Fuel composition containing lubricating additives

Abstract

A fuel composition comprising a fuel and a lubricity additive, wherein the lubricity additive is selected from (1) 1-lauroyl-rac-glycerol, (2) dodecanamide, N-hydroxy-, or (3) 2-ethylhexanoic acid, and the fuel is gasoline.

Description

Technical Field

[0001] The present invention relates to a fuel composition comprising a base fuel and a lubricity additive, more particularly to a fuel composition comprising a base fuel suitable for use in an internal combustion engine and a lubricity additive, a method for improving the lubricity of a fuel composition, and a method for improving the fuel performance of a direct injection engine.

Background Art

[0002] Engine manufacturers are constantly challenged to improve engine efficiency and maximize output, particularly when designing internal combustion engines. Such engines are known to be inefficient because a portion of the burned fuel is not converted into useful energy but is used to overcome frictional forces. More typically, a significant portion of the available energy from the burned fuel is used to overcome the frictional forces generated between the surfaces of the moving engine parts that are in contact with each other. The energy expended to overcome such frictional forces is considered an energy loss or frictional loss. When higher energy requirements are needed to overcome such losses, the amount of useful energy available to operate the engine often decreases. Current trends for improving engine and fuel efficiency include using friction reducing additives, friction reducing fuel additives, or surface coatings, among other things, to reduce frictional losses in the engine.

[0003] Friction-reducing additives, also known as friction modifiers, can be used as additives in lubricants to improve the efficiency of both engines and fuels. While lubricants are understood to reduce friction between moving surfaces, the addition of friction-reducing additives to lubricant compositions can further reduce friction losses without altering other physical properties of the lubricant, such as viscosity, density, and pour point. Furthermore, to meet the growing demand for more fuel-efficient vehicles, friction-reducing additives can be incorporated into fuel compositions. For example, a fuel composition containing a friction-reducing additive can be used to deliver friction-modulating properties to the piston ring-cylinder wall interface of an engine where friction is high but the amount of lubricant flowing into that area is low.

[0004] U.S. Patent No. 6,866,690 describes friction modifiers prepared in combination with saturated carboxylates and alkylated amines for use in flammable fuel compositions. The friction modifiers can be prepared, for example, by mixing (i) branched saturated carboxylic acids or mixtures thereof with (ii) mono- and / or dialkylated monoamines, and / or mono- and / or dialkylated polyamines, in a molar ratio of approximately 1:1. The boundary friction coefficients for the described friction modifiers were measured using a PCS Instruments high-frequency reciprocating rig, in which a load of 4 Newtons (N) was applied between a 6 mm diameter ANSI 52100 steel ball and an ANSI 52100 flat rope.

[0005] U.S. Patent No. 9,011,556 describes an intermediate distillate fuel composition containing hydrocarbyl-substituted succinimide in a friction-modifying amount. The intermediate distillate fuel composition was subjected to a high-frequency reciprocating rig (HFRR) as described in ASTM Method D6079, and the average HFRR wear mark diameter was recorded.

[0006] U.S. Patent No. 6,835,217 describes a fuel composition comprising a hydrocarbon fuel and a friction modifier component which is a reaction product of at least one natural or synthetic oil and at least one alkanolamine. Lubricity tests were performed using a high-frequency reciprocating rig (HFRR) as described in ASTM Method D6079-97, and wear mark diameter measurements were calculated based on the long and short axes.

[0007] U.S. Patent Publication 2011 / 0146143 describes a fuel composition containing a friction-reducing component for use in an internal combustion engine. The friction-reducing component comprises at least one C6-C, including saturated fatty acid amines, unsaturated fatty acid amines, and mixtures thereof. 30 Contains aliphatic amines. The friction coefficient and wear mark performance of the components were measured using an SRV test rig. [Overview of the project] [Problems that the invention aims to solve]

[0008] Many internal engine components, such as fuel pumps and injectors, are prone to excessive wear and metal damage (i.e., corrosion and erosion) due to friction. Excessive friction often leads to shorter engine life, higher engine replacement costs, and inefficient fuel economy, as it requires more fuel to operate the engine. However, the aforementioned friction-reducing additives offer only slight improvements in overcoming these challenges and other issues related to engine and fuel performance. Therefore, to meet the continuing demand for improved friction reduction, there is a need for fuel compositions that provide exemplary lubrication properties and superior protection against engine friction loss, wear, deposits, and corrosion. [Means for solving the problem]

[0009] Therefore, the present invention relates to improved fuel compositions. More specifically, each fuel composition of the present invention contains a hydrocarbon-based fuel and a lubricating additive. According to the present invention, the fuel composition specifically comprises gasoline as the base fuel and a lubricating additive selected from 1-lauroyl-rac-glycerol, dodecanamide, N-hydroxy-, or 2-ethylhexanoic acid.

[0010] The present invention further relates to a method for improving the lubricity of a fuel composition. In particular, the method includes adding a soluble lubricating additive to a hydrocarbon-based fuel to form a fuel composition having improved lubricity. According to the present invention, the method specifically includes adding a lubricating additive selected from 1-lauroyl-rac-glycerol, dodecanamide, N-hydroxy-, or 2-ethylhexanoic acid to gasoline selected as a preferred base fuel.

[0011] The present invention also relates to a method for improving the fuel performance of a direct injection engine. More specifically, the present invention describes a method for fueling a direct injection engine with a fuel composition comprising a hydrocarbon-based fuel and a lubricating additive. According to the present invention, a fuel composition used in a direct injection engine comprises gasoline as a base fuel and a lubricating additive selected from one of 1-lauroyl-rac-glycerol, dodecanamide, N-hydroxy-, or 2-ethylhexanoic acid. [Brief explanation of the drawing]

[0012] Specific exemplary embodiments will be described with reference to the following detailed description and drawings.

[0013] [Figure 1A] This graph shows the friction coefficient for fuel compositions at a processing speed of 50 ppm (wt / v) during trial operation from 0 to 4500 seconds. [Figure 1B] This graph shows the friction coefficient for fuel compositions at a processing speed of 50 ppm (wt / v) during test runs lasting 900 to 4500 seconds. [Figure 2]This graph compares the friction coefficients of fuel compositions at processing speeds of 50 ppm (wt / v) and 25 ppm (wt / v) during test runs lasting 900 to 4500 seconds. [Figure 3] This is a graph showing the wear mark values ​​for fuel compositions at 50 ppm (wt / v). [Figure 4] This graph compares the wear mark values ​​for fuel compositions at processing speeds of 50 ppm (wt / v) and 25 ppm (wt / v). [Figure 5] This is a graph comparing wear marks and friction coefficient data for each fuel composition. [Modes for carrying out the invention]

[0014] Moving mechanical assemblies, such as those in internal combustion engines, are prone to friction losses, which constitute a large portion of engine inefficiency. Friction losses occur between engine components such as the crankshaft, bearings, pistons, piston rings, piston skirts, valves and valve guides, pulleys, timing belts, and connecting rods. Reciprocating parts, such as pistons and piston rings, are the largest contributors, accounting for up to 50% of all friction losses between various engine components. While it is impossible to completely eliminate friction that occurs during engine operation, applications such as lubricants, surface coatings, and fuels are typically used to reduce friction losses. Lubricants generally reduce friction based on their behavior upon surface contact and / or their ability to impose viscous shear stress on moving engine components. Current trends by some automakers include the development of surface coatings that also reduce the coefficient of friction. In addition, certain fuel compositions are formulated to reduce friction losses between moving components.

[0015] The present invention relates to several fuel compositions, each comprising a specific lubricating additive. Specifically, each embodiment of the fuel composition comprises a hydrocarbon-based fuel and a selected lubricating additive for reducing friction due to surface adsorption when the composition comes into contact with moving engine parts. For example, the lubricating additive of the fuel composition of the present invention, upon entering the combustion chamber, adsorbs onto the oil film on the engine wall of the combustion chamber, acting as an anti-friction layer between moving parts, preventing metal-to-metal contact and thus reducing friction loss during surface contact.

[0016] There are areas of the engine, such as the engine bearing compartment, that are in contact with or directly in contact with lubricating oil. However, there are engine components that come into contact with the fuel composition rather than the lubricant (i.e., non-lubricated wetted components) that could potentially benefit from improved lubrication properties. In this embodiment, the fuel composition of the present invention acts as a lubrication source for internal engine components that are both lubricated and non-lubricated. For example, the lubricating additives of the fuel composition of the present invention may flow unchanged from the combustion chamber into the oil sump, accumulate over time, and mix with the engine lubricant, i.e., engine oil, in the oil sump. In this regard, the fuel composition of the present invention acts as an additional lubricant source for lubricated wetted components such as camshafts, crankshafts, and intake valves. In addition, in port fuel injection (PFI) engines, the intake valves are exposed to fuel just before entering the combustion chamber. Therefore, exposure to the current fuel composition not only helps to remove deposit formation but also helps to lubricate the valve stems in the valve guides. Nevertheless, there are several areas in the engine, such as the fuel injectors and fuel pumps, and the fuel composition of the present invention delivers lubricating additives that reduce friction while intentionally maintaining the amount of lubricant at a minimum level. Overall, the fuel composition of the present invention, including lubricating additives, substantially reduces friction between a wide range of moving engine parts, particularly towards the end of the oil drain interval when the chemical properties of the lubricant are depleted and no longer effective.

[0017] Surprisingly, the engines using the fuel compositions of the present invention have shown significant engine improvements including reduction of friction loss and improvement of wear resistance compared to engines using fuel compositions containing conventional friction reducing additives or only the base fuel. For example, the test data for each fuel composition of the present invention showed convincing improvement in lubricity as indicated by reduction of the coefficient of friction and wear scar values compared to those of typical fuels. Each fuel composition of the present invention containing a lubricity additive also showed synergistic behavior with respect to improved engine protection including lower engine deposits and corrosion behavior. It is well known to those skilled in the art that reduction of friction loss often leads to higher engine output and better fuel efficiency. Thus, another advantage provided by the fuel compositions of the present invention includes increased fuel performance and improved fuel economy.

[0018] As used herein, the term "lubricity" refers to the ability or property of a fuel composition to reduce friction between engine component parts.

[0019] As used herein, the term "lubricity additive" or "lubricity improver" refers to an additive that is added to a base fuel composition to improve lubricating properties and thus results in reduction of friction, wear, deposits, and corrosion between engine component parts.

[0020] The base fuel of the present fuel composition includes hydrocarbon-based fuels suitable for use in spark-ignition (petrol) type internal combustion engines known in the art, including automotive engines and other types of engines such as off-road and aviation engines. Preferably, the base fuel includes gasoline or gasoline-based fuels referred to herein as "gasoline". For example, the base fuel may include common blends of gasoline and ethanol, such as E85 fuel containing 15% gasoline and 85% ethanol. The amount of gasoline in the fuel can vary based on geographical region and season (typically 15% to 90% by volume), thereby including ethanol contents in the range of E10 to E85.

[0021] Gasoline can contain volatile hydrocarbons that boil in the range of about 25°C (77°F) to about 220°C (428°F) and can be derived from straight-run naphtha, polymer gasoline, natural gasoline, catalytically or thermally cracked hydrocarbons, catalytically reformed stocks, or mixtures thereof. Also, gasoline blend components derived from biological sources are also suitable for use.

[0022] The volatile hydrocarbons can be selected from one or more of the following groups, including saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, oxygenated hydrocarbons, and mixtures thereof. The octane number of gasoline generally exceeds about 85. The specific hydrocarbon composition and octane number of the base fuel are not important in this embodiment.

[0023] Typically, the saturated hydrocarbon content of gasoline ranges from 40% to about 80% by volume, and the oxygenated hydrocarbon content ranges from 0% to about 35% by volume. When gasoline contains oxygenated hydrocarbons, at least a portion of the unoxygenated hydrocarbons are replaced by oxygenated hydrocarbons. The oxygen content of gasoline can be up to 35% by weight (EN1601) based on gasoline (e.g., ethanol itself). For example, the oxygen content of gasoline can be up to 25% by weight, preferably up to 10% by weight. For convenience, the oxygenated hydrocarbon concentration has a minimum concentration selected from any one of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2% by weight, and a maximum concentration selected from any one of 5, 4.5, 4.0, 3.5, 3.0, and 2.7% by weight.

[0024] Typically, the olefinic hydrocarbon content of gasoline is in the range of 0% to 40% by volume based on gasoline (ASTM D1319). Preferably, the olefinic hydrocarbon content is in the range of 0% to 30% by volume based on gasoline, and more preferably, the olefinic hydrocarbon content is in the range of 0% to 20% by volume based on gasoline. The aromatic hydrocarbon content of gasoline is in the range of 0% to 70% by volume based on gasoline (ASTM D1319). For example, the aromatic hydrocarbon content of gasoline is in the range of 10% to 60% by volume based on gasoline. Preferably, the aromatic hydrocarbon content of gasoline is in the range of 10% to 50% by volume based on gasoline, and more preferably, the aromatic hydrocarbon content is in the range of 10% to 50% by volume based on gasoline.

[0025] Gasoline may also contain mineral carrier oils, synthetic carrier oils, mixtures thereof, and / or solvents. Examples of suitable mineral carrier oils include fractions obtained from crude oil processing, such as bright stock or base oil, and fractions obtained from refining mineral oils, such as hydrocrack oil. Examples of suitable synthetic carrier oils include polyolefins (poly-alpha-olefins or poly(internal olefins)), (poly)esters, (poly)alkoxylates, polyethers, aliphatic polyetheramines, alkylphenol-initiated polyethers, alkylphenol-initiated polyetheramines, and carboxylic acid esters of long-chain alkanols.

[0026] Suitable examples of polyolefins are olefin polymers, particularly olefin polymers based on polybutene or polyisobutene (hydrogenated or non-hydrogenated). Suitable examples of polyethers or polyetheramines are preferably C2-C 60 - Alkanol, C6~C 30 -Alkanediol, mono- or di-C2~C 30 -alkylamines, C1~C 30 -Alkylcyclohexanol, or C1-C 30 - Compounds containing a polyoxy-C2-C4 alkylene moiety, which can be obtained by reacting an alkylphenol with 1 to 30 moles of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group, and, in the case of polyetheramines, by subsequent reductive amination with ammonia, monoamine, or polyamine.

[0027] Examples of carboxylic acid esters of long-chain alkanols are, in particular, esters of mono-, di-, or tricarboxylic acids with long-chain alkanols or polyols. The mono-, di-, or tricarboxylic acids used may be aliphatic or aromatic acids, and preferred ester alcohols or polyols are, in particular, representative long-chain compounds having 6 to 24 carbon atoms. Typical representative esters include adipates, phthalates, isophthalates, terephthalates, and trimellitates of isooctanol, isononanol, isodecanol, and isotridecanol, such as di-(n- or isotridecyl)phthalate.

[0028] Other examples of suitable synthetic carrier oils are alcohol-initialized polyethers having about 5 to 35 C3-C6 alkylene oxide units, selected from, for example, propylene oxide, n-butylene oxide, and isobutylene oxide units, or mixtures thereof. Non-limiting examples of suitable initial alcohols include long-chain alkyl radicals in certain linear or branched C6-C6 configurations. 18 -A long-chain alkanol or phenol substituted with a long-chain alkyl, which is an alkyl radical; preferred examples include tridecanol and nonylphenol.

[0029] The benzene content of the gasoline is, based on the gasoline, at most 10% by volume, more preferably at most 5% by volume, and most preferably at most 1% by volume. The gasoline preferably has a low or very low sulfur content, for example, at most 1000 ppmw (parts per million by weight), preferably 500 ppmw or less, more preferably 100 or less, even more preferably 50 or less, and most preferably even more preferably 10 ppmw or less. The gasoline also preferably has a low total lead content, such as at most 0.005 grams / liter (g / l), and most preferably does not contain lead, and therefore no lead compounds are added to the gasoline (i.e., it is unleaded). The gasoline used in the present invention may be substantially water-free, as water can interfere with smooth combustion.

[0030] Each fuel composition of the present invention comprises only one type of lubricating additive. In this regard, the lubricating additives are selected as individual components from commercially available 1-lauroyl-rac-glycerol, dodecanamide, and N-hydroxy- or 2-ethylhexanoic acid, and each additive is selected based on its ability to effectively improve lubricity. In this embodiment, each lubricating additive is sufficiently soluble in the base fuel to produce the fuel composition, preferably completely soluble, and does not interfere with or impose negative interactions with other additives that may be optionally added to the composition. Each individual lubricating additive is blended with its respective base fuel at a concentration of about 5 ppm (parts per million) to about 100 ppm by weight, based on the total weight of the fuel composition.

[0031] Each lubricating additive molecule contains a polar head group and a nonpolar tail group. The polar head group of the molecule is attracted to metal surfaces and therefore bonds relatively strongly, but is reversible to such surfaces, i.e., can be lifted and moved. With surface modification or impregnation of ceramic fibers, the polar head group can be attracted to other surfaces, such as alumina surfaces. The nonpolar tail group of the molecule can be slightly longer than the base fuel molecule, i.e., longer than 15 atoms, and can include nonlinear, branched, or curved configurations to allow molecular packing and fluid flow. Since the nonpolar tail group is hydrocarbon, the entire molecule can be solubilized in hydrocarbon-based fuels. Due to the properties of the polar head group and the structure of the nonpolar tail group of each lubricating additive, the fuel compositions of the present invention have a remarkable impact on engine efficiency and performance by reducing friction between engine components.

[0032] 1-Lauroyl-rac-glycerol is formed by a glycerol ester (polar head group) and a lauric acid derivative (non-polar tail group), as shown in (1). The glycerol ester is multifunctional and typically stable when grafted into acids. The lauric acid derivative typically contains molecules that are larger than the base fuel molecule but smaller than the molecules of conventional friction modifiers. [ka]

[0033] Dodecanamide, N-hydroxy- is an N-hydroxyamide derivative, as shown in (2), and is formed by an N-hydroxyamide (polar head group) and a lauric acid derivative (non-polar tail group). The suitability of N-hydroxyamides is based on their multifunctional behavior and compact molecular size. Lauric acid derivatives typically include molecules that are larger than the base fuel molecule but smaller than the molecules of conventional friction modifiers. [ka]

[0034] 2-ethylhexanoic acid is formed from a carboxylic acid (polar head group) and a 2-ethylhexanoic acid derivative (non-polar tail group), as shown in (3). The carboxylic acid is typically available with the proposed non-polar tail group. The 2-ethylhexanoic acid derivatives include branched molecules that are similar in size to the base fuel molecules. [ka]

[0035] Through surface adsorption, lubricating additives reduce the frictional properties of intermetallic interfaces. Specifically, the combination of a flexible, multifunctional head group and a slightly longer tail group allows selected lubricating additives, including 1-lauroyl-rac-glycerol, dodecanamide, and N-hydroxy-2-ethylhexanoic acid, to adhere to multiple sites or adsorb onto metal surfaces, thus exhibiting exemplary surface adhesion.

[0036] Although not essential to the present invention, the fuel gasoline composition of the present invention may further contain one or more optional fuel additives in addition to the selected lubricating additives described above. It should be noted that the concentration and properties of the optional fuel additives in the present invention are not important. However, the concentration of any optional fuel additive present in the fuel composition may be in the range of 90 to 1500 ppmw, preferably up to 1% by weight of the total fuel composition, more preferably in the range of 5 to 2000 ppmw, and most preferably in the range of 90 to 1000 ppmw. Non-limiting examples of optional fuel additives include, but are not limited to, antioxidants, corrosion inhibitors, detergents, dehasers, anti-knock additives, metal deactivators, valve seat setback protection compounds, dyes, solvents, carrier fluids, diluents, and markers.

[0037] The present invention is further described in detail by the following embodiments. In particular, each embodiment involves blending one of three different lubricity improvers with a base fuel to produce three different fuel compositions. The three lubricity improvers were added to their respective base fuels at part-of-50 million (ppm) by volume weight (wt / v) and at a processing rate of 25 ppm (wt / v). The three fuel compositions and the conventional base fuels were evaluated for friction and wear mark performance using a modified high-frequency reciprocating rig (HFRR) test method for gasoline (ASTM D6079-11). It should be noted that the embodiments are provided for illustrative purposes only and should not be construed as limiting the present invention in any way.

[0038] Example 1 Example 1 shows friction coefficient data for a base fuel and three different fuel compositions, each containing a separate lubricating additive, as shown in Table 1. The base fuel used in each fuel composition was E10, a 90% gasoline and 10% ethanol mixture that can be used in most automobile and small car internal combustion engines without modifying the engine or fuel system. The individual lubricating additives added to each base fuel included 1-lauroyl-rac-glycerol, dodecanamide, N-hydroxy- or 2-ethylhexanoic acid. No other additives were added. Thus, the formulations for each fuel composition tested were (1) base fuel only, (2) 1-lauroyl-rac-glycerol and base fuel, (3) dodecanamide, N-hydroxy- and base fuel, and (4) 2-ethylhexanoic acid and base fuel. The amount of each lubricating additive added to each base fuel was 50 ppm (wt / v) based on the total amount of base fuel.

[0039] The coefficient of friction for each fuel composition was determined using the HFRR (High Frequency Reciprocating Rig) test method every second during a 0-4500 second test run. The first 900 seconds of the 0-4500 second test run showed a spike in the coefficient of friction, followed immediately by a decrease in the coefficient. The formation of wear-resistant films, metal oxide films, or smoothing of irregularities on the metal surface may contribute to the initial spike. After the first 900 seconds, a more stable coefficient of friction was recorded during the remaining 900-4500 seconds of the test run, thereby ensuring a more stable platform for comparison. Thus, as shown in Table 1, the coefficient of friction results include the results for the entire 4500 seconds (i.e., 0-4500 seconds) and the results for the remaining 900-4500 seconds of the test run (i.e., 900-4500 seconds). The HFRR test in this embodiment was conducted at 25°C, but it can be conducted at various temperatures and can be programmed to suit the specific application of the fuel composition being tested. [Table 1]

[0040] Figure 1A shows a graphical representation of the coefficient of friction for fuel compositions at a processing speed of 50 ppm (wt / v) during a test run of 0–4500 seconds. Each fuel composition containing a lubricating additive showed a lower coefficient of friction than the base fuel without additives during the 0–4500 second test run, even though the coefficient of friction spiked during the first 900 seconds of the test run. As provided in Table 1 and shown in Figure 1A, the base fuel showed an average coefficient of friction of approximately 0.701. However, fuel composition number 2 (1-lauroyl-rac-glycerol + base fuel) showed a coefficient of friction of approximately 0.489, fuel composition number 3 (dodecanamide, N-hydroxy- + base fuel) showed a coefficient of friction of approximately 0.444, and fuel composition number 4 (2-ethylhexanoic acid + basic fuel) showed a coefficient of friction of approximately 0.464. When determined using the HFRR test method, each fuel composition provided an improvement in frictional properties by providing a lower coefficient of friction compared to the base fuel.

[0041] Figure 1B shows a graphical representation of the friction coefficients of fuel compositions at a processing speed of 50 ppm (wt / v) during test runs of 900–4500 seconds. As provided in Table 1 and shown in Figure 1B, each fuel composition containing lubricating additives exhibited a lower friction coefficient than the base fuel without additives during the 900–4500 second test runs. In particular, the base fuel exhibited an average friction coefficient of approximately 0.587. However, fuel composition number 2 (1-lauroyl-rac-glycerol + base fuel) exhibited a friction coefficient of approximately 0.393, fuel composition number 3 (dodecanamide, N-hydroxy- + base fuel) exhibited a friction coefficient of approximately 0.361, and fuel composition number 4 (2-ethylhexanoic acid + basic fuel) exhibited a friction coefficient of approximately 0.385. Each fuel composition provided an improvement in frictional properties by offering a lower friction coefficient compared to the base fuel.

[0042] Example 2 Example 2 presents comparative friction coefficient data for fuel compositions containing individual lubricating additives at a lower lubricating rate of 25 ppm (wt / v) compared to a lubricating rate of 50 ppm (wt / v), as shown in Table 2. The base fuels used in Example 2 are the same as those described for Example 1. Selected lubricating additives, including dodecanamide, N-hydroxy-, and 1-lauroyl-rac-glycerol, were added individually to their respective base fuels. No other additives were added. Thus, the tested formulations involved comparing fuel composition number 1 (dodecanamide, N-hydroxy- + base fuel) at a rate of 50 ppm (wt / v) with fuel composition number 2 (dodecanamide, N-hydroxy- + base fuel) at a rate of 25 ppm (wt / v). In addition, fuel composition number 3 (1-lauroyl-rac-glycerol + base fuel) at a processing rate of 50 ppm (wt / v) was compared with fuel composition number 4 (1-lauroyl-rac-glycerol + base fuel) at a processing rate of 25 ppm (wt / v). The coefficient of friction for each fuel composition was determined using the HFRR test method at one-second intervals during test runs ranging from 900 to 4500 seconds. [Table 2]

[0043] Figure 2 shows a graph comparing the coefficients of friction for fuel compositions at processing speeds of 50 ppm (wt / v) and 25 ppm (wt / v) during test runs of 900 to 4500 seconds. The effect of dose rate on the coefficient of friction parameter can be further understood by testing various fuel compositions at lower lubricity additive processing speeds. As provided in Table 2 and shown in Figure 2, fuel composition number 1 (dodecaneamide, N-hydroxy-+ base fuel) showed a coefficient of friction of approximately 0.361 at a processing speed of 50 ppm (wt / v), while fuel composition number 2 (dodecaneamide, N-hydroxy-+ base fuel) showed a coefficient of friction of approximately 0.382 at a processing speed of 25 ppm (wt / v). In addition, fuel composition number 3 (1-lauroyl-rac-glycerol + base fuel) showed a friction coefficient of approximately 0.393 at a processing rate of 50 ppm (wt / v), while fuel composition number 4 (1-lauroyl-rac-glycerol + base fuel) showed a friction coefficient of approximately 0.432 at a processing rate of 25 ppm (wt / v). In each case, the fuel composition containing the lubricating additive at a processing rate of 50 ppm (wt / v) showed a lower friction coefficient than the fuel composition containing the lubricating additive at a processing rate of 25 ppm (wt / v). However, as described with respect to Example 2, the friction coefficients for all fuel compositions were lower than the friction coefficient of approximately 0.587 for the base fuel, as provided in Example 1. Thus, each of the fuel compositions in Example 2 provided an improvement in frictional properties by providing a lower friction coefficient compared to the friction coefficient of the base fuel.

[0044] Example 3 Example 3 shows wear mark values ​​for three different fuel compositions containing a base fuel and individual lubricating additives, as shown in Table 3. The base fuel is described with respect to Example 1. The individual lubricating additives added to each base fuel included 1-lauroyl-rac-glycerol, dodecanamide, N-hydroxy- and 2-ethylhexanoic acid. No other additives were added. Therefore, the formulations for each fuel composition tested were (1) base fuel only, (2) 1-lauroyl-rac-glycerol and base fuel, (3) dodecanamide, N-hydroxy- and base fuel, and (4) 2-ethylhexanoic acid and base fuel. The amount of each lubricating additive added to each base fuel was 50 ppm (wt / v) based on the total amount of base fuel. Wear mark values ​​for each fuel composition were determined using the HFRR test method provided in micrometers (μm). [Table 3]

[0045] Figure 3 shows a graphical representation of wear mark data for fuel compositions at 50 ppm (wt / v). As provided in Table 3 and shown in Figure 3, each fuel composition containing a lubricating additive showed lower wear marks than the base fuel without the additive. In particular, the base fuel showed an wear mark of approximately 818.9 μm. However, fuel composition number 2 (1-lauroyl-rac-glycerol + base fuel) showed an wear mark of approximately 758.0 μm, fuel composition number 3 (dodecanamide, N-hydroxy- + base fuel) showed an wear mark of approximately 677.0 μm, and fuel composition number 4 (2-ethylhexanoic acid + base fuel) showed an wear mark of approximately 692.5 μm. The results provided by Example 3 show that the base fuel-only compositions exhibit greater wear marks, i.e., insufficient lubricity performance, compared to the three fuel compositions containing lubricating additives.

[0046] Example 4 Example 4 presents comparative wear mark data for fuel compositions containing individual lubricating additives, as shown in Table 4, at a lower processing rate of 25 ppm (wt / v) compared to a processing rate of 50 ppm (wt / v). The base fuels used in Example 4 are the same as those described for Example 1. Selected lubricating additives, including dodecanamide, N-hydroxy-, and 1-lauroyl-rac-glycerol, were added individually to their respective base fuels. No other additives were added. Thus, the tested formulations involved comparing fuel composition number 1 (dodecanamide, N-hydroxy- + base fuel) at a processing rate of 50 ppm (wt / v) with fuel composition number 2 (dodecanamide, N-hydroxy- + base fuel) at a processing rate of 25 ppm (wt / v). In addition, fuel composition number 3 (1-lauroyl-rac-glycerol + base fuel) at a processing rate of 50 ppm (wt / v) was compared with fuel composition number 4 (1-lauroyl-rac-glycerol + base fuel) at a processing rate of 25 ppm (wt / v). As provided in Example 4, the wear mark values ​​for each fuel composition were determined using the HFRR test method. [Table 4]

[0047] Figure 4 shows a graph comparing wear mark data for fuel compositions at processing speeds of 50 ppm (wt / v) and 25 ppm (wt / v). The effect of dose rate on wear mark data can be further understood by testing various fuel compositions at lower lubricity additive processing speeds. As provided in Table 4 and shown in Figure 4, fuel composition No. 1 (dodecaneamide, N-hydroxy-+ base fuel) showed an wear mark value of approximately 677.0 at a processing speed of 50 ppm (wt / v), while fuel composition No. 2 (dodecaneamide, N-hydroxy-+ base fuel) showed an wear mark value of approximately 756.0 at a processing speed of 25 ppm (wt / v). In addition, fuel composition number 3 (1-lauroyl-rac-glycerol + base fuel) showed an abrasion mark value of approximately 758.0 at a processing rate of 50 ppm (wt / v), while fuel composition number 4 (1-lauroyl-rac-glycerol + base fuel) showed an abrasion mark value of approximately 792.5 at a processing rate of 25 ppm (wt / v). In each case, the fuel composition containing the lubricating additive at a processing rate of 50 ppm (wt / v) showed a lower abrasion mark value than the one at a processing rate of 25 ppm (wt / v). However, as described in Example 4, the abrasion mark values ​​for all fuel compositions were lower than the abrasion mark value of approximately 818.9 for the base fuel, as provided in Example 3. Therefore, each of the fuel compositions in Example 4 provides improved wear by providing a reduction in the abrasion mark value compared to the abrasion mark value of the base fuel.

[0048] Figure 5 shows a graphical comparison of wear marks and friction coefficient data for each fuel composition. The compositions include a base fuel-only composition, a dodecanamide, N-hydroxy-+ base fuel composition, a 1-lauroyl-rac-glycerol+ base fuel composition, and a 2-ethylhexanoic acid+ base fuel composition. The wear marks and friction coefficients for each fuel composition of the present invention are plotted against the wear marks and friction coefficients for the base fuel-only composition. When such data are combined into a single plot, those skilled in the art can easily see that fuel compositions containing base fuel and lubricating additives provide both wear marks and friction reduction compared to base fuel compositions.

[0049] The object of the present invention included evaluating various lubricating additives that would increase the lubrication properties when added to gasoline fuel. The lubricating additives were selected based on the chemical properties of their unique additives, which include various polar and nonpolar groups, and were individually added to gasoline fuel to form fuel compositions, which were then tested to determine their level of lubricity. The results of Examples 1-4 show that the objective was achieved, with each fuel composition containing a lubricating additive demonstrating improved lubrication properties. When 1-lauroyl-rac-glycerol was added to the base fuel as a lubricating additive, improvements in friction loss and wear marks were observed, with friction coefficient data in the range of 0.390-0.500 and wear mark data in the range of 755-795 μm. When dodecanamide, N-hydroxy- was added to the base fuel as a lubricating additive, improvements in friction loss and wear marks were observed, with friction coefficient data in the range of 0.360-0.515 and wear mark data in the range of 675-757 μm. Adding 2-ethylhexanoic acid as a lubricant to the base fuel resulted in improvements in friction loss and wear marks. The friction coefficient data ranged from 0.385 to 0.465, and the wear mark data was approximately 692 μm.

[0050] The synergistic behavior demonstrated by the combination of gasoline-based fuel and selected lubricating additives shows improved engine efficiency and performance compared to using the base fuel alone. Such improved lubrication, including reduced friction losses and wear marks, provides improved protection for various components of direct-injection engines, such as high-pressure fuel pumps and injectors. Another remarkable benefit is that each fuel composition containing lubricating additives can also improve the fuel performance of direct-injection engines or engines suited to gasoline use at any given time.

[0051] While the technology of this invention can take various modifications and alternative forms, the exemplary examples described above are presented for illustrative purposes only. It should be understood that this technology is not intended to be limited to the specific examples disclosed herein. In fact, these embodiments include all alternatives, modifications, and equivalents within the scope of this technology. This specification includes the disclosure of the following inventions. [Item 1] Fuel and, It contains lubricating additives, A fuel composition in which the lubricating additive is selected from (1) 1-lauroyl-rac-glycerol, (2) dodecanamide, N-hydroxy-, or (3) 2-ethylhexanoic acid. [Item 2] The fuel composition according to Item 1, wherein the fuel is gasoline. [Item 3] The fuel composition according to Item 1, wherein the concentration of the lubricating additive is in the range of about 5 ppm by weight to about 100 ppm by weight, based on the total weight of the fuel composition. [Item 4] The fuel composition according to Item 1, wherein the lubricating additive is soluble in the fuel. [Item 5] The fuel composition according to Item 1, further comprising a coefficient of friction in the range of 0.390 to 0.500, where 1-lauroyl-rac-glycerol is the lubricating additive. [Item 6] The fuel composition according to Item 1, further comprising a coefficient of friction in the range of 0.360 to 0.515, where dodecanamide, N-hydroxyl- is the lubricating additive. [Item 7] The fuel composition according to Item 1, further comprising a wear mark diameter in the range of 755 μm to 795 μm, where 1-lauroyl-rac-glycerol is the lubricating additive. [Item 8] The fuel composition according to Item 1, further comprising a wear mark diameter in the range of 675 μm to 757 μm, where dodecanamide, N-hydroxyl- is the lubricating additive. [Item 9] The fuel composition according to Item 1, further comprising a friction coefficient in the range of 0.385 to 0.465 and an abrasion mark diameter of about 692 μm, where 2-ethylhexanoic acid is the lubricating additive. [Item 10] A method for improving the lubricity of a fuel composition, wherein the method is To provide fuel, The process for producing the fuel composition includes adding a lubricating additive to the fuel, The aforementioned fuel is gasoline, A method wherein the lubricating additive is selected from (1) 1-lauroyl-rac-glycerol, (2) dodecanamide, N-hydroxy-, or (3) 2-ethylhexanoic acid. [Item 11] The method according to Item 10, wherein the concentration of the lubricating additive is in the range of about 5 ppm by weight to about 100 ppm by weight, based on the total weight of the fuel composition. [Item 12] The method according to Item 10, wherein the fuel composition contains a coefficient of friction in the range of 0.360 to 0.515 after the lubricating additive has been added to the fuel. [Item 13] The method according to Item 10, wherein the fuel composition contains wear mark diameters in the range of 675 μm to 795 μm after the lubricating additive has been added to the fuel. [Item 14] A method for improving the fuel performance of a direct injection engine, wherein the method is The fuel composition comprising fuel and lubricating additives is used to supply fuel to the direct injection engine, This includes operating the aforementioned direct injection engine, The aforementioned fuel is gasoline, A method wherein the lubricating additive is selected from (1) 1-lauroyl-rac-glycerol, (2) dodecanamide, N-hydroxy-, or (3) 2-ethylhexanoic acid. [Item 15] The method according to Item 14, wherein the fuel composition, after mixing the lubricating additive with the fuel, has a coefficient of friction in the range of 0.360 to 0.515 and an abrasion mark diameter in the range of 675 μm to 795 μm.

Claims

1. The base fuel is a blend of gasoline and ethanol, and contains 10% to 85% by volume of ethanol. The fuel composition includes a lubricating additive in an amount ranging from 25 ppm by weight to 100 ppm by weight, based on the total weight of the fuel composition. A fuel composition wherein the lubricating additive consists of 1-lauroyl-rac-glycerol and is soluble in the base fuel.

2. The fuel composition according to claim 1, having a coefficient of friction in the range of 0.390 to 0.500 in the HFRR test (ASTM D6079-11).

3. The fuel composition according to claim 1, wherein the abrasion mark diameter in the range of 755 μm to 795 μm in the HFRR test (ASTM D6079-11).

4. A method for improving the lubricity of a fuel composition, wherein the method is To provide base fuel, The process for producing the fuel composition includes adding a lubricating additive to the base fuel in an amount ranging from 25 ppm by weight to 100 ppm by weight, based on the total weight of the fuel composition. The base fuel is a blend of gasoline and ethanol, containing 10% to 85% by volume of ethanol. A method wherein the lubricating additive consists of 1-lauroyl-rac-glycerol and is soluble in the base fuel.

5. The method according to claim 4, wherein the fuel composition has a coefficient of friction in the range of 0.360 to 0.515 in an HFRR test (ASTM D6079-11) after the lubricating additive has been added to the base fuel.

6. The method according to claim 4, wherein the fuel composition, after adding the lubricating additive to the base fuel, has an abrasion mark diameter in the range of 675 μm to 795 μm in an HFRR test (ASTM D6079-11).

7. A method for improving the fuel performance of a direct injection engine, wherein the method is The fuel composition comprising a base fuel and a lubricating additive is used to supply fuel to the direct injection engine, This includes operating the aforementioned direct injection engine, The base fuel is a blend of gasoline and ethanol, containing 10% to 85% by volume of ethanol. A method wherein the lubricating additive consists of 1-lauroyl-rac-glycerol, is present in an amount of 25 to 100 ppm, and is soluble in the base fuel.

8. The method according to claim 7, wherein the fuel composition, after mixing the lubricating additive with the base fuel, has a coefficient of friction in the range of 0.360 to 0.515 and an abrasion mark diameter in the range of 675 μm to 795 μm in an HFRR test (ASTM D6079-11).

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