An energy-saving and emission-reduction process for VB12 extraction

Abstract

The present invention relates to the field of protein extraction production technology, and proposes an energy-saving and emission-reduction process for VB12 extraction, comprising the following steps: S1, subjecting a VB12 hydrolyzate to plate-and-frame filtration to obtain a first filtrate; S2, subjecting the first filtrate to low-pressure, lateral-flow tubular fine filtration to obtain a fine filtrate; S3, adsorbing the fine filtrate with a protein-targeted adsorbent to obtain a high-resolution solution; S4, subjecting the high-resolution solution to medium-pressure nanofiltration to obtain a nanofiltration concentrate, and then adsorbing protein impurities therein with a protein-targeted adsorbent to obtain a low-protein nanofiltration concentrate; S5, adding sodium cyanide to the low-protein nanofiltration concentrate for conversion to obtain a conversion supernatant; S6, subjecting the conversion supernatant to adsorption with an adsorption column, washing with water, and decomposing with acetone to obtain a secondary hydrolysis-refined concentrate; S7, subjecting the secondary hydrolysis-refined concentrate to chromatography and evaporation and crystallization to obtain pure VB12. The above technical solution solves the problems of high investment, high energy consumption, and difficulty in detoxification treatment in the prior art of VB12 production.

Description

Technical Field

[0001] The present invention relates to the technical field of protein extraction, and in particular to an energy-saving and emission-reduction process for extracting VB12. Background Art

[0002] Protein extraction is an unavoidable process in the production of fermentation products (such as antibiotics, vitamins, amino acids, acarbose, citric acid, lactic acid, and malic acid) and enzymatic hydrolysis products (such as heparin sodium). In many engineering designs, protein interference leads to poor membrane filtration performance, resulting in low flux, frequent backwashing, and a disproportionate investment and efficiency. The fundamental reasons for this are a lack of awareness of the harmful effects of protein and a lack of thorough protein removal processes.

[0003] Vitamin B12 (VB12) is a B vitamin composed of cobalt-containing porphyrin compounds. Its molecular structure is a nucleotide consisting of a corrin ring centered on a cobalt ion and 5,6-dimethylbenzimidazole as a base. The industrial production of VB12 generally involves aerobic fermentation with Pseudomonas denitrificans to produce an adenosylcobalamin fermentation broth. This broth is then filtered, adsorbed, analyzed, converted, and purified to obtain the final product.

[0004] When filtering adenosylcobalamin fermentation broth, many manufacturers use the following filtration methods during large-scale production: ① Plate and frame filtration; ② Rotary drum centrifuge filtration; and ③ Full membrane graded filtration. Of these filtration methods, plate and frame filtration remains the mainstream choice. Its advantages include clearer filtrate and a filter cake moisture content of ≤15% due to high extrusion pressure. This low filter cake moisture content facilitates subsequent drying of mycelium. Rotary drum centrifuge filtration requires excessive centrifugal power, resulting in high energy consumption. Finally, full membrane graded filtration results in a protein porridge with a moisture content of >75%. Unless directly used for secondary fermentation, this porridge must be dried for mycelium, as its high moisture content consumes too much energy.

[0005] Many manufacturers have added medium- and high-pressure membrane filtration behind the plate and frame, achieving excellent results at pressures above 0.6 MPa. However, this filtration combination presents a problem: when the medium- and high-pressure membranes operate, the high speed, high pressure, and high flow rate create high-pressure, strong shear stresses. The circulating material heats up within the membrane, and the real harm lies in the unstable breakage of numerous protein chains under shear, which reduces the molecular weight of large proteins and makes subsequent protein removal more difficult. The porridge-like proteins in the membrane phase are almost ineffectively intercepted when they return to the plate and frame, requiring the addition of larger doses of longer-chain flocculants for effectiveness.

[0006] After the filtration stage, a methacrylic acid macroporous cationic resin (referred to as a column in the industry) is used, from the early Amberlite IRC-50, HT-150, CAD-50 to the current Cobalamion. Although the use of dilute ammonia water for analysis is very good, the following problems exist: a. The expansion is too high, generally reaching an expansion rate of 80-120%; b. The volume of the analysis liquid is too large, about 2-3 times the volume of the adsorption bed (VB), and the enriched VB12 adenosine is diluted again; c. Under alkaline conditions, adenosine VB12 has very poor stability; d. The subsequent ammonia recovery process consumes high energy, and the residual ammonia nitrogen after all treatments is too high, making it difficult to directly conduct biochemical analysis; e. The effect of using other alkaline substitutes is not good; f. The high protein concentration has a strong competitive advantage over the ultra-low concentration of VB12 adenosine in the adsorption of cationic resins; g. High protein consumes most of the conversion agent - cyanide - when converting VB12 adenosine, and cyanide combines with protein to produce a large amount of cyanide-containing toxic hyphae.

[0007] After one column section, conversion filtration is performed, and the filtrate is the conversion clear liquid. Since the protein concentration in the conversion clear liquid is high and the VB12 concentration is low, when sodium cyanide is used for conversion, the molar ratio of sodium cyanide to adenosylcobalamin is 60-120:1. The excess cyanide-containing toxic waste and toxic mycelium are difficult to treat and the treatment time is long.

[0008] The supernatant is then passed through an adsorption column (referred to as the second column) and a chromatography column (referred to as the third column). The adsorption column uses acetone for desorption, while the chromatography column uses an acetone-water solution for chromatography. This requires processing a large amount of acetone-water, but the total amount recovered is relatively small. Furthermore, the resulting acetone-water solution requires evaporation, which consumes a lot of energy.

[0009] Therefore, it is urgent to develop an energy-saving and emission-reducing process for VB12 extraction to solve the above problems. Summary of the Invention

[0010] The present invention proposes an energy-saving and emission-reduction process for refining VB12, which solves the problems of high energy consumption and difficult post-processing in the production of VB12 in the prior art.

[0011] The technical solutions of the present invention are as follows:

[0012] A VB12 refining energy-saving and emission-reduction process comprises the following steps:

[0013] S1, Plate and frame filtration

[0014] The VB12 hydrolyzate is subjected to plate-and-frame filtration to obtain a first filtrate;

[0015] S2, low pressure, side flow fine filtration

[0016] The first filtrate is subjected to low-pressure, side-flow tubular fine filtration to obtain a fine filtrate;

[0017] S3. Protein targeted adsorption

[0018] The semen filtrate is adsorbed by a protein-targeted adsorbent to obtain a high-definition liquid;

[0019] S4, medium pressure nanofiltration

[0020] The high-resolution solution is subjected to medium-pressure nanofiltration to obtain a nanofiltration concentrate; and protein impurities in the nanofiltration concentrate are adsorbed by a protein-targeted adsorbent to obtain a low-protein nanofiltration concentrate;

[0021] S5. Conversion

[0022] adding sodium cyanide to the low-protein nanofiltration concentrate for conversion to obtain a conversion clear solution;

[0023] S6, adsorption column adsorption

[0024] The transformed clear solution is adsorbed on an adsorption column, washed with water and analyzed with acetone to obtain a secondary refined concentrated solution;

[0025] S7, chromatography, concentration, evaporation and crystallization

[0026] The concentrated solution from the second solution was concentrated by chromatography and evaporated for crystallization to obtain pure VB12.

[0027] As a further technical solution, in S2, during low-pressure, side-flow fine filtration, the pressure is 0.08-0.16 MPa, and the angle between the inflow direction of the first filtrate and the outflow direction of the fine filtrate is 100°-150°.

[0028] As a further technical solution, in S3, after the protein-targeted adsorbent is adsorbed, the protein-targeted adsorbent is heated and resolved with an alcohol solution at a heating temperature of 40-56°C to obtain a resolved concentrated solution and a resolved diluted solution. The resolved concentrated solution is cold-precipitated to obtain a supernatant and a precipitate. The precipitate is filtered to obtain a filtrate and a filter cake. The supernatant, the filtrate and the resolved diluted solution are combined into an alcohol resolved solution, which is circulated for heating and resolving the protein-targeted adsorbent. The resolved protein-targeted adsorbent is further used for adsorption.

[0029] As a further technical solution, in S3, the adsorption rate of the protein-targeted adsorbent is 4-6 BV / h.

[0030] As a further technical solution, in said S4, during the medium-pressure nanofiltration, the pressure is 0.3-0.6 MPa.

[0031] As a further technical solution, in the low-protein nanofiltration concentrate obtained in S4, the concentration of adenosylcobalamin is 1500-3000 mg / L, and the concentration of protein is 500-3000 mg / L.

[0032] As a further technical solution, in S5, during the conversion, the molar ratio of sodium cyanide to adenosylcobalamin in the low-protein nanofiltration concentrate is 1.5-2.5:1.

[0033] As a further technical solution, in S6, after adsorption by the adsorption column, the cyanide-containing supernatant produced by the adsorption and the cyanide-containing water obtained after washing are sequentially subjected to flash stripping and concentrated absorption to obtain a sodium cyanide solution with a mass concentration of 15-20%, which is continuously circulated for conversion in S5, and the remaining gas is absorbed by hydrated VOC.

[0034] As a further technical solution, in S6, during acetone decomposition, after acetone decomposition, the adsorption column is washed with water, and high-purity nitrogen is used to headspace the acetone to obtain gradient ketone wash water. The gradient ketone wash water is used as water for recycling in the water washing process after acetone decomposition. After three cycles, high-concentration ketone wash water with a volume concentration of ≥60% and low-concentration ketone wash water with a volume concentration of ≤20% are obtained. The high-concentration ketone wash water is evaporated to recover acetone or used as a mobile phase for chromatography in S7. The low-concentration ketone wash water is continuously recycled. The excess ketone wash water is flash stripped and concentrated to obtain high-concentration ketone wash water, which is then evaporated to recover acetone or used as a fluid for chromatography in S7. The remaining gas is absorbed by hydrated VOC.

[0035] The hydrated VOC absorption method is carried out according to the method disclosed in the application number CN201910767158.4 and the patent name "A process for treating VOCs by continuous adsorption and desorption in an aqueous phase."

[0036] The working principle and beneficial effects of the present invention are:

[0037] 1, in the present invention, the first filtrate that VB12 hydrolyzed solution obtains through plate and frame filtration passes through low pressure, lateral flow fine filter, protein targeted adsorption, medium pressure nanofiltration successively, in the nanofiltration concentrated solution obtained, the concentration of adenosylcobalamin is up to 2500-3000mg / L, and the concentration of protein is then low to 500-3000mg / L, and in the nanofiltration concentrated solution obtained in existing technology, adenosylcobalamin concentration then only has 800-1000mg / L, and the concentration of protein is up to 18000-20000mg / L, therefore, when the high adenosylcobalamin concentration that the present invention obtains, the nanofiltration concentrated solution of ultralow protein concentration are converted through sodium cyanide again, greatly reduce the consumption of sodium cyanide, the consumption of sodium cyanide is reduced to the 3-6% of existing technology, greatly reduce the processing difficulty of the cyanide-containing water after conversion.Meanwhile, VB12 hydrolyzed solution is shortened to within 30h from the 60h of existing technology from the time of filtration to conversion, and production cost is significantly reduced.

[0038] 2. In the present invention, low-pressure, side-flow fine filtration is adopted, and the angle between the inflow direction of the first filtrate and the outflow direction of the fine filtrate is 100°-150°. The flow rate of the first filtrate is small and it is not easy to clog the membrane. At the same time, the shear stress on the protein molecular chain is small, and the fine filtration effect is good.

[0039] 3. In the present invention, the conversion supernatant is adsorbed on an adsorption column to obtain a cyanide-containing permeate, the adsorption column is washed with water to obtain cyanide-containing water, and the volatility of HCN is utilized to sequentially subject the obtained cyanide-containing permeate and cyanide-containing water to flash stripping and concentration absorption to obtain recovered sodium cyanide, which is further used for conversion in S5, and the remaining gas is absorbed by hydrated VOC, thereby achieving no tail gas emission in the entire process and recycling of sodium cyanide.

[0040] 4. In the present invention, after washing with water, the adsorption column is further subjected to acetone decomposition to obtain a secondary decomposition concentrated solution. After decomposition is completed, the adsorption column is regenerated by washing with water and simultaneously using high-purity nitrogen to headspace the acetone to obtain a gradient acetone wash water. The gradient acetone wash water is recycled as water for the acetone decomposition process. After three cycles, a high-concentration acetone wash water with a volume concentration of ≥60% and a low-concentration acetone wash water with a volume concentration of ≤20% are obtained. The high-concentration acetone wash water is evaporated to recover acetone or used as a mobile phase for chromatography in S7. The low-concentration acetone wash water is subjected to flash stripping and enrichment absorption to obtain a high-concentration acetone wash water, which is further recycled. Excess acetone wash water is then evaporated to recover acetone or used as a mobile phase for chromatography in S7. The remaining gas is absorbed by hydrated VOCs, collected in a buffer tank, and recycled for flash stripping to replenish the gas supply. The entire process has low energy consumption, achieves zero tail gas emissions, and achieves the recycling of acetone. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Figure 1 The present invention is a process flow chart for obtaining a low-protein nanofiltration concentrate from a VB12 hydrolyzate;

[0043] Figure 2 The figure is a process flow chart of the present invention for obtaining pure VB12 from low-protein nanofiltration concentrate. DETAILED DESCRIPTION

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0045] Example 1

[0046] like Figure 1-2 As shown, a VB12 refining energy-saving and emission-reduction process includes the following steps:

[0047] S1, the VB12 hydrolyzate is subjected to plate and frame filtration. When the VB12 content in the hydrolyzate is lower than 2 mg / L, the filtration is completed to obtain the first filtrate and the first filter cake; the volume of the first filtrate is 600M 3 , where the concentration of VB12 is 100 mg / L;

[0048] S2, the first filtrate is subjected to low-pressure, side-flow tubular fine filtration at a pressure of 0.08 MPa, with the angle between the inflow direction of the first filtrate and the outflow direction of the fine filtrate being 100°, to obtain the fine filtrate, and the by-product turbid filtrate is returned to the plate and frame filtration;

[0049] S3, the refined filtrate was washed with a volume of 10M 3 The protein-targeted adsorbent adsorbs the protein impurities at an adsorption rate of 6 BV / h to obtain a high-definition solution for 10 hours; after the adsorption is completed, the protein-targeted adsorbent is heated and resolved with an alcohol analytical solution at a heating temperature of 45°C to obtain an analytical concentrated solution and an analytical diluted solution. The analytical concentrated solution is cold-precipitated to obtain a supernatant and a precipitate, and the precipitate is filtered to obtain a filtrate and a second filter cake, wherein the supernatant, the filtrate and the analytical diluted solution are combined into an alcohol analytical solution, which is further used for heating and resolving the protein-targeted adsorbent, and the analyzed protein-targeted adsorbent is further used for adsorption;

[0050] S4, the high-pressure nanofiltration of the high-definition liquid, the nanofiltration pressure is 0.6MPa, to obtain a nanofiltration concentrate, the nanofiltration concentrate is adsorbed by a protein-targeted adsorbent, and the concentration of adenosylcobalamin is 3000mg / L, the protein concentration is 900mg / L, and the volume is 19M 3 Low protein nanofiltration concentrate;

[0051] S5, adding sodium cyanide to the low-protein nanofiltration concentrate for conversion for 4 hours to obtain a conversion clear solution; during the conversion, the molar amount of sodium cyanide added is 1.5 times the molar amount of adenosylcobalamin in the low-protein nanofiltration concentrate;

[0052] S6, the conversion supernatant was washed with 3M 3The adsorption column is adsorbed for 6 hours with an adsorption rate of 1.5 BV / h to obtain a cyanide-containing permeate; the adsorption column is washed with water, and the obtained cyanide-containing water wash, the cyanide-containing permeate and the cyanide-containing water wash are sequentially subjected to flash stripping and concentration absorption to obtain a sodium cyanide solution with a mass concentration of 15%, which is further used for conversion in S5; after water washing, the adsorption column is analyzed with acetone to obtain a secondary refined concentrated solution; after the analysis is completed, the adsorption column needs to be regenerated, and the adsorption column is washed with water during regeneration, and high-purity nitrogen is used to headspace the acetone to obtain gradient ketone washing water, which is used as water for recycling in the acetone analysis process. After three cycles, high-concentration ketone washing water (volume concentration ≥ 60%) and low-concentration ketone washing water (volume concentration ≤ 20%) are obtained, and the high-concentration ketone washing water is evaporated to recover acetone or used as a mobile phase for chromatography in S7, and the low-concentration ketone washing water is continuously recycled. Excess ketone washing water (≤4000ppm) is subjected to flash stripping and concentration absorption to obtain high-concentration ketone washing water, which is then evaporated to recover acetone or used as liquidity for chromatography in S7. The remaining gas is absorbed by hydrated VOC, collected in a buffer tank, and recycled for flash stripping to achieve zero tail gas emissions.

[0053] S7. The purified concentrate from the second solution is concentrated by chromatography, evaporated and crystallized to obtain pure VB12.

[0054] Example 2

[0055] S1, the VB12 hydrolyzate is subjected to plate and frame filtration. When the VB12 content in the hydrolyzate is lower than 2 mg / L, the filtration is completed to obtain the first filtrate and the first filter cake; the volume of the first filtrate is 600M 3 , where the concentration of VB12 is 100 mg / L;

[0056] S2, the first filtrate is subjected to low-pressure, side-flow tubular fine filtration at a pressure of 0.1 MPa, with the angle between the inflow direction of the first filtrate and the outflow direction of the fine filtrate being 120°, to obtain the fine filtrate, and the by-product turbid filtrate is returned to the plate and frame filtration;

[0057] S3, the refined filtrate was washed with a volume of 10M 3 The protein-targeted adsorbent adsorbs the protein impurities at an adsorption rate of 5 BV / h to obtain a high-definition solution for 12 hours; after the adsorption is completed, the protein-targeted adsorbent is heated and resolved with an alcohol analytical solution at a heating temperature of 50°C to obtain an analytical concentrated solution and an analytical diluted solution. The analytical concentrated solution is cold-precipitated to obtain a supernatant and a precipitate, and the precipitate is filtered to obtain a filtrate and a second filter cake, wherein the supernatant, the filtrate and the analytical diluted solution are combined into an alcohol analytical solution, which is further used for heating and resolving the protein-targeted adsorbent, and the analyzed protein-targeted adsorbent is further used for adsorption;

[0058] S4, the high-pressure nanofiltration of the high-resolution liquid, the nanofiltration pressure is 0.5 MPa, to obtain a nanofiltration concentrate, the nanofiltration concentrate is adsorbed by a protein-targeted adsorbent, and the concentration of adenosylcobalamin is 2700 mg / L, the protein concentration is 1000 mg / L, and the volume is 21M 3 Low protein nanofiltration concentrate;

[0059] S5. Add sodium cyanide to the low-protein nanofiltration concentrate for conversion for 4 hours to obtain a conversion clear solution; during the conversion, the molar amount of sodium cyanide added is 2 times the molar amount of adenosylcobalamin in the low-protein nanofiltration concentrate;

[0060] S6, the conversion supernatant was washed with 3M 3 The adsorption column is adsorbed for 7 hours at an adsorption rate of 1.5 BV / h to obtain a cyanide-containing permeate; the adsorption column is washed with water, and the obtained cyanide-containing water wash, the cyanide-containing permeate and the cyanide-containing water wash are sequentially subjected to flash stripping and concentration absorption to obtain a sodium cyanide solution with a mass concentration of 18%, which is further used for conversion in S5; after water washing, the adsorption column is analyzed with acetone to obtain a secondary refined concentrated solution; after the analysis is completed, the acetone on the adsorption column needs to be analyzed, and the adsorption column is washed with water during regeneration, and high-purity nitrogen is used to headspace the acetone to obtain gradient ketone washing water, which is used as water for recycling in the acetone analysis process. After three cycles, high-concentration ketone washing water (volume concentration ≥ 60%) and low-concentration ketone washing water (volume concentration ≤ 20%) are obtained, and the high-concentration ketone washing water is evaporated to recover acetone or used as a mobile phase for chromatography in S7, and the low-concentration ketone washing water is continuously recycled. The excess ketone washing water (≥6000ppm) is subjected to two flash stripping and concentration absorption to obtain high-concentration ketone washing water, which is then evaporated to recover acetone or used as liquidity for chromatography in S7. The remaining gas is absorbed by hydrated VOC, collected in a buffer tank, and recycled for flash stripping to achieve zero tail gas emissions.

[0061] S7. The purified concentrate from the second solution is concentrated by chromatography, evaporated and crystallized to obtain pure VB12.

[0062] Example 3

[0063] S1, the VB12 hydrolyzate is subjected to plate and frame filtration. When the VB12 content in the hydrolyzate is lower than 2 mg / L, the filtration is completed to obtain the first filtrate and the first filter cake; the volume of the first filtrate is 600M 3 , where the concentration of VB12 is 100 mg / L;

[0064] S2, the first filtrate is subjected to low-pressure, side-flow tubular fine filtration at a pressure of 0.15 MPa, with the angle between the inflow direction of the first filtrate and the outflow direction of the fine filtrate being 150°, to obtain the fine filtrate, and the by-product turbid filtrate is returned to the plate and frame filtration;

[0065] S3, the refined filtrate was washed with a volume of 10M 3The protein-targeted adsorbent adsorbs the protein impurities at an adsorption rate of 6 BV / h to obtain a high-definition solution for 10 hours; after the adsorption is completed, the protein-targeted adsorbent is heated and resolved with an alcohol analytical solution at a heating temperature of 55° C. After resolution, a concentrated analytical solution and a diluted analytical solution are obtained, and the concentrated analytical solution is cold-precipitated to obtain a supernatant and a precipitate, and the precipitate is filtered to obtain a filtrate and a second filter cake, wherein the supernatant, the filtrate and the diluted analytical solution are combined into an alcohol analytical solution, which is further used for heating and resolving the protein-targeted adsorbent, and the protein-targeted adsorbent after resolution is further used for adsorption;

[0066] S4, the high-pressure nanofiltration of the high-resolution liquid, the nanofiltration pressure is 0.4 MPa, to obtain a nanofiltration concentrate, the nanofiltration concentrate is adsorbed by a protein-targeted adsorbent, and the concentration of adenosylcobalamin is 2400 mg / L, the protein concentration is 1200 mg / L, and the volume is 24M 3 Low protein nanofiltration concentrate;

[0067] S5, adding sodium cyanide to the low-protein nanofiltration concentrate for conversion for 4 hours to obtain a conversion clear solution; during the conversion, the molar amount of sodium cyanide added is 2.5 times the molar amount of adenosylcobalamin in the low-protein nanofiltration concentrate;

[0068] S6, the conversion supernatant was washed with 3M 3 The adsorption column is adsorbed for 8 hours with an adsorption rate of 1.5 BV / h to obtain a cyanide-containing permeate; the adsorption column is washed with water to obtain a cyanide-containing water wash, and the cyanide-containing permeate and the cyanide-containing water wash are sequentially subjected to flash stripping and concentration absorption to obtain a sodium cyanide solution with a mass concentration of 20%, which is further used for conversion in S5; after washing with water, the adsorption column is analyzed with acetone to obtain a secondary refined concentrated solution; after the analysis is completed, the adsorption column needs to be regenerated, and the adsorption column is washed with water during regeneration, and high-purity nitrogen is used to headspace the acetone to obtain a gradient ketone wash water, which is used as water for recycling in the acetone analysis process. After three cycles, high-concentration ketone wash water (volume concentration ≥40%) and low-concentration ketone wash water (volume concentration ≤20%) are obtained, and the high-concentration ketone wash water is evaporated to recover acetone or used as a mobile phase for chromatography in S7, and the low-concentration ketone wash water is continuously recycled. Excess ketone washing water (≤4000ppm) is subjected to flash stripping and concentration absorption to obtain high-concentration ketone washing water, which is then evaporated to recover acetone or used as liquidity for chromatography in S7. The remaining gas is absorbed by hydrated VOC, collected in a buffer tank, and recycled for flash stripping to achieve zero tail gas emissions.

[0069] S7. The purified concentrate from the second solution is concentrated by chromatography, evaporated and crystallized to obtain pure VB12.

[0070] Taking Example 1 as an example, the energy-saving and emission-reduction process based on VB12 extraction of the present invention has the following advantages compared with the existing process:

[0071]

[0072] From the comparison in the above table, it can be seen that compared with the existing process, before conversion, the process of Example 1 only uses 1 / 2 of the adsorbent dosage and 1 / 3 of the adsorption time, and obtains 1 / 3 of the volume of ammonia-free low-protein nanofiltration concentrate. During conversion, the amount of sodium cyanide used in the process of Example 1 is significantly reduced from 60-120 times the molar amount of adenosylcobalamin used in the existing process to 1.5 times. At the same time, only 1 / 2 of the adsorbent dosage and 1 / 2 of the adsorption time are used, especially the evaporation amount of acetone and water is only 1 / 12, and the process has zero emissions, is safe and environmentally friendly.

[0073] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A VB12 refining energy-saving and emission-reduction process, characterized in that: The following steps are involved: S1, Plate and frame filtration The VB12 hydrolyzate is subjected to plate-and-frame filtration to obtain a first filtrate; S2, low pressure, side flow fine filtration The first filtrate is subjected to low-pressure, side-flow tubular fine filtration to obtain a fine filtrate; S3. Protein targeted adsorption The semen filtrate is adsorbed by a protein-targeted adsorbent to obtain a high-definition liquid; S4, medium pressure nanofiltration and secondary protein removal The high-resolution solution is subjected to medium-pressure nanofiltration to obtain a nanofiltration concentrate; and protein impurities in the nanofiltration concentrate are adsorbed by a protein-targeted adsorbent to obtain a low-protein nanofiltration concentrate; S5. Conversion adding sodium cyanide to the low-protein nanofiltration concentrate for conversion to obtain a conversion clear solution; S6, adsorption column adsorption The converted supernatant was adsorbed on an adsorption column, washed with water and analyzed with acetone to obtain a secondary refined concentrated solution; S7, chromatography, concentration, evaporation and crystallization The purified concentrate from the second solution was concentrated by chromatography and evaporated for crystallization to obtain pure VB12. In S2, during low-pressure, side-flow fine filtration, the pressure is 0.08-0.15 MPa, and the angle between the inflow direction of the first filtrate and the outflow direction of the fine filtrate is 100°-150°; In the S4, during medium-pressure nanofiltration, the pressure is 0.4-0.6 MPa; In S6, after adsorption by the adsorption column, the cyanide-containing permeate produced by adsorption and the cyanide-containing water obtained after washing are sequentially subjected to flash stripping and concentrated absorption to obtain a sodium cyanide solution with a mass concentration of 15-20%, which is continuously circulated for conversion in S5, and the remaining gas is absorbed by hydrated VOC; In the S6, after acetone is resolved, the adsorption column is washed with water, and high-purity nitrogen is used to headspace the acetone to obtain gradient ketone wash water. The gradient ketone wash water is used as water for recycling in the water washing process after acetone resolution. After three cycles, high-concentration ketone wash water with a volume concentration of ≥60% and low-concentration ketone wash water with a volume concentration of ≤20% are obtained. The high-concentration ketone wash water is evaporated to recover acetone or used as a mobile phase for chromatography in S7. The low-concentration ketone wash water is continuously recycled. The excess ketone wash water is flash stripped and concentrated to obtain high-concentration ketone wash water, which is then evaporated to recover acetone or used as a mobile phase for chromatography in S7. The remaining gas is absorbed by hydrated VOC.

2. The energy-saving and emission-reduction process for refining VB12 according to claim 1, characterized in that: In the S3, after the protein-targeted adsorbent is adsorbed, the protein-targeted adsorbent is heated and decomposed with an alcohol solution at a heating temperature of 40-56° C. to obtain a decomposition concentrate and a decomposition dilute solution. The decomposition concentrate is cold-precipitated to obtain a supernatant and a precipitate. The precipitate is filtered to obtain a filtrate and a filter cake. The supernatant, the filtrate and the decomposition dilute solution are combined into an alcohol decomposition solution, which is further used for heating and decomposing the protein-targeted adsorbent. The decomposed protein-targeted adsorbent is further used for adsorption.

3. The energy-saving and emission-reduction process for refining VB12 according to claim 2, characterized in that: In the S3, the adsorption rate of the protein-targeted adsorbent is 4-6 BV / h.

4. The energy-saving and emission-reduction process for refining VB12 according to claim 1, characterized in that: In the S4, the low-protein nanofiltration concentrate obtained has a concentration of adenosylcobalamin of 1500-3000 mg / L and a protein concentration of 500-3000 mg / L.

5. The energy-saving and emission-reduction process for refining VB12 according to claim 1, characterized in that: In the S5, during the conversion, the molar ratio of sodium cyanide to adenosylcobalamin in the low-protein nanofiltration concentrate is 1.5-2.5:1.

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