High-stability methanol energized fuel and preparation method thereof

Abstract

The invention discloses a high-stability methanol energized fuel and a preparation method thereof.The high-stability methanol energized fuel is prepared from 70 to 75 parts of methanol, 3 to 5 parts of dimethyl carbonate, 3 to 4 parts of glycerol, 5 to 7 parts of high-carbon isoparaffin, 4 to 6 parts of bio-based high-carbon ester, 2 to 3 parts of bio-based emulsifier compound, 0.1 to 0.3 part of modified nano cerium oxide and 0.05 to 0.07 part of tri-tert-butyl phosphate; the corrosion inhibitor comprises the following components in parts by mass: 0.1 to 0.2 part of methyl tert-butyl ether and 0.03 to 0.05 part of benzotriazole. The high-stability methanol energized fuel disclosed by the invention has the stability and heat value of methanol fuel, and also has good temperature resistance; the preparation is simple, the operation is convenient, no additional heat source is needed, and the cost and energy consumption are reduced.

Description

Technical Field

[0001] This invention relates to a highly stable methanol-enhanced fuel and its preparation method, belonging to the field of methanol fuel technology. Background Technology

[0002] With the severe depletion of petroleum energy and the increasing awareness of environmental protection, finding alternative clean energy sources has become a hot topic. Methanol, with its small molecular weight, simple molecular structure, fast combustion speed, and strong anti-knock properties, is a promising alternative energy source.

[0003] Methanol fuel is typically prepared by first mixing methanol with additives to create a mixture, which is then used directly as fuel or blended with gasoline, diesel, or component oils in a specific ratio. It is a new type of clean fuel. Methanol fuel can replace gasoline and diesel in various motor vehicles, stoves, and other appliances. Developing methanol fuel to supplement and partially replace petroleum fuels can alleviate energy shortages, improve resource utilization, and protect the ecological environment.

[0004] Traditional industrial methanol fuels are mostly pure methanol, with a maximum calorific value of 4800 kcal / kg. When many users require higher calorific values ​​or combustion efficiency, existing fuels are insufficient. There are reports on improving calorific value, such as patent application number 201511013488.2, which discloses a methanol-coal-based blended fuel to improve the calorific value of methanol fuel. While this provides some improvement, it requires the use of medium- and low-temperature coal tar and both light and heavy coal tar. Patent application number 202310478859.2 discloses a modified methanol fuel for civilian use and its preparation method. By modifying methanol, it addresses the issue of low calorific value when using industrial methanol as fuel to some extent, but the improvement is limited. This application provides a highly stable methanol-enhanced fuel and its preparation method, balancing the stability and calorific value of methanol fuel while also exhibiting good temperature resistance. Summary of the Invention

[0005] This invention provides a highly stable methanol-enhanced fuel and its preparation method, which improves the stability and calorific value of methanol fuel, and has good temperature resistance and strong adaptability.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A highly stable methanol-enhanced fuel comprises: 70-75 parts methanol, 3-5 parts dimethyl carbonate, 3-4 parts glycerol, 5-7 parts high-carbon isoalkanes, 4-6 parts bio-based high-carbon esters, 2-3 parts bio-based emulsifier compound, 0.1-0.3 parts modified nano-cerium oxide, 0.05-0.07 parts tri-tert-butyl phosphate, 0.1-0.2 parts methyl tert-butyl ether, and 0.03-0.05 parts benzotriazole, wherein the parts are by weight.

[0008] Methanol is used as the base fuel. Dimethyl carbonate, as a co-solvent, increases the octane number and aids combustion. By carefully selecting its dosage, it avoids the calorific value dilution problem caused by excessive addition in existing solutions, and exhibits a significant synergistic effect with bio-based esters. Glycerol, as an antifreeze, has virtually no impact on the calorific value. High-carbon isoalkanes, as the core energy-enhancing component, increase the fuel's calorific value, exhibiting greater stability, higher calorific value, and better low-temperature fluidity compared to conventional heptane and petroleum ether. Bio-based high-carbon esters are used to assist in energy enhancement, improving the miscibility of methanol and hydrocarbons. Their bio-based origin is environmentally friendly, unlike conventional fatty acid methyl esters in existing patents, and they possess both energy-enhancing and solubilizing effects. Bio-based emulsifiers promote uniform dispersion of components, prevent stratification, and replace traditional chemical emulsifiers such as Span 80 and OP-7, improving environmental friendliness. Modified nano-cerium oxide can synergistically work with bio-based emulsifiers to improve storage stability and catalyze complete combustion. Tri-tert-butyl phosphate acts as an anti-wear agent, protecting engine seals and forming a synergistic corrosion protection effect with benzotriazole, thus improving fuel adaptability to equipment. Methyl tert-butyl ether enhances combustion and improves combustion efficiency; low-proportion addition achieves highly efficient combustion. Benzotriazole, as a corrosion inhibitor, solves the methanol corrosion problem by inhibiting methanol's corrosion of metal parts, thus addressing methanol fuel corrosion issues. Furthermore, the inventors discovered in experiments that the specific selection of modified nano-cerium oxide, high-carbon isoalkanes, bio-based high-carbon esters, and bio-based emulsifier complexes also produced a significant positive synergistic promoting effect with other components. While maintaining stability and calorific value, it also improves temperature resistance and fuel adaptability.

[0009] The methanol purity of this application is ≥99.5%.

[0010] To further improve the calorific value and stability of methanol fuel, as well as its temperature resistance, high-carbon isoalkanes have a carbon number of C12-C16.

[0011] To further enhance the positive synergistic effect with other materials, the high-carbon isoalkanes are composed of isododecane, isotetradecane, and isohexadecane, with a mass ratio of (45-55):(30-40):(10-20) for isododecane, isotetradecane, and isohexadecane. This compound ensures calorific value, solves the low-temperature flowability problem of C16, and improves miscibility with methanol, methyl ricinoleate, etc.

[0012] To further enhance energy efficiency while maintaining stability, the bio-based high carbon ester is methyl ricinoleate.

[0013] To further improve the stability of methanol fuel and its synergistic effect with other components, the bio-based emulsifier is a mixture of sucrose fatty acid ester and polyglycerol fatty acid ester in a 1:1 mass ratio. The inventors found in experiments that mixing them in the aforementioned ratio significantly improved the stability.

[0014] Further preferred, the polyglycerol fatty acid ester is polyglycerol stearate.

[0015] The modified cerium oxide nanoparticles described above have a particle size of 50-100 nm and are coated with polyethylene glycol. This surface modification solves the problem of nanoparticle agglomeration, distinguishing it from unmodified nanomaterials in existing patents, and also provides both stabilizing and combustion-supporting functions.

[0016] The preparation method of the above-mentioned modified nano-cerium oxide is as follows:

[0017] 1) Mix cerium nitrate, citric acid, PEG-4000, and water, and stir at room temperature for 30-40 minutes to obtain a transparent sol. The cerium nitrate content is 0.15-0.25 mol / L, the citric acid content is 0.08-0.12 mol / L, and the PEG-4000 content is 8-12 wt%.

[0018] 2) Heat and stir the sol obtained in step 1) at 50~60℃ in a water bath for 3~4h to form a uniform gel, then dry it at 90~100℃ for 8~12h, and then calcine it at 400~450℃ for 2.5~3h at a rate of 5~6℃ / min.

[0019] 3) Add the material obtained in step 2) to a 5-8 wt% PEG-6000 ethanol solution, disperse by ultrasonication, reflux for 2 hours, cool and centrifuge to dry, and obtain modified nano-cerium oxide with a particle size of 50-100 nm.

[0020] The preparation method of the above-mentioned highly stable methanol-enhanced fuel includes the following steps:

[0021] 1) Add plastic pellets to the reactor at 10-30% of the total methanol volume, then add 90-95% methanol, stir until the temperature rises to 40-45℃, add bio-based emulsifier compound, control the temperature at 40-45℃, stir for 20-30 minutes, then add glycerol, benzotriazole, dimethyl carbonate, tri-tert-butyl phosphate and methyl tert-butyl ether and stir for 5-10 minutes, then add dropwise a mixture of high carbon isoparaffins and bio-based high carbon esters. After the dropwise addition is complete, control the temperature at 40-45℃ and stir for 30-40 minutes.

[0022] 2) Add the modified nano-cerium oxide to the remaining methanol and ultrasonically disperse for 20-30 minutes (power 300W) to obtain a dispersion. This step solves the problem of nanoparticle aggregation and ensures stable performance.

[0023] 3) Under the stirring condition of controlling the temperature at 40~45℃, the dispersion obtained in step 2) is added dropwise to the material obtained in step 1). After the addition is completed, the temperature is controlled at 40~45℃ and stirred for 30~40 minutes. Then, the stirring is stopped, and the mixture is allowed to cool naturally to room temperature. The plastic pellets are filtered out and the mixture is allowed to stand for 8~12 hours to obtain highly stable methanol-enhanced fuel.

[0024] The above method utilizes the heat generated by stirring the plastic rice as the heat of reaction, eliminating the need for additional heating equipment and thus saving energy and being environmentally friendly. Furthermore, the temperature can be adjusted via the stirring speed, making it simple, convenient, and controllable. Generally, 0-1500 rpm is sufficient for the reaction. The required temperature is controlled by the stirring speed; when the temperature exceeds the required level, the speed needs to be reduced, and when the temperature falls below the required level, the speed needs to be increased to ensure the temperature remains within the desired range. In production, this can be achieved through a combined temperature and stirring speed control. This application does not offer any significant improvements to the specific control methods, and therefore will not be elaborated upon further.

[0025] The applicant has completed pilot testing. The method is feasible, environmentally friendly, low-cost, and the plastic rice can be reused.

[0026] In step 1) above, the plastic pellets are PP (polypropylene) or PE (polyethylene) with a particle size of 2-5mm.

[0027] Any techniques not mentioned in this invention are based on existing technologies.

[0028] This invention provides a highly stable methanol-enhanced fuel that balances the stability and calorific value of methanol fuel while also exhibiting good temperature resistance. It is simple to prepare, easy to operate, and requires no additional heat source, thus reducing costs and energy consumption. Detailed Implementation

[0029] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0030] Unless otherwise specified, all cases were conducted at room temperature (20~25℃).

[0031] Example 1

[0032] Preparation of modified nano-cerium oxide:

[0033] 1) Mix 86.85g cerium nitrate, 19.21g citric acid, 100g PEG-4000 and 1L water, and stir at room temperature for 35 minutes to obtain a transparent sol;

[0034] 2) Heat and stir the sol obtained in step 1) at 55°C in a water bath for 3.5 hours to form a uniform gel, then dry it at 100°C for 8-12 hours, and then calcine it at 425°C for 2.5 hours at a rate of 5°C / min.

[0035] 3) Add the material obtained in step 2) to a 6wt% PEG-6000 ethanol solution, disperse by ultrasonication, reflux for 2 hours, cool to room temperature, centrifuge at 4000 r / min for 10 min, collect the solid, and dry at 60℃ to constant weight to obtain modified nano-cerium oxide with an average particle size of 62 nm.

[0036] Example 2

[0037] A highly stable methanol-enhanced fuel is composed of the following components: 72 parts methanol (purity ≥ 99.5%), 4 parts dimethyl carbonate, 3 parts glycerol, 6 parts high-carbon isoalkanes, 5 parts bio-based high-carbon esters, 2 parts bio-based emulsifier compound, 0.12 parts modified nano-cerium oxide (prepared according to Example 1), 0.06 parts tri-tert-butyl phosphate, 0.1-0.2 parts methyl tert-butyl ether, and 0.03-0.05 parts benzotriazole, wherein the parts are by weight.

[0038] In this example, the high-carbon isoalkanes are a mixture of isododecane (Shellsol TD), isotetradecane (ExxonMobil Isopar M), and isohexadecane (Kao Corporation, Japan) in a mass ratio of 3:2:1. The bio-based high-carbon ester is methyl ricinoleate. The bio-based emulsifier compound is a mixture of sucrose fatty acid ester (Guangzhou Jiadel, SE-15) and hexaglycerol stearate (degree of polymerization n = 6, Shandong Binzhou Jinsheng New Material Technology Co., Ltd.) in a mass ratio of 1:1.

[0039] Methods for preparing highly stable methanol-enhanced fuels include:

[0040] 1) Add plastic rice (PP particles with a particle size of 3mm) to the reactor at 20% of the total methanol volume, then add 90% methanol, stir until the temperature rises to 40~45℃, add bio-based emulsifier compound, control the temperature at 40~45℃, stir for 30 minutes, then add glycerol, benzotriazole, dimethyl carbonate, tri-tert-butyl phosphate and methyl tert-butyl ether and stir for 10 minutes, then add dropwise (60 drops / min) a mixture of high carbon isoparaffin and bio-based high carbon ester. After the dropwise addition is complete, control the temperature at 40~45℃ and stir for 30 minutes.

[0041] 2) Add the modified nano-cerium oxide to the remaining methanol and ultrasonically disperse for 25 minutes (power 300W) to obtain a dispersion. This step solves the problem of nanoparticle aggregation and ensures stable performance.

[0042] 3) Under stirring conditions with a controlled temperature of 40~45℃, the dispersion obtained in step 2) is added dropwise (60 drops / min) to the material obtained in step 1). After the addition is complete, the temperature is controlled at 40~45℃ and stirred for 30 min. Then, stirring is stopped, and the mixture is allowed to cool naturally to room temperature. The plastic pellets are filtered out, and the mixture is allowed to stand for 8 h to obtain a highly stable methanol-enhanced fuel with a calorific value of 11623 Kcal / Kg. After standing at room temperature for 24 months, no stratification is observed; after standing at -20℃ for 24 months, no stratification is observed; after standing at 40℃ for 24 months, no stratification is observed.

[0043] Comparative Example 1

[0044] The difference from Example 2 is that the modified nano-cerium oxide was replaced with commercially available cerium oxide, while the rest was the same as in Example 2, resulting in particle agglomeration. The calorific value was 10238 Kcal / Kg; after standing at -20℃ for 16 months, stratification occurred; after standing at 40℃ for 11 months, stratification also occurred.

[0045] Comparative Example 2

[0046] The difference from Example 2 is that the modified nano-cerium oxide was omitted, while the rest was the same as in Example 2. The calorific value was 9583 kcal / kg; after standing at -20°C for 12 months, stratification occurred; after standing at 40°C for 8 months, stratification also occurred.

[0047] Comparative Example 3

[0048] The difference from Example 2 is that the bio-based high carbon ester was replaced with methyl oleate, while the rest were the same as in Example 2. The calorific value was 10048 kcal / kg. After standing at -20°C for 8 months, stratification occurred; after standing at 40°C for 6 months, stratification occurred.

[0049] Comparative Example 4

[0050] The difference from Example 2 is that the bio-based high carbon ester was replaced with methyl stearate, and all other aspects were the same as in Example 2. The calorific value was 10109 Kcal / Kg. After standing at -20°C for 9 months, stratification occurred; after standing at 40°C for 8 months, stratification occurred.

[0051] Comparative Example 5

[0052] The difference from Example 2 is that the bio-based high carbon ester was replaced with methyl lauryl ester, while the rest were the same as in Example 2. The calorific value was 10236 kcal / kg. After standing at -20°C for 15 months, stratification occurred; after standing at 40°C for 13 months, stratification also occurred.

[0053] Comparative Example 6

[0054] The difference from Example 2 is that the bio-based high carbon ester was replaced with methyl phosphate, and the rest were the same as in Example 2. The calorific value was 9921 kcal / kg. After standing at -20°C for 7 months, stratification occurred; after standing at 40°C for 6 months, stratification occurred.

[0055] Comparative Example 6

[0056] The difference from Example 2 is that the bio-based high carbon ester was omitted, and the rest were the same as in Example 2. The calorific value was 9036 Kcal / Kg. After standing at -20°C for 5 months, stratification occurred; after standing at 40°C for 4 months, stratification occurred.

[0057] Comparative Example 7

[0058] The difference from Example 2 is that the high-carbon isoalkanes are isododecane, and the rest are the same as in Example 2. The calorific value is 9948 Kcal / Kg. After standing at -20°C for 14 months, stratification occurs; after standing at 40°C for 8 months, stratification occurs.

[0059] Comparative Example 8

[0060] The difference from Example 2 is that the high-carbon isoalkanes are isotetradecane, and the rest are the same as in Example 2. The calorific value is 10021 Kcal / Kg. After standing at -20°C for 14 months, stratification occurs; after standing at 40°C for 8 months, stratification occurs.

[0061] Comparative Example 9

[0062] The difference from Example 2 is that the high-carbon isoalkanes are hexadecane isoforms, and the rest are the same as in Example 2. The calorific value is 10054 Kcal / Kg. After standing at -20°C for 15 months, stratification occurs; after standing at 40°C for 10 months, stratification occurs.

[0063] Comparative Example 10

[0064] The difference from Example 2 is that the high-carbon isoalkanes are a mixture of isododecane and isotetradecane in a mass ratio of 3:2, and the rest are the same as in Example 2. The calorific value is 10724 Kcal / Kg. After standing at -20°C for 16 months, stratification occurs; after standing at 40°C for 12 months, stratification occurs.

[0065] Comparative Example 11

[0066] The difference from Example 2 is that the high-carbon isoalkanes are a mixture of isododecane and isohexadecane in a mass ratio of 3:1, and the rest are the same as in Example 2. The calorific value is 10836 Kcal / Kg. After standing at -20°C for 16 months, stratification occurs; after standing at 40°C for 13 months, stratification occurs.

[0067] Comparative Example 12

[0068] The difference from Example 2 is that the high-carbon isoalkanes are a mixture of isotetradecane and isohexadecane in a mass ratio of 2:1, while the rest are the same as in Example 2. The calorific value is 10919 Kcal / Kg, and the mixture separates into layers after standing at 40°C for 15 months.

[0069] Comparative Example 13

[0070] The difference from Example 2 is that the high-carbon isoalkanes were replaced with heptane, and all other aspects were the same as in Example 2. The calorific value was 9910 Kcal / Kg. After standing at -20°C for 3 months, stratification occurred; after standing at 40°C for 6 months, stratification occurred.

[0071] Comparative Example 14

[0072] The difference from Example 2 is that the high-carbon isoalkanes were replaced with petroleum ether, while the rest were the same as in Example 2. The calorific value was 9823 kcal / kg. After standing at -20°C for 5 months, stratification occurred; after standing at 40°C for 6 months, stratification occurred.

[0073] Comparative Example 15

[0074] The difference from Example 2 is that the bio-based emulsifier compound was replaced with sucrose fatty acid ester, while the rest were the same as in Example 2. The calorific value was 11109 Kcal / Kg. After standing at -20°C for 15 months, stratification occurred; after standing at 40°C for 12 months, stratification also occurred.

[0075] Comparative Example 16

[0076] The difference from Example 2 is that the bio-based emulsifier compound was replaced with hexaglycerol stearate, while the rest were the same as in Example 2. The calorific value was 11132 kcal / kg. After standing at -20°C for 15 months, stratification occurred; after standing at 40°C for 13 months, stratification also occurred.

[0077] Comparative Example 17

[0078] The difference from Example 2 is that the bio-based emulsifier compound was replaced with Span 80, while the rest were the same as in Example 2. The calorific value was 10929 Kcal / Kg. After standing at room temperature for 16 months, the mixture separated into layers. After standing at -20°C for 8 months, the mixture separated into layers. After standing at 40°C for 8 months, the mixture separated into layers.

[0079] Comparative Example 18

[0080] The difference from Example 2 is that the bio-based emulsifier compound was replaced with OP-7, while the rest were the same as in Example 2. The calorific value was 10987 Kcal / Kg. After standing at room temperature for 15 months, the mixture separated into layers. After standing at -20°C for 7 months, the mixture separated into layers. After standing at 40°C for 9 months, the mixture separated into layers.

[0081] Comparative Example 19

[0082] The difference from Example 2 is that the bio-based emulsifier compound was replaced with a mixture of Span 80 and OP-7 in a mass ratio of 1:1. All other aspects were the same as in Example 2. The calorific value was 11002 Kcal / Kg. After standing at room temperature for 20 months, the mixture separated into layers. After standing at -20°C for 8 months, the mixture separated into layers. After standing at 40°C for 9 months, the mixture separated into layers.

Claims

1. A highly stable methanol-enhanced fuel, characterized in that: include: The ingredients are: 70-75 parts methanol, 3-5 parts dimethyl carbonate, 3-4 parts glycerol, 5-7 parts high-carbon isoalkanes, 4-6 parts bio-based high-carbon esters, 2-3 parts bio-based emulsifier compound, 0.1-0.3 parts modified nano-cerium oxide, 0.05-0.07 parts tri-tert-butyl phosphate, 0.1-0.2 parts methyl tert-butyl ether, and 0.03-0.05 parts benzotriazole. All parts are by weight.

2. The highly stable methanol-enhanced fuel according to claim 1, characterized in that: High-carbon isoalkanes have 12-16 carbon atoms.

3. The highly stable methanol-enhanced fuel according to claim 1 or 2, characterized in that: The high-carbon isoalkanes are composed of isododecane, isotetradecane and isohexadecane, wherein the mass ratio of isododecane, isotetradecane and isohexadecane is (45-55): (30-40): (10-20).

4. The highly stable methanol-enhanced fuel according to claim 1 or 2, characterized in that: The bio-based high carbon ester is methyl ricinoleate.

5. The highly stable methanol-enhanced fuel according to claim 1 or 2, characterized in that: The bio-based emulsifier is a mixture of sucrose fatty acid ester and polyglycerol fatty acid ester in a 1:1 mass ratio.

6. The highly stable methanol-enhanced fuel according to claim 6, characterized in that: The polyglycerol fatty acid ester is polyglycerol stearate.

7. The highly stable methanol-enhanced fuel according to claim 1 or 2, characterized in that: The modified nano-cerium oxide has a particle size of 50-100 nm and is coated with polyethylene glycol.

8. The highly stable methanol-enhanced fuel according to claim 1 or 2, characterized in that: The preparation method of modified nano-cerium oxide is as follows: 1) Mix cerium nitrate, citric acid, PEG-4000, and water, and stir at room temperature for 30-40 minutes to obtain a transparent sol. The cerium nitrate content is 0.15-0.25 mol / L, the citric acid content is 0.08-0.12 mol / L, and the PEG-4000 content is 8-12 wt%. 2) Heat and stir the sol obtained in step 1) at 50~60℃ in a water bath for 3~4h to form a uniform gel, then dry it at 90~100℃ for 8~12h, and then calcine it at 400~450℃ for 2.5~3h at a rate of 5~6℃ / min. 3) Add the material obtained in step 2) to a 5-8 wt% PEG-6000 ethanol solution, disperse by ultrasonication, reflux for 2 hours, cool and centrifuge to dry, and obtain modified nano-cerium oxide with a particle size of 50-100 nm.

9. A method for preparing a highly stable methanol-enhanced fuel, characterized in that: Includes the following steps: 1) Add plastic pellets to the reactor at 10-30% of the total methanol volume, then add 90-95% methanol, stir until the temperature rises to 40-45℃, add bio-based emulsifier compound, control the temperature at 40-45℃, stir for 20-30 minutes, then add glycerol, benzotriazole, dimethyl carbonate, tri-tert-butyl phosphate and methyl tert-butyl ether and stir for 5-10 minutes, then add dropwise a mixture of high carbon isoparaffins and bio-based high carbon esters. After the dropwise addition is complete, control the temperature at 40-45℃ and stir for 30-40 minutes. 2) Add the modified nano-cerium oxide to the remaining methanol and ultrasonically disperse for 20-30 minutes to obtain a dispersion; 3) Under the stirring condition of controlling the temperature at 40~45℃, the dispersion obtained in step 2) is added dropwise to the material obtained in step 1). After the addition is completed, the temperature is controlled at 40~45℃ and stirred for 30~40 minutes. Then, the stirring is stopped, and the mixture is allowed to cool naturally to room temperature. The plastic pellets are filtered out and the mixture is allowed to stand for 8~12 hours to obtain highly stable methanol-enhanced fuel.

10. The method for preparing highly stable methanol-enhanced fuel according to claim 9, characterized in that: In step 1), the plastic pellets are PP or PE with a particle size of 2-5mm.