A method for recovering inositol and amino acid substances from inositol crystallization mother liquor

Abstract

The invention discloses a method for recovering inositol and amino acid substances from inositol crystallization mother liquor, comprising the following steps: pumping the inositol crystallization mother liquor into a simulated mobile chromatography system, using water as a mobile phase, separating to obtain an inositol solution and an amino acid solution containing inorganic salts; cooling and crystallizing the inositol solution after vacuum concentration to obtain an inositol crude product, adding water to the inositol crude product to dissolve it again, adding activated carbon for decolorization treatment and cooling and crystallizing to obtain an inositol finished product; sequentially performing nanofiltration membrane concentration and multi-effect evaporator vacuum concentration on the amino acid solution containing inorganic salts, followed by decolorization and filtration, and spray drying the collected filtrate to obtain amino acid powder. The method provided by the invention is simple to operate, can recover inositol and amino acid powder from waste liquid, not only effectively reduces the pollution of the inositol crystallization mother liquor to the environment, but also realizes the reuse of waste resources, and achieves the purpose of energy saving and emission reduction.

Description

Technical Field

[0001] The invention relates to the technical field of inositol production, and in particular to a method for recovering inositol and amino acid substances from inositol crystallization mother liquor. Background Art

[0002] Inositol, chemical name: cyclohexanehexol, is an important vitamin required by higher animals. Inositol can promote fat metabolism and reduce the cholesterol content in the blood. It is also used as an anti-fatty liver drug for the treatment of cirrhosis, hepatitis, high cholesterol, excessive fat and vascular sclerosis. In addition to being used directly as a drug, such as inositol tablets, hepatol, and liver-soothing tablets, inositol is also used as a pharmaceutical intermediate to make many drugs, such as inositol nicotinate, Maitong, and the anticancer drug paclitaxel.

[0003] At present, inositol production mostly uses phytate as raw material, which is hydrolyzed to obtain inositol and phosphate. After inositol is separated from phosphate, the finished inositol is obtained through processes such as concentration, crystallization, decolorization, and recrystallization. Since phytate is mostly derived from plants, such as corn, rice bran, wheat bran, etc., plant protein will be entrained during the production of phytate, and the maximum content can reach 10-15%. During the hydrolysis of phytate, protein is also decomposed to produce a large amount of amino acid substances. Amino acid substances are well water-soluble. During the process of inositol concentration, crystallization, and recrystallization, they are gradually enriched and remain in the inositol crystallization mother liquor. When the amino acid concentration in the mother liquor is too high, it will cause inositol to be unable to crystallize. This mother liquor can only be discharged as wastewater, which not only causes environmental pollution, but also causes inositol loss. Amino acids have a wide range of applications. They can provide more comprehensive nutrition for plants and can be used as raw materials for foliar fertilizer, concentrated fertilizer, and liquid fertilizer. They can supplement the nutrients lost during the processing of fish meal, which is beneficial for aquatic animals to absorb and utilize. They are suitable for aquatic animals to eat and grow quickly. Special aquatic products can replace fish meal to save costs and achieve significant results. They can promote the growth of livestock and poultry fur, make pigs' skin ruddy and their fur shiny, and increase the color of broilers' fur and the color of their combs and feet. How to recover inositol from the crystallization mother liquor and recover composite amino acids is of great research significance. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the deficiencies in the prior art, a method for recovering inositol and amino acid substances from inositol crystallization mother liquor is provided. The method firstly pumps the inositol crystallization mother liquor into a simulated mobile chromatography system, separates the inositol solution and the amino acid solution containing inorganic salts, and then post-treats the two solutions respectively to obtain finished inositol and composite amino acid powder. The operation is simple, and the pollution of the inositol crystallization mother liquor to the environment is effectively reduced, the reuse of waste resources is realized, and the purpose of energy saving and emission reduction is achieved.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for recovering inositol and amino acid substances from inositol crystallization mother liquor comprises the following steps:

[0007] (1) cooling and crystallizing the inositol concentrated solution, centrifuging to obtain an inositol crude product and a crude product mother liquor, subjecting the crude inositol to dissolution and decolorization, recrystallization, centrifugation, and drying steps to obtain an inositol finished product, mixing part of the crude product mother liquor with the inositol concentrated solution for the next round of cooling and crystallization, and the remaining crude product mother liquor is the inositol crystallization mother liquor; pumping the inositol crystallization mother liquor into a simulated mobile chromatography system, using water as a mobile phase, and performing separation to obtain an inositol solution and an amino acid solution containing an inorganic salt;

[0008] (2) vacuum concentrating the obtained inositol solution and cooling and crystallizing it to obtain a crude inositol product, adding water to the crude inositol product to redissolve it, adding activated carbon for decolorization, and then continuing to cool and crystallize it, and drying and sieving the solid after crystallization to obtain a finished inositol product;

[0009] (3) subjecting the obtained amino acid solution containing inorganic salts to nanofiltration membrane concentration treatment, collecting the nanofiltration membrane concentrate, pumping the nanofiltration membrane concentrate into a multi-effect evaporator for further concentration to obtain a vacuum concentrate, adding activated carbon to the vacuum concentrate for heat preservation and decolorization treatment, and then filtering to collect the filtrate;

[0010] (4) The filtrate collected in step (3) is transported to a spray drying tower via a diaphragm pump for spray drying to obtain amino acid powder.

[0011] As a preferred embodiment of the above technical solution, in step (1), the inositol crystallization mother liquor is collected from the inositol crystallization process, and the solid content of the inositol crystallization mother liquor is 15-30%.

[0012] As a preferred embodiment of the above technical solution, in step (1), the temperature during separation is 50-60°C and the pressure is 0.1-0.3 MPa.

[0013] As a preferred embodiment of the above technical solution, in step (1), during separation, the volume ratio of the feed amount of inositol crystallization mother liquor to the mobile phase is 1:(2-4), the flow rate of the inositol crystallization mother liquor is 30-60 L / h, and the flow rate of the mobile phase is 120-180 L / h. During separation, the inositol solution and the amino acid solution containing inorganic salts are collected separately by valve switching, and the valve switching time is 10 min.

[0014] As a preferred embodiment of the above technical solution, in step (2), a four-effect concentrator is used for vacuum concentration, the vacuum degree during concentration is -0.07 to -0.09 MPa, the temperature is 80-90°C, and the solid content of the concentrated liquid is 30-45%.

[0015] As a preferred embodiment of the above technical solution, in step (2), when the crude inositol is redissolved in water, the mass ratio of the crude inositol to water is 1:(2-3), and the amount of activated carbon used for decolorization is 2-5% of the weight of the crude inositol.

[0016] As a preferred embodiment of the above technical solution, in step (3), the molecular weight cutoff of the nanofiltration membrane is 200 Da1; the vacuum degree when the nanofiltration membrane concentrate is pumped into the multi-effect evaporator for further concentration is -0.07 to -0.085 MPa, the temperature is 75-85°C, the solid content of the nanofiltration membrane concentrate is 20-30%, and the solid content of the vacuum concentrate is 40-50%.

[0017] As a preferred embodiment of the above technical solution, in step (3), the amount of activated carbon used during thermal insulation and decolorization is 10-30 g / L, the thermal insulation and decolorization temperature is 70-80°C, and the time is 0.5-1h.

[0018] As a preferred embodiment of the above technical solution, in step (3), a candle filter and a precision filter are used for filtering in sequence; the filter cloth of the candle filter is 400-500 mesh, and the pore size of the filter element of the precision filter is 1-5 μm.

[0019] As a preferred embodiment of the above technical solution, in step (4), the air inlet temperature during spray drying is 150-170°C, and the air outlet temperature is 60-80°C.

[0020] In the present invention, the mass ratio of the crude mother liquor mixed with the inositol concentrated solution for the next round of cooling crystallization and the crude mother liquor used as the inositol crystallization mother liquor is (6-8): (2-4).

[0021] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] The invention mixes part of the crude mother liquor obtained after cooling and crystallizing the inositol concentrated liquid with the inositol concentrated liquid again for the next round of cooling and crystallization treatment, and another part is used as the inositol crystallization mother liquor for the next step treatment, thereby improving the inositol yield.

[0023] The present invention pumps the inositol crystallization mother liquor into a simulated moving bed chromatography system for treatment to obtain an inositol solution and an amino acid solution containing inorganic salts, the inositol solution is sequentially concentrated, decolorized, and crystallized to obtain an inositol product, and the amino acid solution containing inorganic salts is firstly treated with a nanofiltration membrane to remove salt substances, the obtained amino acid solution is vacuum concentrated, decolorized with activated carbon, and finally spray-dried to obtain an amino acid substance powder; the above method is easy to operate, and the amino acid substances and inositol in the inositol crystallization mother liquor can be effectively recovered, and the purity of the obtained inositol is ≥99.5%, thereby improving the yield of inositol. The present invention reuses the inositol crystallization and recrystallization crystallization mother liquor, which not only realizes the reuse of waste resources, but also avoids wastewater discharge and pollution of the environment. The amino acid substance obtained by the present invention is a light yellow powder, which is uniform and has no agglomeration, has the inherent smell and taste of the product, has no peculiar smell or odor, has an amino acid purity of ≥80%, and has a moisture content of 3-5%, has a broad market prospect, and has significant economic benefits. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0025] Example 1

[0026] (1) After cooling and crystallizing the inositol concentrate, centrifugation is performed to obtain an inositol crude product and a crude product mother liquor. The crude inositol is subjected to dissolution and decolorization, recrystallization, centrifugation, and drying processes to obtain an inositol finished product. 70% by weight of the crude product mother liquor is mixed with the inositol concentrate again for the next round of cooling and crystallization. The remaining crude product mother liquor is the inositol crystallization mother liquor, which is pumped into a simulated mobile chromatography system, and water is used as a mobile phase for separation. During separation, the volume ratio of the crystallization mother liquor feed amount to the mobile phase is controlled to be 1:2. During separation, the temperature is 50° C., the pressure is 0.1 MPa, the flow rate of the inositol crystallization mother liquor is 30 L / h, and the flow rate of the mobile phase is 120 L / h. During separation, the inositol solution and the amino acid solution are collected separately by switching the valve, and the valve switching time is 10 min;

[0027] (2) placing the obtained inositol solution in a four-effect concentrator, and performing vacuum concentration under the conditions of a vacuum degree of -0.07 MPa and a temperature of 80-90° C. to obtain a concentrated solution with a solid content of 30-45%, cooling the concentrated solution for crystallization to obtain a crude inositol product, mixing the crude inositol product with water in a mass ratio of 1:2 and stirring until the solid is dissolved, and adding activated carbon in an amount of 2% by weight of the crude inositol product for decolorization, and then continuing to cool and crystallize, and drying and sieving the crystallized solid to obtain a finished inositol product;

[0028] (3) The obtained amino acid solution containing inorganic salts is concentrated using a nanofiltration membrane with a molecular weight cutoff of 200 Da1 to obtain a nanofiltration membrane concentrate with a solid content of 20-30%, and the nanofiltration membrane concentrate is pumped into a multi-effect evaporator for further concentration under the conditions of a vacuum degree of -0.07 MPa and a temperature of 75°C to obtain a vacuum concentrate with a solid content of 40-50%, and activated carbon is added to the vacuum concentrate at a concentration of 10 g / L. The concentrated solution is subjected to a heat preservation and decolorization treatment at 70°C for 1 hour, and then filtered using a candle filter with a filter cloth of 400-500 mesh and a precision filter with a filter element pore size of 1 μm, and the filtrate is collected;

[0029] (4) The filtrate collected in step (3) is transported to a spray drying tower via a diaphragm pump for spray drying to obtain amino acid powder. The inlet air temperature during spray drying is 150° C. and the outlet air temperature is 60° C.

[0030] Example 2

[0031] (1) After cooling and crystallizing the inositol concentrate, centrifugation is performed to obtain an inositol crude product and a crude product mother liquor. The crude inositol is subjected to dissolution and decolorization, recrystallization, centrifugation, and drying steps to obtain an inositol finished product. 70% by weight of the crude product mother liquor is mixed with the inositol concentrate again for the next round of cooling and crystallization treatment. The remaining crude product mother liquor is the inositol crystallization mother liquor, which is pumped into a simulated mobile chromatography system, and water is used as a mobile phase for separation. During separation, the volume ratio of the crystallization mother liquor feed amount to the mobile phase is controlled to be 1:4. During separation, the temperature is 60° C., the pressure is 0.3 MPa, the flow rate of the inositol crystallization mother liquor is 60 L / h, and the flow rate of the mobile phase is 180 L / h. During separation, the inositol solution and the amino acid solution are collected separately by switching the valve, and the valve switching time is 10 min;

[0032] (2) placing the obtained inositol solution in a four-effect concentrator, and performing vacuum concentration under the conditions of a vacuum degree of -0.09 MPa and a temperature of 90° C. to obtain a concentrated solution with a solid content of 30-45%, cooling the concentrated solution for crystallization to obtain a crude inositol product, mixing the crude inositol product with water in a mass ratio of 1:3 and stirring until the solid is dissolved, and adding activated carbon in an amount of 5% by weight of the crude inositol product for decolorization, and then continuing to cool and crystallize, and drying and sieving the crystallized solid to obtain a finished inositol product;

[0033] (3) The obtained amino acid solution containing inorganic salts is concentrated using a nanofiltration membrane with a molecular weight cutoff of 200 Da1 to obtain a nanofiltration membrane concentrate with a solid content of 20-30%, and the nanofiltration membrane concentrate is pumped into a multi-effect evaporator for further concentration under the conditions of a vacuum degree of -0.085 MPa and a temperature of 85°C to obtain a vacuum concentrate with a solid content of 40-50%, and activated carbon is added to the vacuum concentrate at a concentration of 30 g / L. The concentrated solution is subjected to a heat preservation and decolorization treatment at 80°C for 1 hour, and then filtered using a candle filter with a filter cloth of 400-500 mesh and a precision filter with a filter element pore size of 5 μm, and the filtrate is collected;

[0034] (4) The filtrate collected in step (3) is transported to a spray drying tower via a diaphragm pump for spray drying to obtain amino acid powder. The inlet air temperature during spray drying is 170° C. and the outlet air temperature is 80° C.

[0035] Example 3

[0036] (1) After cooling and crystallizing the inositol concentrate, centrifugation is performed to obtain a crude inositol product and a crude mother liquor. The crude inositol product is subjected to dissolution and decolorization, recrystallization, centrifugation, and drying steps to obtain a finished inositol product. 70% by weight of the crude mother liquor is mixed with the inositol concentrate again for the next round of cooling and crystallization treatment. The remaining crude mother liquor is the inositol crystallization mother liquor, which is pumped into a simulated mobile chromatography system, and water is used as a mobile phase for separation. During separation, the volume ratio of the crystallization mother liquor feed amount to the mobile phase is controlled to be 1:3. During separation, the temperature is 50° C., the pressure is 0.2 MPa, the flow rate of the inositol crystallization mother liquor is 40 L / h, and the flow rate of the mobile phase is 130 L / h. During separation, the inositol solution and the amino acid solution are collected separately by switching the valve, and the valve switching time is 10 min;

[0037] (2) placing the obtained inositol solution in a four-effect concentrator, vacuum concentrating the solution under the conditions of a vacuum degree of -0.07 MPa and a temperature of 80° C. to obtain a concentrated solution with a solid content of 30-45%, cooling the concentrated solution for crystallization to obtain a crude inositol product, mixing the crude inositol product with water in a mass ratio of 1:2 and stirring until the solid is dissolved, adding 3% of the weight of the crude inositol product in activated carbon for decolorization, and then continuing to cool and crystallize, and drying and sieving the crystallized solid to obtain a finished inositol product;

[0038] (3) The obtained amino acid solution containing inorganic salts is concentrated using a nanofiltration membrane with a molecular weight cutoff of 200 Da1 to obtain a nanofiltration membrane concentrate with a solid content of 20-30%, and the nanofiltration membrane concentrate is pumped into a multi-effect evaporator for further concentration under the conditions of a vacuum degree of -0.08 MPa and a temperature of 80°C to obtain a vacuum concentrate with a solid content of 40-50%, and activated carbon is added to the vacuum concentrate at a concentration of 20 g / L. The concentrated solution is subjected to a heat preservation and decolorization treatment at 70-80°C for 1 hour, and then filtered using a candle filter with a filter cloth of 400-500 mesh and a precision filter with a filter element pore size of 2 μm, and the filtrate is collected;

[0039] (4) The filtrate collected in step (3) is transported to a spray drying tower via a diaphragm pump for spray drying to obtain amino acid powder. The inlet air temperature during spray drying is 160° C. and the outlet air temperature is 70° C.

[0040] Example 4

[0041] (1) After cooling and crystallizing the inositol concentrate, centrifugation is performed to obtain a crude inositol product and a crude mother liquor. The crude inositol product is subjected to dissolution and decolorization, recrystallization, centrifugation, and drying steps to obtain an inositol finished product. 70% by weight of the crude mother liquor is mixed with the inositol concentrate again for the next round of cooling and crystallization treatment. The remaining crude mother liquor is the inositol crystallization mother liquor, which is pumped into a simulated mobile chromatography system, and water is used as a mobile phase for separation. During separation, the volume ratio of the crystallization mother liquor feed amount to the mobile phase is controlled to be 1:4. During separation, the temperature is 50° C., the pressure is 0.2 MPa, the flow rate of the inositol crystallization mother liquor is 55 L / h, and the flow rate of the mobile phase is 170 L / h. During separation, the inositol solution and the amino acid solution are collected separately by switching the valve, and the valve switching time is 10 min;

[0042] (2) placing the obtained inositol solution in a four-effect concentrator, vacuum concentrating the solution under the conditions of a vacuum degree of -0.08 MPa and a temperature of 80° C. to obtain a concentrated solution with a solid content of 30-45%, cooling the concentrated solution for crystallization to obtain a crude inositol product, mixing the crude inositol product with water at a mass ratio of 1:3 and stirring until the solid is dissolved, adding activated carbon in an amount of 4% by weight of the crude inositol product for decolorization, and then continuing to cool and crystallize, and drying and sieving the crystallized solid to obtain a finished inositol product;

[0043] (3) The obtained amino acid solution containing inorganic salts is concentrated using a nanofiltration membrane with a molecular weight cutoff of 200 Da1 to obtain a nanofiltration membrane concentrate with a solid content of 20-30%, and the nanofiltration membrane concentrate is pumped into a multi-effect evaporator for further concentration under the conditions of a vacuum degree of -0.08 MPa and a temperature of 75°C to obtain a vacuum concentrate with a solid content of 40-50%, and activated carbon is added to the vacuum concentrate at a concentration of 25 g / L. The concentrated solution is subjected to a heat preservation and decolorization treatment at 80°C for 1 hour, and then filtered using a candle filter with a filter cloth of 400-500 mesh and a precision filter with a filter element pore size of 4 μm, and the filtrate is collected;

[0044] (4) The filtrate collected in step (3) is transported to a spray drying tower via a diaphragm pump for spray drying to obtain amino acid powder. The inlet air temperature during spray drying is 165° C. and the outlet air temperature is 70° C.

[0045] Comparative Example

[0046] The crude mother liquor after the inositol concentrate was cooled and crystallized was not subjected to subsequent treatment, and other conditions were the same as those in Example 4.

[0047] The cooling crystallization, dissolution decolorization, and recrystallization steps described in the above embodiments and comparative examples all adopt known conditions and parameters in the inositol production process in the art, so they will not be described in detail.

[0048] The purity of the inositol recovered in the method provided in the above embodiment is ≥99.5%, and the amount of inositol recovered per cubic meter of inositol crystallization mother liquor is 60-80 kg, which greatly improves the yield of inositol. The yield of inositol in Examples 1 to 4 is more than 97%, and the yield of inositol in the comparative example is 87.5%. The yield of inositol in the method provided by the present invention is significantly improved.

[0049] The amino acid substance recovered in the method provided in the above embodiment is a light yellow powder, which is uniform and free of agglomerates, has the inherent smell and taste of amino acids, has no peculiar smell or odor, has an amino acid purity of ≥80%, and has a moisture content of 3-5%.

[0050] In addition, it should be understood that after reading the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor, characterized in that: The following steps are involved: (1) After cooling and crystallizing the inositol concentrate, centrifugation is performed to obtain a crude inositol product and a crude mother liquor. The crude inositol product is subjected to dissolution and decolorization, recrystallization, centrifugation, and drying processes to obtain a finished inositol product. Part of the crude mother liquor and the inositol concentrate are mixed for the next round of cooling and crystallization, and the remaining crude mother liquor is the inositol crystallization mother liquor. The inositol crystallization mother liquor is pumped into a simulated mobile chromatography system, and water is used as a mobile phase for separation to obtain an inositol solution and an amino acid solution containing inorganic salts. The temperature during separation is 50-60°C, the pressure is 0.1-0.3MPa, the volume ratio of the inositol crystallization mother liquor feed amount to the mobile phase is 1:(2-4), the flow rate of the inositol crystallization mother liquor is 30-60L / h, and the flow rate of the mobile phase is 120-180L / h. During separation, the inositol solution and the amino acid solution containing inorganic salts are collected separately by valve switching, and the valve switching time is 10min. (2) vacuum concentrating the obtained inositol solution and cooling and crystallizing it to obtain a crude inositol product, adding water to the crude inositol product to redissolve it, adding activated carbon for decolorization, and then cooling and crystallizing it. The crystallized solid is dried and sieved to obtain a finished inositol product; (3) Concentrating the obtained amino acid solution containing inorganic salts with a nanofiltration membrane, collecting the nanofiltration membrane concentrate, pumping the nanofiltration membrane concentrate into a multi-effect evaporator for further concentration to obtain a vacuum concentrate, adding activated carbon to the vacuum concentrate for heat preservation and decolorization, and then filtering to collect the filtrate; (4) The filtrate collected in step (3) is transported to a spray drying tower via a diaphragm pump for spray drying to obtain amino acid powder.

2. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (1), the solid content of the inositol crystallization mother liquor is 15-30%.

3. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (2), a four-effect concentrator is used for vacuum concentration, the vacuum degree during concentration is -0.07~-0.09MPa, the temperature is 80-90°C, and the solid content of the concentrated liquid is 30-45%.

4. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (2), when the crude inositol is redissolved in water, the mass ratio of the crude inositol to water is 1:(2-3), and the amount of activated carbon used for decolorization is 2-5% of the weight of the crude inositol.

5. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (3), the molecular weight cutoff of the nanofiltration membrane is 200 Da1; the vacuum degree when the nanofiltration membrane concentrate is pumped into the multi-effect evaporator for further concentration is -0.07~-0.085 MPa, the temperature is 75-85°C, the solid content of the nanofiltration membrane concentrate is 20-30%, and the solid content of the vacuum concentrate is 40-50%.

6. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (3), the amount of activated carbon used during thermal insulation decolorization is 10-30 g / L, the thermal insulation decolorization temperature is 70-80°C, and the time is 0.5-1 h.

7. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (3), a candle filter and a precision filter are used for filtering in sequence; the filter cloth of the candle filter is 400-500 mesh, and the filter element pore size of the precision filter is 1-5 μm.

8. A method for recovering inositol and amino acid substances from inositol crystallization mother liquor according to claim 1, characterized in that: In step (4), the air inlet temperature during spray drying is 150-170°C, and the air outlet temperature is 60-80°C.