Method for preparing high-density aviation fuel from turpentine and phenolic compound

Abstract

The invention discloses a method for preparing high-density aviation fuel from turpentine and phenolic compounds, which comprises the following specific steps: S1, under the catalysis of acid, adding the phenolic compounds and turpentine into a solvent for alkylation reaction to obtain an alkylation product with a bicyclic structure and a tricyclic structure; and S2, adding the alkylated product prepared in the step S1 into a solvent, and carrying out hydrodeoxygenation under the co-catalysis of Metal / C and a solid acid catalyst to generate the high-density aviation fuel. The high-density aviation fuel is prepared with high yield by taking the phenolic compound and turpentine as raw materials through a two-step method, the density of the aviation fuel is greater than 0.90 g / mL, and the aviation fuel is an aviation kerosene alkane compound with relatively excellent performance; biomass is used as a raw material, so that the method is a novel green route, and harmful substances are not generated.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis of compounds, and in particular to a method for preparing high-density aviation fuel from turpentine oil and phenolic compounds. Background Art

[0002] High-density hydrocarbon fuels usually refer to artificially synthesized fuels with a density greater than 0.80 g / cm 3 Alkane fuels provide important power guarantees for various aerospace vehicles such as missiles, rockets and fighters, and are the research focus in the field of propellants. With the development of modern advanced technology, it is very necessary to improve the flight performance of aircraft (including high speed, long range, large load and high flexibility, etc.), which also puts forward higher requirements for the power propulsion capability of aircraft. Among them, improving the density and volume calorific value of fuel is an important way to enhance the propulsion performance of aircraft at low cost. The greater the calorific value of the fuel, the greater the energy released by its unit volume combustion, and the smaller the required fuel tank volume, which is more beneficial to improving the performance of the aircraft. For an aircraft with a certain fuel tank volume, the higher the density of the fuel, the greater the fuel mass it can carry, and the longer the range of the aircraft; under the condition of a certain total thrust of the aircraft, the higher the density of the fuel it carries, the smaller the required fuel tank volume, which is conducive to the miniaturization of the aircraft and improving its penetration capability and flexibility.

[0003] Phenolic compounds have always played an important role in our production and life. For example, the widely used phenolic resins in production and life are mainly condensed from phenolic compounds (such as cresol and xylenol) and formaldehyde, and have good corrosion resistance, heat resistance, and mechanical properties (Energy & Fuels, 2021, 35 (22): 18385-18395). In the pharmaceutical field, phenolic compounds mainly play the role of intermediates, such as salicylic acid (o-hydroxybenzoic acid) is an intermediate for the drug aspirin. In the cosmetics field, 4-methoxyphenolic compounds are intermediates for the antioxidant BHA (3-tert-butyl-4-hydroxyanisole), and they all have irreplaceable roles. Also from the perspective of saving resources and protecting the environment, the use of lignin phenolic platform compounds to catalyze the conversion into polycyclic alkane fuels is a promising direction. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing high-density aviation fuel from turpentine and phenolic compounds, which method can simplify the preparation steps, improve the yield, and can prepare high-density aviation fuel with excellent performance

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A method for preparing high-density aviation fuel from turpentine and phenolic compounds, comprising the following steps:

[0006] S1. Under the catalytic action of an acid catalyst, turpentine oil and a phenolic compound are added to a solvent in a molar ratio of 1:(0.8-1.2) to undergo an alkylation reaction to obtain an alkylated product having a bicyclic structure and a tricyclic structure;

[0007] S2. Add the alkylation product prepared in step S1 into a solvent, and perform hydrodeoxygenation under the catalysis of Metal / C and a solid acid catalyst to generate high-density aviation fuel.

[0008] Preferably, in step S1, the acid catalyst is p-toluenesulfonic acid, Nafion, T-62MP, Amberlyst15, Al-MCM-41, HPW / SiO2, HPW / MCM-41, D600, CD750, CD250, SO 4 / ZrO 2 -TiO 2 One or more of .

[0009] Preferably, in step S1, the ratio between the mass of the acid catalyst and the total mass of the phenolic compound and turpentine oil is (0.01-0.5):1; the reaction temperature is 60-160°C, the reaction time is 9-21h; and the substrate concentration is 10-15mol / L.

[0010] Preferably, in step S1, the solvent is selected from one of propylene carbonate, toluene, cyclohexane, tetrahydrofuran, ethylene dichloride, dimethyl carbonate, n-octane and n-hexane.

[0011] Preferably, in step S1, the phenolic compound is one of o-methylphenol, p-methylphenol, m-methylphenol, xylenol, 4-ethylphenol, benzyl acetate, guaiacol, and phenol.

[0012] Preferably, in step S2, the Metal / C is one of Pd / C, Ru / C, and Rh / C; the solid acid catalyst is one of HY, H-Beta, H-MOR, and Al-MCM-41; and the mass ratio between the Metal / C and the solid acid catalyst is 1:(0.8-1.2).

[0013] Preferably, in step S2, the mass ratio between the amount of catalyst used and the alkylation product prepared in step S1 is (0.01-0.3):1; and the substrate concentration is 0.01-1 mol / L.

[0014] Preferably, in step S2, the hydrodeoxygenation reaction is carried out in a tank reactor; the temperature is 160-220°C, the reaction time is 6-14h, and the hydrogen pressure is 3-5MPa.

[0015] Preferably, in step S2, the solvent used is selected from one or more of cyclohexane, propylene carbonate, methanol, isopropanol, tridecane, toluene, tetrahydrofuran, N,N-dimethylformamide, n-hexane, ethyl acetate, and acetonitrile.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention uses phenolic compounds and turpentine as raw materials to effectively synthesize high-density aviation fuel through a two-step process. In the first step, the phenolic compounds form a preliminary intermediate product through a chemical reaction with turpentine, and then enter the second step to further optimize the product structure through the action of a catalyst to achieve high density, high stability and good combustion performance. The final fuel density is greater than 0.90g / mL, which makes it have significant advantages in the field of aviation fuel.

[0018] (2) The present invention innovatively uses biomass as raw material and adopts a green and sustainable route, which not only reduces dependence on petroleum resources, but also avoids the environmental burden of traditional fossil energy. Biomass raw materials are mainly derived from plant materials, which are renewable and have low carbon emissions. During the entire synthesis process, no harmful waste gas or toxic by-products are produced, which is in line with modern environmental protection concepts. Through the development of this new green route, the production cost of aviation fuel can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Example 10 Using phenol and turpentine as raw materials, the MS spectrum of the alkylation dimerization addition product;

[0020] Figure 2 Example 21 Using phenol and turpentine as raw materials, the MS spectrum of the alkylation trimerization addition product;

[0021] Figure 3 Example 21 GC spectrum of alkylation addition product using phenol and turpentine as raw materials;

[0022] Figure 4 Example 21 Using phenol and turpentine as raw materials, alkylation dimerization addition product 1 H-NMR spectrum;

[0023] Figure 5 Example 21 Using phenol and turpentine as raw materials, alkylation trimerization product 1 H-NMR spectrum;

[0024] Figure 6 Example 21 Using phenol and turpentine as raw materials, alkylated oxygen atoms participate in the reaction 1 H-NMR spectrum;

[0025] Figure 7 Example 21 Using phenol and turpentine as raw materials, alkylated oxygen atoms participate in the reaction 13 C-NMR spectrum;

[0026] Figure 8 Example 30 Using o-methylphenol and turpentine as raw materials, alkylation trimerization addition product 1 H-NMR spectrum;

[0027] Fig. 9 Example 30 Using o-methylphenol and turpentine as raw materials, alkylation dimerization addition product 1 H-NMR spectrum;

[0028] Fig.10 Example 31 Using p-methylphenol and turpentine as raw materials, alkylation dimerization addition product 1 H-NMR spectrum;

[0029] Fig.11 . GC spectrum of Example 41 aviation fuel precursor hydrodeoxygenation;

[0030] Fig.12 .Example 41 MS spectrum of hydrodeoxygenation of aviation fuel precursor. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with embodiments.

[0032] In the following examples, unless otherwise specified, all reagents used can be purchased from commercial sources or obtained according to known literature reports.

[0033] Example

[0034] A method for preparing high-density aviation fuel from turpentine and phenolic compounds, the specific steps are:

[0035] S1. Under the catalytic action of 0.7 mmol of an acid catalyst, a phenol compound (7 mmol, 0.712 g) and turpentine (7 mmol, 0.952 g) were added to 1 mL of a solvent, and an alkylation reaction was carried out at 60-160° C. for 9-21 h to obtain an alkylated product having a bicyclic structure and a tricyclic structure;

[0036] S2. Add (0.3 g, 1 mmol) of the alkylation product prepared in step S1 to 10 mL of solvent, and react at 160-220° C. and 3.5 MPa hydrogen pressure for 6-14 h under the co-catalysis of 30 mg Metal / C and a solid acid catalyst (the mass ratio of Metal / C to the solid acid catalyst is 1:1) to perform hydrodeoxygenation to generate high-density aviation fuel.

[0037] The difference between Examples 1-36 lies in the difference in the phenolic compound, catalyst, reaction temperature, solvent, and reaction time in step S1. The specific parameters are shown in Table 1 below:

[0038] Table 1. Effects of phenolic compounds, catalysts, temperature, solvents, and time on alkylation reactions

[0039]

[0040]

[0041] From the results in Table 1, it can be seen that the heterogeneous catalysts Amberlyst15, CD750, D600 and Nafion showed good catalytic performance in the catalytic alkylation reaction of turpentine and phenolic compounds, and achieved medium to high yields. Among them, Nafion had the best catalytic performance, and the yield of dimerization products reached 95% after 15h reaction at 100°C. By screening different solvents, it was found that toluene, cyclohexane and propylene carbonate had relatively good effects on the reaction, but cyclohexane was selected as the solvent from the perspective of environmental greenness. By screening different reaction times, it was found that extending the time would not increase the product yield. The yield of dimerization products after 21h reaction was 93%, which was not much different from the result of 15h reaction. At the same time, for the alkylation reaction of other phenolic compounds, it was found that higher yields could be achieved.

[0042] Since the service life of the catalyst needs to be examined in practical applications, phenol (7mmol, 0.712g) and turpentine (7mmol, 0.952g) were added to 1mL of solvent under the catalytic action of 0.7mmol Nafion, and cyclohexane was used as the solvent. The reaction was carried out at 100℃ for 15h to study the recycling of Nafion. After the first reaction, the product and the catalyst will automatically separate into layers, with the upper layer being the product and the lower layer being the catalyst. The product is separated and the next cycle is continued. From the results in Table 2, it can be seen that the yield of Nafion is not significantly changed after four cycles, which indicates that the reaction system can be reused.

[0043] Table 2. Nafion circulation experiment

[0044]

[0045] The MS spectrum of the alkylation product obtained in Example 10 is as follows: Figure 1 As shown in the figure, it can be seen that the maximum mass-to-charge ratio of the molecular ion peak of the substance is m / z=230, while the molecular weight of turpentine is 136 and the theoretical molecular weight of phenolic compounds is 94, so the product is the target alkylation precursor.

[0046] The alkylation product obtained in Example 21 is separated by TLC or column chromatography to separate the different structures of the dimerization product, trimerization product and the product obtained by the participation of oxygen atoms in the polymerization reaction, and its specific structure is obtained by hydrogen nuclear magnetic resonance spectrum analysis.

[0047] The MS spectrum of the alkylation product obtained in Example 21 is as follows: Figure 2 As shown in the figure, it can be seen that the maximum mass-to-charge ratio of the molecular ion peak of the substance is m / z=324, while the molecular weight of turpentine is 136 and the theoretical molecular weight of phenolic compounds is 94, so the product is the target alkylation precursor.

[0048] The GC spectrum of the alkylation product obtained in Example 21 is as follows: Figure 3 As shown. The gas chromatograph set the injection port temperature to 280°C, the initial column box temperature to 60°C, the heating rate to 15°C / min, and the temperature was raised to 310°C and maintained for 5 minutes. It can be seen from the GC graph that under the catalysis of Nafion catalyst, the substance with a peak at 11 minutes is the product of the reaction in which oxygen atoms participate, the substance with a peak at 12-14 minutes is the alkylation dimerization product, and the substance with a peak at 18-20 minutes is the alkylation dimerization product.

[0049] Example 21 Alkylated dimerization addition product obtained 1 H-NMR spectrum Figure 4 shown. 1HNMR (600MHz, CDCl3) δ7.25–7.07(m,1H),6.93–6.63(m,2H),5.93–5.21(m,1H),2.85–1.51(m,7H),1.43–1.23(m,4H),1.22–0.65(m,7H).

[0050] Example 21 Alkylated trimerization product obtained 1 H-NMR spectrum Figure 5 As shown. 1HNMR (600MHz, CDCl3) δ 0.86 (d, J = 6.9 Hz, 1H), 0.78 (d, J = 6.9 Hz, 1H), 0.65 (d, J = 6.4 Hz, 1H).

[0051] Example 21 Alkylated dimerization addition product obtained 1 H-NMR spectrum Figure 6shown. 1HNMR (600MHz, CDCl3) δ7.50–6.61(m,5H),4.13–3.83(m,1H),1.89–1.84(m,1H),1.81–1.74(m,2H),1.68–1. 63(m,1H),1.40–1.34(m,1H),1.21–1.14(m,2H),1.08(d,J=17.0Hz,3H),1.01(d,J=5.4Hz,3H),0.90(s,3H).

[0052] Example 21 Alkylated dimerization addition product obtained 13 C-NMR spectrum Figure 7 As shown. 13C NMR (151MHz, CDCl3) δ157.98, 129.30, 119.97, 115.39, 84.40, 49.19, 47.02, 45.31, 39.54, 34.25, 27.41, 20.35, 20.14, 11.82.

[0053] The alkylation product obtained in Example 30 is separated by TLC or column chromatography to separate the different structures of the dimerization product and the trimerization product, and its specific structure is obtained by nuclear magnetic resonance hydrogen spectrum analysis.

[0054] The 1H-NMR spectrum of the alkylated trimerization product obtained in Example 30 is as follows: Figure 8 shown. 1HNMR (600MHz, CDCl3) δ7.20–7.10(m,1H),7.05(d,J=26.2Hz,1H),6.98(d,J=2.2Hz,1H),6.90(d,J=2.2Hz,1H),6.78–6.64(m,2H),5.05–4.90(m ,2H),2.32–2.23(m,6H),1.89(s,8H),1.34(s,1H),1.26(s,3H),1.13(s, 2H), 0.87 (d, J = 7.0Hz, 1H), 0.79 (d, J = 6.9Hz, 1H), 0.66 (d, J = 6.4Hz, 2H).

[0055] The 1H-NMR spectrum of the alkylated dimerization addition product obtained in Example 30 is as follows: Fig. 9 As shown. 1HNMR (600MHz, CDCl3) δ7.03–6.82 (m, 1H), 6.77–6.62 (m, 1H), 5.49–5.03 (m, 1H), 2.83–2.06 (m, 5H), 1.98–1.42 (m, 5H), 1.39–0.48 (m, 12H).

[0056] The 1H-NMR spectrum of the alkylated dimerization addition product obtained in Example 31 is as follows: Fig.10 As shown. 1H NMR (600MHz, CDCl3) δ7.25–7.07 (m, 1H), 6.83–6.57 (m, 2H), 5.08–4.64 (m, 1H), 2.44–2.25 (m, 4H), 1.96–1.27 (m, 8H), 1.20–0.83 (m, 8H).

[0057] Examples 41-63 are hydrodeoxygenation of the alkylation product obtained in Example 21, and the difference lies in the different catalysts, reaction temperatures, solvents, and reaction times in step S2. The specific parameters are shown in Table 3 below:

[0058] Table 3. Effects of catalyst, temperature, solvent and time on hydrogenation reaction

[0059]

[0060] From the results in Table 3, it can be seen that different metal catalysts have different hydrogenation capabilities. Among them, metal Rh and Pd have better activity. When screening solvents, it was found that toluene and cyclohexane both had good effects, but because cyclohexane still had a good effect in alkylation reactions, cyclohexane was used as the hydrogenation solvent. Then the temperature when using cyclohexane as a solvent for hydrogenation reactions was screened, and it was found that the yield was higher at 180°C, so the optimal conditions for the hydrogenation reaction were obtained.

[0061] Table 4. Hydrodeoxygenation cycle experiments

[0062]

[0063] The MS spectrum of the hydrogenation product obtained in Example 41 is as follows: Fig.11 As shown in the GC spectrum Fig.12 As shown. It can be seen from the figure that the maximum mass-to-charge ratio of the molecular ion peak of the substance is m / z=222, which is the molecular weight of the product obtained after the alkylation product is hydrodeoxygenated. The gas chromatograph sets the injection port temperature to 280°C, the initial column box temperature to 60°C, the heating rate to 15°C / min, and the temperature is raised to 310°C and maintained for 5 minutes. That is, the peak of the target biomass high-density fuel appears at around 11 minutes, and the peak of the hydrodeoxygenation product of the alkylation trimerization product appears at around 15 minutes.

[0064] The biomass high-density fuel obtained in Example 41 was compared with traditional petroleum-based fuels (JP-10, RJ-4, RJ-4-I, RJ-5, RJ-7) and it was found that while maintaining key properties such as density, calorific value, and freezing point, the difficulty and cost of synthesis were greatly reduced.

[0065] Table 5. Comparison of performance of different fuels

[0066]

[0067] As can be seen from Table 5, high-density aviation fuel can be prepared from turpentine by the two-step method. The density of the prepared high-density aviation fuel is 0.943 g / cm 3 The calorific value is 41.5MJ / Kg and the freezing point is -60℃. It is an aviation fuel with relatively good performance. The entire route uses biomass as raw material, which is a new green and environmentally friendly route and does not produce harmful substances.

[0068] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for preparing high-density aviation fuel from turpentine and phenolic compounds, characterized in that: The specific steps are: S1. Under the catalytic action of an acid catalyst, turpentine oil and a phenolic compound are added to a solvent in a molar ratio of 1:(0.8-1.2) to undergo an alkylation reaction to obtain an alkylated product having a bicyclic structure and a tricyclic structure; S2. Add the alkylation product prepared in step S1 into a solvent, and perform hydrodeoxygenation under the co-catalysis of Metal / C and a solid acid catalyst to generate a high-density aviation fuel.

2. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S1, the acid catalyst is one or more of p-toluenesulfonic acid, Nafion, T-62MP, Amberlyst15, Al-MCM-41, HPW / SiO2, HPW / MCM-41, D600, CD750, CD250, and SO4 / ZrO2-TiO2.

3. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S1, the ratio of the mass of the acid catalyst to the total mass of the phenolic compound and the turpentine oil is (0.01-0.5):1; the reaction temperature is 60-160° C., the reaction time is 9-21 h; and the substrate concentration is 10-15 mol / L.

4. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S1, the solvent is selected from one of propylene carbonate, toluene, cyclohexane, tetrahydrofuran, ethylene dichloride, dimethyl carbonate, n-octane and n-hexane.

5. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S1, the phenolic compound is one of o-cresol, p-cresol, m-cresol, xylenol, 4-ethylphenol, benzyl acetate, guaiacol, and phenol.

6. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S2, the Metal / C is one of Pd / C, Ru / C, and Rh / C; the solid acid catalyst is one of HY, H-Beta, H-MOR, and Al-MCM-41; and the mass ratio between the Metal / C and the solid acid catalyst is 1:(0.8-1.2).

7. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S2, the mass ratio between the amount of catalyst used and the alkylation product prepared in step S1 is (0.01-0.3):1; and the substrate concentration is 0.01-1 mol / L.

8. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S2, the hydrodeoxygenation reaction is carried out in a tank reactor; the temperature is 160-220°C, the reaction time is 6-14h, and the hydrogen pressure is 3-5MPa.

9. The method for preparing high-density aviation fuel from turpentine and phenolic compounds according to claim 1, characterized in that: In step S2, the solvent used is selected from one or more of cyclohexane, propylene carbonate, methanol, isopropanol, tridecane, toluene, tetrahydrofuran, N,N-dimethylformamide, n-hexane, ethyl acetate, and acetonitrile.

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