A double-cone separation and intensified extraction system and method for vitamin B2 fermentation liquor

Abstract

The application belongs to the technical field of biological extraction, and particularly relates to a double-cone separation intensified extraction system and method for vitamin B2 fermentation liquor, which comprises the following steps: detecting the solid content, titer and viscosity of the vitamin B2 fermentation liquor, and dividing the fermentation liquor into low-solid type, medium-solid type or high-solid type; setting a corresponding feeding speed according to the type of the fermentation liquor; feeding at different rotating speeds in the feeding stage of the double-cone separation; adopting a gradient pH control mode in the double-cone separation process; performing the first residue discharge-washing-second residue discharge process on the residue discharge, and the washing liquid dosage is 10%-20% of the volume of the fermentation liquor. Through the synergistic optimization of process parameters, the extraction yield and product purity of vitamin B2 are significantly improved without large-scale modification of the equipment, and the adaptability of the process to different batches of fermentation liquor is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of bio-extraction technology, specifically relating to a dual-cone separation enhanced extraction system and method for vitamin B2 fermentation broth. Background Technology

[0002] Vitamin B2 (riboflavin) is an essential vitamin for animal metabolism and is widely used in medicine, food additives, and feed additives. Currently, the microbial fermentation method is widely used to produce vitamin B2. The industrial fermentation is generally a two-stage fermentation, and the fermentation broth is separated, extracted, and purified to obtain the finished product.

[0003] The fermentation broth for vitamin B2 produced by microbial fermentation is complex, containing a large number of impurities such as bacteria, proteins, and polysaccharides, posing a significant challenge to separation and extraction. The double-cone centrifuge (double-cone cylinder centrifuge) combines the high dryness of the residue from a horizontal screw centrifuge with the clear liquid separation of a disc centrifuge, and is finding increasingly widespread application in the field of solid-liquid separation of fermentation broths.

[0004] However, the existing process for separating and extracting vitamin B2 using a double cone mill has the following technical problems: (1) The extraction yield of vitamin B2 under the existing process has not reached the advanced level in the industry, and some target products are lost with impurities. The traditional acid dissolution process is long and energy-intensive, and the purity of one dissolution, separation and crystallization is only 60%-70%. Although some existing improved methods can increase the yield to 85%-87%, there are still problems such as complex process and use of a large number of chemicals.

[0005] (2) Trace impurities in the fermentation broth are difficult to completely remove using existing double-cone separation processes, affecting product quality. In existing technologies, the use of disc centrifuges to separate fermentation broth is not very effective and results in low purity.

[0006] (3) In the face of fluctuations in the composition of different batches of fermentation broth (such as differences in cell content, protein content, vitamin B2 potency, etc.), the existing double cone separation process is prone to deviation in separation effect and lacks effective process adjustment means.

[0007] Therefore, improvements are urgently needed. Summary of the Invention

[0008] This invention addresses the technical problems of low yield, unstable purity, and poor process adaptability in existing vitamin B2 fermentation broth double-cone separation extraction processes by providing a vitamin B2 fermentation broth enhanced extraction system and method. The method of this invention significantly improves the extraction yield and product purity of vitamin B2 and enhances the process's adaptability to fluctuations in fermentation broth from different batches through the synergistic combination of fermentation broth characteristic prediction, staged rate-controlled separation, gradient pH regulation, and dynamic slag discharge control.

[0009] To achieve the above objectives, the present invention is implemented according to the following technical solution: A method for enhanced extraction of vitamin B2 from fermentation broth using a two-cone fractionation technique includes the following steps: S1. Samples of the vitamin B2 fermentation broth to be separated were taken and tested. The following indicators were determined: (1) solid content of the fermentation broth (i.e., the mass percentage of cells and insoluble impurities); (2) vitamin B2 potency (content) in the fermentation broth; (3) viscosity of the fermentation broth. Based on the test results of the above three indicators, the fermentation broth was classified into the following types: 1) Low-solids fermentation broth: solids content ≤8% and viscosity ≤50 mPa·s; 2) Medium-solid fermentation broth: solid content > 8% and ≤ 15%, or viscosity > 50 mPa·s and ≤ 100 mPa·s; 3) High-solids fermentation broth: solids content > 15%, or viscosity > 100 mPa·s.

[0010] S2. Based on the fermentation broth type determined in step S1, set the feed rate for entering the double-cone separation process: For low-solids fermentation broth, a rapid feeding mode is adopted, with the flow rate controlled at 2.0-2.5 m³ / h. 3 / h; For medium-solid fermentation broth, a medium-speed feed mode is adopted, with the flow rate controlled at 1.2-1.8 m³ / s. 3 / h; For high-solids fermentation broth, a slow feeding mode is adopted, with the flow rate controlled at 0.6-1.0 m³ / s. 3 / h.

[0011] The principle for determining the feed rate is: the higher the solid content and viscosity of the fermentation liquid, the lower the feed rate, so as to ensure sufficient settling and separation time in the drum of the double cone centrifuge.

[0012] S3. During the dual-cone separation process, the rotation speed should be adjusted as follows: (1) Feeding stage: The double cone centrifuge operates at the first speed, which is 60%-75% of the rated speed, preferably 68%-72% of the rated speed, and lasts for a period of time from the start of feeding until the feeding amount reaches 70%-80% of the total feeding amount; (2) Separation enhancement stage: When the feed amount reaches 70%-80% of the total feed amount, the speed of the double cone centrifuge is increased to the second speed, which is 85%-100% of the rated speed, preferably 90%-95% of the rated speed, and continues until the feeding is completed; (3) Slag discharge stage: After the feeding is completed, adjust the speed of the double cone centrifuge to the third speed, which is 40%-55% of the rated speed, preferably 45%-50% of the rated speed. After running for 2-5 minutes, perform the slag discharge operation.

[0013] The rated speed mentioned above is the maximum operating speed designed for the double cone centrifuge.

[0014] S4. During the double-cone separation process, add the extraction solution, which is either a nitric acid solution or a hydrochloric acid solution, into the double-cone centrifuge; the extraction solution is added using a gradient pH control method. (1) First stage: During the first 1 / 3 of the time after feeding begins, control the pH value of the material in the double cone centrifuge to 6.0-7.0; (2) Second stage: During the middle 1 / 3 of the time after the start of feeding, the pH value is gradually reduced to 4.5-5.5; (3) Third stage: In the last 1 / 3 of the time after the start of feeding until the end of separation, the pH value is further adjusted to 3.5-4.5.

[0015] Gradient pH control is achieved by adding different concentrations of extract to the double-cone centrifuge in stages, or by adding pH adjusters online.

[0016] S5. After separation, perform slag removal operation, which shall be carried out according to the following procedure: (1) First slag discharge: After running at the third speed for 2-5 minutes, the first slag discharge is carried out to discharge the solid slag material that has settled in the drum of the double cone centrifuge; (2) Washing: After the first slag discharge, a washing solution (preferably an acidic nitric acid solution or water with a pH of 3.5-4.5) is introduced into the double cone centrifuge. The amount of washing solution is 10%-20% of the fermentation liquid volume. The centrifuge is run at the third speed for 3-8 minutes. (3) Secondary slag discharge: After washing, secondary slag discharge is carried out to remove the remaining solid slag; (4) Collection: Collect the liquid phase discharged during the first and second slag discharge processes as the vitamin B2 extract; perform subsequent crystallization and drying treatment on the vitamin B2 extract to obtain the vitamin B2 product.

[0017] The present invention also proposes a vitamin B2 fermentation broth double cone separation enhanced extraction system, which is applied to the above-mentioned vitamin B2 fermentation broth double cone separation enhanced extraction method, including a double cone centrifuge, which is used to perform solid-liquid separation on the material therein.

[0018] The beneficial effects of this invention are: (1) By matching the type of fermentation liquid with the feed rate, speed gradient control, gradient pH control and dynamic slag discharge washing, the extraction yield of vitamin B2 can be increased by 3%-8% compared with the existing single process, reaching more than 90%.

[0019] (2) The present invention adopts gradient pH control combined with dynamic slag discharge washing, which effectively reduces the entrainment of impurities (bacterial cells, proteins, polysaccharides, etc.) in the extract, and the product purity can reach more than 98%.

[0020] (3) By predicting and classifying the characteristics of the fermentation broth, the present invention enables the double cone separation process to adapt to the component fluctuations of different batches of fermentation broth, thus avoiding the problem of unstable separation effect caused by the traditional "one-pot" operation method.

[0021] (4) By controlling the feeding speed and adjusting the speed gradient, this invention avoids the energy waste caused by long-term full-load operation of the double cone centrifuge, and the energy consumption per unit product can be reduced by more than 5%. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention. Detailed Implementation

[0024] The present invention will now be clearly described with reference to specific embodiments. These descriptions are merely illustrative and are not intended to limit the scope of the invention. Any modifications, equivalent substitutions, or improvements made by those skilled in the art based on the embodiments of the present invention without inventive effort to obtain all other embodiments should be included within the scope of protection of the present invention.

[0025] Example 1 like Figure 1 As shown, this embodiment uses a batch of vitamin B2 fermentation broth (solid content 10.5%, viscosity 65 mPa·s, vitamin B2 potency 12.5 g / L, belonging to medium-solid fermentation broth) as the treatment object, and performs double-cone separation extraction using the method of the present invention.

[0026] (1) Prediction of fermentation broth characteristics: Sampling and testing showed a solid content of 10.5% and a viscosity of 65 mPa·s, which determined it to be a medium-solid fermentation broth.

[0027] (2) Feeding speed control: A medium-speed feeding mode is adopted, and the feeding speed is controlled at 1.5 m. 3 / h, total feed rate is 3.0m 3 .

[0028] (3) Speed ​​gradient control: The rated speed of the double cone mill is 4000 rpm. During the feeding stage, it operates at a first speed of 2800 rpm (70% of the rated speed) until the feed rate reaches 2.4 m. 3 (80% of the total feed); then increase to the second speed of 3600 rpm (90% of the rated speed) and continue until feeding is complete; after feeding is complete, adjust to the third speed of 1800 rpm (45% of the rated speed), run for 3 minutes and then discharge slag.

[0029] (4) Gradient pH control: Prepare a 1.0% nitric acid solution as the extraction solution. Control the pH value to 6.5 for the first 20 minutes after the start of feeding; gradually lower the pH value to 5.0 for the middle 20 minutes; and lower the pH value to 4.0 for the last 20 minutes until the end of separation.

[0030] (5) Dynamic slag discharge and washing: After running at the third rotation speed of 1800 rpm for 3 minutes, the first slag discharge was performed; after the first slag discharge, 0.45 m of nitric acid washing solution with pH 4.0 was introduced. 3 (15% of the fermentation liquid volume), run at the third rotation speed for 5 minutes; then discharge the residue twice; collect the liquid phase from the two discharges.

[0031] (6) Post-processing: The collected extract is crystallized and dried.

[0032] The extraction yield of vitamin B2 in this embodiment was 91.2%, and the product purity was 98.5%.

[0033] Example 2 This embodiment uses a batch of high-solids vitamin B2 fermentation broth (solids content 18%, viscosity 120 mPa·s, vitamin B2 potency 11.0 g / L) as the treatment object.

[0034] (1) Prediction of fermentation broth characteristics: solid content 18%, viscosity 120 mPa·s, judged as high solid fermentation broth.

[0035] (2) Pre-dilution treatment: Add 0.8 times the volume of pH 4.5 nitric acid diluent to the fermentation broth. After dilution, the solid content is reduced to about 10%.

[0036] (3) Feeding speed control: Slow feeding mode is adopted, and the feeding speed is controlled at 0.8 m. 3 / h.

[0037] (4) Speed ​​gradient control: The rated speed of the double cone mill is 4000 rpm. During the feeding stage, the mill runs at the first speed of 2800 rpm until the feed rate reaches 75% of the total feed rate; then the speed is increased to the second speed of 3800 rpm (95% of the rated speed) and continues until the feeding is completed; after the feeding is completed, the speed is adjusted to the third speed of 2000 rpm (50% of the rated speed), and the slag is discharged after running for 4 minutes.

[0038] (5) Gradient pH control and dynamic slag discharge washing: Same as Example 1.

[0039] The extraction yield of vitamin B2 in this embodiment was 90.5%, and the product purity was 98.2%.

[0040] Comparative Example Using a vitamin B2 fermentation broth (medium-solid type) from the same source as a control, a traditional double-cone separation process (single feed rate 1.5 m) was employed. 3 The process involves a single rotation speed of 3500 rpm, a single pH of 5.0, and no washing steps.

[0041] The extraction yield of vitamin B2 was 84.7%, and the product purity was 96.8%.

[0042] The comparison shows that the extraction yield of the method of the present invention is increased by 6.5 percentage points and the product purity is increased by 1.7 percentage points compared with the traditional process.

[0043] The embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for enhanced extraction of vitamin B2 from fermentation broth using a double-cone separation technique, characterized in that: Includes the following steps: S1. Take samples of the vitamin B2 fermentation broth to be separated and test it to determine the solid content, vitamin B2 potency and viscosity. Based on the test results, classify the fermentation broth into low-solids, medium-solids or high-solids types. S2. Based on the fermentation broth type determined in step S1, set the feeding speed for entering the double cone separation process: use a fast feeding mode for low solids, a medium feeding mode for medium solids, and a slow feeding mode for high solids. S3. During the dual-cone separation process, the feeding stage operates at 60%-75% of the rated speed. After the feeding amount reaches 70%-80% of the total feeding amount, the speed is increased to 85%-100% of the rated speed until feeding is completed. After feeding is completed, the speed is reduced to 40%-55% of the rated speed. S4. During the double cone separation process, add the extraction solution and use a gradient pH control method; S5. After the double cone separation is completed, the residue is discharged. The residue discharge process is carried out by first residue discharge - washing - second residue discharge. After washing, the liquid phase is collected as the extract containing vitamin B2.

2. The vitamin B2 fermentation broth double-cone separation enhanced extraction method according to claim 1, characterized in that: In step S1, the solid content of the low-solids fermentation broth is ≤8% and the viscosity is ≤50 mPa·s, the solid content of the medium-solids fermentation broth is >8% and ≤15% or the viscosity is >50 mPa·s and ≤100 mPa·s, and the solid content of the high-solids fermentation broth is >15% or the viscosity is >100 mPa·s.

3. The method for enhanced extraction of vitamin B2 fermentation broth using a double-cone separation technique according to claim 1, characterized in that: In step S2, the flow rate in the rapid feeding mode is 2.0-2.5 m³ / s. 3 The flow rate in medium-speed feeding mode is 1.2-1.8 m³ / h. 3 / h, the flow rate in slow feed mode is 0.6-1.0 m³ / h. 3 / h.

4. The method for enhanced extraction of vitamin B2 fermentation broth using a double-cone separation technique according to claim 3, characterized in that: In step S3, the feeding stage operates at 68%-72% of the rated speed. After the feeding amount reaches 70%-80% of the total feeding amount, the speed is increased to 90%-95% of the rated speed until feeding is completed. After feeding is completed, the speed is reduced to 45%-50% of the rated speed.

5. The method for enhanced extraction of vitamin B2 fermentation broth using a double-cone separation technique according to claim 1, characterized in that: The extract in step S4 is a nitric acid solution or a hydrochloric acid solution with a concentration of 0.5%-2.0%.

6. The method for enhanced extraction of vitamin B2 fermentation broth using a double-cone separation technique according to claim 1, characterized in that: In step S4, the gradient pH control method is as follows: the pH value is controlled at 6.0-7.0 for the first 1 / 3 of the time after the start of feeding, the pH value is gradually lowered to 4.5-5.5 for the middle 1 / 3 of the time, and the pH value is lowered to 3.5-4.5 for the last 1 / 3 of the time until the end of separation.

7. The method for enhanced extraction of vitamin B2 fermentation broth using a double-cone separation technique according to claim 1, characterized in that: In step S5, the washing solution is an acidic solution with a pH of 3.5-4.5 or water, and the temperature is 30-50℃.

8. The method for enhanced extraction of vitamin B2 fermentation broth using a double-cone separation technique according to claim 7, characterized in that: The washing liquid should be 10%-20% of the fermentation liquid volume, and the washing time should be 3-8 minutes.

9. A vitamin B2 fermentation broth dual-cone separation enhanced extraction system, applied to the vitamin B2 fermentation broth dual-cone separation enhanced extraction method according to any one of claims 1-8, characterized in that: This includes double cone centrifuges, which are used for solid-liquid separation of materials.

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