Method for preparing formic acid from biomass sugar

Abstract

The invention discloses a method for preparing formic acid from biomass sugar, which comprises the following steps: S1, mixing magnesium salt and L-ascorbic acid, and calcining to obtain nano magnesium oxide particles; s2, biomass sugar, hydrogen peroxide and the nanometer magnesium oxide particles are added into a solvent for a reaction, and formic acid is obtained. The biomass sugar raw material adopted by the method is low in cost, the catalyst formic acid selectivity is high, the prepared formic acid yield is high, the production process is simple and high in practicability, the problem that the biomass sugar lacks practical application can be solved, and the whole production process is clean and environmentally friendly.

Description

Technical Field

[0001] The 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 combined with hydrogen peroxide to catalyze and oxidize biomass sugar. Background Art

[0002] Formic acid (chemical formula HCOOH) is a common organic acid, which is widely used in medicine, pesticides, dyes, leather and other industries. However, the cost of raw materials used in the preparation process of formic acid is relatively high, such as methanol, carbon monoxide, sodium hydroxide, etc. In addition, the current formic acid production method is often difficult to obtain a high yield of formic acid products. This not only increases the production cost, but also affects the quality and market competitiveness of the product. In addition, the traditional formic acid production method is complex and difficult to operate. For example, the methanol carbonyl synthesis method needs to react in the presence of a precious metal catalyst, and the selection and loading of the active components of the catalyst and the optimization of the reaction conditions have an important influence on the yield and purity of formic acid. However, the deactivation and regeneration problems of the catalyst, as well as the precise control of the reaction conditions, increase the difficulty of the process operation.

[0003] In summary, the existing formic acid preparation methods have a series of problems such as high cost, low product yield, and difficult process operation. In order to solve 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 increase the yield of formic acid products. Summary of the invention

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

[0005] In order 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 magnesium salt to L-ascorbic acid is 1:0.1-10. In the present invention, the molar ratio of magnesium salt to 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, 1:10. The molar ratio of magnesium salt to 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, 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 1-6h. In the present invention, the calcination temperature may be, but is not limited to, 600°C, 650°C, 700°C, 750°C, 800°C. The calcination time may be, but is not limited to, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h.

[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, so that the biomass sugar can have practical application value.

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

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

[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, 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, 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 1-6h. 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, 80°C. The reaction time may be, but is not limited to, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h.

[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 formic acid solution and solid products 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 them, which 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, and the biomass sugar conversion rate is high, which 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 whole process not only improves the economic value of the product, but also better solves the problem that biomass sugar is difficult to utilize. The whole production process is relatively clean and environmentally friendly, and is easy for industrial production. DETAILED DESCRIPTION

[0023] The present invention provides a method for preparing formic acid from biomass sugar, and the present invention 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 invention and are not used to limit the scope of the present invention.

[0024] The formic acid product in the following examples, the yield calculation method is as follows:

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

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

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

[0028] The percentages in the following examples are by mass unless otherwise specified.

[0029] Example 1

[0030] S1. Preparation of catalyst:

[0031] 10 mmol of magnesium nitrate and 20 mmol of L-ascorbic acid were mixed, then calcined at 700° C. for 2 h, and ground to obtain nano magnesium oxide particles.

[0032] S2. Preparation of formic acid:

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

[0034] Example 2

[0035] S1. Preparation of catalyst:

[0036] 10 mmol of magnesium nitrate and 30 mmol of L-ascorbic acid were mixed, then calcined at 700° C. for 2 h, and ground to obtain nano magnesium oxide particles.

[0037] S2. Preparation of formic acid:

[0038] First, 0.1g of xylose was dissolved in 20ml of deionized water, and then 200uL of hydrogen peroxide solution (the original concentration of hydrogen peroxide was 30wt%) was added, followed by 0.2g of nano-magnesium oxide particles prepared by S1, and the reaction raw materials were loaded into a thick-walled pressure-resistant tube, and after the thick-walled pressure-resistant tube was sealed, it was heated to 40°C and reacted for 240min, with a stirring speed of 500r / min. After the reaction was completed, liquid phase mass spectrometry (HPLC, Agilent) was used for qualitative and quantitative analysis. The results were: the xylose conversion rate was 100%, the formic acid yield was 95%, and the formic acid selectivity was 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] Take 0.1g of glucose and dissolve it in 30ml of deionized water, add 300uL of hydrogen peroxide solution (hydrogen peroxide concentration 30wt%). Put it into a thick-walled pressure-resistant tube, add 0.1g of nano-magnesium oxide particles prepared by S1. After sealing the thick-walled pressure-resistant tube, heat it to 40℃ and react for 240min, stirring at 500r / min. After the reaction, liquid phase mass spectrometry (HPLC, Agilent) is used for qualitative and quantitative analysis. The results are: glucose conversion rate is 100%, formic acid yield is 100%, and formic acid selectivity is 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 are as follows: the xylose conversion rate is 90%, the formic acid yield is 80%, and the formic acid selectivity is 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: the xylose conversion rate was 88%, the formic acid yield was 89%, and the 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 are as follows: the xylose conversion rate is 100%, the formic acid yield is 90%, and the formic acid selectivity is 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] Take 0.1g of xylose and dissolve it in 10ml of deionized water, add 100uL of hydrogen peroxide solution (hydrogen peroxide concentration 30wt%), and then add 0.1g of magnesium nitrate to obtain the reaction raw material. The reaction raw material is loaded into a thick-walled pressure-resistant tube, and after the thick-walled pressure-resistant tube is sealed, it is heated to 40°C for reaction for 240min, and the stirring speed is 500r / min. After the reaction is completed, liquid phase mass spectrometry (HPLC, Agilent) is used for qualitative and quantitative analysis. The results are: the xylose conversion rate is 20%, the formic acid yield is 10%, and the formic acid selectivity is 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] Take 0.1g of xylose and dissolve it in 10ml of deionized water, add 100uL of hydrogen peroxide solution (hydrogen peroxide concentration 30wt%), and then add 0.1g of L-ascorbic acid to obtain the reaction raw material. The reaction raw material is loaded into a thick-walled pressure-resistant tube, and after the thick-walled pressure-resistant tube is sealed, it is heated to 40°C for reaction for 240min, and the stirring speed is 500r / min. After the reaction is completed, liquid phase mass spectrometry (HPLC, Agilent) is used for qualitative and quantitative analysis. The results are: xylose conversion rate is 0%, formic acid yield is 0%, and formic acid selectivity is 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 to 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 functions.

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, characterized in that: The calcination conditions include: temperature of 600-800° C. and time of 1-6 hours.

5. The method according to claim 1, characterized in that 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 adding 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.