Methanol fuel and method for its preparation

Abstract

The application provides a kind of methanol fuel and its preparation method, it relates to fuel technical field.Methanol fuel, including 95%-99% methanol and 1%-5% additive, the additive is 1-butyl-3-methyl imidazole tetrafluoroborate, straight chain alkyl acid, polystyrene-polyether type amphiphilic block copolymer, ethylene glycol monobutyl ether and N,N-dihydroxyethyl-p-toluidine.The additive of the application and methanol have good compatibility, under the premise of not affecting the quality of methanol fuel, the octane number of methanol fuel is increased by 4-6 units, the combustion performance and lubricating property of methanol fuel are improved, the low temperature fluidity of methanol fuel is improved, the corrosion of external factors metal is effectively blocked, and the application prospect is good.

Description

Technical Field

[0001] This invention relates to the field of fuel technology, and in particular to a methanol fuel and its preparation method. Background Technology

[0002] Methanol, as a clean alternative fuel, has advantages such as wide availability, high oxygen content, and clean combustion emissions. Its octane number is higher than that of ordinary gasoline. The high octane number of methanol indicates that it has better anti-knock properties and can burn at a higher compression ratio without knocking. However, methanol has a low calorific value, which means that methanol provides less energy in the same volume. Therefore, when using methanol as fuel, more fuel may be needed to provide the same energy output, which may affect the driving range of the car. In addition, methanol fuel also has the following technical defects in practical applications: (1) Strong corrosiveness: Methanol is highly polar and easily absorbs water. During production and storage, trace amounts of formic acid may be formed, which will corrode metal parts; (2) Poor lubricity: Methanol has low viscosity and its lubricity is much worse than that of gasoline and diesel. It cannot form an effective lubricating oil film on the friction pair surface, which leads to abnormal wear of components such as high-pressure oil pumps and plungers; (3) Carbon deposits: Incomplete combustion of methanol or the presence of impurities can easily form deposits in the injectors and combustion chamber; (4) It becomes turbid and separates when exposed to water and is unstable under low temperature conditions. Summary of the Invention

[0003] Therefore, this invention proposes a methanol fuel and a method for its preparation.

[0004] The technical solution of this invention is implemented as follows: A methanol fuel comprising 95%-99% methanol and 1%-5% additives; The additives are 1-butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid, polystyrene-polyether type amphiphilic block copolymer, ethylene glycol monobutyl ether, and N,N-dihydroxyethyl-p-toluidine.

[0005] 1-Butyl-3-methylimidazolium tetrafluoroborate, [BMIM]BF4, is a room-temperature ionic liquid with the chemical formula C8H. 15 N2BF4, molecular weight 226.02.

[0006] Ethylene glycol monobutyl ether is an organic compound with the chemical formula C6H. 14 O2 is a colorless and transparent liquid that is soluble in water, acetone, benzene, ether, methanol, carbon tetrachloride and other organic solvents and mineral oils. It is mainly used as a high-boiling-point solvent for paints, especially nitrocellulose lacquer, quick-drying varnish, varnish, enamel and paint remover. It is also used as a non-reactive diluent for adhesives, metal detergent, paint remover, fiber wetting agent, pesticide dispersant, drug extractant and resin plasticizer.

[0007] N,N-Dihydroxyethyl-p-toluidine, with the molecular formula C0 11 H 17 NO2 contains two hydroxyethyl substituents, giving it both hydrophilicity and reactivity.

[0008] Furthermore, the additive, by weight, comprises 3-5 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-4 parts of linear alkyl acid, 0.5-1.5 parts of polystyrene-polyether amphiphilic block copolymer, 5-10 parts of ethylene glycol monobutyl ether and 3-5 parts of N,N-dihydroxyethyl-p-toluidine.

[0009] Furthermore, the additive, by weight, comprises 4 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 3 parts of linear alkyl acid, 1 part of polystyrene-polyether amphiphilic block copolymer, 8 parts of ethylene glycol monobutyl ether, and 4 parts of N,N-dihydroxyethyl-p-toluidine.

[0010] Furthermore, the straight-chain alkyl acid is octanoic acid, arachidic acid, and palmitic acid in a mass ratio of 1:0.6-0.8:0.3-0.5.

[0011] Furthermore, the straight-chain alkyl acid is octanoic acid, arachidic acid, and palmitic acid in a mass ratio of 1:0.7:0.4.

[0012] Octanoic acid, an organic compound with the molecular formula C8H. 16 O2 is used in the manufacture of dyes, pharmaceuticals, and fragrances. It is also used as a plasticizer, lubricant, insecticide, mildew inhibitor, rust inhibitor, corrosion inhibitor, foaming agent, and defoamer. It is also used in ore separation.

[0013] Arachidonic acid is a saturated fatty acid with CAS number 506-30-9. Its molecular formula is C2. 20 H 40 O2, molecular weight 312.53.

[0014] Palmitic acid is a saturated fatty acid organic compound with the chemical formula C. 16 H 32 O2, with a relative molecular weight of 256.42, is the sodium salt of palmitic acid, a major component of soap. It can also be used to manufacture metal palmitic acid salts, lubricants, synthetic detergents, softeners, emulsifiers, flotation agents, waterproofing materials, and candles. In the pharmaceutical industry, it can be used to prepare odorless chlortetracycline and chloramphenicol.

[0015] Furthermore, the polystyrene-polyether amphiphilic block copolymer is polystyrene-b-polyoxyethylene glycidyl acrylate.

[0016] A method for preparing methanol fuel, wherein the additive is added to methanol.

[0017] Furthermore, the preparation steps of the additive are as follows: 1-Butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid and ethylene glycol monobutyl ether were mixed and stirred, and then polystyrene-polyether amphiphilic block copolymer and N,N-dihydroxyethyl-p-toluidine were added and stirred continuously to obtain the additive.

[0018] Furthermore, the mixing speed is 300-400 rpm, and the time is 40-60 min.

[0019] Furthermore, the stirring speed is 100-200 rpm and the stirring time is 20-30 min.

[0020] Compared with the prior art, the beneficial effects of the present invention are: The additive of this invention has good compatibility with methanol. Without affecting the quality of methanol fuel, it increases the octane number of methanol fuel by 4-6 units, improves the combustion and lubrication performance of methanol fuel, improves the low-temperature fluidity of methanol fuel, and effectively blocks corrosion of external metals.

[0021] The 1-butyl-3-methylimidazolium tetrafluoroborate of the present invention, when added to methanol fuel additives, promotes complete combustion and reduces carbon deposit formation by lowering the activation energy of methanol oxidation. At the same time, its ionic conductivity is used to promptly dissipate static charge, eliminating static safety hazards during fuel storage and transportation.

[0022] The imidazole cation of 1-butyl-3-methylimidazolium tetrafluoroborate forms an ion-dipole interaction with the polyoxyethylene segment in polystyrene-b-polyoxyethylene glycidyl acrylate, constructing a three-dimensional supramolecular network structure. This network, on the one hand, prevents water molecule-induced phase separation through a physical barrier, and on the other hand, utilizes the epoxy groups of glycidyl acrylate to chemically bond with the hydroxyl groups on the metal surface, forming a stable anti-corrosion interface layer.

[0023] 1-Butyl-3-methylimidazolium tetrafluoroborate forms an ionic layer on the metal surface through electrostatic adsorption, while the linear alkyl acid provides a lubricating oil film. Together, they achieve dual protection of "corrosion prevention and lubrication". At the same time, this ionic liquid and the linear alkyl acid work together to improve combustion efficiency during combustion.

[0024] 1-Butyl-3-methylimidazolium tetrafluoroborate can significantly reduce the interfacial tension between methanol and additives, while ethylene glycol monobutyl ether, as a small molecule co-solvent, further promotes the formation of homogeneous microemulsions. The two work synergistically to reduce the overall surface tension of the liquid and improve low-temperature fluidity.

[0025] 1-Butyl-3-methylimidazolium tetrafluoroborate and N,N-dihydroxyethyl p-toluidine undergo synergistic competitive adsorption on the metal surface. The imidazolium cation coordinates with the empty orbitals of the metal via π-electrons, while the hydroxyl and amino groups of N,N-dihydroxyethyl p-toluidine adsorb to adjacent sites via hydrogen bonds and coordination bonds. Together, they form a dense and ordered anti-corrosion passivation layer, effectively preventing corrosion of the metal.

[0026] The polyoxyethylene segments of the polystyrene-b-polyoxyethylene glycidyl acrylate of the present invention form a hydrogen bond network with the carboxyl groups of the straight-chain alkyl acid, which can induce the straight-chain alkyl acid to arrange in an orderly manner on the metal surface, significantly enhance the density and mechanical strength of the lubricating film, and reduce the coefficient of friction. The two work synergistically to significantly improve the lubrication performance of methanol fuel.

[0027] The ethylene glycol monobutyl ether of the present invention is embedded in the intersegment of polyoxyethylene segments of polystyrene-b-polyoxyethylene glycidyl acrylate, thereby increasing the segment flexibility and significantly improving the thermodynamic stability and water resistance of the microemulsion.

[0028] The N,N-dihydroxyethyl-p-toluidine of the present invention inhibits the oxidative degradation of straight-chain alkyl acids by capturing free radicals, thereby extending the effective life of the lubricating film. At the same time, the nonpolar long carbon chain of the straight-chain alkyl acid provides a stable hydrophobic microenvironment for N,N-dihydroxyethyl-p-toluidine, reducing its direct contact with water and maintaining its antioxidant activity. Detailed Implementation

[0029] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0030] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0031] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0032] The linear alkyl acids of the present invention are octanoic acid, arachidic acid and palmitic acid in a mass ratio of 1:0.7:0.4.

[0033] Example 1 A methanol fuel comprising 97% methanol and 3% additives; The additives, by weight, include 4 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 3 parts of linear alkyl acid, 1 part of polystyrene-b-polyoxyethylene glycidyl acrylate, 8 parts of ethylene glycol monobutyl ether and 4 parts of N,N-dihydroxyethyl-p-toluidine. The preparation steps of the above additive are as follows: 1-Butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid and ethylene glycol monobutyl ether are mixed and stirred at 350 rpm for 50 min, polystyrene-b-polyoxyethylene glycidyl acrylate and N,N-dihydroxyethyl p-toluidine are added and stirred at 150 rpm for 25 min to obtain the additive.

[0034] The preparation steps for methanol fuel are as follows: add the additive to methanol and mix evenly to obtain the product.

[0035] Example 2 A methanol fuel comprising 95% methanol and 5% additives; The additives, by weight, include 3 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 1 part linear alkyl acid, 0.5 parts polystyrene-b-polyoxyethylene glycidyl acrylate, 5 parts ethylene glycol monobutyl ether, and 3 parts N,N-dihydroxyethyl-p-toluidine.

[0036] The preparation steps of the above additive are as follows: 1-Butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid and ethylene glycol monobutyl ether are mixed and stirred at 300 rpm for 40 min, polystyrene-b-polyoxyethylene glycidyl acrylate and N,N-dihydroxyethyl p-toluidine are added and stirred at 100 rpm for 20 min to obtain the additive.

[0037] The preparation steps for methanol fuel are as follows: add the additive to methanol and mix evenly to obtain the product.

[0038] Example 3 A methanol fuel comprising 99% methanol and 1% additives; The additives, by weight, include 5 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts of linear alkyl acid, 1.5 parts of polystyrene-b-polyoxyethylene glycidyl acrylate, 10 parts of ethylene glycol monobutyl ether, and 5 parts of N,N-dihydroxyethyl-p-toluidine.

[0039] The preparation steps of the above additive are as follows: 1-Butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid and ethylene glycol monobutyl ether are mixed and stirred at 400 rpm for 60 min, polystyrene-b-polyoxyethylene glycidyl acrylate and N,N-dihydroxyethyl p-toluidine are added and stirred at 200 rpm for 30 min to obtain the additive.

[0040] The preparation steps for methanol fuel are as follows: add the additive to methanol and mix evenly to obtain the product.

[0041] Comparative Example 1 The difference from Example 1 is that 1-butyl-3-methylimidazolium tetrafluoroborate is missing from the additive. The missing substance is allocated according to the proportion of other substances in the additive. Otherwise, it is the same as Example 1.

[0042] Comparative Example 2 The difference from Example 1 is that the additive lacks straight-chain alkyl acids, and the missing substances are allocated according to the proportion of other substances in the additive; otherwise, it is the same as Example 1.

[0043] Comparative Example 3 The difference from Example 1 is that the additive lacks polystyrene-b-polyoxyethylene glycidyl acrylate. The missing substance is allocated according to the proportion of other substances in the additive, and otherwise it is the same as Example 1.

[0044] Comparative Example 4 The difference from Example 1 is that the additive lacks ethylene glycol monobutyl ether, and the missing substance is allocated according to the proportion of other substances in the additive; otherwise, it is the same as Example 1.

[0045] Comparative Example 5 The difference from Example 1 is that N,N-dihydroxyethyl p-toluidine is missing from the additive. The missing substance is allocated according to the proportion of other substances in the additive. Otherwise, it is the same as Example 1.

[0046] Test Example 1 The methanol fuels prepared in Examples 1-3 and Comparative Examples 1-5 were evaluated for performance. The specific test items were: octane number determination, low temperature fluidity, fuel stability and corrosivity.

[0047] 1. Octane number determination: The research octane number was determined using the ASTM D2699 standard method with a CFR engine. Ambient temperature: 25°C; relative humidity: 60%; atmospheric pressure: 101.3 kPa.

[0048] 2. Low-temperature fluidity: The pour point of the fuel was determined using the ASTM D97 standard method. A low-temperature constant-temperature bath was used, with a temperature range of -60℃ to 0℃ and a cooling rate of 3℃ / h.

[0049] 3. Fuel stability: The oxidation stability of the fuel was determined using the ASTM D525 standard method. The temperature was 100°C, the oxygen pressure was 700 kPa, and the test lasted until the pressure dropped.

[0050] 4. Corrosion: The copper sheet corrosion test was conducted using the ASTM D130 standard method. Temperature: 50℃; Time: 3 hours.

[0051] The results are shown in Table 1.

[0052] Table 1

[0053] As can be seen from Table 1, the methanol fuels of Examples 1-3 of the present invention have high octane numbers, excellent low-temperature fluidity and fuel stability, and excellent corrosion resistance.

[0054] Test Example 2 The methanol fuels prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests, including water solubility test, cold start performance test, and long-term storage stability test.

[0055] 1. Water solubility test: The phase separation of fuel with different water contents of 0.1%-2% was determined using the ASTM D1094 standard method within the temperature range of 0-40℃ (fuel sample was mixed with water and equilibrated in a constant temperature water bath for 2 hours).

[0056] 2. Cold start performance test: The engine start time and stability are tested at a temperature of -30℃.

[0057] 3. Long-term storage stability test: The fuel sample was sealed and stored at 40°C for 6 months, and the increase in acid value after 6 months was measured.

[0058] The results are shown in Table 2.

[0059] Table 2

[0060] As can be seen from Table 2, the methanol fuel prepared in Examples 1-3 of this invention has excellent water resistance and cold start performance, which improves the long-term storage stability of methanol fuel.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A methanol fuel, characterized in that, Includes 95%-99% methanol and 1%-5% additives; The additives are 1-butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid, polystyrene-polyether type amphiphilic block copolymer, ethylene glycol monobutyl ether, and N,N-dihydroxyethyl-p-toluidine.

2. The methanol fuel as described in claim 1, characterized in that, The additives, by weight, include 3-5 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-4 parts of linear alkyl acid, 0.5-1.5 parts of polystyrene-polyether amphiphilic block copolymer, 5-10 parts of ethylene glycol monobutyl ether, and 3-5 parts of N,N-dihydroxyethyl-p-toluidine.

3. A methanol fuel as described in claim 2, characterized in that, The additives, by weight, comprise 4 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 3 parts of linear alkyl acid, 1 part of polystyrene-polyether amphiphilic block copolymer, 8 parts of ethylene glycol monobutyl ether, and 4 parts of N,N-dihydroxyethyl-p-toluidine.

4. A methanol fuel as described in claim 1, characterized in that, The linear alkyl acid is octanoic acid, arachidic acid, and palmitic acid in a mass ratio of 1:0.6-0.8:0.3-0.

5.

5. A methanol fuel as described in claim 4, characterized in that, The linear alkyl acid is octanoic acid, arachidic acid, and palmitic acid in a mass ratio of 1:0.7:0.

4.

6. A methanol fuel as described in claim 1, characterized in that, The polystyrene-polyether amphiphilic block copolymer is polystyrene-b-polyoxyethylene glycidyl acrylate.

7. A method for preparing methanol fuel according to any one of claims 1-6, characterized in that, The preparation step involves adding the additive to methanol.

8. The method for preparing methanol fuel as described in claim 7, characterized in that, The preparation steps of the additive are as follows: 1-Butyl-3-methylimidazolium tetrafluoroborate, linear alkyl acid and ethylene glycol monobutyl ether were mixed and stirred, and then polystyrene-polyether amphiphilic block copolymer and N,N-dihydroxyethyl-p-toluidine were added and stirred continuously to obtain the additive.

9. The method for preparing methanol fuel as described in claim 8, characterized in that, The mixing speed is 300-400 rpm, and the time is 40-60 min.

10. The method for preparing methanol fuel as described in claim 8, characterized in that, The stirring speed is 100-200 rpm, and the time is 20-30 min.

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