A method for producing vitamin b12 using microchannel technology

Abstract

This invention provides a method for producing vitamin B12 using microchannel reaction technology. The method involves acidifying, hydrolyzing, filtering, and analyzing the vitamin B12 fermentation broth, followed by a cyanidation reaction in a microchannel reactor. Further filtration, analysis, and concentration yield vitamin B12. This method produces cyanide-treated vitamin B12 with a thorough conversion reaction and increased yield. It also reduces the amount of cyanide used, thus reducing pollution and costs. The equipment has good airtightness, and the small amount of hydrogen cyanide gas generated is completely recovered and centrally treated, greatly reducing harm to the environment and human health. This method is environmentally friendly and contributes to green production.

Description

Technical Field

[0001] This invention relates to a method for producing vitamin B12 using microchannel technology, belonging to the field of bio-fermentation. Background Technology

[0002] Vitamin B 12 Cobalamin (also known as cobalamin) is a water-soluble vitamin and the only vitamin containing a metal element. It is essential for maintaining the health of the nervous system, the formation of red blood cells, and DNA synthesis. It has important functions in promoting the normal function of the nervous system, supporting red blood cell production, and participating in DNA synthesis and repair. It is widely used in medicine, biology and other fields.

[0003]

[0004] Microchannel reaction technology is a continuous flow reaction technology with microreactors as the core component. This technology features efficient heat transfer, efficient mass transfer, and rapid reaction, and the reaction rate is controllable and the reaction scale can be flexibly adjusted. It has significant advantages in a variety of chemical synthesis applications, which can improve reaction yield and product purity, eliminate safety hazards, shorten reaction production cycle, reduce solvent use and waste generation, and achieve seamless integration from laboratory process development to industrial scale-up production. It is very suitable for chemical synthesis.

[0005] Wang Chi 【1】 Using continuous flow microreaction technology, a key intermediate of retrobacterium was synthesized, achieving a yield of 98% for target compound I. (Wu Yuejiang) 【2】 Isopropyl nitrate was synthesized using continuous flow microchannel technology, overcoming the problems of difficult reaction control, excessively high reaction temperature, and low yield associated with traditional processes. (Li Xiaoning) 【3】 The reaction of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate was enhanced using a microchannel continuous flow process. The selectivity of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate was 87.96%, and the yield was 62.97%. The continuous flow process avoids the disadvantages of traditional batch reactor processes, such as long reaction cycles and limited yield. (Niu Kexin) 【4】 A highly efficient liquid-liquid two-phase continuous flow chemical reaction device was constructed using a three-dimensional chip microreactor as its core. In this device, using tetrabutylammonium bromide (TBAB) as a catalyst and sodium hypochlorite as an oxidant, the phase-transfer catalytic oxidation reaction of benzyl alcohol to benzaldehyde was studied. The yield of benzaldehyde was 97.50%, significantly improving the reaction efficiency compared to a conventional microreactor. This demonstrates that the device can effectively increase the interphase area between the liquid and liquid phases and improve the mass transfer rate, showing significant advantages and broad potential applications in liquid-liquid two-phase reactions. (Zhang Xueting) 【5】High molecular weight polypropylene glycol (PPG) was prepared using microchannel reaction technology. After fully understanding the ROP mechanism of DMC catalyzing PO in MCR and its micro-mixing characteristics, the preparation of high molecular weight PPG was achieved.

[0006] Vitamin B12 is generally produced by microbial fermentation. After fermentation, the fermentation broth is hydrolyzed under acidic and heated conditions, the cell walls of the bacteria are broken, and vitamin B12 is released from the cells. It is then obtained through processes such as filtration, cyanidation, purification, concentration, crystallization, drying, mixing, and sieving.

[0007] In the production of vitamin B12, various forms of cobalamin (methylcobalamin, nitrosocbalamin, adenosylcobalamin, etc.) need to be converted into the more stable cyanocbalamin. This conversion reaction uses highly toxic sodium cyanide or less toxic potassium cyanide, sodium cyanide, or other cyanide-containing compounds, requiring heating to above 100°C. However, traditional production methods typically use reaction kettles, which have long reaction times, low conversion efficiency, numerous byproducts, and poor product quality. Furthermore, incomplete conversion leads to the release of highly toxic hydrogen cyanide gas from some cyanide-containing compounds upon heating, severely polluting the environment and harming human health. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a method for producing vitamin B12 using microchannel reaction technology, comprising the following steps: S1: Take vitamin B12 fermentation broth, acidify and hydrolyze it, filter it, and collect the filtrate; S2: Adjust the pH value of the filtrate from step S1, adsorb and elute it using a cation exchange resin, and collect the eluent A; S3: Add sodium nitrite to the concentrated eluent A from step S2, adjust the pH value, add a cyano compound, and then pump it into microchannel reactor a, collect the cyanide solution, and then further filter, eluate, and concentrate it to obtain vitamin B12.

[0009] Preferably, in step S1, the hydrolysis temperature is 70-100℃, the hydrolysis time is 10-30 min, and the pH is 3.0-6.0.

[0010] Preferably, in step S1, after acidification and hydrolysis, flocculant A is added. Flocculant A is one of aluminum chloride or polyaluminum ferric chloride, and the pH value is adjusted with 10-20% hydrochloric acid.

[0011] Further, in step S1, after adding flocculant A, plate and frame filtration is performed, and the filtrate is collected.

[0012] Preferably, in step S2, the pH of the filtrate from step S1 is adjusted with hydrochloric acid, and then adsorbed using a cation exchange resin. Preferably, in step S2, the elution process uses an aqueous ammonia solution as the eluent, with a concentration of 5-15%.

[0013] Preferably, in step S3, the concentration temperature is 40-80°C.

[0014] Preferably, in step S3, the amount of sodium nitrite added is 1-10 g / L.

[0015] Preferably, in step S3, the pH value is adjusted to 4-8 using 10-20% hydrochloric acid.

[0016] Preferably, in step S3, the cyanidation reaction temperature is 100-130℃, the feed rate is 0.1-1L / min, and the reaction time is 1-5min.

[0017] Preferably, in step S3, the amount of the cyano compound added is 0.6-1.2 times the amount of vitamin B12 in the eluent A.

[0018] Furthermore, in step S3, the cyano compound is selected from sodium cyanide, potassium cyanide, sodium cyanide, and cyanamide.

[0019] Further, after the eluent A reacts in a microchannel reactor, it is then filtered, eluented, and concentrated to obtain vitamin B12, including the following steps S4-S9, specifically:

[0020] S4: Add flocculant B to the cyanide solution in step S3, adjust the pH to neutral, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0021] S5: Adjust the pH of the cyanide filtrate from step S4, pump it into a macroporous adsorption resin for adsorption and elution to remove impurities, and collect the elution solution B.

[0022] S6: Concentrate the eluent B from step S5 to obtain the concentrate.

[0023] S7: After cooling the concentrate from step S6, pump it into anion exchange resin for adsorption and impurity removal, and collect the purified solution.

[0024] S8: After adjusting the pH of the purified solution from step S7 with glacial acetic acid, pump it into the chromatography resin for adsorption, development, and elution, and collect the elution solution C.

[0025] S9: Crystallize the solution C from step S8 to obtain wet vitamin B12 crystals, then centrifuge, dry, mix, and sieve to finally obtain vitamin B12.

[0026] Preferably, in step S4, flocculant B is a composite of polyaluminum chloride and polyaluminum ferric chloride, with a ratio of polyaluminum chloride:polyaluminum ferric chloride = 1:0.5-2.0; the pH is adjusted to neutral using 5-15% liquid alkali.

[0027] Preferably, in step S5, the pH of the cyanide filtrate is adjusted to 2-6 using 5-15% hydrochloric acid; the eluent is acetone.

[0028] Preferably, in step S6, the concentration temperature is 40-80℃.

[0029] Preferably, in step S7, the concentrate is cooled to 2-10°C.

[0030] Preferably, in step S8, the pH of the purified solution is adjusted to 3-7 using glacial acetic acid; the developing agent and the eluent are acetone.

[0031] Preferably, in step S9, the crystallization temperature is 5-30℃ and the crystallization time is 5-10h.

[0032] The production method for vitamin B12 provided by this invention reduces conversion time by 93.2%, cyanide usage by 62.8%, total impurities in the cyanide solution by 26.2%, and conversion yield by 7.7%. Furthermore, due to the excellent airtightness of the microreactor equipment, all hydrogen cyanide gas generated during the reaction is recovered and treated harmlessly, significantly reducing harm to the environment and human health. The reduction in cyanide usage not only helps lower production costs but, more importantly, greatly reduces the CN content in the product. - The equipment is well-sealed, and all the small amount of hydrogen cyanide gas produced is recovered and centrally treated, which greatly reduces the harm to the environment and human health, making it environmentally friendly and conducive to achieving green production. Attached Figure Description

[0033] Figure 1 An apparatus for producing vitamin B12 using microchannel reaction technology Detailed Implementation

[0034] The invention is illustrated below with examples. It should be understood that these examples are for illustrative purposes only and not for limiting the invention. The scope and core content of the invention are defined by the claims.

[0035] Example 1

[0036] S1: Take the vitamin B12 fermentation broth, adjust the pH value to 3.0 with 10% hydrochloric acid, hydrolyze at 70℃, acidify and hydrolyze for 10 minutes, add flocculant A - polyaluminum chloride, filter by plate and frame filter, and collect the filtrate.

[0037] S2: Adjust the pH of the filtrate from step S1 to 2.0 with 10% hydrochloric acid, adsorb it with a cation exchange resin, elute it with 5% ammonia water, and collect the eluent A.

[0038] S3: Concentrate the eluent from step S2 at 40°C, add 1 g / L sodium nitrite, adjust the pH to 4.0 with 10% hydrochloric acid, add 0.6 times the amount of sodium cyanide, and then pump it into microchannel reactor a, model AFR-G1 silicon carbide. Control the temperature at 100°C, the feed rate at 1 L / min, and the reaction time at 1 min to carry out the cyanidation reaction, and collect the cyanide liquid.

[0039] S4: Add flocculant B—polyaluminum chloride:polyaluminum ferric chloride = 1:0.5—to the cyanide solution in step S3, adjust the pH to neutral with 5% liquid alkali, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0040] S5: Adjust the pH of the cyanide filtrate from step S4 to 2.0 with 5% hydrochloric acid, pump it into a macroporous adsorption resin for adsorption, remove impurities by elution with acetone, and collect the eluent B.

[0041] S6: Concentrate the eluent B from step S5 at 40°C to obtain a concentrated solution.

[0042] S7: After cooling the concentrate from step S6 to 2°C, pump it into anion exchange resin for adsorption and impurity removal, and collect the purified solution.

[0043] S8: Adjust the pH of the purified solution from step S7 to 3.0 with glacial acetic acid, then pump it into the chromatography resin for adsorption. Spread the solution with acetone and elute it, then collect the eluent C.

[0044] S9: Crystallize the solution C from step S8 at 5°C for 5 hours to obtain wet vitamin B12 crystals. Then, centrifuge, dry, mix, and sieve to finally obtain vitamin B12.

[0045] Using this example to produce vitamin B12, the total impurities in the cyanide solution were found to be 15.3%, and the conversion rate was 98.7%.

[0046] Example 2

[0047] S1: Take the vitamin B12 fermentation broth, adjust the pH to 5.0 with 15% hydrochloric acid, hydrolyze at 80℃, acidify and hydrolyze for 20 minutes, add flocculant A - polyaluminum chloride, filter by plate and frame filter, and collect the filtrate.

[0048] S2: Adjust the pH of the filtrate from step S1 to 4.0 with 15% hydrochloric acid, adsorb it with a cation exchange resin, and elute it with 10% ammonia water, collecting the eluent A.

[0049] S3: Concentrate the eluent A from step S2 at 60℃, add 5g / L sodium nitrite, adjust the pH to 6.0 with 15% hydrochloric acid, add 1.2 times the amount of potassium ferrocyanide, and then pump it into microchannel reactor a. Control the temperature at 110℃, the feed rate at 0.5L / min, and the reaction time at 2min to carry out the cyanidation reaction, and collect the cyanide solution.

[0050] S4: Add flocculant B—polyaluminum chloride:polyaluminum ferric chloride = 1:1—to the cyanide solution in step S3, adjust the pH to neutral with 10% liquid alkali, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0051] S5: Adjust the pH of the cyanide filtrate from step S4 to 4.0 with 10% hydrochloric acid, pump it into a macroporous adsorption resin for adsorption, remove impurities by elution with acetone, and collect the eluent B.

[0052] S6: Concentrate the eluent B from step S5 at 60°C to obtain a concentrated solution.

[0053] S7: After cooling the concentrate from step S6 to 6°C, pump it into anion exchange resin for adsorption and impurity removal, and collect the purified solution.

[0054] S8: Adjust the pH of the purified solution from step S7 to 5.0 with glacial acetic acid, then pump it into the chromatography resin for adsorption. Spread the solution with acetone and elute it, then collect the eluent C.

[0055] S9: Crystallize the solution from step S8 at 10°C for 8 hours to obtain wet vitamin B12 crystals. Then, after centrifugation, drying, mixing, and sieving, vitamin B12 is finally obtained.

[0056] Using this example to produce vitamin B12, the total impurities in the cyanide solution were measured to be 13.1%, and the conversion rate was 97.1%.

[0057] Example 3

[0058] S1: Take the vitamin B12 fermentation broth, adjust the pH to 6.0 with 20% hydrochloric acid, hydrolyze at 100℃, acidify and hydrolyze for 30 minutes, add flocculant A - polyaluminum ferric chloride, filter by plate and frame filter, and collect the filtrate.

[0059] S2: Adjust the pH of the filtrate from step S1 to 5.0 with 20% hydrochloric acid, adsorb it with a cation exchange resin, and elute it with 15% ammonia water, collecting the eluent A.

[0060] S3: Concentrate the eluent A from step S2 at 80℃, add 10g / L sodium nitrite, adjust the pH to 8.0 with 20% hydrochloric acid, add 1.0 times the amount of monocyanamide, and then pump it into microchannel reactor a. Control the temperature at 130℃, the feed rate at 0.2L / min, and the reaction time at 5min to carry out the cyanidation reaction, and collect the cyanide solution.

[0061] S4: Add flocculant B—polyaluminum chloride:polyaluminum ferric chloride = 1:2—to the cyanide solution in step S3, adjust the pH to neutral with 15% liquid alkali, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0062] S5: Adjust the pH of the cyanide filtrate from step S4 to 6.0 with 15% hydrochloric acid, pump it into a macroporous adsorption resin for adsorption, and remove impurities by elution with acetone, collecting the eluent B.

[0063] S6: Concentrate the eluent B from step S5 at 80°C to obtain a concentrated solution.

[0064] S7: After cooling the concentrate from step S6 to 10°C, pump in anion exchange resin to adsorb impurities and collect the purified solution.

[0065] S8: Adjust the pH of the purified solution from step S7 to 7.0 with glacial acetic acid, then pump it into the chromatography resin for adsorption. Spread the solution with acetone and elute it, then collect the eluent C.

[0066] S9: Crystallize the solution C from step S8 at 30℃ for 10 hours to obtain wet vitamin B12 crystals, then centrifuge, dry, mix, and sieve to finally obtain vitamin B12.

[0067] Using this example to produce vitamin B12, the total impurities in the cyanide solution were measured to be 13.8%, and the conversion rate was 98.2%.

[0068] Comparative Example 1

[0069] S1: Take the vitamin B12 fermentation broth, adjust the pH value to 3.0 with 10% hydrochloric acid, hydrolyze at 70℃, acidify and hydrolyze for 10 minutes, add flocculant A - polyaluminum chloride, filter by plate and frame filter, and collect the filtrate.

[0070] S2: Adjust the pH of the filtrate from step S1 to 2.0 with 10% hydrochloric acid, adsorb it with a cation exchange resin, elute it with 5% ammonia water, and collect the eluent A.

[0071] S3: Concentrate the eluent A from step S2 at 40℃, add 1g / L sodium nitrite, adjust the pH to 4.0 with 10% hydrochloric acid, then add 2.0 times the amount of sodium cyanide. In the reaction vessel, control the temperature at 100℃ and the reaction time at 30min to carry out the cyanidation reaction, and collect the cyanide solution.

[0072] S4: Add flocculant B—polyaluminum chloride:polyaluminum ferric chloride = 1:0.5—to the cyanide solution in step S3, adjust the pH to neutral with 5% liquid alkali, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0073] S5: Adjust the pH of the cyanide filtrate from step S4 to 2.0 with 5% hydrochloric acid, pump it into a macroporous adsorption resin for adsorption, remove impurities by elution with acetone, and collect the eluent B.

[0074] S6: Concentrate the eluent B from step S5 at 40°C to obtain a concentrated solution.

[0075] S7: After cooling the concentrate from step S6 to 2°C, pump it into anion exchange resin for adsorption and impurity removal, and collect the purified solution.

[0076] S8: Adjust the pH of the purified solution from step S7 to 3.0 with glacial acetic acid, then pump it into the chromatography resin for adsorption. Spread the solution with acetone and elute it, then collect the eluent C.

[0077] S9: Crystallize the solution C from step S8 at 5°C for 5 hours to obtain wet vitamin B12 crystals. Then, centrifuge, dry, mix, and sieve to finally obtain vitamin B12.

[0078] Using this example to produce vitamin B12, the total impurities in the cyanide solution were found to be 18.4%, and the conversion rate was 91.4%.

[0079] Comparative Example 2

[0080] S1: Take the vitamin B12 fermentation broth, adjust the pH to 5.0 with 15% hydrochloric acid, hydrolyze at 90℃, acidify and hydrolyze for 20 minutes, add flocculant A - polyaluminum chloride, filter by plate and frame filter, and collect the filtrate.

[0081] S2: Adjust the pH of the filtrate from step S1 to 3.5 with 15% hydrochloric acid, adsorb it with a cation exchange resin, and elute it with 10% ammonia water, collecting the eluent A.

[0082] S3: Concentrate the eluent A from step S2 at 60℃, add 5g / L sodium nitrite, adjust the pH to 6.0 with 15% hydrochloric acid, then add 2.5 times the amount of sodium cyanide. In the reactor, control the temperature at 120℃ and the reaction time at 40min to carry out the cyanidation reaction, and collect the cyanide solution.

[0083] S4: Add flocculant B—polyaluminum chloride:polyaluminum ferric chloride = 1:1—to the cyanide solution in step S3, adjust the pH to neutral with 10% liquid alkali, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0084] S5: Adjust the pH of the cyanide filtrate from step S4 to 4.0 with 10% hydrochloric acid, pump it into a macroporous adsorption resin for adsorption, remove impurities by elution with acetone, and collect the eluent B.

[0085] S6: Concentrate the eluent B from step S5 at 60°C to obtain a concentrated solution.

[0086] S7: After cooling the concentrate from step S6 to 6°C, pump it into anion exchange resin for adsorption and impurity removal, and collect the purified solution.

[0087] S8: Adjust the pH of the purified solution from step S7 to 5.0 with glacial acetic acid, then pump it into the chromatography resin for adsorption. Spread the solution with acetone and elute it, then collect the eluent C.

[0088] S9: Crystallize the solution from step S8 at 15°C for 8 hours to obtain wet vitamin B12 crystals. Then, after centrifugation, drying, mixing, and sieving, vitamin B12 is finally obtained.

[0089] Using this example to produce vitamin B12, the total impurities in the cyanide solution were measured to be 19.1%, and the conversion rate was 89.8%.

[0090] Comparative Example 3

[0091] S1: Take the vitamin B12 fermentation broth, adjust the pH to 6.0 with 20% hydrochloric acid, hydrolyze at 100℃, acidify and hydrolyze for 30 minutes, add flocculant A - polyaluminum ferric chloride, filter by plate and frame filter, and collect the filtrate.

[0092] S2: Adjust the pH of the filtrate from step S1 to 5.0 with 20% hydrochloric acid, adsorb it with a cation exchange resin, and elute it with 155% ammonia water, collecting the eluent A.

[0093] S3: Concentrate the eluent A from step S2 at 80℃, add 10g / L sodium nitrite, adjust the pH to 8.0 with 20% hydrochloric acid, then add 3.0 times the amount of sodium cyanide. In the reactor, control the temperature at 130℃ and the reaction time at 50min to carry out the cyanidation reaction, and collect the cyanide solution.

[0094] S4: Add flocculant B—polyaluminum chloride:polyaluminum ferric chloride = 1:2—to the cyanide solution in step S3, adjust the pH to neutral with 15% liquid alkali, filter by plate and frame filter, collect the filtrate, and obtain cyanide filtrate.

[0095] S5: Adjust the pH of the cyanide filtrate from step S4 to 6.0 with 15% hydrochloric acid, pump it into a macroporous adsorption resin for adsorption, and remove impurities by elution with acetone, collecting the eluent B.

[0096] S6: Concentrate the eluent B from step S5 at 80°C to obtain a concentrated solution.

[0097] S7: After cooling the concentrate from step S6 to 10°C, pump in anion exchange resin to adsorb impurities and collect the purified solution.

[0098] S8: Adjust the pH of the purified solution from step S7 to 7.0 with glacial acetic acid, then pump it into the chromatography resin for adsorption. Spread the solution with acetone and elute it, then collect the eluent C.

[0099] S9: Crystallize the solution C from step S8 at 30℃ for 10 hours to obtain wet vitamin B12 crystals, then centrifuge, dry, mix, and sieve to finally obtain vitamin B12.

[0100] Using this example to produce vitamin B12, the total impurities in the cyanide solution were found to be 19.7%, and the conversion rate was 90.3%.

[0101] Table 1 Comparison of Vitamin B12 Conversion Rates between Examples and Comparative Examples

[0102]

[0103] As shown in Table 1, the production method provided by the present invention reduces the conversion time by 93.2%, the amount of cyanide used by 62.8%, the total impurities in the cyanide solution by 26.2%, and the conversion yield by 7.7%.

[0104] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications are also within the protection scope of the claims of the present invention.

Claims

1. A method for producing vitamin B12, characterized in that, Vitamin B12 is produced using microchannel technology.

2. The method for producing vitamin B12 according to claim 1, characterized in that, Specifically, the following steps are included: S1: Take the vitamin B12 fermentation broth, acidify and hydrolyze it, filter it, and collect the filtrate; S2: Adjust the pH of the filtrate from step S1, adsorb and desorb it using a cation exchange resin, and collect the desorbate A; S3: Sodium nitrite is added to the concentrated solution A from step S2, the pH is adjusted, a cyano compound is added, and then the solution is pumped into microchannel reactor a. The cyanide solution is collected, and then further filtered, analyzed, and concentrated to obtain vitamin B12.

3. The method for producing vitamin B12 according to claim 2, characterized in that: In step S1, the hydrolysis temperature is 70-100℃, the hydrolysis time is 10-30 min, and the pH is 3.0-6.

0.

4. The method for producing vitamin B12 according to claim 2, characterized in that: In step S1, after acidification and hydrolysis, flocculant A is added, which is either aluminum chloride or polyaluminum ferric chloride.

5. The method for producing vitamin B12 according to claim 2, characterized in that: In step S2, the analysis process uses an ammonia solution as the analysis agent, with a concentration of 5-15%.

6. The method for producing vitamin B12 according to claim 2, characterized in that: In step S3, the concentration temperature is 40-80℃.

7. The method for producing vitamin B12 according to claim 2, characterized in that: In step S3, the amount of sodium nitrite added is 1-10 g / L.

8. The method for producing vitamin B12 according to claim 2, characterized in that: In step S3, the pH value is adjusted to 4-8 using 10-20% hydrochloric acid.

9. The method for producing vitamin B12 according to claim 2, characterized in that: In step S3, the cyanidation reaction temperature is 100-130℃, the feed rate is 0.1-1L / min, and the reaction time is 1-5min.

10. The method for producing vitamin B12 according to claim 2, characterized in that: In step S3, the amount of the cyano compound added is 0.6-1.2 times the amount of vitamin B12 in the eluent A.

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