Fuel composition

Abstract

A fuel composition comprising: (a) a base fuel suitable for use in an internal combustion engine; and (b) a tetraalkylethane compound having formula (I), wherein Ar represents an aryl group and each X is independently a hydrogen atom, a substituted or unsubstituted linear or branched C-C 12 Alkyl group, (CH2) n OH or (CH2) n NH2, where n is in the range of 1 to 9, with the proviso that at least one of the X groups in each CX3 group is a hydrogen atom; and c) alkylbenzene compounds having the formula (II), where each R1 to R6 group is independently selected from hydrogen and C1-C 15 and an alkylbenzene compound, wherein at least one of the R1-R6 groups is a C1-C6 alkyl group. The fuel composition of the present invention provides improved power and acceleration benefits, as well as increased flame speed and burn duration.

Description

[Technical field]

[0001] The present invention relates to a liquid fuel composition, in particular to a liquid fuel composition having improved power and / or acceleration properties. The present invention also relates to a method of improving the power and / or acceleration properties of an internal combustion engine by fuelling the engine with a liquid fuel composition as described herein below. [Background technology]

[0002] Laminar burning velocity (also referred to as "flame speed") is a fundamental combustion characteristic of any fuel / air mixture. As taught in SAE 2012-01-1742, formulating gasoline fuel blends with faster burning velocities can be an effective strategy for improving engine and vehicle performance. Faster burning fuel can result in more optimal combustion phasing, resulting in more efficient energy transfer and thus faster acceleration and better performance.

[0003] Increasing the ignition delay time (IDT) sufficiently to allow optimization of the spark timing during the power stroke in a spark-ignition internal combustion engine (SI-ICE) provides the best opportunity to calibrate for optimal efficiency. In addition, if the fuel is modified such that an increase in ignition delay time suppresses the chemical radical reactions that occur before the spark and causes these same reactions to shift further up the temperature / pressure trajectory of the cycle where these same reactions occur after the spark, improved combustion can be achieved through increased flame speed resulting in shorter combustion duration. The ability to collectively control flame speed and combustion duration allows the SI-ICE to be calibrated to achieve the best balance between fuel economy, power, and acceleration, expressed as the term "break thermal efficiency" (BTE). Summary of the Invention

[0004] Surprisingly, it has been found that the use of certain combinations of additive components in liquid fuel compositions can provide benefits in terms of increased flame speed, reduced burn duration, increased burn rate, improved power, improved acceleration performance, and improved fuel economy. Surprisingly, the present invention achieves this without affecting ignition delay time (IDT).

[0005] According to the present invention there is provided a fuel composition comprising: (a) a base fuel suitable for use in an internal combustion engine; (b) a tetraalkylethane compound having the formula (I):

[0006] [ka] wherein Ar represents an aryl group; each X is independently a hydrogen atom, a substituted or unsubstituted linear or branched C 1 -C 6 Alkyl groups, OH, (CH 2 ) n OH, (CH 2 ) n NH 2 wherein n is 1 to 9, except that each C—X 3 a tetraalkylethane compound in which at least one of the X groups is a hydrogen atom; c) an alkylbenzene compound having the formula (II),

[0007] [ka] wherein each R1 to R6 group is independently selected from hydrogen and C 1 -C 6 alkyl group, wherein at least one of the R1 to R6 groups is selected from the group 1 -C 6 and an alkylbenzene compound, the alkyl group being an alkyl group.

[0008] Surprisingly, it has been found that the fuel compositions of the present invention provide increased flame speed, reduced burn duration, increased burn rate, improved power, and improved acceleration performance. Surprisingly, the present invention achieves this without affecting ignition delay time (IDT).

[0009] According to another aspect of the present invention, there is provided a method of improving power output of an internal combustion engine, the method comprising fuelling the internal combustion engine with a liquid fuel composition as described herein below.

[0010] According to yet another aspect of the present invention, there is provided a method of improving the acceleration of an internal combustion engine, the method comprising fuelling the internal combustion engine with a liquid fuel composition as described herein below.

[0011] According to yet another aspect of the present invention, there is provided a method of increasing the flame speed of a liquid fuel composition in an internal combustion engine, the method comprising fuelling the internal combustion engine with a liquid fuel composition as described herein below.

[0012] According to yet another aspect of the present invention there is provided a method for reducing the combustion duration of a liquid fuel composition in an internal combustion engine, the method comprising fuelling the internal combustion engine with a liquid fuel composition as described herein below.

[0013] According to yet another aspect of the present invention, there is provided a method of increasing the combustion rate of a liquid fuel composition in an internal combustion engine, the method comprising fuelling the internal combustion engine with a liquid fuel composition as described herein below.

[0014] According to yet another aspect of the present invention there is provided a use of a liquid fuel composition as described herein for improving power output.

[0015] According to yet another aspect of the present invention there is provided a use of a liquid fuel composition as described herein for improving acceleration.

[0016] According to yet another aspect of the present invention there is provided a use of a liquid fuel composition for increasing flame speed.

[0017] According to yet another aspect of the present invention there is provided a use of a liquid fuel composition for reducing combustion duration. [Brief description of the drawings]

[0018] [Figure 1] 5 is a graphical representation of the experimental data set forth in Table 4. [Diagram 2] 1 is a graphical representation of the experimental data set forth in Table 5. [Diagram 3] 1 is a graphical representation of the experimental data set forth in Table 6 for Examples 1-4. [Figure 4] 1 is a graphical representation of the experimental data set forth in Table 7 for Examples 1-5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] To facilitate the understanding of this invention, a number of terms are defined herein.

[0020] As used herein, the term "power" refers to the amount of resistive power required to maintain a fixed speed at wide open throttle conditions in a chassis dynamometer test.

[0021] According to the present invention, there is provided a method for improving the power output of an internal combustion engine, the method comprising fueling an internal combustion engine containing a lubricant with a liquid fuel composition as described herein below. In the context of this aspect of the present invention, the term "improve" encompasses any degree of improvement. The improvement can be, for example, 0.05% or more, preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.5% or more, particularly 1% or more, even more particularly 2% or more, and even more particularly 5% or more of the power output of a similar fuel blend before adding tetraalkylethane compounds and also alkylbenzene compounds to the fuel blend according to the present invention. The improvement in power output can even be as high as 10% of the power output of a similar fuel blend before adding tetraalkylethane compounds and alkylbenzene compounds to the fuel blend according to the present invention.

[0022] In accordance with the present invention, the power output provided by a fuel composition may be determined in any known manner.

[0023] As used herein, the term "acceleration" refers to the amount of time required for an engine to increase speed between two fixed speed conditions in a given gear.

[0024] According to the present invention, there is provided a method for improving the acceleration of an internal combustion engine, the method comprising fueling an internal combustion engine containing a lubricant with a liquid fuel composition as described herein below. In the context of this aspect of the present invention, the term "improve" encompasses any degree of improvement. The improvement can be, for example, 0.05% or more of the acceleration provided by a similar fuel blend before adding tetraalkylethane compounds and alkylbenzene compounds to the fuel blend according to the present invention, preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.5% or more, particularly 1% or more, even more particularly 2% or more, and even more particularly 5% or more. The improvement in acceleration can even be as high as 10% of the acceleration provided by a similar fuel blend before adding tetraalkylethane compounds and alkylbenzene compounds to the fuel blend according to the present invention.

[0025] In accordance with the present invention, the power and acceleration provided by a fuel composition may be determined in any known manner, for example, using standard test methods such as those described in SAE Paper 2005-01-0239 and SAE Paper 2005-01-0244.

[0026] "Flame speed" or "laminar flame speed" (LFS) as used herein refers to laminar burning velocity. LFS is a basic measure of flame spread rate without the complications of mixing dynamics. However, in engines, mixing dynamics play a role, so the measured flame speed is referred to as "burn rate" and "burn duration". The terms "burn rate" and "burn duration" are also used interchangeably with "flame speed" herein. Laminar Burning Velocity (LBV) is a fundamental property of chemical composition. It is defined as the rate at which unburned gases propagate to the flame front and react to form products (perpendicular to the flame front under laminar conditions).

[0027] According to the present invention, there is provided a method for increasing the flame speed of an internal combustion engine, the method comprising fueling the internal combustion engine with a liquid fuel composition as described herein below. In the context of this aspect of the present invention, the term "increase" includes any degree of increase. The increase can be, for example, 0.05% or more, preferably 0.1% or more, more preferably 1% or more, and especially 5% or more of the flame speed of a similar fuel formulation before adding the additive claimed according to the present invention to the fuel formulation. The increase in flame speed can be up to 10% of the flame speed of a similar fuel formulation before adding the additive claimed according to the present invention to the fuel formulation.

[0028] However, it should be understood that any measurable improvement in power, acceleration, and flame speed may provide a worthwhile advantage depending on what other factors are deemed important, e.g., availability, cost, safety, etc.

[0029] According to the present invention, the flame speed of a fuel composition may be determined in any known manner, for example, measurement of the LFS may be performed using any one of the following three methods: 1. Stagnant fire method (maximum 5-7 atmospheres) 2. Spherical expansion method, constant pressure or constant volume (maximum 60-80 atmospheres) 3.Heat flux method (up to about 5 atmospheres).

[0030] All three of these methods are described in the review publication: Egolfopoulos, FN, Hansen, N., Ju, Y., Kohse-Hoinghaus, K., Law, C.K., and Qi, F. "Advances and challenges in laminar flame experiments and implications for combustion chemistry", Progress in Energy and Combustion Science 43(2014)36-67, https: / / doi.org / 10.1016 / j.pecs.2014.04.004.

[0031] See the following method for measuring flame speed in a constant volume combustion chamber (spherical bomb), Gillespie, LL, M.; Sheppard, CG; Wooley, R, Aspects of laminar and turbulent burning velocity relevant to spark ignition engines, Journal of the Society of Automotive Engineers, 2000 (2000-01-0192).

[0032] The following method for measuring flame speed uses the net pressure method: Mittal, M., Zhu, G. and Schock H., 'Fast mass-fraction-burned calculation using the net pressure method for real-time applications', Proc. Instn Mech Engrs, Part D: J. Automobile Engineering 223(3)(2009):389-394.

[0033] As used herein, the term "combustion duration" refers to the time (in engine crank degrees) required for combustion to progress from 10% to 90% (referred to as AI 10-90 in the following examples). In the following examples, the term AI 50-90 is also used in reference to combustion duration to refer to the time (in engine crank degrees) required for combustion to progress from 50% to 90%.

[0034] In accordance with the present invention, the burn duration of a fuel composition may be determined in any known manner, for example, using the test methods disclosed in the Examples section herein below.

[0035] However, it should be understood that any measurable improvement in power, acceleration, burn duration, and flame speed may provide a valuable advantage depending on what other factors are deemed important, e.g., availability, cost, safety, etc.

[0036] The liquid fuel composition of the present invention comprises a base fuel suitable for use in an internal combustion engine, a tetraalkylethane compound, and an alkylbenzene compound. Typically, the base fuel suitable for use in an internal combustion engine is a gasoline or diesel fuel, and thus the liquid fuel composition of the present invention is typically a gasoline or diesel fuel composition.

[0037] As used herein, a tetraalkylethane compound is a compound having the formula (I):

[0038] [ka] In the formula, Ar represents an aryl group, and each X is independently a hydrogen atom, a substituted or unsubstituted linear or branched C 1 -C 12 Saturated or unsaturated alkyl groups, (CH 2 ) n OH, (CH 2 ) n NH 2 wherein n is in the range of 1 to 9, preferably in the range of 1 to 6, more preferably in the range of 1 to 4, and even more preferably in the range of 1 to 3, with the proviso that each CX 3 At least one of the X groups in the group is a hydrogen atom.

[0039] Preferably, each CX 3 At least two of the X groups in the group are hydrogen atoms.

[0040] In a particularly preferred embodiment, each CX 3 Three of the X groups in the group are hydrogen atoms.

[0041] Preferably, Ar of the tetraalkylethane compound is a substituted or unsubstituted aromatic group such as phenyl, biphenyl, naphthyl, thienyl, or anthracyl. More preferably, Ar is an unsubstituted phenyl group. This means that for the preparation of the preferred compounds of formula (I), it is possible to start from cumene, which is commercially available. Starting from cumene, dicumene can be prepared by several known methods, as described in U.S. Pat. No. 4,072,811.

[0042] Preferably, each X group is independently selected from a hydrogen atom and an unsubstituted, linear or branched, saturated or unsaturated C 1 -C 6 , more preferably C 1 -C 3 , and alkyl groups, with the proviso that each C 3 At least one of the X groups in the group is a hydrogen atom.

[0043] More preferably, each X group is independently selected from a hydrogen atom and an unsubstituted, linear or branched, saturated C 1 -C 6 , preferably C 1 -C 3 , and alkyl groups, with the proviso that each C 3 At least one of the X groups in the group is a hydrogen atom.

[0044] In one embodiment, each X group is independently selected from hydrogen atoms and unsubstituted straight chain, saturated C 1 -C 6 , preferably C 1 -C 3 , alkyl groups, in particular methyl, ethyl and propyl.

[0045] Examples of suitable tetraalkylethane compounds of formula (I) include:

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] In one embodiment herein, the tetraalkylethane compound is 1,1'(1,1,2,2-tetramethyl-1,1-ethanediyl)bis-benzene (dicumene). Dicumene is commercially available from Aldrich and various other chemical suppliers.

[0050] The tetraalkylethane compound is preferably present in the fuel composition at a level from 30 ppm to 10% by weight of the fuel composition, preferably from 100 ppm to 5% by weight, more preferably from 100 ppm to 1% by weight, even more preferably from 100 ppm to 5000 ppm, especially from 500 ppm to 2000 ppm.

[0051] In addition to the tetraalkylethane compounds described above, the fuel compositions of the present invention also contain an alkylbenzene compound having the following formula (II):

[0052] [ka] wherein each R1 to R6 group is independently selected from hydrogen and C 1 -C 6 alkyl group, wherein at least one of the R1 to R6 groups is selected from 1 -C 6 It is an alkyl group.

[0053] It has been discovered that improvements in power, acceleration, flame speed and burn duration characteristics can be obtained by using a combination of a tetraalkylethane compound and an alkylbenzene compound.

[0054] In a preferred embodiment of the present invention, the three R1-R6 groups in the alkylbenzene compound are independently selected from the group consisting of C 1 -C 6 The alkyl group is selected from the group consisting of aryl, ... and alkyl groups.

[0055] In a preferred embodiment herein, the alkylbenzene compound is a trimethylbenzene compound.

[0056] In a particularly preferred embodiment herein, the alkylbenzene compound is 1,3,5-trimethylbenzene, which is commercially available from Aldrich and other chemical suppliers.

[0057] The alkylbenzene compound is preferably present in the fuel composition at a level from 30 ppm to 2% by weight of the fuel composition, preferably from 100 ppm to 1% by weight, more preferably from 100 ppm to 5000 ppm, even more preferably from 500 ppm to 2000 ppm.

[0058] The tetraalkylethane compound and the alkylbenzene compound may be blended together with any other additives, such as an additive performance package, to produce an additive blend, which is then added to a base fuel to produce a liquid fuel composition.

[0059] The amount of performance package in the additive blend is preferably in the range of 0.1 to 99.8% by weight of the additive blend, more preferably in the range of 5 to 50% by weight.

[0060] Preferably, the amount of the performance package present in the liquid fuel composition of the present invention is in the range of from 15 ppmw (parts per million by weight) to 10% by weight, based on the total weight of the liquid fuel composition. More preferably, the amount of the performance package present in the liquid fuel composition of the present invention further complies with one or more of the parameters (i) to (xv) listed below. (i) At least 100 ppmw (ii) At least 200 ppmw (iii) At least 300 ppmw (iv) At least 400 ppmw (v) At least 500 ppmw (vi) At least 600 ppmw (vii) At least 700 ppmw (viii) At least 800 ppmw (ix) At least 900 ppmw (x) At least 1,000 ppmw (xi) At least 2,500 ppmw (xii) Maximum 5000ppmw (xiii) Maximum 10000ppmw (xiv) Maximum 2% by weight (xv) up to 5% by weight

[0061] When the base fuel used in the liquid fuel composition of the present invention is gasoline, the gasoline may be any gasoline suitable for use in internal combustion engines of the spark ignition (petroleum) type known in the art, including automobile engines, as well as other types of engines, such as, for example, off-road and aviation engines. For convenience, the gasoline used as the base fuel in the liquid fuel composition of the present invention may also be referred to as "base gasoline".

[0062] Gasoline typically comprises a mixture of hydrocarbons boiling in the range of 25-230°C (EN-ISO 3405), with optimum ranges and distillation curves typically varying depending on the climate and the season of the year. The hydrocarbons in gasoline may be derived by any means known in the art, conveniently the hydrocarbons may be derived in any known manner from straight run gasoline, synthetically produced aromatic hydrocarbon mixtures, thermally or catalytically cracked hydrocarbons, hydrocracked petroleum fractions, catalytically reformed hydrocarbons, or mixtures thereof.

[0063] The particular distillation curve, hydrocarbon composition, research octane number (RON), and motor octane number (MON) of the gasoline are not critical.

[0064] Conveniently, the research octane number (RON) of the gasoline may be at least 80, such as in the range 80 to 110, preferably the RON of the gasoline is at least 90, such as in the range 90 to 110, more preferably the RON of the gasoline is at least 91, such as in the range 91 to 105, even more preferably the RON of the gasoline is at least 92, such as in the range 92 to 103, even more preferably the RON of the gasoline is at least 93, such as in the range 93 to 102, and most preferably the RON of the gasoline is at least 94, such as in the range 94 to 100 (EN 25164). The motor octane number (MON) of the gasoline may conveniently be at least 70, such as in the range of 70 to 110, preferably the MON of the gasoline is at least 75, such as in the range of 75 to 105, more preferably the MON of the gasoline is at least 80, such as in the range of 80 to 100, and most preferably the MON of the gasoline is at least 82, such as in the range of 82 to 95 (EN 25163).

[0065] Typically, the gasoline comprises components selected from one or more of the groups: saturated, olefinic, aromatic and oxygenated hydrocarbons. Advantageously, the gasoline may comprise a mixture of saturated, olefinic, aromatic and, optionally, oxygenated hydrocarbons.

[0066] Typically, the olefinic hydrocarbon content of the gasoline is in the range of 0 to 40 volume percent based on gasoline (ASTM D1319), preferably, the olefinic hydrocarbon content of the gasoline is in the range of 0 to 30 volume percent based on gasoline, and more preferably, the olefinic hydrocarbon content of the gasoline is in the range of 0 to 20 volume percent based on gasoline.

[0067] Typically, the aromatic hydrocarbon content of the gasoline is in the range of 0 to 70 volume percent based on gasoline (ASTM D1319), for example, the aromatic hydrocarbon content of the gasoline is in the range of 10 to 60 volume percent based on gasoline. Preferably, the aromatic hydrocarbon content of the gasoline is in the range of 0 to 50 volume percent based on gasoline, for example, the aromatic hydrocarbon content of the gasoline is in the range of 10 to 50 volume percent based on gasoline.

[0068] In one embodiment herein, the gasoline base fuel contains less than 10% by volume of aromatics based on the total base fuel. In another embodiment herein, the gasoline base fuel contains less than 2% by volume of aromatics having 9 or more carbon atoms based on the total base fuel.

[0069] The benzene content of the gasoline is at most 10 percent by volume, more preferably at most 5 percent by volume, especially at most 1 percent by volume, based on gasoline.

[0070] The gasoline preferably has a low or ultra-low sulphur content, for example a maximum of 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 10 ppmw or less.

[0071] The gasoline also preferably has a low total lead content, such as a maximum of 0.005 g / l, and is most preferably lead-free, ie no lead compounds are added to the gasoline (ie unleaded).

[0072] When the gasoline contains oxygenated hydrocarbons, at least a portion of the non-oxygenated hydrocarbons are replaced with oxygenated hydrocarbons (match blend) or simply added to the fully blended gasoline (splash blend). The oxygenate content of the gasoline can be up to 85 weight percent (EN 1601) based on the gasoline (e.g., ethanol itself). For example, the oxygenate content of the gasoline can be up to 35 weight percent, preferably up to 25 weight percent, more preferably up to 10 weight percent. Advantageously, the oxygen concentration has a minimum concentration selected from any one of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 weight percent, and a maximum concentration selected from any one of 12, 8, 7.2, 5, 4.5, 4.0, 3.5, 3.0, and 2.7 weight percent.

[0073] Examples of oxygenated hydrocarbons that may be incorporated into gasoline include alcohols, ethers, esters, ketones, aldehydes, carboxylic acids and their derivatives, and oxygen-containing heterocyclic compounds.Preferably, the oxygenated hydrocarbons that may be incorporated into gasoline are selected from alcohols (such as methanol, ethanol, propanol, 2-propanol, butanol, tert-butanol, iso-butanol, and 2-butanol), ethers (preferably ethers containing 5 or more carbon atoms per molecule, such as methyl tert-butyl ether and ethyl tert-butyl ether), and esters (preferably esters containing 5 or more carbon atoms per molecule).A particularly preferred oxygenated hydrocarbon is ethanol.

[0074] If oxygenated hydrocarbons are present in gasoline, the amount of oxygenated hydrocarbons in the gasoline can vary over a wide range. For example, gasoline containing major proportions of oxygenated hydrocarbons, such as ethanol itself and E85, and gasoline containing minor proportions of oxygenated hydrocarbons, such as E10 and E5, are currently commercially available in countries such as Brazil and the United States.

[0075] Thus, the gasoline may contain up to 100 volume percent of oxygenated hydrocarbons. E100 fuels, as used in Brazil, are also included herein. Preferably, the amount of oxygenated hydrocarbons present in the gasoline is selected from one of the following amounts, depending on the desired final formulation of the gasoline: up to 70 volume percent, up to 65 volume percent, up to 30 volume percent, up to 20 volume percent, up to 15 volume percent, and up to 10 volume percent. Advantageously, the gasoline may contain at least 0.5, 1.0, or 2.0 volume percent of oxygenated hydrocarbons.

[0076] Examples of suitable gasolines include those having an olefinic hydrocarbon content of 0 to 20 volume percent (ASTM D1319), an oxygen content of 0 to 5 weight percent (EN 1601), an aromatic hydrocarbon content of 0 to 50 volume percent (ASTM D1319), and a benzene content of up to 1 volume percent.

[0077] Also, biomass or CO 2 Also suitable for use herein are gasoline blending components that may be derived from sources other than crude oil, such as low carbon gasoline fuels from any of the above, as well as blends thereof with each other or with fossil derived gasoline streams and components.

[0078] Suitable examples of such fuels include: 1) Biomass induction a. Straight run bionaphtha from hydrodeoxygenation of biomass; and b. Synthetic wax cracking and / or isomerization products (syngas (CO / H 2 ) to synthetic wax via the FT process), which is then hydrocracked / hydroisomerized to produce a slate of products including fractions in the gasoline distillation range. 2) CO 2 Induction a. CO by modified water / gas shift reaction to synthetic wax by FT process 2 +H 2 Syngas (CO / H2 ) which is then hydrocracked / hydroisomerized to produce a slate of products including fractions in the gasoline distillation range. 3) Methanol induction a. Syngas (CO / H 2 ) to methanol, MTG to gasoline (MTG is the "methanol to gasoline" process). H used in all processes to further reduce the carbon intensity of the fuel. 2 is renewable (environmentally friendly) H2O from the electrolysis of water using renewable electricity from sources such as wind and solar. 2 It would be.

[0079] Gasoline blending components that can be derived from biological sources are particularly suitable for use herein. Examples of such gasoline blending components can be found in WO 2009 / 077606, WO 2010 / 028206, WO 2010 / 000761, European Patent Application Nos. 09160983.4, 09176879.6, 09180904.6, and U.S. Patent Application No. 61 / 312307.

[0080] Although not critical to the present invention, the base gasoline or gasoline composition of the present invention may advantageously contain one or more optional fuel additives in addition to the essential tetraalkylethane compound and essential alkylbenzene compound described above. The concentration and nature of the optional fuel additives that may be included in the base gasoline or gasoline composition of the present invention are not critical. Non-limiting examples of suitable types of fuel additives that may be included in the base gasoline or gasoline composition of the present invention include antioxidants, corrosion inhibitors, detergents, haze removers, anti-knock additives, metal deactivators, valve seat recession inhibitor compounds, dyes, solvents, carrier fluids, diluents, and markers. Examples of suitable such additives are generally described in U.S. Pat. No. 5,855,629.

[0081] Conveniently, the fuel additives can be blended with one or more solvents to form an additive concentrate, and the additive concentrate can then be mixed with the base gasoline or gasoline composition of the present invention.

[0082] The (active matter) concentration of any optional additive present in the base gasoline or gasoline composition of the invention is preferably up to 1 percent by weight, more preferably in the range 5 to 2000 ppmw, advantageously in the range 300 to 1500 ppmw, for example 300 to 1000 ppmw.

[0083] As noted above, the gasoline composition may also contain synthetic or mineral carrier oils and / or solvents.

[0084] Examples of suitable mineral carrier oils are fractions obtained in crude oil processing, such as bright stocks or base oils having a viscosity of the SN 500-2000 class, as well as aromatic hydrocarbons, paraffinic hydrocarbons, and alkoxyalkanols. Fractions obtained in mineral oil refining and known as "hydrocracked oils" (vacuum distillation fractions having a boiling range of about 360-500°C obtained from natural mineral oils that have been catalytically hydrogenated under high pressure, isomerized, and further deparaffinized) are also useful as mineral carrier oils.

[0085] Examples of suitable synthetic carrier oils are polyolefins (poly-alpha-olefins or poly(internal olefins)), (poly)esters, (poly)alkoxylates, polyethers, aliphatic polyetheramines, alkylphenol-started polyethers, alkylphenol-started polyetheramines, and carboxylic acid esters of long chain alkanols.

[0086] Examples of suitable polyolefins are in particular olefin polymers based on polybutene or polyisobutene (hydrogenated or non-hydrogenated).

[0087] Examples of suitable polyethers or polyetheramines are preferably 2 _ c60 -Alkanol, c 6 -c 30 -Alkanediols, mono- or di-c 2 -c 30 -Alkylamines, c 1 -c 30 -Alkylcyclohexanol, or c 1 -c 30 - alkylphenols obtained by reacting 1 to 30 moles of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines; 2 _ c 4 -alkylene moieties. Such products are described, inter alia, in EP-A-310875, EP-A-356725, EP-A-700985 and US-A-4,877,416. For example, the polyetheramines used are poly-c 2 -c 6 -alkylene oxide amines or functional derivatives thereof, typical examples of which are tridecanol butoxylate or isotridecanol butoxylate, isononylphenol butoxylate, and also polyisobutenol butoxylate and polyisobutenol propoxylate, and the corresponding reaction products with ammonia.

[0088] 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, as described in particular in DE-A-3838918. The mono-, di- or tricarboxylic acids used can be aliphatic or aromatic acids, and suitable ester alcohols or polyols are in particular long-chain representatives, for example having 6 to 24 carbon atoms. Typical representatives of esters are the adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and isotridecanol, for example di-(n- or isotridecyl)phthalate.

[0089] Further suitable carrier oil systems are described, for example, in DE-A-3826608, DE-A-4142241, DE-A-4309074, EP-A-0452328 and EP-A-0548617, which are incorporated herein by reference.

[0090] Examples of particularly suitable synthetic carrier oils include, for example, synthetic olefins having about 5 to 35, e.g., about 5 to 30, c units selected from propylene oxide units, n-butylene oxide units, and isobutylene oxide units, or mixtures thereof. 3 -c 6 -alkylene oxide units. Non-limiting examples of suitable starting alcohols are long-chain alkanols or phenols substituted with long-chain alkyl radicals, where the long-chain alkyl radicals are, in particular, linear or branched c 6 -c 18 -g-alkyl radical. Preferred examples include tridecanol and nonylphenol.

[0091] Further suitable synthetic carrier oils are alkoxylated alkylphenols, as described in German Patent Application No. A-10102913.6.

[0092] Mineral carrier oils, synthetic carrier oils, and mixtures of mineral and synthetic carrier oils may also be used.

[0093] Any solvent and optional co-solvent suitable for use in fuels may be used. Examples of solvents suitable for use in fuels include non-polar hydrocarbon solvents such as kerosene, heavy aromatic solvents ("Solvent Naphtha Heavy", "Solvesso 150"), toluene, xylene, paraffin, petroleum, white spirits, and those sold by Shell under the trademark "SHELLSOL". Examples of suitable co-solvents include polar solvents such as esters and, in particular, alcohols (e.g., t-butanol, i-butanol, hexanol, 2-ethylhexanol, 2-propylheptanol, decanol, isotridecanol, butyl glycol, and alcohol mixtures such as those sold by Shell under the trademark "LINEVOL", in particular c 7-9 LINEVOL 79 alcohol, a mixture of primary alcohols, or commercially available c 12-14 alcohol mixtures).

[0094] Dehazers / demulsifiers suitable for use in liquid fuels are well known in the art. Non-limiting examples include glycoloxyalkylate polyol blends (such as those sold under the trade name TOLAD™ 9312), alkoxylated phenol formaldehyde polymers, phenol / formaldehyde or c 1-18 c modified by oxyalkylation with epoxides and diepoxides 1-18 Alkylphenol / -formaldehyde resin oxyalkylates (such as those sold under the trade name TOLAD™ 9308) and crosslinked with diepoxides, diacids, diesters, diols, diacrylates, dimethacrylates, or diisocyanates. 1-4 Epoxide copolymers, as well as blends thereof. Glycoloxyalkylate polyol blends include c 1-4 It may be a polyol oxyalkylated with an epoxide. 1-18c modified by oxyalkylation with epoxides and diepoxides 1-18 The alkylphenol phenol / -formaldehyde resin oxyalkylates may be based, for example, on cresol, t-butylphenol, dodecylphenol, or dinonylphenol, or mixtures of phenols (e.g., a mixture of t-butylphenol and nonylphenol). The dehazer should be used in an amount sufficient to suppress the haze that may result when gasoline without the dehazer comes into contact with water, which amount is referred to herein as a "haze suppressing amount." Generally, this amount is about 0.1 to about 20 ppmw (e.g., about 0.1 to about 10 ppm), more preferably 1 to 15 ppmw, even more preferably 1 to 10 ppmw, and advantageously 1 to 5 ppmw, based on the weight of the gasoline.

[0095] Further conventional additives for use in gasoline are, for example, corrosion inhibitors based on ammonium salts of organic carboxylic acids, which tend to form films, or ammonium salts of heteroaromatic aromatics for non-ferrous metal corrosion protection; antioxidants or stabilizers based on amines, such as phenyldiamines, for example p-phenylenediamine, N,N'-di-sec-butyl-p-phenyldiamine, dicyclohexylamine, or their derivatives, or derivatives of phenols, such as 2,4-di-tert-butylphenol or 3,5-di-tert-butyl-4-hydroxy-phenylpropionic acid; antistatic agents; metallocenes, such as ferrocene; methylcyclopentadienyl manganese tricarbonyl; lubricity additives, such as certain fatty acids, alkenyl succinic acid esters, bis(hydroxyalkyl) fatty amines, hydroxyacetamides, or castor oil; and dyes (markers).If appropriate, amines can also be added, for example as described in WO 03 / 076554. Optionally, an anti-valve seat recession additive such as a sodium or potassium salt of a polymeric organic acid may be used.

[0096] The gasoline compositions herein may also contain detergent additives. Suitable detergent additives include those disclosed in WO 2009 / 50287, which is incorporated herein by reference.

[0097] Preferred detergent additives for use in the gasoline compositions herein typically comprise at least one hydrophobic hydrocarbon radical having a number average molecular weight (Mn) of from 85 to 20,000; (A1) a mono- or polyamino group having up to six nitrogen atoms, at least one of which is basic; (A6) Polyoxy-c terminated with a hydroxyl group, a mono- or polyamino group in which at least one nitrogen atom has basic properties, or a carbamate group. 2 -~-c 4 - an alkylene group, (A8) a moiety derived from succinic anhydride and having a hydroxyl group and / or an amino group and / or an amide group and / or an imide group, and / or (A9) has a substituted phenol and at least one polar moiety selected from moieties obtained by the Mannich reaction of an aldehyde and a mono- or polyamine.

[0098] The hydrophobic hydrocarbon radical in said detergent additive, which ensures adequate solubility in the base fluid, has a number average molecular weight (Mn) of 85-20,000, in particular 113-10,000, in particular 300-5,000.

[0099] Typical hydrophobic hydrocarbon radicals, particularly those associated with the polar moieties (A1), (A8), and (A9), include polyalkenes (polyolefins), such as polypropenyl, polybutenyl, and polyisobutenyl radicals, each having an Mn of 300 to 5000, preferably 500 to 2500, more preferably 700 to 2300, and especially 700 to 1000.

[0100] Non-limiting examples of the above group of detergent additives include the following:

[0101] The additives containing mono- or polyamino groups (A1) are preferably polyalkene monoamines or polyalkene polyamines based on polypropenes having Mn of 300 to 5000 or conventional (i.e. mainly with internal double bonds) polybutenes or polyisobutenes. If polybutenes or polyisobutenes having mainly internal double bonds (usually beta and gamma positions) are used as starting materials in the preparation of the additives, possible preparation routes are by chlorination and subsequent amination or by oxidation of the double bonds with air or ozone to form carbonyl or carboxyl compounds and subsequent amination under reducing (hydrogenation) conditions. The amines used here for the amination can be, for example, ammonia, monoamines, or polyamines, such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, or tetraethylenepentamine. Corresponding additives based on polypropene are described, in particular, in WO-A-94 / 24231.

[0102] Further preferred additives containing monoamino groups (A1) are the hydrogenation products of the reaction products of polyisobutenes having an average degree of polymerization between 5 and 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular in WO-A-97 / 03946.

[0103] Further preferred additives containing monoamino groups (A1) are compounds which are obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as described in particular in DE-A-19620262.

[0104] Polyoxy-c 2 -c 4 The additive comprising an alkylene moiety (A6) is preferably 2 -~c 60 -Alkanol, c 6 -~c 30 -Alkanediols, mono- or di-c 2 -c 30 -Alkylamines, c1 -c 30 -Alkylcyclohexanol, or c 1 -c 30 -Polyethers or polyetheramines obtained by reaction of alkylphenols with 1 to 30 moles of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines. Such products are described, in particular, in EP-A-310875, EP-A-356725, EP-A-700985 and US-A-4877416. In the case of polyethers, such products also have carrier oil properties. Typical examples of these are tridecanol butoxylates, isotridecanol butoxylates, isononylphenol butoxylates and polyisobutenol butoxylates and polyisobutenol propoxylates and the corresponding reaction products with ammonia.

[0105] The additives containing moieties (A8) derived from succinic anhydride and carrying hydroxyl and / or amino and / or amide and / or imide groups are preferably the corresponding derivatives of polyisobutenyl succinic anhydride obtained by reacting conventional polyisobutenes or highly reactive polyisobutenes having Mn between 300 and 5000 with maleic anhydride by the thermal route or via chlorinated polyisobutene. Of particular interest are derivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine. Such additives are described, inter alia, in US Pat. No. 4,849,572.

[0106] The additives containing moieties (A9) obtained by the Mannich reaction of substituted phenols with aldehydes and mono- or polyamines are preferably reaction products of polyisobutenyl-substituted phenols with formaldehyde and mono- or polyamines, such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, or dimethylaminopropylamine. The polyisobutenyl-substituted phenols can be derived from conventional polyisobutenes or highly reactive polyisobutenes having Mn between 300 and 5000. Such "polyisobutene-Mannich bases" are described, inter alia, in EP-A-831141.

[0107] Preferably, the detergent additive used in the gasoline composition of the present invention contains at least one nitrogen-containing detergent, more preferably at least one nitrogen-containing detergent containing a hydrophobic hydrocarbon radical having a number average molecular weight in the range of 300 to 5000. Preferably, the nitrogen-containing detergent is selected from the group comprising polyalkene monoamines, polyetheramines, polyalkene Mannich amines, and polyalkene succinimides. Conveniently, the nitrogen-containing detergent may be a polyalkene monoamine.

[0108] In the above, the amounts of ingredients (concentrations, volume %, ppmw, weight %) are of the active substance, i.e. excluding volatile solvent / diluent materials.

[0109] In the liquid fuel composition of the present invention, when the base fuel used is a diesel fuel, the diesel fuel used as the base fuel in the present invention includes diesel fuels for use in automotive compression ignition engines, as well as for use in other types of engines, such as off-road, marine, rail, and stationary engines. For convenience, the diesel fuel used as the base fuel in the liquid fuel composition of the present invention may also be referred to as a "diesel base fuel".

[0110] The diesel base fuel may itself comprise a mixture of two or more different diesel fuel components and / or may be additived as described below.

[0111] Such diesel fuels typically contain one or more base fuels which may include liquid hydrocarbon middle distillate gas oils, e.g. petroleum derived gas oils. Such fuels typically have boiling points within the normal diesel range of 150-400°C, depending on grade and use. Such fuels typically have a boiling point of 750-1000 kg / m at 15°C. 3 , preferably 780 to 860 kg / m 3 (e.g. ASTM D4502 or IP 365) and a cetane number (ASTM D613) of 35 to 120, more preferably 40 to 85. Such fuels typically have an initial boiling point in the range of 150 to 230°C and a final boiling point in the range of 290 to 400°C. The kinematic viscosity (ASTM D445) of such fuels at 40°C is suitably 1.2 to 4.5 mm 2 / s.

[0112] An example of a petroleum derived gas oil is Swedish Class 1 base fuel, which has a thermal conductivity of 800-820 kg / m at 15°C as defined by the Swedish national specification EC1. 3 Density (SS-EN ISO 3675, SS-EN ISO 12185), T95 below 320°C (SS-EN ISO 3405), and 1.4 to 4.0 mm 2 / s at 40 °C (SS-EN ISO 3104).

[0113] Also, biomass or CO 2 Also suitable for use herein are diesel blend components that may be derived from sources other than crude oil, such as low carbon diesel fuels from any of the above-listed fuels, as well as blends thereof with each other or with fossil-derived diesel streams and components.

[0114] Suitable examples of such fuels include: 1) Biomass induction a. Straight-run diesel from hydrodeoxygenation of biomass; and b. Synthetic wax cracking and / or isomerization products (syngas (CO / H 2 ) to synthetic wax via the FT process), which is then hydrocracked / hydroisomerized to produce a slate of products including fractions in the diesel distillation range. 2) CO 2 Induction a. CO by modified water / gas shift reaction to synthetic wax by FT process 2 +H 2 Syngas (CO / H 2 ) which is then hydrocracked / hydroisomerized to produce a slate of products including fractions in the diesel distillation range. 3) Methanol induction a. Syngas (CO / H 2 ) to methanol, MTD (MTD is the "methanol to diesel" process). H used in all processes to further reduce the carbon intensity of the fuel. 2 is renewable (environmentally friendly) H2O from the electrolysis of water using renewable electricity from sources such as wind and solar. 2 It would be.

[0115] Fischer-Tropsch fuels may be derived, for example, from natural gas, liquefied natural gas, petroleum or shale oil, petroleum or shale oil processing residues, coal, or biomass.

[0116] The amount of Fischer-Tropsch derived fuel used in the diesel fuel may be from 0% to 100% by volume, preferably from 5% to 100% by volume, more preferably from 5% to 75% by volume of the total diesel fuel. It may be desirable for such diesel fuel to contain 10% by volume or more, more preferably 20% by volume or more, even more preferably 30% by volume or more of a Fischer-Tropsch derived fuel. It is particularly preferred for such diesel fuel to contain 30 to 75% by volume, especially 30 to 70% by volume of a Fischer-Tropsch derived fuel. The balance of the diesel fuel is made up of one or more other diesel fuel components.

[0117] Such a Fischer-Tropsch derived fuel component is any fraction in the middle distillate fuel range, which can be isolated from the (optionally hydrocracked) Fischer-Tropsch synthesis product. Typical fractions boil in the naphtha, kerosene, or gas oil range. Preferably, a Fischer-Tropsch product boiling in the kerosene or gas oil range is used, as these products are easier to handle, for example in a domestic environment. Such a product suitably comprises more than 90 wt. % of a fraction boiling between 160 and 400°C, preferably up to about 370°C. Examples of Fischer-Tropsch derived kerosenes and gas oils are described in EP-A-0583836, WO-A-97 / 14768, WO-A-97 / 14769, WO-A-00 / 11116, WO-A-00 / 11117, WO-A-01 / 83406, WO-A-01 / 83648, WO-A-01 / 83647, WO-A-01 / 83641, WO-A-00 / 20535, WO-A-00 / 20534, EP-A-1101813, U.S. Pat. No. 5766274, U.S. Pat. No. 5378348, U.S. Pat. No. 5888376, and U.S. Pat. No. 6204426.

[0118] The Fischer-Tropsch product preferably contains more than 80 wt.%, and more preferably more than 95 wt.%, iso- and normal paraffins and less than 1 wt.% aromatics, the remainder being naphthenic compounds. The sulfur and nitrogen contents are very low, usually below the detection limits of such compounds. For this reason, the sulfur content of diesel fuel compositions containing the Fischer-Tropsch product can be very low.

[0119] Diesel fuel compositions preferably contain no more than 5000 ppmw sulfur, more preferably no more than 500 ppmw, or no more than 350 ppmw, or no more than 150 ppmw, or no more than 100 ppmw, or no more than 70 ppmw, or no more than 50 ppmw, or no more than 30 ppmw, or no more than 20 ppmw, or most preferably no more than 10 ppmw sulfur.

[0120] Other diesel fuel components for use herein include so-called "biofuels" derived from biological materials. Examples include fatty acid alkyl esters (FAAEs). Examples of such components can be found in WO 2008 / 135602. Fully hydrogenated FAAEs are also available and are referred to as "renewable diesel". Biofuels can be derived from animal or vegetable oils.

[0121] Renewable diesel fuel from solid biomass and bio-oil, such as that disclosed in U.S. Patent Application Publication No. 2013 / 0008081(A1), may be used herein.

[0122] The diesel base fuel may itself be additivated (additivated) or unadditivated (additivated). If it is additivated, for example at the refinery, it will contain minor amounts of one or more additives selected from, for example, antistatic agents, pipeline drag reducers, flow improvers (e.g. ethylene / vinyl acetate copolymers or acrylates / maleic anhydride copolymers), lubricity additives, antioxidants, and wax anti-settling agents.

[0123] Detergent-containing diesel fuel additives are known and commercially available. Such additives may be added to diesel fuel at levels intended to reduce, remove, or retard the build-up of engine deposits.

[0124] Examples of detergents suitable for use in diesel fuel additives for this purpose include polyolefin-substituted succinimides or polyamine succinamides, such as polyisobutylene succinimides or polyisobutylene amine succinamides, aliphatic amines, Mannich bases or amines, and polyolefin (e.g. polyisobutylene) maleic anhydride.Succinimide dispersant additives are described, for example, in GB-A-960493, EP-A-0147240, EP-A-0482253, EP-A-0613938, EP-A-0557516, and WO-A-98 / 42808.Particularly preferred are polyolefin-substituted succinimides, such as polyisobutylene succinimides.

[0125] Diesel fuel additive mixtures may contain other components in addition to detergents. Examples include lubricity improvers; dehazers, such as alkoxylated phenol formaldehyde polymers; antifoam agents (e.g., polyether modified polysiloxanes); ignition improvers (cetane improvers) (e.g., 2-ethylhexyl nitrate, 2-ethylhexyl ether, 2-methyl-2-propanediol ... nitrate (EHN), cyclohexyl nitrate, di-tert-butyl peroxide, and those disclosed in US-A-4208190, column 2, line 27 to column 3, line 21); rust inhibitors (e.g., propane-1,2-diol half esters of tetrapropenyl succinic acid, or polyhydric alcohol esters of succinic acid derivatives, which have on at least one of their alpha-carbon atoms an unsubstituted or substituted aliphatic hydrocarbon group containing from 20 to 500 carbon atoms, e.g., pentaerythritol diesters of polyisobutylene-substituted succinic acids); corrosion inhibitors; fragrances; antiwear additives; antioxidants (e.g., phenols such as 2,6-di-tert-butylphenol, or phenylenediamines such as N,N'-di-sec-butyl-p-phenylenediamine); metal deactivators; combustion improvers; static electricity dissipation additives; low-temperature flow improvers; and wax antisettling agents.

[0126] The diesel fuel additive mixture may contain a lubricity improver, particularly when the diesel fuel composition has a low (e.g., 500 ppmw or less) sulphur content. In the additivated diesel fuel composition, the lubricity improver is conveniently present in a concentration of less than 1000 ppmw, preferably from 50 to 1000 ppmw, more preferably from 70 to 1000 ppmw. Suitable commercially available lubricity improvers include ester-based and acid-based additives. Other lubricity improvers are described in the patent literature, particularly in relation to their use in low sulphur content diesel fuels, for example in: -Paper by Danping Wei and HASpikes, "The Lubricity of Diesel Fuels", Wear, III (1986) 217-235; -WO-A-95 / 33805 - Low temperature flow improvers for improving the lubricity of low sulphur fuels; - U.S. Pat. No. 5,490,864 - Certain dithiophosphate diester-dialcohols as antiwear and lubricity additives in low sulfur diesel fuels; and - WO-A-98 / 01516 - Certain alkylaromatic compounds having at least one carboxyl group attached to their aromatic nucleus for imparting an anti-wear lubricating effect, particularly in low sulfur diesel fuels.

[0127] It may also be preferred that the diesel fuel composition contains an antifoam agent, more preferably in combination with a rust and / or corrosion inhibitor and / or a lubricity improving additive.

[0128] Unless otherwise stated, the (active matter) concentration of each such optional additive component in the additivated diesel fuel composition is preferably in the range up to 10000 ppmw, more preferably from 0.1 to 1000 ppmw, advantageously from 0.1 to 300 ppmw, for example from 0.1 to 150 ppmw.

[0129] The (active matter) concentration of any dehazer in the diesel fuel composition is preferably in the range 0.1 to 20 ppmw, more preferably 1 to 15 ppmw, even more preferably 1 to 10 ppmw, especially 1 to 5 ppmw. The (active matter) concentration of any ignition improver present is preferably not more than 2600 ppmw, more preferably not more than 2000 ppmw, even more preferably 300 to 1500 ppmw. The (active matter) concentration of any detergent in the diesel fuel composition is preferably in the range 5 to 1500 ppmw, more preferably 10 to 750 ppmw, most preferably 20 to 500 ppmw.

[0130] In the case of diesel fuel compositions, for example, the fuel additive mixture typically contains a detergent and a diesel fuel compatible diluent, optionally along with other components as described above, which may be mineral oils, solvents such as those sold by Shell under the trade name "SHELLSOL", polar solvents such as esters, especially alcohols, e.g., hexanol, 2-ethylhexanol, decanol, isotridecanol, and alcohol mixtures such as those sold by Shell under the trademark "LINEVOL", especially c 7-9 LINEVOL 79 alcohol, a mixture of primary alcohols, or commercially available c 12-14 It may be a mixture of alcohols.

[0131] The total content of additives in the diesel fuel composition may suitably be from 0 to 10000 ppmw, and preferably less than 5000 ppmw.

[0132] In the above, the amounts of ingredients (concentrations, volume %, ppmw, weight %) are of the active substance, i.e. excluding volatile solvent / diluent materials.

[0133] The liquid fuel composition of the present invention can be produced by blending the requisite tetraalkylethane and alkylbenzene compounds with a base fuel suitable for use in an internal combustion engine. Because the base fuel into which the requisite fuel additive is blended is gasoline, the liquid fuel composition produced is a gasoline composition. Similarly, when the base fuel into which the additive is blended is diesel fuel, the liquid fuel composition produced is a diesel fuel composition.

[0134] Surprisingly, it has been found that the use of the combinations of tetraalkylethane compounds and alkylbenzene compounds described herein in liquid fuel compositions provides benefits in terms of improved power, improved acceleration, reduced burn duration, increased flame speed, and improved fuel economy of internal combustion engines fueled with liquid fuel compositions containing the tetraalkylethane compounds and the alkylbenzene compounds as compared to internal combustion engines fueled with liquid base fuels.

[0135] The present invention will be further understood from the following examples. Unless otherwise specified, all amounts and concentrations disclosed in the examples are based on the weight of the fully formulated fuel composition.

[0136] Working Example The goal of these experiments was to screen a series of additives for potential combustion enhancing properties using a gasoline single cylinder engine (GSCE). Combustion improvement can be demonstrated essentially in two modes: pre-ignition retard (important for reducing knock at high compression ratios, octane boost) or flame speed improver (reducing burn duration and improving power).

[0137] A number of fully formulated fuel compositions are provided below (Examples 1-4).

[0138] All fuel compositions use the same base fuel, which is E10 fuel (containing 10% ethanol) conforming to the North American main grade specification ASTM D4814 without performance additives.

[0139] 1,3,5-trimethylbenzene (TMB) and / or dicumene were added to the base fuel at the treat rates shown below in Table 1, which also shows the RON and MON values ​​for each fuel blend.

[0140] [Table 1]

[0141] Test conditions The engine used for these experiments was a gasoline single cylinder engine. The engine was manufactured by AVL and was based on the EA888 2.0L Audi TFSI / VW TSI (Euro 6). The details of the single cylinder bench engine are shown in Table 2 below.

[0142] [Table 2]

[0143] The engine test conditions are detailed in Table 3 below.

[0144] [Table 3]

[0145] The following test protocol was run using the base fuel and one test fuel (one of Examples 1-4) per day. Warm up the engine and line out on base fuel · Run baseline spark sweeps: 1300ML, HL, 3300ML (ML=Medium Load; HL=High Load) Switch to test fuel and flush 30 litres Test: Spark sweep at three different conditions (1300 rpm, IMEP: 11.5 bar and 8 bar; and 3300 rpm, IMEP: 12.4 bar). ·end.

[0146] Each test fuel blend was screened twice, once in each of two randomized loops (Example 2 was tested once).

[0147] P max, burn duration, and exhaust temperature measurements were made and the results are shown below in Tables 4, 5, 6, and 7. Table 4 shows the average % difference in Pmax between the test blends and their base fuel controls at 1300HL, IGN=1 (IGN=ignition time).

[0148] FIG. 1 is a graphical representation of the experimental data set forth in Table 4 for Examples 1-4 (Example number is on the x-axis and the average % difference in Pmax is on the y-axis). Table 5 shows the % difference analysis of burn duration between the test blends at 1300HL, IGN=1 and their base fuel control. FIG. 2 is a graphical representation of the experimental data set forth in Table 5 for Examples 1-4 (Example number is on the x-axis and the % difference in burn duration is on the y-axis). Table 6 shows the exhaust temperature for each test fuel and the % difference in exhaust temperature between the test blends and their base fuel control (1300HL, IGN=1). FIG. 3 is a graphical representation of the experimental data set forth in Table 6 for Examples 1-4 (Example number is on the x-axis and the average % difference in exhaust temperature is on the y-axis). Table 7 shows the average % difference (AI50-90) of burn duration between the test blends at 1300HL, IGN=1 and their base fuel control. FIG. 4 is a graphical representation of the experimental data set forth in Table 7 for Examples 1-4 (Example number is on the x-axis and mean % difference in burn duration (AI 50-90%) is on the y-axis).

[0149] [Table 4]

[0150] [Table 5]

[0151] [Table 6]

[0152] [Table 7]

[0153] Consideration The use of the dicumene / TMB combination in the gasoline fuel composition of the present invention has been shown to reduce combustion duration and P max It has been shown that the fuel compositions of the present invention provide an increase in exhaust gas temperature. A reduction in exhaust gas temperature was also observed with the fuel compositions of the present invention, which indicates improved fuel economy. The magnitude of these results is particularly surprising, especially considering the very low levels of dicumene / TMB additive concentration that were used.

Claims

1. A fuel composition, (a) A base fuel suitable for use in an internal combustion engine, (b) A tetraalkylethane compound having formula (I), 【Chemistry 1】 In the formula, Ar is an unsubstituted phenyl group, and each X is independently a hydrogen atom or an unsubstituted linear or branched saturated carbon atom. １ - Selected from C3 alkyl groups, however each CX ３ A tetraalkylethane compound in which at least one of the X groups in the group is a hydrogen atom, (c) A fuel composition comprising an alkylbenzene compound which is a trimethylbenzene compound.

2. The fuel composition according to claim 1, wherein the alkylbenzene compound is 1,3,5-trimethylbenzene.

3. The fuel composition according to claim 1 or 2, wherein the tetraalkylethane compound is 1,1'(1,1,2,2-tetramethyl-1,1-ethanediyl)bis-benzene.

4. A method for improving the output of an internal combustion engine, wherein the method comprises supplying the engine with a fuel composition according to claim 1 or 2.

5. A method for improving the acceleration of an internal combustion engine, wherein the method comprises supplying the engine with a fuel composition according to claim 1 or 2.

6. A method for shortening the combustion duration of a fuel composition in an internal combustion engine, wherein the method comprises supplying the liquid fuel composition described in claim 1 or 2 to the internal combustion engine.

7. A method for increasing the flame rate of a fuel composition in an internal combustion engine, the method comprising supplying the liquid fuel composition according to claim 1 or 2 to the internal combustion engine.

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