CA1073207A - Anti-knock internal combustion engine fuel - Google Patents

Abstract

COMPOSITION AND METHOD
ABSTRACT OF THE DISCLOSURE

An improved fuel composition comprising a major amount of hydrocarbons boiling in the gasoline boiling range; a minor amount of at least one hydrocarbon-soluble compound of a metal selected from the group consisting of manganese, technetium, rhenium and mixtures thereof capable of improving the octane number rating of the composition; a minor amount of at least one aliphatic alcohol containing from 1 to about 8 carbon atoms per molecule; and a minor amount of water wherein the compound and the combination of alcohol and water are present in mutually activating amounts to improve the octane number rating of the fuel composition.
An improved method for fueling an internal combustion engine using the composition described above is also disclosed.

Description

1~73'~07 This invention relates to an impro~edfuel composition.
More particularly-, the invention relates to fuel cornpositions useful, for example, in fueliny internal combustion engines, which have improved anti-knock properties~
Fuel compositions often include at least one additive to improve the anti-knock properties of the composition. The anti-knock properties of a fuel composition are directly related to, and often measured by, the octane number rating of th~ composition.
Thus, if the octane number rating of a ~uel composition increases, the anti-knock properties of that composition improve.
In recent years, fuel marketers have worked diligently to im~rove the anti-knock properties or octane number ratin~
of fuel compositions. Because of the capital investment required, e.g., for additional petroleum refining capacity, to improve the inherent anti-knock properties of hydrocarbon-based fuel compositions, fuel additives which improve fuel anti-knoc~ proper~
ties by a fraction of a single octane num~er re2resent si~nificarlt developments. However, a continuing need is apparent to provide additive systems for fuel compositions which increase the octane number rating of the compositions.
Therefore, onelobject of the present invention is to pro~ide a fuel composition having improved anti-knock propertiésJ ~ -as measured by an improved octane number rating.
; Another object of the present invention is to provide an improved method for fueling an internal combustion engine ` wherein improved engine per~ormance, e.g., reduced tendency to knock, results. Other objects and advantages of the prFsent inYention will become apparent hereinafter.
~ 1 improved fuel composition/ e.g.~ for fueling an internal combustion engine, has now been discovered. The `

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.<, 3Z~7 composition comprises a major amount of hydrocarhons boiling in the gasoline boiliny range; a minor amount of at least one hydrocarbon-soluble compound of a metal selected from the group consisting of manganese, technetium, rhenium, and mixtures thereof capable of improving the octane number rating of the composition;
a minor amount of atlleast one aliphatic,preferably monohydroxy, alcohol containing f~om 1 to about 8, preferably from 1 to about 4, carbon atoms per molecule; and a minor ~mount of waterO The metal-containing compound and the combination of alcohol and wat~r are present in the present fuel compositions in mutually activating amounts to improve the octane number rating of the fuel composition. Thus, minor amounts of at least one of c~rtain metal-containing compounds, aliphatic alcohols and water provide a hydrocarbon fuel composition having an unexpectedly improved octanejnumber rating. These compositions may be used in an improved method of fueling an internal combustion engine to achieve outstanding benefits, e.g., reduced tendency of the engine to knock during operation.

- ~ .
The base fuel of the compositions of the present 2a i~vention comprises a mixture of hydrocarbons boiling in the gasoline range. Typically, the base fuel comprises hydrocarbons which boil primarily in the range from about 50F. to about 500F.
This base fuel may be composed of straight chain or branched chain paraffinsl cyclo-paraffins, olefins and aromatic hydr3-carbons or any mixture of these. This base fuel can be derived from straight run naphtha, polymer gasoline, natural gasoline or from catalytically cracked or thermally cracked hydrocarbons, cat:alytically reformed stocks and the like. Any .
conventional substantially hydrocarbon fuel base may be employed in t}~e practice of this invention~

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~73~V7 The hase fuel may contain any of the additives normally employed in a motor fuel. For example, the base uel may contain anti-icing agents, detergents, demulsifiers, corrosion inhihi~ors, dyes, deposit modifiers, lead scavengers, multipurpose additives and the like. In addition, the present base fuel may include other conventional anti-knock components, such as tetral~.yl lead compound including tetraethyllead, tetramethyllead, tetra-butyllead, mi~tures thereof and the like. However, preferably the present fuel compositions are substantially lead free.
The hydrocarbon-, e.g., gasoline-,soluble manganese, technetium and/or rheni~ compounds useful in the present invention in general, are defined as those compounds which are capable of improving the octane number rating of the present fuel compositions.
Specific examples of such compounds and methods for their prepara-tion are conventional and well known in the art. For instance, see: United States Patents 3,3~8,440, 2,~59,604; 2,960,450;
2,~68,599; and ~,868,700 among others. The present compositions preferably include from about 0.01 grams./gal. to about 10 grams./
gal., more preferably from about O.OS grams./gal. to about 2Q 6 grams./gal. of the presently useful metal compounds, calculated as elemental metal. That is, in a preferred embodiment, the present compositions include from about 0.01 grams to about 10 grams of manganese, technetium, rhenium and mixtures thereof (in the form of hydrocarbon-soluble compounds) per gallon of fuel compositions. Preferably, the metal compounds used in the present compositions are compounds of manganese.
In one embodiment of the presen~ invention, the presently useful metal compounds can be represented by the following structure~
~ R2 ~ 3 J

~3~
.~ ..
,

3'~7 .
: and mixtures thereof, wherei.n each Rl, R2, R3, R4 and R5 is independently, i.e., can be the same or di.fferent, selected frcm the group consisting of hydrogen and monovalent substantially hydrocarbonaceous radicals containing from 1 to about 20, prefer~
ably from 1 to about 10, carbon atoms; n is an integer equal to 1 or 2 and p is an integer equal to zero or 3, provided that the s~n of 3, n and p equal 6, and M is a. metallic element selected from the group consisting of manganese, technetium and rhenium.
Preferably, n is equal to 1 and p is equal to 3. The term "substantially hydrocarbonaceous radicals" referred to above, includes those radicals which are compound~ primarily of carbon and hydrogen and also includes radicals which contain, in addition, minor amounts of substituents, such as oxygen, halide, sulfur, nitrogen and the like which do not substantially effect the ; hydrocarbon character of the radicals. :
, the R~, R2, R3, R~ and R5 groups of the above metal-containing compounds can be alkyl radicals such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isohutyl, ~.
sec-butyl, t-butyl, n-amyl, and the various positional isomers thereof as, for.example, l-methyl-butyl, 2-methyl-butyl, 3-methyl- :
~ butyl, l,l-dimethyl-propyl, 1~2-dimethyl-propyl, 2,2-dimethyl-propyl, and l-ethyl-propyl, and likewise the corresponding straight and branched chain isomers, of hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl~
~`~ hexadecyl, heptadecyl, octodecyl, nondecyl, eicosyl and the li.ke.
In addition, these monovalent essentially hydrocar~on radicals : may be alkenyl radicals such as ethyl, ~-propenyl, ~2-propenyl, :~ .
isoprope.nyl, ~l~butenyl, ~2-butenyl, ~3~butenyl, and the : corresponding branched chain isomers thereof as, for example, .~I-isohutenyl, ~2-isobutenyl, ~I-sec-butenyl, ~-sec~butenyl, includiny l-methylene-~2-propenyl, ~I-pentenyl, ~2~pentenyl, ' ' '; .
, ~, ' - . ' ~7~2~7 ~3-pentenyl, ~4-pentenyl, and the corresponding branched chain isomers thereof;~l-hexenyl, ~ 2 -hexenyl, ~3-hex~nyl, ~ 4 -hexenyl, ~5-hexenyl, and the correspondi.ng branched chain isomers thereof, including 3,3-dimethyl-~'-butenyl; 2,3-dimethyl-~-butenyl;
2,3-dimethyl-~ 2 -butenyl; 2,3-dimethyl-~3-butenyl; and l-methyl-l-ethyl-~2-p~openyl; and similarly, the VAXioUs isomers of heptenyl, lctenyl, nonyl, decenyl, undecenyl, dod~-cenyl, tridecenyl, tetradecenyl, penta~ecenyl, eicosenyl and the liXe.
In addition, the Rl, R2, R3, R4, and R5 groups can be aryl radicals, such a~, for example, phenyl, a-naphthyl., ~-naphthyl, a-anthryl, ~-an~hryl, y-anthryl, and the like includin~
the various monovalent radicals o~ such aromati.cs, e.g., indene, isoindene, acenaphthene, fluorene, phenanthrene, naphthacene, chrysene, pyrene, triph~nyl~ne, and the like~
In addition, the Rl, R2, R3, R4 and R5 groups can be aralkyl radicals such as, for example, benzyl, a-phenyl-ethyl, phenyl-ethyl~ a-phenyl-propyl, ~-phenyl-propyl, y-phenyl-propyl, a-phenyl-isopropyl, ~-phenyi-isopropyl, a-phenyl butyl, ~-phenyl-butyl, y-phenyl-butyl, ~-phenyl-butyl, a-phenyl-isobutyl, ~-phenyl-isobutyl, y-phenyl-jsobutyl, a-phenyl-sec-butyl, ~-phenyl-sec-butyl, y-ph~nyl-sec-butyl, ~-phenyl-t~butyl, . .
a'-naphthyl methyl, ~'-naphthyl-methyl, a-(a'-naphthyl)-ethylr -(~'-naphthyl)-ethyl, ~-(a'-naphthyl)-ethyl, ~ '-naphthyl) ethyl, a-(a'-naphthyl)-propyl, a-(~'-naphthyl)-propyl, '-naphthyl)-propyI, ~ naphthyl)-propyl, y ~a'-naphthyl)-:; pxopyl, y~ naphthyl)-propyl, a-(al-naphthyl)~isopropyl, a-(~'-naphthyl)-i.sopropyl, a-(a'-naphthyl)butyl~ a~ naphthyl)~
butyl, ~-(a'-naphthyl)-butyl, ~ '-naphthyl)-bu~yl~ y-(a'- :.
naph~hyl)-butyl,~ '-naphthyl)-butyl, ~-(a'-naphtllyl)-butyl, ; ~5~
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~3732~7 ~(~'naphthyl)-butyl, ~(~'-napht~yl)-isobl1t~ naphthyl) -isobutyl, ~(~'~naphthyl)-isobutyl, ~(~ naphthyl)-iso~utyl, y-(~'-naphthyl)-isobutyl, r ( ~-naphthyl)-isobutyl, ~- ~'-naphthy3.) -sec-butyl, ~ ' naphthyl)-sec-butyl, ~ '-naphthyl)~sec-butyl, ~ naphthyl)-sec-butyl, y-(a'-naphthyl)-sec-butyl, y-(~'-naphthyl)-sec-butyl, ~-(u'-naPhthYl) t-butyl, ~ '-naphthyl) -t-butyl, the corresponding a'~ and ~'~naphthyl derivatives of n-amyl and the ~arious positional isomers thereof such as, ~or example, said derivative~ of l-methyl-butyl, 2-methyl-butyl, 10 3-methyl-butyl, l,l-dimethyl-propyl, 1,2-dimethyl-propyl, 2,2-dimethyl-propyl, l-ethyl-propyl, and likewise said derivatives of the corresponding isomers of hexyl, heptyl, octyl, and the like, including eicosyl. Other such aralkyl derivatives of the metal-containing compounds useful in the pre~ent invention include the ~'- and ~ I - t and y'-anthyl derivatives of alkyl .-radicals, such as, for example, a' anthryl-methyl, ~
anthryl~-ethyl, ~-(y'-anthryl)-ethyl, a-~a'~anthrYl)-butYl, anthryl-2-methyl-amyl, and the like and the corresponding alkyl deri~atives of phenanthrene, fluorene, acenaphthene, .
chrysene, pyrene, triphenylene~ naphthacene, and the like.
: In addition, the Rl, R2, R3, R4 and RS groups of the above-described metal-containing compounds can ~e alkaryl such as, for example, o-tolyl, m-tolyl, p-tolyl, o-ethylphenyl, :: m-ethylphenyl, p-ethylphenyl, o-n-propylphenyl, m-n-propyl-phenyl, p-n-propylphenyl, o-isorpopylphenyl, m-iso propyl-phenyl, p-isapropylphenyl, 2-methyl-~-naphthyl, 3-methyl ~-naphthyl,

4-methyl-~-naphthyl, 5-methyl-a-naphthyl, 6-methyl-~-naphthyl, : 7-methyl-~-naphthyl, 8-met.hyl-~- naphthyl, l-ethyl-~-naphthyl, 3-ethyl-~- naphth~l, 4-ethyl-~-naphthyl, 5-ethyl~ naphthyl,.
6-ethyl-~~naphthyl, 7-ethyl-~-naphthyl, 8-ethyl-~-naphthyl, 2,3-di-pxopyl-~-naphthyl, 5,8-di-isopropyl-~ naphthyl, and thé

like, ~.

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~L~73Zt)7 Further, the cyclopentadienyl moiety of the above-described metal-containing compounds can be directly bonded with at least one fused ring structure, thereby providin~ an organic ring-containing cyclopentadienyl moiety. The organic ring structure fused with the cyclopentadienyl moiety can be alicyclic or aromati1. When this structure is alicyclic, there is provided a leries of compounds which can be represented by the general formula ~CH2~ D

wherein a and b can be the same or different and are small whole integers including zero and excluding one, wherein n, p and M are as described heretoore, and wherein R5 is selected from the class consisting of hydrogen and monovalent essentially hydrocarbon radicals, as described heretofore.
Thus, when a is zero, each of the carbon atoms designated as 2 and 3 have attached thereto a monovalent radical selected ~rom the class consisting of hydrogen and essentially hydro-carbon radicals. Furthermore, the monovalent radicals so attached can be the same or different. The same discretion applies to each o the carbon atoms designated as 4 and 5 when b is zero.
In an additional embodiment, the present metal-containing compounds are represented by the following structure ~'` .

[Rl A~n~(CO)p w~erein A is a cyclomatic hydrocarbon radical having from 5 ~ _ :

... . ~, . - . .............. ., , : : - . . :
, . . . : .. , . . - , :~1373~37 - to about 25 caxbon a.toms which embodies a gro~p of 5 carbons having the con~iguration found in cyclopentadielle, Rl is a monovalent essentially hydrocarbon radical as defined hereto-fore and M, n and p are as defined hereinbefore:, said compounds.
being further characterized in that the cyelomatic hydrocarbon radical is bonded to the metal by earbon-to-metal bonds through carbons o~ the eyelopentad:ienyl group. In a preferred embodiment, as before, n is equal to 1 and p is equal to 3.
Illustrative examples of the presently useful metal-eontaining compounds include the following: bis-cyclopentadienyl manganese, cyclopentadienyl manganese triearbonyl, bis (2-methyl-eyelopentadienyl) manganese, 2-methyl-eyclopentadienyl manganese triearbonyl, bis-(3~ethyl.-eycIopentadienyl~ manganese, 3-ethyl-eyelopentadienyl manganese triearbonyl, bis-(4-n-propyl-eyelopenta-dienyl) manganese, 4-n-propyl-cyclopentadienyl manganese triearbonyl, `
bis-(5-isopropyl-eyelopentadienyl) manganese, 5-isopropyl-eyelopentadienyl manganese tricarbonyl, bis-~2,3-di-n-butyl-; eyelopentadienyl) manganese, 2,3-di n-butyl cyclopentadienyl . manganese triearbonyl, bis-(2,4-di-see-butyl-eyelopentadienyl) manganese r 2,4-di-see-butyl-eyelopentadienyl manganese tri-earbonyl, bis-~2,5-di-tert-butyl-eyelopentadienyl) manganese, 2,5-di-tert-butylcyelopentadlenyl manganese triearbonyl, bis-(2-phenyl-eyelopentadienyl~ manganese, 2-phenyl-eyelopent~dienyl manyanese triearbonyl, bis-(4-(a~naphthyl~-eyelopentadienyl7 manganese, 4-~a-naphthyl)-eyelopentadienyl manganese triearbonyl, bis-(3-benzyl-cyelopentadienyl~ manganese, 3-benzyl-eyelopenta-dienyl manganese tricarbonyl, bis-(4-~a-phenylethyl)-eyelopenta-; dienyl) manganese, 4-(~-phenylethyl)-eyelopentadienyl manganese triearbonyl, bis-~3-(~-phenylethyl-cyelopentadienyl)manganese, . ! .
'~

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.' ~1 ~73f~7 3~ phenyleth~ cyclol~entadi~nyl) manganese tricarbonyl, bis-(3,4-di-(a-phenyl-butyl)-cyclopentadieny1) mang~nesa, 3,4-di-(~phenyl-butyl)-cyclopentadienyl manganese tricarbonyl, bis-(2-benzyl-cyclopentadienyl) manganese, 2-benzyl-cyclopen-tadienyl manganese tricarbonyl, bis-(3-benzyl-cyclopentadienyl) manganese, 3-ben2yl-cyclopentadienyl manganese tricarbonyl, bis-(3-o-tolyl-cyclopentadi~nyl) manganese, 3-o-tolyl-cyclopenta-dienyl manganese tricarbonyl, bis-(4-m-tolyl-cyclopentadienyl) manganese, ~-m-tolyl-cyclopentadienyl manganese tricarbonyl, bis-(3-p tolyl-cyclopentadienyl) manganese, 3-p-tolyl-cyclopenta-dienyl manganese tricarbonyl, bis-(3-o-ethyl-phenyl-cyclopentadienyl) manganese, 3-o-ethylpnenyl-cyclopentadienyl manganese tricarbonyl, bis-~2-m-ethylphenyl-cyclopentadienyl) manganese, 2-m-ethylphenyl-: cyclopentadienyl manganese tricarbonyl, bis~(4,5,6,7-tetra~
hydroindenyl) manganese, 4,5,6,7-tetrahydroindenyl manganese tricarbonyl, bis-(1,2,3,4,5,6,7,8,~octa-hydrofluorenyl) manganese, 1,2,3,4,5,6,7,8,-octahydrofluorenyl manganese tricarbonyl, bis-(3-methyl-4,5-,6,7,tetra~lydroindenyl) manganese, 3-methyl-4,5,6,7, tetrahydroindenyl manganese tricarbonyl, bis-(indenyl) manganese, bis-(4,7-dimethyl indenyl) manganese, 4,7-dimethyl indenyl man-ganese tricarbonyl, bis-(4,phenyl fluorenyl) manganese, 4,phenyl fluorenyl manganese tricarbonyl J bis-(3~methyl-4,6-diethyl indenyl) manganese, 3-methyl-4,6-diethyl indenyl manganese tricarbonyl, indenyl manganese tricarbonyl, bis-fluorenyl man- . :
ganese, fluorenyl manganese tricarbonyl, bis-(butyl-indenyl) manganese, butyl-indenyl manganese tricarbonyl, bis-(sec-butyl- :
fluorenyl) manganese, sec-butyl-fluorenyl manganese tricarbonyl, bis-(isobutyl-3-methyl-cyclopentadienyl) mangane.se, isobutyl-3-methyl-cyclopentadienyl manganese tricarbonyl, bi.s~(t-butyl-5- ::
30 o-tolyl-fluorenyl) manganese, t-butyl-5-o~-tolyl-fluor2nyl . . .

, ~9~
;

~1~7~f~

manganese tricarbon~l, bis-(ethyl-di(cyclopentadienyl) manganese, ethyl-di(cyclopentadienyl) manganese tricarbonyl, bis-(di-ethyl-indenyl) manganese, di-ethyl-indenyl manganese tricarbonyl, methylpropionyl cyclopentadienyl manganese tricarbonyl, acetyl cyclopentadienyl manganese tricarbonyl, benzoyl cyclopentadienyl manganese tricarbonyl, 3~methyl-5-ethylbenzoyl-isopropyl cyclo-pentadienyl manganese tricarbonyl, ~ diethylpropionyl;ndenyl manganese tricarbonyl, benzylacetyl cyclopentadienyl manganese tricarbonyl and 3-n-propyl-6-ethylbenxoyl cyclopentadienyl manganese tricarbonyl. Corresponding compounds of technetium and rhenium are also sui'cable for use in the present invention.
The aliphatic alcohols useful in the present invention often contain from 1 to about 8, preferably from 1 to about 4, carbon atoms per molecule. Preferably, the alcohols are mono-hydroxy alcohols. Such alcohols are conventional and well known in the art. Included among these alcohols are methyl alcohol, ethyl alcohol, n propyl alconol~ iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, amyl alcohols, hexyl alcohols, heptyl alcohols, octyl alcohols and mixtures thereof. In a particularly preferred embodiment ; of the present invention, t-butyl alcohol is employed. The alcohol is preferably included in an amount which is soluble in the present fuel composition at xoom temperature, e.g., about 50F. to about 80F. Preferably, the alcohol comprises from about 0.001% to about 20%, more preferably from about 0.5% to about 12~, by volume of the total fuel composition.
Water is an additional essen~ial component of the present compositions. Preferably, the water is present in a amount which is soluble in the present compositions at room temperature. For example, water preferably comprises from , 3~'Z637 about 0.001% to about 0.2~, more preferably 0.005% to about 0.1~, by volume of the total fuel composition. Additionall~, the present compositions may include a water co-solvent so as to so]ubilize the water in the present compositions. Specific examples of such water co-solvents are conventional and well known in the art. Such co-solvents include, for example, glycols, aldehydes, amides and diamines containing from 1 to about carbon atoms per molecules. Illustrative examples include ethylene glycol, formaldehyde, formamide, meta-phenylene diamine and the like.
The present compositions are useful in fu~ling an internal combustion engine and provide cutstanding henefits, e.g., reduced tendency of the engine to knock during operation.
Conventionally, a fuel composition, such as the present compositions is combined with air in at least one carburetor and combusted in the combustion chamber or chamhers of an internal combustion engine. Since it is preferred that the present fuel compositions be available for transport to the carburetor in a sing].e stable liquid phase, it is preferred that only a single injection means to be used to feed the compositions to the carburetor. ~Iowever, it is also within the scope of the present invention that one or more of the essential components of the present compositions be fed to the engine by separate injection means. In any event, at ; combustion, the present fuel compositions achieve outstanding :. ..,,:, :
benefits, e.g., improved engine anti knock properties.
The following examples illust~ate more clearly the method of the present invention~ However, these illustrations ar~ not to be interpreted as specific llmitations on this invention.

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~6~7~C)7 EXAMPL~S
These examples illustrate certain of the benefits of the present invention.
A number of fuel compositions were prepared with sufficient blending to insure uniform composition. Each of these compositions included a base gasoline having the ~ollowing average characteristics:
Mass Spec Type Analysis Vol.

Paraffins 70 ! 10 Naphthenes 10 Arom~ics 20 ASTM (D~86) Initial 90~
10~ 125 20% 145 ~0% 160 60~ 230 80% 290 i EP 400 Certain of these fuel compositions, as shown in Table I, included one or more of the following components:
A. A commercially availa~le manganese-containing additive system capable of increasing the octane number rating of ~uel compositions. The primary m~nganese-containing compound in this additive system is cyclopentadienyl manganese tricarbonyl.

B~ Tertiary butyl alcohol, designated in Table I
l as "TBA".

C. Water 3~ Each of the compositions thus prepared was tested for octane number by both motor (ASTM D-357-~47) and research methods (ASTM D-908-47T). ~esults of these octane number determinations and certain other calculations are summarized in Table I. ~-.

,, , . . . ~ . ~

m~
~) 13 h ~
Z~ ~ . ~ . ' ~ 3 o c o o o W ~ w ~ ~ ~ ~ + + + +
l e ~ ~ e z 3 u ~c 6 #
~ O ~ # ~U l¢ W V ~ N N
a~ # ~ m ~ ~ ~ J ~ o O O o ~ O
X SJ ~ # O O # ~
~a _ ~ D~ I`
E C4 .o o ~: e ~ ~ 9 o ~ ~D
X ~ J W N ~) u 3 ~ o ~1 J~ b~ ~ ,~ J .c X~ l3 o E ~ O~ ~j 8 E N ~ t'l ~ ~ ~ E

I N 1~ ~ O E u~ N C~

0 t: E G ~ r ~ , ~a o E m ~~ u) ~ o c~ Q) C) ~i rJ
N ~ ~ ;~ N C~ ~ O _i N Irl ~) ~1 ~ ~ ~a ~ .
0 ~
~rO ~ ~ ~ a ~ ~ :

5 1~ ~ o ~ o ~ N 0~ I Q a u~ ~:
O Cl 0 ~ N 1~) 1~ ~ ~ 11~ N N N ~ N N ~ 1' ~ ~ ~r ~ C D~ 3 ~ C
X O Z _ m m co o~ CD CD ~o co ~ o~ cc> 0 co C~ # .k ~ OIt~ o ~r~ N ~ ~)O ~ S E e Q _~ N ~ 1~ O N r~ ~ _i ~ ~ ~ ~ ~ ~ y~ n- ~: .C
: ' O ~r; Z ~4 O~ ~ ~ O~ V
:, ~ c l o _1 0 0 0 ,~ ~ O E '~ ~c~ ~ g O O O O O ~, O O O O O O ~ O O O O O C~ O ~ ~ Z ~ " ' rJ.rl E~ ~ ~
~ ~ v _I u~ o u~ O u~ o u~ In O U~ n o 4~ S ~
E I I N ~D N O ~0 N O O ~ Otl ~D N ~1 ~ 0 0 ~ ~

,;~1 OP ' ' dP aP dP Ul O Ir~ ~ Ul O O O _I N ~.
o ~ o o ~ ~ ~
:tl ~ . . . " ,' .

~ _l~J _ ~,.:
r-l N ~ I~ 0~ O~ O ~1 ~

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~73Z~37 The results summarizecl in Table I clearly demonstrate the outstanding im~rovement in octane number rating of the present fuel compositions. For example, compositions which include both manyanese-containing compound and a combination of tertiary butyl alcohol and water (compositions 13 to 18) have motor method octane number rat:ings from .3 to .8 of a number higher than the expected simple additive effects oi each of these components separately. These results are additionally surprising in view of other data (compositions 1 to 6) which indicate that no discernable octane number improvement, other than the expected simple additive effect, is provided from an additive system including manganese-containing compound and t-butyl alcohol without water.
In short, these data make clear that a fuel composition including at least one compound of a metal selected from the group consisting of manganese, technetium, rhenium, and mixtures thereof, a minor amount of at least one aliphatic alcohol containing from 1 to about 8 carbon :
atoms and a minor amount of water provide outstandingly improved octane number ratings.
While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the followillg claims.

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Claims (16)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

1. A fuel composition comprising a major amount of hydrocarbons boiling in the gasoline boiling range; a minor amount capable of improving the octane rating of said composition of at least one hydrocarbon-soluble compound of a metal selected from the group consisting of manganese, technetium, rhenium and mixtures thereof; a minor amount of at least one aliphatic alcohol containing from 1 to about 8 carbon atoms and a minor amount of water, wherein said compound and the combination of said alcohol and said water are present in mutually activating amounts to improve the octane number rating of said fuel composition.

2. The composition of claim 1 wherein said metal is present in said composition in an amount from about 0.01 grams./
gal. to about 10 grams./gal., calculated as elemental metal, said alcohol is present in an amount from about 0.001% to about 20%
by volume of said composition, and said water is present in an amount from about 0.001% to about 0.2% by volume or said composition.

3. The composition of claim 2 wherein said metal is manganese.

4. The composition of claim 3 wherein said alcohol is monohydroxy.

5. The composition of claim 4 wherein said alcohol contains from 1 to about 4 carbon atoms per molecule.

6. The composition of claim 5 wherein said manganese is present in said composition in an amount from about 0.05 grams./
gal. to about 6 grams./gal., calculated as elemental manganese, said alcohol is present in an amount from about 0.5% to about 12% by volume of said composition and said water is present in an amount from about o.005% to about 0.1% by volume of said composition.

7. The composition of claim 6 wherein said alcohol is tertiary butyl alcohol.

8. The composition of claim 7 wherein said compound of manganese includes a group of 5 carbon atoms having the configuration found in cyclopentadiene.

9. The composition of claim 8 wherein said compound of manganese is cycolpentadienyl manganese tricarbonyl.

10. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 1.

11. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 2.

12. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 3.

13. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 6.

14. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 7.

15. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 8.

16. In a method for operating an internal combustion engine, the improvement which comprises fueling said engine with the composition of claim 9.