A method for separating and extracting sodium pyruvate from a conversion solution produced by enzymatic production of sodium pyruvate

Abstract

The application discloses a method for separating and extracting sodium pyruvate from enzyme conversion liquid for producing sodium pyruvate, which uses enzyme conversion liquid containing sodium pyruvate produced by catalyzing lactic acid with lactic acid oxidase as raw material, removes bacteria bodies, concentrates, sprays, dries and extracts the enzyme conversion liquid with an organic solvent, and comprises the following steps: 1) removing bacteria bodies by filtering the enzyme conversion liquid containing sodium pyruvate through a ceramic membrane; 2) adding activated carbon to perform decolorization treatment; 3) performing concentration by vacuum distillation, so that the content of sodium pyruvate in the enzyme conversion liquid is concentrated to 500-700 g / L; 4) performing spray drying; 5) adding an organic solvent, performing heating, stirring and reflux extraction, cooling to room temperature, centrifugation and drying, and thus pure sodium pyruvate is obtained. The method is simple in operation, low in organic solvent consumption and capable of completely recovering the organic solvent, the produced sodium pyruvate is white in color, the content of the sodium pyruvate is more than 99.6%, the one-time yield is about 96%, the method is low in energy consumption, high in yield and high in product purity, and can be large-scale industrialized production.

Description

Technical Field

[0001] This invention relates to a method for separating and extracting sodium pyruvate from the conversion solution of sodium pyruvate produced by enzymatic process, belonging to the field of separation and purification. Background Technology

[0002] Sodium pyruvate is the sodium salt of pyruvic acid. Pyruvic acid is a three-carbon keto acid, a colorless liquid with an odor similar to acetic acid. It is an important intermediate metabolite in carbohydrate metabolism and a precursor to many useful compounds. Therefore, it has wide applications in chemical, pharmaceutical, and agrochemical industries, as well as in scientific research.

[0003] Currently, the conventional methods for separating and extracting sodium pyruvate mainly include vacuum distillation, ion exchange, and organic solvent extraction. Vacuum distillation is a common method in the chemical synthesis of pyruvate. However, for fermentation broth systems with complex compositions and low pyruvate content, this method is difficult to operate, energy-intensive, and inefficient. Ion exchange utilizes the different exchange or adsorption capacities of pyruvate and other substances on ion exchange resins, using ion exchange resin columns to separate pyruvate from other substances. Although ion exchange technology has excellent separation selectivity and high concentration factor, is easy to operate, has outstanding effects, and low extraction cost, the current yield and purity are not yet satisfactory, and it needs to be combined with other purification methods to obtain better results. Organic solvent extraction utilizes the different partition coefficients of pyruvate and other substances in organic solvents. By adding a specific organic solvent to the fermentation broth, pyruvate and other substances are separated. The organic solvents used in this method are typically diethyl ether or various esters, and the process is relatively simple. However, due to the large-scale use of organic solvents, high requirements are placed on solvent selectivity and regeneration capabilities. Furthermore, the use of these toxic, explosive, and volatile solvents causes serious environmental pollution and operational inconvenience. At the same time, organic solvents are expensive, and their volatility significantly increases the cost of industrial operation. Summary of the Invention

[0004] To address the aforementioned technical problems in existing technologies, the present invention aims to provide a method for separating and extracting sodium pyruvate from the conversion solution of enzymatic production of sodium pyruvate. The method of the present invention increases the concentration of sodium pyruvate and reduces the salt concentration through enzymatic conversion, followed by sterilization, concentration, spray drying, and organic solvent extraction.

[0005] The technical solution adopted in this invention is as follows:

[0006] A method for separating and extracting sodium pyruvate from the conversion solution of enzymatic production of sodium pyruvate, using an enzyme conversion solution containing sodium pyruvate obtained by lactate oxidase catalyzing lactic acid to produce sodium pyruvate as raw material, and subjecting the enzyme conversion solution to sterilization, concentration, spray drying, and organic solvent extraction, including the following steps:

[0007] 1) The enzyme conversion solution containing sodium pyruvate was filtered through a ceramic membrane to remove the bacterial cells;

[0008] 2) Add activated carbon to the filtrate from step 1) for decolorization;

[0009] 3) Then, the concentration was carried out by vacuum distillation to concentrate the sodium pyruvate content in the enzyme conversion solution to 500-700 g / L;

[0010] 4) Spray drying;

[0011] 5) Add organic solvent to the spray-dried product, heat and stir under reflux for extraction, cool to room temperature, centrifuge to remove organic solvent, and dry to obtain pure sodium pyruvate.

[0012] Furthermore, in step 3), the temperature of vacuum distillation is 55-70℃, so that the sodium pyruvate content in the enzyme conversion solution is concentrated to (600±20) g / L.

[0013] Further, the organic solvent mentioned in step 5) is one or a mixture of methanol, ethanol or acetone.

[0014] Furthermore, in step 5), the weight ratio of sodium pyruvate to organic solvent in the spray-dried product is 1:2 to 5.

[0015] Furthermore, in step 5), the heating and stirring reflux temperature is 40-80℃, the stirring time is 0.8-2 hours, and the cooling temperature is 10-25 degrees.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0017] The method of this invention is simple to operate, uses a small amount of organic solvent and can be completely recovered, and produces sodium pyruvate that is white in color with a content of over 99.6% and a one-time yield of about 96%, which is fully capable of large-scale industrial production. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0019] Example 1:

[0020] Lactic acid oxidase catalyzes the conversion of lactic acid into an enzyme inoculum containing sodium pyruvate. After the reaction is complete, the solution is passed through a ceramic membrane. Activated carbon (0.3% of the filtrate mass) is added to the filtrate for decolorization. The solution is then concentrated under reduced pressure at 60°C until the sodium pyruvate content is approximately 600 g / L, followed by spray drying. Anhydrous ethanol is added to the spray-dried product at a weight ratio of 3:1 (anhydrous ethanol: crude sodium pyruvate). The mixture is stirred and refluxed at 60°C for 1 hour, then cooled to 20°C and slowly stirred to crystallize for 1 hour. After centrifugation, the filter cake is washed with anhydrous ethanol and then vacuum dried at 60°C. The produced sodium pyruvate is white in color, with a purity of 99.8%, and a first-pass yield of approximately 98%.

[0021] Example 2:

[0022] Lactic acid oxidase catalyzes the conversion of lactic acid into an enzyme inoculum containing sodium pyruvate. After the reaction is complete, the solution is passed through a ceramic membrane. Activated carbon (0.3% of the filtrate mass) is added to the filtrate for decolorization. The solution is then concentrated under reduced pressure at 60°C until the sodium pyruvate content is approximately 600 g / L, followed by spray drying. Anhydrous methanol is added to the spray-dried product at a weight ratio of 5:1 (anhydrous methanol:crude sodium pyruvate). The mixture is stirred and refluxed at 50°C for 1 hour, then cooled to 15°C and slowly stirred to crystallize for 1 hour. After centrifugation, the filter cake is washed with anhydrous methanol and then vacuum dried at 60°C. The produced sodium pyruvate is white in color, has a purity of 99.6%, and a first-pass yield of approximately 96%.

[0023] Example 3:

[0024] Lactic acid oxidase catalyzes the conversion of lactic acid into an enzyme invertase containing sodium pyruvate. After the reaction is complete, the solution is passed through a ceramic membrane. Activated carbon (0.3% of the filtrate mass) is added to the filtrate for decolorization. The solution is then concentrated under reduced pressure at 60°C until the sodium pyruvate content is approximately 600 g / L, followed by spray drying. Acetone is added to the spray-dried product at a weight ratio of 5:1 (acetone:crude sodium pyruvate). The mixture is stirred and refluxed at 40°C for 1 hour, then cooled to 25°C and slowly stirred to crystallize for 1 hour. After centrifugation, the filter cake is washed with acetone and then vacuum dried at 60°C. The produced sodium pyruvate is white in color, has a purity of 99.8%, and a first-pass yield of approximately 97%.

[0025] The contents described in this specification are merely an enumeration of the implementation forms of the inventive concept, and the scope of protection of this invention should not be regarded as limited to the specific forms described in the embodiments.

Claims

1. A method for separating and extracting sodium pyruvate from the conversion solution of enzymatic production of sodium pyruvate, characterized in that... Using an enzyme conversion solution containing sodium pyruvate obtained by lactate oxidase catalyzing the production of sodium pyruvate from lactic acid, the enzyme conversion solution is subjected to sterilization, concentration, spray drying, and organic solvent extraction, including the following steps: 1) The enzyme conversion solution containing sodium pyruvate was filtered through a ceramic membrane to remove bacterial cells; 2) Add activated carbon to the filtrate from step 1) for decolorization; 3) Then, the solution is concentrated by vacuum distillation to concentrate the sodium pyruvate content in the enzyme conversion solution to 500-700 g / L; 4) Spray drying; 5) Add organic solvent to the spray-dried product, heat and stir under reflux for extraction, cool to room temperature, centrifuge to remove organic solvent, and dry to obtain pure sodium pyruvate. The organic solvent mentioned in step 5) is one or a mixture of methanol, ethanol, or acetone; In step 5), the heating and stirring reflux temperature is 40-80℃, the stirring time is 0.8-2 hours, and the cooling temperature is 10-25℃.

2. The method for separating and extracting sodium pyruvate from the conversion solution of enzymatic production of sodium pyruvate as described in claim 1, characterized in that... In step 3), the temperature of vacuum distillation is 55-70℃, so that the sodium pyruvate content in the enzyme conversion solution is concentrated to (600±20) g / L.

3. The method for separating and extracting sodium pyruvate from the conversion solution of enzymatic production of sodium pyruvate as described in claim 1, characterized in that... In step 5), the weight ratio of sodium pyruvate to organic solvent in the spray-dried product is 1:2~5.