CA1304940C

CA1304940C - Fuel composition for multi-port fuel injection systems

Info

Publication number: CA1304940C
Application number: CA000531645A
Authority: CA
Inventors: Joel R. Siegel; Geoffrey A. Canton; Abraham A. Zimmerman; Joseph Vardi
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1986-03-14
Filing date: 1987-03-10
Publication date: 1992-07-14
Anticipated expiration: 2009-07-14
Also published as: BR8701169A; CN87101878A; NZ219531A; EP0237356B1; DE3775584D1; AU602330B2; KR870008996A; ES2027690T3; AU6998887A; EP0237356A2; KR950001710B1; EP0237356A3

Abstract

ABSTRACT
Vehicle driveabillty problems associated with deposits formed in multi-port fuel injectors are alleviated by delivering fuel comprising a particular amine containing various C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl groups and C1 to C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic or heterocyclic groups Particular amines include bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, and mixtures thereof. Fuels containing the amine are stabilized against emulsions by inclusion in the fuel of certain demulsifiers. In the preferred embodiment, the amine is in combination with an oxide derivative thereof.

Description

aACEtGROUUD OF THE IUVE~ITION

This invention is directed to an anti-fouling fuel composition and to a method for using same. More specifically, the present invention is directed at a fuel composition having particula~ ap-plicability in minimizing and/or preventing injector fouling in gasoline engines e~uipped with electroni-cally controlled multiport fuel injectors.

Over the past several years, improvements have ~een made in the performance of internal combus-tlon engines. One of the most signi~icant lmprovements which ha~ been made ha~ been the widespread use of fuel injection to improve the perormance and fuel economy of internal combu3tion engines. While carburetor-equipped internal combustion engines admix the air and fuel for distribution through a manifold to all of the cylinders, in a fue} injected engine the fuel is in-jected into the manifold close to the intake valve of each cylinder for combustion. Fuel injection systems are of two basic types, mechanically ~-ontrolled and electronically controlled. The early fuel injected engines were controlled mechanically, i.e~, the opera-tion of each injector was controlled by pressure.
Recently, however, the use of electronically con-trolled fuel injection engines has become increasingly widespread. In an electronically controlled fuel in-jection sy~tem sensors disposed in the exhaust are employed to maintain the ai~ to fuel ratio within narrow limits. Electronically controlled fuel in-jection systems offer the same performance and fuel economy benefits that would be achieved with mechani-cally controlled fuel injection systems and also serve to more closely regulate fuel-air mixtures to thereby enable the catalytic converter to oxidize carbon monoxide and hydrocarbons to carbon dioxide and ~imultaneously to reduce nitrogen oxides and thus meet emissions control legislation. Such legislation imposing as it did strict control of exhaust pollutants utimately led to the development and widespread appli-cation of new technologies such as electronic fuel ~n~ection .

It has been found that the electronically controlled fuel injector systems have small port openings which are prone to fouling by deposit~. These deposits are believed to occur, at least in part, by gasoline and oil vapor, which i5 present in close proximity to the injector tip, becoming baked onto the hot surfaces of the injector pintle and on the surfaces of the annulus surrounding the pintle when the engine is shut off. These deposits restrict the fuel flow to that particular cylinder. This, in turn, causes a sensor disposed in the exhaust to detect a higher than desired OxygeQ to fuel ratio. The sensor will attempt t`o correct this condition by increasing the amount of fuel injected into all of the cylinders. This, in turn, will result in a richer than desired fuel to air ratio in the exhaust. The sensor then will attempt to correct this by decreasing the amount of fuel injected into each cylinder. This cyclical adjustment of the fuel to air ratio ranging between too lean a mixture and too rich a mixture can at times result iQ poor operating performance of the vehicle. In addition, close tolerances in this new type of injector and con-currently higher underhood temperature also tend to i304940 enhance deposit formation resulting in poor vehicle driveability and exceeding exhaust pollutant levels set by emissions control legislation.

It has been found that conventional gasoline detergents, which have proven effective in preventing and/or eliminating carburetor deposits are not par-ticularly effective in removing and/or preventing deposit build-up that may occur in electronically con-trolled fuel injection systems. Presently available methods for removing deposits from fuel injector orifices typically comprise either mechanically cleaning the injectors or the addition to the fuel of relatively large quantities of particular additives.
Mechanical cleaning, which may involve either the com-pleté removal of the injector for manual deposit re-moval or the use of polar solvents for flushing the deposits free, is not desired because of the rela-t~ely high C09t and inconvenience. Currently avail-able additiveq are not particularly desirable because product recommendations indicate they must be used at relatively high concentrations, i.e. about one to about two tons per thousand barrels of fuel.

To be useful commercially a gasoline additive for reducing and/or preventing injector port fouling must be effective at low concentration, must not significantly affect the combustion characteristics of the fuel and must not foul the catalytic converter catalyst.

Additives have been added to gasoline to improve certain properties of the fuel. U.S. Patent No. 3,115,400 discloses the use of compounds of the structure 130~9~0 [(CH2)X ly H
R - N"' \ [(CH2)X O)z H

where R i5 a C6-C22 aliphatic hydrocarbon radical, X is an integer from 2 to 4, Y is an integer of at least 1, and Z is an integer of at least 1, for use in motor fuel to prevent or reduce carburetor icing.

' U.S. Patent No. 4,409,000 discloses combination of hydroxy amine~ and hydrocarbon-soluble carboxylic dispersants as engine and carburetor deter-gents for normally liquid fuels. Among the hydroxy amines disclosed are compounds of the formula ~1H - CH - )a H
, R'N ~
t~H - ~ - )b H

where R' may be an alkyl radical containing from'about 8 to about 30 carbon atoms, where R2, R3, R4 and R5 each may be hydrogen and where a and b may be integers from 1 to 75.

U.S. Patent No. 4,231,883 disclo~es the use of a compound of the formu'la ~(R2 )X H
Rl - N
\ (R3 O) . . .
where Rl is a C12-C36 aliphatic 'hydrocarbon group, R2 and R3 are divalent hydrocarbon radicals containing 2-4 carbon atoms and X and Y are integers .

' from 1-4, for friction reduction in lube oils.
Preferred compounds comprise U,N-bis (2-hydroxyethyl) hydrocarbylamines.

U.S. Patent No. 3,387;953 is directed at the use of organo-substituted nitrogen oxides, particularly amine oxides for rust inhibition and as anti-icing a~ents in gasoline. Several representative formulas for amine oxides are given including the following:

~2 I

Rl _ N > 0 where: Rl is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl;
and R2 and R3 are the same or different and are Cl-C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic or heterocylic. a2 and R3 preferably comprise hydroxy substituted alkyls. These compounds typically are added to ~asoline in a concentration within the range of about 2.0 to about 100 pounds of amine oxide per 1,000 barrels of gasoline (ptb). Among the most preferred additives is bis(2-hydroxy ethyl) cocoamine oxide.

U.S. Patent No. 3,594,139 is directed at a rust-inhibitor concentrate that can be blended with gasoline year-round. This patent also discloses the use o~ amine oxides having the aforementioned formula for use as gasoline additives for rust prevention. This patent also discloses a particul~rly preferred con-centrate comprising bis(2-hydroxy ethyl) cocoamine oxide.

~304940 `

The amine oxides described above have been typically used to inhibit rust and carburetor icing, although these amines also were known as carburetor detergents.

It has been discovered that use of hydroxy substituted amine oxides can result in additive losses because of high water solubility and adsorption on polar surfaces.

Accordingly, it would be desirable to pro-vide an additive package for gasoline which will be af~ective in reducing and/or eliminating fouling with-out appreciable additive losses.

It also would be desirable to provide an additive package haYing a demulsifying agent which is effective in the presence of both neutral and basic waters.

Accordingly, it would be desirable to pro-vide a gasoline additive package which is relatively inexpensive and effective at low concentrations to reduce and/or eliminate injector fouling.

It also would be desirable to provide a gasoline additive package which is non-corrosive, non-deleterious to the catalyst, and does not affect the combustion characteristics of the fuel.

It also would be de5irable to provide a gasoline additive package which could be easily added to the finished gasoliné at any point during the storage and/or distribution system.

SUMMARY OF THE INVENTION

The present invention is directed at a fuel composition for minimizing and/or preventing injector fouling in a multiport electronically controlled fuel injected engine. The composition comprises:
A. gasoline B. an anti-fouling agent having the formula:

Rl N

where: Rl is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, sub~tituted alkyl or substituted aryl;
and R2 and R3 independently are Cl-C24 substituted alkyl, aryl, cycloaliphatic or heterocylic; and, C. a demulsifying agent selected from the group consisting of:
i. acylated polyglycols;

ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;

iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and, iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.

In this composition ~1 preferably is C6-C20 alkyl, or alkylated aryl, and R2 and R3 independently are Cl-C12 hydroxy substituted alkyl. In a more preferred composition Rl, comprises C8-Clg substituents derived from fatty acid. The additive preferably is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearyl-amine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof. A
particularly preferred additive is bis(2-hydroxy ethyl) cocoamine. The anti-fouling agent concentration in the fuel typically may range between about 2 to about 200 ppm, (parts per million by weight based on the total welght of the fuel composition) preferably between about 20 to about 80 ppm. ~he active concentration of the demulsifying agent may range between about 0.1 and about 20 ppm, preferably between about 1.0 and about 8 ppm. A preferred demulsifier is selected from the group consisting of:
i. acylated polyglycols;

ii. alkyl phenol-formaldehyde resins and polyglycols; and, iii. oxyalkylated alkylphenol-formaldehyde resin; and mixtures thereof.

The fuel additive also may include a second, amine oxide anti- eOu ling agent having the following structural formula:

I

R4 - N > 0 I

where R4 is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; Rs and R6 independently are Cl-C24 alkyl, aryl, sub-stituted alkyl or aryl, cycloaliphatic, heterocyclic, and mixtures thereof; and, Preferred amine oxide anti-fouling agents include compounds wherein: R4 is C6-C20 alkyl, or alkylated aryl; and Rs and R6 independently are hydroxy sub5tituted Cl-C12 alkyl. Particularly pre-~e~red compounds are compounds wherein Rl comprises a Cg-Clg subst~tuent. The amine oxide additive pre~erably is selected from the group consisting of bis ~2-hydroxy ethyl) cocoamine oxide, bis~2-hydroxy ethyl) stearylamine oxide, dimethylcocoamine oxide dimethyl hydrogenated tallow amine oxide, dimethylhexadecylamine oxide , a~d mixtures thereof. A particularly preferred amine oxide anti-fouling agent is bis~2-hydroxy ethylj cocoamine oxide.

A fuel composition such as gasoline, typically may further comprise: -, A. about 2 to about 200 ppm bis(2-hydroxy ethyl) cocoamine; and, B. about 0.1 to about 20 ppm of a de-mulsifying agent selected rom the group consisting o:

i. acylated polyglycols;

ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;

iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and, iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.

The fuel composition more preferably comprises:

A. about 20 to about 120 ppm bist2-hydroxy ethyl) cocoamine; and, B. about 1 to about 12 ppm of a de-mulsifying agent ~elected from the group consi~ting of:
i. acylated polyglycols;

ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;

iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and, -iv. oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.

.

The preferred fuel composition also ~ay comprise about 4 to about 40 ppm bis(2-hydroxy ethyl) cocoamine oxide.

A preferred fuel additive concentrate for internal combustion engines comprises:

A. about 5 to about 60 wt.~ bis(2-hydroxy ethyl) cocoamine;

B. about 0.25 to about 10 wt.% of a de-mulsifying agent selected from the group consisting of:
i. acylated polyglycols;

ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;

iii. oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and, iv. oxyalkylated alkylphenol-formaldéhyde resins;
and mixtures thereof.
C. about 40 to about 95 wt.% solvent.

The fuel additive concentrate also may com-prise about 1 to about 15 wt.~ bis(2-hydroxy ethyl~
cocoamine oxide.

The solvent preferably comprises an alkyl aromatic hydrocarbon solvent, such as xylene, and a C4~
alcohol, preferably a Cg-C12 alcohol, more preferably a C8 alcohol and most preferably a Cg oxo alcohol.

~ :''4~
;~ .

~3049A0 Where the ratio of the concentration of water relative to amine oxide exceeds about 0.05, a highly water and hydrocarbon soluble alcohol, preferably isopropanol, also should be added.

The present invention also is directed at a method electronically controlled fuel injection system for an internal combustion engine, said method comprising delivering to said fuel injection system a fuel comprised of an effective amount of an additive comprising , where: R1 is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl; R2 and R3 independently are Cl to C24 substituted alkyl, aryl, cycloaLiphatic or heterocylic. The R2 and R3 preferably are hydroxyl âubstituted.

DETAILED DESCE~IPTION OF THE INVENTION

The present invention is directed at a fuel composition, a gasoline additive package, and a method for delivering the fuel composition to a fuel injection system in which the composition has been found to be particularly effective in reducing and/or eliminating injector ~ouling. The present invention is directed at a ~uel co,nprising:

A. gasoline;

, ~ .~, ~., " 1304940 B. an anti-fouling agent having the following 3tructural formula:

Rl - N
. . I

where Rl is C6-C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R2 and R3 independently are Cl-C24 substituted alkyl or aryl, cycloaliphatic, heterocyclic, and mixtures thereof; and, C. a demulsifying agent selected from the group consisting of:
i. acylated polyglycol3;

ii. alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
:, iii. oxyalkylated alkylphenol-formaldehyde resins and polyglyco}s; and, ~: :
:~ iv. oxyalkylated alkylphenol-formaldehyde re~ins; - -: .
and mixtures thereof.

Prefecred anti-fouling agents include ~ compounds wherein- Rl is C6-C20 alkyl, or alkylated : : aryl; and R2 and R3 independently are hydroxy sub-stituted Cl-C12 alkyl. Particularly preferred compounds are compounds wherein RL compriseg a Cg-Clg sub-stituent. The additive preferably is selected from the group consisting of bis (2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy-ethyl) oleyl amine and mixtures thereof. These addi-tives are prepared in accordance with known tech-niques, such as disclosed in U.S. Patent 2,541,678~ ~ _ A particularly preferred anti-fouling agent is bis(2-hydroxy ethyl) cocoamine.
.

Amine oxides also have been found to be effective as anti-fouling agents. While these compounds may be extracted to varying degrees into any water present, these compounds also provide anti-rust properties to the fuels. These compounds have the following structural formula:

R4 N - > O
I

where R4 is C6-C2g alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; Q5 and R6 independently are C~-C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures thereof.

Therefore, the use of these ~mine oxides compounds in combination with the previously described amines may provide an effective anti-fouling composition also providing anti-rust properties. These amine oxides may be prepared by well-known techniques, such as disclosed in U.S. Patent No. 3,387,953.

~304940 ~ here amine and amine oxides are used in combination as the anti-fouling agent, the concentra-tion of the amine typically will range between about 2 and about 200 ppm, preferably between about 16 and about 100 ppm, while the amine oxide concentration will range between about 2 and about 80 ppm, preferably between about 4 and about 40 ppm.

The amine oxide typically has water present from the manufacturing process. While it is possible to remove most of the water, removal of the water to relatively low levels, i.e. a ratio of about 0.02 to about 0.04 of water to amine oxide, adds complexity to the manu~acturing process. Therefore, the amine oxide is commercially available as a solution comprising water and a solvent, which typically is isopropyl alcohol. It has been found that when a concentrate comprising the above amine oxide solution and a solvent containing demulsifiers was admixed with gasoline and terminal tank water bottoms a three phase system resulted, two organic phases and a water phase.

Formation of two organic layers is not desirable, since this was found to result in uneven di~tribution of the amine oxide between layers. In addition, the second organic layer, which has a much higher amine oxide concentration, tends to adhere to surfaces, resulting in additive loss and potential contamination of subsequent hydrocarbon products that might contact these surfaces. It has been found that replacement of a portion of the isopropanol by a higher alcohol, preferably a C4-C12 alcohol, more preferably a C8 oxo alcohol, decreases the likelihood of forming a two organic layer system. While the admixture of the amine with the amine oxide may also decrease the formation of two organic phases, it is preferred that the solvent comprise a C4-C12 alcohol as described above to further decrease the pOS9 ibi lity of two organic phase formation.

A concentrate utilizing both the amine and amine oxide typically also comprises about 40 to about 95 wt.% solvent. A preferred composition range is as follows:
.
Component Wt.% Range Amine 8-32 Amine Oxide 2-8 Solvent Xylene 30-80 C4-C12 alcohol 2-20 Isopropanol 2-16 Water 0.2-1.5 Demulsifier 1-4 The following Comparative Examples and Examples demonstrate the utility of the anti-fouling agent in reducing and/or eliminating fuel injector fouling. In the following Comparative Examples and Examples, the octane rating of the fuel utilized is the posted octane rating which is defined as:

Research Octane + Motor Octane .

COMPARATIVE EXAMPLE r In this test three 1985 Oldsmobile 98's having electronically controlled, fuel injected, 3.8 liter, six cylinder engines were driven on a commer-cial, unleaded, 87 octane reference fuel having a detergent concentration of about 32 ppm by weight of the fuel for approximately 3500 miles under the fol-lowing driving cycle: 0.5 hours city-type driving, 0.5 hour engine off, 0.5 hour highway driving, 0.5 hour engine off. Driveability on all four vehicles became poor to very poor. The vehicles then were driven for 300 miles with a commercial premium grade 92 octane unleaded fuel containing 2.5 times the detergent used in the above reference fuel. Driveability remained unchanged. The data in Table I below show that there was still a marked reduction in fuel flow indicating that a high level of deposit was unaffected by the detergent even at the high treat rate. The percent fuel flow reduction was determined by meaSuriQg the volume of a mineral spirit that flowed through the injector under predetermined standardized conditions, including fuel pressure, pulse width and duty cycle.
The percent reduction is calculated using the formula:

Reduction = Vclean ~ Vdirty x 100%
Vclean where Vclean and Vdirty are the measured volumes of mineral spirit passed through the clean and dirty fuel injectors.

TABLE I
% FLOW REDl~CTION THROUG~ INJECTOR PORTS
Cyl # l 2 3 4 5 6 Car A 11 12 35 30 7 l0 Car 8 7 9 12 38 9 14 Car C 22 ll 28 4 ll 10 Typical 2 2 0 0 2 New Injectors ~ rom Table I it can be seen that this con-ventional, known carburetor detergent was ineffective in removing deposits from injector ports and in fact permitted deposits to form.

COMPARATIVE EXAMPLE II

A 1985 Chrysler Le~aron equipped with a 2.2 liter turbocharged engine having electronically con-trolled fuel injection was driven for 2858 miles on a mileage accumulation dynamometer using a typical regular grade, 87 octane, unleaded, detergent-free gasoline. The driving was based on repetition of the following cycle: 30 minutes city driving, 30 minutes engine off, 30 minutes highway driving, 30 minutes engine off. The driveability became very poor as typified by cough idle, severe hesitation, bac~fire and roughness during acceleration. The hydrocarbon emis-sions measured be~oLe the catalytic converter ~ere 804 ppm at engine idle and 725 ppm at 2500 rpm. The in-~30~940 jector fouling also was measured using a pressure dif-ferential test. In this test the fuel rail is pres-surized to 49 psig and an injector is pulsed for 0.5 seconds. The difference in the pressure drop between the injectors is a rough measure of the degree to which the injectors are obstructed, i.e. the greater the numerical difference between the highest and lowest values, the greater the injector fouling. A summary of the results at 2585 miles on the detergent-free fuel are set forth in Table II as the measurements at 0 miles after HECA addition.

EXAMPLE I

Following the test set forth in Comparative Example II, the vehicle was refueled with the same fuel except that the fuel also cont~ined 80 ppm of bisl2-hydroxy ethyl) cocoamine (HECA). The vehicle then was driven on the following cycle: 15 minutes city driving, 30 minute3 highway driving, 15 minutes city driving, 2 hours engine off. This test continued until 308 miles were accumulated on the vehicle. At the end of this test period the driveability was very good. The hydro-carbon emissions at idle before the catalytic converter were reduced to 65 ppm and to 16 ppm at 2500 rpm. The emissions before the catalytic converter at idle and at 2500, rpm and the pressu~e differentials measured at various intervals during the clean-up driving are sum-marized in Table II. The injector flow reduction mea-surements are summarized in Table III.

.

From the data of Example I and Tables Il and III, it can be seen that the use of a relatively low concentration of HECA was able to produce a signifi-cant improvement in driveability. The idle emissions were significantly reduced and the pressure differen-tial and percent flow reduction of the flow injectors were returned to "as new" conditions after a relative-ly few miles of driving.

13~4940 o u O ~ I o a~

V ~
U~
_~ r~

,~
U

o U~ o~
O
o Z U o ~ o o U ~ ~ ~ co In o ~o ..c ~:

O d~ CO CO ~ O ~
~ C) 3 O -~ O O o .~
O C~ ~:
~ ~1 U~ ~ ~P ~ U~ U~ U7 U~ O ~
~; a~

E~O
Z
¢ C~ ~
O ~ o a- x ~3 ~ 2 1~ e~ O
_I

TABLE III
PORT INJECTOR FLOW REDUCTION

MIL~S DRIVEN
AFTEa HECA $NJECTO~ NO. 1 2 3 ADDITION
308 ~ FLOW REDUCTION 0 0 0 COMPAQATIVE EXAMPLE III

A second 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine was driven on a mileage accumulation dynamometer using a regular grade 87 octane unleaded, detergent-free gasoline from a dif-ferent batch from that of Comparative Example II and Example I. The same driving cycle was used in this Comparative Example as was used in Comparative Example I. The engine wa~ judged to be fouled and the drive-ability poor after 4016 miles.

The emissions before the catalytic converter and the pre sure differential across each injector were measured and are presented in Table IV as the measure-ment~ at 0 miles after HECA addition.

EXAMPLE II
, Approximately 60 ppm of bis~2-hydroxyethyl) cocoamine was added to the fuel of Comparative Example III and the vehicle of Comparative Example III was d~iven on the same driving cycle described in Example I. Measurements o~ the emissions before the catalytic converter and the pressure differential across each injector were measured as previously described. These '' ..

results are presented in Table IV. Driveability was judged to be good after only 357 miles of driving. At the termination of the test the injectors were removed and flow tested as previously described. These results are presented in Table V.

I o o Ut ~ ~ o U~ ~
~ I U~ o o Z ~ ¦ N a~
O
C~ O O O
~ ~ O ~ ~D
- ~ ~
~ I O O U

t_~

~ ~ ol ~ ~ ~
~ u "I
C) C~
E~ C~
~ :~:
~.~

O d~ I~
~ O
li3 ~) -~ ~ ~ O
; ~Z .
o C~ :~
Z U' :
.
: E~ O
o ~:
~ O co ._~
C~
~:

TABLE V
POR~ rNJECTOR FLOW REDUCTION

MILES DRIVEN
AFTER HECA INJECTOR NO. 1 2 3 4 ADDITION
359 % FLOW REDUCTION 5 2 1 O

From a review of Tables II-V it can be seen that the use of relatively low concentrations of HECA
was able to reduce the injector tip deposits in a rela-tively short period of time. By comparison, the use of a conventional ca~buretor detergent was unable to prevent a relatively rapid deposit buildup of injector tip deposit~.

While the data presented above has demonstrated the utility of the anti-fouling agent in gasoline, the anti-fouling agent also may be of utility in other fuels, such as diesel fuel.

While the pre:sently described anti-fouling agent may be used alone, it also may be desirable to utilize the present invention in combination with a d3~ifying agent to facilitate the separation of the gasoline ~rom any foreign substances which may be present in the distribution system, such as water and sediment.

The water, if any, typically has a pH
ranging from about 7 to about 13. Thus, a demulsifying agent for use with the anti-fouling agent preferably should be effective over this pH range. The following Comparative Examples and Examples demonstrate the utility of various demulsifying agents.

COMPARATIVE EXA~PLE IV

In this Comparative Example the effective-ness of various commercially available demulsifying agents were tested in a 90 wt.% fuel - 10 wt.~ water system. The fuel contained an additive package com-prising approximately 60 ppm HECA and 2 ppm of the various additives noted below. The effectiveness of the various demulsifying agents was determined using a modified Multiple Contact Emulsion Test. In this test 10 ml of terminal water bottoms having a pH of approxi-mately 10 was added to separate half-pint bottles. To each bottle was added 100 ml o~ gasoline. ~he bottles were capped, placed on their sides in a mechanical shaker and agitated at approximately 180 cycles per minute for ten minutes. The bottles then were placed upright and allowed to stand for 1 hour. The mixture then was rated considering the gasoline layer, the water layer and the interface using the rating scale set ~orth in Table VI below. After the ratings were completed, the gasoline level was sucked down to a level about 1/4 inch above the interface or emulsion layer without disturbing the interface or water layer.
The withdrawn fuel was discarded and-100 ml of fresh gasoline was added to each bottle. The mixture was then shaken and the test repeated for the indicated number of times with the worst rating noted. The trademarks of the commercially available additives utilized, the worst ratings Oe each mixture and the number of times the test was run are set forth in Table VII below.

~;, ~.

~304940 TABLE VI
RATING SCALE ~OR REPORTING EM~LSION TEST REUSLTS

RATING DESCRIPTION OF EMULSION
v O No skin or interface 1 Slight skin on interface - not completely continuous 2 Thicker skin on interface - usually completely continous 3 Incipient emulsion 1/8 as thick as water layer 4 Emuision 1/4 as thick as water layer Emulsion 3/8 as thick as water layer 6 Emulsion 1/2 as thick a~ water layer 7 Emulsion 5/8 as thick as water layer 8 Enulsion 3/4 as thick as water layer 9 ~mulsion 7/8 as thick as water layer:
Emulsion completely filling water layer Emulsion of maximum severity , , ~: , , -' 130~940 TABLE VI I
EMULSION TEST RESULTS

WORSTNO. OF TIMES
DEMULS I F I ER DESCR I PT ION RAT I NGTEST RUN
, ~ .
Tolad T-292 3 2 T~( Tolad T-347 3 2 Tola3 T-370 4 NalcoT~5450 4 Nalco 5451 3 4 Nalc~5452 3-4 4 Nalc3 5453 4 Nalco 85B~-194 4 N~lFBD-a29 4 : :

.
.

~ ' . ..
"~ , .

~304940 EXAMPLE III

A 100 ml gasoline sample containing 60 ppm of HECa was admixed with 10 ml of the terminal water bottoms of Comparative Example IV; However, in place of the demulsifiers listed in Table VII the following de-mulsifiers were utilized individually: Tolad T-500;
Tolad T-284; Tolad T-286; Tolad T-326; and Nalco 5455.
The modified Multiple Contact Emulsion Test previously described was utilized to determine the efEectiveness of each demulsifier. These test results are summarized in Table VIII below. A description of each additive is pre~ented in Table IX below.
TABLE VIII

WORSTNO. OF TIMES
DEMULSIFIER DESCRIPTION RATING TEST RUN
.
Tolad T-284 2 4 Tolad T-286 1-2 4 Tolad T-326 2 2 Tolad T-500 2 4 Nalco 5455 2 4 , 13049~0 TABLE IX
DEMULSIPIER DESCRIPTIONS

Demulsifier Description Tolad T-284* Solution of acylated polyglycols in aromatic hydrocarbons Tolad T-286* Alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins in aromatic hydrocarbons and isopropyl alcohol Tolad T-326* Oxyalkylated alkylphenol-formaldehyde resins and polyglycols in aromatic naphtha Tolad T-500* Oxyalkylated alkylphenol-formaldehyde resins in aromatic hydrocarbons and alkanols Nalco 5455*~ Oxyalkylated alkyl phenol-formalde-hyde res~n in aromatic solvent * Manufactured by Tretolite Division of Petrolite Corporation, St. ~ouis, Missouri ** Manufactured by Nalco Chemical Company, Oak Brook, Illinois.

COMPA~ATIVE EXAMPLE V

A 1985 Chrysler LeBaron equipped with a 2.2 liter turbocharged engine was driven on a mileage accumulation dynamometer using a regular grade a7 octane unleaded detergent-free fuel. The driving cycle to foul the injectors was 30 minutes city-tyPe driving, 30 minutes soak, 30 minutes highway driving, 30 minutes soak. The engine was judged to be fouled after 2,300 miles.

The emissions before the catalytic converter and the pressure differential across each injector were measured and are presented in Table X as the measurement at 0 miles after additive addition.

EXAMPL~ IV

This Example demonstrates the utility of uai~g an additive comprising the combination of an amine and an amine oxide in cleaning up fouled injec-tors in the vehicle of Comparative Example V. The fuel utilized was similar to that of-Comparative Example V, but further comprised 80 ppm of bis~2-hydroxy ethyl) cocoamine and 10 ppm of bis(2-hydroxy ethyl) cocoamine oxide. The driving cycle was the same as that of Example r. After 301 miles of driving the driveability went from very poor to good.

The measurements of the emissions before the catalytic converter and the pressure differential across each injector also were measured as previously described. These results also are presented in Table X. At the termination of thé test the injectors were removed and flow tested as previously described. These results are presented in Table XI.

Based on these results, it can be seen that the ~se of an additive comprising the amine and amine oxide in combination cleaned fouled injecto~s. Addi-tional tests were run on other test vehicles. In almost all cases it has been found that this combina-tion of amine and amine oxide cleaned fouled injectors in a relatively short period.

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TABLE XI
PORT INJECTOR FLOW REDUCTION
MILES AFTER
ADDITIVE INJECTOR NO. 1 2 3 4 ADDITION
301 % FLOW REDUCTION 2 1 4 2 Where the presently described invention is used as a gasoline additive, the additive package may be added to the gasoline at any point after the gasoline has been refined, i.e., the additive package can be added at the refinery or in the di~tribution system .

Claims

1. A fuel composition for an internal combustion engine, said fuel composition comprising:
(a) gasoline:
(b) an anti-fouling agent having the formula wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl: R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic; and (c) a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols:
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins:
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and (iv) oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.

2. The fuel composition of claim 1 wherein R1 is C6 to C20 alkyl, or alkylated aryl, and R2 and R3 independently are hydroxy substituted C1 to C12 alkyl.

3. A fuel additive concentrate for internal combustion engines, said additive concentrate comprising:
(a) about 5 to about 60 wt.% bis(2-hydroxy ethyl) cocoamine;
(b) about 0.25 to about 10 wt.% of a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins:
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and (iv) oxyalkylated alkylphenol-formaldehyde resins:
and mixtures thereof; and (c) about 40 to about 95 wt.% solvent.

4. The fuel additive concentrate of claim 3 further comprising about 1 to about 15 wt.% bis(2-hydroxy ethyl) cocoamine oxide.

5. A fuel additive concentrate for internal combustion engines, said additive concentrate comprising:
(a) about 8 to about 32 wt.% amine having the formula:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl; R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic:
(b) about 2 to about 8 wt.% amine oxide having the following structural formula:

where R4 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R5 and R6 independently are C1 to C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures thereof;
(c) about 40 to about 95 wt.% solvent; and (d) about 1 to about 4 wt.% demulsifier selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins:
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and (iv) oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.

6. A method for reducing and/or preventing fouling in a multi-port, electronically controlled fuel injection system for an internal combustion engine, said method comprising delivering to said fuel injection system a fuel comprised of an effective amount of an anti-fouling agent comprising:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl: R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic.

7. The method of claim 6 wherein R1 is C6 to C24 alkyl, or alkylated aryl;
and R2 and R3 independently are hydroxy substituted C1 to C12 alkyl.

8. A method for reducing and/or preventing fouling in a multi-port fuel injection system having a sensor means disposed in the exhaust adapted to regulate the air to fuel ratio, said method comprising delivering to the fuel injection system a fuel comprising:
(a) unleaded gasoline;
(b) an anti-fouling agent selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof; and (c) a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and (iv) oxyalkylated alkylphenol-formaldehyde resins;
and mixtures thereof.

9. In a method for combusting gasoline in an internal combustion engine wherein gasoline is delivered to the combustion zone of the engine by means of a multi-port, electronically controlled fuel injection system, the improvement which comprises combusting a gasoline including:
(a) an effective amount of an anti-fouling agent selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof; and (b) a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins:
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols: and (iv) oxyalkylated alkylphenol-formaldehyde resins;
and mlxtures thereof.

10. A fuel composition for an internal combustion engine, said engine composition comprising:
(a) gasoline;
(b) an amine anti-fouling agent having the formula:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl: R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic: and (c) an amine oxide anti-fouling agent having the following structural formula:

where R4 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R5 and R6 independently are C1 to C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures thereof.

11. The composition of claim 1 wherein the amine anti-fouling agent is present in an amount of from about 2 to about 200 ppm by weight based on the total weight of the fuel composition.

12. The composition of claim 11 wherein the amine anti-fouling agent is present in an amount of 20 to 80 ppm.

13. The method of claim 8 wherein the amine anti-fouling agent is present in an amount of from about 2 to about 200 ppm by weight based on the total weight of the fuel composition.

14. The method of claim 13 wherein the amine anti-fouling agent is present in an amount of 20 to 80 ppm.

15. The composition of claim 10 wherein the amine anti-fouling agent is present in an amount of from about 2 to about 200 ppm by weight based on the total weight of the fuel composition and the amine oxide anti-fouling agent is present in an amount of about 2 to about 80 ppm.

16. The composition of claim 15 wherein the amine anti-fouling agent is present in an amount of 16 to 100 ppm and the amine oxide anti-fouling agent is present in an amount of 4 to 40 ppm.

17. The fuel composition of claim 2 wherein R1 comprises C8 to C18 substituents.

18, The fuel composition of claim 17 wherein R1 is derived from fatty acid.

19. The fuel composition of claim 18 wherein the additive is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof.

20. The fuel composition of claim 19 wherein the anti-fouling agent is bis(2-hydroxy ethyl) cocoamine.

21. The fuel composition of claim 20 wherein the demulsifying agent is selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl phenol-formaldehyde resins and polyglycols: and (iii) oxyalkylated alkylphenol-formaldehyde resins: and (iv) mixtures thereof.

22. A method for reducing and/or preventing fouling in a multi-port electronically controlled fuel injection system for an internal combustion engine, said method comprising delivering to said fuel injection system a fuel comprised of an effective amount of an anti-fouling agent comprising (A) an amine having the structural formula:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryls R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic: and (B) an amine oxide having the structural formula:

where R4 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl R5 and R6 independently are C1 to C24 alkyl, aryl, substituted alkyl or aryl, acycloaliphatic, heterocyclic and mixtures thereof.

23. The method of claim 22 wherein R1 and R4 are C6 to C20 alkyl, or alkylated aryl, and R2, R3, R5 and R6 independently are hydroxy substituted C1 to C12 alkyl.

24. The method of claim 23 wherein R1 and R4 comprise C8 to C18 substituents.

25. The method of claim 24 wherein R1 and R4 are derived from fatty acid.

26. The method of claim 25 wherein additive (A) is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof, and additive (B) is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine oxide, bis(2-hydroxy ethyl) stearylamine oxide, and mixtures thereof.

27. The method of claim 26 wherein said anti-fouling agent comprises bis(2-hydroxy ethyl) cocoamine and bis(2-hydroxy ethyl) cocoamine oxide.

28. The method of claim 1 wherein said fuel comprises a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and (iv) oxyalkylated alkylphenol-formaldebyde resins; and (v) mixtures thereof.

29. The method of claim 28 wherein said anti-fouling agent comprises bis(2-hydroxy ethyl) cocoamine and bis(2-hydroxy ethyl) cocoamine oxide.

30, A fuel composition for an internal combustion engine, said fuel composition comprising:
(1) gasoline; and (2) an effective amount of anti-fouling agent comprising (A) an amine having the structural formula:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl; R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic; and (B) an amine oxide having the structural formula:

where R4 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R5 and R6 independently are C1 to C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures thereof.

31. The fuel composition of claim 30 wherein R1 and R4 are C6 to C20 alkyl, or alkylated aryl; and R2, R3, R5 and R6 independently are hydroxy substituted C
to C12 alkyl.

32. The fuel composition of claim 31 wherein R1 and R4 comprise C8 to C18 substituents.

33. The fuel composition of claim 32 wherein R1 and R4 are derived from fatty acid.

34. The fuel composition of claim 33 wherein additive (A) is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof, and additive (B) is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine oxide, bis(2-hydroxy ethyl) stearylamine oxide, and mixtures thereof.

35. The fuel composition of claim 34 wherein said anti-fouling agent comprises bis(2-hydroxy ethyl) cocoamine and bis(2-hydroxy ethyl) cocoamine oxide.

36. The fuel composition of claim 30 wherein said fuel comprises a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;

(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols;
(iv) oxyalkylated alkylphenol-formaldehyde resins; and (v) mixtures thereof.

37. The fuel composition of claim 36 wherein said anti-fouling agent comprises bis(2-hydroxy ethyl) cocoamine and bis(2-hydroxy ethyl) cocoamine oxide and said demulsifying agent is selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols;
(iv) oxyalkylated alkylphenol-formaldehyde resins; and (v) mixtures thereof.

38. A fuel additive concentrate for gasoline, said additive concentrate comprising:
(1) about 5 to about 60 wt.% of an anti-fouling agent comprising (A) an amine having the structural formula:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl; R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic; and (B) an amine oxide having the structural formula:

where R4 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl, substituted aryl; R5 and R6 independently are C1 to C24 alkyl, aryl, substituted alkyl or aryl, cycloaliphatic, heterocyclic and mixtures thereof;
(2) about 0.25 to about 10 wt.% of a demulsifying agent selected from the group consisting of:
(i) acylated polyglycols;
(ii) alkyl aryl sulfonates, polyglycols, oxyalkylated alkylphenol-formaldehyde resins;
(iii) oxyalkylated alkylphenol-formaldehyde resins and polyglycols; and (iv) oxyalkylated alkylphenol-formaldehyde resins; and (v) mixtures thereof; and (3) about 40 to about 95 wt.% solvent comprising an alkyl aromatic hydrocarbon and an alcohol.

39. The fuel additive concentrate of claim 38 wherein R1 and R4 are C6 to C20 alkyl, or alkylated aryl; and R2, R3, R5 and R6 independently are hydroxy substituted C1 to C12 alkyl.

40. The fuel additive concentrate of claim 39 wherein the alcohol comprises a C4 to C12 alcohol.

41. The fuel additive concentrate of claim 39 wherein the alcohol comprises isopropanol and a C8 oxo alcohol.

42. The fuel additive concentrate of claim 39 wherein said alkyl aromatic hydrocarbon comprises xylene.

43. The fuel additive concentrate of claim 39 wherein said amine comprises bis(2-hydroxy ethyl) cocoamine and said amine oxide comprises bis(2-hydroxy ethyl) cocoamine oxide.

44. A method for reducing and/or preventing fouling in a multi-port electronically controlled fuel injection system for an internal combustion engine, said method comprising delivering to said fuel injection system a fuel comprised of an effective amount of an anti-fouling agent comprising:

wherein R1 is C6 to C24 alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl; R2 and R3 independently are C1 to C24 substituted alkyl, aryl, cycloaliphatic or heterocyclic.

45. The method of claim 44 wherein R1 is C6 to C24 alkyl, or alkylated aryl;
and R2 and R3 independently are hydroxy substituted C1 to C12 alkyl.

46. The method of claim 45 wherein R1 is a C8 to C18 substituent.

47. The method of claim 46 wherein R1 is derived from fatty acid.

48. The method of claim 47 wherein the anti-fouling agent is selected from the group consisting of bis(2-hydroxy ethyl) cocoamine, bis(2-hydroxy ethyl) tallow amine, bis(2-hydroxy ethyl) stearylamine, bis(2-hydroxy ethyl) oleyl amine and mixtures thereof.

49. The method of claim 48 wherein said anti-fouling agent comprises bis(2-hydroxy ethyl) cocoamine.