CN116376622A

CN116376622A - Coal-based engine oil and application thereof

Info

Publication number: CN116376622A
Application number: CN202310362557.9A
Authority: CN
Inventors: 余昊轩; 张春化; 沈永斌; 李阳阳; 梁雪美; 彭朝林; 安良成; 燕艺楠; 李艳
Original assignee: National Energy Group Ningxia Coal Industry Co Ltd
Current assignee: National Energy Group Ningxia Coal Industry Co Ltd
Priority date: 2023-04-06
Filing date: 2023-04-06
Publication date: 2023-07-04

Abstract

The invention provides coal-based engine oil and application thereof. The coal-based engine oil comprises coal-based lubricating oil base oil, polyol ester and additives; the coal-based lubricating oil base oil is prepared by cutting Fischer-Tropsch synthesis products and comprises first base oil with a distillation range of 367.0-505.0 ℃ and/or second base oil with a distillation range of 406.5-529.5 ℃. Compared with the engine oil taking the traditional petroleum-based base oil as the main component, the coal-based engine oil provided by the application can take coal resources as sources, and can reduce the petroleum demand. In addition, the high viscosity and excellent low temperature performance, oxidation resistance, antifriction and antiwear performance and other comprehensive performances are provided, thereby prolonging the service life of the engine and improving the working efficiency of the engine.

Description

Coal-based engine oil and application thereof

Technical Field

The invention relates to the technical field of lubricating oil preparation, in particular to coal-based engine oil and application thereof.

Background

In the working process of the engine, in order to exert the effects of antifriction and antiwear, cooling, sealing, cleaning and the like of the engine oil, thereby prolonging the service life of the engine and improving the working efficiency of the engine, the engine oil with good viscosity-temperature property, oxidation resistance, extreme pressure and antiwear property, low-temperature fluidity and the like is required to be adopted. However, the traditional engine oil is petroleum-based base oil and is derived from petroleum, and the current situation of the energy structure of 'more coal, less oil and less gas deficiency' in China is faced, so that searching for a substitute for petroleum becomes one of the urgent tasks in the petrochemical field.

Current production technology has enabled coal-based lube base oils to be produced by coal gasification to synthesis gas (CO and H ₂ ) Purifying and desulfurizing the synthesis gas to regulate H ₂ After the ratio of CO to the catalyst, the catalyst is sent into a Fischer-Tropsch synthesis slurry bed reactor to be converted into liquid under the action of the catalyst, and then hydrofined to obtain coal-basedFischer-Tropsch GTL base oil. The coal-based lubricating oil base oil prepared by the process has excellent low-temperature performance and high-temperature tolerance, the viscosity index of the coal-based lubricating oil base oil can reach more than 130, and each physical and chemical index is close to PAO synthetic oil, so that the coal-based lubricating oil base oil has good substitution for the traditional petroleum-based total synthetic base oil.

However, all properties of the currently prepared coal-based lubricating oil base oil still have room for improvement, and the same level of the fully synthesized gasoline engine oil is still difficult to reach, and the specification requirements of API SN/ILSAC GF-5 cannot be met.

Therefore, research and development of a coal-based engine oil with excellent viscosity-temperature characteristics, oxidation resistance, antifriction and antiwear properties and the like have important significance in searching for a substitute of the traditional petroleum base oil.

Disclosure of Invention

The invention mainly aims to provide coal-based engine oil and application thereof, so as to solve the problems that the traditional petroleum-based base oil in the prior art has large petroleum demand and the existing petroleum resources are difficult to meet the petroleum demand, and particularly the existing coal-based lubricating oil is difficult to simultaneously have excellent viscosity-temperature characteristics, oxidation resistance and antifriction and antiwear properties.

In order to achieve the above object, in one aspect, the present invention provides a coal-based engine oil comprising a coal-based lubricating oil base oil, a polyol ester, and an additive; the coal-based lubricating oil base oil is prepared by cutting Fischer-Tropsch synthesis products and comprises first base oil with a distillation range of 367.0-505.0 ℃ and/or second base oil with a distillation range of 406.5-529.5 ℃.

Further, the weight percentage of the coal-based lubricating oil base oil to the coal-based engine oil is more than or equal to 65wt%.

Further, the first base oil contains a hydrocarbon having 21 to 33 carbon atoms, preferably a hydrocarbon having 22 to 30 carbon atoms; the second base oil contains a hydrocarbon having 22 to 43 carbon atoms, preferably a hydrocarbon having 29 to 40 carbon atoms; preferably, when the coal-based lubricating oil base oil is a mixture of the first base oil and the second base oil, the weight ratio of the first base oil to the second base oil is (10-20): (50-85).

Further, the coal-based engine oil comprises 69.2 to 85.3 parts by weight of the coal-based lubricating oil base oil, 3 to 8 parts by weight of the polyol ester and 11.7 to 22.8 parts by weight of the additive.

Further, the additive comprises one or more of a viscosity index improver, a pour point depressant, a detergent, a friction improver, an antiwear agent, a dispersant, an antioxidant, a defoamer and an antirust agent; preferably, the coal-based engine oil further comprises, by weight, 7 to 12 parts of a viscosity index improver, 0.2 to 0.5 part of a pour point depressant, 1.5 to 2 parts of a detergent, 0.05 to 0.1 part of a friction modifier, 0.5 to 1.0 part of an antiwear agent, 2.0 to 5.0 parts of a dispersant, 0.4 to 1 part of an antioxidant, 0.001 to 0.005 part of a defoamer, and 0.05 to 0.1 part of an antirust agent.

Further, the viscosity index improver is a hydrogenated styrene diene copolymer; preferably, the pour point depressant is polymethacrylate; preferably the detergent is an alkyl salicylate and/or a synthetic sulfonate; preferred friction modifiers are MoDTC and/or Molyvan855; preferably the antiwear agent is ZDDP; preferably the dispersant is a boronated polyisobutylene succinimide; preferably, the antioxidant is octyl butyl alkylated diphenylamine and/or 2, 6-di-tert-butyl xylenol; preferably, the defoamer is methyl silicone oil; the rust inhibitor is benzotriazole.

Further, when the detergent is a mixture of alkyl salicylate and synthetic sulfonate, the weight ratio of alkyl salicylate to synthetic sulfonate is (0.5-1.0): 1.0-2.0; preferably the detergent is a mixture of T109 and T106D.

Further, when the antioxidant is a mixture of octyl butyl alkylated diphenylamine and 2, 6-di-t-butylxylenol, the weight ratio of octyl butyl alkylated diphenylamine to 2, 6-di-t-butylxylenol is (0.2-0.5).

Further, the coal-based engine oil comprises, by weight, 10 to 20 parts of a first base oil, 50 to 85 parts of a second base oil, 3 to 8 parts of a polyol ester, 7 to 12 parts of a hydrogenated styrene diene copolymer, 0.2 to 0.5 part of a polymethacrylate, 0.5 to 1.0 part of T109, 1.0 to 2.0 parts of T106D, 0.05 to 0.1 part of MoDTC, 0.5 to 1.0 part of ZDDP, 2.0 to 5.0 parts of a boronated polyisobutylene succinimide, 0.2 to 0.5 part of octyl butyl alkylated diphenylamine, 0.2 to 0.5 part of 2, 6-di-tert-butyl xylenol, 0.001 to 0.005 part of methyl silicone oil, and 0.05 to 0.1 part of benzotriazole.

In order to achieve the above object, another aspect of the present invention also provides an application of the above coal-based engine oil provided in the application in the field of automobile, mechanical or industrial production.

Compared with the traditional engine oil taking petroleum-based base oil as a main component, the coal-based engine oil provided by the application takes coal resources as a source, and can reduce petroleum demand. Moreover, the inventors have found through extensive research that limiting the composition of the coal-based lubricant base oil to products within a specific distillation range (i.e., the first base oil and the second base oil) during the cleavage of the Fischer-Tropsch synthesis product provides considerable advantages over existing coal-based lubricant base oils. The first base oil and the second base oil respectively have higher viscosity index and lower pour point, so that the coal-based engine oil has more excellent viscosity-temperature characteristics, has high viscosity and simultaneously has excellent comprehensive properties such as low-temperature performance, oxidation resistance, antifriction and antiwear performance, so that the service life of the engine can be prolonged, and the working efficiency of the engine can be improved.

The ester group in the polyol ester has strong adsorption effect with the friction surface, and the long carbon chain covers the friction surface to form an interfacial oil film, so that the antifriction and antiwear performance of the coal-based engine oil can be improved; meanwhile, the compatibility of the base oil of the coal-based lubricating oil and the additive can be improved by adding the polyol ester, so that the comprehensive properties of the viscosity-temperature characteristic, the oxidation resistance, the antifriction and antiwear performance and the like of the coal-based engine oil can be brought into play.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 shows a graph of the carbon number distribution of a first base oil employed in the examples herein;

fig. 2 shows a carbon number distribution diagram of the second base oil employed in the examples in the present application.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present invention will be described in detail with reference to examples.

As described in the background art, the existing conventional petroleum-based base oil has a large petroleum demand, which results in the problem that the existing petroleum resources are difficult to meet the petroleum demand, and especially the existing coal-based lubricating oil has the problem that it is difficult to simultaneously have excellent viscosity-temperature characteristics, oxidation resistance and antifriction and antiwear properties. In order to solve the technical problems, the application provides a coal-based engine oil, which comprises coal-based lubricating oil base oil, polyol ester and additives; the coal-based lubricating oil base oil is prepared by cutting Fischer-Tropsch synthesis products and comprises first base oil with a distillation range of 367.0-505.0 ℃ and/or second base oil with a distillation range of 406.5-529.5 ℃.

Compared with the engine oil taking the traditional petroleum-based base oil as the main component, the coal-based engine oil provided by the application takes coal resources as sources, and can reduce the petroleum demand. Moreover, the inventors have found through extensive research that limiting the composition of the coal-based lubricant base oil to products within a specific distillation range (i.e., the first base oil and the second base oil) during the cleavage of the Fischer-Tropsch synthesis product provides considerable advantages over existing coal-based lubricant base oils. The first base oil and the second base oil respectively have higher viscosity index and lower pour point, so that the coal-based engine oil has more excellent viscosity-temperature characteristics, has high viscosity and simultaneously has excellent comprehensive properties such as low-temperature performance, oxidation resistance, antifriction and antiwear performance, so that the service life of the engine can be prolonged, and the working efficiency of the engine can be improved.

In a preferred embodiment, the coal-based lubricant base oil comprises greater than or equal to 65 wt.% of the coal-based engine oil. The weight percentage of the base oil of the coal-based lubricating oil to the coal-based engine oil comprises but is not limited to the range, and the base oil is limited to the range, so that the use proportion of the traditional base oil is reduced, the cost of the engine lubricating oil is reduced, and the comprehensive properties such as viscosity-temperature characteristic, oxidation resistance, antifriction and antiwear performance and the like of the coal-based engine lubricating oil are improved.

In a preferred embodiment, the first base oil contains a hydrocarbon having 21 to 33 carbon atoms; the second base oil contains hydrocarbons having 22 to 43 carbon atoms. Limiting the constituent components of the first base oil and the second base oil within the above ranges is advantageous in improving the viscosity index thereof while reducing the pour point, as compared to other hydrocarbons of carbon number, thereby being advantageous in improving the low temperature performance of the coal-based engine oil.

In order to further increase the viscosity index of the coal-based lubricating oil base oil and to further reduce the pour point, it is preferable that the first base oil contains a hydrocarbon having 22 to 30 carbon atoms and the second base oil contains a hydrocarbon having 29 to 40 carbon atoms.

In a preferred embodiment, when the coal-based lubricating oil base oil is a mixture of a first base oil and a second base oil, the weight ratio of the first base oil to the second base oil is (10-20): (50-85). The weight ratio of the first base oil to the second base oil includes, but is not limited to, the above ranges, and limiting them to the above ranges facilitates further increasing the viscosity index of the coal-based lubricant base oil while reducing the pour point, thereby facilitating further increasing the low temperature performance of the coal-based engine oil.

In a preferred embodiment, the coal-based engine oil comprises 69.2 to 85.3 parts by weight of the coal-based lubricant base oil, 3 to 8 parts by weight of the polyol ester, and 11.7 to 22.8 parts by weight of the additive. Compared with other dosage ranges, the dosage of the coal-based lubricating oil base oil, the polyol ester and the additive in the coal-based engine oil is limited in the range, so that the compatibility of the coal-based lubricating oil base oil and the additive is improved, the synergistic effect of the coal-based lubricating oil base oil and the additive is better exerted, and the coal-based engine oil has better performance in the aspects of improving the comprehensive performances of the viscosity-temperature characteristic, the oxidation resistance, the antifriction and antiwear performance and the like.

The viscosity index improver is usually an oil-soluble chain high polymer, is coiled at a low Wen Shifen sub-chain and is expanded at a high Wen Shifen sub-chain, and the viscosity index improver can be introduced into an additive formula to reduce the low-temperature viscosity of the coal-based lubricating oil base oil and improve the high-temperature viscosity of the coal-based lubricating oil base oil, so that the applicable temperature range of the coal-based engine oil can be widened. The pour point depressant can lower the solidifying point of the base oil of the coal-based lubricating oil, thereby being beneficial to improving the low-temperature fluidity of the coal-based engine oil and improving the low-temperature performance of the coal-based engine oil. The detergent has the function of inhibiting and removing engine sediment, and the introduction of the detergent can remarkably improve the starting performance of the engine and reduce the emission to a certain extent. The friction modifier can reduce the friction coefficient between surfaces, and the introduction of the friction modifier is beneficial to reducing energy loss and improving the economy of the coal-based engine oil. The introduction of the antiwear agent can reduce friction, abrasion and sintering of mechanical parts in the engine, so that the engine is lubricated, thereby being beneficial to improving the working efficiency of the engine and prolonging the service life of the engine. The introduction of the dispersing agent can disperse dirt in the coal-based engine oil, prevent the dirt from forming sediment, be beneficial to the lubrication of the engine and inhibit the influence of the sediment on the normal operation of the engine. The introduction of the antioxidant can inhibit the oxidative deterioration of the coal-based engine oil, thereby being beneficial to prolonging the service life of the coal-based engine oil. The introduction of the defoamer is beneficial to inhibiting the foaming of the coal-based engine oil in the production process, thereby being beneficial to inhibiting the influence of the foaming on the performance of the coal-based engine oil. The introduction of the rust inhibitor can inhibit the corrosion of external salt to the coal-based engine oil, thereby being beneficial to inhibiting the discoloration and the rust, and further being beneficial to prolonging the service life of the engine.

In a preferred embodiment, the additive comprises one or more of the group consisting of viscosity index improvers, pour point depressants, detergents, friction modifiers, antiwear agents, dispersants, antioxidants, antifoam agents, and rust inhibitors. The additive with corresponding functions is singly or compositely introduced into the engine oil to be beneficial to playing corresponding functions, so that the comprehensive performance of the coal-based engine oil is improved.

In order to further improve various properties of the coal-based engine oil, thereby further extending the service life of the engine, preferably, the coal-based engine oil further comprises, in parts by weight, 7 to 12 parts of a viscosity index improver, 0.2 to 0.5 part of a pour point depressant, 1.5 to 2 parts of a detergent, 0.05 to 0.1 part of a friction improver, 0.5 to 1.0 part of an antiwear agent, 2.0 to 5.0 parts of a dispersant, 0.4 to 1 part of an antioxidant, 0.001 to 0.005 part of an antifoaming agent, and 0.05 to 0.1 part of an antirust agent.

The viscosity index improver and the pour point depressant may be of the types commonly used in the art, respectively. In a preferred embodiment, the viscosity index improver is a hydrogenated styrene diene copolymer. Pour point depressants of the present application may be of the type commonly used in the art. In a preferred embodiment, the pour point depressant is a polymethacrylate.

In a preferred embodiment, the detergent is an alkyl salicylate and/or a synthetic sulfonate. The use of the above-described preferred types of detergents is advantageous in further suppressing and scavenging engine deposits, further improving engine starting performance, and also further reducing emissions, as compared to other types.

In a preferred embodiment, friction modifiers include, but are not limited to, moDTC and/or Molyvan855. The use of the above-described preferred types of friction modifiers is advantageous in further reducing the coefficient of friction between surfaces, and thus in further reducing energy loss, and in further improving the economy of coal-based engine oils, as compared to other types.

In a preferred embodiment, the antiwear agent is ZDDP. The use of the above-described preferred types of antiwear agents is advantageous in further suppressing oxidative deterioration of the coal-based engine oil, as compared with other types, and thus in further extending the service life of the coal-based engine oil.

In a preferred embodiment, the dispersant is a boronated polyisobutylene succinimide. The use of the above-described preferred types of dispersants is advantageous in further suppressing the formation of deposits from dirt, and thus in further suppressing the influence of the deposits on the normal operation of the engine, as compared with other types.

In a preferred embodiment, the antioxidant is octyl butyl alkylated diphenylamine and/or 2, 6-di-t-butylxylenol. The use of the above-described preferred types of antioxidants is advantageous in further suppressing oxidative deterioration of the coal-based engine oil, as compared with other types, and thus is advantageous in further extending the service life of the coal-based engine oil.

The defoamer and the rust inhibitor in the present application may be of the types commonly used in the art, respectively. In a preferred embodiment, the defoamer is a methyl silicone oil. In a preferred embodiment, the rust inhibitor is benzotriazole.

In a preferred embodiment, when the detergent is a mixture of alkyl salicylate and synthetic sulfonate, the weight ratio of alkyl salicylate to synthetic sulfonate is from (0.5 to 1.0): from (1.0 to 2.0). The weight ratio of alkyl salicylate to synthetic sulfonate includes, but is not limited to, the above ranges, and limiting it to the above ranges facilitates further inhibition and removal of engine deposits, thereby further improving engine starting performance while still further reducing emissions.

To further inhibit and remove engine deposits, thereby further improving engine starting performance, while still further reducing emissions, the detergent is preferably a mixture of T109 and T106D.

In a preferred embodiment, when the antioxidant is a mixture of octyl butyl alkylated diphenylamine and 2, 6-di-t-butylxylenol, the weight ratio of octyl butyl alkylated diphenylamine to 2, 6-di-t-butylxylenol is from (0.2 to 0.5): from (0.2 to 0.5). The weight ratio of the octyl butyl alkylated diphenylamine to the 2, 6-di-tert-butyl xylenes includes, but is not limited to, the above ranges, which are advantageous for further inhibiting the oxidative deterioration of the coal-based engine oil, thereby facilitating further extension of the service life of the coal-based engine oil.

In a preferred embodiment, the coal-based engine oil comprises, by weight, 10 to 20 parts of a first base oil, 50 to 85 parts of a second base oil, 3 to 8 parts of a polyol ester, 7 to 12 parts of a hydrogenated styrene diene copolymer, 0.2 to 0.5 parts of a polymethacrylate, 0.5 to 1.0 part of T109, 1.0 to 2.0 parts of T106D, 0.05 to 0.1 part of a MoDTC, 0.5 to 1.0 part of ZDDP, 2.0 to 5.0 parts of a boronated polyisobutylene succinimide, 0.2 to 0.5 parts of an octylbutyl alkylated diphenylamine, 0.2 to 0.5 parts of 2, 6-di-T-butylxylenol, 0.001 to 0.005 parts of a methyl silicone oil, and 0.05 to 0.1 part of benzotriazole. Compared with other components and the dosage thereof, the types and the dosage of each component in the coal-based engine oil are limited in the range, which is beneficial to improving the comprehensive properties of the coal-based engine oil such as viscosity-temperature characteristic, oxidation resistance, antifriction and antiwear property and the like.

The second aspect of the application also provides application of the coal-based engine oil in the field of automobile, mechanical or industrial production. The coal-based engine oil provided by the application has excellent viscosity-temperature characteristics, oxidation resistance and antifriction and antiwear properties, and is particularly suitable for a gasoline engine for a vehicle.

The present application is described in further detail below in conjunction with specific embodiments, which should not be construed as limiting the scope of the claims.

Example 1

The kinds and amounts of the components of the coal-based engine oil are shown in Table 1. In Table 1, a coal-based lubricating oil base oil was prepared by cutting a Fischer-Tropsch synthesis product and comprises a first base oil having a boiling range of 367.0 to 505.0 ℃ and a second base oil having a boiling range of 406.5 to 529.5 ℃, wherein the first base oil contains hydrocarbons having 21 to 33 carbon atoms (the carbon number distribution diagram of which is shown in FIG. 1) and the second base oil contains hydrocarbons having 22 to 43 carbon atoms (the carbon number distribution diagram of which is shown in FIG. 2).

A process for blending coal-based engine oil, comprising:

mixing the first base oil, the second base oil and the polyol ester Priolube 3970 to obtain coal-based lubricating oil base oil; heating the coal-based lubricating oil base oil to 50 ℃, adding hydrogenated styrene diene copolymer and Polymethacrylate (PMA), adding antioxidant octyl butyl alkylated diphenylamine and 2, 6-di-tert-butyl xylenol, adding boronated polyisobutene succinimide, adding friction modifier MoDTC, heating the system to 70 ℃, dissolving, cooling to 50 ℃, adding detergents T109 and T106D, and sequentially adding antiwear agent ZDDP, defoamer methyl silicone oil and antirust agent benzotriazole; the components are uniformly mixed, and the kinematic viscosity at 100 ℃ and the low-temperature dynamic viscosity CCS are detected in the blending process.

Examples 2 to 5

The difference from example 1 is that: the amounts of the components in the coal-based engine oil are different from those in example 1 and are shown in Table 1.

The blending process of the coal-based engine oil in examples 2 to 5 is the same as that of example 1.

TABLE 1

Examples 6 to 8

The kinds and amounts of the components of the coal-based engine oil are shown in Table 2. In Table 2, a coal-based lube base stock is prepared by cutting Fischer-Tropsch products and comprises a first base stock having a boiling range of 367.0 to 505.0 ℃ and a second base stock having a boiling range of 406.5 to 529.5 ℃, wherein the first base stock contains hydrocarbons having 21 to 33 carbon atoms (the carbon number distribution diagram of which is shown in FIG. 1) and the second base stock contains hydrocarbons having 22 to 43 carbon atoms (the carbon number distribution diagram of which is shown in FIG. 2).

The blending process of the coal-based engine oil in examples 6 to 8 is the same as that of example 1.

TABLE 2

Example 9

The difference from example 1 is that: the weight ratio of the first base oil to the second base oil was 10:85, and the parts by weight of the coal-based lubricating oil base oil was the same as in example 1 (73.73 parts). The remaining components in the coal-based engine oil were the same as in example 1, respectively. The blending process of the coal-based engine oil is the same as in example 1.

Example 10

The difference from example 1 is that: the weight ratio of the first base oil to the second base oil was 20:50, and the parts by weight of the coal-based lubricating oil base oil was the same as in example 1 (73.73 parts). The remaining components in the coal-based engine oil were the same as in example 1, respectively. The blending process of the coal-based engine oil is the same as in example 1.

Comparative example 1

The petroleum base oil comprises, by weight, 56 parts of a group II base oil, 18 parts of a PAO base oil, 8 parts of a synthetic ester base oil, 2.5 parts of a metal detergent, 3.5 parts of an ashless dispersant, 2.25 parts of an antioxidant antiwear agent, 0.8 part of a friction reducer, 8.5 parts of a finger sticking agent, 0.45 parts of a pour point depressant and 0.001 part of an antifoaming agent.

Comparative example 2

The coal-based lubricating oil comprises, by weight, 50 parts of 1# coal-based base oil, 35 parts of 2# coal-based base oil, 8 parts of a gasoline engine oil complexing agent, 0.5 part of a pour point depressant PMA, 6.48 parts of a viscosity index improver hydrogenated styrene and 0.02 part of a composite anti-foaming agent polyacrylate.

Comparative example 3

The difference from example 1 is that: no polyol ester was added.

Various performance tests were performed on the coal-based engine oils in all of the above examples and comparative examples of the present application, and the test items and test results are shown in tables 3 and 4.

TABLE 3 Table 3

TABLE 4 Table 4

From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

as shown by test results, the coal-based engine oil prepared by blending in the embodiment provided by the application has good low-temperature performance, viscosity-temperature characteristic, oxidation resistance, antifriction and antiwear performance and the like, meets the requirements of API SN/ILSAC GF-5 specification, and is therefore suitable for being used as high-end engine lubricating oil of a gasoline engine for a vehicle.

As can be seen from comparing example 1 with comparative examples 1 and 2, limiting the composition of the coal-based lubricant base oil to products within a specific distillation range (i.e., the first base oil and the second base oil) during the cleavage of the fischer-tropsch synthesis product provides considerable advantages over the existing coal-based lubricant base oils. The first base oil and the second base oil respectively have higher viscosity index and lower pour point, so that the coal-based engine oil has more excellent viscosity-temperature characteristics, has high viscosity and simultaneously has excellent comprehensive properties such as low-temperature performance, oxidation resistance, antifriction and antiwear performance, so that the service life of the engine can be prolonged, and the working efficiency of the engine can be improved.

Comparative example 1 and comparative example 3, the addition of polyol esters can improve the antifriction and antiwear properties of coal-based engine oils; meanwhile, the compatibility of the base oil and the additive of the coal-based lubricating oil can be improved, so that the comprehensive properties of the coal-based engine oil, such as viscosity-temperature characteristic, oxidation resistance, antifriction and antiwear performance, can be brought into play.

Comparing examples 1 to 5 and examples 6 to 8, it is known that, compared with other dosage ranges, limiting the dosage of the coal-based lubricating oil base oil, the polyol ester and the additive in the preferred range of the application is more beneficial to improving the compatibility of the coal-based lubricating oil base oil and the additive, and better performing the synergistic effect of the three, and better performing the comprehensive performance of improving the viscosity-temperature characteristic, the oxidation resistance, the antifriction and antiwear performance and the like of the coal-based engine oil; in addition, compared with other components and the dosage thereof, the types and the dosage of the additives in the coal-based engine oil are limited within the preferred ranges of the application, so that the combination properties such as viscosity-temperature characteristics, oxidation resistance, antifriction and antiwear performance and the like of the coal-based engine oil are improved.

As can be seen from comparing examples 1, 9 and 10, compared with other dosage ranges, limiting the dosage of the coal-based lubricating oil base oil, the polyol ester and the additive in the coal-based engine oil within the preferred ranges of the present application is more favorable for improving the compatibility of the coal-based lubricating oil base oil and the additive, and better performing the synergistic effect of the three, and has better performance in improving the comprehensive properties of the coal-based engine oil, such as viscosity-temperature characteristic, oxidation resistance, antifriction and antiwear performance.

It should be noted that the terms "first," "second," and the like in the description and in the claims of the present application are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those described herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A coal-based engine oil, characterized in that the coal-based engine oil comprises a coal-based lubricating oil base oil, a polyol ester, and an additive; the coal-based lubricating oil base oil is prepared by cutting a Fischer-Tropsch synthesis product and comprises first base oil with a distillation range of 367.0-505.0 ℃ and/or second base oil with a distillation range of 406.5-529.5 ℃.

2. The coal-based engine oil of claim 1, wherein the coal-based lubricant base oil comprises greater than or equal to 65wt% of the coal-based engine oil.

3. The coal-based engine oil according to claim 1 or 2, characterized in that the first base oil contains hydrocarbons having 21 to 33 carbon atoms, preferably hydrocarbons having 22 to 30 carbon atoms; the second base oil contains a hydrocarbon having 22 to 43 carbon atoms, preferably a hydrocarbon having 29 to 40 carbon atoms;

preferably, when the coal-based lubricating oil base oil is a mixture of the first base oil and the second base oil, the weight ratio of the first base oil to the second base oil is (10-20): (50-85).

4. A coal-based engine oil as claimed in any one of claims 1 to 3, characterized in that the coal-based engine oil comprises 69.2 to 85.3 parts by weight of the coal-based lubricating oil base oil, 3 to 8 parts by weight of the polyol ester and 11.7 to 22.8 parts by weight of the additive.

5. The coal-based engine oil of claim 4 wherein the additive comprises one or more of the group consisting of viscosity index improvers, pour point depressants, detergents, friction modifiers, antiwear agents, dispersants, antioxidants, antifoam agents, and rust inhibitors;

preferably, the coal-based engine oil further comprises, by weight, 7 to 12 parts of the viscosity index improver, 0.2 to 0.5 part of the pour point depressant, 1.5 to 2 parts of the detergent, 0.05 to 0.1 part of the friction improver, 0.5 to 1.0 part of the antiwear agent, 2.0 to 5.0 parts of the dispersant, 0.4 to 1 part of the antioxidant, 0.001 to 0.005 part of the antifoaming agent, and 0.05 to 0.1 part of the rust inhibitor.

6. The coal-based engine oil of claim 5 wherein the viscosity index improver is a hydrogenated styrene diene copolymer; preferably, the pour point depressant is polymethacrylate; preferably the detergent is an alkyl salicylate and/or a synthetic sulfonate; preferably the friction modifier is MoDTC and/or Molyvan855; preferably the antiwear agent is ZDDP; preferably the dispersant is a boronated polyisobutylene succinimide; preferably, the antioxidant is octyl butyl alkylated diphenylamine and/or 2, 6-di-tert-butyl xylenol; preferably, the antifoaming agent is methyl silicone oil; preferably, the rust inhibitor is benzotriazole.

7. The coal-based engine oil of claim 6 wherein when the detergent is a mixture of the alkyl salicylate and the synthetic sulfonate, the weight ratio of the alkyl salicylate to the synthetic sulfonate is (0.5-1.0): 1.0-2.0; preferably the detergent is a mixture of T109 and T106D.

8. The coal-based engine oil of claim 6 or 7, wherein when the antioxidant is a mixture of the octylbutylalkylated diphenylamine and the 2, 6-di-t-butylxylenol, the weight ratio of the octylbutylalkylated diphenylamine to the 2, 6-di-t-butylxylenol is (0.2-0.5): 0.2-0.5.

9. The coal-based engine oil of claim 7, comprising, in parts by weight, 10 to 20 parts of the first base oil, 50 to 85 parts of the second base oil, 3 to 8 parts of the polyol ester, 7 to 12 parts of the hydrogenated styrene diene copolymer, 0.2 to 0.5 part of the polymethacrylate, 0.5 to 1.0 part of the T109, 1.0 to 2.0 parts of the T106D, 0.05 to 0.1 part of the MoDTC, 0.5 to 1.0 part of the ZDDP, 2.0 to 5.0 parts of the boronated polyisobutylsuccinimide, 0.2 to 0.5 part of the octylbutylalkylated diphenylamine, 0.2 to 0.5 part of the 2, 6-di-tert-butylxylenol, 0.001 to 0.005 part of the methyl silicone oil, and 0.05 to 0.1 part of the benzotriazole.

10. Use of the coal-based engine oil of any one of claims 1 to 9 in the automotive, mechanical or industrial production field.