A method for preparing glutaric acid and 3-methylglutaric acid from biomass raw materials

Abstract

The invention discloses a method for preparing glutaric acid and 3-methylglutaric acid from biomass, and belongs to the field of chemical raw material synthesis. Biomass is converted into cyclopentanone, 2,5-hexanedione and 3-methylcyclopentanone at a specific temperature under a reaction system of a metal salt aqueous solution, a noble metal catalyst, an organic solvent and a certain pressure of hydrogen, and the obtained cyclopentanone is oxidized to generate glutaric acid under a reaction system of H2[WO(O)2(OH)2] and hydrogen peroxide at a specific temperature; the obtained 2,5-hexanedione is subjected to an aldol condensation reaction under a sodium carbonate aqueous solution, a noble metal catalyst and a certain pressure of hydrogen reaction system to obtain 3-methylcyclopentanone, and 3-methylcyclopentanone is oxidized to generate 3-methylglutaric acid under a reaction system of H2[WO(O)2(OH)2] and hydrogen peroxide. The present invention uses widely distributed biomass as a substrate, reduces the consumption of fossil energy, and is conducive to the sustainable development of energy; the preparation method of the present invention has mild conditions and high yield, and provides a new way for preparing glutaric acid and 3-methylglutaric acid.

Description

Technical Field

[0001] The invention belongs to the field of chemical raw material synthesis, and specifically relates to a method for preparing glutaric acid and 3-methylglutaric acid by using biomass raw materials. Technical Background

[0002] Glutaric acid and 3-methylglutaric acid are important pharmaceutical and fine chemical intermediates, widely used in nylon fibers, lubricating oils, plasticizers, musk ketone drugs and other fields. In recent years, it has also been found that 3-methylglutaric acid can be used as an extractant for rare earth metal ions and 13 C solid nuclear magnetic spectrum standard compound, so the development and research of glutaric acid and 3-methylglutaric acid synthesis routes have always been valued.

[0003] In the past, there were mainly the following methods for synthesizing glutaric acid: 1) γ-butyrolactone method, which is to react γ-butyrolactone with potassium cyanide at high temperature and then acidify and hydrolyze to obtain the product. Potassium cyanide is a highly toxic chemical, which will bring risks to the large-scale production of glutaric acid; 2) dihydropyran method, which is to react dihydropyran with nitric acid. During the reaction, toxic gas nitrogen oxides will overflow, which is dangerous and harmful to the environment.

[0004] There have been few reports on the synthesis of 3-methylglutaric acid in the past. They mainly use β-methyl-γ-valerolactone, 2-hydroxy-4-methyltetrahydropyran and 3-methyl-1,5-pentanediol as raw materials, and use 60-65% concentration of nitric acid oxidation or air oxidation. During the nitric acid oxidation process, the equipment will be severely corroded, and a large amount of toxic gas will be released, which will seriously pollute the environment. Therefore, this method is limited to prepare 3-methylglutaric acid. Another method is air oxidation. Although the preparation of 3-methylglutaric acid by air oxidation solves the problem of environmental protection, due to the long preparation time and low yield of the target product, the preparation cost is high and it is not worth promoting.

[0005] In recent years, with the increasing depletion of fossil energy, the research and development of new renewable energy has become a major issue facing the world today. Biomass energy has received extensive attention from scientific researchers in recent years due to its many advantages such as sustainability, carbon neutrality, and environmental friendliness. Biomass energy has been considered an important bridge for the transition from fossil energy to renewable energy. The conversion of biomass materials into high-value-added chemicals has been one of the research hotspots in recent years. Summary of the invention

[0006] In view of this, the purpose of this patent is to provide a method for preparing glutaric acid and 3-methylglutaric acid using biomass raw materials.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for preparing glutaric acid from biomass raw materials mainly comprises the following steps:

[0009] (1) The biomass raw material is reacted in a reaction system of a certain concentration of metal salt aqueous solution, a certain amount of A / B supported noble metal catalyst, an organic solvent and a certain pressure of hydrogen at a specific reaction temperature, and the hemicellulose in the biomass raw material is hydrogenated and isomerized into cyclopentanone;

[0010] (2) The cyclopentanone obtained in step (1) undergoes an oxidation reaction in a certain amount of H2[WO(O)2(OH)2] and hydrogen peroxide reaction system at a specific temperature to generate glutaric acid.

[0011] Furthermore, the biomass raw material described in step (1) includes all materials containing hemicellulose, and hemicellulose derivative compounds, such as one or a mixture of two or more of various woods, straws, seaweeds, and xylans; including one or a mixture of two or more of hemicellulose-based platform compounds such as xylose, furfural, and furfuryl alcohol.

[0012] Furthermore, the metal salt in the metal salt aqueous solution described in step (1) includes metal chlorides (such as one or more of potassium chloride, calcium chloride, sodium chloride, magnesium chloride, nickel chloride, and chromium chloride), and metal bromides (such as one or more of potassium bromide, calcium bromide, sodium bromide, magnesium bromide, nickel bromide, and chromium bromide).

[0013] Furthermore, the concentration of the metal salt in the metal salt aqueous solution in step (1) is in the range of 10 wt % to 50 wt %.

[0014] Furthermore, the A / B supported precious metal catalyst described in step (1) includes one or a mixture of two or more of Pd / C, Pd / Al2O3, Pd / SiO2, Pt / C, Pt / Al2O3, Pt / SiO2, Ru / C, Ru / Al2O3, Ru / SiO2, Rh / C, Rh / Al2O3, Rh / SiO2, Ir / C, Ir / Al2O3, and Ir / SiO2.

[0015] Furthermore, the amount of the A / B supported noble metal catalyst added in step (1) is 1% to 15% of the mass of the biomass raw material.

[0016] Furthermore, the organic solvent in step (1) includes one or more of methyl isobutyl ketone, tetrahydrofuran, γ-valerolactone, isopropanol, toluene, cyclohexane, dichloromethane, bromobenzene, ethyl acetate, N,N-dimethylformamide, and dimethyl sulfoxide.

[0017] Furthermore, the volume ratio of the metal salt aqueous solution to the organic solvent in step (1) is (1:0.5) to (1:4).

[0018] Furthermore, the pressure range of the hydrogen in step (1) is 0.1 to 10 MPa.

[0019] Furthermore, the reaction temperature in step (1) is in the range of 150 to 300°C.

[0020] Furthermore, the reaction time of the reaction in step (1) is more than 4 hours.

[0021] Furthermore, in step (1), 5 to 20 mL of a metal salt aqueous solution and 10 to 40 mL of an organic solvent are added to every 50 mg of biomass raw material.

[0022] Furthermore, in step (2), the mass ratio of hydrogen peroxide to H2[WO(O)2(OH)2] ranges from (2:1) to (20:1).

[0023] Furthermore, the reaction temperature in step (2) is in the range of 85 to 100°C.

[0024] Furthermore, the reaction time in step (2) is greater than 12 hours.

[0025] Furthermore, in step (2), the mass ratio of cyclopentanone to H2[WO(O)2(OH)2] is (1:0.5) to (1:2).

[0026] A method for preparing 3-methylglutaric acid from biomass raw materials mainly comprises the following steps:

[0027] (1) The biomass raw material reacts in a reaction system of a certain concentration of metal salt aqueous solution, a certain amount of A / B supported noble metal catalyst, an organic solvent and a certain pressure of hydrogen at a specific reaction temperature, and the cellulose in the biomass raw material undergoes halogenation, hydrodehalogenation, hydrodeoxygenation, isomerization, and aldol condensation to generate 2,5-hexanedione and 3-methylcyclopentanone;

[0028] (2) the 2,5-hexanedione obtained in step (1) undergoes an aldol condensation reaction in a certain concentration of sodium carbonate aqueous solution, a certain amount of A / B supported noble metal catalyst, and a certain pressure of hydrogen reaction system at a certain reaction temperature to produce 3-methylcyclopentanone;

[0029] (3) The 3-methylcyclopentanone obtained in step (1) and step (2) undergoes an oxidation reaction in a certain amount of H2[WO(O)2(OH)2] and hydrogen peroxide reaction system at a specific temperature to generate 3-methylglutaric acid.

[0030] Furthermore, the biomass raw material described in step (1) includes materials containing cellulose and cellulose derivative compounds, including one or a mixture of two or more of cotton, wood, straw, seaweed, paper, yarn, thread, and cloth; including cellulose homologous materials such as starch; and also including cellulose-based platform compounds such as cellobiose, glucose, fructose, sucrose, lactose, 5-hydroxymethylfurfural, 5-chloromethylfurfural, 2,5-dimethylfuran, and 5-methylfurfural. One or a mixture of two or more.

[0031] Furthermore, the metal salt in the metal salt aqueous solution described in step (1) includes metal chlorides (such as one or more of potassium chloride, calcium chloride, sodium chloride, magnesium chloride, nickel chloride, and chromium chloride), and metal bromides (such as one or more of potassium bromide, calcium bromide, sodium bromide, magnesium bromide, nickel bromide, and chromium bromide).

[0032] Furthermore, the concentration of the metal salt in the metal salt aqueous solution in step (1) is in the range of 10 wt % to 50 wt %.

[0033] Furthermore, the A / B supported precious metal catalyst in step (1) includes one or a mixture of two or more of Pd / C, Pd / Al2O3, Pd / SiO2, Pt / C, Pt / Al2O3, Pt / SiO2, Ru / C, Ru / Al2O3, Ru / SiO2, Rh / C, Rh / Al2O3, Rh / SiO2, Ir / C, Ir / Al2O3, and Ir / SiO2.

[0034] Furthermore, the amount of the A / B supported noble metal catalyst added in step (1) is between 1% and 15% of the mass of the biomass raw material.

[0035] Furthermore, the organic solvent in step (1) includes one or more of methyl isobutyl ketone, tetrahydrofuran, γ-valerolactone, isopropanol, toluene, cyclohexane, dichloromethane, bromobenzene, ethyl acetate, N,N-dimethylformamide, and dimethyl sulfoxide, and the volume ratio of the metal salt aqueous solution to the organic solvent is (1:0.5) to (1:4).

[0036] Furthermore, the pressure range of the hydrogen in step (1) is 0.1 to 10 MPa.

[0037] Furthermore, the reaction temperature in step (1) is in the range of 230 to 300°C.

[0038] Furthermore, the reaction time in step (1) is more than 4 hours.

[0039] Furthermore, in step (1), 5 to 20 mL of a metal salt aqueous solution and 10 to 40 mL of an organic solvent are added to every 50 mg of biomass raw material.

[0040] Furthermore, the concentration of the sodium carbonate aqueous solution in step (2) is in the range of 5 to 20 wt%.

[0041] Furthermore, the A / B supported precious metal catalyst described in step (2) includes one or a mixture of two or more of Pd / C, Pd / Al2O3, Pd / SiO2, Pt / C, Pt / Al2O3, Pt / SiO2, Ru / C, Ru / Al2O3, Ru / SiO2, Rh / C, Rh / Al2O3, Rh / SiO2, Ir / C, Ir / Al2O3, and Ir / SiO2.

[0042] Furthermore, the amount of the A / B supported noble metal catalyst added in step (2) is between 1% and 10% of the mass of the raw material.

[0043] Furthermore, the pressure of the hydrogen in step (2) is 0.5-7 MPa.

[0044] Furthermore, the reaction temperature in step (2) ranges from 90 to 200°C.

[0045] Furthermore, the reaction time in step (2) is greater than 30 minutes.

[0046] Furthermore, in step (2), 1 to 10 mL of sodium carbonate aqueous solution is added to each gram of 2,5-hexanedione.

[0047] Furthermore, the mass ratio of hydrogen peroxide to H2[WO(O)2(OH)2] in step (3) is in the range of (2:1) to (20:1).

[0048] Furthermore, the specific temperature range in step (3) is 85-100°C.

[0049] Furthermore, the reaction time in step (3) is greater than 12 hours.

[0050] Furthermore, in step (3), the mass ratio of 3-methylcyclopentanone to H2[WO(O)2(OH)2] is (1:0.5) to (1:2).

[0051] Furthermore, the H2[WO(O)2(OH)2] is prepared by mixing a certain amount of tungstic acid and hydrogen peroxide at a specific temperature and reacting for a specific time. When the above-mentioned certain amount of tungstic acid and hydrogen peroxide are mixed, the mass ratio of the two is in the range of 1:1 to 1:7; the above-mentioned specific reaction temperature range for preparing H2[WO(O)2(OH)2] is 40 to 70°C. The above-mentioned specific time for preparing H2[WO(O)2(OH)2] is more than 3 hours, until the mixture of tungstic acid and hydrogen peroxide becomes a clear and transparent solution.

[0052] The beneficial effects of the present invention compared with the prior art are as follows:

[0053] 1. The present invention uses widely distributed biomass raw materials as substrates, reduces the consumption of fossil energy, and is conducive to the sustainable development of energy.

[0054] 2. The preparation method of the present invention has mild reaction conditions, high reaction yield, and low raw material price, and provides a new way for preparing glutaric acid and 3-methylglutaric acid.

[0055] 3. The present invention avoids the use of acid solution or alkaline solution, reducing the risk of corrosion of reaction equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention, the drawings of the embodiments are briefly introduced below.

[0057] Figure 1 : Gas chromatogram of cyclopentanone prepared in Example 1;

[0058] Figure 2 : Mass spectrum of cyclopentanone prepared in Example 1;

[0059] Figure 3 : Liquid chromatogram of glutaric acid prepared in Example 139;

[0060] Figure 4 : Mass spectrum of glutaric acid prepared in Example 139;

[0061] Figure 5 : Gas chromatogram of 2,5-hexanedione prepared in Example 258;

[0062] Figure 6 : Mass spectrum of 2,5-hexanedione prepared in Example 258;

[0063] Figure 7 : Gas chromatogram of 3-methylcyclopentanone prepared in Example 320;

[0064] Figure 8 : Mass spectrum of 3-methylcyclopentanone prepared in Example 320;

[0065] Fig. 9 : Liquid chromatogram of 3-methylglutaric acid prepared in Example 337;

[0066] Fig.10 : NMR spectrum of 3-methylglutaric acid prepared in Example 337. DETAILED DESCRIPTION

[0067] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative labor all fall within the protection scope of the present invention.

[0068] The gas chromatography conditions of cyclopentanone, 2,5-hexanedione and 3-methylcyclopentanone in the examples are: HP-5 chromatographic column, TCD detector, column oven temperature: 350° C., injection volume: 0.1 μL.

[0069] The conditions for liquid chromatography of glutaric acid and 3-methylglutaric acid are: XDB-C18 column, UV signal wavelength: 256 nm, mobile phase: methanol: water = 2 / 8 (v / v), flow rate: 0.6 ml / min, injection volume: 0.4 μL.

[0070] The preparation method of H2[WO(O)2(OH)2] used in the embodiment is: tungstic acid and hydrogen peroxide are mixed in a mass ratio of 1:1 and reacted at 50°C until the mixture of tungstic acid and hydrogen peroxide becomes a clear transparent solution (3h or more).

[0071] The mass percentage concentration of hydrogen peroxide used in the embodiment is 30wt%.

[0072] Examples 1 to 8

[0073] 0.5g of each of poplar, pine, straw, seaweed, xylan, xylose, furfural and furfuryl alcohol is added to a 50mL reactor and 50mg Pd / C (Pb loading is 5%) is added; then 10mL 30wt% sodium chloride aqueous solution and 20mL toluene are added to the reactor, hydrogen is filled into the reactor, the pressure is increased to 2MPa, and the reaction is carried out at 240°C for 6h. After the reaction is completed, it is quickly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0074] Table 1: Yield of cyclopentanone under different biomass feedstock conditions

[0075] Example raw material Raw material conversion rate (%) Cyclopentanone yield (%) Example 1 Poplar 91 11 Example 2 Pine 77 8 Example 3 Straw 86 10 Example 4 Seaweed 72 9 Example 5 Xylan >99 41 Example 6 Xylose >99 48 Example 7 Furfural >99 58 Example 8 Furfuryl alcohol >99 56

[0076] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0077] As shown in Table 1, the raw materials in Examples 1 to 8 can all be used to prepare cyclopentanone. The yield of cyclopentanone prepared using raw biomass is 8% or above; the yield of cyclopentanone prepared using hemicellulose-based compounds is greater than 40%.

[0078] Examples 9 to 32

[0079] 0.5 g of xylan and poplar wood powder are added to a 50 mL reactor, and 50 mg of Pd / C catalyst is added, followed by 10 mL of 30 wt% aqueous solution of different metal salts and 20 mL of toluene. After that, hydrogen is filled into the reactor, the pressure is increased to 2 MPa, and the reaction is carried out at 240° C. for 6 hours. After the reaction is completed, the reaction is rapidly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0080] Table 2: Preparation of cyclopentanone from biomass materials under different metal salt aqueous solutions

[0081]

[0082]

[0083] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0084] The data in Table 2 show that different metal salts can be used to prepare cyclopentanone, and different metal salts have a certain influence on the yield of cyclopentanone. Examples 11 and 23 both show that sodium chloride is the preferred metal salt for preparing cyclopentanone.

[0085] Embodiments 33 to 42

[0086] Take 0.5g of xylan and poplar wood powder and add them to a 50mL reactor, add 50mg of Pd / C catalyst, add 10mL of sodium chloride aqueous solution of different concentrations (mass percentage) and 20mL of toluene, then fill the reactor with hydrogen, the pressure reaches 2MPa, and react at 240℃ for 6 hours. After the reaction is completed, quickly cool to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0087] Table 3: Preparation of cyclopentanone from biomass materials under different concentrations of sodium chloride aqueous solution

[0088] Example raw material Sodium chloride concentration (%) Raw material conversion rate (%) Cyclopentanone yield (%) Embodiment 33 Xylan 10 0 0 Embodiment 34 Xylan 20 75 32 Embodiment 35 Xylan 30 >99 41 Embodiment 36 Xylan 40 >99 41 Embodiment 37 Xylan 50 >99 40 Embodiment 38 Poplar wood powder 10 0 0 Embodiment 39 Poplar wood powder 20 45 5 Embodiment 40 Poplar wood powder 30 91 11 Embodiment 41 Poplar wood powder 40 92 12 Embodiment 42 Poplar wood powder 50 92 11

[0089] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0090] Table 3 data show that different concentrations of metal salts can be used to prepare cyclopentanone, and different concentrations of metal salts have a certain influence on the yield of cyclopentanone. It can be seen from the above table that the sodium chloride concentration in the sodium chloride aqueous solution is preferably about 30wt%. The reason is that 30wt% is the saturation concentration of the sodium chloride aqueous solution at room temperature, and when the concentration of the sodium chloride aqueous solution is greater than 30wt%, the conversion rate of the raw material and the yield of the target product do not increase significantly.

[0091] Embodiments 43 to 72

[0092] 0.5 g of xylan and poplar wood powder are added to a 50 mL reactor, and 50 mg of different noble metal catalysts are added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of toluene are added, and then hydrogen is filled into the reactor, the pressure is increased to 2 MPa, and the reaction is carried out at 240° C. for 6 hours. After the reaction is completed, the reaction is quickly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0093] Table 4: Preparation of cyclopentanone from biomass materials under different precious metal catalyst conditions

[0094]

[0095]

[0096] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0097] The data in Table 4 show that the above different noble metal catalysts can all be used to prepare cyclopentanone, and different noble metal catalysts have different effects in the process of preparing cyclopentanone from biomass raw materials. The above results show that both Pd / C and Pt / C catalysts have good activity, but considering the cost of the catalyst, Pd / C catalyst is the most preferred.

[0098] Embodiments 73 to 80

[0099] 0.5 g of xylan and poplar wood powder are added to a 50 mL reactor, and different masses of Pd / C catalysts are added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of toluene are added, and then hydrogen is filled into the reactor, the pressure is increased to 2 MPa, and the reaction is carried out at 240° C. for 6 hours. After the reaction is completed, the reaction is quickly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0100] Table 5: Preparation of cyclopentanone from biomass materials under different noble metal catalyst dosage conditions

[0101] Example raw material Catalyst dosage (%) Raw material conversion rate (%) Cyclopentanone yield (%) Embodiment 73 Xylan 1 >99 25 Embodiment 74 Xylan 5 >99 31 Embodiment 75 Xylan 10 >99 41 Embodiment 76 Xylan 15 >99 42 Embodiment 77 Poplar wood powder 1 85 5 Embodiment 78 Poplar wood powder 5 87 6 Embodiment 79 Poplar wood powder 10 91 11 Embodiment 80 Poplar wood powder 15 92 11

[0102] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants. The amount of catalyst added is 1% to 15% of the mass of the biomass raw material.

[0103] The data in Table 5 show that the above different addition amounts of the noble metal catalyst can all prepare cyclopentanone, and the addition amount of the noble metal catalyst affects the yield of cyclopentanone. As can be seen from the above table, when the addition amount of the catalyst is 10% of the biomass raw material mass, it is the most preferred. The addition of the noble metal catalyst can not only increase the yield of xylan converted to cyclopentanone, but also promote the conversion of poplar wood.

[0104] Embodiments 81 to 100

[0105] 0.5 g of xylan and poplar wood powder are added to a 50 mL reactor, and 50 mg of Pd / C catalyst is added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of different organic solvents are added, and then hydrogen is filled into the reactor, the pressure is increased to 2 MPa, and the reaction is carried out at 240° C. for 6 hours. After the reaction is completed, the reaction is quickly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0106] Table 6: Preparation of cyclopentanone from biomass materials under different organic solvent conditions

[0107] Example raw material Organic solvents Raw material conversion rate (%) Cyclopentanone yield (%) Embodiment 81 Xylan Methyl isobutyl ketone >99 40 Embodiment 82 Xylan Tetrahydrofuran >99 35 Embodiment 83 Xylan γ-Valerolactone >99 32 Embodiment 84 Xylan Isopropyl alcohol >99 27 Embodiment 85 Xylan Toluene >99 41 Embodiment 86 Xylan Cyclohexane >99 30 Embodiment 87 Xylan Dichloromethane >99 39 Embodiment 88 Xylan Bromobenzene >99 40 Embodiment 89 Xylan Ethyl acetate >99 35 Embodiment 90 Xylan Dimethyl sulfoxide >99 29 Embodiment 91 Poplar wood powder Methyl isobutyl ketone 87 9 Embodiment 92 Poplar wood powder Tetrahydrofuran 88 10 Embodiment 93 Poplar wood powder γ-Valerolactone 75 5 Embodiment 94 Poplar wood powder Isopropyl alcohol 77 6 Embodiment 95 Poplar wood powder Toluene 91 11 Embodiment 96 Poplar wood powder Cyclohexane 95 9 Embodiment 97 Poplar wood powder Dichloromethane 96 10 Embodiment 98 Poplar wood powder Bromobenzene 93 10 Embodiment 99 Poplar wood powder Ethyl acetate 81 7 Embodiment 100 Poplar wood powder Dimethyl sulfoxide 84 8

[0108] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0109] The data in Table 6 show that the above-mentioned different types of organic solvents can all prepare cyclopentanone, and the type of organic solvent affects the yield of cyclopentanone. As can be seen from the above table, toluene is the most preferred among the above-mentioned organic solvents.

[0110] Examples 101 to 106

[0111] 0.5 g of xylan and poplar wood powder are added to a 50 mL reactor, and 50 mg of Pd / C catalyst is added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of toluene are added, and then hydrogen is filled into the reactor at pressures of 1, 5, and 7 MPa, respectively, and the reaction is carried out at 240° C. for 6 hours. After the reaction is completed, the reaction is quickly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0112] Table 7: Preparation of cyclopentanone from biomass materials under different hydrogen pressure conditions

[0113]

[0114]

[0115] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0116] The data in Table 7 show that cyclopentanone can be prepared under the above different hydrogen pressures, and the hydrogen pressure has little effect on the yield of cyclopentanone.

[0117] Examples 107 to 122

[0118] Take 0.5g of xylan and poplar powder respectively and add them into a 50mL reactor, add 50mg of Pd / C catalyst, add 10mL of 30wt% sodium chloride aqueous solution and 20mL of toluene, then fill the reactor with hydrogen, the pressure is 2MPa, and react for 6 hours at different reaction temperatures. After the reaction is completed, quickly cool to room temperature, and separate the organic phase to obtain the target product cyclopentanone. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0119] Table 8: Preparation of cyclopentanone from biomass materials under different reaction temperature conditions

[0120] Example raw material Reaction temperature (℃) Raw material conversion rate (%) Cyclopentanone(%) Embodiment 107 Xylan 150 87 56 Embodiment 108 Xylan 170 95 55 Embodiment 109 Xylan 200 >99 50 Embodiment 110 Xylan 220 >99 45 Embodiment 111 Xylan 240 >99 41 Embodiment 112 Xylan 260 >99 37 Embodiment 113 Xylan 280 >99 33 Embodiment 114 Xylan 300 >99 30 Embodiment 115 Poplar wood powder 150 0 0 Embodiment 116 Poplar wood powder 170 12 0 Embodiment 117 Poplar wood powder 200 36 6 Embodiment 118 Poplar wood powder 220 79 10 Embodiment 119 Poplar wood powder 240 91 11 Embodiment 120 Poplar wood powder 260 95 10 Embodiment 121 Poplar wood powder 280 >99 9 Embodiment 122 Poplar wood powder 300 >99 9

[0121] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0122] The data in Table 8 show that cyclopentanone can be prepared at the above different reaction temperatures, and the reaction temperature affects the yield of cyclopentanone. As can be seen from the above table, the more suitable temperature range for preparing cyclopentanone is 150-260°C, and the preparation of cyclopentanone is not suitable for being carried out at too high a temperature.

[0123] Embodiments 123 to 134

[0124] 0.5 g of xylan and poplar powder are added to a 50 mL reactor, and 50 mg of Pd / C catalyst is added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of different organic solvents are added, hydrogen is filled into the reactor, the pressure is 2 MPa, and the reaction is carried out at 240° C. for 2 to 24 hours. After the reaction is completed, the reaction is quickly cooled to room temperature, and the target product cyclopentanone can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the cyclopentanone content is detected by gas chromatography.

[0125] Table 9: Preparation of cyclopentanone from biomass materials under different reaction time conditions

[0126] Example raw material Reaction time (h) Raw material conversion rate (%) Cyclopentanone(%) Embodiment 123 Xylan 2 77 26 Embodiment 124 Xylan 3 90 35 Embodiment 125 Xylan 4 96 37 Embodiment 126 Xylan 6 >99 41 Embodiment 127 Xylan 12 >99 40 Embodiment 128 Xylan 24 >99 42 Embodiment 129 Poplar wood powder 2 17 0 Embodiment 130 Poplar wood powder 3 50 6 Embodiment 131 Poplar wood powder 4 73 8 Embodiment 132 Poplar wood powder 6 91 11 Embodiment 133 Poplar wood powder 12 91 10 Embodiment 134 Poplar wood powder 24 91 11

[0127] Note: The cyclopentanone yield in the above table is calculated based on the mass of pentose in the reactants.

[0128] The data in Table 9 show that cyclopentanone can be prepared under the above different reaction times, and the reaction time will also affect the yield of cyclopentanone, and the suitable reaction time is 4 to 24 hours. The data in the above table show that the reaction time of 6 hours is the most preferred.

[0129] Embodiments 135 to 140

[0130] A certain amount of H2[WO(O)2(OH)2], hydrogen peroxide (HO) and 4g cyclopentanone were added to a round-bottom flask. The amounts of H2[WO(O)2(OH)2] and hydrogen peroxide added were 4g, 8g; 4g, 12g; 4g, 20g; 4g, 40g; 4g, 60g; 4g, 80g, respectively, that is, the mass ratios of H2[WO(O)2(OH)2] and hydrogen peroxide (HW / HO) were 1:2, 1:3, 1:5, 1:10, 1:15, 1:20, respectively. After the top of the round-bottom flask was connected to a circulating water condenser, it was placed in an oil bath and reacted at 95°C for 20h. After the reaction was completed, the temperature was quickly lowered, and the sample was recrystallized in a 0°C environment to obtain the target product, glutaric acid. The structure of glutaric acid was determined by nuclear magnetic resonance spectroscopy, and the yield of glutaric acid was quantified by liquid chromatography.

[0131] Table 10: Yield of glutaric acid of cyclopentanone under different HW / HO conditions

[0132] Example raw material HW / HO Cyclopentanone conversion rate (%) Glutaric acid yield (%) Embodiment 135 Cyclopentanone 1：2 >99 75 Embodiment 136 Cyclopentanone 1：3 >99 92 Embodiment 137 Cyclopentanone 1：5 >99 90 Embodiment 138 Cyclopentanone 1：10 >99 91 Embodiment 139 Cyclopentanone 1：15 >99 93 Embodiment 140 Cyclopentanone 1：20 >99 91

[0133] The data in Table 10 show that the above-mentioned different feed ratios of HW / HO can promote cyclopentanone to produce glutaric acid. However, different values ​​of HW / HO will affect the yield of glutaric acid to a certain extent, and the preferred HW / HO ratio is 1:3 to 1:20.

[0134] Embodiments 141 to 144

[0135] 4g of H2[WO(O)2(OH)2], 12g of hydrogen peroxide and 4g of cyclopentanone were added to a round-bottom flask. After the top of the round-bottom flask was connected to a circulating water condenser, it was placed in an oil bath and reacted at 85, 90, 95 and 100°C for 20h. After the reaction was completed, the temperature was rapidly lowered and the sample was recrystallized in a zero-degree environment to obtain the target product, glutaric acid. The structure of glutaric acid was determined by nuclear magnetic resonance spectroscopy, and the yield of glutaric acid was quantified by liquid chromatography.

[0136] Table 11: Yield of glutaric acid of cyclopentanone under different reaction temperature conditions

[0137] Example raw material Reaction temperature (℃) Cyclopentanone conversion rate (%) Glutaric acid yield (%) Embodiment 141 Cyclopentanone 85 77 50 Embodiment 142 Cyclopentanone 90 91 87 Embodiment 143 Cyclopentanone 95 >99 92 Embodiment 144 Cyclopentanone 100 >99 90

[0138] The data in Table 11 show that the above reaction temperatures can promote cyclopentanone to produce glutaric acid. From Example 143, it can be seen that the optimal reaction temperature is 95°C.

[0139] Embodiments 145 to 149

[0140] 4g of H2[WO(O)2(OH)2], 12g of hydrogen peroxide and 4g of cyclopentanone were added to a round-bottom flask, and a circulating water condenser was connected to the top of the round-bottom flask. Then, the flask was placed in an oil bath and reacted at 95°C for 5, 10, 15, 20, and 40 hours, respectively. After the reaction was completed, the temperature was rapidly lowered, and the sample was recrystallized in a zero-degree environment to obtain the target product, glutaric acid. The structure of glutaric acid was determined by nuclear magnetic resonance spectroscopy, and the yield of glutaric acid was quantified by liquid chromatography.

[0141] Table 12: Yield of glutaric acid under different reaction time conditions of cyclopentanone

[0142] Example raw material Reaction time (h) Cyclopentanone conversion rate (%) Glutaric acid yield (%) Embodiment 145 Cyclopentanone 5 80 50 Embodiment 146 Cyclopentanone 10 >99 92 Embodiment 147 Cyclopentanone 15 >99 92 Embodiment 148 Cyclopentanone 20 >99 93 Embodiment 149 Cyclopentanone 40 >99 92

[0143] The data in Table 12 show that the above reaction times can promote cyclopentanone to produce glutaric acid. From Examples 145-149, it can be seen that the optimal reaction time should be 12 h.

[0144] Embodiments 150 to 157

[0145] 0.5g of each of poplar, pine, straw, seaweed, microcrystalline cellulose, glucose, 5-hydroxymethylfurfural, and 2,5-dimethylfuran were added to a 50mL reactor and 50mg Pd / C (Pb loading was 5%) was added; then 10mL 30wt% sodium chloride aqueous solution and 20mL toluene were added to the reactor, hydrogen was filled into the reactor, the pressure was increased to 2MPa, and the reaction was carried out at 240°C for 6h. After the reaction was completed, it was quickly cooled to room temperature, and the target product was obtained by separation of the organic phase. The type of the target product was determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone was detected by gas chromatography.

[0146] Table 13: Yields of 3-methylcyclopentanone and 2,5-hexanedione under different biomass raw material conditions

[0147]

[0148] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0149] It can be seen from Table 13 that the raw materials in the above examples can all be used to prepare 3-methylcyclopentanone and hexanedione. When a cellulose-based platform compound is used as a raw material, the total yield of 3-methylcyclopentanone and hexanedione can reach up to 90%.

[0150] Embodiments 158 to 181

[0151] Take 0.5g of glucose and poplar wood powder and add them to a 50mL reactor, add 50mg of Pd / C catalyst, then add 10mL of 30wt% aqueous solution of different metal salts and 20mL of toluene, then fill the reactor with hydrogen, the pressure reaches 2MPa, and react at 240℃ for 6 hours. After the reaction is completed, quickly cool to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0152] Table 14: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different conditions of aqueous metal salt solutions

[0153]

[0154]

[0155] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0156] The data in Table 14 show that different metal salts can be used to prepare 3-methylcyclopentanone and hexanedione. Different metal salts have a certain influence on the yield of 3-methylcyclopentanone and hexanedione, and sodium chloride is preferred as the metal salt.

[0157] Embodiments 180 to 191

[0158] Take 0.5g of glucose and poplar powder and add them to a 50mL reactor, add 50mg of Pd / C catalyst, add 10mL of sodium chloride aqueous solution of different concentrations (mass percentage) and 20mL of toluene, then fill the reactor with hydrogen, the pressure reaches 2MPa, and react at 240℃ for 6 hours. After the reaction is completed, quickly cool to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0159] Table 15: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different concentrations of sodium chloride aqueous solution

[0160]

[0161] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0162] The data in Table 15 show that different salt concentrations can be used to prepare 3-methylcyclopentanone and hexanedione. Different metal salt concentrations have a certain effect on the yields of 3-methylcyclopentanone and hexanedione, preferably 20 to 50 wt%.

[0163] Embodiments 192 to 221

[0164] Take 0.5g of glucose and poplar powder and add them to a 50mL reactor, add 50mg of different precious metal catalysts, add 10mL of 30wt% sodium chloride aqueous solution and 20mL of toluene, then fill the reactor with hydrogen, the pressure reaches 2MPa, and react at 240℃ for 6 hours. After the reaction is completed, quickly cool to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0165] Table 16: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different precious metal catalyst conditions

[0166]

[0167] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0168] The data in Table 16 show that the above different noble metal catalysts can be used to prepare 2,5-hexanedione and 3-methylcyclopentanone, and different noble metal catalysts have different effects in the process of preparing 3-methylcyclopentanone and 2,5-hexanedione from biomass raw materials. And the data show that Pd / C is the most preferred.

[0169] Embodiments 222 to 229

[0170] 0.5 g of glucose and poplar powder were added to a 50 mL reactor, and different masses of Pd / C catalysts were added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of toluene were added, and then hydrogen was filled into the reactor, the pressure was increased to 2 MPa, and the reaction was carried out at 240 ° C for 6 hours. After the reaction was completed, it was quickly cooled to room temperature, and the target product was obtained by organic phase separation. The type of the target product was determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone was detected by gas chromatography.

[0171] Table 17: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different noble metal catalyst dosage conditions

[0172]

[0173] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants. The amount of catalyst added is 1% to 15% of the mass of the biomass raw material.

[0174] The data in Table 17 show that the above different amounts of noble metal catalysts can prepare 3-methylcyclopentanone and 2,5-hexanedione, and the amount of noble metal catalyst added affects the yield of 3-methylcyclopentanone and 2,5-hexanedione. It can be seen from the above table that when the amount of catalyst added is 10% of the weight of the biomass raw material, it is the most preferred. And the addition of noble metal catalysts can promote the conversion of poplar wood.

[0175] Embodiments 230 to 249

[0176] Take 0.5g of glucose and poplar wood powder and add them to a 50mL reactor, add 50mg of Pd / C catalyst, add 10mL of 30wt% sodium chloride aqueous solution and 20mL of different organic solvents, then fill the reactor with hydrogen, the pressure reaches 2MPa, and react at 240℃ for 6 hours. After the reaction is completed, quickly cool to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0177] Table 18: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different organic solvent conditions

[0178]

[0179] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0180] The data in Table 18 show that the above different amounts of organic solvents can prepare 3-methylcyclopentanone and 2,5-hexanedione, and the type of organic solvent affects the yield of 3-methylcyclopentanone and 2,5-hexanedione. As can be seen from the above table, the preferred organic solvents are toluene, dichloromethane, bromobenzene and cyclohexane.

[0181] Embodiments 250 to 255

[0182] Take 0.5g of glucose and poplar powder respectively and add them into a 50mL reactor, add 50mg of Pd / C catalyst, add 10mL of 30wt% sodium chloride aqueous solution and 20mL of toluene, then fill the reactor with hydrogen, the pressure is 1, 5, 7MPa respectively, and react at 240℃ for 6 hours. After the reaction is completed, it is quickly cooled to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0183] Table 19: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different hydrogen pressure conditions

[0184]

[0185]

[0186] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0187] The data in Table 19 show that 3-methylcyclopentanone and 2,5-hexanedione can be prepared under the above different hydrogen pressures. The hydrogen pressure has little effect on the yield of 3-methylcyclopentanone and 2,5-hexanedione, and is preferably 2 to 7 MPa.

[0188] Embodiments 256 to 271

[0189] Take 0.5g of glucose and poplar wood powder and add them to a 50mL reactor, add 50mg of Pd / C catalyst, add 10mL of 30wt% sodium chloride aqueous solution and 20mL of toluene, then fill the reactor with hydrogen, the pressure is 2MPa, and react for 6 hours at different reaction temperatures. After the reaction is completed, quickly cool to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0190] Table 20: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different reaction temperature conditions

[0191]

[0192] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0193] The data in Table 20 show that 2,5-hexanedione and 3-methylcyclopentanone can be prepared at the above different reaction temperatures, and the reaction temperature affects the yield of 3-methylcyclopentanone and 2,5-hexanedione. It can be seen from the above table that the preparation of 3-methylcyclopentanone and 2,5-hexanedione is not suitable for being carried out at too high a temperature, preferably 220-300°C.

[0194] Embodiments 272 to 283

[0195] 0.5 g of glucose and poplar wood powder are added to a 50 mL reactor, and 50 mg of Pd / C catalyst is added, 10 mL of 30 wt% sodium chloride aqueous solution and 20 mL of different organic solvents are added, hydrogen is filled into the reactor, the pressure is 2 MPa, and the reaction is carried out at 240° C. for 2-24 hours. After the reaction is completed, it is quickly cooled to room temperature, and the target product can be obtained by organic phase separation. The type of the target product is determined by gas chromatography-mass spectrometry, and the content of 2,5-hexanedione and 3-methylcyclopentanone is detected by gas chromatography.

[0196] Table 21: Preparation of 2,5-hexanedione and 3-methylcyclopentanone from biomass materials under different reaction time conditions

[0197]

[0198] Note: The yields of 3-methylcyclopentanone and 2,5-hexanedione in the above table are calculated based on the mass of hexose in the reactants.

[0199] The data in Table 21 show that 2,5-hexanedione and 3-methylcyclopentanone can be prepared at the above different reaction times, and the reaction time will affect the yield of 3-methylcyclopentanone and 2,5-hexanedione. The results in the above table show that the reaction time is preferably 4 to 24 hours.

[0200] Embodiments 284 to 287

[0201] 5 g of 2,5-hexanedione, 10 mL of Na2CO3 aqueous solution of different concentrations, and 40 mg of Pd / C were added to a reactor, and 8 MPa of hydrogen was filled into the reactor. The reaction was carried out at 120°C for 3 hours. After separation of the organic phase, 3-methylcyclopentanone was obtained. The type of the target product was determined by gas chromatography-mass spectrometry, and the content of 3-methylcyclopentanone was detected by gas chromatography.

[0202] Table 22: Yield of 3-methylcyclopentanone with 2,5-hexanedione in different Na2CO3 aqueous solution concentrations

[0203]

[0204]

[0205] The data in Table 22 show that the above-mentioned different Na2CO3 aqueous solution concentrations can all prepare 3-methylcyclopentanone. Different Na2CO3 aqueous solutions will affect the yield of 3-methylcyclopentanone. The preferred concentration of the Na2CO3 aqueous solution is 10-20wt%.

[0206] Embodiments 288 to 301

[0207] 5 g of 2,5-hexanedione, 10 mL of 15% Na2CO3 aqueous solution, and 40 mg of different noble metal catalysts were added to a reactor. 8 Mpa of hydrogen was filled into the reactor and reacted at 120°C for three hours. After separation of the organic phase, 3-methylcyclopentanone was obtained. The target product was determined by gas chromatography-mass spectrometry, and the content of 3-methylcyclopentanone was detected by gas chromatography.

[0208] Table 23: Yield of 3-methylcyclopentanone with 2,5-hexanedione under different precious metal catalyst conditions

[0209]

[0210] The data in Table 23 show that the above-mentioned different precious metal catalysts can all prepare 3-methylcyclopentanone. Different precious metal catalysts will affect the yield of 3-methylcyclopentanone, and Pd / C and Pt / C are preferred.

[0211] Embodiments 302 to 306

[0212] 5g of 2,5-hexanedione, 10mL of 15% Na2CO3 aqueous solution, and 40mg of Pd / C (respectively 1%, 3%, 5%, 7%, and 10% of the raw material mass) were added to a reactor. 8Mpa of hydrogen was filled into the reactor and reacted at 120°C for three hours. After the organic phase was separated, 3-methylcyclopentanone was obtained. The target product type was determined by gas chromatography-mass spectrometry, and the content of 3-methylcyclopentanone was detected by gas chromatography.

[0213] Table 24: 3-methylcyclopentanone yield of 2,5-hexanedione under catalyst addition conditions

[0214]

[0215] The data in Table 24 show that the addition amounts of the above-mentioned different precious metal catalysts can all prepare 3-methylcyclopentanone. The addition amounts of different precious metal catalysts will affect the yield of 3-methylcyclopentanone, and the addition amount is preferably 5 to 10%.

[0216] Embodiments 307 to 317

[0217] 5g of 2,5-hexanedione, 10mL of 15% Na2CO3 aqueous solution, and different masses of Pd / C were added to the reactor. Hydrogen gas of different pressures (0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10Mpa) was injected into the reactor and reacted at 120°C for three hours. 3-methylcyclopentanone was obtained after separation of the organic phase. The target product was determined by gas chromatography-mass spectrometry, and the content of 3-methylcyclopentanone was detected by gas chromatography.

[0218] Table 25: 3-Methylcyclopentanone yield under different hydrogen addition conditions of 2,5-hexanedione

[0219]

[0220] The data in Table 25 show that the above different amounts of hydrogen added can all prepare 3-methylcyclopentanone. Different amounts of hydrogen added will affect the yield of 3-methylcyclopentanone. The preferred amount of hydrogen added is 4 to 10 MPa.

[0221] Embodiments 318 to 326

[0222] 5g of 2,5-hexanedione, 10mL of 15% Na2CO3 aqueous solution, and different masses of Pd / C were added to a reactor. 8Mpa of hydrogen was injected into the reactor and reacted at different temperatures for three hours. After separation of the organic phase, 3-methylcyclopentanone was obtained. The target product was determined by gas chromatography-mass spectrometry, and the content of 3-methylcyclopentanone was detected by gas chromatography.

[0223] Table 26: Yield of 3-methylcyclopentanone under different reaction temperature conditions of 2,5-hexanedione

[0224]

[0225] The data in Table 26 show that 3-methylcyclopentanone can be prepared at the above different temperatures. Different temperatures will affect the yield of 3-methylcyclopentanone, and the reaction temperature is preferably 90-140°C.

[0226] Embodiments 327 to 332

[0227] 5 g of 2,5-hexanedione, 10 mL of 15% Na2CO3 aqueous solution, and 40 mg of Pd / C were added to a reactor. 8 MPa of hydrogen was injected into the reactor and the reaction was carried out at 120°C for (0.5, 1, 2, 4, 12, 24) hours. After separation of the organic phase, 3-methylcyclopentanone was obtained. The target product was determined by gas chromatography-mass spectrometry, and the content of 3-methylcyclopentanone was detected by gas chromatography.

[0228] Table 27: Yield of 3-methylcyclopentanone under different reaction time conditions of 2,5-hexanedione

[0229]

[0230] The data in Table 27 show that 3-methylcyclopentanone can be prepared at the above different reaction times, preferably 1 to 12 hours.

[0231] Embodiments 333 to 338

[0232] 4g of H2[WO(O)2(OH)2](HW), a certain amount of hydrogen peroxide (HO) (the mass ratio of HO to H2[WO(O)2(OH)2] was 2:1, 4:1, 8:1, 12:1, 16:1, 20:1 respectively) and 4g of 3-methylcyclopentanone were added to a round-bottom flask, and the top of the round-bottom flask was connected to a circulating water condenser, and then placed in an oil bath pot and reacted at 95°C for 20h. After the reaction was completed, the temperature was quickly lowered, and the sample was recrystallized in a 0°C environment to obtain the target product 3-methylglutaric acid. The structure of 3-methylglutaric acid was determined by nuclear magnetic resonance spectroscopy, and the yield of 3-methylglutaric acid was quantified by liquid chromatography.

[0233] Table 28: Preparation of 3-methylglutaric acid from 3-methylcyclopentanone under different HW / HO conditions

[0234]

[0235] The data in Table 28 show that the above different HO / HW can all prepare 3-methylcyclopentanone, preferably 4:1 to 20:1.

[0236] Embodiments 339 to 342

[0237] Take 4g of H2[WO(O)2(OH)2](HW), 48g of hydrogen peroxide (HO) and 4g of 3-methylcyclopentanone and add them to a round-bottom flask. After connecting the top of the round-bottom flask to a circulating water condenser, put it in an oil bath and react at 85, 90, 95, and 100°C for 20h. After the reaction is completed, the temperature is quickly lowered and the sample is recrystallized in a zero-degree environment to obtain the target product 3-methylglutaric acid. The structure of 3-methylglutaric acid is determined by nuclear magnetic resonance spectroscopy, and the yield of 3-methylglutaric acid is quantified by liquid chromatography.

[0238] Table 29: Yield of 3-methylglutaric acid of cyclopentanone under different reaction temperature conditions

[0239]

[0240] The data in Table 29 show that the above different reaction temperatures can all prepare 3-methylcyclopentanone. Different reaction temperatures have an effect on the yield of 3-methylglutaric acid.

[0241] Embodiments 343 to 347

[0242] Take 4g of H2[WO(O)2(OH)2](HW), 48g of hydrogen peroxide (HO) and 4g of 3-methylcyclopentanone and add them to a round-bottom flask. After connecting the top of the round-bottom flask to a circulating water condenser, put it in an oil bath and react at 100°C for 12, 16, 18, 24, and 48h respectively. After the reaction is completed, the temperature is quickly lowered, and the sample is recrystallized in a zero-degree environment to obtain the target product 3-methylglutaric acid. The structure of 3-methylglutaric acid is determined by nuclear magnetic resonance spectroscopy, and the yield of 3-methylglutaric acid is quantified by liquid chromatography.

[0243] Table 30: 3-Methylglutaric acid yield of cyclopentanone under different reaction time conditions

[0244]

[0245] The data in Table 30 show that the above different reaction times can all prepare 3-methylcyclopentanone, and the preferred reaction time is 18 to 24 hours.

Claims

1. A method for preparing 3-methylglutaric acid from biomass raw materials, It is characterized in that The following steps are involved: (1) The biomass raw material reacts in a reaction system of a certain concentration of metal salt aqueous solution, a certain amount of A / B supported noble metal catalyst, an organic solvent and a certain pressure of hydrogen at a specific reaction temperature, and the cellulose in the biomass raw material reacts to produce 2,5-hexanedione and 3-methylcyclopentanone; (2) the 2,5-hexanedione obtained in step (1) undergoes an aldol condensation reaction in a certain concentration of sodium carbonate aqueous solution, a certain amount of A / B supported noble metal catalyst, and a certain pressure of hydrogen reaction system at a certain reaction temperature to produce 3-methylcyclopentanone; (3) The 3-methylcyclopentanone obtained in step (1) and step (2) is reacted with H 2 [WO(O) 2 (OH) 2 ] and hydrogen peroxide reaction system, at a specific temperature, an oxidation reaction occurs to generate 3-methylglutaric acid; The biomass raw material described in step (1) is selected from cellulose derivative compounds, cellulose homologous substances and cellulose-based platform compounds, the cellulose derivative compounds are selected from cotton, wood, straw, seaweed, paper, yarn, thread, cloth; the cellulose homologous substances are selected from starch; the cellulose-based platform compounds are selected from cellobiose, glucose, fructose, sucrose, lactose, 5-hydroxymethylfurfural, 5-chloromethylfurfural, 2, 5-dimethylfuran, 5-methylfurfural; the metal salt in the metal salt aqueous solution is a metal chloride and a metal bromide, the metal chloride is selected from potassium chloride, calcium chloride, sodium chloride, magnesium chloride, chromium chloride, and the metal bromide is selected from potassium bromide, calcium bromide, sodium bromide, nickel bromide, chromium bromide; the metal salt concentration in the metal salt aqueous solution ranges from 10 wt% to 50 wt%; the A / B supported noble metal catalyst is Pd / C, Pd / Al 2 O 3 、Pd / SiO 2 、Pt / C、Pt / Al 2 O 3 、Pt / SiO 2 、Ru / C、Ru / Al 2 O 3 、Ru / SiO 2 , Rh / C, Rh / Al 2 O 3 、Rh / SiO 2 、Ir / C、Ir / Al 2 O 3 、Ir / SiO 2 one or a mixture of two or more of the above; the amount of the A / B supported noble metal catalyst added is between 1% and 15% of the mass of the biomass raw material; the organic solvent is selected from methyl isobutyl ketone, tetrahydrofuran, γ-valerolactone, isopropanol, toluene, cyclohexane, dichloromethane, bromobenzene, ethyl acetate, N,N-dimethylformamide, dimethyl sulfoxide; the volume ratio of the metal salt aqueous solution to the organic solvent is (1:0.5) to (1:4); the pressure range of the hydrogen is 0.1 to 10 MPa; the reaction temperature is 230 to 300°C; the reaction time is more than 4 hours; The concentration of the sodium carbonate aqueous solution in step (2) is in the range of 5 to 20 wt %; the A / B supported noble metal catalyst is Pd / C, Pd / Al 2 O 3 、Pd / SiO 2 、Pt / C、Pt / Al 2 O 3 、Pt / SiO 2 、Ru / C、Ru / Al 2 O 3 、Ru / SiO 2 , Rh / C, Rh / Al 2 O 3 、Rh / SiO 2 、Ir / C、Ir / Al 2 O 3 、Ir / SiO 2 One or a mixture of two or more thereof; the pressure of the hydrogen is 0.5-7 Mpa; the reaction temperature range is 90 ~ 200 ° C; the reaction time range is more than 30 minutes; The specific temperature range in step (3) is 85 ~ 100 ° C; the reaction time is more than 12 hours; The H 2 [WO(O) 2 (OH) 2 The preparation process of ] is to mix tungstic acid and hydrogen peroxide in a mass ratio of 1:1~1:7 and react at 40~70℃ until the mixture of tungstic acid and hydrogen peroxide becomes a clear and transparent solution.

2. The method according to claim 1, It is characterized in that In step (1), 5 to 20 mL of a metal salt aqueous solution and 10 to 40 mL of an organic solvent are added to every 50 mg of biomass raw material.

3. The method according to claim 1, It is characterized in that In step (2), 1 to 10 mL of sodium carbonate aqueous solution is added to each gram of 2,5-hexanedione; the amount of the A / B supported noble metal catalyst added is between 1% and 10% of the mass of 2,5-hexanedione.

4. The method according to claim 1, It is characterized in that The hydrogen peroxide and H 2 [WO(O) 2 (OH) 2 ] is in a mass ratio of (2:1) to (20:1); 3-methylcyclopentanone and H 2 [WO(O) 2 (OH) 2 ] is in the range of (1:0.5) to (1:2).

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