A process for the co-production of l-ascorbyl palmitate and biodiesel

Abstract

The application discloses a process method for co-production of L-ascorbyl palmitate and biodiesel, which comprises the following steps: performing a first enzyme catalysis reaction on L-ascorbic acid and palm oil to obtain a first enzyme catalysis mixture; performing layer separation and vacuum distillation treatment on the first enzyme catalysis mixture to obtain a first enzyme catalysis product; performing a second enzyme catalysis reaction on the first enzyme catalysis product to obtain a second enzyme catalysis mixture; and performing distillation treatment on the second enzyme catalysis mixture under online dehydration conditions to obtain L-ascorbyl palmitate and biodiesel; the application utilizes the solubility of L-ascorbic acid in short-chain alcohol, promotes mutual solubility of L-ascorbic acid and palm oil, adopts two-step enzyme catalysis reaction under mild conditions, realizes reaction of L-ascorbic acid and palm oil catalyzed by lipase to generate L-ascorbyl palmitate, and realizes reaction of palm oil and short-chain alcohol catalyzed by lipase to generate biodiesel, so that integrated co-production of various high-value-added products is realized.

Description

Technical Field

[0001] This invention relates to the field of biochemical engineering, specifically to a process for the co-production of L-ascorbate palmitate and biodiesel. Background Technology

[0002] L-Ascorbic acid is a commonly used natural antioxidant. Its molecular structure contains active allyl alcohols, making it easily oxidized by external factors such as light and temperature, thus exhibiting strong antioxidant capabilities. However, due to its strong hydrophilicity, L-ascorbic acid is poorly soluble in hydrophobic liquids such as oils, which greatly limits its application. Converting L-ascorbic acid into its fatty acid esters can solve this problem. L-ascorbic acid fatty acid esters not only retain the antioxidant properties and physiological activity of L-ascorbic acid, but also significantly improve its solubility and stability in non-aqueous systems, increasing its ability to scavenge free radicals. Therefore, it has become a highly efficient, safe, and non-toxic antioxidant.

[0003] Currently, research on the preparation of L-ascorbic acid fatty acid esters by chemical methods using fatty acids such as palmitic acid, stearic acid, and lauric acid as acyl donors is relatively extensive. Bioenzymatic methods have mild reaction conditions, high specificity, and simple product separation and purification methods, and the enzyme-catalyzed synthesis of L-ascorbic acid fatty acid esters has a promising prospect for development and application.

[0004] In the process of preparing L-ascorbic acid fatty acid esters by bio-enzymatic method, due to the strong hydrophilicity of L-ascorbic acid, it is difficult to be miscible with acyl donors in the preparation of long-chain fatty acid esters. Therefore, it is often necessary to introduce hydrophobic solvents, including tert-butanol and acetone, to promote the reaction. This method requires the introduction of additional organic solvents, which directly increases the operating cost, and the reaction process produces only one product. Summary of the Invention

[0005] To overcome the above-mentioned technical problems, this invention discloses a process for co-producing L-ascorbate palmitate and biodiesel.

[0006] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0007] A process for co-producing L-ascorbate palmitate and biodiesel, comprising the following steps:

[0008] Step 1: L-ascorbic acid and palm oil undergo a primary enzymatic reaction to obtain a primary enzymatic mixture;

[0009] Step 2: The primary enzyme-catalyzed mixture is subjected to layering and vacuum distillation to obtain the primary enzyme-catalyzed product;

[0010] Step 3: The primary enzyme catalytic product is subjected to a secondary enzyme catalytic reaction to obtain a secondary enzyme catalytic mixture;

[0011] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbate palmitate and biodiesel (i.e., palm oil short-chain alcohol ester).

[0012] In the above-described process for co-producing L-ascorbate palmitate and biodiesel, in step 1, the primary enzyme-catalyzed reaction is carried out by reacting a short-chain alcohol with a lipase under the catalysis of a lipase; the lipase is a liquid lipase or an immobilized lipase.

[0013] The above-described process for co-producing L-ascorbic acid palmitate and biodiesel, wherein step 1 employs liquid lipase catalysis; the conditions for the primary enzyme-catalyzed reaction are as follows: the amount of liquid lipase is 300-3000 standard enzyme activity units based on the mass of palm oil, the amount of L-ascorbic acid is 0.2-0.8 times the molar amount of palm oil, the amount of short-chain alcohol is 3-5 times the molar amount of palm oil, and the water content is 2-5% based on the mass of palm oil; the primary enzyme-catalyzed reaction is carried out in a single-stage or multi-stage enzyme reactor, with the temperature controlled at 35-60℃, and the reaction time is 6-18 hours. Typically, the conversion rate of L-ascorbic acid reaches over 80%, and the yield of short-chain alcohol esters from palm oil is over 90% of the theoretical yield.

[0014] The above-described process for co-producing L-ascorbic acid palmitate and biodiesel, wherein step 1 employs immobilized lipase catalysis; the conditions for the primary enzyme-catalyzed reaction are as follows: the amount of immobilized lipase is 300-2000 standard enzyme activity units based on the mass of palm oil, the amount of L-ascorbic acid is 0.2-0.8 times the molar amount of palm oil, and the amount of short-chain alcohol is 3-65 times the molar amount of palm oil; the primary enzyme-catalyzed reaction is carried out in a single-stage or multi-stage circulating reactor, with the temperature controlled at 35-60℃, and the reaction time is 5-18 hours. Typically, the conversion rate of L-ascorbic acid reaches over 90%, and the yield of short-chain palm oil esters is over 95% of the theoretical yield.

[0015] In the above-mentioned process for co-producing L-ascorbate palmitate and biodiesel, the short-chain alcohol in the primary enzyme-catalyzed reaction is added in steps, and the step-by-step addition condition is that the short-chain alcohol is added at a uniform rate within 2 hours.

[0016] In the above-mentioned process for co-producing L-ascorbate palmitate and biodiesel, the primary enzyme-catalyzed mixture obtained after the primary enzyme-catalyzed reaction needs to have residual short-chain alcohols and other substances removed before undergoing a secondary enzyme-catalyzed reaction in order to obtain purer biodiesel. In step 2, the layering process can be centrifugation or static layering to separate the heavy phase containing lipase and the light phase containing crude biodiesel. The light phase is further distilled under reduced pressure to obtain the residue for subsequent step 3. The purpose of the reduced pressure distillation is to remove excess short-chain alcohols.

[0017] In the above-described process for co-producing L-ascorbic acid palmitate and biodiesel, in step 3, the secondary enzyme-catalyzed reaction is carried out under the catalysis of an immobilized lipase. The amount of immobilized lipase used is 300-2000 standard enzyme activity units based on the mass of palm oil. The secondary enzyme-catalyzed reaction is carried out in a single-stage or multi-stage circulating reactor at a temperature controlled at 35-60°C for 10-18 hours. Preferably, the single-stage or multi-stage circulating reactor is coupled with an online dehydration device to remove moisture from the reaction system online. Under normal conditions, the conversion rate of L-ascorbic acid reaches over 95%, and the yield of short-chain palm oil esters is over 98% of the theoretical yield.

[0018] In the above-mentioned process for co-producing L-ascorbyl palmitate and biodiesel, in the reaction process of step 4, molecular sieves and membranes are introduced to carry out online dehydration to remove water from the reaction system online, thereby obtaining qualified L-ascorbyl palmitate and biodiesel; the distillate obtained by distillation is a short-chain alcohol ester of palm oil, which is biodiesel, and the bottom liquid is L-ascorbyl palmitate.

[0019] In the above-described process for co-producing L-ascorbic acid palmitate and biodiesel, the short-chain alcohol is methanol, ethanol, propanol, or butanol.

[0020] In the above-described process for co-producing L-ascorbate palmitate and biodiesel, the lipases include lipases derived from yeast cells, mold cells, bacteria, or other microorganisms.

[0021] L-Ascorbic acid, a commonly used natural antioxidant, is highly hydrophilic and poorly soluble in hydrophobic liquids such as oils, which greatly limits its application in lipid-soluble hydrophobic systems. To improve the performance of L-ascorbic acid, enhancing its catalytic conversion rate via enzymatic methods is crucial for the preparation of L-ascorbic acid fatty acid esters. Currently, fatty acids such as palmitic acid, stearic acid, and lauric acid are directly used as acyl donors. However, during preparation, these acyl donors are difficult to miscible with L-ascorbic acid. Therefore, hydrophobic solvents are usually introduced to improve the hydrophobicity of the reaction system. Traditional hydrophobic solvents include tert-butanol and acetone, but introducing these solvents increases operating costs and results in a limited variety of products.

[0022] When performing primary or secondary enzyme-catalyzed reactions, biocatalysts can be selected, including various lipases, such as liquid lipases, immobilized lipases, and lipase-containing bacterial cells or immobilized bacterial cells. Lipase catalysts have advantages such as wide adaptability to raw materials and mild reaction conditions, and are particularly suitable for the enzyme-catalyzed reactions of high-acid-value oils. Liquid lipases are free liquids, relatively inexpensive, usually contain a high water content, and have a high reaction rate for the enzyme catalysis of oils. Compared with liquid lipases, immobilized lipases have advantages such as better stress resistance and easier recovery. This invention employs a two-step enzyme-catalyzed reaction, including a primary enzyme-catalyzed reaction using liquid lipase or immobilized lipase, and a secondary enzyme-catalyzed reaction using immobilized lipase. The liquid lipase catalysis is carried out in an oil-water emulsion system, with the liquid lipase dispersed at the oil-water interface to catalyze the reaction, thereby promoting enzyme catalytic efficiency. Furthermore, the immiscibility of oil and water causes emulsification of the reaction system, which can lead to protein detachment and inactivation of the immobilized lipase prepared by adsorption, resulting in a decrease in apparent enzyme activity. Therefore, this invention uses immobilized lipase... During enzyme catalysis, the reaction system is a solvent-free system, meaning no organic solvents such as water are added as a reaction medium. The reaction system is homogeneous and emulsification does not occur. It should be noted that water is generated during the esterification reactions of L-ascorbic acid with palm oil and palm oil with short-chain alcohols. Since esterification is an equilibrium reaction, to further promote the reaction towards esterification, the reaction system can be coupled with an online dehydration device during the secondary enzyme catalysis reaction to remove water from the system online. This rapidly pushes the reaction to equilibrium, effectively improving the conversion rate of L-ascorbic acid and the product yield.

[0023] The beneficial effects of this invention are as follows: This invention utilizes the solubility of L-ascorbic acid in short-chain alcohols to promote the miscibility of L-ascorbic acid and palm oil. A two-step enzymatic catalytic reaction is employed under mild conditions to achieve the simultaneous catalytic reaction of L-ascorbic acid and palm oil to produce L-ascorbate palmitate via lipase catalysis, and the simultaneous catalytic reaction of palm oil and short-chain alcohols to produce biodiesel. This achieves integrated co-production of multiple high-value-added products, significantly improving the added value of palm oil and the overall economic benefits of the reaction process. The entire reaction process is environmentally friendly, maximizing the preservation of the bioactivity of L-ascorbic acid while fully utilizing the raw material components, greatly improving enzyme catalytic efficiency and product yield. Simultaneously, short-chain alcohols are directly used instead of conventional organic solvents during the reaction, eliminating the need for additional organic solvents such as tert-butanol and acetone used in conventional processes. This solves the problem of the poor solubility of L-ascorbic acid in palm oil requiring the addition of organic solvents, and eliminates the cumbersome process of adding organic solvents in the conventional L-ascorbate palmitate preparation process. The overall economic benefits are significantly improved, and this process has excellent market application prospects. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 This is a schematic diagram of the reaction process in the process method of the present invention;

[0026] Figure 2 This is a schematic diagram of the main process flow of the present invention. Detailed Implementation

[0027] The present invention will be further described below through specific embodiments to make the technical solutions of the present invention easier to understand and master, rather than to limit the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0028] Example 1: This example provides a process for co-producing L-ascorbate palmitate and biodiesel, which includes the following steps:

[0029] Step 1: 10g of palm oil, 2% water (based on the oil mass), 0.2 times the molar amount of L-ascorbic acid (based on the oil molar amount), 400 standard enzyme activity units of liquid lipase derived from Aspergillus oryzae (based on the oil mass), and 3 times the molar amount of methanol (based on the oil molar amount) are placed in a single-stage or multi-stage enzyme reactor and reacted at 35°C for 10 hours to obtain a primary enzyme-catalyzed mixture; wherein, the L-ascorbic acid conversion rate in the primary enzyme-catalyzed mixture reaches 80%, and the palm oil methyl ester yield is 90%;

[0030] Step 2: After centrifugation and separation of the primary enzyme catalytic mixture, the heavy phase and the light phase are separated. The light phase is then further subjected to vacuum distillation to remove excess short-chain alcohols, thereby obtaining the primary enzyme catalytic product.

[0031] Step 3: Place the primary enzyme catalytic product in a single-stage or multi-stage circulating reactor, add an immobilized lipase from Aspergillus oryzae with 300 standard enzyme activity units based on the oil mass, control the reaction temperature at 55°C, and react for 12 hours to obtain a secondary enzyme catalytic mixture.

[0032] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbic acid palmitate and biodiesel; wherein the L-ascorbic acid conversion rate reaches 95% and the palm oil methyl ester yield is 98%.

[0033] Example 2: This example provides a process for co-producing L-ascorbate palmitate and biodiesel, which includes the following steps:

[0034] Step 1: 20g of palm oil, 5% water (based on the oil mass), 0.5 times the molar amount of L-ascorbic acid (based on the oil molar amount), 2000 standard enzyme activity units of liquid lipase derived from *Candida antarctica* (based on the oil mass), and 4 times the molar amount of ethanol (based on the oil molar amount) are placed in a single-stage or multi-stage enzyme reactor and reacted at 45°C for 18 hours to obtain a primary enzyme-catalyzed mixture; wherein, the L-ascorbic acid conversion rate in the primary enzyme-catalyzed mixture reaches 85%, and the palm oil ethyl ester yield is 90%;

[0035] Step 2: After centrifugation and separation of the primary enzyme catalytic mixture, the heavy phase and the light phase are separated. The light phase is then further subjected to vacuum distillation to remove excess short-chain alcohols, thereby obtaining the primary enzyme catalytic product.

[0036] Step 3: Place the primary enzyme catalytic product in a single-stage or multi-stage circulating reactor, add an immobilized lipase from Aspergillus oryzae with 2000 standard enzyme activity units based on the oil mass, control the reaction temperature at 45°C, and react for 12 hours to obtain a secondary enzyme catalytic mixture.

[0037] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbic acid palmitate and biodiesel; wherein the L-ascorbic acid conversion rate reaches 98% and the palm oil ethyl ester yield is 98%.

[0038] Example 3: This example provides a process for co-producing L-ascorbate palmitate and biodiesel, which includes the following steps:

[0039] Step 1: 30g of palm oil, 0.8 times the molar amount of L-ascorbic acid, 1500 standard enzyme activity units of immobilized lipase derived from Rhizomucormiehei based on the oil mass, and 5 times the molar amount of methanol based on the oil mass are placed in a single-stage or multi-stage circulating reactor and reacted at 55°C for 10 hours to obtain a primary enzyme-catalyzed mixture; wherein, the L-ascorbic acid conversion rate in the primary enzyme-catalyzed mixture reaches 91%, and the palm oil methyl ester yield is 96%;

[0040] Step 2: After centrifugation and separation of the primary enzyme catalytic mixture, the heavy phase and the light phase are separated. The light phase is then further subjected to vacuum distillation to remove excess short-chain alcohols, thereby obtaining the primary enzyme catalytic product.

[0041] Step 3: Place the primary enzyme-catalyzed product in a single-stage or multi-stage circulating reactor, add 1000 standard enzyme activity units based on the oil mass from Candida antarctica, control the reaction temperature at 55°C, and react for 10 hours to obtain a secondary enzyme-catalyzed mixture.

[0042] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbic acid palmitate and biodiesel; wherein the L-ascorbic acid conversion rate reaches 96% and the palm oil methyl ester yield is 98%.

[0043] Example 4: This example provides a process for co-producing L-ascorbate palmitate and biodiesel, which includes the following steps:

[0044] Step 1: 50g of palm oil, 0.2 times the molar amount of L-ascorbic acid (based on the oil content), 2000 standard enzyme activity units of immobilized lipase derived from *Rhizopus cordata* based on the oil content, and 5 times the molar amount of butanol (based on the oil content) are placed in a single-stage or multi-stage circulating reactor and reacted at 50°C for 15 hours to obtain a primary enzyme-catalyzed mixture. The butanol is added to the reactor at a uniform flow rate during the first 2 hours. The primary enzyme-catalyzed mixture achieves a 90% conversion rate of L-ascorbic acid and a 95% yield of butyl palm oil.

[0045] Step 2: After centrifugation and separation of the primary enzyme catalytic mixture, the heavy phase and the light phase are separated. The light phase is then further subjected to vacuum distillation to remove excess short-chain alcohols, thereby obtaining the primary enzyme catalytic product.

[0046] Step 3: Place the primary enzyme-catalyzed product in a single-stage or multi-stage circulating reactor, add 1000 standard enzyme activity units based on the oil mass of an immobilized lipase from *Aspergillus oryzae*, control the reaction temperature at 55°C, and react for 12 hours to obtain a secondary enzyme-catalyzed mixture; during the reaction, the following measures are taken: Figure 2 The online dehydration process shown;

[0047] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbic acid palmitate and biodiesel; wherein the L-ascorbic acid conversion rate reaches 96% and the palm oil butyl ester yield is 98%.

[0048] Example 5: This example provides a process for co-producing L-ascorbate palmitate and biodiesel, which includes the following steps:

[0049] Step 1: 30g of palm oil, 4% water (based on the oil mass), 0.8 times the molar amount of L-ascorbic acid (based on the oil molar amount), 1800 standard enzyme activity units of liquid lipase derived from *Candida antarctica* (based on the oil mass), and 6 times the molar amount of ethanol (based on the oil molar amount) are placed in a single-stage or multi-stage enzyme reactor and reacted at 45°C for 16 hours to obtain a primary enzyme-catalyzed mixture; wherein, the L-ascorbic acid conversion rate in the primary enzyme-catalyzed mixture reaches 80%, and the palm oil ethyl ester yield is 92%;

[0050] Step 2: After centrifugation and separation of the primary enzyme catalytic mixture, the heavy phase and the light phase are separated. The light phase is then further subjected to vacuum distillation to remove excess short-chain alcohols, thereby obtaining the primary enzyme catalytic product.

[0051] Step 3: Place the primary enzyme-catalyzed product in a single-stage or multi-stage circulating reactor, add an immobilized lipase from Candida antarctica with 1800 standard enzyme activity units based on the oil mass, control the reaction temperature at 55°C, and react for 18 hours to obtain a secondary enzyme-catalyzed mixture.

[0052] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbic acid palmitate and biodiesel; wherein the L-ascorbic acid conversion rate reaches 97% and the palm oil ethyl ester yield is 99%.

[0053] Example 6: This example provides a process for co-producing L-ascorbate palmitate and biodiesel, which includes the following steps:

[0054] Step 1: 2g of palm oil, 0.3 times the molar amount of L-ascorbic acid based on the oil content, 900 standard enzyme activity units of immobilized lipase derived from Aspergillus oryzae based on the oil content, and 4 times the molar amount of methanol based on the oil content are placed in a single-stage or multi-stage circulating reactor and reacted at 45°C for 12 hours to obtain a primary enzyme-catalyzed mixture; wherein, the L-ascorbic acid conversion rate in the primary enzyme-catalyzed mixture reaches 92%, and the palm oil methyl ester yield is 95%;

[0055] Step 2: After centrifugation and separation of the primary enzyme catalytic mixture, the heavy phase and the light phase are separated. The light phase is then further subjected to vacuum distillation to remove excess short-chain alcohols, thereby obtaining the primary enzyme catalytic product.

[0056] Step 3: Place the primary enzyme-catalyzed product in a single-stage or multi-stage circulating reactor, add an immobilized lipase from *Candida antarctica* with 2000 standard enzyme activity units based on the oil mass, control the reaction temperature at 50°C, and react for 18 hours to obtain a secondary enzyme-catalyzed mixture; during the reaction, the following measures are taken: Figure 2 The online dehydration process shown;

[0057] Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbic acid palmitate and biodiesel; wherein the L-ascorbic acid conversion rate reaches 97% and the palm oil methyl ester yield is 99%.

[0058] This invention utilizes the solubility of L-ascorbic acid in short-chain alcohols to promote the miscibility of L-ascorbic acid with palm oil. A two-step enzymatic reaction is employed under mild conditions to simultaneously catalyze the reaction of L-ascorbic acid and palm oil to produce L-ascorbyl palmitate via lipase catalysis, and simultaneously catalyze the reaction of palm oil with short-chain alcohols to produce biodiesel. This achieves integrated co-production of multiple high-value-added products, significantly improving the overall economic efficiency of the process. The entire reaction process is environmentally friendly, maximizing the preservation of the bioactivity of L-ascorbic acid while fully utilizing the raw material components, greatly improving enzyme catalytic efficiency and product yield. Furthermore, the reaction process does not require the introduction of organic solvents such as tert-butanol and acetone used in conventional processes, significantly enhancing overall economic benefits. This process has excellent prospects for market promotion and application.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solution of the present invention, or modify it into equivalent embodiments, without departing from the scope of the present invention, using the disclosed technical means and content. Therefore, all equivalent changes made based on the shape, structure, and principle of the present invention without departing from the scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A process for co-producing L-ascorbate palmitate and biodiesel, characterized in that, It includes the following steps: Step 1: L-ascorbic acid and palm oil undergo a primary enzymatic reaction to obtain a primary enzymatic mixture; Step 2: The primary enzyme-catalyzed mixture is subjected to layering and vacuum distillation to obtain the primary enzyme-catalyzed product; Step 3: The primary enzyme catalytic product is subjected to a secondary enzyme catalytic reaction to obtain a secondary enzyme catalytic mixture; Step 4: The secondary enzyme-catalyzed mixture is distilled under online dehydration conditions to obtain L-ascorbate palmitate and biodiesel; In step 1, the primary enzyme-catalyzed reaction is carried out by reacting with a short-chain alcohol under the catalysis of lipase; The lipase is a liquid lipase or an immobilized lipase. Step 1 uses immobilized lipase catalysis; The conditions for the primary enzyme-catalyzed reaction are as follows: the amount of immobilized lipase is 300 to 2000 standard enzyme activity units based on the mass of palm oil, the amount of L-ascorbic acid is 0.2 to 0.8 times the molar amount of palm oil, and the amount of short-chain alcohol is 3 to 65 times the molar amount of palm oil. The primary enzyme-catalyzed reaction is carried out in a single-stage or multi-stage circulating reactor, with the temperature controlled at 35-60°C and the reaction time being 5-18 hours. Step 1 uses liquid lipase catalysis; The conditions for the primary enzyme-catalyzed reaction are as follows: the amount of liquid lipase is 300-3000 standard enzyme activity units based on the mass of palm oil; the amount of L-ascorbic acid is 0.2-0.8 times the molar amount of palm oil; the amount of short-chain alcohol is 3-5 times the molar amount of palm oil; and the water content is 2-5% of the mass of palm oil. The primary enzyme catalytic reaction is carried out in a single-stage or multi-stage enzyme reactor, with the temperature controlled at 35~60℃ and the reaction time being 6~18 hours. The short-chain alcohol in the first enzyme-catalyzed reaction was added in steps, and the step-by-step addition condition was that the short-chain alcohol was added at a constant rate over 2 hours. In step 3, the secondary enzyme catalytic reaction is carried out under the catalysis of immobilized lipase, and the amount of immobilized lipase is 300-2000 standard enzyme activity units based on the mass of palm oil. The secondary enzyme catalytic reaction is carried out in a single-stage or multi-stage circulating reactor, with the temperature controlled at 35~60℃ and the reaction time being 10~18 hours.

2. The process for co-producing L-ascorbate palmitate and biodiesel according to claim 1, characterized in that, The short-chain alcohol is methanol, ethanol, propanol, or butanol.

3. The process for co-producing L-ascorbate palmitate and biodiesel according to claim 2, characterized in that, The lipases include those derived from yeast cells, mold cells, and bacteria.

Images