A water / hydrocarbon fuel emulsion gel and its preparation method

Abstract

The present invention belongs to the technical field of hydrocarbon fuels, and particularly relates to a water / hydrocarbon fuel emulsion gel and a preparation method thereof. The water / hydrocarbon fuel emulsion gel provided by the present invention comprises water, a hydrocarbon fuel, a non-ionic surfactant, and a gel factor; the gel factor comprises N-alkyl-N'-(hydroxyalkyl)-urea and / or alkyl alkylcarbamate; the N-alkyl-N'-(hydroxyalkyl)-urea has the structure shown in Formula I, and the alkyl alkylcarbamate has the structure shown in Formula II. When the water / hydrocarbon fuel emulsion gel provided by the present invention is used, it can slow down the damage to the emulsion structure under high centrifugal force conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrocarbon fuels, and particularly relates to a water / hydrocarbon fuel emulsion gel and a preparation method thereof. Background Art

[0002] Hypersonic flight technology is a new high point in the development of aerospace technology in the 21st century, and it is also one of the key core technologies in the current aerospace and national defense fields (such as tactical missiles). During the hypersonic flight of an aircraft, a large amount of aerodynamic heat is generated due to the intense friction between the aircraft and the air, causing the temperature of the aircraft subsystems to rise rapidly. At this time, a coolant is required to actively cool the high-temperature subsystems. In a hypersonic aircraft, an endothermic hydrocarbon fuel is used as both a propellant and a coolant. This requires the endothermic hydrocarbon fuel to have good endothermic capacity.

[0003] The steam catalytic reforming reaction of hydrocarbon fuels refers to the reaction of hydrocarbon fuels with steam under high-temperature catalysis to produce hydrogen, carbon monoxide, carbon dioxide, and small hydrocarbon substances. This reaction is a strong endothermic reaction and can significantly improve the endothermic capacity of the fuel. To improve the steam reforming efficiency of hydrocarbon fuels, it is necessary to ensure the uniform dispersion of water in the hydrocarbon fuel. The prior art prepares water and hydrocarbon fuel into an emulsion, which can solve this problem to a certain extent. However, the high-speed flight of the aircraft will accelerate the destruction of the emulsion system. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a water / hydrocarbon fuel emulsion gel and a preparation method thereof. When the water / hydrocarbon fuel emulsion gel provided by the present invention is used, it can slow down the destruction of the emulsion structure under high centrifugal force conditions.

[0005] To achieve the above purpose, the present invention provides a water / hydrocarbon fuel emulsion gel, which includes water, hydrocarbon fuel, a non-ionic surfactant, and a gel factor;

[0006] The gel factor includes N-alkyl-N'-(hydroxyalkyl)-urea and / or alkyl alkylcarbamate;

[0007] The N-alkyl-N'-(hydroxyalkyl)-urea has the structure shown in Formula I:

[0008] In Formula I, the range of n is 2 to 7;

[0009] The alkyl alkylcarbamate has the structure shown in Formula II:

[0010] In Formula II, the range of n is 2 to 7; R and R1 are independently alkyl; the number of carbon atoms of the alkyl is 1 to 12.

[0011] Preferably, the mass ratio of the water to the hydrocarbon fuel is 5-50:50-95; the mass of the gel factor is 0.5-10% of the total mass of the water, the hydrocarbon fuel and the nonionic surfactant.

[0012] Preferably, the nonionic surfactant includes Span 80 and Tween 80; Span 80 is 0.01-2% of the mass of the water; Tween 80 is 0.01-2% of the mass of the hydrocarbon fuel.

[0013] Preferably, the hydrocarbon fuel includes one or more of norbornane, alkanes with ≥8 carbon atoms, cyclohexane compounds, benzene compounds, and naphthalene compounds.

[0014] Preferably, the cyclohexane compounds include cyclohexane and / or alkyl-substituted cyclohexane.

[0015] Preferably, the naphthalene compounds include one or more of tetralin, decalin, alkyl-substituted tetralin, and alkyl-substituted decalin.

[0016] The present invention also provides a preparation method of the water / hydrocarbon fuel emulsion gel described above, comprising the following steps: mixing water, hydrocarbon fuel, nonionic surfactant, and gel factor, and then heating to obtain the water / hydrocarbon fuel emulsion gel.

[0017] Preferably, the mixing is to first mix water, hydrocarbon fuel, and nonionic surfactant to obtain an emulsion;

[0018] then secondarily mix the emulsion with the gel factor.

[0019] Preferably, the first mixing method is high-speed shearing; the frequency of the high-speed shearing is 10000-20000 Hz, and the time is 5-15 min.

[0020] Preferably, the heating temperature is 75-85 °C, and the time is 5-30 min.

[0021] The present invention provides a water / hydrocarbon fuel emulsion gel, comprising water, hydrocarbon fuel, nonionic surfactant, and gel factor; the gel factor includes N-alkyl-N'-(hydroxyalkyl)-urea and / or alkyl carbamate alkyl urethane; the N-alkyl-N'-(hydroxyalkyl)-urea has the structure shown in Formula I, and the alkyl carbamate alkyl urethane has the structure shown in Formula II. The present invention transforms the fluid water / hydrocarbon fuel emulsion into a thixotropic emulsion gel that is solid at rest and liquid under shear force, binding the movement of liquid molecules in the solid state and resisting the destruction of the emulsion structure by centrifugal force. Description of the Drawings

[0022] Figure 1 Rheological property test chart of the product prepared in Example 1;

[0023] Figure 2 Rheological property test chart of the product prepared in Example 2;

[0024] Figure 3 Rheological property test chart of the product prepared in Example 3;

[0025] Figure 4 Rheological property test chart of the product prepared in Example 4;

[0026] Figure 5 High centrifugal force test result chart of the products prepared in Example 2 and Comparative Example 1. Detailed implementation manners

[0027] The present invention provides a water / hydrocarbon fuel emulsion gel, comprising water, a hydrocarbon fuel, a non-ionic surfactant, and a gelling agent;

[0028] The gelling agent comprises N-alkyl-N'-(hydroxyalkyl)-urea and / or alkyl alkylcarbamate;

[0029] The N-alkyl-N'-(hydroxyalkyl)-urea has the structure shown in Formula I:

[0030] In Formula I, the range of n is 2 to 7;

[0031] The alkyl alkylcarbamate has the structure shown in Formula II:

[0032] In Formula II, the range of n is 2 to 7; R and R1 are independently alkyl; the number of carbon atoms of the alkyl is 1 to 12.

[0033] In the present invention, the water / hydrocarbon fuel emulsion gel comprises water, a hydrocarbon fuel, a non-ionic surfactant, and a gelling agent.

[0034] In the present invention, the hydrocarbon fuel preferably includes one or more of norbornane tetrahydrodicyclopentadiene (JP-10), alkanes with carbon atom number ≥8, cyclohexane compounds, benzene compounds, and naphthalene compounds. In the present invention, the number of carbon atoms in the alkanes is preferably 8-16, more preferably 10-12. In the present invention, the cyclohexane compounds preferably include cyclohexane and / or alkyl-substituted cyclohexane; the alkyl-substituted cyclohexane is preferably methylcyclohexane, ethylcyclohexane, propylcyclohexane, isopropylcyclohexane, butylcyclohexane, or cyclohexylcyclohexane. In the present invention, the benzene compounds preferably include benzene and / or alkyl-substituted benzene; the alkyl-substituted benzene is preferably toluene or ethylbenzene. In the present invention, the naphthalene compounds preferably include one or more of tetrahydronaphthalene, decahydronaphthalene, alkyl-substituted tetrahydronaphthalene, and alkyl-substituted decahydronaphthalene.

[0035] In the present invention, the mass ratio of the water to the hydrocarbon fuel is preferably 5-50:50-95, more preferably 5-20:80-95.

[0036] In the present invention, the non-ionic surfactant preferably includes Span 80 and Tween 80. In the present invention, Span 80 is preferably 0.01-2% of the mass of the water, more preferably 0.05-1%; Tween 80 is 0.01-2% of the mass of the hydrocarbon fuel, more preferably 0.05-1%.

[0037] In the present invention, the gel factor includes N-alkyl-N'-(hydroxyalkyl)-urea and / or alkyl carbamate alkyl ester, preferably N-alkyl-N'-(hydroxyalkyl)-urea.

[0038] In the present invention, the N-alkyl-N'-(hydroxyalkyl)-urea has the structure shown in Formula I:

[0039] In Formula I, the range of n is 2-7; R is an alkyl group; the number of carbon atoms in the alkyl group is 1-12, preferably 2-10.

[0040] In the present invention, the N-alkyl-N'-(hydroxyalkyl)-urea may specifically be:

[0041]

[0042] In the present invention, the preparation method of the N-alkyl-N'-(hydroxyalkyl)-urea preferably includes:

[0043] Adding a first amino alcohol compound and isocyanate in a molar ratio of 1:1 to ethyl acetate, heating under reflux for 30 min, cooling and then filtering to obtain a crude product, and recrystallizing the crude product with ethyl acetate to obtain N-alkyl-N'-(hydroxyalkyl)-urea.

[0044] In the present invention, the structural formula of the first amino alcohol compound is RNH(CH2)nOH, and the value of n in RNH(CH2)nOH is preferably the same as that in Formula I, which will not be elaborated here.

[0045] In the present invention, the alkyl carbamate alkyl urea has the structure shown in Formula II:

[0046] In Formula II, the range of n is 2 to 7;

[0047] R1 is an alkyl group; the number of carbon atoms of the alkyl group is 1 to 12, preferably 2 to 10.

[0048] In the present invention, the alkyl carbamate alkyl urea may specifically be:

[0049]

[0050] In the present invention, the mass of the gelator is preferably 0.5 to 10% of the total mass of the water, hydrocarbon fuel and nonionic surfactant, and more preferably 1 to 5%.

[0051] In the present invention, the second amino alcohol compound and isocyanate are added to ethyl acetate in a molar ratio of 1:2, heated under reflux for 30 min, cooled, and then filtered to obtain a crude product. The crude product is recrystallized with ethyl acetate to obtain the alkyl carbamate alkyl urea.

[0052] In the present invention, the structural formula of the second amino alcohol compound is R1NH(CH2)nOH, and the value of n in R1NH(CH2)nOH is preferably the same as that in Formula II, which will not be elaborated here.

[0053] In the present invention, the mass ratio of the water to the hydrocarbon fuel is preferably 5 to 50:50 to 95, and more preferably 5 to 20:80 to 95. In the present invention, the mass ratio of the nonionic surfactant is preferably 0.02 to 4% of the mass of the water, and more preferably 1:0.05 to 0.2. In the present invention, the mass of the gelator is preferably 0.5 to 10% of the total mass of the water, hydrocarbon fuel and nonionic surfactant, and more preferably 1 to 8%.

[0054] The present invention also provides a method for preparing a water / hydrocarbon fuel emulsion gel, comprising the following steps: after mixing water, hydrocarbon fuel, nonionic surfactant and gelator, heating to obtain the water / hydrocarbon fuel emulsion gel.

[0055] In the present invention, the mixing is preferably first mixing water, hydrocarbon fuel and nonionic surfactant, and then second mixing the obtained emulsion with the gelator.

[0056] In the present invention, the preferred manner of the first mixing is high-speed shearing. In the present invention, the frequency of the high-speed shearing is preferably 10,000 - 20,000 Hz, more preferably 15,000 Hz; the time is preferably 5 - 15 min, more preferably 10 min.

[0057] In the present invention, the temperature of the heating is preferably 75 - 85 °C, more preferably 80 °C; the time is preferably 10 - 20 min, more preferably 15 min.

[0058] In the present invention, after the heating, it is preferably further included to cool the product obtained by heating. In the present invention, no specific limitation is made to the cooling, and it can be cooled to room temperature.

[0059] To further illustrate the present invention, the following combines examples to describe the solution of the present invention in detail, but they cannot be understood as limiting the protection scope of the present invention.

[0060] Example 1

[0061] 5.0 g of water, 95.0 g of JP-10, 0.05 g of Span 80, and 0.95 g of Tween 80 were added to a flask, and high-speed shearing was carried out at 15,000 Hz for 10 min. After forming an emulsion, 2.0 g of N-isopropyl-N'-(hydroxyoctyl)-urea was added, heated to 80 °C, kept warm for 15 min, and left to stand and cool to room temperature to obtain the water / hydrocarbon fuel emulsion gel.

[0062] Example 2

[0063] 10.0 g of water, 95.0 g of JP-10, 0.1 g of Span 80, and 0.9 g of Tween 80 were added to a flask, and high-speed shearing was carried out at 15,000 Hz for 10 min. After forming an emulsion, 2.0 g of N-isopropyl-N'-(hydroxyoctyl)-urea was added, heated to 80 °C, kept warm for 15 min, and left to stand and cool to room temperature to obtain the water / hydrocarbon fuel emulsion gel.

[0064] Example 3

[0065] 15.0 g of water, 85.0 g of JP-10, 0.15 g of Span 80, and 0.85 g of Tween 80 were added to a flask, and high-speed shearing was carried out at 15,000 Hz for 10 min. After forming an emulsion, 2.0 g of N-isopropyl-N'-(hydroxyoctyl)-urea was added, heated to 80 °C, kept warm for 15 min, and left to stand and cool to room temperature to obtain the water / hydrocarbon fuel emulsion gel.

[0066] Example 4

[0067] Add 20.0 g of water, 80.0 g of JP-10, 0.2 g of Span 80, and 0.8 g of Tween 80 into a flask, and perform high-speed shearing at 15000 Hz for 10 min. After forming an emulsion, add 2.0 g of N-isopropyl-N'-(hydroxyoctyl)-urea, heat to 80 °C, keep warm for 15 min, and let it stand and cool to room temperature to obtain the water / hydrocarbon fuel emulsion gel.

[0068] Comparative Example 1

[0069] Add 10.0 g of water, 95.0 g of JP-10, 0.1 g of Span 80, and 0.9 g of Tween 80 into a flask, and perform high-speed shearing at 15000 Hz for 10 min to form an emulsion.

[0070] Test:

[0071] The present invention conducts rheological tests on the products prepared in Examples 1 to 4. The test conditions are as follows: at a frequency of 10 rad / s, continuously scan the water / hydrocarbon fuel emulsion gel samples at strains of 0.1% and 10% respectively, with each step lasting 60 s. The test results are shown in Figures 1 to 4 , and it can be seen from Figures 1 to 4 that when the gel is at a strain of 0.1%, it shows a gel state, and the storage modulus is greater than the loss modulus; when switched to a strain of 10%, both moduli decrease significantly, and the storage modulus is less than the loss modulus, and the gel shows a liquid state; after switching back to a low strain, both moduli increase significantly again, and the storage modulus is higher than the loss modulus again, and the gel quickly returns to the gel state.

[0072] The present invention conducts tests on the products prepared in Example 2 and Comparative Example 1 under simulated high centrifugal force conditions. The test method is to take 8 mL of the product and place it in a graduated centrifuge tube, and conduct tests at a rotation speed of 1000 - 5000 r / min, with a test rotation speed interval of 500 r / min, and observe the percentage of the damaged part of the product in the total volume. The test results are shown in Figure 5 , and it can be seen from Figure 5 that the water / hydrocarbon fuel emulsion gel prepared in Example 2 can slow down the damage to the emulsion system under high centrifugal force conditions.

[0073] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all embodiments. Other embodiments can be obtained based on these embodiments without creative work, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A water / hydrocarbon fuel emulsion gel, characterized in that, It includes water, hydrocarbon fuel, non-ionic surfactant and gel factor; The gel factor is selected from N-alkyl-N'-(hydroxyalkyl)-urea and / or alkyl urethane; The N-alkyl-N'-(hydroxyalkyl)-urea has the structure shown in Formula I: Formula I; in the said Formula I, the range of n is 2 to 7; The alkyl urethane has the structure shown in Formula II: Formula II; in the formula II, n ranges from 2 to 7; The R and R1 are independently alkyl; the number of carbon atoms of the alkyl is 1-12; The hydrocarbon fuel includes one or more of norbornane, alkanes with ≥8 carbon atoms and naphthalene compounds; The naphthalene compounds include one or more of tetralin, decalin, alkyl-substituted tetralin and alkyl-substituted decalin; The mass ratio of water to hydrocarbon fuel is 5-50:50-95; the mass of the gel factor is 0.5-10% of the total mass of water, hydrocarbon fuel and non-ionic surfactant.

2. The water / hydrocarbon fuel emulsion gel according to claim 1, characterized in that, The non-ionic surfactant includes Span 80 and Tween 80; Span 80 is 0.01-2% of the mass of water; Tween 80 is 0.01-2% of the mass of hydrocarbon fuel.

3. The preparation method of the water / hydrocarbon fuel emulsion gel according to any one of claims 1 to 2, characterized in that, It includes the following steps: After mixing water, hydrocarbon fuel, non-ionic surfactant and gel factor, heat it to obtain the water / hydrocarbon fuel emulsion gel.

4. The preparation method according to claim 3, wherein The mixing is to first mix water, hydrocarbon fuel and non-ionic surfactant to obtain an emulsion; The emulsion is secondarily mixed with the gel factor.

5. The preparation method according to claim 4, characterized in that, The way of the first mixing is high-speed shearing; the frequency of the high-speed shearing is 10000-20000 Hz and the time is 5-15 min.

6. The preparation method according to claim 3, characterized in that, The heating temperature is 75-85 °C and the time is 5-30 min.

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