A high energy density aerospace fuel and a method of making the same

Abstract

The application discloses a high-energy-density aerospace fuel and a preparation method thereof. The fuel is prepared from the following components in percentage by mass: 60-90% of biomass-based polycyclic alkanes, 10-40% of coal and petroleum-based hydrocarbons, and 0-10% of additives. The biomass-based polycyclic alkanes are prepared from natural terpenes through polymerization and hydrogenation reaction. The preparation method comprises the following steps: adding the biomass-based polycyclic alkanes, the coal and petroleum-based hydrocarbons, and the additives into a container according to the proportioning, adding a solvent to mix the compounded fuel uniformly, and removing the solvent by rotary evaporation to obtain the fuel. The fuel obtained by optimizing the formula has the following characteristics: the density is greater than 0.96 g / mL, the heat value is higher than 43 MJ / kg, the freezing point is lower than -60 o C, and the renewable biomass fuel can replace the traditional petroleum-based high-energy-density fuel JP-10. The fuel not only has excellent energy density and low-temperature performance, but also realizes sustainable production of the fuel based on biomass resources.

Description

Technical Field

[0001] This invention relates to the field of organic compound synthesis technology, specifically to a high-energy-density aerospace fuel and its preparation method. Background Technology

[0002] High-energy-density aerospace fuels are a class of artificially synthesized liquid hydrocarbons designed to improve the flight performance of aerospace vehicles. Compared to conventional fuels, they possess advantages such as high density and high volumetric calorific value, effectively enhancing flight performance aspects such as range, speed, and payload. Traditional high-energy-density aerospace fuels are mostly prepared from coal- or petroleum-based compounds and their derivatives through Diels-Alder cycloaddition, hydrogenation, and isomerization reactions. Hanging tetrahydrodicyclopentadiene (JP-10) is the most widely used high-energy-density fuel, with a density of 0.936 g / mL, a calorific value of 42.3 MJ / kg, and a freezing point of -79°C. o C.

[0003] Terpenoids are widely available, and bicyclic monoterpenoids with bridged ring structures, such as α-pinene and β-pinene, are ideal raw materials for constructing high-performance, high-energy-density fuels. They can undergo polymerization addition reactions under acidic catalysts, and subsequent processing such as catalytic hydrogenation isomerization can yield biomass-based fuels. However, compared to traditional fuels like JP-10, terpenoid fuels have shortcomings in low-temperature performance; their freezing point rises with increasing density, their viscosity increases, and their low-temperature fluidity is insufficient. Therefore, developing a biomass-based high-energy-density fuel superior to JP-10 is of great significance. Fuel blending is an effective means of improving low-temperature properties while balancing density and calorific value. Summary of the Invention

[0004] The purpose of this invention is to provide a high-energy-density aerospace fuel and its preparation method. This method simplifies the preparation steps, improves the yield, and yields a fuel with a density greater than 0.96 g / mL, a calorific value exceeding 43 MJ / kg, and a freezing point below -60°C. o C can replace the traditional petroleum-based high-energy-density fuel JP-10.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A high-energy-density aerospace fuel is formulated from the following components by mass percentage: 60%-90% biomass-based polycyclic alkanes, 10%-40% coal and petroleum-based hydrocarbons, and 0%-10% additives; wherein the biomass-based polycyclic alkanes are obtained by polymerizing and hydrogenating natural terpenes sequentially.

[0007] Preferably, the natural terpene is one or more selected from α-pinene, β-pinene, limonene, carene, α-phellandrene, α-terpinene, γ-terpinene, camphene, terpinene, turpentine, eucalyptol, and eucalyptol.

[0008] Preferably, the coal and petroleum-based hydrocarbons are one or more of perhydrofluorene, perhydroacenaphthene, decahydronaphthalene, perhydrophenanthrene, and tetrahydrodicyclopentadiene.

[0009] Preferably, the additive is one or more of adamantane, dimethyladamantane, trimethyladamantane, tetramethyladamantane, tetracycloheptane, ethylene glycol dimethyl ether, and diethylene glycol monomethyl ether.

[0010] To achieve the above objectives, the present invention also provides a method for preparing the aforementioned high-energy-density space fuel, comprising the following steps:

[0011] S1. Preparation of biomass-based polycyclic alkanes. This step includes two reactions: natural terpenes are first polymerized under Lewis acid catalysis, followed by catalytic hydrogenation to obtain the desired product. The specific steps are as follows:

[0012] S1-1, Polymerization reaction: Natural terpenes and Lewis acid catalysts are added to the reaction tube, and self-condensation is carried out at a certain temperature for a period of time to generate C20 and C30 polymer products.

[0013] S1-2, Hydrogenation reaction: The polymerization product, solvent and hydrogenation catalyst prepared in step S1-1 are added to the reactor, and the hydrogenation reaction is carried out for a period of time under a certain reaction temperature and hydrogenation pressure to prepare biomass-based polycyclic alkanes.

[0014] S2. Add biomass-based polycyclic alkanes, coal and petroleum-based additives to the container according to the ratio, then add solvent to mix the compound fuel evenly, and remove the solvent by rotary evaporation to obtain biomass-based compound fuel, i.e., high energy density aerospace fuel.

[0015] Preferably, in step S1-1, the Lewis acid catalyst is selected from one or more of the following catalysts: AlCl3, FeCl3, Sc(OTf)3, Fe(OTf)3, Al(OTf)3, ZnCl2, Zn(OTf)2, FeCl2, CuCl, CeCl3, La(OTf)3; AlCl3 / [Bmim]Cl, AlCl3 / [Emim]Cl, AlCl3 / Urea; the mass ratio of the Lewis acid catalyst to the natural terpene is (0.01-0.5):1.

[0016] Further, in step S1-1, the solvent is dimethyl carbonate, propylene carbonate, toluene, cyclohexane, n-octane, tetrahydrofuran, dichloroethane, etc. N,NOne or more of dimethylformamides, wherein the mass-to-volume ratio of the substrate to the solvent is 1 g: 0.6 mL; the polymerization temperature is 25-120 °C. o C, the polymerization reaction time is 16 h.

[0017] Preferably, in steps S1-2, the hydrogenation catalyst is one of Pt / C, Pd / C, Ru / C, Ir / C, Rh / C, Co / C, Ni / C, Fe / C, Raney Ni, and Raney Co; the mass ratio between the hydrogenation catalyst and the polymerization product is (0.01:0.20):1.

[0018] Preferably, in steps S1-2, the solvent is one of ethyl acetate, ethanol, methanol, isopropanol, tetrahydrofuran, and 2-methyltetrahydrofuran, and the substrate concentration ranges from 0.1 to 30 mol / L; the hydrogenation reaction temperature is 60-220 °C, the hydrogenation reaction time is 3-24 h, and the hydrogen pressure is 1-6 MPa.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention, through compounding studies of products derived from the polymerization and hydrogenation of terpenoid compounds and optimization of the formulation, prepares a high-energy-density aerospace fuel with a density greater than 0.96 g / mL, a calorific value exceeding 43 MJ / kg, and a freezing point below -60°C. o C is a substitute for the traditional petroleum-based high-energy-density fuel JP-10. This fuel not only possesses excellent energy density and cryogenic performance, but also achieves sustainable fuel production based on biomass resources, providing a new technological solution for the green transformation of fuels in aerospace and other fields. Attached Figure Description

[0021] Figure 1 GC spectrum of the product prepared in Example 46;

[0022] Figure 2 GC spectrum of the product prepared in Example 51. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments.

[0024] In the following examples, unless otherwise stated, all reagents used are commercially available or obtained in accordance with known literature.

[0025] Examples 1-86

[0026] The preparation of biomass-based polycyclic alkanes involves two steps: natural terpenes are first polymerized under Lewis acid catalysis, followed by catalytic hydrogenation; the specific steps are as follows:

[0027] S1-1 Polymerization reaction: Terpenes such as α-pinene, β-pinene, limonene, camphene, terpinene, and turpentine undergo self-condensation under acid catalysis to generate C20 and C30 polymer products (effects of catalyst, solvent, time, and temperature). The reaction substrate (1.0 g, 7.3 mmol), solvent (0.6 mL), and 0.05 g of acid catalyst were added to a 35 mL reaction tube, and the reaction was carried out at a specific temperature for a specific time.

[0028] Table 1. Effects of catalyst, solvent, time, and temperature on polymerization reaction

[0029] Example raw material catalyst Time / h Temperature / ℃ solvent Dimer C20 yield / % Trimer C30 yield / % 1 α-pinene <![CDATA[FeCl3]]> 1 120 Toluene 3 2 2 α-pinene <![CDATA[Sc(OTf)3]]> 1 120 Toluene 60 3 3 α-pinene <![CDATA[La(OTf)3]]> 1 120 Toluene 5 0 4 α-pinene <![CDATA[CeCl3]]> 1 120 Toluene 7 0 5 α-pinene <![CDATA[ZnCl2]]> 1 120 Toluene 4 0 6 α-pinene CuCl 1 120 Toluene 5 0 7 α-pinene <![CDATA[FeCl2]]> 1 120 Toluene 8 0 8 α-pinene <![CDATA[AlCl3]]> 1 120 Toluene 63 22 9 α-pinene <![CDATA[Fe(OTf)3]]> 1 60 Toluene 3 0 10 α-pinene <![CDATA[Al(OTf)3]]> 1 60 Toluene 5 0 11 α-pinene <![CDATA[Zn(OTf)2]]> 1 60 Toluene 2 0 12 α-pinene <![CDATA[AlCl3]]> 1 50 Toluene 51 26 13 α-pinene <![CDATA[AlCl3]]> 1 60 Toluene 59 23 14 α-pinene <![CDATA[AlCl3]]> 1 70 Toluene 58 23 15 α-pinene <![CDATA[AlCl3]]> 1 80 Toluene 58 22 16 α-pinene <![CDATA[AlCl3]]> 1 90 Toluene 56 22 17 α-pinene <![CDATA[AlCl3]]> 1 100 Toluene 58 22 18 α-pinene <![CDATA[AlCl3]]> 1 110 Toluene 59 20 19 α-pinene <![CDATA[AlCl3]]> 6 25 Toluene 53 23 20 α-pinene <![CDATA[AlCl3]]> 3 40 Toluene 52 22 21 α-pinene <![CDATA[[Emim]Cl / AlCl3]]> 1 60 Toluene 43 21 22 α-pinene <![CDATA[[Emim]Cl / AlCl3]]> 3 60 Toluene 57 11 23 α-pinene <![CDATA[[Emim]Cl / AlCl3]]> 3 60 Solvent-free 58 10 24 α-pinene <![CDATA[[Emim]Cl / AlCl3]]> 2 80 Toluene 67 13 25 α-pinene <![CDATA[[Bmim]Cl / AlCl3]]> 3 60 Toluene 58 5 26 α-pinene <![CDATA[Urea / AlCl3]]> 2 80 Toluene 65 12 27 α-pinene <![CDATA[AlCl3]]> 1 60 DCE 48 27 28 α-pinene <![CDATA[AlCl3]]> 1 60 Cyclohexane 38 15 29 α-pinene <![CDATA[AlCl3]]> 1 60 n-Octane 15 8 30 α-pinene <![CDATA[AlCl3]]> 1 60 PC 76 13 31 α-pinene <![CDATA[AlCl3]]> 1 60 DMC 23 2 32 α-pinene <![CDATA[AlCl3]]> 1 60 THF 3 0 33 α-pinene <![CDATA[AlCl3]]> 1 60 DMF 5 2 34 α-pinene <![CDATA[AlCl3]]> 1 60 Solvent-free 24 12 35 β-pinene <![CDATA[AlCl3]]> 1 60 Toluene 5 0 36 α-Phragmitesin <![CDATA[AlCl3]]> 2 60 Toluene 25 5 37 α-Pine <![CDATA[AlCl3]]> 2 60 Toluene 75 7 38 Limonene <![CDATA[AlCl3]]> 2 60 Toluene 44 14 39 Camphene <![CDATA[AlCl3]]> 1.5 50 Toluene 39 24 40 γ-terpinene <![CDATA[AlCl3]]> 1.5 50 Toluene 65 9 41 carene <![CDATA[AlCl3]]> 1.5 50 Toluene 63 10 42 Terpinene <![CDATA[AlCl3]]> 1.5 50 Toluene 67 9 43 Eucalyptol <![CDATA[AlCl3]]> 1.5 50 Toluene 57 8 44 Eucalyptus oil <![CDATA[AlCl3]]> 1.5 50 Toluene 58 9 45 turpentine <![CDATA[AlCl3]]> 1 60 Toluene 45 17 46 turpentine <![CDATA[AlCl3]]> 2 60 Toluene 41 26 47 turpentine <![CDATA[AlCl3]]> 3 60 Toluene 47 16 48 turpentine <![CDATA[AlCl3]]> 4 60 Toluene 45 20 49 turpentine <![CDATA[AlCl3]]> 6 60 Toluene 47 16

[0030] As shown in Table 2, the strong Lewis acid AlCl3 can catalyze the reaction of the main components of turpentine oil, α-pinene, β-pinene, and limonene, at 60 °C. o The polymerization reaction was carried out at 80 °C, with a C20 dimer yield of 59% and a C30 trimer yield exceeding 20%. Screening of different solvents revealed that toluene, dichloromethane, and propylene carbonate showed relatively good performance for the reaction; however, toluene was chosen as the solvent from an environmental perspective. The effect of reaction time on the reaction was investigated using AlCl3 as the catalyst and toluene as the solvent. It was found that almost equivalent amounts of aviation fuel precursors were obtained in just 1 hour. However, AlCl3 as the catalyst cannot be recycled; therefore, the use of the ionic liquid [Emim]Cl / AlCl3 was studied using toluene as the solvent. Catalyzing the reaction of α-pinene at 80 °C for 2 hours resulted in a C20 dimer yield of 67% and a C30 trimer yield of 13%. After the first reaction, the product, insoluble in the highly polar ionic liquid, automatically separated into two phases: the upper layer was the product, and the lower layer contained the ionic liquid and catalyst. The product was separated, and α-pinene was added again for the next experiment. However, due to the significant decrease in catalytic effect caused by water absorption by the ionic liquid during the first reaction, this reaction system could not be repeated.

[0031] The GC spectrum of the product obtained in Example 46 is as follows. Figure 1 As shown in the GC diagram, turpentine oil underwent a polymerization reaction under acid catalysis, mainly producing polycyclic dimer products, accounting for more than 75% of the peak area, with a small amount of trimer products.

[0032] S1-2, Catalytic hydrogenation of terpene polymerization products to prepare biomass-based polycyclic alkanes (effects of solvent, catalyst, temperature, hydrogenation pressure, and reaction time). In a 50 mL reactor, due to the low price of turpentine, 15 g (55.1 mmol) of the terpene polymerization product prepared in Example 46 and 10 mL of ethyl acetate were added, followed by 150 mg of catalyst (5 wt% active metal loading). The reaction was carried out at a certain temperature and hydrogen pressure for a period of time to obtain biomass-based polycyclic alkanes.

[0033] Table 2. Effect of reaction conditions on hydrogenation reaction

[0034] Example solvent catalyst Temperature / °C Time / h Hydrogenation pressure / MPa High-density fuel yield / % 50 Ethyl acetate Pt / C 180 3 3.5 87 51 Ethyl acetate Pd / C 180 3 3.5 95 52 Ethyl acetate Ru / C 180 3 3.5 74 53 Ethyl acetate Ir / C 180 3 3.5 86 54 Ethyl acetate Rh / C 180 3 3.5 89 55 Ethyl acetate Co / C 180 3 3.5 87 56 Ethyl acetate Ni / C 180 3 3.5 88 57 Ethyl acetate Fe / C 180 3 3.5 86 58 Ethyl acetate Raney Ni 180 3 3.5 87 59 Ethyl acetate Raney Co 180 3 3.5 86 60 Ethyl acetate Pd / C 60 3 3.5 45 61 Ethyl acetate Pd / C 80 3 3.5 56 62 Ethyl acetate Pd / C 100 3 3.5 83 63 Ethyl acetate Pd / C 120 3 3.5 90 64 Ethyl acetate Pd / C 140 3 3.5 92 65 Ethyl acetate Pd / C 160 3 3.5 92 66 Ethyl acetate Pd / C 200 3 3.5 93 67 Ethyl acetate Pd / C 220 3 3.5 92 68 ethanol Pd / C 120 3 3.5 76 69 methanol Pd / C 120 3 3.5 69 70 Isopropanol Pd / C 120 3 3.5 71 71 Tetrahydrofuran Pd / C 120 3 3.5 78 72 2-Methyltetrahydrofuran Pd / C 120 3 3.5 83 73 Ethyl acetate Pd / C 180 1 3.5 76 74 Ethyl acetate Pd / C 180 2 3.5 83 75 Ethyl acetate Pd / C 180 6 3.5 95 76 Ethyl acetate Pd / C 180 9 3.5 94 77 Ethyl acetate Pd / C 180 12 3.5 95 78 Ethyl acetate Pd / C 180 15 3.5 95 79 Ethyl acetate Pd / C 180 18 3.5 95 80 Ethyl acetate Pd / C 180 24 3.5 96 81 Ethyl acetate Pd / C 180 3 1 67 82 Ethyl acetate Pd / C 180 3 2 80 83 Ethyl acetate Pd / C 180 3 3 92 84 Ethyl acetate Pd / C 180 3 4 93 85 Ethyl acetate Pd / C 180 3 5 93 86 Ethyl acetate Pd / C 180 3 6 95

[0035] As shown in Table 2, although the hydrogenation capabilities of different metal catalysts vary, they are all effective for the hydrogenation reaction of aviation fuel precursors. Among them, Pt and Pd exhibit the best activity, with product yields reaching 90%.

[0036] The GC spectrum of the product obtained in Example 51 is as follows. Figure 1 As shown in the GC diagram, under Pd / C catalysis, the turpentine polymerization product underwent complete hydrogenation. The dimerization hydrogenation product was still the main product, and no carbon-carbon bond breaking products were observed, indicating that polycyclic hydrocarbons are relatively stable and suitable for use as fuel.

[0037] Comparative Examples 1-3 and Examples 87-141

[0038] Preparation of high-energy-density aerospace fuels (the effects of coal and petroleum-based fuels, additives, and mass ratios)

[0039] In a 100 mL rotary evaporator flask, biomass-based polycyclic alkanes (60%-90%) synthesized from turpentine oil in Example 51, coal and petroleum-based compounds (10%-40%), and additives (0%-10%) were added in proportion. Then, 20 mL of solvent was added to mix the blended fuel thoroughly. The solvent was removed by rotary evaporation to obtain the biomass-based blended fuel. Density tests were then performed on the blended fuels with different proportions (20...). o C) Calorific value and freezing point tests, the results are shown in Table 3 below.

[0040] Table 3. Performance Comparison of High Energy Density Space Fuels

[0041] Serial Number Example 51 Synthesized Turpentine Fuel Coal and oil base additive Density (g / cm3) Calorific value (MJ / Kg) Freezing point (°C) Comparative Example 1 100% - - 0.9602 43.12 -51 Example 87 90% JP-10 (10%) - 0.9505 42.30 -65 Example 88 80% JP-10 (20%) - 0.9496 41.13 -72 Example 89 70% JP-10 (30%) - 0.9471 38.05 -70 Example 90 60% JP-10 (40%) - 0.9486 37.17 -68 Example 91 89% JP-10 (10%) Hydrochloride (1%) - 0.9506 38.55 -55 Example 92 85% JP-10 (10%) Hydrochloride (5%) - 0.9498 38.58 -59 Example 93 80% JP-10 (10%) 10% Hydroacenaphthene - 0.9491 37.97 -60 Example 94 79% JP-10 (20%) 1% Hydrochloride - 0.9495 38.64 -64 Example 95 75% JP-10 (20%) Hydrochloride (5%) - 0.9490 38.78 -65 Example 96 70% JP-10 (20%) 10% Hydrochloride - 0.9484 38.75 -65 Example 97 89.8% JP-10 (10%) Diethylene glycol monomethyl ether (0.2%) 0.9503 38.02 -64 Example 98 79.8% JP-10 (20%) Diethylene glycol monomethyl ether (0.2%) 0.9492 38.63 -70 Example 99 69.8% JP-10 (30%) Diethylene glycol monomethyl ether (0.2%) 0.9465 37.68 -68 Example 100 89.8% JP-10 (10%) Ethylene glycol dimethyl ether (0.2%) 0.9504 38.15 -60 Example 101 79.8% JP-10 (20%) Ethylene glycol dimethyl ether (0.2%) 0.9475 37.27 -70 Example 102 69.8% JP-10 (30%) Ethylene glycol dimethyl ether (0.2%) 0.9453 37.33 -79 Comparative Example 2 99.8% - Diethylene glycol monomethyl ether (0.2%) 0.9603 37.65 -54 Comparative Example 3 99.5% - Ethylene glycol dimethyl ether (0.5%) 0.9602 39.82 -55 Example 103 89% JP-10 (10%) 1% fluorene (1%) - 0.9501 38.78 -65 Example 104 79% JP-10 (20%) 1% fluorene - 0.9495 38.64 -70 Example 105 69% JP-10 (30%) 1% fluorene - 0.9468 38.00 -79 Example 106 80% JP-10 (10%) 10% fluorene - 0.9387 38.78 -60 Example 107 85% JP-10 (10%) fluorene (5%) - 0.9415 38.64 -72 Example 108 70% JP-10 (20%) 10% fluorene - 0.9334 37.34 -79 Example 109 75% JP-10 (20%) fluorene (5%) - 0.9398 37.23 -75 Example 110 60% JP-10 (30%) 10% fluorene - 0.9305 37.27 -79 Example 111 65% JP-10 (30%) fluorene (5%) - 0.9310 37.35 -80 Example 112 89% JP-10 (10%) 1% Hydrogenated Phenylephrine (1%) - 0.9516 38.52 -60 Example 113 85% JP-10 (10%) PHNPETERS (5%) - 0.9508 38.55 -62 Example 114 80% JP-10 (10%) 10% Hydrogen Phenylephrine (10%) - 0.9501 37.92 -65 Example 115 89% JP-10 (10%) decahydronaphthalene (1%) - 0.9233 38.79 -58 Example 116 85% JP-10 (10%) decahydronaphthalene (5%) - 0.9229 38.84 -62 Example 117 80% JP-10 (10%) decahydronaphthalene (10%) - 0.9219 38.97 -72 Example 118 93% JP-10 (2%) adamantane (5%) 0.9654 44.12 -52 Example 119 85% JP-10 (5%) Adamantane (10%) 0.9647 44.38 -55 Example 120 92.5% JP-10 (2.5%) adamantane (5%) 0.9643 44.18 -50 Example 121 85% JP-10 (5%) Adamantane (10%) 0.9608 44.38 -61 Example 122 90% JP-10 (5%) adamantane (5%) 0.9665 44.21 -67 Example 123 85% JP-10 (10%) adamantane (5%) 0.9570 44.13 -69 Example 124 80% JP-10 (20%) Adamantane (2%) 0.9513 43.10 -72 Example 125 65% JP-10 (30%) adamantane (5%) 0.9509 43.07 -78 Example 126 60% JP-10 (33%) adamantane (7%) 0.9597 43.04 -79 Example 127 60% JP-10 (32%) adamantane (8%) 0.9614 43.22 -73 Example 128 60% JP-10 (34%) adamantane (6%) 0.9544 43.02 -79 Example 129 70% JP-10 (25%) adamantane (5%) 0.9560 43.34 -70 Example 130 67% JP-10 (25%) adamantane (8%) 0.9627 43.82 -75 Example 131 69% JP-10 (25%) adamantane (6%) 0.9595 43.64 -70 Example 132 68.5% JP-10 (25%) adamantane (6.5%) 0.9592 43.70 -71 Example 133 68% JP-10 (25%) adamantane (7%) 0.9593 43.76 -74 Example 134 76% JP-10 (20%) adamantane (4%) 0.9581 43.21 -62 Example 135 75% JP-10 (20%) adamantane (5%) 0.9590 43.25 -65 Example 136 74.5% JP-10 (20%) adamantane (5.5%) 0.9602 43.31 -70 Example 137 74% JP-10 (20%) adamantane (6%) 0.9605 43.21 -70 Example 138 74% JP-10 (20%) Dimethyladamantane (6%) 0.9531 43.13 -68 Example 139 74% JP-10 (20%) Trimethyladamantane (6%) 0.9482 43.27 -65 Example 140 74% JP-10 (20%) Tetramethyladamantane (6%) 0.9396 43.32 -70 Example 141 74% JP-10 (20%) Tetracycloheptaane (6%) 0.9603 43.35 -60

[0042] As can be seen from the above examples and comparative examples, the density of biomass-based polycyclic alkanes obtained directly from turpentine oil in Comparative Example 1 is 0.9602 g / cm³. 3Its calorific value is 43.12 MJ / kg, and its freezing point is -51 °C, which is significantly lower than that of petroleum-based fuel JP-10. By blending biomass-based polycyclic alkanes, coal, petroleum-based fuels, and additives in specific mass ratios, fuels with different performance requirements can be obtained according to different proportions, and the fuel density can exceed 0.96 g / cm³. 3 It has a freezing point below -60 °C and a calorific value above 43 MJ / kg. Table 3 shows that in Example 137, a high-density, low-freezing-point fuel was obtained by blending turpentine fuel (74%), JP-10 (20%), and adamantane (6%) synthesized in Example 51, with a fuel density of 0.9605 g / cm³. 3 With a calorific value of 43.21 MJ / kg and a freezing point of -70 °C, its overall performance is superior to that of petroleum-based fuel JP-10.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-energy-density space fuel, characterized in that, It is formulated from the following components by mass percentage: 60%-90% biomass-based polycyclic alkanes, 10%-40% coal and petroleum-based hydrocarbons, and 0%-10% additives; the biomass-based polycyclic alkanes are obtained by polymerizing and hydrogenating natural terpenes sequentially; the additives are one or more of adamantane, dimethyl adamantane, trimethyl adamantane, tetramethyl adamantane, tetracycloheptane, ethylene glycol dimethyl ether, and diethylene glycol monomethyl ether; the coal and petroleum-based hydrocarbons are one or more of perhydrofluorene, perhydroacenaphthene, decahydronaphthalene, perhydrophenanthrene, and tetrahydrodicyclopentadiene; the high-energy-density aerospace fuel has a density greater than 0.96 g / mL at 20℃, a calorific value exceeding 43 MJ / kg, and a freezing point below -60℃; The method for preparing the high-energy-density space fuel includes the following steps: S1. Preparation of biomass-based polycyclic alkanes. This step includes two reactions: natural terpenes are first polymerized under Lewis acid catalysis, followed by catalytic hydrogenation to obtain the desired product. The specific steps are as follows: S1-1, Polymerization reaction: Natural terpenes and Lewis acid catalysts are added to the reaction tube, and self-condensation is carried out at a certain temperature for a period of time to generate C20 and C30 polymerization products; the Lewis acid catalyst is selected from one or more of the following catalysts: AlCl3, FeCl3, Sc(OTf)3, Fe(OTf)3, Al(OTf)3, ZnCl2, Zn(OTf)2, FeCl2, CuCl, CeCl3, La(OTf)3, AlCl3 / [Bmim]Cl, AlCl3 / [Emim]Cl or AlCl3 / Urea; the mass ratio of the Lewis acid catalyst to the natural terpenes is (0.01-0.5):1; S1-2, Hydrogenation reaction: The polymerization product, solvent, and hydrogenation catalyst prepared in step S1-1 are added to a reactor, and hydrogenation reaction is carried out for a period of time under a certain reaction temperature and hydrogenation pressure to prepare biomass-based polycyclic alkanes; the hydrogenation catalyst is one of Pt / C, Pd / C, Ru / C, Ir / C, Rh / C, Co / C, Ni / C, Fe / C, Raney Ni, or Raney Co; the mass ratio of the hydrogenation catalyst to the polymerization product is (0.01-0.20):1; S2. Add biomass-based polycyclic alkanes, coal and petroleum-based hydrocarbons, and additives to the container according to the ratio, then add solvent to mix the compound fuel evenly, and remove the solvent by rotary evaporation to obtain biomass-based compound fuel, i.e., high-energy-density aerospace fuel.

2. The high-energy-density space fuel according to claim 1, characterized in that, The natural terpenes are one or more of α-pinene, β-pinene, limonene, carene, α-phellandrene, α-terpinene, γ-terpinene, camphene, and terpinene.

3. The high-energy-density space fuel according to claim 1, characterized in that, The natural terpenes are turpentine oil and / or eucalyptus oil.

4. A method for preparing a high-energy-density aerospace fuel as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Preparation of biomass-based polycyclic alkanes. This step includes two reactions: natural terpenes are first polymerized under Lewis acid catalysis, followed by catalytic hydrogenation to obtain the desired product. The specific steps are as follows: S1-1, Polymerization reaction: Natural terpenes and Lewis acid catalysts are added to the reaction tube, and self-condensation is carried out at a certain temperature for a period of time to generate C20 and C30 polymerization products; the Lewis acid catalyst is selected from one or more of the following catalysts: AlCl3, FeCl3, Sc(OTf)3, Fe(OTf)3, Al(OTf)3, ZnCl2, Zn(OTf)2, FeCl2, CuCl, CeCl3, La(OTf)3, AlCl3 / [Bmim]Cl, AlCl3 / [Emim]Cl or AlCl3 / Urea; the mass ratio of the Lewis acid catalyst to the natural terpenes is (0.01-0.5):1; S1-2, Hydrogenation reaction: The polymerization product, solvent, and hydrogenation catalyst prepared in step S1-1 are added to a reactor, and hydrogenation reaction is carried out for a period of time under a certain reaction temperature and hydrogenation pressure to prepare biomass-based polycyclic alkanes; the hydrogenation catalyst is one of Pt / C, Pd / C, Ru / C, Ir / C, Rh / C, Co / C, Ni / C, Fe / C, Raney Ni, or Raney Co; the mass ratio of the hydrogenation catalyst to the polymerization product is (0.01-0.20):1; S2. Add biomass-based polycyclic alkanes, coal and petroleum-based hydrocarbons, and additives to the container according to the ratio, then add solvent to mix the compound fuel evenly, and remove the solvent by rotary evaporation to obtain biomass-based compound fuel, i.e., high-energy-density aerospace fuel.

5. The method for preparing a high-energy-density aerospace fuel according to claim 4, characterized in that, In step S1-1, a solvent is also added, wherein the solvent is dimethyl carbonate, propylene carbonate, toluene, cyclohexane, n-octane, tetrahydrofuran, dichloroethane, etc. N,N One or more of dimethylformamides are used, with a mass-to-volume ratio of 1 g to 0.6 mL between the substrate and the solvent; the polymerization temperature is 25-120 °C, and the polymerization time is 1-6 h.

6. The method for preparing a high-energy-density aerospace fuel according to claim 4, characterized in that, In steps S1-2, the solvent used is one of ethyl acetate, ethanol, methanol, isopropanol, tetrahydrofuran, or 2-methyltetrahydrofuran, and the substrate concentration ranges from 0.1 to 30 mol / L; the hydrogenation reaction temperature is 60-220℃, the hydrogenation reaction time is 3-24 h, and the hydrogen pressure is 1-6 MPa.

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