Cylinder oil composition suitable for methanol fuel ship and preparation method of cylinder oil composition

Abstract

The invention provides a cylinder oil composition suitable for a methanol fuel ship and a preparation method of the cylinder oil composition, and particularly relates to the technical field of lubricating oil. The cylinder oil composition suitable for the methanol fuel ship comprises the following components in percentage by mass: 5.0%-20% of a clearing agent, 1.0%-8.0% of an ashless dispersant, 0.5%-1.5% of a composite antioxidant, 0.5%-3% of an anti-wear agent, 0.01%-1% of a metal deactivator and the balance of base oil, the detergent is composed of high-base-number synthetic calcium sulfonate, low-base-number synthetic calcium sulfonate, high-base-number calcium boride sulfonate and high-base-number sulfurized calcium alkyl phenolate. According to the cylinder oil composition for the methanol fuel ship, the scheme of the purification dispersant is optimized, and a plurality of components such as the metal deactivator are introduced for combination, so that the obtained cylinder oil composition for the methanol fuel ship improves the wear resistance and the corrosion resistance of an oil product when the oil product is polluted by methanol and formic acid, and can meet the performance requirements when a marine two-stroke engine uses methanol fuel.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, and more specifically, to a cylinder oil composition suitable for methanol-fueled marine applications and its preparation method. Background Technology

[0002] In recent years, to reduce greenhouse gas emissions, the International Maritime Organization (IMO) has set decarbonization targets for shipping. Researching and implementing large-scale applications of low-carbon / zero-carbon alternative fuels for ships is essential to fundamentally solving the problem of greenhouse gas emissions from shipping. Methanol, as a new type of low-carbon fuel, is receiving increasing attention, and the application of two-stroke methanol engines for marine use is also gradually increasing. Methanol has the characteristics of low viscosity and high latent heat of vaporization. Methanol and its incomplete combustion product, formic acid, can easily corrode cylinder liners. Methanol can also react with traditional anti-wear agents such as sulfur-phosphorus-zinc salts, leading to a decrease in anti-wear performance.

[0003] Chinese invention patent application CN115305134 A discloses a low-alkalinity marine cylinder oil composition, preparation method, and application, comprising the following components: 6-20 parts of detergent, derived from at least one of sulfonate, sulfurized alkylphenol salt, or salicylate; 0.5-5 parts of dispersant, derived from high molecular weight ashless dispersant, succinimide dispersant, or boronized ashless dispersant; 0-5 parts of antioxidant, derived from a mixture of sulfur-phosphorus zinc salt and amine antioxidant; and 70-90 parts of base oil. The composition has a calcium content of not less than 10,000 ppm and an alkalinity of not less than 30 mg KOH / g and not more than 50 mg KOH / g, as well as the technical solution for its preparation method and application. This invention addresses the problem in existing technologies where low-alkalinity marine cylinder oils cannot meet the detergency requirements for use with low-sulfur fuels with a sulfur content not exceeding 0.5% m / m. It satisfies the lubrication requirements of marine low-speed two-stroke diesel engines using fuels with a sulfur content below 0.5%, exhibiting superior high-temperature detergency, anti-wear properties, and oxidation stability, making it suitable for cylinder lubrication. However, this cylinder oil composition is designed for traditional marine residual fuel oils and is not applicable to methanol fuel.

[0004] Chinese invention patent CN103509634B discloses a lubricating oil composition for engines using methanol or methanol gasoline as fuel. The lubricating oil composition includes at least one metal detergent, an ashless dispersant, an antioxidant, anti-corrosion, and anti-wear agent, a viscosity index improver, a pour point depressant, a rust inhibitor, an anti-foaming agent, and a base oil. The formulated lubricating oil composition effectively solves the corrosion and wear problems of methanol gasoline engines, exhibiting excellent acid neutralization and alkali retention properties, good anti-wear, detergent-dispersant, and antioxidant properties, and meeting the lubrication requirements of methanol gasoline engines. It is suitable for the lubrication requirements of methanol gasoline (M5-M100) engines with any blend ratio. However, the anti-wear and anti-corrosion properties of this composition need further improvement.

[0005] Therefore, there is an urgent need to provide a methanol-fueled marine cylinder oil composition with higher anti-wear and anti-corrosion properties. Summary of the Invention

[0006] This invention improves the anti-wear and anti-corrosion properties of oil products when contaminated by methanol and formic acid by optimizing the detergent and dispersant scheme and introducing a combination of technologies such as metal deactivators. It forms a cylinder oil composition suitable for methanol fuel marine engines that can meet the performance requirements of marine two-stroke engines using methanol fuel.

[0007] The first aspect of the present invention is to provide a cylinder oil composition suitable for methanol fuel marine use, comprising, by weight percentage: 5.0%-20% detergent, 1.0%-8.0% ashless dispersant, 0.5%-1.5% composite antioxidant, 0.5%-3% anti-wear agent, 0.01%-1% metal deactivator, with the balance being base oil;

[0008] The detergent is composed of high-alkalinity synthetic calcium sulfonate, low-alkalinity synthetic calcium sulfonate, high-alkalinity borosulfonate, and high-alkalinity alkylphenol calcium sulfide. The total alkalinity of the high-alkalinity synthetic calcium sulfonate is not less than 295 mg KOH / g, the total alkalinity of the low-alkalinity synthetic calcium sulfonate is 20-30 mg KOH / g, the total alkalinity of the high-alkalinity alkylphenol calcium sulfide is not less than 250 mg KOH / g, and the total alkalinity of the high-alkalinity borosulfonate is not less than 200 mg KOH / g.

[0009] Preferably, the mass ratio of the high-alkalinity synthetic calcium sulfonate, the low-alkalinity synthetic calcium sulfonate, the high-alkalinity borate calcium sulfonate, and the high-alkalinity alkylphenol calcium sulfide is 4.5-6:4-5:4-6:4.5-6.

[0010] Preferably, the ashless dispersant is polyisobutylene succinimide.

[0011] More preferably, the polyisobutylene succinimide is a mono- or bis- or polyisobutylene succinimide, or a polyisobutylene diimide, or a combination of the three in any proportion.

[0012] Preferably, the composite antioxidant is composed of amine antioxidant and phenolic antioxidant, wherein, by mass percentage, the amine antioxidant accounts for 60%-80% of the composite antioxidant, and the remainder is phenolic antioxidant.

[0013] More preferably, the amine antioxidant is selected from at least one of butyloctyl diphenylamine and dioctyl diphenylamine.

[0014] More preferably, the phenolic antioxidant is selected from at least one of 2,6-di-tert-butyl-p-cresol and high molecular weight phenolic ester compounds.

[0015] Preferably, the anti-wear agent is selected from at least one of primary alcohol-based zinc thiophosphate with a carbon chain length of C12-C18 and secondary alcohol-based zinc thiophosphate with a carbon chain length of C12-C18.

[0016] Preferably, the metal deactivator is selected from at least one of benzotriazole derivatives and thiadiazole derivatives.

[0017] Preferably, the base oil is a mixture of Group I base oil PCL 400SN and bright base oil PCLH 150BS produced by solvent refining process, and the kinematic viscosity of this base oil at 100°C is 9-33 mm. 2 / s.

[0018] A second aspect of the present invention is to provide a method for preparing the above-mentioned methanol-fueled marine cylinder oil composition, comprising the following steps:

[0019] (1) Add the base oil to the blending tank and heat it to 60-70℃ so that the kinematic viscosity of the base oil mixture reaches 13-16 mm at 100℃. 2 / s;

[0020] (2) Add the detergent, ashless dispersant, compound antioxidant, anti-wear agent and metal deactivator to the above mixing tank and stir evenly at 60-70℃ to obtain the product.

[0021] Compared with the prior art, the present invention has the following beneficial effects: by optimizing the detergent and dispersant scheme and introducing a combination of technologies such as metal deactivators, the anti-wear and anti-corrosion properties of the oil are improved when it is contaminated by methanol and formic acid, forming a cylinder oil composition suitable for methanol fuel marine engines, which can meet the performance requirements of marine two-stroke engines using methanol fuel. Detailed Implementation

[0022] Example 1:

[0023] With the lubricating oil accounting for 100% by mass, the component composition of Examples 1-6 and Comparative Examples 1-3 is shown in Table 1.

[0024] Table 1: Component composition of Examples 1-6 and Comparative Examples 1-3

[0025]

[0026]

[0027] Test example:

[0028] The antioxidant properties, anti-wear properties, load-bearing capacity, and corrosion resistance of the methanol-fueled marine cylinder oil compositions of the above embodiments and comparative examples were evaluated, and the results are shown in Table 2. In the experiment, a certain amount of formic acid and methanol were added to the methanol-fueled marine cylinder oil compositions to simulate the pollution caused by incomplete combustion of methanol fuel.

[0029] The thermal oxidation stability of the samples was evaluated using pressure differential scanning calorimetry (PDSC). The test temperature was 210℃, the pressure was 690kPa, and the medium was air. The PDSC test examines the oxidation resistance of oil products under high temperature, high pressure, and air contact conditions, and the result is expressed as the oxidation induction period of the test sample. The longer the oxidation induction period, the better the oxidation resistance.

[0030] Copper strip corrosion refers to the chemical reaction between copper strips and corrosive media, resulting in damage and color changes on the surface of the copper strips. It is used to determine the corrosion resistance of oil products; the higher the value, the worse the corrosion resistance of the oil product.

[0031] The CBT corrosion test is used to evaluate the corrosion resistance of oil products. The higher the content of metal elements, the worse the corrosion resistance of the oil product.

[0032] The SRV (Strain Radius) friction coefficient and the diameter of the four-ball wear scar characterize the anti-friction performance of the oil; the lower the value, the better the anti-friction performance. The maximum non-seize load indicates the load-bearing capacity of the oil, recording the system load when the oil causes sintering of the test metal balls and the maximum system load when no seizing occurs; the higher the value, the better the load-bearing capacity of the oil.

[0033] Table 2: Simulation evaluation test results of Examples 1-6 and Comparative Examples 1-3

[0034]

[0035] Through the examples and comparative examples, it can be seen that by introducing high-alkalinity calcium borate sulfonate into the detergent and using it in combination with other antioxidants and anti-wear agents, the antioxidant properties, anti-wear properties, and load-carrying capacity of the oil are significantly improved; at the same time, the introduction of metal deactivators significantly improves the corrosion resistance of the oil. The overall performance of the oils in each example is better than that in each comparative example. This invention, through the introduction of two novel single agents and their scientific compounding with other single agents, improves the anti-wear and anti-corrosion properties of oils when contaminated by methanol and formic acid, meeting the performance requirements of marine two-stroke engines using methanol fuel.

[0036] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A marine cylinder oil composition suitable for use with methanol fuel, consisting of the following components, in mass percent: detergent 5.0%-20%, ashless dispersant 1.0%-8.0%, composite antioxidant 0.5%-1.5%, anti-wear agent 0.5-3%, metal deactivator 0.01-1%, and the rest is base oil; The detergent is composed of high-alkali-value synthetic calcium sulfonate, low-alkali-value synthetic calcium sulfonate, high-alkali-value boronized calcium sulfonate, and high-alkali-value sulfided calcium alkylphenate, wherein the alkali value of the high-alkali-value synthetic calcium sulfonate is not less than 295, the alkali value of the low-alkali-value synthetic calcium sulfonate is 20-30, the alkali value of the high-alkali-value sulfided calcium alkylphenate is not less than 250, and the alkali value of the high-alkali-value boronized calcium sulfonate is not less than 200.

2. The marine cylinder oil composition suitable for methanol fuel according to claim 1, characterized in that, The mass ratio of the high-alkali-value synthetic calcium sulfonate, the low-alkali-value synthetic calcium sulfonate, the high-alkali-value boronized calcium sulfonate, and the high-alkali-value sulfided calcium alkylphenate is 4.5-6:4-5:4-6:4.5-6.

3. The marine cylinder oil composition suitable for methanol fuel according to claim 1, characterized by, The ashless dispersant is polyisobutylene succinimide.

4. The marine cylinder oil composition suitable for methanol fuel according to claim 3, characterized in that, The polyisobutylene succinimide is single-hung polyisobutylene succinimide, double-hung polyisobutylene succinimide, or multi-hung polyisobutylene succinimide, or a composition composed of the three in any ratio.

5. The marine cylinder oil composition suitable for methanol fuel according to claim 1, characterized by, The composite antioxidant is composed of amine-type antioxidant and phenolic antioxidant, wherein the mass ratio of the amine-type antioxidant in the composite antioxidant is 60%-80%, and the rest is phenolic antioxidant.

6. The marine cylinder oil composition suitable for methanol fuel according to claim 5, characterized in that, The amine-type antioxidant is at least one selected from butyloctyl diphenylamine and dioctyl diphenylamine.

7. The marine cylinder oil composition suitable for methanol fuel according to claim 5, characterized in that, The phenolic antioxidant is at least one selected from 2,6-di-tert-butyl-p-cresol and high-molecular phenolic ester compound.

8. The marine cylinder oil composition suitable for methanol fuel according to claim 1, characterized by, The anti-wear agent is at least one selected from primary alcohol group zinc thiophosphate with a carbon chain length of C12-C18 and secondary alcohol group zinc thiophosphate with a carbon chain length of C12-C18.

9. The marine cylinder oil composition suitable for methanol fuel according to claim 1, characterized by, The metal deactivator is at least one selected from benzene triazole derivative and thiadiazole derivative.

10. The marine cylinder oil composition suitable for methanol fuel according to claim 1, characterized in that, The base oil is a mixture of a Group I base oil PCL 400SN produced using a solvent refining process and a bright stock PCLH 150BS, having a kinematic viscosity at 100°C of 9-33 mm 2 / s.

11. A preparation method of the marine cylinder oil composition suitable for methanol fuel, according to any one of claims 1-10, comprising the following steps: (1) Add base oils to a blending tank and warm to 60-70°C such that the base oil mixture has a kinematic viscosity at 100°C of 13-16 mm 2 / s; (2) adding the detergent, ashless dispersant, composite antioxidant, anti-wear agent, and metal deactivator into a blending tank, and stirring uniformly at 60-70°C to obtain the marine cylinder oil composition.

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