A method for producing formic acid using biomass sugars

Abstract

The application discloses a method for preparing formic acid by using biomass sugar, and the preparation method comprises the following steps: S1, mixing a magnesium salt and L-ascorbic acid and calcining to obtain nano magnesium oxide particles; S2, adding biomass sugar, hydrogen peroxide and the nano magnesium oxide particles into a solvent to react, and obtaining formic acid. The method has the advantages of low cost of biomass sugar raw material, high selectivity of the catalyst formic acid, high yield of prepared formic acid, simple production process, strong practicability, and the like, can solve the problem of lack of practical application of biomass sugar, and the whole production process is relatively clean and environmentally friendly.

Description

Technical Field

[0001] The present invention belongs to the field of biochemistry, and specifically relates to a method for preparing formic acid by utilizing biomass sugar, in particular to a method for preparing formic acid by utilizing magnesium oxide in combination with hydrogen peroxide to catalyze the oxidation of biomass sugar. Background Art

[0002] Formic acid (chemical formula HCOOH) is a common organic acid that is widely used in industries such as medicine, pesticides, dyes, and leather. However, the raw materials used in the preparation of formic acid are relatively expensive, such as methanol, carbon monoxide, and sodium hydroxide. In addition, current formic acid production methods often make it difficult to obtain formic acid products in high yields. This not only increases production costs but also affects product quality and market competitiveness. In addition, traditional formic acid production methods are complex and difficult to operate. For example, the methanol carbonylation process requires the presence of a precious metal catalyst to react. The selection and loading of the active components of the catalyst and the optimization of the reaction conditions have a significant impact on the yield and purity of formic acid. However, the deactivation and regeneration of the catalyst, as well as the precise control of the reaction conditions, increase the difficulty of process operation.

[0003] In summary, existing formic acid production methods have a series of problems such as high cost, low product yield, and difficult process operation. To address these problems, it is necessary to develop a more environmentally friendly, efficient and economical formic acid production method to reduce energy consumption, reduce pollution, and improve the yield of formic acid product. Summary of the Invention

[0004] The present invention addresses the problems of high cost, low product yield, and difficult process operation in existing formic acid preparation methods, and provides a new formic acid preparation method. The method adopts low raw material cost, high formic acid selectivity of the catalyst, high yield of the prepared formic acid, simple production process, strong practicality, and can solve the problem of lack of practical application fields of biomass sugars such as xylose. In addition, the entire production process is relatively clean and environmentally friendly.

[0005] To solve the above technical problems, the present invention provides a method for preparing formic acid using biomass sugar, comprising the following steps:

[0006] S1, mixing magnesium salt and L-ascorbic acid and calcining to obtain nano magnesium oxide particles;

[0007] S2, adding biomass sugar, hydrogen peroxide and the nano magnesium oxide particles into a solvent to react and obtain formic acid.

[0008] According to some embodiments of the present invention, in S1, the molar ratio of the magnesium salt to the L-ascorbic acid is 1:0.1-10. In the present invention, the molar ratio of the magnesium salt to the L-ascorbic acid may be, but is not limited to, 1:0.1, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10. The molar ratio of the magnesium salt to the L-ascorbic acid may be, but is not limited to, the following ranges: 1:0.1-5, 1:0.1-8, 1:0.1-10, 1:1-5, 1:1-8, 1:1-10, 1:2-5, 1:2-8, 1:2-10, 1:5-8, or 1:5-10.

[0009] According to some embodiments of the present invention, the magnesium salt may be a soluble magnesium salt. Preferably, the magnesium salt is selected from at least one of magnesium nitrate, magnesium carbonate, magnesium chloride, and magnesium sulfate.

[0010] According to some embodiments of the present invention, the calcination conditions include: a temperature of 600-800°C and a time of 1-6 hours. In the present invention, the calcination temperature may be, but is not limited to, 600°C, 650°C, 700°C, 750°C, or 800°C. The calcination time may be, but is not limited to, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours.

[0011] According to some embodiments of the present invention, the solvent is selected from at least one of deionized water, γ-valerolactone, and acetonitrile.

[0012] According to some embodiments of the present invention, the biomass sugar is selected from at least one of xylose, glucose, arabinose, xylan, and glucan. According to the method of the present invention, the biomass sugar can be fully utilized and has practical application value.

[0013] According to some embodiments of the present invention, in the biomass sugar solution, the concentration of biomass sugar after being added to the solvent is 0.1-1 wt%. In the present invention, the concentration of biomass sugar after being added to the solvent can be, but is not limited to, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1 wt%.

[0014] According to some embodiments of the present invention, the concentration of hydrogen peroxide after being added to the solvent is 0.2-0.3 wt%. In the present invention, the concentration of hydrogen peroxide after being added to the solvent can be, but is not limited to, 0.2 wt%, 0.21 wt%, 0.22 wt%, 0.23 wt%, 0.24 wt%, 0.25 wt%, 0.26 wt%, 0.27 wt%, 0.28 wt%, 0.29 wt%, or 0.3 wt%.

[0015] According to some embodiments of the present invention, the weight ratio of biomass sugar to hydrogen peroxide is 1:0.1-1. In the present invention, the weight ratio of biomass sugar to hydrogen peroxide can be, but is not limited to, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, or 1:1.

[0016] According to some embodiments of the present invention, the weight ratio of biomass sugar to nano-magnesium oxide particles is 1:0.1-10. In the present invention, the weight ratio of biomass sugar to nano-magnesium oxide particles can be, but is not limited to, 1:0.1, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10.

[0017] According to some embodiments of the present invention, the reaction conditions include: a temperature of 20-80° C. and a time of 1-6 hours. In the present invention, the reaction temperature may be, but is not limited to, 20° C., 30° C., 40° C., 50° C., 60° C., 70° C., or 80° C. The reaction time may be, but is not limited to, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours.

[0018] According to some embodiments of the present invention, after the reaction, solid product recovery can be performed, and the recovered solid, i.e., nano-magnesium oxide particle catalyst, can be reused.

[0019] According to some embodiments of the present invention, the reaction is carried out, for example but not limited to, in a thick-walled pressure-resistant tube.

[0020] Beneficial effects of the present invention:

[0021] (1) The present invention uses biomass sugars, such as xylose, as raw materials, and obtains a formic acid solution and a solid product under the catalytic conditions of relatively low concentrations of magnesium oxide and hydrogen peroxide. The formic acid solution can be used for subsequent product conversion. In addition, the recovered solid product can be reused.

[0022] (2) The present invention obtains nano magnesium oxide particles having high activity by mixing magnesium salt with L-ascorbic acid and calcining the mixture. The nano magnesium oxide particles can significantly improve the selectivity and yield of formic acid. In the presence of a lower concentration of catalyst, a shorter reaction time, and a lower reaction temperature, a higher formic acid yield and formic acid selectivity can be obtained. The biomass sugar conversion rate is high, and the nano magnesium oxide has good practical utilization value. The prepared nano magnesium oxide has low alkalinity, does not cause significant pollution to the environment, and can be recycled. The entire process not only improves the economic value of the product, but also better solves the problem of the difficulty in utilizing biomass sugar. The entire production process is relatively clean and environmentally friendly, and is easy to industrialize. DETAILED DESCRIPTION

[0023] The present application provides a preparation method for preparing formic acid by using biomass sugar. The present application is further described below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present application and not to limit the scope of the present application.

[0024] The formic acid product in the following examples is calculated as follows:

[0025] Biomass sugar conversion rate = (amount of reacted biomass sugar ÷ amount of original biomass sugar) x 100%

[0026] Formic acid yield = (amount of obtained formic acid ÷ amount of original biomass sugar) x 100%

[0027] Formic acid selectivity = (amount of obtained formic acid ÷ amount of all obtained substances) x 100%

[0028] The percentage in the following examples is mass percentage unless otherwise specified.

[0029] Example 1

[0030] S1. Preparation of catalyst:

[0031] Take 10 mmol of magnesium nitrate and 20 mmol of L-ascorbic acid, then calcine at a temperature of 700℃ for 2h, and grind to obtain nano-magnesium oxide particles.

[0032] S2. Preparation of formic acid:

[0033] First, dissolve 0.1g of xylose in 10ml of deionized water, then add 100uL of hydrogen peroxide solution (original concentration of hydrogen peroxide is 30wt%), then add 0.1g of nano-magnesium oxide particles prepared by S1, to obtain the reaction raw material. The reaction raw material is loaded into a thick-walled pressure tube, and after the thick-walled pressure tube is sealed, it is heated to 40℃ for 240min, with a stirring speed of 500r / min. After the reaction is completed, qualitative and quantitative analysis is performed by liquid chromatography-mass spectrometry (HPLC, Agilent). The results are as follows: the conversion rate of xylose is 95.23%, the yield of formic acid is 90.11%, and the selectivity of formic acid is 94.62%.

[0034] Example 2

[0035] S1. Preparation of catalyst:

[0036] Take 10 mmol of magnesium nitrate and 30 mmol of L-ascorbic acid, then calcine at a temperature of 700℃ for 2h, and grind to obtain nano-magnesium oxide particles.

[0037] S2. Preparation of formic acid:

[0038] 0.1g of xylose was dissolved in 20ml of deionized water, followed by the addition of 200µL of hydrogen peroxide solution (initial hydrogen peroxide concentration: 30wt%), and then 0.2g of nanomagnesium oxide particles prepared in S1. The reaction materials were placed in a thick-walled pressure-resistant tube, sealed, and heated to 40°C for 240min with stirring at 500rpm. After completion of the reaction, qualitative and quantitative analysis was performed using liquid chromatography-mass spectrometry (HPLC, Agilent). The results showed a xylose conversion of 100%, a formic acid yield of 95%, and a formic acid selectivity of 95%.

[0039] Example 3

[0040] S1. Preparation of catalyst:

[0041] 10 mmol of magnesium nitrate and 40 mmol of L-ascorbic acid were mixed, then calcined at 700° C. for 2 h, and ground to obtain nano-magnesium oxide particles.

[0042] S2. Preparation of formic acid:

[0043] 0.1g of glucose was dissolved in 30ml of deionized water, and 300µL of hydrogen peroxide solution (30wt%) was added. This solution was placed in a thick-walled pressure-resistant tube, and 0.1g of nanomagnesium oxide particles prepared in S1 were added. After sealing the tube, the reaction was heated to 40°C for 240 minutes with a stirring rate of 500 rpm. After the reaction, qualitative and quantitative analysis was performed using liquid chromatography-mass spectrometry (HPLC, Agilent). The results showed a glucose conversion rate of 100%, a formic acid yield of 100%, and a formic acid selectivity of 100%.

[0044] Example 4

[0045] The method of Example 1 was followed, except that 20 mmol of L-ascorbic acid was replaced by 1 mmol of L-ascorbic acid.

[0046] The results were as follows: xylose conversion rate was 90%, formic acid yield was 80%, and formic acid selectivity was 72%.

[0047] Example 5

[0048] The method of Example 1 was followed, except that 20 mmol of L-ascorbic acid was replaced by 10 mmol of L-ascorbic acid.

[0049] The results were as follows: xylose conversion was 88%, formic acid yield was 89%, and formic acid selectivity was 78.32%.

[0050] Example 6

[0051] The method of Example 1 was followed, except that 20 mmol of L-ascorbic acid was replaced by 50 mmol of L-ascorbic acid.

[0052] The results were as follows: xylose conversion rate was 100%, formic acid yield was 90%, and formic acid selectivity was 90%.

[0053] Comparative Example 1

[0054] The method of Example 1 is followed, except that the nano-magnesium oxide particles are replaced with magnesium nitrate, that is:

[0055] Preparation of formic acid:

[0056] 0.1g of xylose was dissolved in 10ml of deionized water, 100µL of hydrogen peroxide solution (30wt%) was added, and then 0.1g of magnesium nitrate was added to obtain the reaction raw material. The reaction raw material was placed in a thick-walled pressure-resistant tube, which was sealed and heated to 40°C for 240min with a stirring speed of 500r / min. After the reaction, qualitative and quantitative analysis was performed using liquid chromatography-mass spectrometry (HPLC, Agilent). The results showed a xylose conversion of 20%, a formic acid yield of 10%, and a formic acid selectivity of 50%.

[0057] Comparative Example 2

[0058] The method of Example 1 is followed, except that the nano-magnesium oxide particles are replaced with L-ascorbic acid, that is:

[0059] Preparation of formic acid:

[0060] 0.1 g of xylose was dissolved in 10 ml of deionized water, 100 μL of hydrogen peroxide solution (30 wt%) was added, and then 0.1 g of L-ascorbic acid was added to obtain the reaction material. The reaction material was placed in a thick-walled pressure-resistant tube, which was sealed and heated to 40°C for 240 minutes with stirring at 500 rpm. After the reaction, qualitative and quantitative analysis was performed using liquid chromatography-mass spectrometry (HPLC, Agilent). The results showed: xylose conversion was 0%, formic acid yield was 0%, and formic acid selectivity was 0%.

[0061] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation of the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for preparing formic acid using biomass sugar, characterized in that: The following steps are involved: S1, mixing magnesium salt and L-ascorbic acid and calcining to obtain nano magnesium oxide particles; S2, adding biomass sugar, hydrogen peroxide and the nano magnesium oxide particles into a solvent to react and obtain formic acid.

2. The method according to claim 1, characterized in that In S1, the molar ratio of magnesium salt to L-ascorbic acid is 1:0.1-10.

3. The method according to claim 1, characterized in that The magnesium salt is selected from at least one of magnesium nitrate, magnesium carbonate, magnesium chloride and magnesium sulfate.

4. The method according to claim 1, wherein The calcination conditions include: temperature of 600-800° C. and time of 1-6 hours.

5. The method according to claim 1, wherein The solvent is selected from at least one of deionized water, γ-valerolactone, and acetonitrile.

6. The method according to claim 1, characterized in that The biomass sugar is selected from at least one of xylose, glucose, arabinose, xylan and glucan; and / or, The concentration of biomass sugar after being added to the solvent is 0.1 to 1 wt%.

7. The method according to claim 1, characterized in that The concentration of hydrogen peroxide after being added to the solvent is 0.2-0.3 wt %.

8. The method according to claim 1, characterized in that The weight ratio of biomass sugar to hydrogen peroxide is 1:0.1-1.

9. The method according to claim 1, characterized in that The weight ratio of biomass sugar to nano magnesium oxide particles is 1:0.1-10.

10. The method according to claim 1, characterized in that The reaction conditions include: temperature of 20-80° C. and time of 1-6 h.