GB2466713A

GB2466713A - Gasoline compositions

Info

Publication number: GB2466713A
Application number: GB0922616A
Authority: GB
Inventors: Allison Felix-Moore; Jurgen Johannes Jacobus Louis; Johanne Smith
Original assignee: Shell Internationale Research Maatschappij BV
Current assignee: Shell Internationale Research Maatschappij BV
Priority date: 2008-12-31
Filing date: 2009-12-23
Publication date: 2010-07-07
Also published as: GB0922616D0

Abstract

A gasoline composition comprising(i) an unleaded gasoline base fuel,(ii) from 1 to 30 vol.%, based on the overall gasoline composition, of component A, wherein component A is selected from compounds of formula I: wherein the R3, R4, R5 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups; and(iii) one or more fuel additives selected from phenolic antioxidants, aminic antioxidants, corrosion inhibitors and mixtures thereof. The gasoline composition of the present invention exhibits excellent lubricity.

Description

GASOLINE COMPOSITIONS

Field of the Invention

The present invention relates to gasoline compositions, and in particular to gasoline compositions having improved lubricity.

Background of the Invention

Various furan derivatives such as 2-methyl furan and 2,5-dimethyl furan are known for use as blending components in gasoline.

For instance, EP-A--O,082,689 (BP) discloses a fuel composition for use in spark ignition internal combustion engines comprising a high octane gasoline and an alkyl furan having a boiling point of not more than l50C.

Suitable alkyl furans disclosed therein are 2-methyl furari and 2,5-dimethyl furan. The gasoline may be leaded or unleaded.

QS-A--2,32l,3l1 discloses a motor fuel composition comprising a mixture of gasoline hydrocarbons adapted as a base fuel for spark-ignition engines improved in anti-knock value by an addition of a substantial amount of at least 1% by volume of a heterocyclic compound containing a furane nucleus and selected from the group consisting of furane, alkyl furans, furfuryl alcohols, furfuryl amines, and the saturated derivatives thereof, said heterocyclic compound boiling in the range of said base fuel. 2-methyl furan and 2,5-dimethyl furan are specifically mentioned.

tJS-A-5,354,344 discloses a fuel oil composition for use in a spark ignition engine, which comprises gasoline for spark ignition engine use and an oxygen-containing organic compound. The oxygen-containing organic compound can be furan or a specified furan derivative (having formula IV therein). Examples of compounds of the formula IV include furan, 2-methyl furan and furfural.

GB-A-802181 discloses a fuel composition comprising an aliphatic oxygen compound and a gasoline blend. Furan and its derivatives and hydrogenated furan and its derivatives are mentioned as suitable aliphatic oxygen compounds.

Additives such as anti-oxidants and corrosion inhibitors are known for use in fuel compositions for improving the performance of the fuel. Due to ever increasing demands for higher performing fuels, it would be desirable to provide gasoline compositions having increased lubricity properties. It has now surprisingly been found that by combining a specified furan derivative with a specified additive in a gasoline composition improvements in the lubricity of the gasoline composition are observed.

Summary of the Invention

According to the present invention there is provided a gasoline composition comprising Ci) an unleaded gasoline base fuel, (ii) from 1 to 30 vol.%, based on the overall gasoline composition, of component A, wherein component A is selected from compounds of formula I: wherein the R3, R4, R5 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups, and (iii) one or more fuel additives selected from phenolic antioxidants, aminic antioxidants, corrosion inhibitors, and mixtures thereof.

According to the present invention there is further provided the use of from 1 to 30 vol% component A in a gasoline co!uposition comprising a major portion of a gasoline base fuel wherein component A is selected from compounds of formula I: R3 R5 6 R (I) wherein the R3, R4, R5 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups, for improving the lubricity of the gasoline composition.

According to the present invention there is further provided a method of operating an internal combustion engine, typically a spark-ignition internal combustion engine, which method involves introducing into a combustion chamber of the engine a gasoline composition as described herein.

Detailed Description of the Invention

The gasoline composition herein comprises component A selected from a compound or mixture of compounds having formula I: <I) wherein the R3, R4, R5 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups.

Preferably, at least one of the R3, R4, R5 and R6 groups are independently selected from a C1_6 hydrocarbyl groups. More preferably, one or two of the R3, R4, 5 and R6 groups are independently selected from C1_6 hydrdcarbyl groups, with the remaining R3, R4, R5 and R6 groups being hydrogen. Even more preferably, the R4 and R5 groups are hydrogen and the R3 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups, with at least one of the R3 and R6 groups being a C1_6 hydrocarbyl group.

Preferably, the C1_6 hydrocarbyl groups are Cl_6 alkyl groups, more preferably methyl, ethyl and propyl groups.

Component A preferably has a boiling point or boiling point range of at most 210°C, more preferably at most 160°C, more preferably at most 110°C. Typically, the boiling point or boiling point range of component A is within the range of from 40 to 210°C, more typically within the temperature range of from 50 to 160°C, most typically within the temperature range of from 60 to 110°C.

Examples of suitable compounds according to formula I include 2-methyl furan, 3-methyl furan, 2-ethyl furan, 3-ethyl furan, 2,5-dimethyl furan, 2,5-diethyl furan and 2-raethyl--5-ethyl furan, and mixtures thereof.

Most preferably component A is selected from 2-methyl furan, 2,5-dirnethyl furan and mixtures thereof, especially 2-methyl furan.

Component A can be derived from a biological source using methods known in the art and therefore can be included in a gasoline composition as a biofuel component.

The gasoline composition according to the present invention may be prepared by blending the base gasoline with component A. The base gasoline used in the compositions herein may be any gasoline suitable for use in an internal combustion engine of the spark-ignition (petrol) type known in the art.

The base gasoline typically comprises mixtures of hydrocarbons boiling in the range from 25 to 230°C (EN-Iso 3405), the optimal ranges and distillation curves typically varying according to climate and season of the year. The hydrocarbons in a gasoline base fuel 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, hydro-cracked petroleum fractions, catalytically reformed hydrocarbons or mixtures of these.

The specific distillation curve, hydrocarbon composition, research octane number (RON) and motor octane number (MON) of the gasoline base fuel are not critical.

Conveniently, the research octane number (RON) of the gasoline base fuel may be in the range of from 80 to 110, preferably from 90 to 105, more preferably from 93 to 102, most preferably from 94 to 100 (EN 5164); the motor octane number (MON) of the gasoline base fuel may suitably be in the range of from 70 to 110, preferably from 75 to 105, more preferably from 80 to 100, most preferably from 84 to 95 (EN 25163).

Typically, gasoline base fuels comprise components selected from one or more of the following groups saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and oxygenated hydrocarbons. Conveniently, the gasoline base fuel may comprise a mixture of saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and, optionally, oxygenated hydrocarbons.

Typically, the olefinic hydrocarbon content of the gasoline base fuel is in the range of from 0 to 40 percent by volume based on the gasoline base fuel; preferably, the olefinic hydrocarbon content of the gasoline base fuel is in the range of from 0 to 30 percent by volume based on the gasoline base fuel.

Typically, the aromatic hydrocarbon content of the gasoline base fuel is in the range of from 0 to 70 percent by volume based on the gasoline base fuel; preferably, the aromatic hydrocarbon content of the gasoline base fuel is in the range of from 10 to 60 percent by volume based on the gasoline base fuel.

The berizene content of the gasoline base fuel is at most 10 percent by volume, more preferably at most 5 percent by volume, especially at most 1 percent by volume based on the gasoline base fuel.

Typically, the saturated hydrocarbon content of the gasoline base fuel is at least 40 percent by volume based on the gasoline base fuel; preferably, the saturated hydrocarbon content of the gasoline base fuel is in the range of from 40 to 80 percent by volume based on the gasoline base fuel.

The gasoline base fuel preferably has a low or ultra low sulphur content. Typically the gasoline composition has a sulphur content of at most 1000 ppmw (parts per million by weight), preferably no more than 500 ppmw, more preferably no more than 100, even more preferably no more than 50 and most preferably no more than even 10 ppmw, relative to the weight of the gasoline composition.

The gasoline base fuel also preferably has a low total lead content, such as at most 0.005 gIl, most preferably being lead free -having no lead compounds added thereto (i.e. unleaded).

When the gasoline comprises oxygenated hydrocarbons, at least a portion of non-oxygenated hydrocarbons will be substituted for oxygenated hydrocarbons.

The oxygenated hydrocarbons that may be included in the gasoline base fuel are oxygenated components other than those of component A described herein.

Examples of suitable gasoline base fuels include gasoline base fuels which have an olefinic hydrocarbon content of from 0 to 20 percent by volume (ASTM D1319), an oxygen content of from 0 to 5 percent by weight (EN 1601), an aromatic hydrocarbon content of from 0 to 50 percent by volume (ASTM D1319) and a benzene content of at most 1 percent by volume.

The gasoline composition of the present invention also comprises one or more fuel additives selected from aminic antioxidants, phenolic antioxidants, corrosion inhibitors and mixtures thereof. The total concentration of the antioxidants, including aminic antioxidants, phenolic antioxidants and mixtures thereof, is preferably in the range of from 100 to 10,000 ppinw, more preferably in the range of from 1000 to 5000 ppmw, relative to the total weight of component A in the gasoline composition.

The concentration of corrosion inhibitor is preferably in the range of from 10 to 1000 ppmw, more preferably in the range of from 100 to 500 ppmw, relative to the total weight of component A in the gasoline composition.

The total level of the one or more fuel additives is preferably in the range of from S to 2000 ppmw, more preferably in the range of from 10 to 1000 ppmw relative to the total weight of the gasoline composition.

In one embodiment of the present invention, the gasoline composition comprises one or more aminic antioxidants. In another embodiment of the present invention, the gasoline composition comprises one or more phenolic antioxidants. In another embodiment of the present invention, the gasoline composition comprises a mixture of at least one aminic antioxidant and at least one pheriolic antioxidant. In a preferred embodiment, the gasoline composition comprises at least one antioxidant and at least one corrosion inhibitor. In another preferred embodiment, the gasoline composition comprises at least one phenolic antioxidant and at least one corrosion inhibitor. In another preferred embodiment, the gasoline composition comprises at least one aminic antioxidant and at least one corrosion inhibitor. In yet another preferred embodiment, the gasoline composition comprises at least one aminic antioxidant, at least one phenolic antioxidant and at least one corrosion inhibitor.

The amiriic antioxidants for use herein may be any aminic antioxidant suitable for use in a gasoline composition. Preferred arninic antioxidarits for use herein include phenylenediamines such as N,N'-di- isopropyl-para-phenylenediarnine and N,N' -di-sec-butyl-para-phenylenediarnine.

A preferred aminic antioxidant includes that available under the trade designation AO-22, commercially available from Innospec.

The phenolic antioxidants for use herein may be any phenolic antioxidants suitable for use in a gasoline composition. Preferred phenolic antioxidants for use herein include 2,6-di-t-butyl-4-alkylphenolS such as 2,6-di-t-butylphenol, 2, 6-di-t.-butyl-4-methylpheflOl (also known as BHT), 2,4-dimethyl-6-t-butylpheflol and 4-methyl- 2, 6-di-t-butyl-phenol.

A preferred phenolic antioxidant for use herein includes the antioxidant commercially available under the trade designation BHT from Sigma Aldrich.

A preferred mixed phenolic and aminic antioxidant includes the antioxidant commercially available under the trade designation DGS 109 from Innospec.

The corrosion inhibitors for use herein may be any corrosion inhibitor suitable for use in a gasoline composition. Compounds such as alkenyl succinic acid or ester moieties thereof, benzotriazole-based compounds and thiadiazole-based compounds, alkyl benzenes such as ethyl benzene and trimethylbenzene, and di-alkylcyclohexylarnines such as N, N-dirnethylcyclohexylamine may be used herein as corrosion inhibitors.

Examples of suitable corrosion inhibitors include those corrosion inhibitors commercially available under the following trade designations: DCI-ll commercially available from Innospec, DCI-4A commercially available from Innospec, HiTec 580 commercially available from Afton, Nalco 5403 commercially available from Nalco, Nalco 5405 commercially available from Nalco, PRI-19 commercially available from Apoilo Technologies International Corp., Spec-Aid 8Q22 commercially available from GE Betz, Tolad 351 commercially available from Baker Petrolite, Unicor J commercially available from Dorf Ketal, Betz AN933 commercially available from GE Betz, Lubrizol 541 commercially available from Lubrizol, Nalco EC5407A commercially available from Nalco, Spec-Aid 8Ql03 commercially available from GE Betz, Tolad 249 -10 -commercially available from Baker Petrolite, Tolad 9715 commercially available from Baker Petrolite, Tolad 9719 commercially available from Baker Petrolite, Unichem 7501 commercially available from BJ Chemical Services, tinichem 7504 commercially available from BJ Chemicals, Unicor commercially available from Dorf Ketal and Unicor PL commercially available from Dorf Ketal.

A preferred corrosion inhibitor for use herein is DCI-ll commercially available from Innospec.

The gasoline composition of the present invention preferably comprises a detergent. Detergents for use herein may be any detergent suitable for use in a gasoline composition. Preferred detergents for use herein are polyisobutyleneamine detergents.

whilst not critical to the present invention, the gasoline compositions of the present invention may conveniently additionally include one or more additional fuel additive(s) other than the one or more fuel additives mentioned above. The concentration and nature of the fuel additive(s) that may be included in the gasoline composition of the present invention is not critical. Non-limiting examples of suitable types of fuel additives that can be included in the gasoline composition of the present invention include anti-oxidants, corrosion inhibitors, detergents, dehazers, antiknock additives, metal deactivators, valve-seat recession protectant compounds, dyes, friction modifiers, carrier fluids, diluents and markers. Examples of suitable such additives are described generally in US Patent No. 5,855,629.

Conveniently, the fuel additives can be blended with one or more diluerits or carrier fluids, to form an additive concentrate, the additive concentrate can then -11 -be admixed with the gasoline composition or gasoline base fuel.

A gasoline composition according to the present invention may be prepared by a process which comprises bringing into admixture with the base gasoline, component A and the one or more fuel additives.

The gasoline compositions of the present invention exhibit excellent lubricity. In particular, it is preferred that the gasoline compositions herein have a High Frequency Reciprocating Rig (HFRR) Lubricity Wear Scar as measured using the HFRR Lubricity Wear Scar Test Method described hereinbelow of less than 800 microns, more preferably less than 700 microns, even more preferably less than 600 microns, and especially less than 500 microns.

The present invention also provides a method of operating a internal combustion engine, typically a spark-ignition internal combustion engine, which comprises bringing into the combustion chambers of said engine a gasoline composition as described herein.

The present invention will be further understood from the following examples. Unless otherwise indicated, parts and percentages (concentration) are by volume (%v/v) and temperatures are in degrees Celsius (°C).

Exaples The base gasoline used in the examples was an EN 228 unleaded gasoline having the specific properties detailed

in Table 1 below:

-12 -

Table 1

Property RON 95.1 MON. 85.4 Density (kg/rn3) 738.5 FBP (°C) -203.6 Residue (%v) 1.0 �70 (%v) 26.9 �100 (%v) 47.8 �150 (%v) 86.5 Sulphur content (ppmw/w) as 21 measured by ISO 20884 Blended gasolines were prepared by adding additive to base gasoline fuel at ambient temperature (20°C) and homogenising.

The following additives were used:- 2-Methyl Furan (ex Sigma Aldrich, purity 99%); "AO-22" -this is an aminic antioxidant commercially available from Innospec "BHT" -butylated hydroxyl toluene supplied by Sigma Aldrich "DGS 109" -this is a mixed arninic and phenolic antioxidant commercially available from Innospec "DCI-11" -this is a corrosion inhibitor commercially available from Innospec, containing 10-30% N,N-dimethylcyclohexylamine, 10-30% methanol, 1-5% xylene 0-1% ethylbenzene and 30-60% organic acids

Examples 1 to 16

The base gasoline described in Table 1 above was blended with 5 %vol, 10 %vol. and 20 %vol. 2-methyl furan, based on the volume of the formulated gasoline composition (Examples 2, 7 and 12).

-13 -In addition, Examples 3, 8 and 13 contained 2000 ppmw.

of BHT (phenolic antioxidant) relative to the weight of 2-methyl furan in the gasoline composition, Examples 4, 9 and 14 contained 2000 ppmw of DGS-109 (mixed phenolic/aminic antioxidant) relative to the weight of 2-methyl furan in the gasoline composition, Examples 5, 10 and 15 contained 1000 pprnw of AO-22 (aminic antioxidant) relative to the weight of 2-ntethyl furan in the gasoline composition and Examples 6, 11 and 16 contained 200 ppmw of DCI-11 (a corrosion inhibitor) relative to the weight of 2-methyl.furan in the gasoline composition.

HFRP. Lubricity Wear Scar Test Method The lubricity of the gasoline compositions was determined by using a modified HFRR (high frequency reciprocating rig) Lubricity Wear Scar test. The modified HFRR test is based on 1S012156-l using a PCS Instruments HFRR supplemented with the PCS Instruments Gasoline Conversion Kit, and using a fluid volume of 15.0 ml (+1-0.2 ml), a fluid temperature of 25.0°C (+1-1°C), and wherein a PTFE cover is used to cover the test sample in order to minimise evaporation. The results recorded in Table 1 below shows the average recorded lubricity wear scar.

-14 -

Table 1

Example Description Average

lubricity wear scar (microns) 1* Base gasoline 820 2 5% 2MF 552 3 5%2MF+BHT 671 4 5% 2MF + DGS-109 610 5% 2MF + A0-22 678 6 5% 2MF + DCI-11 572 7 10% 2!1F 521 8 10% 2MF + BHT 556 9 10% 2MF + DGS-109 554 10% 2r4F � AO-22 572 11 10% 2MF � DCI-11 387 12 20% 2MF -417 13 20% 2MF + BElT 451 14 20% 2MF � DGS-109 438 20% 2MF + AO-22 408 16 20% 2MF + DCI-l1 303 * Comparative Example As can be seen from the results in Table 1, a reduced lubricity wear scar is observed in the HFRR Lubricity Wear Scar test for the gasoline compositions containing 2-methyl furan (Examples 2-16), compared to the base gasoline, which represents an improvement in the lubricity of the gasoline composition compared to the base gasoline.

Examples 17-26

A further set of experiments was carried out to measure the HFRR lubricity wear scar of various blended gasolines as described in Table 2 below, using the same -15 -HFRR Lubricity Wear Scar test method as used in Examples 1 to 16 above.

Example 17 is a base gasoline. Examples 18, 21 and 24 is base gasoline blended with 5 vol%, 10 vol% and 20 vol% 2MF, respectively.

In addition, Examples 19, 22 and 25 contained 1000 ppmw of AO-22 (an aminic anti-oxidant) relative to the weight of 2-methyl furan in the gasoline composition and ppmw of DCI-ll (a corrosion inhibitor) relative to the weight of 2-methyl furan in the gasoline composition, and Examples 20, 23 and 26 contained 2000 ppmw of DGS 109 (mixed phenolic and aminic antioxidant) relative to the weight of 2-methyl furan in the gasoline composition and ppmw of DCI-1l (a corrosion inhibitor) relative to the weight of 2-methyl furan in the gasoline composition.

The average HFRR lubricity wear scar of each of the gasoline compositions of Examples 17 to 26 is given in

Table 2 below.

Table 2

Example Description Average

Lubricity Wear Scar (microns) 17* Base gasoline 915 18 5% 2MF 795 19 5% 2F + Ao-22 + DCI-ll 793 5% 2MF + DGS 109 + DCI-li 782 21 10% 2MF 535 22 10% 2MF + AO-22 + DCI-11 486 23 10% 2MF + DGS 109 + DCI-1l 502 24 20% 2MF 548 20% 2MF + AO-22 + DCI-11 378 26 20% 2MF + DGS 109 + DCI-1l 351 * Comparative Example As can be seen from Table 2, a reduced lubricity wear scar is observed in the HFRR Lubricity Wear Scar test for the gasoline compositions containing 2-methyl furan compared to the base gasoline which represents an S improvement in lubricity of the gasoline composition compared to the base gasoline. The average lubricity wear scar of the base gasoline is further reduced upon addition of anti-oxidants (aminic antioxidant or mixed phenolic/aminic antioxidant) and corrosion inhibitor, which represents a further improvement in lubricity.

Claims

-17 -CL A I MS1. A gasoline composition comprising (i) an unleaded gasoline base fuel, (ii) from 1 to 30 vol.%, based on the overall gasoline composition, of component A, wherein component A is selected from compounds of formula I: wherein the R3, R4, R5 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups; and (iii) one or more fuel additives selected from pheriolic antioxidants, aminic antioxidants, corrosion inhibitors and mixtures thereof.
2. A gasoline composition according to Claim 1 wherein the gasoline composition has an average HFRR lubricity wear scar of less than 800 microns, preferably less than 700 microns, as measured by the HFRR Lubricity Wear Scar Test t'ethod.
3. A gasoline composition according to Claim 1 or 2 wherein the gasoline composition has a sulphur content of no more than 50 ppmw, relative to the total weight of the gasoline composition.
4. A gasoline composition according to any of Claims 1 to 3 wherein in component A, the R4 and R5 groups are hydrogen, the R3 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups, with at least one of the R3 and R6 groups being a C1_6 hydrocarbyl group. 18 -
5. A gasoline composition according to any of Claims 1 to 4 wherein component A is selected from 2-methyl furan, 2,5-dimethyl furan and mixtures thereof.
6. A gasoline composition according to any of Claims 1 to 5 wherein component A is 2-methyl furan.
7. A gasoline composition according to any of Claims 1 to 6 wherein component A is derived from a biological source material.
8. A gasoline composition according to any of Claims 1 to 7 comprising from 5 to 25 vol.%, based on the overall gasoline composition, of component A.
9. A gasoline composition according to any of Claims 1 to 8 comprising from 8 to 15 vol.%, based on the overall gasoline composition, of component A.
10. A gasoline composition according to any of Claims 1 to 9 wherein the one or more fuel additives is selected from phenolic antioxidarits, aminic antioxidants, and mixtures thereof.
11. A gasoline composition according to any of Claims 1 to 10 wherein the one or more fuel additives comprises one or more corrosion inhibitors.
12. A gasoline composition according to any of Claims 1 to 11 wherein the one or more fuel additives is selected from one or more corrosion inhibitors and one or more antioxidants selected from phenolic antioxidants, aminic antioxidants, and mixtures thereof.
13. Use of from, 1 to 30 vol% component A in a gasoline composition comprising a major portion of a gasoline base' fuel wherein component A is selected from compounds of formula I: -19 -wherein the R3, R4, R5 and R6 groups are independently selected from hydrogen and C1_6 hydrocarbyl groups, for improving the lubricity of the gasoline composition.
14. Use according to Claim 13 wherein the gasoline composition further comprises one or more fuel additives selected from phenolic antioxidants, aminic antioxidants, corrosion inhibitors and mixtures thereof.
15. A method of operating an internal combustion engine, which method involves introducing *into a combustion chamber of the engine a gasoline composition according to any one of claims 1 to 12.