Method for preparing fuel precursor by catalyzing furfural and cyclopentanone with Cu-Ni bimetallic multifunctional catalyst

Abstract

The invention belongs to the technical field of chemical preparation, and particularly relates to a method for preparing a fuel precursor by catalyzing furfural and cyclopentanone with a Cu-Ni bimetallic multifunctional catalyst. The preparation method comprises the following steps: under a solvent-free condition, taking cyclopentanone and furfural as raw materials, and carrying out aldol condensation series hydrodeoxygenation reaction in a hydrogen atmosphere under the action of a Cu-Ni bimetallic multifunctional catalyst to obtain a C10 and C15 mixed fuel precursor taking 2, 5-bis (furan-2-yl methyl) cyclopentanone as a main component. The method has few operation steps, aldol condensation and hydrogenation reactions can be connected in series, forward movement of the aldol condensation reaction is effectively promoted through continuous hydrogenation of the intermediate, reverse aldol condensation reaction is inhibited, and the product selectivity and yield of the whole process are improved. The reaction product is liquid, and no solvent is used in the next step of hydrodeoxygenation reaction, so that no solvent is used in the whole reaction route of fuel synthesis, and the method is more environment-friendly, greener and more efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical preparation, and in particular to a method for preparing a fuel precursor by catalyzing furfural and cyclopentanone using a Cu-Ni bimetallic multifunctional catalyst. Background Art

[0002] 2,5-Bis(furan-2-ylmethyl)cyclopentanone is a valuable fuel precursor with potential applications in specialty chemicals and electronic photolithography materials. Thanks to its cyclic structure, the fuel obtained by hydrodeoxygenation of 2,5-bis(furan-2-ylmethyl)cyclopentanone has a higher density and volumetric calorific value than traditional fuels, and a lower melting point—all desirable properties for high-quality fuels.

[0003] In recent years, heterogeneous catalysts such as MgO-ZrO2 and KF / γ-Al2O3 have been used for the aldol condensation of cyclopentanone and furfural. However, these catalysts typically require large amounts of solvent (ChemCatChem, 2017, 9, 1765–1770. RSC Adv., 2019, 9, 3661–3668), increasing subsequent separation costs and environmental pollution. Wang et al. reported that solid acid catalyzed the aldol condensation of furfural and cyclopentanone under solvent-free conditions to produce 2-(furan-2-ylmethylene)cyclopentanone and 2,5-bis(furan-2-ylmethylene)cyclopentanone. However, the reaction inevitably produced humic substances (RSC Adv., 2017, 7, 16901–16907), which led to catalyst deactivation. To address the solvent dependency issue, Na-MgAlO catalysts have been reported for solvent-free catalysis of this reaction. However, since the resulting 2-(furan-2-ylmethylene)cyclopentanone and 2,5-bis(furan-2-ylmethylene)cyclopentanone are both solids, solvent still needs to be added during the subsequent hydrodeoxygenation process (Energy Fuels, 2020, 34, 7149–7159.), preventing full solvent-free operation. Wang et al. further proposed a tandem catalytic strategy to avoid the use of solvents by combining aldol condensation and hydrogenation reactions. However, the use of the noble metal catalyst Pd / C inevitably results in high costs.

[0004] In summary, there is an urgent need to develop an efficient, low-cost, solvent-free synthetic route to achieve the green synthesis of 2,5-bis(furan-2-ylmethyl)cyclopentanone. Summary of the Invention

[0005] In response to the above technical problems, the present invention provides a method for preparing a fuel precursor by catalyzing furfural and cyclopentanone using a Cu-Ni bimetallic multifunctional catalyst. Under the action of a non-precious metal catalyst, furfural and cyclopentanone are converted in one step to produce a C10 and C15 mixed fuel precursor mainly composed of 2,5-bis(furan-2-ylmethyl)cyclopentanone, thereby improving the cyclopentanone conversion rate and 2,5-bis(furan-2-ylmethyl)cyclopentanone selectivity. At the same time, this method does not require the use of solvents and is more environmentally friendly and efficient.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A method for preparing a fuel precursor by catalyzing furfural and cyclopentanone using a Cu-Ni bimetallic multifunctional catalyst, the method being as follows:

[0008] Under solvent-free conditions, cyclopentanone and furfural were used as raw materials. In the presence of hydrogen atmosphere and the action of Cu-Ni bimetallic multifunctional catalyst, a fuel precursor mainly composed of C10 and C15 mixed with 2,5-bis(furan-2-ylmethyl)cyclopentanone was obtained through aldol condensation and tandem hydrodeoxygenation reaction.

[0009] The reaction path of the present invention is as follows:

[0010]

[0011] The chemical structural formulas of furfural, cyclopentanone and products are shown in Table 1.

[0012] Table 1 Structural formula of the compound

[0013]

[0014]

[0015] In the above technical solution, further, the reaction is carried out in a batch reactor, the hydrogen pressure is 3-8 MPa, the reaction temperature is 130-180° C., and the reaction time is 0.5-24 h.

[0016] In the above technical solution, further, the Cu-Ni bimetallic multifunctional catalyst is prepared by coprecipitation method, and the Cu-Ni bimetallic multifunctional catalyst is prepared by formula xCu y Ni1 / MgAl represents, wherein x is the total content of Cu and Ni in the catalyst, x=3-20wt%, y is the stoichiometric ratio of Cu, y=1-5, and the molar ratio of Mg to Al is 1-5:1, preferably 1-3:1.

[0017] In the above technical solution, further, the method for preparing the catalyst comprises the following steps:

[0018] (1) Mg(NO3)2·6H2O, Al(NO3)3·9H2O, Cu(NO3)2·3H2O, and Ni(NO3)2·6H2O were dissolved in deionized water to obtain a mixed salt solution;

[0019] (2) adding a mixed solution of Na2CO3 and NaOH dropwise to the mixed salt solution at 30-110°C, preferably 40-100°C, more preferably 50-90°C, stirring, and adjusting the pH of the resulting mixture to 9-10 with a NaOH solution;

[0020] (3) aging at 60-90° C. for 12-24 h, washing, drying, and then calcining in a hydrogen atmosphere to obtain the Cu-Ni bimetallic multifunctional catalyst.

[0021] In the above technical solution, further, in the mixed solution of Na2CO3 and NaOH, the concentration of Na2CO3 is 1.5-2 mol / L, and the concentration of NaOH is 2-3 mol / L.

[0022] In the above technical solution, further, the concentration of the NaOH solution is 1-5 mol / L, preferably 2-4 mol / L, and more preferably 3-4 mol / L.

[0023] In the above technical solution, further, the drying temperature is 80-200° C., and the drying time is 4-48 hours.

[0024] In the above technical solution, further, the calcination temperature is 300-800°C, preferably 350-750°C, more preferably 400-700°C, and the calcination time is 0.5-10h, preferably 1-8h, more preferably 2-6h.

[0025] The beneficial effects of the present invention are:

[0026] 1. The method of the present invention has fewer steps and can connect the aldol condensation and hydrogenation reactions in series. The continuous hydrogenation of the intermediate effectively promotes the forward movement of the aldol condensation reaction and inhibits the reverse aldol condensation reaction, thereby improving the product selectivity and yield of the overall process. The reaction product is a liquid, eliminating the need for solvents in the subsequent hydrodeoxygenation reaction. This eliminates the need for solvents throughout the entire fuel synthesis reaction route, making it more environmentally friendly, green, and efficient.

[0027] 2. The present invention prepares a Cu-Ni bimetallic multifunctional catalyst by a co-precipitation method, which has a large specific surface area and good stability, and exhibits good catalytic performance in the solvent-free aldol condensation and hydrogenation reaction of cyclopentanone and furfural.

[0028] 3. The catalyst preparation method of the present invention is simple, the reaction conditions are mild, and it can be used for actual industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Gas chromatography of the aldol condensation hydrogenation reaction of cyclopentanone and furfural in Example 1;

[0030] Figure 2 Gas chromatography of the aldol condensation hydrogenation reaction of cyclopentanone and furfural in Example 3;

[0031] Figure 3 This is the H NMR spectrum of the product FCFDH in Example 1;

[0032] Figure 4 This is the NMR carbon spectrum of the product FCFDH in Example 1;

[0033] Figure 5 This is the FCFH NMR hydrogen spectrum of the product in Example 4;

[0034] Figure 6 This is the FCFH NMR carbon spectrum of the product in Example 4;

[0035] Figure 7 This is the FCF H NMR spectrum of the product in Example 4;

[0036] Figure 8 This is the FCF NMR spectrum of the product in Example 4;

[0037] Figure 9 This is the FCH H NMR spectrum of the product in Example 1;

[0038] Figure 10 This is the FCH NMR carbon spectrum of the product in Example 1. DETAILED DESCRIPTION

[0039] The following examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0040] Unless otherwise specified, the materials used in the examples of the present invention can be obtained from commercial sources or prepared according to conventional methods well known to those skilled in the art.

[0041] Example 1

[0042] (1) Preparation of 5% Cu2Ni1 / MgAl (2:1) catalyst: 50 mL of a solution containing 80 mmol of Na2CO3 and 120 mmol of NaOH was slowly added dropwise to a vigorously stirred aqueous solution containing 40 mmol of Mg(NO3)2·6H2O, 20 mmol of Al(NO3)3·9H2O, 1.4 mmol of Cu(NO3)2·3H2O, and 0.7 mmol of Ni(NO3)2·6H2O. The pH of the resulting mixture was adjusted to 10 with a 3 mol / L NaOH solution. The mixture was maintained at 65°C for 24 h. The resulting slurry was washed with deionized water and dried at 100°C for 12 h. Finally, the resulting powder was reduced at 500°C in a hydrogen atmosphere for 4 h to obtain a 5% Cu2Ni1 / MgAl (2:1) catalyst.

[0043] (2) Preparation of fuel precursor: The reaction was carried out in a 50 mL batch reactor. 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added. A magnet was added. The reactor was first purged with nitrogen three times, then purged with hydrogen three times to remove air and then refilled with hydrogen to 4 MPa. Subsequently, the reactor was heated to 150°C at a speed of 500 rpm. After reacting for 10 h, the reactor was quickly cooled to room temperature with cold water. The reaction product was dissolved in 20 mL of dichloromethane, and tridecane, an internal standard, was added. The liquid product was analyzed using an Agilent 7890A gas chromatograph.

[0044] Example 2

[0045] (1) Preparation of 10% Cu2Ni1 / MgAl (2:1) catalyst: 50 mL of a solution containing 80 mmol of Na2CO3 and 120 mmol of NaOH was slowly added dropwise to a vigorously stirred aqueous solution containing 40 mmol of Mg(NO3)2·6H2O, 20 mmol of Al(NO3)3·9H2O, 2.8 mmol of Cu(NO3)2·3H2O, and 1.4 mol of Ni(NO3)2·6H2O. The pH of the resulting mixture was adjusted to 10 with a 3 mol / L NaOH solution. The mixture was maintained at 65°C for 24 h. The resulting slurry was washed with deionized water and dried at 100°C for 12 h. Finally, the resulting powder was reduced in a hydrogen atmosphere at 500°C for 4 h to obtain a 10% Cu2Ni1 / MgAl (2:1) catalyst.

[0046] (2) Preparation of fuel precursor: The reaction was carried out in a 50 mL batch reactor. 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added. A magnet was added. The reactor was first purged with nitrogen three times, then purged with hydrogen three times to remove air and then refilled with hydrogen to 3 MPa. Subsequently, the reactor was heated to 160°C at a speed of 500 rpm. After reacting for 10 h, the reactor was quickly cooled to room temperature with cold water. The reaction product was dissolved in 20 mL of dichloromethane, and tridecane, an internal standard, was added. The liquid product was analyzed using an Agilent 7890A gas chromatograph.

[0047] Example 3

[0048] (1) Preparation of 3% Cu2Ni1 / MgAl (2:1) catalyst: 50 mL of a solution containing 80 mmol of Na2CO3 and 120 mmol of NaOH was slowly added dropwise to a vigorously stirred aqueous solution containing 40 mmol of Mg(NO3)2·6H2O, 20 mmol of Al(NO3)3·9H2O, 0.8 mmol of Cu(NO3)2·3H2O, and 0.4 mmol of Ni(NO3)2·6H2O. The pH of the resulting mixture was adjusted to 10 with a 3 mol / L NaOH solution. The mixture was maintained at 65°C for 24 h. The resulting slurry was washed with deionized water and dried at 100°C for 12 h. Finally, the resulting powder was reduced in a hydrogen atmosphere at 500°C for 4 h to obtain a 3% Cu2Ni1 / MgAl (2:1) catalyst.

[0049] (2) Preparation of fuel precursor: The reaction was carried out in a 50 mL batch reactor. 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added. A magnet was added. The reactor was first purged with nitrogen three times, then purged with hydrogen three times to remove air and then refilled with hydrogen to 6 MPa. Subsequently, the reactor was heated to 150°C at a speed of 500 rpm. After reacting for 10 h, the reactor was quickly cooled to room temperature with cold water. The reaction product was dissolved in 20 mL of dichloromethane, and tridecane, an internal standard, was added. The liquid product was analyzed using an Agilent 7890A gas chromatograph.

[0050] Example 4

[0051] (1) Preparation of 5% Cu2Ni1 / MgAl (1:1) catalyst: 50 mL of a solution containing 80 mmol of Na2CO3 and 120 mmol of NaOH was slowly added dropwise to a vigorously stirred aqueous solution containing 20 mmol of Mg(NO3)2·6H2O, 20 mmol of Al(NO3)3·9H2O, 0.98 mmol of Cu(NO3)2·3H2O, and 0.49 mmol of Ni(NO3)2·6H2O. The pH of the resulting mixture was adjusted to 10 with a 3 mol / L NaOH solution. The mixture was maintained at 65°C for 24 h. The resulting slurry was washed with deionized water and dried at 100°C for 12 h. Finally, the resulting powder was reduced at 500°C in a hydrogen atmosphere for 4 h to obtain a 5% Cu2Ni1 / MgAl (1:1) catalyst.

[0052] (2) Preparation of fuel precursor: The reaction was carried out in a 50 mL batch reactor. 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added. A magnet was added. The reactor was first purged with nitrogen three times, then purged with hydrogen three times to remove air and then refilled with hydrogen to 4 MPa. Subsequently, the reactor was heated to 150°C at a speed of 500 rpm. After reacting for 10 h, the reactor was quickly cooled to room temperature with cold water. The reaction product was dissolved in 20 mL of dichloromethane, and tridecane, an internal standard, was added. The liquid product was analyzed using an Agilent 7890A gas chromatograph.

[0053] Example 5

[0054] (1) Preparation of 5% Cu2Ni1 / MgAl (3:1) catalyst: 50 mL of a solution containing 80 mmol of Na2CO3 and 120 mmol of NaOH was slowly added dropwise to a vigorously stirred aqueous solution containing 30 mmol of Mg(NO3)2·6H2O, 10 mmol of Al(NO3)3·9H2O, 0.92 mmol of Cu(NO3)2·3H2O, and 0.46 mmol of Ni(NO3)2·6H2O. The pH of the resulting mixture was adjusted to 10 with a 3 mol / L NaOH solution. The mixture was maintained at 65°C for 24 h. The resulting slurry was washed with deionized water and dried at 100°C for 12 h. Finally, the resulting powder was reduced at 500°C in a hydrogen atmosphere for 4 h to obtain a 5% Cu2Ni1 / MgAl (3:1) catalyst.

[0055] (2) Preparation of fuel precursor: The reaction was carried out in a 50 mL batch reactor. 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added to each experiment. A magnet was also added. Before the experiment, the reactor was purged three times with nitrogen, then purged three times with hydrogen to remove air and refilled with hydrogen to 6 MPa. Subsequently, the reactor was heated to 150°C at a speed of 500 rpm. After reacting for 10 h, the reactor was quickly cooled to room temperature with cold water. The reaction product was dissolved in 20 mL of dichloromethane, and tridecane, an internal standard, was added. The liquid product was analyzed using an Agilent 7890A gas chromatograph.

[0056] The test results of Examples 1-5 are shown in Table 2.

[0057] Table 2 Test results of Examples 1-5

[0058]

[0059] Examples 6-8

[0060] The 5% Cu2Ni1 / MgAl (2:1) catalyst in Example 1 was used as a catalyst, 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added, a magnet was added, and the reactor was first purged with nitrogen three times, then purged with hydrogen three times to remove air and refilled with hydrogen to 6 MPa. Subsequently, the reactor was heated to a specific temperature at a speed of 500 rpm. After reacting for 10 hours, it was quickly cooled to room temperature with cold water. Tests were carried out at different reaction temperatures. The reaction results are shown in Table 3.

[0061] Table 3 Test results of Examples 6-8

[0062]

[0063] Examples 9-11

[0064] The 5% Cu2Ni1 / MgAl (2:1) catalyst in Example 1 was used as a catalyst, 10 mmol of cyclopentanone, 20 mmol of purified furfural, and 0.05 g of catalyst were added, a magnet was added, and the reactor was first purged with nitrogen three times, then purged with hydrogen three times to remove air and refilled with hydrogen to 5 MPa. Subsequently, the reactor was heated to 150°C at a speed of 500 rpm. After the reaction was completed, the reactor was quickly cooled to room temperature with cold water. Tests were carried out at different reaction times. The reaction results are shown in Table 4.

[0065] Table 4 Test results of Examples 9-11

[0066]

[0067] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Other variations or modifications may be made based on the above description. Obvious variations or modifications derived therefrom shall remain within the scope of protection of the present invention.

Claims

1. A method for preparing a fuel precursor from furfural and cyclopentanone using a Cu-Ni bimetallic multifunctional catalyst, characterized in that: The method is as follows: under solvent-free conditions, cyclopentanone and furfural are used as raw materials, and in a hydrogen atmosphere, under the action of a Cu-Ni bimetallic multifunctional catalyst, an aldol condensation and a series hydrodeoxygenation reaction are carried out to obtain a fuel precursor mainly composed of 2,5-bis(furan-2-ylmethyl)cyclopentanone and a mixture of C10 and C15.

2. The method according to claim 1, wherein the reaction is carried out in a batch reactor, the hydrogen pressure is 3-8 MPa, the reaction temperature is 130-180°C, and the reaction time is 0.5-24 h.

3. The method according to claim 1, wherein: The Cu-Ni bimetallic multifunctional catalyst is prepared by coprecipitation method. y Ni1 / MgAl represents, wherein x is the total content of Cu and Ni in the catalyst, x=3-20wt%, y is the stoichiometric ratio of Cu, y=1-5, and the molar ratio of Mg to Al is 1-5:1, preferably 1-3:

1.

4. The method according to claim 3, wherein: The preparation method of the catalyst comprises the following steps: (1) Mg(NO3)2·6H2O, Al(NO3)3·9H2O, Cu(NO3)2·3H2O, and Ni(NO3)2·6H2O were dissolved in deionized water to obtain a mixed salt solution; (2) adding a mixed solution of Na2CO3 and NaOH dropwise to the mixed salt solution at 30-110°C, preferably 40-100°C, more preferably 50-90°C, stirring, and adjusting the pH of the resulting mixture to 9-10 with a NaOH solution; (3) aging at 60-90° C. for 12-24 h, washing, drying, and then calcining in a hydrogen atmosphere to obtain the Cu-Ni bimetallic multifunctional catalyst.

5. The method according to claim 4, characterized in that: In the mixed solution of Na2CO3 and NaOH, the concentration of Na2CO3 is 1.5-2 mol / L, and the concentration of NaOH is 2-3 mol / L.

6. The method according to claim 4, characterized in that: The concentration of the NaOH solution is 1-5 mol / L, preferably 2-4 mol / L, more preferably 3-4 mol / L.

7. The method according to claim 4, characterized in that: The drying temperature is 80-200° C., and the drying time is 4-48 hours.

8. The method according to claim 4, wherein: The calcination temperature is 300-800° C., preferably 350-750° C., more preferably 400-700° C., and the calcination time is 0.5-10 h, preferably 1-8 h, more preferably 2-6 h.

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