Methanol fuel additive for direct injection engine and preparation method of methanol fuel additive

Abstract

The invention provides a methanol fuel additive for a direct injection engine and a preparation method of the methanol fuel additive, and belongs to the technical field of fuel additives. The lubricating agent is composed of the following components in percentage by weight: 40-50% of lubricating agent, which is composed of iso-tridecanol adipate and isooctyl palmitate according to a mass ratio of 2: 1; 30%-45% of a purification dispersant composed of polyether amine and polyisobutylene succinimide according to a mass ratio of 4: 1; 1%-3% of a metal corrosion inhibitor which is benzotriazole fatty acid amine salt; 1%-3% of an antioxidant, wherein the antioxidant is N-phenyl-alpha-naphthylamine; the solvent is composed of diethyl ether and 2-alkyl-1-alkanol according to the mass ratio of 1: 1. By optimizing the synergistic effect of the components, the lubricating property, corrosion resistance and cleanliness of the additive are balanced, the problems of abrasion and corrosion of parts and blockage of an oil injection system during operation of an M100 methanol direct injection engine can be solved, and the engine can operate stably.

Description

Technical Field

[0001] The invention provides a methanol fuel additive for a direct injection engine and a preparation method thereof, belonging to the technical field of fuel additives. Background Art

[0002] As a clean alternative fuel, methanol has the advantages of wide sources, high combustion efficiency and low emission pollution. However, it has poor lubricity and is corrosive to metal parts. As an alternative fuel for engines, it can easily cause wear of engine parts and blockage of the fuel injection system.

[0003] Existing methanol additives are mostly designed for naturally aspirated engines and cannot meet the stringent lubricity, corrosion resistance, and cleanliness requirements of direct injection engines. Direct injection engines utilize high-pressure injection systems. Under these high-pressure injection conditions, methanol fuel is more likely to cause wear and corrosion of key components such as the plunger and nozzle, as well as the formation of high-temperature deposits, leading to engine failure.

[0004] Therefore, in view of this, the existing structure is studied and improved, and a methanol fuel additive for a direct injection engine and a preparation method thereof are proposed to solve the above-mentioned problems. Summary of the Invention

[0005] The present invention discloses a methanol fuel additive for a direct injection engine and a preparation method thereof, which balances the lubricity, corrosion resistance and detergency of the additive by optimizing the synergistic effect of the components. The additive can solve the problems of component wear and corrosion and fuel injection system blockage that occur during the operation of an M100 methanol direct injection engine, thereby ensuring stable operation of the engine.

[0006] In order to solve the above problems, the present invention proposes a technical solution: a methanol fuel additive for direct injection engines and a preparation method thereof, which comprises the following components by weight percentage:

[0007] 40%-50% lubricant, composed of isotridecyl adipate and isooctyl palmitate in a mass ratio of 2:1;

[0008] 30%-45% detergent dispersant, composed of polyetheramine and polyisobutylene succinimide in a mass ratio of 4:1;

[0009] 1%-3% metal corrosion inhibitor, which is benzotriazole fatty acid amine salt;

[0010] Antioxidant 1%-3%, N-phenyl-α-naphthylamine;

[0011] The solvent is 10%-15%, and is composed of diethyl ether and 2-alkyl-1-alkanol in a mass ratio of 1:1.

[0012] Furthermore, the molecular structural formula of the isomeric tridecyl adipate in the lubricant is C13H27OOC(CH2)4COOC13H27, and the molecular structural formula of isooctyl palmitate is CH3(CH2)14COOCH2CH(C2H5)(CH2)3CH3.

[0013] Furthermore, the number average molecular weight of the polyetheramine in the detergent dispersant is 1000-2000, and the number average molecular weight of the polyisobutylene succinimide is 800-1500.

[0014] Furthermore, the metal corrosion inhibitor is a reaction product of benzotriazole and C8-C18 fatty acid amine.

[0015] Furthermore, the purity of the antioxidant N-phenyl-α-naphthylamine is ≥98%.

[0016] Furthermore, the 2-alkyl-1-alkanol in the solvent is 2-butyl-1-octanol or 2-hexyl-1-decanol.

[0017] Further, the following steps are included:

[0018] Mix the solvent, lubricant and metal corrosion inhibitor at 50-60°C;

[0019] Add detergent dispersant and antioxidant, maintain temperature and continue stirring;

[0020] The finished product is obtained by cooling and filtering.

[0021] Furthermore, the stirring speed is 200-400 rpm, and the filtration adopts a 5-10 μm filter element.

[0022] Furthermore, the injection pressure of the engine is ≥200 bar, and the compression ratio is 10:1-18:1.

[0023] Due to the adoption of the above technical solution, the beneficial effects of the methanol fuel additive for direct injection engines and the preparation method thereof of the present invention are as follows:

[0024] 1. The present invention uses a specific ratio of ester lubricant combination (isotridecyl adipate and isooctyl palmitate) to form a stable oil film under high-pressure injection conditions, reducing the friction torque value by more than 20% compared with pure methanol, effectively solving the wear problem of key components such as the plunger and nozzle caused by methanol fuel.

[0025] 2. The present invention adopts a compound system of polyetheramine and polyisobutylene succinimide to synergistically inhibit carbon deposits and colloid formation. After 200 hours of bench testing, the nozzle flow rate change rate is ≤7% (competitive products reach 25%), significantly reducing the clogging risk of direct injection engines. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. It is obvious that the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0027] The present invention provides a methanol fuel additive for a direct injection engine and a preparation method thereof. The additive comprises the following components by weight:

[0028] 40%-50% lubricant, composed of isotridecyl adipate and isooctyl palmitate in a mass ratio of 2:1;

[0029] 30%-45% detergent dispersant, composed of polyetheramine and polyisobutylene succinimide in a mass ratio of 4:1;

[0030] 1%-3% metal corrosion inhibitor, which is benzotriazole fatty acid amine salt;

[0031] Antioxidant 1%-3%, N-phenyl-α-naphthylamine;

[0032] The solvent is 10%-15%, and is composed of diethyl ether and 2-alkyl-1-alkanol in a mass ratio of 1:1.

[0033] The molecular structural formula of isomeric tridecyl adipate in the lubricant is C13H27OOC(CH2)4COOC13H27, and the molecular structural formula of isooctyl palmitate is CH3(CH2)14COOCH2CH(C2H5)(CH2)3CH3.

[0034] The number average molecular weight of the polyetheramine in the detergent dispersant is 1000-2000, and the number average molecular weight of the polyisobutylene succinimide is 800-1500.

[0035] The metal corrosion inhibitor is a reaction product of benzotriazole and a C8-C18 fatty acid amine.

[0036] The purity of the antioxidant N-phenyl-α-naphthylamine is ≥98%.

[0037] The 2-alkyl-1-alkanol in the solvent is 2-butyl-1-octanol or 2-hexyl-1-decanol.

[0038] The following steps are involved:

[0039] Mix the solvent, lubricant and metal corrosion inhibitor at 50-60°C with a stirring speed of 200-400 rpm and filter with a 5-10 μm filter element;

[0040] Add detergent dispersant and antioxidant, maintain temperature and continue stirring;

[0041] The finished product is obtained by cooling and filtering.

[0042] The injection pressure of the engine is ≥200 bar, and the compression ratio is 10:1-18:1.

[0043] Example 1:

[0044] 15% by mass of ether and 2-alkyl-1-alkanol (mass ratio of 1:1), 40% of isotridecyl adipate and isooctyl palmitate (mass ratio of 2:1), and 1% of benzotriazole fatty acid amine salt were added to a blending axe, heated to 55°C, and stirred evenly. 41% of polyetheramine and polyisobutylene succinimide (mass ratio of 4:1) and 3% of N-phenyl-α-naphthylamine were then added to the reactor. The temperature was maintained at 55°C, blended for 1 hour, cooled, and filtered to obtain product T1.

[0045] Example 2:

[0046] 13% by mass of ether and 2-alkyl-1-alkanol (mass ratio of 1:1), 45% of isotridecyl adipate and isooctyl palmitate (mass ratio of 2:1), and 2% of benzotriazole fatty acid amine salt were added to a blending axe, heated to 55°C, and stirred evenly. Then, 38% of polyetheramine and polyisobutylene succinimide (mass ratio of 4:1) and 2% of N-phenyl-α-naphthylamine were added to the reactor, maintained at 55°C, blended for 1 hour, cooled, and filtered to obtain product T2.

[0047] Example 3:

[0048] Add 10% by mass of ether and 2-alkyl-1-alkanol (1:1 mass ratio), 50% of isotridecyl adipate and isooctyl palmitate (2:1 mass ratio), and 3% of benzotriazole fatty acid amine salt to a blending axe, heat to 55°C, and stir evenly. Then, add 36% of polyetheramine and polyisobutylene succinimide (4:1 mass ratio) and 1% of N-phenyl-α-naphthylamine to the reactor, maintain the temperature at 55°C, blend for 1 hour, cool, and filter to obtain product T3.

[0049] The physical and chemical indicators of Examples 1-3 of the present invention were tested, as shown in Table 1.

[0050] Table 1 M100 methanol additive test indicators

[0051]

[0052]

[0053] Examples 1-3 of the present invention and competing products were subjected to rust resistance testing according to Appendix A of GB / T 42436. The test method is as follows: an aluminum sheet was completely immersed in a mixture of 30 mL of methanol, 0.5% formic acid, 0.5% distilled water, and 0.5% M100 methanol fuel additive at (38 ± 1)°C for 15 hours. The aluminum sheet was observed for signs of rust and the extent of rust. Examples 1-3 and the competing products were added to premium methanol at a ratio of 1000 ppm to form M100 methanol fuel. The lubricity of the M100 methanol fuel was tested using the torque test method. The test results are shown in Table 2.

[0054] Table 2 Lubricity and rust resistance test

[0055]

[0056] Examples 1-3 were tested on a methanol engine high-pressure common rail bench using 1000 ppm of the additive added to premium methanol. Under a rail pressure of 700 bar, the common rail pumps of Examples 1, 2, and 3 all operated stably for over 1000 hours. Under the same operating conditions, a competitive product was bench tested and experienced seizure after 200 hours. Using pure methanol, seizure occurred after 16 hours.

[0057] The present invention provides an M100 methanol fuel additive suitable for direct-injection methanol engines by combining preferred lubricants, metal corrosion inhibitors, detergents and dispersants, antioxidants, and solvent components. The M100 methanol fuel additive of the present invention has excellent lubricity, detergents and dispersivities, antioxidant properties, and good low-temperature performance, and can effectively address the problems of insufficient lubricity, corrosion resistance, and detergent properties encountered by M100 methanol fuel during use in high-pressure injection engines. The preferred lubricant is composed of isotridecyl adipate and isooctyl palmitate. The isotridecyl adipate has excellent lubricity and stability, a low pour point, good solubility, and can be dissolved in various solvents, improving the compatibility of the formulation. The isooctyl palmitate has a short carbon chain and a large number of ester groups per unit area, resulting in excellent lubricity and the ability to form a strong oil film between frictional elements. It also has good combustion cleanliness, with little carbon residue and no coking after combustion and decomposition. Benzotriazole fatty acid amine salt, a metal corrosion inhibitor, has excellent antioxidant and rust-proof properties, enhancing the corrosion inhibition of fuel on metals such as aluminum, tin, and copper. The detergent dispersant is composed of polyetheramine and polyisobutylene succinimide. The polyetheramine exhibits excellent cleaning and dispersing properties, adsorbing small solid particles such as carbon deposits and varnish, preventing the formation of deposits. The polyisobutylene succinimide exhibits excellent dispersibility, inhibiting the polymerization of unstable components in fuel oil and preventing the formation of colloids. The combination of the two helps maintain combustion chamber cleanliness. The antioxidant N-phenyl-α-naphthylamine exhibits excellent thermal stability. When combined with the benzotriazole fatty acid amine salt, it improves fuel stability while reducing the swelling effect of the fuel on rubber components. The solvent, composed of ether and 2-alkyl-1-alkanol, enhances compatibility between the individual agents. The 2-alkyl-1-alkanol exhibits excellent lubricity, further enhancing the lubricity of the formulation. The present invention is free of halogens, sulfur, phosphorus, and metal compounds, reducing harmful gas emissions.

[0058] The present invention and its implementation methods are described above. This description is not restrictive. In short, if ordinary technicians in this field are inspired by it and do not depart from the purpose of the invention, they can creatively design structures and embodiments similar to the technical solution, which should fall within the scope of protection of the present invention.

Claims

1. A methanol fuel additive for a direct injection engine and a preparation method thereof, characterized in that: The components are as follows by weight: 40%-50% lubricant, composed of isotridecyl adipate and isooctyl palmitate in a mass ratio of 2:1; 30%-45% detergent dispersant, composed of polyetheramine and polyisobutylene succinimide in a mass ratio of 4:1; 1%-3% metal corrosion inhibitor, which is benzotriazole fatty acid amine salt; Antioxidant 1%-3%, N-phenyl-α-naphthylamine; The solvent is 10%-15%, and is composed of diethyl ether and 2-alkyl-1-alkanol in a mass ratio of 1:

1.

2. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, characterized in that: The molecular structural formula of isomeric tridecyl adipate in the lubricant is C13H27OOC(CH2)4COOC13H27, and the molecular structural formula of isooctyl palmitate is CH3(CH2)14COOCH2CH(C2H5)(CH2)3CH3.

3. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, characterized in that: The number average molecular weight of the polyetheramine in the detergent dispersant is 1000-2000, and the number average molecular weight of the polyisobutylene succinimide is 800-1500.

4. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, characterized in that: The metal corrosion inhibitor is a reaction product of benzotriazole and a C8-C18 fatty acid amine.

5. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, characterized in that: The purity of the antioxidant N-phenyl-α-naphthylamine is ≥98%.

6. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, characterized in that: The 2-alkyl-1-alkanol in the solvent is 2-butyl-1-octanol or 2-hexyl-1-decanol.

7. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, characterized in that: The following steps are involved: Mix the solvent, lubricant and metal corrosion inhibitor at 50-60°C; Add detergent dispersant and antioxidant, maintain temperature and continue stirring; The finished product is obtained by cooling and filtering.

8. A methanol fuel additive for a direct injection engine and a preparation method thereof according to claim 7, wherein the stirring speed is 200-400 rpm and the filtration adopts a 5-10 μm filter element.

9. The methanol fuel additive for a direct injection engine and the preparation method thereof according to claim 1, wherein the injection pressure of the engine is ≥200 bar and the compression ratio is 10:1-18:1.

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