Furfural aqueous phase rearrangement hydrogenation catalyst, preparation method thereof and method for preparing cyclopentanol by catalyzing furfural aqueous phase rearrangement hydrogenation

Abstract

The application discloses a furaldehyde aqueous phase rearrangement hydrogenation catalyst, a preparation method thereof and a method for preparing cyclopentanol by catalyzing furaldehyde aqueous phase rearrangement hydrogenation, the catalyst is a silica supported metal, the metal is at least one of copper, nickel, cobalt and zinc, the metal accounts for 0.25-11% of the total weight of the catalyst, the catalyst, furaldehyde and water are added into a batch type closed high-pressure reaction kettle, and cyclopentanol is prepared by catalytic selective hydrogenation under stirring, a zinc-doped copper phyllosilicate catalyst is prepared, the catalyst does not destroy the original copper phyllosilicate phase after modification, and the catalyst acidity, especially the Lewis acid site, is obviously improved; and the modified copper phyllosilicate catalyst is uniform in particles, high in specific surface area and acidity, low in price, renewable, and has a wide industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysts, in particular to a catalyst for the rearrangement and hydrogenation of furfural in aqueous phase, and a preparation method of the catalyst, and a method for preparing cyclopentanol by rearrangement and selective hydrogenation of furfural in aqueous phase using the catalyst. BACKGROUND

[0002] With the increasing consumption of non-renewable fossil fuels, the effective utilization of renewable biomass resources has become increasingly attractive. Biomass can be converted into fuels and chemicals. The industrial application of biomass is based on improving the competitiveness of biomass resources, developing methods for the preparation of inexpensive platform molecules, and effectively converting platform molecules into fuels and chemicals. Furfural is an important platform molecule that can be obtained from hemicellulose in lignocellulosic biomass and can be further converted into a series of liquid fuels, fuel additives and other chemicals, such as furfuryl alcohol (FOL), tetrahydrofurfuryl alcohol (THFOL), 2-methyltetrahydrofuran (MTHF), 2-methylfuran, isoprene, pentanediol, levulinic acid, etc. Currently, furfural is mainly used to produce furfuryl alcohol, but its development in the development of other downstream industrial products is limited. Therefore, it is of great practical significance to further study the high-quality utilization of furfural. Cyclopentanone (CPO) and cyclopentanol (CPL) are fine chemical raw materials and have been widely used as synthetic raw materials and solvents. For example, cyclopentanone and cyclopentanol have been used to prepare perfumes and pharmaceutical materials. In addition, cyclopentanone is widely used as a solvent in the electronics industry because it can easily dissolve various resins. Cyclopentyl methyl ether and cyclopentyl ethyl ether have the characteristics of high hydrophobicity, low solvent evaporation latent heat, difficulty in forming peroxides, and easy drying, and have been used as solvents for important chemical reactions such as Grignard reaction, coupling reaction, etc. The demand for cyclopentanone and cyclopentanol exceeds 1 million tons per year. Therefore, if both cyclopentanone and cyclopentanol can be effectively prepared from biomass-based furfural, it will be very valuable. Although the research on furan compounds has a history of several decades, the process is challenging due to two cases: the easy decomposition of furan into small oxygen-containing compounds and the accumulation of oligomers on the surface of the catalyst; the product selectivity is difficult to control. SUMMARY

[0003] The first object of the present application is to provide a catalyst for the rearrangement and hydrogenation of furfural in aqueous phase, which realizes the close combination of hydrogenation sites and acid sites, so that a series of tandem reactions such as hydrogenation rearrangement and ring opening of active intermediates are completed on the surface of the catalyst.

[0004] The second object of the present application is to provide a preparation method of the above-mentioned catalyst for the rearrangement and hydrogenation of furfural in aqueous phase.

[0005] The third object of the present application is to provide a method for preparing cyclopentanol by rearrangement and hydrogenation of furfural in aqueous phase using the above-mentioned catalyst,

[0006] To this end, the first technical solution provided by the present application is as follows:

[0007] The furaldehyde water-phase rearrangement hydrogenation catalyst is a metal supported on silica; the metal is at least one of copper, nickel, cobalt and zinc; and the metal accounts for 0.25-11% of the total weight of the catalyst.

[0008] Further, the furaldehyde water-phase rearrangement hydrogenation catalyst is Cu / SiO2, or Ni / SiO2, or Co / SiO2, or Cu.Zn / SiO2.

[0009] Further, in the Cu / SiO2, Ni / SiO2, Co / SiO2 catalyst, the Cu, Ni and Co account for 10% of the corresponding catalyst mass, respectively, based on 100% of the total mass of the furaldehyde water-phase rearrangement hydrogenation catalyst.

[0010] Further, in the Cu.Zn / SiO2 catalyst, the Cu accounts for 10% of the total mass of the catalyst, and the Zn accounts for 0.25-1% of the total mass of the catalyst, based on 100% of the total mass of the furaldehyde water-phase rearrangement hydrogenation catalyst.

[0011] The second technical solution provided by the present application is a preparation method of the furaldehyde water-phase rearrangement hydrogenation catalyst, which comprises the following steps in sequence: dissolving a metal salt in water, adding ammonia water for complexation, depositing on silica sol, evaporating ammonia at 70-100℃ for 4 hours, suction filtering and washing, drying at 60-120℃ for 12 hours, calcining in air, and reducing in a reducing atmosphere.

[0012] Further, in the preparation method of the furaldehyde water-phase rearrangement hydrogenation catalyst, the pH of the ammonia evaporation system environment is 5-9.

[0013] Further, in the preparation method of the furaldehyde water-phase rearrangement hydrogenation catalyst, the calcination temperature is 450-550℃, the temperature rising rate is 5℃ / min, and the time is 4-6 hours.

[0014] Further, in the preparation method of the furaldehyde water-phase rearrangement hydrogenation catalyst, the reduction temperature is 260-500℃, the temperature rising rate is 5℃ / min, and the time is 2-4 hours.

[0015] Further, in the preparation method of the furaldehyde water-phase rearrangement hydrogenation catalyst, the reducing atmosphere comprises a hydrogen atmosphere or a hydrogen-argon mixed gas; and the flow rate of the reducing atmosphere is 40-50 mL / min.

[0016] The last technical solution provided by the present application is the above-mentioned method for preparing cyclopentanol by rearranging and hydrogenating furfural in water phase, wherein the furfural, water and the catalyst provided in the first technical solution are added into a batch type closed high-pressure reaction kettle, and catalytic selective hydrogenation is carried out under stirring, the amount of the furfural is 3-5 mmol, the amount of the catalyst is 20-300 mg, the initial pressure of hydrogen is 1-6 MPa, the reaction temperature is 120-200 DEG C, and the reaction time is 30 min-720 min.

[0017] Further, in the above-mentioned method for preparing cyclopentanol by rearranging and hydrogenating furfural in water phase, the furfural, water and the catalyst provided in the first technical solution are added into a batch type closed high-pressure reaction kettle, and catalytic selective hydrogenation is carried out under stirring, the amount of the furfural is 5 mmol, the amount of the catalyst is 300 mg, the initial pressure of hydrogen is 4 MPa, the reaction temperature is 140 DEG C, and the reaction time is 6 hours.

[0018] Compared with the prior art, the technical solution provided by the present application has the following beneficial effects:

[0019] 1. The supported catalyst provided by the present application has a small particle size and good dispersity, provides more adsorption sites and active sites for catalytic reaction, increases the contact area of reactants and active metals, and has higher catalytic activity and conversion.

[0020] 2. The zinc metal catalyst in the catalyst provided by the present application has strong hydrogenation capacity and good ring closing capacity in the synthesis of five-membered rings, and the doping of zinc enhances the interaction between copper and the carrier, realizes the close combination of hydrogenation sites and acid sites, does not damage the original layered copper silicate structure, and makes the catalyst more easily promote the rearrangement of furfuryl alcohol to generate the important intermediate cyclopentanone and then hydrogenate to cyclopentanol.

[0021] 3. The technical solution provided by the present application uses non-noble metal copper and zinc as the catalyst, and makes the active intermediate complete a series of series reactions such as hydrogenation rearrangement and ring opening on the surface of the catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the X-ray diffraction analysis diagram of the catalysts of the copper silicate doped with different amounts of zinc in Examples 1, 4-6.

[0023] Figure 2 It is the infrared spectrum diagram of the catalysts of the copper silicate doped with different amounts of zinc in Examples 1, 4-6.

[0024] Figure 3 It is the ammonia adsorption and desorption result of the reduced catalysts of the copper silicate doped with different amounts of zinc in Examples 1, 4-6.

[0025] Figure 4Pyridine infrared spectra of the reduced catalysts of Examples 1, 4-6 for comparison of different zinc-doped cupric phyllosilicates.

[0026] Figure 5 Results of the cycle stability experiment for Example 11 DETAILED DESCRIPTION

[0027] The claims of the present application will be further explained with reference to the specific embodiments below, but without constituting any limitation thereto.

[0028] Example 1

[0029] 0.5 g of furfural and 12 mL of water were weighed into a reactor, and 0.3 g of a catalyst Cu / SiO2 (wherein SiO2 is the carrier and the active ingredient is Cu, and the weight of the active ingredient Cu is 10% of the total mass of the catalyst) was added. The reactor was purged with hydrogen for 3-4 times, and hydrogen was introduced to an initial pressure of 4 MPa, and the stirring device was turned on at about 400 r / min. The reaction was carried out at 140°C for 8 hours, and after the reaction was completed, the product was obtained by filtration and centrifugal separation. Gas chromatography-mass spectrometry was used for quantitative and qualitative analysis, and the results were as follows: the conversion rate of furfural was 100%, the yield of cyclopentanone was 15.9%, and the yield of cyclopentanol was 35%.

[0030] The Cu / SiO2 catalyst was prepared by the following method:

[0031] 4.53 g of Cu(NO3)2·3H2O was dissolved in 150 mL of deionized water, and then 40 mL of a 28wt% ammonia solution was added and stirred for 30 min. Then 40.0 g of silica sol was added, and the mixture was stirred to obtain a suspension. The suspension was transferred to a preheated oil bath and heated to 70°C, and stirred for 4 hours to allow the ammonia to slowly evaporate until the pH of the solution dropped to 6-7. The product was washed with deionized water three times and then placed in an oven and dried at 100°C for 12 hours. It was first placed in a muffle furnace, heated to 550°C at a rate of 5°C / min, and calcined for 5 hours. Then it was placed in a hydrogen atmosphere and heated to 260°C at a rate of 5°C / min and reduced for 2 hours.

[0032] Example 2

[0033] The preparation process and reaction conditions were similar to those of Example 1, except that Ni / SiO2 (wherein SiO2 is the carrier and the active ingredient is Ni, and the weight of the active ingredient Ni is 10% of the total mass of the catalyst) was used. The results were as follows: the conversion rate of furfural was 100%, the yield of tetrahydrofurfuryl alcohol was 95%, and the yields of cyclopentanone and cyclopentanol were both 0%.

[0034] The Ni / SiO2 catalyst was prepared by the following method:

[0035] Example 1 5.94 g of Ni(NO3)2-3H2O was weighed and dissolved in 150 mL of deionized water, followed by the addition of 40 mL of 28 wt% ammonia solution and stirring for 30 min. Then 40.0 g of silica sol was added, and the mixture was stirred to obtain a suspension, which was then transferred to a preheated oil bath and heated to 70°C, and stirred for 4 hours to allow ammonia to evaporate slowly until the pH of the solution dropped to 6-7. The product was washed with deionized water three times, placed in an oven, and dried at 100°C for 12 hours. It was first placed in a muffle furnace, heated to 550°C at a rate of 5°C / min, and calcined for 5 hours. Then it was placed in a hydrogen atmosphere, heated to 500°C at a rate of 5°C / min, and reduced for 2 hours.

[0036] Example 3

[0037] The preparation process and reaction conditions were similar to those of Example 1, except that the catalyst used was Co / SiO2 (wherein SiO2 was the carrier, the active component was Co, and the weight of the active component Co was 10% of the total mass of the catalyst). The results were 100% conversion of furfural, 89% yield of tetrahydrofurfuryl alcohol, and 5% yield of both cyclopentanone ring and pentanol.

[0038] The Co / SiO2 catalyst was prepared by the following method:

[0039] 5.93 g of Co(NO3)2-3H2O was weighed and dissolved in 150 mL of deionized water, followed by the addition of 40 mL of 28 wt% ammonia solution and stirring for 30 min. Then 40.0 g of silica sol was added, and the mixture was stirred to obtain a suspension, which was then transferred to a preheated oil bath and heated to 70°C, and stirred for 4 hours to allow ammonia to evaporate slowly until the pH of the solution dropped to 6-7. The product was washed with deionized water three times, placed in an oven, and dried at 60°C for 12 hours. It was first placed in a muffle furnace, heated to 550°C at a rate of 5°C / min, and calcined for 5 hours. Then it was placed in a hydrogen atmosphere, heated to 450°C at a rate of 5°C / min, and reduced for 2 hours.

[0040] Example 4

[0041] Take 0.5 g of furfural and 12 mL of water into the reactor, then add 0.3 g of catalyst Cu.Zn / SiO2 (wherein SiO2 is the carrier, the active components are Cu and Zn, the weight of the active component Cu is 10% of the total mass of the catalyst, and Zn is 0.25% of the total mass of the catalyst). Replace the air in the reactor with hydrogen for 3-4 times, and then pass hydrogen into the reactor to an initial pressure of 4 MPa. Start the stirring device at about 400 r / min, and then react at 140°C for 8 hours. After cooling, the product is obtained by filtration and centrifugation, and then subjected to qualitative and quantitative analysis by gas chromatography-mass spectrometry. The results are as follows: the conversion rate of furfural is 100%, the yield of cyclopentanone is 27.1%, and the yield of cyclopentanol is 71.9%.

[0042] The Cu.Zn / SiO2 catalyst is prepared by the following method:

[0043] Dissolve 4.53 g of Cu(NO3)2·3H2O and 0.13 g of Zn(NO3)2·6H2O in 150 mL of deionized water, then add 40 mL of a 28 wt% ammonia solution and stir for 30 min. Then add 40.0 g of silica sol, stir to obtain a suspension, and then transfer the suspension to a preheated oil bath to heat to 70°C. Stir for 4 hours to slowly evaporate the ammonia until the pH of the solution is reduced to 6-7. Wash the product with deionized water three times, and then place it in an oven to dry at 100°C for 12 hours. First, place it in a muffle furnace, heat to 550°C at a rate of 5°C / min, and calcine for 5 hours. Then, place it in a hydrogen atmosphere, heat to 260°C at a rate of 5°C / min, and reduce for 2 hours.

[0044] Example 5

[0045] The preparation process and reaction conditions are similar to those of Example 4, except that the catalyst used is Cu.Zn / SiO2 (wherein SiO2 is the carrier, the active components are Cu and Zn, the weight of the active component Cu is 10% of the total mass of the catalyst, and Zn is 0.5% of the total mass of the catalyst). The results are as follows: the conversion rate of furfural is 100%, the yield of cyclopentanone is 3.1%, and the yield of cyclopentanol is 94.0%.

[0046] The Cu.Zn / SiO2 catalyst is prepared by the following method:

[0047] Cu(NO3)2*3H2O and 0.27 g of Zn(NO3)2*6H2O were dissolved in 150 mL of deionized water, 40 mL of 28 wt% ammonia solution was added and stirred for 30 min. Then 40.0 g of silica sol was added and stirred to obtain a suspension, which was then transferred to a preheated oil bath to be heated to 100°C, and stirred for 4 hours to slowly evaporate ammonia until the pH of the solution dropped to 6-7. The product was washed with deionized water three times and then placed in an oven and dried at 100°C for 12 hours. It was first placed in a muffle furnace, heated to 550°C at a rate of 5°C / min, and calcined for 5 hours. Then it was placed in a hydrogen atmosphere and heated to 260°C at a rate of 5°C / min, and reduced for 2 hours.

[0048] Example 6

[0049] The preparation process and reaction conditions were similar to those of Example 5, except that the catalyst used was Cu.Zn / SiO2 (wherein SiO2 was the carrier, the active components were Cu and Zn, the weight of Cu was 10% of the total mass of the catalyst, and the weight of Zn was 1% of the total mass of the catalyst). The results were 100% conversion of furfural, 17.0% yield of cyclopentanone, and 80.9% yield of cyclopentanol.

[0050] The Cu.Zn / SiO2 catalyst was prepared by the following method:

[0051] Cu(NO3)2*3H2O and 0.54 g of Zn(NO3)2*6H2O were dissolved in 150 mL of deionized water, followed by the addition of 40 mL of 28 wt% ammonia solution and stirring for 30 min. Then 40.0 g of silica sol was added and stirred to obtain a suspension, which was then transferred to a preheated oil bath to be heated to 70°C, and stirred for 4 hours to slowly evaporate ammonia until the pH of the solution dropped to 6-7. The product was washed with deionized water three times and then placed in an oven and dried at 100°C for 12 hours. It was first placed in a muffle furnace, heated to 550°C at a rate of 5°C / min, and calcined for 5 hours. Then it was placed in a hydrogen atmosphere and heated to 260°C at a rate of 5°C / min, and reduced for 2 hours.

[0052] Example 7

[0053] The preparation process and reaction conditions were similar to those of Example 5, except that the initial pressure of the reaction was 3 MPa. The results were 100% conversion of furfural, 7.9% yield of cyclopentanone, and 89.3% yield of cyclopentanol.

[0054] Example 8

[0055] Similar to the preparation process and reaction conditions of Example 5, except that the initial pressure of the reaction was 5 MPa. The results were 100% conversion of furfural, 11.3% yield of cyclopentanone, and 85.2% yield of cyclopentanol.

[0056] Example 9

[0057] Similar to the preparation process and reaction conditions of Example 5, except that the reaction temperature was 200°C. The results were 100% conversion of furfural, 23.7% yield of cyclopentanone, and 75.1% yield of cyclopentanol.

[0058] Example 10

[0059] Similar to the preparation process and reaction conditions of Example 5, except that the reaction temperature was 120°C. The results were 80% conversion of furfural, 40% yield of furfuryl alcohol, 25.1% yield of cyclopentanone, and 14.9% yield of cyclopentanol.

[0060] Example 11

[0061] A stability test was conducted using the catalyst and reaction conditions of Example 5. After the reaction, the catalyst was separated by simple centrifugation. The recovered catalyst was directly used in the next reaction without any other treatment. The yield of cyclopentanol remained essentially unchanged when the catalyst was repeatedly used for 7 times, with a fluctuation of about 95%.

[0062] The formation of the layered silicate copper was confirmed by X-ray diffraction patterns Figure 1 and infrared spectra Figure 2 In Figure 2 , the peak at 670 cm -1 was attributed to the presence of δ OH band, and a shoulder peak v SiO appeared at 1040 cm -1 , thus indicating that the layered silicate copper existed in the 10Cu / SiO2 precursor, and it can be seen that the doping of Zn did not destroy the layered copper silicate structure of the catalyst, and the structure was retained. At the same time, when the doping amount of Zn increased, the intensity of the peak at 670 cm -1 was obviously enhanced, and the peak at 1040 cm -1 was also more obvious, and when the Zn content was 0.5%, the peak shape had the highest intensity, indicating that the highest content of copper silicate phase was generated. The presence of characteristic peaks at 2ɵ of 30.8°, 57.5°, and 62.4° in the XRD spectrum also proved that the copper silicate structure of the catalyst was not destroyed.

[0063] The surface acidity of the reduced catalysts was detected by ammonia adsorption and desorption as Figure 3All catalysts have two wide peaks in the range of 150 ~ 550 ℃, which belong to weak acid and medium strong acid sites respectively. The distribution range of ammonia adsorption and desorption area is obviously different, and the corresponding total acid amount point is different. The total acid amount of the acid sites of the reduced Cu.Zn / SiO2 catalyst increases with the doping of Zn.

[0064] The pyridine infrared Figure 4 It is found that the B acid (1540 cm -1 ) sites of the catalyst gradually increase with the doping of zinc. The L acid sites at 1600 and 1590 cm -1 are differentiated more and more with the doping of zinc, which shows that the type of L acid is changing. In the previous study, the hydrogenolysis of furfural to generate cyclopentanol requires the cooperation of metal and acid to promote the rearrangement of furfuryl alcohol to generate cyclopentanone, which may be the reason why the 10Cu0.5Zn / SiO2 catalyst exhibits excellent performance in the hydrogenolysis of furfural to generate cyclopentanol.

[0065] The preferred embodiments of the application are described in detail above, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the application and belong to the protection scope of the application.

Claims

1. A process for the preparation of cyclopentanol by rearrangement hydrogenation of furfural in aqueous phase, characterized in that, The furaldehyde, water, furaldehyde aqueous phase rearrangement hydrogenation catalyst are added into a batch closed high-pressure reaction kettle, and catalytic selective hydrogenation is carried out under stirring, wherein the furaldehyde is 3-5 mmol, the catalyst is 20-300 mg, the initial hydrogen pressure is 1-6 MPa, the reaction temperature is 120-200℃, and the reaction time is 30 min-720 min; The furaldehyde aqueous phase rearrangement hydrogenation catalyst is Cu.Zn / SiO2; According to 100% of the total mass of the furaldehyde aqueous phase rearrangement hydrogenation catalyst, the Cu in the Cu.Zn / SiO2 catalyst accounts for 10% of the total mass of the catalyst, and the Zn accounts for 0.25-1% of the total mass of the catalyst; The furaldehyde aqueous phase rearrangement hydrogenation catalyst is prepared by the following method: dissolving a metal salt in water, then depositing on silica sol after complexing with ammonia water, evaporating ammonia at 70-100℃ for 2-4 hours, filtering and washing, drying at 60-120℃ for 12 hours, first calcining in air, and then reducing in a reducing atmosphere at 260-500℃ for 2-4 hours.

2. The process for the rearrangement of furfural in aqueous phase to cyclopentanol according to claim 1, characterized in that, The ammonia evaporation system environment pH is 5-9.

3. The process for the rearrangement of furfural in aqueous phase to cyclopentanol according to claim 1, characterized in that, The calcination temperature is 450-550℃.

4. The process for the rearrangement of furfural in aqueous phase to cyclopentanol according to claim 1, characterized in that, The reducing atmosphere comprises a hydrogen atmosphere or a hydrogen inert gas mixture; and the flow rate of the reducing atmosphere is 40-50 mL / min.

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