Method for preparing gamma-valerolactone by hydrogenolysis of D-xylose through one-pot method

Abstract

The invention discloses a method for preparing gamma-valerolactone by one-pot hydrogenolysis of D-xylose, which is characterized in that isopropyl alcohol is used as a reaction solvent, Pt / H beta is used as a catalyst, and the gamma-valerolactone is prepared by one-pot hydrogenolysis of D-xylose as a raw material in a high-pressure reaction kettle in a hydrogen atmosphere. The preparation process is simple, the raw materials are easy to obtain, the reaction time is short, the reaction process is environment-friendly and pollution-free, the catalytic system is relatively simple, the raw material conversion rate can reach 100%, and the highest gamma-valerolactone yield can reach 52.1%. And the Pt / H beta has good stability, can be recycled after being simply filtered and dried, can save resources and reduce the cost, and has important application value.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of gamma-valerolactone, and specifically relates to a method for preparing gamma-valerolactone by one-pot hydrogenolysis using D-xylose as a raw material. Background Art

[0002] Lignocellulose is a promising biomass feedstock due to its natural abundance and is generally considered more viable than first-generation biofuel feedstocks because it does not compete with food crops for arable land. Therefore, the development of appropriate technologies and infrastructure that can effectively utilize lignocellulosic feedstocks is of great benefit to society from both social and economic perspectives. Gamma-valerolactone (GVL) derived from lignocellulose has the favorable properties of a green solvent and fuel additive, and is also a precursor for the production of liquid alkanes and high-value biopolymers. Therefore, as a versatile biomass-derived platform chemical, GVL has received increasing attention over the past period of time.

[0003] GVL is generally produced by converting monosaccharides released by hydrolysis of lignocellulose into levulinic acid (LA) using an acid catalyst, which is then hydrogenated to GVL using hydrogen and a metal catalyst. It is reported that although this method can provide a higher yield of GVL, it also has some important disadvantages: mineral acid is used in the acid catalysis step; the reaction is a multi-step reaction; and the production cost is relatively high.

[0004] At present, the one-pot hydrogenolysis of D-xylose using different catalysts can synthesize various high value-added platform compounds. For example, Deng et al. used a bifunctional Cu / SBA-15-SO3H catalyst to catalyze the conversion of D-xylose into furfuryl alcohol in a water / n-butanol biphasic solvent for 6 hours at 140°C and 4MPa H2 under the optimized conditions, with a yield of 62.6% (Chinese J. Catal., 2020, 41, 404–414). Canhaci et al. studied a platinum catalyst supported on an ordered mesoporous SBA-15 with -SO3H groups (Pt / SBA-15-SO3H )The process of converting D-xylose into furfuryl alcohol in one step was described above. Under the optimized conditions of 130°C and 3MPaH2 for 6h, the yield of furfuryl alcohol reached 54% (Appl. Catal. B-Environ., 2017, 207, 279-285). Insyani et al. introduced the one-pot cascade conversion of D-xylose into tetrahydrofurfuryl alcohol over RuO2-Ru (RuO2-Ru / Hβ) catalyst supported on Hβ zeolite. In tetrahydrofuran, the initial H2 pressure was 3MPa. After reacting at 180°C for 1h, D-xylose was almost completely converted, and the yield of tetrahydrofurfuryl alcohol reached 61.8% (Appl. Catal. B-Environ., 2021, 291, 120120). Liang et al. prepared a carbon-nitrogen-coated metal Co catalyst (Co@NC) for catalytic direct conversion of D-xylose. The yield of 1,2-pentanediol was 27.4% after 3 hours of reaction at 200°C and 3.0MPa H2 (J. Fuel Chem. Technol., 2021, 49, 1898–1910). In addition, in the research published by this laboratory, with the assistance of organic acid, a mesoporous nitrogen-carbon supported platinum catalyst (Pt / NC) was used to achieve a one-pot catalytic conversion of D-xylose to 1,2-pentanediol. In the presence of 2.5Pt / NC600 catalyst and propionic acid co-catalyst, D-xylose was reacted in water at 200°C and 3MPa H2 pressure for 8 hours, and the yield of 1,2-pentanediol reached 49.3% (ChemSusChem, 2024, e202401109).

[0005] The above catalyst uses H2 as a hydrogen donor to catalyze the cascade conversion of D-xylose to various high-value-added platform compounds, showing good prospects. Therefore, it is of great research value to provide a method for preparing GVL by efficient hydrogenolysis of D-xylose with simple synthesis, environmental friendliness and high yield. Summary of the invention

[0006] In order to solve the problem of complex process of preparing γ-valerolactone by hydrogenolysis of D-xylose as raw material in the prior art, the present invention provides a method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose with high catalytic activity, easy raw materials, simple process and environmental friendliness.

[0007] The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose provided by the present invention comprises the following steps: placing D-xylose and isopropanol in a high-pressure reactor, adding a Pt / Hβ catalyst, stirring and reacting for 8 to 20 hours in a hydrogen atmosphere, a pressure of 1.5 to 4.5 MPa, and a temperature of 130 to 210° C., cooling to room temperature after the reaction is completed, and centrifuging and separating the catalyst to obtain γ-valerolactone.

[0008] In the method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose, the mass ratio of D-xylose to Pt / Hβ catalyst is 0.5-4:1, preferably the mass ratio of D-xylose to Pt / Hβ catalyst is 1.5-2.5:1.

[0009] In the above method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose, the reaction is preferably stirred for 12 to 16 hours under a hydrogen atmosphere, a pressure of 2.5 to 3.5 MPa, and a temperature of 170 to 190°C.

[0010] The preparation method of the above-mentioned Pt / Hβ catalyst is as follows: commercially available Hβ zeolite is calcined at 500-600°C for 3-5 hours in an air atmosphere to obtain activated Hβ zeolite; then, the activated Hβ zeolite is used as a carrier, H2PtCl6 is loaded by an impregnation method, and then calcined at 350-450°C for 3-5 hours in an air atmosphere, and finally reduced at 200-400°C for 1-3 hours in a mixed atmosphere of hydrogen and argon to obtain a Pt / Hβ catalyst; based on the mass of the catalyst as 100%, the Pt loading amount in the Pt / Hβ catalyst is 0.5%-5%.

[0011] In the preparation method of the Pt / Hβ catalyst, commercially available Hβ zeolite is preferably calcined at 550° C. for 4 hours in an air atmosphere to obtain activated Hβ zeolite.

[0012] In the preparation method of the above-mentioned Pt / Hβ catalyst, it is preferred to use activated Hβ zeolite as a carrier, load H2PtCl6 by an impregnation method, and then calcine at 400°C for 4 hours in an air atmosphere.

[0013] In the preparation method of the Pt / Hβ catalyst, the heating rate of the calcination is preferably 3 to 5°C / min.

[0014] In the preparation method of the Pt / Hβ catalyst, the reduction is preferably carried out at 300° C. for 1 to 3 h in a mixed atmosphere of hydrogen and argon with a volume ratio of 1:9.

[0015] In the method for preparing the Pt / Hβ catalyst, the heating rate of reduction in a mixed atmosphere of hydrogen and argon is preferably 1 to 3° C. / min.

[0016] In the method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose, based on the mass of the catalyst as 100%, the loading amount of Pt in the Pt / Hβ catalyst is preferably 2% to 3%.

[0017] The beneficial effects of the present invention are as follows:

[0018] The invention uses isopropanol as a reaction solvent and a Pt / Hβ catalyst as a catalyst, and realizes the one-pot hydrogenolysis preparation of γ-valerolactone using D-xylose as a raw material in a high-pressure reactor under a hydrogen atmosphere. The preparation process of the invention is simple, the raw materials are easily available, the reaction process is environmentally friendly and pollution-free, and the catalytic system is relatively simple, the raw material conversion rate can reach 100%, and the γ-valerolactone yield can reach up to 52.1%. In addition, the Pt / Hβ catalyst has good stability, can be recycled after simple filtration and drying, can save resources, reduce costs, has important application value, and is suitable for industrial production and application. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described in detail below in conjunction with embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0020] The Pt / Hβ catalyst used in the following examples was prepared according to the following method:

[0021] 1g of commercially available Hβ zeolite (produced by Tianjin Nanhua Catalyst Co., Ltd. and a commodity purchased from the market) was heated to 550℃ at a heating rate of 5℃ / min in an air atmosphere, and calcined at a constant temperature for 4h to obtain activated Hβ zeolite. Then the activated Hβ zeolite was poured into a 25mL round-bottom flask, and 3.4649mL of 0.02g / mL H2PtCl6 (purchased from McLean (Shanghai) Biochemical Technology Co., Ltd.) aqueous solution was added. After ultrasonication for 30min, it was stirred at room temperature for 12h, the solvent was evaporated by rotary evaporation, and then dried at 100℃ for 12h to obtain a white solid powder. Subsequently, the obtained white solid powder was heated to 400℃ at a heating rate of 5℃ / min in an air atmosphere and calcined at a constant temperature for 4h. Finally, the temperature was raised to 300℃ at a heating rate of 2℃ / min in a mixed atmosphere with a volume ratio of hydrogen to argon of 1:9, and the Pt / Hβ catalyst was obtained by constant temperature reduction for 2h. The Pt loading in the Pt / Hβ catalyst is 2.5%.

[0022] Example 1

[0023] 0.1869 g of D-xylose and 30 mL of isopropanol were placed in a 50 mL autoclave, and 0.1 g of Pt / Hβ catalyst was added. The autoclave was evacuated with N2 at room temperature, and then hydrogen was introduced into the autoclave. The autoclave was reacted for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180°C, and a stirring rate of 600 rpm to complete the conversion of D-xylose. The autoclave was cooled to room temperature in an ice bath, and the catalyst was separated by centrifugation. The product was analyzed by gas chromatography (carrier gas: nitrogen, flow rate: 2.0 mL min -1, initial column temperature: 40°C, final column temperature: 250°C, heating rate: 10°C / min, 40°C for 3 min, 160°C for 1 min, 250°C for 3 min. Detector temperature: 250°C), γ-valerolactone yield was 52.1%.

[0024] Example 2

[0025] 0.0934 g of D-xylose and 30 mL of isopropanol were placed in a 50 mL autoclave, and 0.1 g of Pt / Hβ catalyst was added. The autoclave was evacuated with N2 at room temperature, and then hydrogen was introduced into the autoclave. The reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180° C., and a stirring rate of 600 rpm to complete the conversion of D-xylose. The autoclave was cooled to room temperature in an ice bath, and the catalyst was separated by centrifugation. The product was analyzed by gas chromatography (the analysis conditions were the same as in Example 1), and the yield of γ-valerolactone was 34.8%.

[0026] Example 3

[0027] 0.2804 g of D-xylose and 30 mL of isopropanol were placed in a 50 mL autoclave, and 0.1 g of Pt / Hβ catalyst was added. The autoclave was evacuated with N2 at room temperature, and then hydrogen was introduced into the autoclave. The reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180° C., and a stirring rate of 600 rpm to complete the conversion of D-xylose. The autoclave was cooled to room temperature in an ice bath, and the catalyst was separated by centrifugation. The product was analyzed by gas chromatography (the analysis conditions were the same as in Example 1), and the yield of γ-valerolactone was 43.9%.

[0028] Example 4

[0029] 0.1869 g of D-xylose and 30 mL of isopropanol were placed in a 50 mL autoclave, and 0.075 g of Pt / Hβ catalyst was added. The autoclave was evacuated with N2 at room temperature, and then hydrogen was introduced into the autoclave. The reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180° C., and a stirring rate of 600 rpm to complete the conversion of D-xylose. The autoclave was cooled to room temperature in an ice bath, and the catalyst was separated by centrifugation. The product was analyzed by gas chromatography (the analysis conditions were the same as in Example 1), and the yield of γ-valerolactone was 37.0%.

[0030] Example 5

[0031] 0.1869 g of D-xylose and 30 mL of isopropanol were placed in a 50 mL autoclave, and 0.125 g of Pt / Hβ catalyst was added. The autoclave was evacuated with N2 at room temperature, and then hydrogen was introduced into the autoclave. The reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180° C., and a stirring rate of 600 rpm to complete the conversion of D-xylose. The autoclave was cooled to room temperature in an ice bath, and the catalyst was separated by centrifugation. The product was analyzed by gas chromatography (the analysis conditions were the same as in Example 1), and the yield of γ-valerolactone was 45.0%.

[0032] Example 6

[0033] In this example, the reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 2.5 MPa, a temperature of 180° C., and a stirring rate of 600 rpm. The other steps were the same as those in Example 1, and γ-valerolactone was obtained with a yield of 40.1%.

[0034] Example 7

[0035] In this example, the reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3.5 MPa, a temperature of 180° C., and a stirring rate of 600 rpm. The other steps were the same as those in Example 1, and γ-valerolactone was obtained with a yield of 41.1%.

[0036] Example 8

[0037] In this example, the reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 170° C., and a stirring rate of 600 rpm. The other steps were the same as those in Example 1, and γ-valerolactone was obtained with a yield of 33.9%.

[0038] Example 9

[0039] In this example, the reaction was carried out for 15 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 190° C., and a stirring rate of 600 rpm. The other steps were the same as those in Example 1, and γ-valerolactone was obtained with a yield of 49.1%.

[0040] Example 10

[0041] In this example, the reaction was carried out for 14 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180° C., and a stirring rate of 600 rpm. The other steps were the same as those in Example 1, and γ-valerolactone was obtained with a yield of 50.2%.

[0042] Embodiment 11

[0043] In this example, the reaction was carried out for 16 h under a hydrogen atmosphere, a pressure of 3 MPa, a temperature of 180° C., and a stirring rate of 600 rpm. The other steps were the same as those in Example 1, and γ-valerolactone was obtained with a yield of 49.1%.

Claims

1. A method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose, characterized in that: D-xylose and isopropanol are placed in a high-pressure reactor, a Pt / Hβ catalyst is added, and the reaction is stirred for 8 to 20 hours under a hydrogen atmosphere, a pressure of 1.5 to 4.5 MPa, and a temperature of 130 to 210° C. After the reaction is completed, the mixture is cooled to room temperature, and the catalyst is separated by centrifugation to obtain γ-valerolactone; The mass ratio of D-xylose to Pt / Hβ catalyst is 0.5-4:1; The preparation method of the Pt / Hβ catalyst is as follows: commercially available Hβ zeolite is calcined at 500-600° C. for 3-5 hours in an air atmosphere to obtain activated Hβ zeolite; then, the activated Hβ zeolite is used as a carrier, H2PtCl6 is loaded by an impregnation method, and then calcined at 350-450° C. for 3-5 hours in an air atmosphere, and finally reduced at 200-400° C. for 1-3 hours in a mixed atmosphere of hydrogen and argon to obtain a Pt / Hβ catalyst; based on the mass of the catalyst being 100%, the loading amount of Pt in the Pt / Hβ catalyst is 0.5%-5%.

2. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1, characterized in that: In the preparation method of the Pt / Hβ catalyst, commercially available Hβ zeolite is calcined at 550° C. for 4 hours in an air atmosphere to obtain activated Hβ zeolite.

3. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1, characterized in that: In the preparation method of the Pt / Hβ catalyst, activated Hβ zeolite is used as a carrier, H2PtCl6 is loaded by an impregnation method, and then calcined at 400° C. for 4 hours in an air atmosphere.

4. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to any one of claims 1 to 3, characterized in that: In the preparation method of the Pt / Hβ catalyst, the heating rate of the calcination is 3-5°C / min.

5. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1, characterized in that: In the preparation method of the Pt / Hβ catalyst, the catalyst is reduced at 300° C. for 1 to 3 hours in a mixed atmosphere of hydrogen and argon with a volume ratio of 1:

9.

6. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1 or 5, characterized in that: In the preparation method of the Pt / Hβ catalyst, the heating rate of reduction in a mixed atmosphere of hydrogen and argon is 1-3°C / min.

7. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1, characterized in that: Based on 100% of the mass of the catalyst, the loading amount of Pt in the Pt / Hβ catalyst is 2% to 3%.

8. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1, characterized in that: D-xylose and isopropanol are placed in a high-pressure reactor, a Pt / Hβ catalyst is added, and the reaction is stirred for 12 to 16 hours in a hydrogen atmosphere, a pressure of 2.5 to 3.5 MPa, and a temperature of 170 to 190°C.

9. The method for preparing γ-valerolactone by one-pot hydrogenolysis of D-xylose according to claim 1 or 8, characterized in that: The mass ratio of the D-xylose to the Pt / Hβ catalyst is 1.5-2.5:1.