Biomass spiral hydrocarbon fuel and preparation method thereof

Abstract

The present invention discloses a biomass spirocyclic hydrocarbon fuel and a preparation method thereof. Cyclopentanone / cyclohexanone dissolved in a solvent is added dropwise to a low-valent titanium reagent, and then transferred to an oil bath to undergo a McMurry reaction to generate an olefin with an intercyclic double bond, with a product yield of not less than 95%; (2) a homogeneous / heterogeneous acid-catalyzed cyclopropanation reaction: an olefin with an intercyclic double bond dissolved in a solvent is slowly added to a reaction system containing a carbene body, a cyclopropanation reaction occurs, and the reaction is terminated to obtain a novel biomass spirocyclic hydrocarbon fuel, with a product yield of not less than 95%. The present invention uses biomass as raw material to prepare liquid hydrocarbon fuel, which can not only expand the source of raw materials and ensure energy supply security, but also achieve efficient utilization of biomass and improve economic benefits. The calorific value is increased by about 25% compared to traditional fuels (35MJ / L), and under the same other conditions, the endurance or load of an aircraft can be increased by about 25%. The freezing point is not higher than -70°C, which can ensure the safety of aircraft in high-altitude and low-temperature flight.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass fuels, and in particular to a biomass spiral hydrocarbon fuel and a preparation method thereof. Background Art

[0002] The aviation sector is a core area related to national defense and security, and is also an important manifestation of a country's scientific and technological level and comprehensive strength. Liquid hydrocarbon fuel is the power source of aviation propulsion systems and is widely used in engines such as turbojets, ramjets, rockets, and combined propulsion systems. As aircraft flight speeds and airspace continue to increase, higher requirements are placed on fuel performance. Fuel energy is a key factor in determining aircraft performance. Increasing the volumetric calorific value of fuel can increase the energy carried by the aircraft, increase the aircraft's range / range and payload, or reduce the aircraft's size, while maintaining a certain fuel tank volume, thereby improving maneuverability and penetration capabilities. The volumetric calorific value of fuel is equal to the product of its density and mass calorific value. Therefore, increasing fuel density and mass calorific value is the key to increasing fuel energy.

[0003] Lignocellulose is the most abundant renewable biomass resource on Earth, composed of cellulose (30-50%), hemicellulose (20-40%), and lignin (10-20%). Catalytic cracking can produce a variety of platform compounds, such as ketones, alcohols, and furans. Cyclopentanone, a typical biomass platform compound, can be produced through catalytic hydrogenation of furfural, a hemicellulose derivative. Furthermore, lignin produces different product distributions under different depolymerization methods and can be converted into compounds such as cyclohexanones, cyclohexanols, and cycloalkanes through selective hydrogenation. Cyclohexanone and its derivatives are very important chemicals, currently produced primarily through the oxidation of cyclohexane or alkylcyclohexanes and the selective hydrogenation of phenol. Importantly, industrial production of cyclopentanone and cyclohexanone has already been achieved. However, existing biomass fuel molecules are mostly chain alkanes or five- or six-membered ring structures, which greatly limits their calorific value and cannot meet the requirements of future aircraft.

[0004] Therefore, making full use of lignocellulosic platform compounds to design and synthesize biomass fuels with high energy density has become one of the bottleneck problems that need to be broken through in the development of high-performance aviation fuels. It can not only enrich the types of high-energy-density aviation fuels but also provide theoretical and technical support for the green and multi-pathway preparation of aviation fuels. Summary of the Invention

[0005] In view of the above shortcomings, the present invention provides a biomass spirocyclic hydrocarbon fuel and its preparation method, which fully utilizes lignocellulosic platform compounds to design and synthesize biomass fuel with high energy density. The present invention is achieved through the following technical means:

[0006] The present invention discloses a novel biomass spiral hydrocarbon fuel, the structural formula of which is as follows:

[0007]

[0008] The present invention also provides a method for preparing the novel biomass spirocyclic hydrocarbon fuel, comprising:

[0009] (1) McMurry reaction:

[0010] Take cyclopentanone / cyclohexanone dissolved in solvent and add it dropwise to low-valent titanium reagent, and at the same time transfer it into oil bath to cause McMurry reaction to generate olefins with intercyclic double bonds (such as Figure 1 The product yield is not less than 95%;

[0011] (2) Homogeneous / heterogeneous acid-catalyzed cyclopropanation reaction:

[0012] An olefin with an intercyclic double bond dissolved in a solvent is slowly added to a reaction system containing a carbene body to cause a cyclopropanation reaction. After the reaction is completed, a new type of biomass spirocyclic hydrocarbon fuel (such as Figure 1 The product yield is not less than 95%.

[0013] Furthermore, the low-valent titanium reagent in step (1) is prepared by the following method:

[0014] Titanium trichloride or titanium tetrachloride is slowly added into a solvent suspension containing a metal or its hydride, and stirred at room temperature under nitrogen protection to form a low-valent titanium reagent.

[0015] Furthermore, the substance containing metal or its hydride includes but is not limited to:

[0016] Zn, Zn-Cu, Mg, LiAlH4.

[0017] Furthermore, the solvent suspension includes but is not limited to:

[0018] Diethyl ether, tetrahydrofuran, acetonitrile, methanol.

[0019] Furthermore, the McMurry reaction conditions in step (1) are:

[0020] Reaction temperature: -70~70℃, reaction time: 0.5~30h.

[0021] Furthermore, the solvent in step (2) comprises:

[0022] Diethyl ether, tetrahydrofuran, n-hexane, 1,4-dioxane, 1,2-dimethoxyethane, dichloromethane.

[0023] Furthermore, the carbene in step (2) is prepared by the following method:

[0024] A homogeneous / heterogeneous acid catalyst is added to a solvent containing an organometallic reagent and stirred under nitrogen protection. Subsequently, diiodomethane or chloroiodomethane or bromoiodomethane dissolved in the solvent is added dropwise to the reaction system to form a carbene.

[0025] Furthermore, the homogeneous / heterogeneous acid catalyst includes but is not limited to:

[0026] Trifluoroacetic acid, acidic molecular sieves (HY, Hbeta, HZSM-5), phosphotungstic acid (HPW), phosphotungstic acid-loaded molecular sieves (HPW / HY, HPW / Hbeta, HPW / HZSM-5), phosphotungstic acid-loaded MOFs (HPW / MOFs), and phosphotungstic acid-loaded carbon nanotubes.

[0027] Furthermore, in the solvent containing the organometallic reagent, wherein:

[0028] Base metals include: diethylzinc, triethylaluminum;

[0029] Solvents include: carbon tetrachloride, toluene, 1,2-dichloroethane, dichloromethane, diethyl ether, and tetrahydrofuran.

[0030] Furthermore, the solvent is dissolved in diiodomethane, chloroiodomethane or bromoiodomethane:

[0031] Solvents include: diethyl ether, tetrahydrofuran, n-hexane, 1,4-dioxane, 1,2-dimethoxyethane, and dichloromethane.

[0032] Furthermore, the cyclopropanation reaction conditions in step (2) are:

[0033] Reaction temperature: -70~70℃, reaction time: 0.5~30h.

[0034] The present invention also discloses a novel biomass spiral hydrocarbon fuel prepared according to any one of the above preparation methods.

[0035] The beneficial effects of the present invention are:

[0036] 1. The present invention uses biomass as raw material to prepare liquid hydrocarbon fuel, which can not only expand the source of raw materials and ensure the security of energy supply, but also realize the efficient utilization of biomass and improve economic benefits.

[0037] 2. The calorific value is increased by about 25% compared to traditional fuel (35MJ / L). Under the same conditions, the aircraft's endurance or payload can be increased by about 25%.

[0038] 3. The freezing point is no higher than -70℃, which can ensure the safety of the aircraft flying at high altitude and low temperature.

[0039] 4. The thermal stability temperature is not less than 450℃, and the heat sink at 760℃ is not less than 4.0MJ / kg, which can ensure that the hypersonic aircraft can operate stably for a long time under high Mach number conditions. This will provide fuel power reserves for the design and development of new engines such as ramjet engines, turbine-ramjet, rocket-ramjet combined power for hypersonic flight, and the development of new aerospace systems.

[0040] 5. The minimum ignition temperature is no higher than 300℃, which can ensure normal ignition under extreme conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a synthetic pathway diagram for biomass hydrocarbon spirocyclic fuels. DETAILED DESCRIPTION

[0042] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0043] A biomass spiral hydrocarbon fuel and a preparation method thereof, comprising

[0044] (1) McMurry reaction: The synthesis is carried out in a three-necked flask. First, titanium trichloride or titanium tetrachloride is slowly added to a suspension of a metal or its hydride (Zn, Zn-Cu, Mg, LiAlH4) in a solvent (ether, tetrahydrofuran, acetonitrile, methanol), and stirred at room temperature under nitrogen protection to form a low-valent titanium reagent. Subsequently, cyclopentanone / cyclohexanone dissolved in the solvent is added dropwise to the reaction solution, which is simultaneously transferred to an oil bath. The reaction temperature is -70 to 70°C, and the reaction time is 0.5 to 30 hours. The McMurry reaction occurs to produce olefins (1-1, 2-1, 3-1) with an intercyclic double bond. The yield of the target product is not less than 95%.

[0045] (2) Homogeneous / heterogeneous acid-catalyzed cyclopropanation reaction:

[0046] First, a homogeneous / heterogeneous acid catalyst is added to a solvent (carbon tetrachloride, toluene, 1,2-dichloroethane, dichloromethane, diethyl ether, tetrahydrofuran) containing an organometallic reagent (diethylzinc, triethylaluminum) and stirred under nitrogen. Diiodomethane (or chloroiodomethane or bromoiodomethane) dissolved in the solvent is then added dropwise to the reaction system to form a carbene. Finally, an olefin precursor (1-1, 2-1, 3-1) dissolved in the solvent is slowly added to the reaction system. The reaction temperature is -70 to 70°C and the reaction time is 0.5 to 30 hours. A cyclopropanation reaction occurs to produce the dispirocyclopropane fuel (1-2, 2-2, 3-2), with a yield of at least 95%. Among them, homogeneous / heterogeneous acid catalysts include but are not limited to: trifluoroacetic acid, acidic molecular sieves (HY, Hbeta, HZSM-5), phosphotungstic acid (HPW), phosphotungstic acid-supported molecular sieves (HPW / HY, HPW / Hbeta, HPW / HZSM-5), phosphotungstic acid-supported MOFs (HPW / MOFs), phosphotungstic acid-supported carbon nanotubes, etc.

[0047] Examples 1 to 5 are now prepared by selecting the corresponding reaction raw materials and reaction parameters according to the relevant requirements in the table, which include two reaction steps, wherein the relevant parameters selected in step (1) are shown in Table 1, and the relevant parameters selected in step (2) are shown in Table 2:

[0048] Table 1 Related parameters selected in step (1) of Examples 1 to 5

[0049]

[0050] Table 2 Related parameters selected in step (2) of Examples 1 to 5

[0051]

[0052]

[0053] Table 3 Fuel performance parameters of Examples 1 to 3

[0054]

Claims

1. A method for preparing a biomass spirocyclic hydrocarbon fuel, comprising: Step (1) is the McMurry reaction: Cyclopentanone and / or cyclohexanone dissolved in a solvent is added dropwise to a low-valent titanium reagent, and the mixture is simultaneously placed in an oil bath to undergo a McMurry reaction to generate an olefin with an intercyclic double bond, with a product yield of not less than 95%; Step (2) is a homogeneous / heterogeneous acid-catalyzed cyclopropanation reaction: An olefin having an intercyclic double bond dissolved in a solvent is slowly added to a reaction system containing a carbene to cause a cyclopropanation reaction. Upon completion of the reaction, a biomass spirocyclic hydrocarbon fuel is obtained, with a product yield of not less than 95%; Wherein: The structural formula of the biomass spirocyclic hydrocarbon fuel is as follows: 。 2. The preparation method according to claim 1, wherein: The low-valent titanium reagent in step (1) is prepared by the following method: Titanium trichloride or titanium tetrachloride is slowly added into a solvent suspension containing a metal or its hydride, and stirred at room temperature under nitrogen protection to form a low-valent titanium reagent.

3. The preparation method according to claim 2, wherein: The substance containing metal or its hydride includes: Zn, Mg or LiAlH4; The solvent suspension includes: diethyl ether, tetrahydrofuran, acetonitrile or methanol.

4. The preparation method according to claim 2, wherein: The substance containing metal or its hydride includes: Zn-Cu.

5. The preparation method according to claim 1, wherein: The McMurry reaction conditions in step (1) are: Reaction temperature: -70~70℃, reaction time: 0.5~30 h.

6. The preparation method according to claim 1, wherein: The solvent in step (2) includes: Diethyl ether, tetrahydrofuran, n-hexane, 1,4-dioxane, 1,2-dimethoxyethane, or dichloromethane; The carbene in step (2) is prepared by the following method: A homogeneous / heterogeneous acid catalyst is added to a solvent containing an organometallic reagent and stirred under nitrogen protection. Subsequently, diiodomethane or chloroiodomethane or bromoiodomethane dissolved in the solvent is added dropwise to the reaction system to form a carbene.

7. The preparation method according to claim 6, wherein: The homogeneous / heterogeneous acid catalyst comprises: Trifluoroacetic acid, acidic molecular sieves, phosphotungstic acid (HPW), phosphotungstic acid-supported molecular sieves, phosphotungstic acid-supported MOFs (HPW / MOFs), or phosphotungstic acid-supported carbon nanotubes; In the solvent containing the organometallic reagent: Organometallics include: diethylzinc or triethylaluminum; Solvents include: carbon tetrachloride, toluene, 1,2-dichloroethane, dichloromethane, diethyl ether, or tetrahydrofuran; Said solution is in diiodomethane or chloroiodomethane or bromoiodomethane of the solvent: Solvents include: diethyl ether, tetrahydrofuran, n-hexane, 1,4-dioxane, 1,2-dimethoxyethane or dichloromethane.

8. The preparation method according to claim 7, wherein: The acidic molecules are selected from any one of HY, Hbeta, and HZSM-5; The molecular sieve of the phosphotungstic acid loading is selected from any one of HPW / HY, HPW / Hbeta and HPW / HZSM-5.

9. The preparation method according to claim 1, wherein: The cyclopropanation reaction conditions in step (2) are: Reaction temperature: -70~70℃, reaction time: 0.5~30 h.

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