Application of hierarchical porous molecular sieves in the preparation of cyclopentadiene and JP-10 aviation fuel

Abstract

This invention relates to the application of a hierarchical porous molecular sieve in the preparation of cyclopentadiene and JP-10 aviation fuel. The hierarchical porous molecular sieve is one or more of the following: H-ZSM-5, H-β, H-Y, H-USY, La-Y, H-MOR molecular sieves with hierarchical pore structures; sulfonated SBA-15, MCM-41, Ti-SBA-15, Ti-MCM-41, Zr-MCM-41, and Zr-SBA-15; the hierarchical pore structure includes micropores and mesopores. The catalyst and raw materials used in this invention are inexpensive and readily available, the preparation process is simple, and it exhibits high activity and selectivity for the rearrangement reaction of furfuryl alcohol, the hydrogenation reaction of hydroxycyclopentenone, and the dehydration reaction. This invention provides a low-cost and efficient synthetic method for synthesizing JP-10 aviation fuel from furfuryl alcohol, a lignocellulose-based platform compound.

Description

Technical Field

[0001] This invention relates to the field of biomass catalytic conversion, specifically to the application of hierarchical porous molecular sieves in the preparation of JP-10 aviation fuel. Background Technology

[0002] The dwindling fossil resources and the massive greenhouse gas emissions from fossil fuel combustion are increasingly prominent environmental problems. Coupled with the continuously increasing societal demand for energy, the development of new energy sources to replace fossil resources is imperative. The application of biomass as a renewable organic carbon source in the production of carbon materials, fuels, and chemicals has become a hot research topic.

[0003] JP-10 aviation fuel is a commonly used high-density aviation fuel internationally. According to the US military standard MIL-P-87107C-1989, its density is 0.935 g / cm³. 3 With a freezing point of -79℃ and a calorific value of 42.1 MJ / Kg, JP-10 possesses a higher energy density than conventional hydrocarbon fuels, making it a high-performance aviation fuel. It is widely used in supersonic fighter jets, cruise missiles, rockets, and other aircraft. JP-10 is a single-component fuel composed of bridging tetrahydrodicyclopentadiene with a purity of 98.5%. The current JP-10 synthesis route involves using bridging dicyclopentadiene as a raw material, hydrogenating it to bridging tetrahydrodicyclopentadiene, and then isomerizing it under the catalysis of catalysts such as AlCl3 and H2SO4 to form bridging tetrahydrodicyclopentadiene. This method produces numerous byproducts at each step, requiring complex separation processes. The acid-catalyzed isomerization step causes severe environmental pollution and has a low yield. Other methods exist for synthesizing JP-10 aviation fuel, but they all use cyclopentadiene or dicyclopentadiene derived from fossil fuels, making them highly dependent on non-renewable fossil energy sources.

[0004] Our research group has long been engaged in the catalytic conversion of biomass into petroleum products and chemicals (Chinese Invention Patent ZL201110346501.1 and ChemSusChem. 2012, 5, 1958–1966; Bioresource Technology. 2013, 134, 66–72; Chem. Commun., 2013, 49, 5727-5729). We have developed a series of routes for the efficient utilization of biomass and its platform compounds. Furfuryl alcohol is one of the important biomass platform compounds. The synthesis of JP-10 aviation fuel from renewable biomass and its platform compound furfuryl alcohol has also been reported in our previous work (Angew. Chem. Int. Ed., 2019, 131, 12282-12286 and CN 108117474A).

[0005] The above-disclosed synthetic routes all report the six-step synthesis of JP-10 from furfuryl alcohol. However, using H-USY as a catalyst, the yield of the target product cyclopentadiene decreased from 58.4% to 40.9% after 24 hours of reaction (see Figure S1 in Angew. Chem. Int. Ed., 2019, 131, 12282-12286). Summary of the Invention

[0006] In response to the technical problem of a significant decrease in the yield of the target product in the existing method for preparing JP-10 aviation fuel from furfuryl alcohol, the inventors discovered that the yield of the target product is affected by the stability of the catalyst. This was verified in further catalyst stability testing experiments. Specifically, in the dehydration reaction of 1,3-cyclopentanediol, the use of conventional catalysts such as H-ZSM-5, H-USY, H-β molecular sieves, or amorphous SiO2-Al2O3, Amberlyst resin, Nafion resin, etc., leads to poor catalyst stability in this step of the reaction.

[0007] Therefore, this invention utilizes multi-level porous catalysts such as H-ZSM-5, H-β, HY, H-USY, La-Y, and H-MOR molecular sieves, as well as sulfonated SBA-15, MCM-41, Ti-SBA-15, Ti-MCM-41, Zr-MCM-41, and Zr-SBA-15 catalysts with mesoporous structures in the key steps of the synthesis process of furfuryl alcohol to prepare JP-10 aviation fuel. This enables the activity of 1,3-cyclopentanediol to be essentially unchanged during a reaction time of up to 100 hours for the dehydration to prepare cyclopentadiene.

[0008] The present invention describes a method for preparing JP-10 aviation fuel from furfuryl alcohol. The catalyst used is simple, readily available, and inexpensive. In the preparation process, apart from hydrogen, no other reagents in specific proportions are required. The entire route is green and environmentally friendly, efficiently producing JP-10 aviation fuel using furfuryl alcohol, a renewable biomass platform compound.

[0009] The purpose of this invention is to provide the application of hierarchical porous molecular sieves in the process of preparing JP-10 aviation fuel from furfuryl alcohol;

[0010] This invention is achieved through the following technical solution:

[0011] On one hand, the present invention provides the application of an acid catalyst in the dehydration of 1,3-cyclopentanediol to prepare cyclopentadiene, wherein the acid catalyst is a hierarchical porous molecular sieve; the hierarchical porous molecular sieve is one or more of the following: H-ZSM-5, H-β, HY, H-USY, La-Y, H-MOR molecular sieves with hierarchical porous structures, sulfonated SBA-15, MCM-41, Ti-SBA-15, Ti-MCM-41, Zr-MCM-41, and Zr-SBA-15; the hierarchical porous structure includes micropores and mesopores.

[0012] As a preferred technical solution, the multi-level pore structure also includes large pores.

[0013] The hierarchical pore structure includes micropores and mesopores. The micropores have a diameter of less than 2 nm; the mesopores have a diameter of 2 nm to 50 nm; and the macropores have a diameter of more than 50 nm.

[0014] As a preferred technical solution, the ratio of the mass of the acid catalyst to the mass of the substrate solution in the dehydration reaction is between 0.01% and 20%.

[0015] As a preferred technical solution, the molecular sieve with a multi-level pore structure is obtained by post-processing the bulk molecular sieve.

[0016] Post-treatment methods include at least one of acid treatment, alkali treatment, hydrothermal treatment, and fluoride treatment.

[0017] The preferred method of acid treatment includes the following steps: adding molecular sieves to an acid solution of 0.001-0.2 mol / L, stirring at 20-100℃ for 0.1-10 hours, and then washing, filtering, drying, and calcining to prepare an acid-treated multi-level porous molecular sieve; wherein the mass ratio of molecular sieves to alkaline solution is between 0.001 and 1; the type of acid is one or a mixture of two or more of nitric acid, hydrochloric acid, oxalic acid, acetic acid, succinic acid, and citric acid; the drying temperature is between 60-120℃, and the calcination temperature is between 200-700℃.

[0018] The preferred alkali treatment includes the following steps: adding molecular sieves to an alkali solution of 0.001-0.2 mol / L, stirring at 0-90°C for 0.1-10 hours, and then washing, filtering, drying, and calcining to prepare an alkali-treated multi-level porous molecular sieve; wherein the mass ratio of molecular sieves to alkali solution is between 0.001 and 1; the alkali is one or a mixture of two or more of ammonia, NaOH, KOH, Na2CO3, and (NH4)2CO3; the drying temperature is between 60-120°C, and the calcination temperature is between 200-700°C.

[0019] The hydrothermal treatment preferably includes the following steps: reacting the molecular sieve with 0.01-2.0 mol / L NH4 + An ammonium-type molecular sieve is formed by ion exchange in a salt solution; then, it is treated with steam at 400-900℃ for 0.1-10 hours to prepare a hydrothermally treated hierarchical porous molecular sieve; wherein, the molecular sieve reacts with NH4+. + The mass ratio of the salt solution ranges from 0.001 to 1; NH4 + The salt solution is one or a mixture of two or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0020] The preferred steps of the fluoride treatment are as follows: adding a molecular sieve to a 0.001-0.2 mol / L fluoride solution, stirring at 0-100°C for 0.1-10 hours, followed by washing, filtration, drying, and calcination to prepare a fluorinated multi-level porous molecular sieve; wherein the mass ratio of the molecular sieve to the alkaline solution is between 0.001 and 1; and the type of fluoride is HF or NH₃. 4 One or more of F; drying temperature between 60-120℃, calcination temperature between 200-700℃.

[0021] On the other hand, the present invention provides the application of an acid catalyst in the process of preparing JP-10 aviation fuel from furfuryl alcohol, wherein the acid catalyst is the hierarchical porous molecular sieve described above.

[0022] The preparation of JP-10 aviation fuel using furfuryl alcohol as a raw material involves six reactions:

[0023]

[0024] Reaction route for the preparation of JP-10 from furfuryl alcohol

[0025] Furthermore, this invention provides a process for preparing JP-10 aviation fuel from furfuryl alcohol, comprising six reaction steps:

[0026] Reaction 1 involves the rearrangement reaction of furfuryl alcohol solution to prepare hydroxycyclopentenone under alkaline catalysis or without the addition of a catalyst.

[0027] Reaction 2 involves the reaction of hydroxycyclopentenone with hydrogen under the catalysis of a hydrogenation catalyst to prepare 1,3-cyclopentanediol;

[0028] Reaction 3 involves the dehydration of 1,3-cyclopentadiol to prepare cyclopentadiene using an acid catalyst.

[0029] Reaction 4 involves the reaction of cyclopentadiene with DA to produce dicyclopentadiene;

[0030] Reaction 5 involves the hydrogenation of dicyclopentadiene to produce bridged tetrahydrodicyclopentadiene;

[0031] Reaction 6 involves the isomerization of bridged tetrahydrodicyclopentadiene to generate hanging tetrahydrodicyclopentadiene;

[0032] In reaction six, the catalyst for the isomerization reaction of bridged tetrahydrodicyclopentadiene is any of the hierarchical porous molecular sieves described above, and the mass ratio of the catalyst to the mass of the reaction substrate solution is 0.01%-50%.

[0033] Preferably, in reaction three, the acid catalyst catalyzing the dehydration reaction of 1,3-cyclopentanediol is one or a mixture of two or more of the following catalysts.

[0034] Preferably, in reaction six, the catalyst for the isomerization reaction of bridged tetrahydrodicyclopentadiene is the hierarchical porous molecular sieve described above, and the mass ratio of the catalyst to the mass of the reaction substrate solution is 0.01%-50%.

[0035] Preferably, in reaction one, the alkaline catalyst is one or more of the following catalysts: NaOH, KOH, Na2CO3, NaHCO3, ammonia water with a mass concentration of 25%, Ca(OH)2, Mg(OH)2, CaO, MgO, magnesium aluminum hydrotalcite, nickel aluminum hydrotalcite, and CeO2; wherein the ratio of the mass of the alkaline catalyst to the mass of the reaction substrate solution of the rearrangement reaction is between 0 and 1000 ppm;

[0036] Preferably, in reaction two, the hydrogenation catalyst is one or a mixture of two or more of the following catalysts: supported metal catalyst, transition metal carbide and / or nitride catalyst, Raney nickel catalyst, and amorphous alloy catalyst; wherein, the supported metal catalyst uses one or a mixture of two or more of activated carbon, mesoporous carbon, silica, alumina, cerium oxide, and titanium oxide as a support, and supports one or more of the metals Pt, Pd, Ru, Ir, Ni, Co, and Cu; the mass content of the metal in the hydrogenation catalyst is 0.01-30%; the ratio of the mass of the hydrogenation catalyst to the mass of the hydrogenation reaction substrate solution is between 0.01% and 20%;

[0037] Preferably, in reaction four, the cyclopentadiene reacts with DA to generate dicyclopentadiene using one or more of the following or without a catalyst: hydrochloric acid, sulfuric acid, Nafion resin, Amberlyst resin, ZnCl2, or AlCl3 at a mass concentration of 36%; the mass ratio of the catalyst to the substrate solution is between 0.01% and 20%.

[0038] Preferably, in reaction five, the catalyst for the hydrogenation reaction is one or more of the following catalysts: supported metal catalyst, transition metal carbide and / or nitride catalyst, Raney nickel catalyst, and amorphous alloy catalyst; wherein, the supported metal catalyst uses one or more of the following as a support: activated carbon, mesoporous carbon, silica, alumina, cerium oxide, and titanium oxide, and supports one or more of the following metals: Pt, Pd, Ru, Ir, Ni, Co, and Cu; wherein the metal content in the supported catalyst is between 0.1% and 30%; and the mass ratio of the catalyst to the substrate solution is between 0.1% and 20%.

[0039] Preferably, in reaction one, the solvent for the preparation of hydroxycyclopentenone from furfuryl alcohol solution is water or a mixture of water and one or more of the following solvents: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide; the preparation of hydroxycyclopentenone from furfuryl alcohol solution is carried out in a batch reactor or a fixed-bed reactor at a reaction temperature between 160°C and 250°C; the mass concentration of furfuryl alcohol is 0.1%-10%; when using a batch reactor, the reaction time is between 0.01 h and 0.5 h; when using a fixed-bed reactor, the mass hourly space velocity is 1 h⁻¹. -1 -100h -1 between;

[0040] Preferably, reaction two, the hydrogenation reaction of hydroxycyclopentenone, uses one or more of the following solvents in a mixture: water, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide. The hydrogenation reaction of hydroxycyclopentenone can be carried out in a batch reactor or a fixed-bed reactor, with a reaction temperature between 0°C and 160°C; a hydrogen pressure between 1 MPa and 5 MPa; and a mass concentration of hydroxycyclopentenone of 5% to 50%. When using a batch reactor, the reaction time is between 0.1 h and 2 h; when using a fixed-bed reactor, the mass hourly space velocity (MSV) is 1 h⁻¹. -1 -10h -1 Between; the molar ratio of hydrogen to reactants is 2-1500;

[0041] Preferably, reaction three, the catalytic dehydration reaction of 1,3-cyclopentanediol, uses one or a mixture of two or more of the following solvents: water, methanol, ethanol, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, cyclohexane, and tridecane; the catalytic dehydration reaction of 1,3-cyclopentanediol can be carried out in a batch reactor or a fixed-bed reactor, with a reaction temperature between 180°C and 350°C; wherein the mass concentration of 1,3-cyclopentanediol is 0.1%-10%; when using a batch reactor, the reaction time is between 0.1 h and 12 h; when using a fixed-bed reactor, the mass hourly space velocity is 0.1 h⁻¹. -1 -10h -1 between;

[0042] Preferably, in reaction four, the cyclopentadiene DA reaction can be carried out without a solvent, or with one or more of the following solvents: water, benzene, toluene, benzyl alcohol, decahydronaphthalene, cyclohexane, n-heptane, and n-hexane; wherein the mass concentration of cyclopentadiene is 10%-100%; the reaction temperature is between 0℃ and 170℃; the cyclopentadiene DA reaction can be carried out in a batch reactor or a fixed-bed reactor, with a reaction temperature between 0℃ and 170℃; when using a batch reactor, the reaction time is between 0.1h and 10h; when using a fixed-bed reactor, the mass hourly space velocity is 0.2h. -1 -10h -1 between;

[0043] Preferably, in reaction five, the hydrogenation reaction of dicyclopentadiene can be carried out without a solvent, or with one or more of the following solvents: water, dichloromethane, dichloroethane, chloroform, benzene, toluene, benzyl alcohol, decahydronaphthalene, cyclohexane, n-heptane, and n-hexane; the hydrogenation reaction of dicyclopentadiene can be carried out in a batch reactor or a fixed-bed reactor, with a reaction temperature between 0°C and 160°C; a hydrogen pressure between 0.1 MPa and 4 MPa; wherein the mass concentration of bridged dicyclopentadiene is 10%-90%; when using a batch reactor, the reaction time is between 1 h and 12 h; when using a fixed-bed reactor, the volume hourly space velocity is 1 h⁻¹. -1 -10h -1 Between these points, the molar ratio of hydrogen to reactants is 2-150;

[0044] Preferably, in reaction six, the isomerization reaction of bridged tetrahydrodicyclopentadiene can be carried out without a solvent, or with a mixture of one or more of the following solvents: water, dichloromethane, dichloroethane, chloroform, benzene, toluene, benzyl alcohol, decahydronaphthalene, cyclohexane, n-heptane, and n-hexane; the isomerization reaction of bridged tetrahydrodicyclopentadiene can be carried out in a batch reactor or a fixed-bed reactor at a reaction temperature between 100°C and 220°C; wherein the mass concentration of bridged tetrahydrodicyclopentadiene is 20%-100%; when using a batch reactor, the reaction time is between 2 h and 24 h; when using a fixed-bed reactor, the volume hourly space velocity is 0.1 h⁻¹. -1 -10h -1 between;

[0045] Preferably, each step of reaction one through six can be carried out in a separate reactor or fixed-bed reactor, or two or more steps can be carried out simultaneously in a single reactor or fixed-bed reactor. For example, reaction four, due to its ambient temperature and pressure, can achieve a high conversion rate without a catalyst, and generally does not need to be considered as a single step reaction; reactions five and six are also often combined into a single step.

[0046] Beneficial effects

[0047] This invention provides a low-cost and efficient synthesis method for JP-10 aviation fuel from furfuryl alcohol, a lignocellulose-based platform compound, using renewable furfuryl alcohol as the raw material. The rearrangement, hydrogenation, dehydration, and isomerization reactions all employ common base catalysts, hydrogenation catalysts, and acid catalysts, which are simple, readily available, and have low catalyst costs, thus eliminating dependence on traditional fossil fuels.

[0048] Compared with the technical solution disclosed in invention patent application CN108117474A, the present invention uses H-ZSM-5, H-β, HY, H-USY, La-Y, and H-MOR molecular sieves with hierarchical porous structures, and sulfonated SBA-15, MCM-41, Ti-SBA-15, Ti-MCM-41, Zr-MCM-41, and Zr-SBA-15; which greatly improves the service life of the catalyst in the third step of the 1,3-cyclopentanediol dehydration reaction, thereby reducing the overall process cost of preparing JP-10 aviation fuel from furfuryl alcohol.

[0049] Therefore, the method of this patent is a very practical method for synthesizing JP-10 aviation fuel from renewable biomass platform compounds. Attached Figure Description

[0050] Figure 1 The furfuryl alcohol rearrangement product hydroxycyclopentenone 1 H-NMR spectrum;

[0051] Figure 2 The furfuryl alcohol rearrangement product hydroxycyclopentenone 13 C-NMR spectrum;

[0052] Figure 3 Hydrogenation of hydroxycyclopentenone to 1,3-cyclopentanediol 1 H-NMR spectrum;

[0053] Figure 4 Hydrogenation of hydroxycyclopentenone to 1,3-cyclopentanediol 13 C-NMR spectrum;

[0054] Figure 5(a) GC-MS spectrum of dicyclopentadiene - total ion chromatogram - 1;

[0055] Figure 5(b) GC-MS spectrum of dicyclopentadiene-1;

[0056] Figure 5(c) GC-MS spectrum of dicyclopentadiene - total ion chromatogram - 2;

[0057] Figure 5(d) GC-MS spectrum of dicyclopentadiene-2;

[0058] Figure 6(a) Total ion chromatogram of tetrahydrodicyclopentadiene;

[0059] Figure 6(b) GC-MS diagram of tetrahydrodicyclopentadiene-1;

[0060] Figure 6(c) GC-MS diagram of tetrahydrodicyclopentadiene -2;

[0061] Figure 7(a) Physico-adsorption diagram of nitrogen gas in acid-treated ZSM-5 molecular sieve;

[0062] Figure 7(b) Pore distribution of acid-treated ZSM-5 molecular sieve;

[0063] Figure 8(a) Physico-adsorption diagram of nitrogen gas in alkali-treated β molecular sieve;

[0064] Figure 8(b) Pore distribution of alkali-treated β molecular sieve;

[0065] Figure 9(a) Physico-adsorption diagram of nitrogen gas in hydrothermal treated USY molecular sieve;

[0066] Figure 9(b) Pore distribution of hydrothermally treated USY molecular sieve;

[0067] Figure 10(a) Physico-adsorption diagram of nitrogen gas in MOR molecular sieve treated with fluoride;

[0068] Figure 10(b) Pore distribution of fluoride-treated MOR molecular sieves. Detailed Implementation

[0069] The present invention will be described below with specific embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0070] 1. Experiment on the preparation of hydroxycyclopentenone from furfuryl alcohol (effect of catalyst, batch reactor)

[0071] In a 100mL reactor, 50mL of 2% furfuryl alcohol aqueous solution is added, along with a certain amount of alkaline catalyst, and the reaction is carried out at a certain temperature for a specific time.

[0072] Table 1. Rearrangement reaction activity of different base catalysts

[0073]

[0074]

[0075] As shown in Table 1, different base catalysts can effectively catalyze the furfuryl alcohol rearrangement reaction, yielding high yields of hydroxycyclopentenone. CeO2, being less basic, showed slightly poorer results. However, even without any catalyst, a 60% yield of hydroxycyclopentenone can still be achieved under optimal reaction conditions. The catalyst dosage significantly affects the reaction activity. Approximately 5 mg of NaOH yields the best results; values ​​higher or lower than this amount decrease the yield. The reaction time has a similar effect to the catalyst dosage, with an optimal yield at 0.02 h. Excessive time leads to further side reactions of the target product, reducing the yield; insufficient time results in incomplete conversion of some raw materials, resulting in a lower yield. The reaction temperature also has an optimal value: 240 °C maximizes the yield of hydroxycyclopentenone. Temperatures that are too high or too low lead to a slight decrease in yield.

[0076] 2. Experiment on the preparation of hydroxycyclopentenone from furfuryl alcohol (the effect of solvent, batch reactor)

[0077] Add 50 mL of a furfuryl alcohol aqueous solution or a mixture of water and other solvents of a certain concentration to a 100 mL reaction vessel, and react at 240 °C for 0.02 h with NaOH as a catalyst.

[0078] Table 2. Effect of different solvents on the rearrangement reaction activity

[0079]

[0080] As shown in Table 2, the yield of hydroxycyclopentenone decreased significantly with increasing concentration of the substrate furfuryl alcohol, but remained at a relatively high level. In actual production, it is necessary to comprehensively consider both yield and energy efficiency to obtain the optimal concentration. Using a mixed solvent has little impact on the yield of the target product; even with a wide range of fluctuations in the ratio of the mixed solvent to water, a high yield of hydroxycyclopentenone can still be obtained.

[0081] 3. Experiment on the preparation of hydroxycyclopentenone from furfuryl alcohol (fixed-bed reactor)

[0082] In a fixed-bed reactor, furfuryl alcohol aqueous solutions of different concentrations are pumped into the reactor at a certain rate using a liquid chromatography pump, and the reaction is carried out at different temperatures using magnesium aluminum hydrotalcite as a catalyst.

[0083] Table 3. Activity of furfuryl alcohol rearrangement reaction in fixed-bed reactors

[0084]

[0085]

[0086] As shown in Table 3, a higher yield of hydroxycyclopentenone can be obtained in a fixed-bed reactor under the same furfuryl alcohol concentration conditions compared to a batch reactor. Both excessively high and low space velocities in the fixed bed reduce the yield of hydroxycyclopentenone, similar to how reaction time affects yield in a batch reactor. Temperature has a significant impact on the formation of hydroxycyclopentenone; excessively low temperatures are detrimental to the formation of the target product, with 240℃ being the optimal reaction temperature.

[0087] 4. Experiment on hydrogenation of hydroxycyclopentenone (influence of catalyst, batch reactor)

[0088] In a 100 mL reactor, 50 mL of a 20% (w / w) hydroxycyclopentenone solution in THF solvent was added, along with 0.1 g of hydrogenation catalyst. The reaction was carried out at a specific temperature for a specific time.

[0089] Table 4. Hydrogenation reaction activity of different catalysts

[0090]

[0091]

[0092] As shown in Table 4, almost all common hydrogenation catalysts are effective for the hydrogenation of hydroxycyclopentenones, with Ni and Ru exhibiting the best activity. Metal loading and reaction time have a slight but not significant effect on the yield of 1,3-cyclopentanediol. Reaction temperature has a relatively large impact, with 160℃ being the optimal reaction temperature.

[0093] 5. Experiment on hydrogenation of hydroxycyclopentenone (influence of solvent, batch reactor)

[0094] In a 100 mL reactor, 50 mL of a hydroxycyclopentenone solution of a certain concentration was added, with 5% Ru / AC or Raney Ni as the catalyst and the catalyst addition amount being 0.1 g. The reaction was carried out at 160 °C for 1 h.

[0095] Table 5. Effect of different solvents on the hydrogenation reaction activity

[0096]

[0097]

[0098] As shown in Table 5, the solvent has a significant impact on the hydrogenation reaction. High yields of 1,3-cyclopentanediol can be obtained in aprotic solvents such as THF, DMF, and DMSO. However, the yield is relatively low in systems containing water or alcohols. Mixed solvents provide an intermediate effect. The substrate concentration has a significant impact on the yield of 1,3-cyclopentanediol; lower concentrations result in higher yields.

[0099] 6. Experiment on hydrogenation of hydroxycyclopentenone (fixed-bed reactor)

[0100] In a fixed-bed reactor, hydroxycyclopentenone THF solutions of different concentrations were pumped into the reactor at a certain rate using a liquid chromatography pump, and the reaction was carried out at different temperatures using Ru / AC as a catalyst.

[0101] Table 6. Hydrogenation Reaction Activity in Fixed-Bed Reactors

[0102]

[0103]

[0104] As shown in Table 6, substrate concentration has a significant impact on the hydrogenation reaction; excessively high substrate concentrations lead to a marked decrease in the yield of 1,3-cyclopentanediol. Space velocity has a relatively small effect on the yield of 1,3-cyclopentanediol. Reaction temperature has little effect on the yield of 1,3-cyclopentanediol in the high-temperature range of 160℃-300℃, but the yield decreases significantly when the temperature is below 100℃.

[0105] 7. Experiment on the preparation of cyclopentadiene from 1,3-cyclopentanediol (stirred batch reactor)

[0106] In a 100mL reactor, add 5mL of 1,3-cyclopentanediol, 45mL of tridecane, and 2g of acid catalyst, and react at a certain temperature for a specific time.

[0107] Table 7. Dehydration reaction activity of different catalysts

[0108]

[0109]

[0110] The specific preparation methods for the hierarchical porous molecules are described in Examples 253-256. Data from Table 7 shows that all hierarchical porous molecular sieves and sulfonated mesoporous catalysts exhibit excellent effects on the dehydration reaction of 1,3-cyclopentanediol, with Zr-MCM-41-SO3H and hierarchical HUSY-255 showing the best activity. When the reaction temperature exceeds 180℃ and the reaction time exceeds one hour, the yield of the product is not significantly affected.

[0111] 8. Experiment on the preparation of cyclopentadiene from 1,3-cyclopentanediol (fixed-bed reactor)

[0112] In a fixed-bed reactor, tetrahydrofuran solutions of 1,3-cyclopentanediol at different concentrations were pumped into the reactor at a certain rate using a liquid chromatography pump. The reaction was carried out at different temperatures using hierarchical porous Hβ-254 molecular sieve as a catalyst.

[0113] Table 8. Dehydration reaction activity in fixed-bed reactors

[0114]

[0115] As shown in Table 8, substrate concentration has little effect on the dehydration reaction; increasing the substrate concentration slightly reduces the cyclopentadiene yield. Space velocity has a relatively small effect on the cyclopentadiene yield. Reaction temperature in the high-temperature range of 180℃-350℃ has little effect on the cyclopentadiene yield.

[0116] 9. Stability test of 1,3-cyclopentanediol dehydration to prepare cyclopentadiene.

[0117] In a fixed-bed reactor, a 10% (w / w) solution of 1,3-cyclopentanediol tetrahydrofuran was pumped into the reactor at a controlled rate using a liquid chromatography pump, while maintaining a mass hourly space velocity (MSV) of 1 h⁻¹. -1 The reaction temperature was 250℃, and samples were taken at different reaction times to examine the stability of the catalyst.

[0118] Table 9. Dehydration Reaction Activity in Fixed-Bed Reactors

[0119]

[0120] The preparation of the hierarchical porous molecular sieves is detailed in Examples 253-256. As can be seen from the data in Table 9, all the hierarchical porous molecular sieves and sulfonated mesoporous catalysts exhibit excellent stability in the dehydration reaction of 1,3-cyclopentanediol; their activity remains almost unchanged after 100 hours of reaction. In contrast, the activity of ordinary HUSY molecular sieves decreases significantly after 10 hours of reaction, and after 40 hours, the activity drops to less than half of the initial activity. This fully demonstrates the superiority of the hierarchical porous molecular sieves and sulfonated mesoporous catalysts of this invention.

[0121] 10. Production of dicyclopentadiene from cyclopentadiene via DA reaction (stirred batch reactor)

[0122] Add 50 mL of cyclopentadiene to a 100 mL reactor, with or without a catalyst, and react at a specific temperature for a specific time.

[0123] Table 10. DA Reaction Activity of Different Catalysts

[0124]

[0125] As can be seen from the data in Table 10, cyclopentadiene can be readily converted to dicyclopentadiene via the DA reaction without a catalyst; even at room temperature, the yield of dicyclopentadiene remains considerable given a sufficiently long reaction time. Adding a small amount of acid as a catalyst can increase the reaction rate.

[0126] Therefore, in practice, the preparation of dicyclopentadiene from cyclopentadiene does not need to be carried out as a separate step; it is usually combined with other reactions in one step.

[0127] 11. Experiment on the hydrogenation of dicyclopentadiene to produce bridged tetrahydrodicyclopentadiene (different catalysts, batch reactor)

[0128] In a 100mL reactor, 50mL of a 50% dicyclopentadiene-cyclohexane solution was added, along with 1.0g of catalyst. After purging with hydrogen, the reactor was pressurized to 4MPa and reacted at a specific temperature for a specific time.

[0129] Table 11. Activity of different catalysts in the hydrogenation of dicyclopentadiene

[0130]

[0131] As can be seen from the data in Table 11, the catalysts listed in the table all have excellent effects on the hydrogenation reaction of dicyclopentadiene. Pd / MC can efficiently hydrogenate dicyclopentadiene to produce bridged tetrahydrodicyclopentadiene at room temperature.

[0132] 12. Experiment on the preparation of bridged tetrahydrodicyclopentadiene by hydrogenation of dicyclopentadiene (different solvents, batch reactor)

[0133] In a 100 mL reactor, add 50 mL of a 50% (w / w) solution of dicyclopentadiene and 1.0 g of 5% Pd / AC, and react at 140 °C for 5 h.

[0134] Table 12. Effect of different solvents on the hydrogenation reactivity of dicyclopentadiene

[0135]

[0136]

[0137] As can be seen from the data in Table 12, all the solvents listed in the table have good effects on the hydrogenation reaction of dicyclopentadiene, and good results can be obtained even without the addition of solvent. Hydrogen pressure has little effect on the reaction; high yields of bridged tetrahydrodicyclopentadiene can be obtained when the pressure is above 1 MPa.

[0138] 13. Experimental preparation of bridged tetrahydrodicyclopentadiene by hydrogenation of dicyclopentadiene (fixed-bed reactor)

[0139] In a fixed-bed reactor, cyclohexane solutions of dicyclopentadiene of different concentrations were pumped into the reactor at a certain rate using a liquid chromatography pump. 5% Pd / AC was used as a catalyst, and the reaction was carried out at different temperatures.

[0140] Table 13. Activity of dicyclopentadiene hydrogenation reaction in fixed-bed reactors

[0141]

[0142]

[0143] As shown in Table 13, under the conditions we used, the substrate concentration had little effect on the hydrogenation reaction. Even without a solvent, i.e., with a feed concentration of 100%, a high yield of bridged tetrahydrodicyclopentadiene could be obtained. Lower space velocities resulted in higher yields of bridged tetrahydrodicyclopentadiene; however, at exceptionally high space velocities, the yield of the target product decreased significantly. The reaction temperature in the high-temperature range of 100℃-200℃ had little effect on the yield of bridged tetrahydrodicyclopentadiene, but below 50℃, the yield decreased significantly.

[0144] 14. Experiment on the isomerization of bridged tetrahydrodicyclopentadiene to form hanging tetrahydrodicyclopentadiene (different solvents, batch reactor)

[0145] In a 100mL reactor, 50mL of a bridged tetrahydrodicyclopentadiene solution of a certain mass concentration was added, along with 5.0g of catalyst, and the reaction was carried out at a certain temperature for 2 hours.

[0146] Table 14. Effect of different solvents on the isomerization reaction activity

[0147]

[0148]

[0149] The preparation of the hierarchical porous molecular sieve is detailed in Examples 253-256. Data from Table 14 shows that the solvents listed in the table are all effective for the isomerization reaction of bridged tetrahydrodicyclopentadiene. The substrate concentration has a significant impact on the reaction; higher substrate concentrations favor the isomerization reaction. The hierarchical porous La-Y-254 molecular sieve can achieve very high isomerization yields, and exhibits good isomerization reactivity at temperatures above 100 degrees Celsius.

[0150] 15. Experiment on the preparation of hanging tetrahydrodicyclopentadiene by bridge-type tetrahydrodicyclopentadiene isomerization (fixed-bed reactor)

[0151] In a fixed-bed reactor, cyclohexane solutions of bridged tetrahydrodicyclopentadiene at different concentrations were pumped into the reactor at a certain rate using a liquid chromatography pump. The catalyst was a hierarchical porous HUSY-255 molecular sieve, and the reaction was carried out at different temperatures.

[0152] Table 15. Isomerization reaction activity in fixed-bed reactors

[0153]

[0154] As shown in Table 15, substrate concentration has a significant impact on the isomerization reaction; increasing the substrate concentration improves the yield of tetrahydrodicyclopentadiene. Lower space velocity has little effect on the yield of tetrahydrodicyclopentadiene. Reaction temperature in the high-temperature range of 160℃-220℃ has little effect on the yield of tetrahydrodicyclopentadiene, but when the temperature drops to 130℃, the yield of tetrahydrodicyclopentadiene decreases significantly.

[0155] As can be seen from the above examples, through six reactions, it is entirely possible to prepare tetrahydrodicyclopentadiene (TBD) from furfuryl alcohol in high yield. The purity of the obtained TDD is greater than 98.5%, which can be directly used as JP-10 aviation fuel. Furthermore, the catalysts used in this process are common and inexpensive alkaline catalysts, hydrogenation catalysts, and acid catalysts. Apart from hydrogen, no other additional consumables are required in this process, making it green and environmentally friendly. This is a highly efficient method for synthesizing JP-10 aviation fuel from the renewable biomass platform compound furfuryl alcohol.

[0156] Examples 113 and 114

[0157] In Examples 113 and 114 of this invention, Amberlyst-36 was used as a catalyst, and the reaction was carried out at the same temperature (140°C) for 8 hours, with a cyclopentadiene yield of 90%. However, when the resin was recycled a second time, the cyclopentadiene yield dropped to 13%. This shows that the catalyst cannot be recycled in the dehydration reaction of cyclopentadiol.

[0158] Comparative Example 1

[0159] ACS Sustainable Chem. Eng. 2016, 4, 6160-6166. reported the dehydration reaction of cyclopentanol. Figure 1 describes how Amberlyst-36 at 373 K for 8 hours can dehydrate cyclopentanol to cyclopentene with a yield of up to 52.8%. After condition optimization (140 °C), the yield of cyclopentene can reach 84.0%, and the Amberlyst-36 resin can be recycled up to 7 times without significant decrease in activity.

[0160] Comparing Comparative Example 1 with Examples 113 and 114, it can be seen that the dehydration reaction of cyclopentanediol is much more difficult than that of cyclopentanol. The catalysts for the dehydration of cyclopentanol are not suitable for the dehydration reaction of cyclopentanediol, and Amberlyst-36 is not a catalyst protected in this patent.

[0161] Examples 168-170

[0162] Examples 168-170 of this invention use a hierarchical porous SAPO-34 molecular sieve catalyst, achieving a 63% initial cyclopentadiene yield, which is comparable to the reactivity of other hierarchical porous molecular sieves. However, after 40 hours of reaction, the cyclopentadiene yield drops to 33%; after 100 hours, the yield is only 13%. This demonstrates that the hierarchical porous SAPO-34 molecular sieve cannot effectively improve the stability of cyclopentadiene dehydration. Furthermore, the hierarchical porous SAPO-34 molecular sieve is not a catalyst protected in this patent.

[0163] Comparative Example 2

[0164] The article "Synthesis and Catalytic Performance of Hierarchical Porous SAPO-34 Molecular Sieves" published in the first issue of Volume 25 of Industrial Catalysis in 2017 reported the synthesis of hierarchical porous molecular sieve SAPO-34 and its application in the methanol-to-olefins reaction. Figure 5 shows that hierarchical porous SAPO-34 showed no significant deactivation within a 400-minute reaction time.

[0165] Comparing Comparative Example 2 with Examples 168-170, it can be seen that non-conventional hierarchical porous molecular sieve catalysts can improve the stability of cyclopentanediol dehydration.

[0166] Example 253: Preparation of multi-level porous molecular sieves by acid treatment

[0167] Add 2g of ZSM-5 or 2g of Y-type molecular sieve to 100mL of 0.05mol / L oxalic acid solution, stir at 90℃ for 2 hours, wash three times, filter, dry at 120℃ for 6 hours, and calcine at 550℃ for 2 hours to prepare acid-treated hierarchical porous ZSM-5 molecular sieve. The nitrogen physisorption of hierarchical porous ZSM-5 is shown in Figure 7(a), exhibiting a clear hysteresis loop characteristic curve typical of mesoporous materials. The calculated pore size distribution of hierarchical porous ZSM-5 is shown in Figure 7(b), with pore sizes ranging from 5-30nm. The prepared catalysts are designated as hierarchical porous HZSM-5-253 and hierarchical porous HY-253.

[0168] Example 254 Preparation of multi-level porous molecular sieves by alkali treatment

[0169] Two g of β or LaY molecular sieve was added to 100 mL of 0.05 mol / L ammonia solution, stirred at 30 °C for 2 hours, washed three times, filtered, dried at 120 °C for 6 hours, and calcined at 550 °C for 2 hours to prepare an alkali-treated hierarchical porous β molecular sieve. The nitrogen physisorption of the hierarchical porous β molecular sieve is shown in Figure 8(a), exhibiting a distinct hysteresis loop characteristic curve typical of mesoporous materials. The calculated pore size distribution of the hierarchical porous β molecular sieve is shown in Figure 8(b), with pore sizes ranging from 5 to 30 nm. The prepared catalysts are designated as hierarchical porous Hβ-254 and hierarchical porous LaY-254.

[0170] Example 255: Hydrothermal treatment preparation of multi-level porous molecular sieves

[0171] 2g of USY or 2g of SAPO-34 molecular sieve were added to 100mL of 0.2mol / L ammonium chloride solution for ion exchange to form an ammonium-type molecular sieve. Then, the solution was treated with steam at 600℃ for 2 hours to obtain a hydrothermally treated hierarchical USY molecular sieve. The nitrogen physisorption of the hierarchical USY molecular sieve is shown in Figure 9(a), exhibiting a hysteresis loop characteristic curve typical of mesoporous materials. The calculated pore size distribution of the hierarchical USY molecular sieve is shown in Figure 9(b), with pore sizes ranging from 5-30nm. The prepared catalysts are designated as hierarchical HUSY-255 and hierarchical SAPO-34-255.

[0172] Example 256: Preparation of multi-level porous molecular sieves by fluorination treatment

[0173] Two g of MOR molecular sieve was added to 100 mL of 0.1 mol / L ammonium fluoride solution, stirred at 20 °C for 2 hours, washed three times, filtered, dried at 120 °C for 6 hours, and calcined at 550 °C for 2 hours to prepare a fluoride-treated hierarchical porous MOR molecular sieve. The nitrogen physisorption of the hierarchical porous MOR molecular sieve is shown in Figure 10(a), exhibiting a clear hysteresis loop characteristic curve typical of mesoporous materials. The calculated pore size distribution of the hierarchical porous MOR molecular sieve is shown in Figure 10(b), with pore sizes ranging from 5 to 50 nm. The prepared catalyst is designated as hierarchical porous HMOR-256.

Claims

1. Use of an acid catalyst for the dehydration of 1,3-cyclopentanediol to prepare cyclopentadiene, characterized in that: The acid catalyst is a hierarchical pore molecular sieve; The hierarchical pore molecular sieve is one or two or more of H-ZSM-5, H-beta, H-Y, H-USY, La-Y, H-MOR molecular sieve, sulfonated SBA-15, MCM-41, Ti-SBA-15, Ti-MCM-41, Zr-MCM-41, Zr-SBA-15 with hierarchical pore structure; The hierarchical pore structure includes micropore, mesopore and macropore.

2. The application according to claim 1, wherein: The mass ratio of the acid catalyst to the substrate solution for the dehydration reaction is between 0.01% and 20%.

3. The application according to claim 1, wherein: The molecular sieve with hierarchical pore structure is obtained by post-treatment of a bulk molecular sieve; The post-treatment method includes at least one of acid treatment, alkali treatment, hydrothermal treatment and fluoride treatment.

4. The application according to claim 3, wherein: The acid treatment includes the following steps: The molecular sieve is added to an acid solution with a concentration of 0.001-0.2 mol / L, stirred at 20-100 ℃ for 0.1-10 hours, and then washed, filtered, dried and calcined to obtain the acid-treated hierarchical pore molecular sieve; The mass ratio of the molecular sieve to the acid solution is between 1 and 1000; the acid is one or a mixture of two or more of nitric acid, hydrochloric acid, oxalic acid, acetic acid, succinic acid and citric acid; the drying temperature is between 60 and 120 ℃, and the calcination temperature is between 200 and 700 ℃; The alkali treatment includes the following steps: The molecular sieve is added to an alkali solution with a concentration of 0.001-0.2 mol / L, stirred at 0-90 ℃ for 0.1-10 hours, and then washed, filtered, dried and calcined to obtain the alkali-treated hierarchical pore molecular sieve; The mass ratio of the molecular sieve to the alkali solution is between 1 and 1000; the alkali is one or a mixture of two or more of ammonia, NaOH, KOH, Na2CO3 and (NH4)2CO3; the drying temperature is between 60 and 120 ℃, and the calcination temperature is between 200 and 700 ℃; The hydrothermal treatment includes the following steps: Ion exchange with 0.01-2.0 mol / L NH4 + salt solution to form ammonium type molecular sieve; then, water vapor is introduced at 400-900 ℃ for 0.1-10 hours to prepare the hydrothermally treated hierarchical pore molecular sieve. wherein the molecular sieve is in contact with NH4 + The mass ratio of the salt solution ranges between 1-1000; NH4 + The salt solution is one of ammonium chloride, ammonium sulfate, ammonium nitrate or a mixture of two or more thereof. The fluoride treatment includes the following steps: The molecular sieve is added to a fluoride solution with a concentration of 0.001-0.2 mol / L, stirred at 0-100 ℃ for 0.1-10 hours, and then washed, filtered, dried and calcined to obtain the fluoride-treated hierarchical pore molecular sieve; The mass ratio of the molecular sieve to the fluoride solution is between 1 and 1000; the fluoride is one or a mixture of two or more of HF and NH4F; the drying temperature is between 60 and 120 ℃, and the calcination temperature is between 200 and 700 ℃.

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