30-90min Filtration is performed to obtain a filtrate and a precipitate, and the precipitate is washed with deionized water with a volume ratio of 1:6-10 to obtain a filtrate, and then the two filtrates are mixed to obtain a neutralized filtrate. 5. A method for preparing amino acids from distiller's grains according to claim 1, characterized in that: in step E, the decolorization of the activated carbon is specifically: adding 3-10% to the neutralized filtrate obtained in step D activated carbon, adjust the pH value of the neutralization filtrate to 3.0-7.0, and the temperature to 50-80° C., and stir and decolorize it for 30-120 minutes under the condition of 100-300 r/min to obtain a decolorized solution. 6. A method for preparing amino acids from distiller's grains according to claim 1, characterized in that: in step F, the low-temperature freeze-drying parameters described twice are vacuum degree 0.1-10Pa, temperature minus 85-minus 55 ℃, the time is 4-24h. 7. A method for preparing amino acids from distiller's grains according to claim 1, characterized in that: in step G, the ultrafiltration and nanofiltration treatment is specifically: using an ultrafiltration filter with a molecular weight cut-off of 1500-20000 The filter membrane and the nanofiltration membrane with a relative molecular mass cut-off of 100-800, under the conditions of an operating pressure of 0.6-2.0MPa and a filtration temperature of 30-70°C, perform cross-flow ultrafiltration on the washing liquid and raffinate obtained in step F. Filtration and nanofiltration to obtain ultrafiltration and nanofiltration washing liquid and ultrafiltration and nanofiltration raffinate. 8. A method for preparing amino acids by using distiller's grains according to claim 1, characterized in that: in step H, the concentrated drying is specifically: the ultrafiltration and nanofiltration washing liquid obtained in step G and the ultrafiltration The nanofiltration raffinate was vacuum concentrated for 30-60 minutes under the conditions of vacuum degree of 0.08-0.1Mpa and temperature of 60-90°C, so that the ultrafiltration and nanofiltration washing liquid and the ultrafiltration and nanofiltration raffinate were concentrated to their respective 1/2-1/6 of the original volume to obtain specific types of amino acid concentrates and compound amino acid concentrates; then vacuum-dry at 60-90°C until the moisture content is 3-8%, crush and pack to obtain specific types Amino acid products and compound amino acid products. 9. A method for preparing amino acids by using distiller's grains according to claim 1 or 6, characterized in that: in step F, the washing with ethanol or deionized water is specifically: according to the mass-volume ratio of material to liquid: 1 : 30-100 immerse the amino acid extraction polymer in deionized water or 10-60% ethanol solution, ultrasonic at a temperature of 20-50°C for 15-60min, then stand for 1-6h, and filter to obtain washing liquid, raffinate and polymer , the polymer is recycled after being freeze-dried. 10. A method for preparing amino acids from distiller's grains according to claim 1 or 6, characterized in that: in step F, the ethanol is recovered and recycled by multi-stage vacuum distillation, and its parameter is vacuum degree 0.05-0.09Mpa, temperature 50-85°C, to obtain ethanol with a concentration of 90-98.5%.