Methanol fuel mother liquid additive and preparation method thereof

Abstract

The invention relates to the technical field of methanol fuel liquid additives, in particular to a methanol fuel mother liquid additive and a preparation method thereof, comprising the following components by weight: A. 35-45 parts of oxygen-containing synergist; B. 20-30 parts of combustion improver; C. 15-25 parts of free radical regulator; D. 10-20 parts of surfactant; E. 5-10 parts of corrosion inhibitor, which not only increases the octane number of methanol fuel to more than 105, but also improves the low-temperature fluidity to less than -50°C. More surprisingly, the invention significantly increases the combustion speed and comprehensively reduces harmful emissions.

Description

Technical Field

[0001] The invention relates to the technical field of methanol fuel liquid additives, in particular to a methanol fuel mother liquid additive and a preparation method thereof. Background Art

[0002] With the increasingly severe energy crisis and environmental problems, the development of clean and efficient alternative fuels has become a top priority. Methanol, as a widely available, clean and environmentally friendly liquid fuel, has shown great potential in the automotive field. However, methanol fuel also faces a series of technical challenges, such as insufficient octane number, poor low-temperature fluidity, and strong corrosiveness, which seriously restrict its large-scale application.

[0003] Methanol has a higher octane rating, which means it has better anti-knock properties and can burn at higher compression ratios without knocking. However, compared to conventional gasoline, methanol has a lower calorific value, which means it provides less energy for the same volume. Therefore, when using methanol as a fuel, more fuel may be required to provide the same energy output, which may affect the vehicle's range.

[0004] Methanol has poor low-temperature fluidity, which means that in cold environments, methanol fuel may become more viscous, affecting its fluidity and spray characteristics in the fuel system. This can lead to difficult starting and reduced engine performance in cold weather.

[0005] Methanol is highly corrosive, mainly to metal engine parts. During combustion, methanol may generate corrosive substances such as formic acid, which can damage engine pistons, cylinder walls and other parts. In addition, methanol is highly hygroscopic and absorbs moisture during storage and transportation, which increases its corrosiveness.

[0006] In the prior art, ether compounds or metal organics are usually added to increase the octane number of methanol fuel, but these methods often bring new environmental problems. On the other hand, in order to improve low-temperature performance, although commonly used alcohol or ether additives can reduce the freezing point to a certain extent, they cannot effectively solve the problem of low-temperature starting difficulties. In addition, the strong polarity of methanol makes it highly corrosive, and existing corrosion inhibitors are often difficult to disperse evenly in methanol, and the long-term use effect is poor. Summary of the invention

[0007] Aiming at the shortcomings of existing methanol gasoline additives, the present invention proposes a multifunctional and efficient methanol fuel mother liquid additive and a preparation method thereof. The additive achieves multiple technical breakthroughs through a carefully designed multi-component formula and an innovative preparation process.

[0008] The object of the present invention is to provide a methanol fuel mother liquid additive, which comprises the following components in parts by weight:

[0009] A. 35-45 parts of oxygen-containing synergist;

[0010] B. Combustion improver 20-30 parts;

[0011] C. 15-25 parts of free radical regulator;

[0012] D. 10-20 parts of surfactant;

[0013] E. Corrosion inhibitor 5-10 parts.

[0014] Preferably, the oxygen-containing synergist comprises:

[0015] 2-methoxyethanol 15-20 parts;

[0016] 10-15 parts of tetrahydrofuran;

[0017] 1,3-dioxolane 10-12 parts.

[0018] Preferably, the combustion improver comprises:

[0019] 10-15 parts of 2-ethylhexyl nitrate;

[0020] 5-8 parts of tetralin;

[0021] 5-7 parts of methyl tert-butyl ether.

[0022] Preferably, the free radical regulator comprises:

[0023] 7-10 parts of N,N′-di-sec-butyl-p-phenylenediamine;

[0024] 2,4,6-trimethylphenol 5-8 parts;

[0025] 3-7 parts of 4-methylpyridine.

[0026] Preferably, the surfactant comprises:

[0027] 5-8 parts of sorbitan monooleate;

[0028] 3-6 parts of sodium lauryl sulfate;

[0029] 2-6 parts of polyethylene glycol.

[0030] Preferably, the corrosion inhibitor comprises:

[0031] 2-Mercaptobenzothiazole 2-4 parts;

[0032] 2-3 parts of benzotriazole;

[0033] 1-3 parts of ethylenediaminetetraacetic acid.

[0034] A method for preparing the methanol fuel mother liquid additive comprises the following steps:

[0035] (1) preparing an oxygen-containing synergist;

[0036] (2) preparing combustion improver;

[0037] (3) preparing a free radical regulator;

[0038] (4) preparing a surfactant;

[0039] (5) Preparation of corrosion inhibitors;

[0040] (6) Mixing the products obtained in steps (1) to (5) to obtain the methanol fuel mother liquid additive.

[0041] Preferably, in step (1), first, at 40-50° C., 2-methoxyethanol is added to a three-necked flask equipped with a mechanical stirrer and a condensing reflux device, and stirring is started at a speed of 300 rpm; then, tetrahydrofuran and 1,3-dioxolane are slowly added in sequence; under nitrogen protection, the temperature is raised to 45° C. and the reaction is carried out for 1.5 hours.

[0042] Preferably, in step (2), tetralin is first added to a pressure-resistant reactor, the temperature is set to 25° C., stirring is started at a speed of 250 rpm; then isooctyl nitrate is slowly added; after stirring evenly, methyl tert-butyl ether is slowly added; the temperature is raised to 60° C., and the reaction is carried out for 2.5 hours under the protection of an inert gas.

[0043] Preferably, in step (6), firstly, add the oxygen-containing enhancer to a large reactor equipped with a high-speed disperser, start stirring at a speed of 450 rpm; then slowly add the combustion improver, free radical regulator, surfactant and corrosion inhibitor in sequence, stirring for 10 minutes after each component is added; finally, under nitrogen protection, control the temperature at 45°C, continue stirring for 5 hours; and then filter through a 0.5 μm filter membrane to obtain the final methanol fuel mother liquor additive.

[0044] The core innovations and beneficial effects of the present invention can be summarized as follows:

[0045] The present invention comprehensively improves the comprehensive performance of methanol fuel through a carefully designed multi-component synergistic system. The core of the present invention is to utilize the complementarity of molecular structure and the synergistic effect of functional groups to construct an efficient and environmentally friendly methanol fuel mother liquor additive system.

[0046] First, the oxygen-containing synergist selected in the present invention not only provides additional oxygen content, but more importantly, a compound with a specific electronic structure is selected under the guidance of molecular orbital theory. For example, the ether bond and hydroxyl group of 2-methoxyethanol can form a stable hydrogen bond network with methanol molecules, while the ring structure of tetrahydrofuran is conducive to improving the energy density of the fuel. This carefully designed combination not only significantly improves the octane number, but also improves the atomization characteristics of the fuel.

[0047] Secondly, the combustion improver system of the present invention cleverly utilizes the synergistic effect between molecules. Isooctyl nitrate can release active oxygen during combustion, while tetralin provides good ignition performance through its unique ring structure. The synergistic effect of these two compounds not only accelerates flame propagation, but also effectively reduces emissions.

[0048] Furthermore, the free radical regulator system of the present invention fully considers the free radical chain reaction mechanism in the combustion process. N,N'-di-sec-butyl-p-phenylenediamine and 2,4,6-trimethylphenol form an efficient free radical capture network through different action mechanisms, effectively controlling the combustion process and significantly improving the oxidation stability of the fuel.

[0049] In addition, the surfactant system of the present invention not only improves the atomization effect of the fuel, but also enhances the dispersibility of the additive in methanol through the combination of carefully selected non-ionic and ionic surfactants. This design makes full use of the hydrophobic and hydrophilic interactions between molecules to form a stable microstructure and effectively improve the low-temperature fluidity of the fuel.

[0050] Finally, the corrosion inhibitor system of the present invention adopts a multiple protection mechanism. 2-Mercaptobenzothiazole forms a protective film with the metal surface through sulfur atoms, benzotriazole uses its nitrogen atoms to coordinate with the metal, and EDTA effectively complexes metal ions through strong chelation. This multi-level protection mechanism greatly enhances the durability and effectiveness of the anti-corrosion effect.

[0051] The present invention achieves a number of unexpected technical effects through the above-mentioned carefully designed component formula and preparation process. Not only does it increase the octane number of methanol fuel to above 105, but it also improves the low-temperature fluidity to below -50°C. What is even more surprising is that the present invention significantly increases the combustion speed and comprehensively reduces harmful emissions. These outstanding performance improvements have cleared the technical barriers for the widespread application of methanol fuel in the automotive field.

[0052] In summary, the present invention has successfully developed an efficient and environmentally friendly methanol fuel mother liquor additive by deeply understanding the molecular structure and reaction mechanism and cleverly utilizing the synergistic effect between the components. This additive not only comprehensively improves the comprehensive performance of methanol fuel, but also provides new possibilities for solving energy and environmental problems, and has important theoretical significance and broad application prospects. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] Example 1

[0055] This embodiment provides a methanol fuel mother liquid additive, which comprises the following components in parts by weight:

[0056] 35 parts of oxygen-containing synergist, 20 parts of combustion improver, 15 parts of free radical regulator, 10 parts of surfactant, and 5 parts of corrosion inhibitor.

[0057] Among them, the oxygen-containing synergist consists of 15 parts of 2-methoxyethanol, 10 parts of tetrahydrofuran and 10 parts of 1,3-dioxolane. The combustion improver contains 10 parts of isooctyl nitrate, 5 parts of tetralin and 5 parts of methyl tert-butyl ether. The free radical regulator consists of 7 parts of N,N′-di-sec-butyl-p-phenylenediamine, 5 parts of 2,4,6-trimethylphenol and 3 parts of 4-methylpyridine. The surfactant includes 5 parts of sorbitan monooleate, 3 parts of sodium dodecyl sulfate and 2 parts of polyethylene glycol. The corrosion inhibitor consists of 2 parts of 2-mercaptobenzothiazole, 2 parts of benzotriazole and 1 part of ethylenediaminetetraacetic acid.

[0058] The preparation method of the methanol fuel mother liquid additive comprises the following steps:

[0059] (1) Preparation of oxygen-containing synergist: Add 2-methoxyethanol to a three-necked flask equipped with a mechanical stirrer and a condensing reflux device at 40°C, start stirring at a speed of 300 rpm. Then slowly add tetrahydrofuran and 1,3-dioxolane in sequence. Under nitrogen protection, raise the temperature to 45°C and react for 1.5 hours.

[0060] (2) Preparation of combustion improver: Add tetralin to a pressure-resistant reactor, set the temperature to 25°C, start stirring at 250 rpm. Then slowly add isooctyl nitrate, stir evenly, and then slowly add methyl tert-butyl ether. Raise the temperature to 60°C and react for 2.5 hours under inert gas protection.

[0061] (3) Preparation of free radical regulator: Add N,N′-di-sec-butyl-p-phenylenediamine to a three-necked flask, raise the temperature to 50°C, and stir at 300 rpm. Add 2,4,6-trimethylphenol and 4-methylpyridine in sequence. Raise the temperature to 55°C under a nitrogen atmosphere and react for 2.5 hours.

[0062] (4) Preparation of surfactant: Use a high shear emulsifier and set the temperature to 60°C. First add polyethylene glycol and start stirring at 400 rpm. Slowly add sorbitan monooleate and stir for 5 minutes before adding sodium lauryl sulfate. Continue high-speed shear mixing for 2 hours.

[0063] (5) Preparation of corrosion inhibitor: In a reaction kettle equipped with a pH meter, first add 10 parts of deionized water and adjust the pH to 7.0. Add ethylenediaminetetraacetic acid and stir to dissolve. Then add 2-mercaptobenzothiazole and benzotriazole in sequence. Keep the temperature at 50°C, stir at 250 rpm, and react for 1.5 hours.

[0064] (6) Final mixing: Add oxygen-containing enhancer to a large reactor equipped with a high-speed disperser and start stirring at a speed of 450 rpm. Then slowly add combustion improver, free radical regulator, surfactant and corrosion inhibitor in sequence, stirring for 10 minutes after each component is added. Finally, under nitrogen protection, control the temperature at 45°C and continue stirring for 5 hours. Then filter through a 0.5 μm filter membrane to obtain the final methanol fuel mother liquor additive.

[0065] Example 2

[0066] The methanol fuel mother liquid additive provided in this embodiment is composed of the following (parts by weight):

[0067] 40 parts of oxygen-containing synergist, 25 parts of combustion improver, 20 parts of free radical regulator, 15 parts of surfactant, and 7.5 parts of corrosion inhibitor.

[0068] Among them, the oxygen-containing synergist consists of 17.5 parts of 2-methoxyethanol, 12.5 parts of tetrahydrofuran and 10 parts of 1,3-dioxolane. The combustion improver contains 12.5 parts of isooctyl nitrate, 6.5 parts of tetralin and 6 parts of methyl tert-butyl ether. The free radical regulator consists of 8.5 parts of N,N′-di-sec-butyl-p-phenylenediamine, 6.5 parts of 2,4,6-trimethylphenol and 5 parts of 4-methylpyridine. The surfactant includes 6.5 parts of sorbitan monooleate, 4.5 parts of sodium dodecyl sulfate and 4 parts of polyethylene glycol. The corrosion inhibitor consists of 3 parts of 2-mercaptobenzothiazole, 2.5 parts of benzotriazole and 2 parts of ethylenediaminetetraacetic acid.

[0069] The preparation method is similar to that of Example 1, but different parameters are used in each step:

[0070] In step (1), the reaction temperature is 45°C, the stirring speed is 350 rpm, and the reaction time is 1.75 hours. In step (2), the initial temperature is 27°C, the final temperature is 65°C, and the reaction time is 2.75 hours. In step (3), the initial temperature is 52°C, the final temperature is 57°C, and the reaction time is 2.75 hours. In step (4), the temperature is 62°C, the stirring speed is 425 rpm, and the mixing time is 2.25 hours. In step (5), 12.5 parts of deionized water are used, the temperature is 52°C, the stirring speed is 275 rpm, and the reaction time is 1.75 hours. Finally, in step (6), the stirring speed is 475 rpm, and the final stirring time is 5.5 hours.

[0071] Example 3

[0072] The methanol fuel mother liquid additive composition of the present embodiment is as follows (parts by weight):

[0073] 45 parts of oxygen-containing synergist, 30 parts of combustion improver, 25 parts of free radical regulator, 20 parts of surfactant, and 10 parts of corrosion inhibitor.

[0074] Among them, the oxygen-containing synergist consists of 20 parts of 2-methoxyethanol, 15 parts of tetrahydrofuran and 10 parts of 1,3-dioxolane. The combustion improver contains 15 parts of isooctyl nitrate, 8 parts of tetralin and 7 parts of methyl tert-butyl ether. The free radical regulator consists of 10 parts of N,N′-di-sec-butyl-p-phenylenediamine, 8 parts of 2,4,6-trimethylphenol and 7 parts of 4-methylpyridine. The surfactant includes 8 parts of sorbitan monooleate, 6 parts of sodium dodecyl sulfate and 6 parts of polyethylene glycol. The corrosion inhibitor consists of 4 parts of 2-mercaptobenzothiazole, 3 parts of benzotriazole and 3 parts of ethylenediaminetetraacetic acid.

[0075] The preparation method is similar to the previous two embodiments, but the parameters are adjusted:

[0076] In step (1), the reaction temperature is 50°C, the stirring speed is 400rpm, and the reaction time is 2 hours. In step (2), the initial temperature is 30°C, the final temperature is 70°C, and the reaction time is 3 hours. In step (3), the initial temperature is 55°C, the final temperature is 60°C, and the reaction time is 3 hours. In step (4), the temperature is 65°C, the stirring speed is 450rpm, and the mixing time is 2.5 hours. In step (5), 15 parts of deionized water are used, the temperature is 55°C, the stirring speed is 300rpm, and the reaction time is 2 hours. Finally, in step (6), the stirring speed is 500rpm and the final stirring time is 6 hours.

[0077] Example 4

[0078] The methanol fuel mother liquid additive composition of the present embodiment is as follows (parts by weight):

[0079] 42.5 parts of oxygen-containing synergist, 27.5 parts of combustion improver, 22.5 parts of free radical regulator, 17.5 parts of surfactant, and 8.75 parts of corrosion inhibitor.

[0080] Among them, the oxygen-containing synergist consists of 18.75 parts of 2-methoxyethanol, 13.75 parts of tetrahydrofuran and 10 parts of 1,3-dioxolane. The combustion improver contains 13.75 parts of isooctyl nitrate, 7.25 parts of tetralin and 6.5 parts of methyl tert-butyl ether. The free radical regulator consists of 9.25 parts of N,N′-di-sec-butyl-p-phenylenediamine, 7.25 parts of 2,4,6-trimethylphenol and 6 parts of 4-methylpyridine. The surfactant includes 7.25 parts of sorbitan monooleate, 5.25 parts of sodium dodecyl sulfate and 5 parts of polyethylene glycol. The corrosion inhibitor consists of 3.5 parts of 2-mercaptobenzothiazole, 2.75 parts of benzotriazole and 2.5 parts of ethylenediaminetetraacetic acid.

[0081] The preparation method parameters are as follows:

[0082] In step (1), the reaction temperature is 47.5°C, the stirring speed is 375rpm, and the reaction time is 1.875 hours. In step (2), the initial temperature is 28.5°C, the final temperature is 67.5°C, and the reaction time is 2.875 hours. In step (3), the initial temperature is 53.5°C, the final temperature is 58.5°C, and the reaction time is 2.875 hours. In step (4), the temperature is 63.5°C, the stirring speed is 437.5rpm, and the mixing time is 2.375 hours. In step (5), 13.75 parts of deionized water are used, the temperature is 53.5°C, the stirring speed is 287.5rpm, and the reaction time is 1.875 hours. Finally, in step (6), the stirring speed is 487.5rpm, and the final stirring time is 5.75 hours.

[0083] Comparative Example 1: Methanol fuel mother liquor additive containing a single oxygen-containing synergist

[0084] This comparative example is intended to verify the synergistic effect of the oxygen-containing synergist component and is compared with Example 1. Its composition is as follows:

[0085] 35 parts of oxygen-containing synergist (only 2-methoxyethanol is used), 20 parts of combustion improver, 15 parts of free radical regulator, 10 parts of surfactant, and 5 parts of corrosion inhibitor.

[0086] The preparation method is the same as that of Example 1, except that only 2-methoxyethanol is added in step (1). The other steps remain unchanged.

[0087] Comparative Example 2: Methanol fuel mother liquor additive lacking combustion improver

[0088] This comparative example is intended to verify the importance of the combustion improver and is compared with Example 2. Its composition is as follows:

[0089] 40 parts of oxygen-containing synergist, 20 parts of free radical regulator, 15 parts of surfactant, and 7.5 parts of corrosion inhibitor.

[0090] The preparation method is the same as that of Example 2, except that step (2) is omitted. The parameters of the other steps remain unchanged.

[0091] Comparative Example 3: Methanol fuel mother liquor additive replacing free radical regulator

[0092] This comparative example is intended to verify the unique effect of the free radical regulator selected in the present invention, and is compared with Example 3. Its composition is as follows:

[0093] 45 parts of oxygen-containing synergist, 30 parts of combustion improver, 25 parts of free radical regulator (replaced by conventional antioxidant such as butylated hydroxyanisole), 20 parts of surfactant, and 10 parts of corrosion inhibitor.

[0094] The preparation method is similar to that of Example 3, except that butylated hydroxyanisole is used in step (3) to replace the original free radical regulator combination. The parameters of the other steps remain unchanged.

[0095] Comparative Example 4: Methanol fuel mother liquor additive lacking surfactant

[0096] This comparative example is intended to verify the effect of the surfactant on the fuel performance and is compared with Example 4.

[0097] Its composition is as follows:

[0098] 42.5 parts of oxygen-containing synergist, 27.5 parts of combustion improver, 22.5 parts of free radical regulator, and 8.75 parts of corrosion inhibitor.

[0099] The preparation method is the same as that of Example 4, except that step (4) is omitted. The parameters of the other steps remain unchanged.

[0100] Comparative Example 5: Methanol fuel mother liquor additive with adjusted component ratio

[0101] This comparative example is intended to verify the superiority of the component ratio selected in the present invention, and is compared with Example 1.

[0102] Its composition is as follows:

[0103] 50 parts of oxygen-containing enhancer, 10 parts of combustion improver, 30 parts of free radical regulator, 5 parts of surfactant, and 5 parts of corrosion inhibitor.

[0104] The preparation method is the same as that of Example 1, but the amount of each component is adjusted according to the above ratio. The parameters of other steps remain unchanged.

[0105] Comparative Example 6: Methanol fuel mother liquor additive with changed preparation process

[0106] This comparative example is intended to verify the importance of the preparation process of the present invention and is compared with Example 2. Its composition is the same as that of Example 2, but the preparation method is changed:

[0107] (1) Preparation of oxygen-containing enhancer: The temperature was raised to 70°C, the stirring speed was reduced to 200 rpm, and the reaction time was shortened to 1 hour.

[0108] (2) Preparation of combustion improver: The initial temperature was raised to 40°C, the final temperature was lowered to 50°C, and the reaction time was extended to 4 hours.

[0109] (3) Preparation of free radical regulator: The initial temperature was lowered to 40°C, the final temperature was increased to 70°C, and the reaction time was shortened to 1.5 hours.

[0110] (4) Preparation of surfactant: The temperature was lowered to 50°C, the stirring speed was increased to 500 rpm, and the mixing time was extended to 3 hours.

[0111] (5) Preparation of corrosion inhibitor: 15 parts of deionized water were used, the temperature was increased to 60° C., the stirring speed was reduced to 200 rpm, and the reaction time was extended to 2.5 hours.

[0112] (6) Final mixing: The stirring speed was reduced to 400 rpm and the final stirring time was shortened to 4 hours.

[0113] Through these six comparative examples, the synergistic effect of the components of the present invention and the importance of the preparation process can be fully evaluated. Comparative Examples 1-4 respectively verify the synergistic effect of the oxygen-containing synergist, the necessity of the combustion improver, the unique role of the free radical regulator and the importance of the surfactant. Comparative Example 5 proves the superiority of the ratio selected by the present invention by adjusting the component ratio. Finally, Comparative Example 6 highlights the importance of the process parameters of the present invention by changing the preparation process.

[0114] By comparing with the corresponding embodiments, the innovative points and technical effects of the present invention can be comprehensively evaluated, providing strong support for the creativity of the present invention.

[0115] In order to comprehensively evaluate the performance of the methanol fuel mother solution additive of the present invention and the effectiveness of its preparation method, a series of test experiments were designed to verify the core innovation of the present invention and demonstrate the synergistic mechanism of each component.

[0116] Experiment 1: Octane number determination

[0117] Experimental method: ASTM D2699 standard method was used to determine the research octane number (RON) using a CFR engine.

[0118] Experimental conditions: ambient temperature 25°C, relative humidity 60%, atmospheric pressure 101.3 kPa.

[0119] Experiment 2: Low temperature fluidity test

[0120] Experimental method: The pour point of the fuel was determined according to ASTM D97 standard.

[0121] Experimental conditions: Use a low temperature thermostat with a temperature range of -60°C to 0°C and a cooling rate of 3°C / h.

[0122] Experiment 3: Fuel Stability Assessment

[0123] Experimental method: According to ASTM D525 standard, the oxidation stability of fuel is determined.

[0124] Experimental conditions: temperature 100°C, oxygen pressure 700 kPa, test time until the pressure drops.

[0125] Experiment 4: Corrosion Test

[0126] Experimental method: Conduct copper sheet corrosion test according to ASTM D130 standard.

[0127] Experimental conditions: temperature 50°C, test time 3 hours.

[0128] Experiment 5: Combustion Characteristics Analysis

[0129] Experimental method: Using a high-speed camera and a pressure sensor, the combustion pressure and flame propagation speed were measured on a single-cylinder engine.

[0130] Experimental conditions: engine speed 1500 rpm, load 50%, ignition advance angle 15° BTDC.

[0131] Experiment 6: Emission Test

[0132] Experimental method: According to the requirements of Euro VI emission standards, the WLTC cycle test is carried out on a chassis dynamometer.

[0133] Experimental conditions: ambient temperature 25°C, relative humidity 45%, atmospheric pressure 101.3 kPa.

[0134] The test results are shown in the following table:

[0135]

[0136]

[0137] According to the test results, Example 3 exhibits the best comprehensive performance and can be regarded as the best embodiment of the present invention.

[0138] By analyzing the test data, we can deeply explore the unexpected technical effects of the present invention:

[0139] 1. Ultra-high octane number: The RON of Examples 2-4 all exceeded 103, which is much higher than that of conventional methanol gasoline. This may be due to the synergistic effect of 2-methoxyethanol, tetrahydrofuran and 1,3-dioxolane in the oxygen-containing synergist, which not only provide additional oxygen content, but also may form a special intermolecular effect, enhancing the anti-knock performance of the fuel.

[0140] 2. Excellent low-temperature fluidity: The pour point of all examples is below -45°C, which is far beyond expectations. This may be due to the synergistic effect of sorbitan monooleate and polyethylene glycol in the surfactant component, which forms a special microstructure and effectively inhibits the formation of crystals at low temperatures.

[0141] 3. Excellent oxidation stability: The oxidation stability of the examples generally exceeds 720 minutes, which is much better than conventional additives. This may be due to the synergistic effect of N,N′-di-sec-butyl-p-phenylenediamine and 2,4,6-trimethylphenol in the free radical regulator, which may form an efficient free radical capture network, significantly delaying the oxidation process of the fuel.

[0142] 4. Significantly improved combustion speed: The flame propagation speed of the examples is generally higher than 38 m / s. This performance improvement may be due to the synergistic effect of isooctyl nitrate and tetralin in the combustion improver. They may form active intermediates during the combustion process, accelerating the propagation of the chain reaction.

[0143] 5. Overall reduced emissions: CO, HC and NOx emissions of all examples are significantly lower than those of the comparative examples. This effect may be due to the combined effects of the various components, especially the oxygen-containing synergist improves combustion completeness, the free radical regulator optimizes the combustion process, and the surfactant improves the fuel atomization quality.

[0144] 6. Excellent anti-corrosion performance: The examples all obtained grade 1a in the copper sheet corrosion test, which is better than all the comparative examples. This may be due to the synergistic effect of 2-mercaptobenzothiazole, benzotriazole and EDTA in the corrosion inhibitor, which may form a multi-layer protection network and effectively prevent the corrosion process of the metal surface.

[0145] These unexpected technical effects fully demonstrate the synergy between the components of the present invention, as well as the importance of carefully designed formula ratios and preparation processes. The present invention not only significantly improves the comprehensive performance of methanol fuel, but also makes a breakthrough in environmental performance, providing new possibilities for the wide application of methanol fuel in the automotive field.

[0146] In order to comprehensively evaluate the innovation and superiority of the methanol fuel mother liquor additive of the present invention, the following series of professional test experiments are carefully designed.

[0147] First, a water solubility test was conducted. This test is designed to evaluate the effect of additives on the water resistance of methanol fuel, which is a key challenge facing methanol fuel. The ASTMD1094 standard was used to measure the phase separation of fuels at different water contents (0.1%-2%) in the temperature range of 0-40°C. The specific steps include mixing the fuel sample with a specific proportion of water, balancing in a constant temperature water bath for 2 hours, and observing and recording the phase separation.

[0148] Secondly, the atomization characteristics analysis was carried out. The purpose of this test is to evaluate the effect of additives on the fuel atomization effect, which is directly related to combustion efficiency and emission performance. Using a laser particle size analyzer, the particle size distribution of the fuel droplets after injection was measured at an injection pressure of 150 bar and an ambient temperature of 25°C. During the test, data at multiple time points were collected to fully understand the dynamic changes in the atomization process.

[0149] Next, a cold start performance test was conducted. This test is designed to evaluate the impact of additives on the cold start performance of the engine, which is an important challenge faced by methanol fuel in practical applications. The engine start time and stability were tested in three low temperature environments of -20℃, -30℃ and -40℃. During the test, the time required for the engine to start, idle stability and emissions were recorded.

[0150] Finally, a long-term storage stability test was conducted. The purpose of this test is to evaluate the effect of additives on the long-term storage stability of the fuel, which is crucial for the practical application of methanol fuel. The fuel samples were sealed and stored at 40°C for 6 months, and samples were taken monthly to analyze changes in their physical and chemical properties, including acid value indicators.

[0151] The test results are shown in the following table:

[0152]

[0153]

[0154] By analyzing these test data, we can deeply explore the multiple unexpected technical effects of the present invention.

[0155] First, the present invention exhibits excellent water resistance. The phase separation temperature of Example 3 is as low as -10°C, which means that even in a low temperature environment, the additive-treated fuel can still effectively resist the influence of moisture. This significant improvement may be due to the synergistic effect of the surfactant components, which may form a special microstructure at the molecular level, effectively preventing the interaction between water molecules and methanol molecules. This discovery provides a new idea for solving the hygroscopicity problem of methanol fuel.

[0156] Secondly, the present invention achieves excellent atomization effect. The average droplet size of Example 3 is only 11 μm, which is much smaller than that of the comparative example. This significant improvement may be due to the synergistic effect of the oxygen-containing enhancer and the surfactant, which may reduce the surface tension of the fuel and improve the viscosity characteristics of the fuel. This discovery opens up a new way to improve the combustion efficiency of methanol fuel.

[0157] Third, the present invention significantly improves the cold start performance. Under the harsh conditions of -30°C, the cold start time of Example 3 is only 2.5 seconds, which is much better than the comparative example. This excellent low-temperature performance may be due to the synergistic effect of the combustion improver and the free radical regulator, which may still be able to quickly form active intermediates at low temperatures to promote the ignition and combustion of the fuel. This discovery provides a new solution to the problem of low-temperature application of methanol fuel.

[0158] Finally, the present invention exhibits excellent long-term storage stability. After 6 months of accelerated aging test, the acid value increase of Example 3 is only 0.05 mgKOH / g, which is much lower than the comparative example. This significant improvement in stability may be due to the synergistic effect of the free radical regulator and the antioxidant, which may form an efficient free radical capture network, effectively inhibiting the oxidation and degradation process of the fuel. This discovery provides a new method for improving the storage stability of methanol fuel.

[0159] In summary, the present invention has made breakthrough progress in improving water resistance, improving atomization effect, optimizing cold start performance and enhancing long-term storage stability through a carefully designed multi-component synergistic system. These unexpected technical effects not only comprehensively improve the comprehensive performance of methanol fuel, but also clear technical obstacles for the application of methanol fuel under various harsh conditions, fully demonstrating the innovation and superiority of the present invention.

[0160] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A methanol fuel mother liquor additive, characterized in that: The composition comprises the following components in parts by weight: A. 35-45 parts of oxygen-containing synergist; B. 20-30 parts of combustion improver; C. 15-25 parts of free radical regulator; D. 10-20 parts of surfactant; E. Corrosion inhibitor 5-10 parts.

2. The methanol fuel mother liquid additive according to claim 1, characterized in that: The oxygen-containing synergist comprises: 2-methoxyethanol 15-20 parts; 10-15 parts of tetrahydrofuran; 1,3-dioxolane 10-12 parts.

3. The methanol fuel mother liquid additive according to claim 1, characterized in that: The combustion improver comprises: 10-15 parts of 2-ethylhexyl nitrate; 5-8 parts of tetralin; 5-7 parts of methyl tert-butyl ether.

4. The methanol fuel mother liquid additive according to claim 1, characterized in that: The free radical regulator includes: 7-10 parts of N,N′-di-sec-butyl-p-phenylenediamine; 2,4,6-trimethylphenol 5-8 parts; 3-7 parts of 4-methylpyridine.

5. The methanol fuel mother liquid additive according to claim 1, characterized in that: The surfactant includes: 5-8 parts of sorbitan monooleate; 3-6 parts of sodium lauryl sulfate; 2-6 parts of polyethylene glycol.

6. The methanol fuel mother liquid additive according to claim 1, characterized in that: The corrosion inhibitors include: 2-Mercaptobenzothiazole 2-4 parts; 2-3 parts of benzotriazole; 1-3 parts of ethylenediaminetetraacetic acid.

7. A method for preparing the methanol fuel mother liquid additive according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) preparing an oxygen-containing synergist; (2) preparing combustion improver; (3) preparing a free radical regulator; (4) preparing a surfactant; (5) Preparation of corrosion inhibitors; (6) Mixing the products obtained in steps (1) to (5) to obtain the methanol fuel mother liquid additive.

8. The preparation method according to claim 7, characterized in that: In step (1), first, at 40-50° C., 2-methoxyethanol is added to a three-necked flask equipped with a mechanical stirrer and a condensing reflux device, and stirring is started at a speed of 300 rpm; then tetrahydrofuran and 1,3-dioxolane are slowly added in sequence; under nitrogen protection, the temperature is raised to 45° C. and the reaction is carried out for 1.5 hours.

9. The preparation method according to claim 7, characterized in that: In step (2), tetralin is first added to a pressure-resistant reactor, the temperature is set to 25° C., stirring is started at a speed of 250 rpm; then isooctyl nitrate is slowly added; after stirring evenly, methyl tert-butyl ether is slowly added; the temperature is raised to 60° C., and the reaction is carried out under the protection of an inert gas for 2.5 hours.

10. The preparation method according to claim 7, characterized in that: In step (6), firstly, add the oxygen-containing enhancer to a large reactor equipped with a high-speed disperser, start stirring at a speed of 450 rpm; then slowly add the combustion improver, free radical regulator, surfactant and corrosion inhibitor in sequence, stirring for 10 minutes after each component is added; finally, under nitrogen protection, control the temperature at 45°C, continue stirring for 5 hours; and then filter through a 0.5 μm filter membrane to obtain the final methanol fuel mother liquor additive.

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