A pretreatment method for recovering betaine from molasses fermentation mash

Abstract

The present invention relates to the technical field of betaine extraction methods, and in particular to a pretreatment method for recovering betaine from molasses fermentation mash. The method comprises the following steps: (1) adding alkali metal oxide or alkali metal hydroxide and alkali metal carbonate to molasses fermentation mash for precipitation reaction, wherein the molar ratio of the alkali metal carbonate to the calcium ion in the molasses fermentation mash is 0.8-2.2:1, and the pH of the precipitation reaction is ≥10.5; (2) separating and removing solid impurities from the reaction mixture of step (1) to obtain a filtrate. The pretreatment method of the present invention uses alkali metal oxide or alkali metal hydroxide and alkali metal inorganic acid salt as precipitants, and the removal rate of calcium and magnesium ions reaches more than 82%; the mother liquor obtained by the pretreatment method of the present invention is subjected to chromatography, and the pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 4 weeks.

Description

Technical Field

[0001] The invention relates to the technical field of betaine extraction methods, and in particular to a pretreatment method for recovering betaine from molasses fermentation mash. Background Art

[0002] Molasses is a byproduct obtained after sugar extraction from sugar materials such as sugar cane, beets, glucose or corn. It mainly contains a large amount of fermentable sugar (mainly sucrose) and is a good fermentation raw material. It is usually used in the fermentation industry to produce baker's yeast, alcohol, monosodium glutamate, citric acid, lysine and antibiotics. The mash left after fermentation is collectively referred to as molasses fermentation mash, and the concentrate obtained by evaporation is usually called fermentation concentrate. Molasses fermentation concentrate is rich in a large number of nutrients and a variety of inorganic elements, and can be used to produce fertilizers and feed. The market demand for these two products is limited, and there is already an oversupply. Therefore, people are paying more and more attention to the recovery of high value-added components in fermentation concentrates, such as betaine, amino acids, glycerol and inositol. Recycling these valuable compounds can realize the resource utilization of fermentation concentrates.

[0003] In the process of recovering betaine from molasses fermentation concentrate, the chromatography system is usually the preferred purification step. The key step of this operation is to remove suspended matter in the feed of the chromatography system equipment, such as biological cells and other inert minerals such as calcium and magnesium. This process is called clarification or pretreatment. Common physical clarification methods include natural sedimentation, centrifugation, diatomaceous earth filtration or microfiltration, etc. However, the existing methods have limited clarification effects on calcium and magnesium ions in molasses fermentation concentrate. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a pretreatment method for recovering betaine from molasses fermentation mash, and reduce the content of calcium and magnesium ions in the chromatography feed. When the calcium and magnesium ions in the solution are too high, the organic matter in the solution will react with the calcium and magnesium ions to form a complex, thereby affecting the formation of chromatographic peaks in the chromatography system. In addition, under alkaline conditions, calcium and magnesium ions will form precipitates with anions such as hydroxide, carbonate, and sulfate in the solution, which will affect the scaling and blockage of the resin in the downstream chromatography system. These potential factors will shorten the cleaning cycle and service life of the resin, and reduce the production efficiency of the chromatography system. The reduction in efficiency usually means a reduction in product purity, production capacity, and increased energy consumption of the process. Therefore, it is necessary to reduce the content of calcium and magnesium ions in the chromatography feed during the clarification process.

[0005] In view of the shortcomings of the prior art, one of the objects of the present invention is to provide a pretreatment method for recovering betaine from molasses fermentation mash, and the second object of the present invention is to provide a method for recovering betaine from molasses fermentation mash.

[0006] The technical solution of the present invention:

[0007] The present invention provides a pretreatment method for recovering betaine from molasses fermentation concentrate, comprising the following steps:

[0008] (1) adding an alkali metal oxide or an alkali metal hydroxide and an alkali metal carbonate to the molasses fermentation mash to carry out a precipitation reaction, wherein the molar ratio of the alkali metal carbonate to the calcium ion in the molasses fermentation mash is 0.8-2.2:1, and the pH of the precipitation reaction is ≥10.5;

[0009] (2) Separating the reaction mixture of step (1) to remove solid impurities and obtain a filtrate.

[0010] Preferably, the molasses fermentation mash is a mash obtained by biological fermentation and separation of betaine-containing crops or hydrolyzates of betaine-containing crops.

[0011] Preferably, the betaine-containing crops include but are not limited to sugar beet, wolfberry, soybean, corn and wheat.

[0012] Preferably, the molar ratio of the alkali metal carbonate to the calcium ions in the molasses fermentation mash is 1.2-1.5:1.

[0013] Preferably, the alkali metal carbonate is sodium carbonate and / or potassium carbonate, preferably sodium carbonate.

[0014] Preferably, the alkali metal oxide is selected from calcium oxide; preferably, the alkali metal hydroxide is selected from one or more of calcium hydroxide, sodium hydroxide and potassium hydroxide, preferably sodium hydroxide.

[0015] Preferably, the pH of the precipitation reaction in step (1) is ≥11; preferably, the temperature of the precipitation reaction is 40-90°C, preferably 70-80°C; further preferably, the time of the precipitation reaction is 1-2h.

[0016] Preferably, the separation method in step (2) is selected from one or more of filtration, decantation and centrifugation, preferably centrifugation.

[0017] Preferably, the above-mentioned pretreatment method further comprises the step of ultrafiltration of the filtrate obtained in the step (2).

[0018] Preferably, the ultrafiltration membrane for ultrafiltration has a molecular weight cutoff of 50-150KD; preferably, the ultrafiltration membrane is a tubular ceramic membrane or a flat ceramic membrane, preferably a tubular ceramic membrane.

[0019] Preferably, the operating pressure of the ultrafiltration is 0.3-0.5 MPa; preferably, the ultrafiltration temperature is 50-80°C; further preferably, the flux is 30-40 L / m 2 / h.

[0020] Preferably, before the precipitation reaction, the method further comprises concentrating the molasses fermentation mash to obtain a molasses fermentation concentrate. Preferably, the dry matter content of the molasses fermentation concentrate is 30-80 wt%.

[0021] Preferably, the concentration process is carried out in an evaporator; preferably, the evaporator is a single-effect or multi-effect falling film evaporator, preferably a multi-effect falling film evaporator.

[0022] The present invention also provides a method for recovering betaine from molasses fermentation mash, comprising treating the molasses fermentation mash with the above-mentioned pretreatment method and then performing chromatography to obtain betaine.

[0023] Beneficial effects of the present invention:

[0024] (1) The pretreatment method for recovering betaine from molasses fermentation mash of the present invention uses alkali metal oxides or alkali metal hydroxides and alkali metal inorganic acid salts as precipitants, and quickly forms precipitates by regulating the process parameters of the precipitation reaction, and the removal rate of calcium and magnesium ions reaches more than 82%;

[0025] (2) The pretreatment method of the present invention is simple and efficient, greatly reducing the investment cost of pretreatment equipment, and the pretreatment time is less than 12 hours;

[0026] (3) The reagents used in this method are convenient and easy to obtain, with low cost, and the by-products produced, such as calcium carbonate, magnesium carbonate and calcium and magnesium hydroxide, are non-toxic, harmless and easy to handle;

[0027] (4) When the mother liquor obtained by the pretreatment method of the present invention is used for chromatography, the pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can be maintained relatively stable for more than 4 weeks. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and technical effect of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention is described clearly and completely. The embodiments described below are part of the embodiments of the present invention, not all of them. In combination with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Calcium and magnesium ions in molasses fermentation mash can cause scaling and clogging of chromatographic separation resins, shorten the cleaning cycle and service life of the resin, are not conducive to the long-term stable operation of the equipment, and reduce the production efficiency of the chromatographic separation system. Therefore, the higher the removal rate of calcium and magnesium ions in molasses fermentation mash, the higher the efficiency of subsequent chromatography system in extracting betaine from molasses fermentation mash. One of the purposes of the present invention is to provide a pretreatment method for recovering betaine from molasses fermentation mash, remove more than 82% of calcium and magnesium ions in molasses fermentation mash, and improve the efficiency of extracting betaine by the chromatography system.

[0030] In a specific embodiment, a pretreatment method for recovering betaine from molasses fermentation mash comprises the following steps:

[0031] (1) adding an alkali metal oxide or an alkali metal hydroxide and an alkali metal carbonate to the molasses fermentation mash to carry out a precipitation reaction, wherein the molar ratio of the alkali metal carbonate to the calcium ion in the molasses fermentation mash is 0.8-2.2:1, and the pH of the precipitation reaction is ≥10.5;

[0032] (2) Separating the reaction mixture of step (1) to remove solid impurities and obtain a filtrate.

[0033] The molasses fermentation mash in step (1) is the separated mash obtained by biologically fermenting betaine-containing crops and their hydrolysates to prepare fermentation products such as baker's yeast, alcohol, monosodium glutamate, citric acid and lysine. The betaine-containing crops include but are not limited to one or more of beets, wolfberries, soybeans, corn and wheat.

[0034] Before the precipitation reaction, the molasses fermentation mash is concentrated to a dry matter content of 30-80 wt%. The concentration process is carried out in an evaporator, which is a single-effect or multi-effect falling film evaporator, preferably a multi-effect falling film evaporator.

[0035] In a preferred embodiment of the present invention, the pretreatment method further comprises the step of ultrafiltration of the filtrate obtained in step (2). Ultrafiltration is used to further remove particulate matter such as calcium carbonate and magnesium hydroxide that have not been precipitated, thereby improving the efficiency of the chromatography system; preferably, after the ultrafiltration, the pH of the ultrafiltrate is adjusted to neutral to obtain a mother liquor, and the pH regulator used is selected from inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid.

[0036] The raw materials or reagents used in the present invention are all purchased from the mainstream manufacturers in the market. Those who do not indicate the manufacturer or those who do not indicate the concentration are all analytically pure raw materials or reagents that can be routinely obtained. As long as the expected effect can be played, there is no particular restriction. The instruments and equipment used in the present embodiment are all purchased from the main manufacturers in the market. As long as the expected effect can be played, there is no particular restriction. In the present embodiment, if specific techniques or conditions are not indicated, the techniques or conditions described in the documents in this area or according to the product specification are carried out.

[0037] The present invention will be described in detail below through specific embodiments and experimental examples.

[0038] Example 1

[0039] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0040] The fermented mash for producing baker's yeast with beet molasses as raw material is first concentrated by a multi-effect falling film evaporator to obtain a fermented concentrate with a dry matter content of 47.8%, wherein the calcium ion content based on the dry matter is 0.81%, and the magnesium ion content is 0.45%; 2.4 kg of the fermented concentrate is transferred to a reactor with a heat preservation and agitator, the temperature is raised to 70°C, sodium hydroxide is added to adjust the pH to 11.5, and 1.5 times the molar equivalent of calcium sodium carbonate is continuously added, and the reaction is stirred for 90 minutes. The mixed solution is passed through a horizontal screw centrifuge to remove insoluble solids to obtain a filtrate; the filtrate is heated to 70°C, and ultrafiltration is performed using a tubular ceramic membrane with a molecular weight cutoff of 100KD. The feed pressure of the tubular ceramic membrane is 0.35MPa, the temperature is 70°C, and the average flux is 33.5L / m 2 / h to obtain an ultrafiltrate, and then use 20% mass concentration hydrochloric acid to adjust the pH of the ultrafiltrate to neutral to obtain 2Kg of mother liquor.

[0041] The mother liquor was chromatographed using a simulated moving bed chromatography system to obtain a fraction containing betaine. The simulated moving bed chromatography system consists of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0042] The solid content, calcium ion content, magnesium ion content of the mother liquor and the solid content, purity and yield of the betaine-containing fraction were determined by the following methods.

[0043] 1. Solid content

[0044] Weigh about 6g of solution, accurate to 0.0002g, place in a weighing bottle with constant weight, shake carefully to allow the solution to flow naturally and form a uniform film at the bottom of the bottle. Place in a drying oven, gradually heat to 105℃, dry at (105±2℃) for 6 hours, take out and place in a desiccator, cool to room temperature, and weigh.

[0045] Calculation results:

[0046] The solid content X expressed as a mass percentage is calculated as follows:

[0047] X=[(M2-M1) / M]*100

[0048] Where: M1: mass of weighing bottle, g;

[0049] M2: mass of the solution and weighing bottle after drying, g;

[0050] M: mass of original solution, g.

[0051] 2. Calcium ion content

[0052] According to the determination method of calcium in GB / T 13885-2017:

[0053] 1) dry matter obtained according to the above solid content determination method;

[0054] 2) According to the estimated solid content, weigh 1-5g of the above dry matter sample, accurate to 1mg, put it into a crucible, place the crucible on a hot plate and heat it until the sample is completely carbonized (avoid burning of the sample), transfer the crucible to a high-temperature electric furnace preheated at 550℃ for more than 15min and ashed for 3h. After cooling, moisten the sample in the crucible with 2mL of water. If there are carbon particles, place the crucible on a hot plate and slowly and carefully evaporate it, then place it in a high-temperature resistance furnace and ashed again for 2h, and add 2mL of water to moisten the sample in the crucible after cooling.

[0055] 3) Take 10mL of 6mol / L hydrochloric acid solution, add it slowly drop by drop, and rotate the crucible while adding until there is no bubbling (carbon dioxide may be produced), then add it quickly, rotate the crucible and heat until the contents are almost dry, and avoid splashing the contents during heating. After heating and dissolving the residue with 5mL of 6mol / L hydrochloric acid, transfer the sample solution to a 50mL volumetric flask with about 5mL of water in batches, dilute with water to the fixed volume after cooling, and filter with filter paper.

[0056] 4) Prepare a blank solution according to steps 1) and 2) without adding any test material.

[0057] 5) Measurement conditions

[0058] The instrument test conditions of the atomic absorption spectrophotometer were adjusted so that the instrument was in the best analysis state under the air-acetylene flame measurement mode, and the measurement wavelength of calcium was 422.6 nm.

[0059] 6) Prepare standard solutions of Ca, K, Mg, and Na according to 4.10 of GB / T 13885-2017, dilute the standard solution with water, add 5 mL of lanthanum nitrate solution, 5 mL of cesium chloride solution, and 5 mL of 0.6 mol / L hydrochloric acid solution to every 100 mL of standard solution, and prepare a set of appropriate standard working solutions. Measure the absorbance of the lanthanum / cesium blank solution, measure the absorbance of the standard solution and subtract the absorbance of the lanthanum / cesium blank solution, and use the corrected absorbance to generate a standard curve for the Ca content.

[0060] 7) Quantitatively dilute the sample solution prepared in step 3) and the blank solution prepared in step 4) with water. For every 100 mL of solution, add 5 mL of lanthanum nitrate solution, 5 mL of cesium chloride solution and 5 mL of 0.6 mol / L hydrochloric acid solution. Under the same conditions, measure the absorbance of the sample solution and the blank solution. Subtract the absorbance of the blank solution from the absorbance of the sample solution. If necessary, dilute the sample solution and the blank solution with lanthanum / cesium blank solution so that their absorbances are within the linear range of the standard curve.

[0061] 8) Calculation of results

[0062] The Ca element in the sample is expressed as mass fraction ω, and the value is expressed as mg / kg, calculated as follows, and rounded according to Table 1:

[0063] ω=(c-c0)×50×N / m

[0064] Where:

[0065] c——the concentration of calcium in the sample solution, in micrograms per milliliter;

[0066] c0——the concentration of calcium in the blank solution, in micrograms per milliliter;

[0067] N——dilution multiple;

[0068] m – the mass of the sample, in grams.

[0069] Table 1 Results of calculations

[0070] content Round to 5-10 mg / kg 0.1mg / kg 10-100 mg / kg 1mg / kg 100-1000mg / kg 10mg / kg 1-10g / kg 100mg / kg 10-100g / kg 1g / kg

[0071] 3. Magnesium ion content

[0072] According to the calcium ion content test method, the difference is that the measurement wavelength of the atomic absorption spectrophotometer is 285.2nm.

[0073] 4. Betaine content, purity and yield

[0074] (1) Determine the betaine content according to the betaine determination method in GB / T 23710.

[0075] Weigh 2g of the sample, accurate to 0.0001g, place it in a 100mL volumetric flask, add about 80mL of water, mix, place on an oscillator and shake vigorously or ultrasonically extract for 30min, let stand for 10min, fix the volume, centrifuge or filter. Take 2mL of the filtrate in a centrifuge tube, add 2mL of chloroform, shake vigorously, place for 10min, centrifuge at 5000r / min for 10min, remove the supernatant, filter through a 0.45μm filter membrane, and then measure on the machine.

[0076] Chromatographic conditions: flow rate: 1.0 mL / min; column temperature: 40°C; injection volume: 10 μL-20 μL.

[0077] The betaine standard working solution was continuously injected into the ion chromatography (IC) analyzer until a chromatographic peak with a stable baseline, symmetrical peak shape and reproducible peak area was obtained.

[0078] The betaine content X1 in the sample is expressed in milligrams per kilogram (mg / kg) and is calculated according to the following formula:

[0079] X1=(C*V*1000) / M

[0080] Where:

[0081] C: The concentration of betaine in the test solution obtained from the standard curve, in milligrams per milliliter (mg / mL);

[0082] V: fixed volume, in milliliters (mL);

[0083] M: sample mass, in grams (g).

[0084] (2) Calculation method of betaine purity

[0085] The purity X2 of betaine in the sample is expressed in %, and is calculated as follows:

[0086] X2=X1 / (100*X)

[0087] Where:

[0088] X1: betaine content in solution (mg / kg);

[0089] X: solution solid content (%).

[0090] (3) Calculation method of betaine yield:

[0091] The yield of betaine in the sample, X3, is expressed in %, and is calculated as follows:

[0092] X3=100*W1 / W

[0093] Where:

[0094] W: betaine content in beet molasses fermentation concentrate (mg / kg);

[0095] W1: betaine content in ultrafiltrate (mg / kg).

[0096] The solid content of the betaine extract measured according to the above method is 21.46%, the purity is 86.5%, and the yield is 99.4%.

[0097] Example 2

[0098] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0099] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, heated to 80°C, sodium oxide was added to adjust the pH to 10.5, and potassium carbonate in an amount of 1.2 times the molar ratio of calcium was added, and the mixture was stirred for 60 minutes. The insoluble solids were removed from the mixed solution by a horizontal screw centrifuge to obtain a filtrate; the filtrate was heated to 50°C, and ultrafiltration was performed using a tubular ceramic membrane with a molecular weight cutoff of 50KD. The feed pressure of the tubular ceramic membrane was 0.5 MPa, the temperature was 50°C, and the average flux was 30 L / m 2 / h to obtain an ultrafiltrate, and then use 20% mass concentration hydrochloric acid to adjust the pH of the ultrafiltrate to neutral to obtain 2Kg of mother liquor.

[0100] The mother liquor is chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0101] The solid content, calcium ion content and magnesium ion content of the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0102] The solid content of betaine measured according to the method described in Example 1 was 20.93%, the purity was 84.9%, and the yield was 97.9%.

[0103] Example 3

[0104] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0105] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, the temperature was raised to 40°C, sodium hydroxide was added to adjust the pH to 11, and sodium carbonate in an amount of 1.3 times the molar ratio of calcium was continued to be added, and the reaction was stirred for 120 minutes. The mixed solution was centrifuged to remove insoluble solids to obtain a filtrate; the filtrate was heated to 80°C, and ultrafiltration was performed using a tubular ceramic membrane with a molecular weight cutoff of 150KD. The feed pressure of the tubular ceramic membrane was 0.3MPa, the temperature was 80°C, and the average flux was 40L / m 2 / h to obtain an ultrafiltrate, and then use 20% mass concentration hydrochloric acid to adjust the pH of the ultrafiltrate to neutral to obtain 2kg of mother liquor.

[0106] The mother liquor is chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0107] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0108] The solid content of betaine measured according to the method described in Example 1 was 20.58%, the purity was 86.49%, and the yield was 97.52%.

[0109] Example 4

[0110] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0111] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, and the temperature was raised to 90° C. Sodium hydroxide was added to adjust the pH to 12, and potassium carbonate with a molar equivalent of 1 times calcium was continuously added, and the reaction was stirred for 100 minutes. The mixed solution was centrifuged to remove insoluble solids to obtain a filtrate; the filtrate was heated to 60° C. and ultrafiltered using a tubular ceramic membrane with a molecular weight cutoff of 80 KDa. The feed pressure of the tubular ceramic membrane was 0.4 MPa, the temperature was 60° C., and the average flux was 35 L / m 2 / h to obtain an ultrafiltrate, and then use 20% mass concentration hydrochloric acid to adjust the pH of the ultrafiltrate to neutral to obtain 2kg of mother liquor.

[0112] The mother liquor is chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0113] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0114] The solid content of betaine measured according to the method described in Example 1 was 19.36%, the purity was 85.59%, and the yield was 93.5%.

[0115] Example 5

[0116] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0117] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, and the temperature was raised to 65° C. Sodium hydroxide was added to adjust the pH to 12.5, and potassium carbonate in an amount of 2 times the molar ratio of calcium was continuously added, and the reaction was stirred for 80 minutes. The mixed solution was centrifuged to remove insoluble solids to obtain a filtrate; the filtrate was heated to 65° C. and ultrafiltered using a tubular ceramic membrane with a molecular weight cutoff of 120 KD. The feed pressure of the tubular ceramic membrane was 0.45 MPa, the temperature was 65° C., and the average flux was 38 L / m 2 / h to obtain an ultrafiltrate, and then use 20% mass concentration hydrochloric acid to adjust the pH of the ultrafiltrate to neutral to obtain 2kg of mother liquor.

[0118] The mother liquor is chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0119] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0120] The solid content of betaine measured according to the method described in Example 1 was 19.3%, the purity was 85.7%, and the yield was 95.2%.

[0121] Example 6

[0122] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0123] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, and the temperature was raised to 70° C. Sodium hydroxide was added to adjust the pH to 11.5, and 0.8 times the molar equivalent of calcium sodium carbonate was added, and the reaction was stirred for 90 minutes. The mixed solution was centrifuged to remove insoluble solids to obtain a filtrate; the filtrate was heated to 70° C. and ultrafiltered using a tubular ceramic membrane with a molecular weight cutoff of 100 KD. The feed pressure of the tubular ceramic membrane was 0.35 MPa, the temperature was 70° C., and the average flux was 33.5 L / m 2 / h to obtain an ultrafiltrate, and then 20% mass concentration hydrochloric acid was used to adjust the pH of the ultrafiltrate to neutral to obtain 1.9 kg of mother liquor.

[0124] The mother liquor is chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0125] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0126] The solid content of betaine measured according to the method described in Example 1 was 19.4%, the purity was 85.3%, and the yield was 92.1%.

[0127] Example 7

[0128] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0129] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, heated to 65° C., sodium hydroxide was added to adjust the pH to 12.5, and potassium carbonate in an amount of 2.2 times the molar ratio of calcium was continued to be added, and the reaction was stirred for 80 minutes. The mixed solution was centrifuged to remove insoluble solids to obtain a filtrate; the filtrate was heated to 65° C. and ultrafiltered using a tubular ceramic membrane with a molecular weight cutoff of 120 KD. The feed pressure of the tubular ceramic membrane was 0.45 MPa, the temperature was 65° C., and the average flux was 38 L / m 2 / h to obtain an ultrafiltrate, and then 20% mass concentration hydrochloric acid was used to adjust the pH of the ultrafiltrate to neutral to obtain 1.9 kg of mother liquor.

[0130] The mother liquor is chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system can maintain a relatively stable time of more than 5 weeks.

[0131] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0132] The solid content of betaine measured according to the method described in Example 1 was 21.3%, the purity was 87.92%, and the yield was 99.1%.

[0133] Example 8

[0134] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0135] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, the temperature was raised to 70°C, sodium hydroxide was added to adjust the pH to 11.5, and 1.3 times the molar equivalent of calcium sodium carbonate was added, and the reaction was stirred for 90 minutes. The mixed solution was centrifuged to remove insoluble solids to obtain a filtrate; then 20% mass concentration hydrochloric acid was used to adjust the pH of the ultrafiltrate to neutral to obtain 2 kg of mother liquor.

[0136] The mother liquor was chromatographed using a simulated moving bed chromatography system to obtain the betaine product. The simulated moving bed chromatography system consists of multiple columns connected end to end, with a main circulation loop of water and materials inside. The standard automatic valve is switched according to the program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system remain relatively stable for about 4 weeks.

[0137] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0138] The solid content of betaine measured according to the method described in Example 1 was 18.5%, the purity was 76.8%, and the yield was 90.3%.

[0139] Comparative Example 1

[0140] The pretreatment method for recovering betaine from molasses fermentation mash is as follows:

[0141] 2.4 kg of the fermentation concentrate obtained in Example 1 was transferred to a reactor equipped with a heat preservation and agitator, and lime milk and CO2 were introduced into the fermentation concentrate. The concentration of the introduced CO2 was 38%, and the reaction system was saturated to pH 6.5. The reaction system was allowed to stand at 60 degrees for 2 hours, and the supernatant was filtered to obtain 2.2 kg of supernatant.

[0142] The supernatant was chromatographed using a simulated moving bed chromatography system to obtain a betaine product, wherein the simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside, and a standard automatic valve is switched according to a program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system remain relatively stable for about 1 week.

[0143] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0144] The solid content of betaine measured according to the method described in Example 1 was 35.7%, the purity was 74.8%, and the yield was 90.7%.

[0145] Comparative Example 2

[0146] The supernatant obtained in Comparative Example 1 was microfiltered through a ceramic membrane with a pore size of 0.05-0.1 um to obtain 2 kg of filtrate. The operating pressure of the microfiltration process was 0.3 MPa and the operating temperature was 40 degrees.

[0147] The filtrate was chromatographed using a simulated moving bed chromatography system to obtain a betaine product, wherein the simulated moving bed chromatography system is composed of multiple columns connected end to end, with a main circulation loop of water and materials inside, and a standard automatic valve is switched according to a program to simulate the reverse movement of the resin, thereby achieving the purpose of simulated movement. The pressure drop, resin capacity and separation characteristics of the resin used in the chromatography system remain relatively stable for about 2 weeks.

[0148] The solid content, calcium ion content and magnesium ion content in the mother liquor were tested according to the method described in Example 1. The results are shown in Table 2.

[0149] The solid content of betaine measured according to the method described in Example 1 was 34.8%, the purity was 93.4%, and the yield was 93.3%.

[0150] Table 2 Mother liquor test results

[0151]

[0152] As can be seen from Table 2, the fermentation mash pretreatment method of the present invention uses alkali metal oxides or alkali metal hydroxides and alkali metal inorganic acid salts as precipitants, and quickly forms precipitates by regulating the process parameters of the precipitation reaction, which can effectively remove calcium and magnesium ions in the fermentation mash, and the removal rate is more than 82%. The obtained mother liquor can be stably operated in a simulated moving bed chromatography system for more than 4 weeks; Examples 1-7 further perform ultrafiltration treatment on the filtrate, and the removal rate of calcium and magnesium ions reaches more than 87%. The obtained mother liquor can be stably operated in a simulated moving bed chromatography system for more than 5 weeks, and natural betaine with a purity of more than 80% can be obtained.

[0153] In summary, the pretreatment method of the present invention is simple and efficient, greatly reduces the investment cost of pretreatment equipment, and the pretreatment time is less than 12 hours; the reagents used in the method are convenient and easy to obtain, with low cost, and the by-products produced, such as calcium carbonate, magnesium carbonate and calcium and magnesium hydroxides, are non-toxic, harmless and easy to handle.

[0154] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pretreatment method for recovering betaine from molasses fermentation mash, characterized in that: The steps include: (1) adding alkali metal oxide or alkali metal hydroxide and alkali metal carbonate to molasses fermentation mash for precipitation reaction, wherein the molar ratio of the alkali metal carbonate to the calcium ion in the molasses fermentation mash is 0.8-2.2:1, the pH of the precipitation reaction is ≥10.5, and the temperature of the precipitation reaction is 40-90° C.; (2) separating the reaction mixture of step (1) to remove solid impurities to obtain a separated liquid, wherein the separation method is selected from one or more of filtration, decantation and centrifugation; (3) ultrafiltration of the separated liquid obtained in step (2), wherein the ultrafiltration membrane has a molecular weight cutoff of 50-150 KD; The molasses fermented mash is mash obtained by biological fermentation and separation of betaine-containing crops or hydrolyzates of betaine-containing crops.

2. The pretreatment method according to claim 1, characterized in that The betaine-containing crops are selected from one or more of beet, wolfberry, soybean, corn and wheat.

3. The pretreatment method according to claim 1, characterized in that: The molar ratio of the alkali metal carbonate to the calcium ions in the molasses fermentation mash is 1.2-1.5:

1.

4. The pretreatment method according to claim 1, characterized in that: The alkali metal carbonate is sodium carbonate and / or potassium carbonate.

5. The pretreatment method according to claim 4, characterized in that: The alkali metal carbonate is sodium carbonate.

6. The pretreatment method according to claim 1, characterized in that: The pH of the precipitation reaction in step (1) is ≥11.

7. The pretreatment method according to claim 3, characterized in that: The pH of the precipitation reaction in step (1) is ≥11.

8. The pretreatment method according to claim 1, characterized in that: The temperature of the precipitation reaction is 70-80°C.

9. The pretreatment method according to claim 8, characterized in that: The precipitation reaction time is 1-2h.

10. The pretreatment method according to claim 3, characterized in that: The temperature of the precipitation reaction is 70-80°C.

11. The pretreatment method according to claim 6, characterized in that: The temperature of the precipitation reaction is 70-80°C.

12. The pretreatment method according to claim 1, characterized in that: The separation method in step (2) is centrifugation.

13. The pretreatment method according to any one of claims 1 to 12, characterized in that: The ultrafiltration membrane is a tubular ceramic membrane or a flat ceramic membrane.

14. The pretreatment method according to claim 13, characterized in that: The ultrafiltration membrane is a tubular ceramic membrane.

15. The pretreatment method according to any one of claims 1 to 12, characterized in that: The operating pressure of the ultrafiltration is 0.3-0.5 MPa.

16. The pretreatment method according to claim 15, characterized in that: The temperature of the ultrafiltration is 50-80°C.

17. The pretreatment method according to claim 16, characterized in that: Flux is 30-40L / m 2 / h.

18. The pretreatment method according to claim 13, characterized in that: The operating pressure of the ultrafiltration is 0.3-0.5 MPa.

19. The pretreatment method according to any one of claims 1 to 12, characterized in that: Before the precipitation reaction, the molasses fermentation mash is concentrated to obtain molasses fermentation concentrate.

20. The pretreatment method according to claim 19, characterized in that: The dry matter content of the molasses fermentation concentrate is 30-80 wt %.

21. The pretreatment method according to claim 20, characterized in that: The concentration process is carried out in an evaporator.

22. The pretreatment method according to claim 21, characterized in that: The evaporator is a single-effect or multi-effect falling film evaporator.

23. A method for recovering betaine from molasses fermentation mash, characterized in that: The method comprises treating molasses fermentation mash with the pretreatment method described in any one of claims 1 to 22 and then performing chromatography to obtain betaine.

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