Fuel additive

Performance is improved and wear of a combustion engine is decreased by adding a solution of a compound in a combustible diluent such as methanol. The compound is the reaction product in diluent of a fluoralkyl-arylamine such as trifluoro-m-toluidine and a halide salt such as boron trifluoride. The amine group is polar and can bind with water and/or provide detergency properties. The polar group can bind to metal surfaces such as engine parts to form a highly ordered film with the low friction, non-reactive fluoralkyl groups oriented to the outside. This film protects the surface from corrosion or wear and lowers the friction between moving parts.

TECHNICAL FIELD 
The present invention relates to an additive for liquid hydrocarbon fuels 
and, more particularly, this invention relates to an additive for gasoline 
or diesel fuel that improves performance while reducing emissions from an 
engine. 
BACKGROUND ART 
The consumption of oil and gas represents about 80 percent of the 
consumption of fossil fuels in the United States. At the present time, 
about onehalf of the electric power is generated from natural gas and 
petroleum. Petroleum resources in this country are being depleted and the 
United States is dependent on politically unstable and unreliable foreign 
governments to supply its energy needs. Moreover, the combusion of liquid 
fuels results in the generation of hydrocarbon pollutants that must be 
treated before exhaust to the atmosphere. The generation of large amounts 
of carbon dioxide as a byproduct of the combustion of fossil fuels may 
cause the so-called greenhouse effect, raising the average temperature in 
the atmosphere to a level high enough to melt the polar ice caps. 
Fuels other than liquid and gaseous hydrocarbons, such as nuclear or 
hydrogen, are being investigated as are power sources other than internal 
combustion engines, such as fuel cells, photovoltaic cells or electric 
storage batteries. However, consumers are accustomed to using liquid fuels 
and the supply, distribution, power generation and marketing 
infrastructure are already in place. The demand for liquid hydrocarbon 
fuels for power generation and transportation is expected to double by the 
year 2000. 
Costs of refining gasoline have increased recently since octane boosters 
such as tetraethyl lead can no longer be utilized in recent automobiles 
because lead compounds poison the platinum catalysts used in the pollution 
control reaction and the emission of lead in the exhaust is believed to be 
a toxic waste product. Therefore, more refining is necessary to produce 
the higher octane gasoline. The presence of tetraethyl lead has 
contributed to longer engine life since the combusion residue remained in 
the cylinder as a lubricating film which greatly extended the life of 
engine parts such as valves and rings. 
STATEMENT OF INVENTION 
It was believed that the engine life and possibly performance would be 
enhanced by adding a material to the engine surfaces. It was surprisingly 
discovered that the additive of the invention not only improved 
performance but also caused a substantial reduction in both hydrocarbon 
and carbon monoxide emissions. 
The fuel additive of the invention is the reaction product of a halide such 
as boron trifluoride and a polyhalo-substituted alkaryl amine. The 
reaction product has both a highly polar, hydrophilic side chain and a 
non-polar, oleophilic parent nucleus. This type of molecule can attach to 
metal surfaces through the polar side chain to form a lubricating film. 
The molecule can act an emulsifier to tie up the water present in the fuel 
or can form closed vesicles which encapsulate water to dehydrate the fuel. 
The additive, and especially the boron-trifluoride component, a known 
catalyst, may contribute to more complete or efficient combusion of the 
fuel to reduce the level of hydrocarbon and carbon monoxide gasses in the 
engine's exhaust. 
Fuel economy improvement in a wide variety of test vehicles showed a mean 
improvement of over 10 percent. Hydrocarbon emissions were reduced more 
than 90 percent of California standards. Emissions were reduced more than 
95 percent in the case of carbon monoxide. The low-friction coating on the 
surface of engine parts reduces wear while promoting more complete 
combustion which augments energy derived from the fuel. Maintenance costs 
are lowered while performance is improved. Engines operating on fuel 
containing the additive of the invention run smoother and quieter. The 
additive treated fuel is also found to provide cleaning of carburetor and 
spark plug surfaces to remove carbon deposits. 
Gasoline is saved and starting is improved. Moisture is removed from the 
fuel. Valve and valve seats are cleaned of deposits and exhaust systems 
are also found to be freer of deposits. The additive of the invention is 
absent heavy metals, such as lead that can poison catalytic pollution 
control equipment. None of the test vehicles shows any adverse effect 
operating with fuel containing the invention additive. The film forming 
properties of the additive of the invention will also prevent and inhibit 
corrosion and abrasion of vital metal surfaces of engine components. 
These and many other features and attendant advantages of the invention 
will become apparent as the invention becomes better understood by 
reference to the following detailed description when considered in 
conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS 
The additive 10 of the invention as illustrated in FIG. 1 is formed of 
three components. The parent structure 12 is an oleophilic moiety, 
suitably an aromatic group such as benzene. The central structure is 
substituted with a non-polar, low friction group 14, usually a 
perhalocarbon group and a second polar group 16 which may also contribute 
detergent properties 18 to the additive. The polar groups 16 attach to a 
hydrophilic surface 20 such as the metal surfaces of a piston cylinder or 
valves or valve seats forming a monomolecular film 22 havihg a highly 
ordered orientation with the low friction, non-reactive, corrosion 
protecting groups 14 oriented to the outside. This forms a low friction 
sheath which provides lubrication to wearing surface and corrosion 
protection to all covered surfaces. When not attached to a surface, the 
polar groups 16 on the additive molecules 10 can associate with water and 
the detergent groups 18 can function in cleaning and protecting surfaces, 
such as carburetor or valves, removing deposits of resins or other 
residues which can cause engines to miss, run roughly and/or inefficiently 
combust expensive fuel. 
A preferred additive is formed from the reaction of haloalkyl-arylamine and 
a halide salt to form an adduct. Boron, aluminum or titanium salts may be 
utilized, preferably boron trifluoride. Boron trifluoride is most 
conveniently handled as a complex with an ether such as diethylether. 
The preferred haloalkyl-arylamines are trifluoroalkyl substituted pyridines 
which have a relatively high content of available and active fluorine 
atoms for reaction or association with the halide salt. 
Preferred materials are fluoroalkyl-aryl compounds selected from those of 
the formula: 
##STR1## 
where n is an integer from 0 to 4, m is an integer from 1 to 2 and R is 
selected from hydrogen, lower alkyl of 1 to 9 carbon atoms, lower alkanol 
of 1 to 8 carbon atoms and aryl such as phenyl or aralkyl such as benzyl. 
A suitable material is .alpha., .alpha., .alpha.,-trifluoro-m-toluidine. 
Adducts of this nature as coatings for titanium surfaces or as additives 
to electroytic baths are disclosed in my prior U.S. Pat. Nos. 3,992,414, 
3,996,115, 4,004,064, 4,031,027, 4,023,486, Re. 29,852 and Re. 29,739. The 
amino group provides polar properties and the trifluoromethyl group 
provides lubricating properties. 
The halide and aryl amine can be reacted in bulk, in solution or suspension 
in a liquid. Suitable liquid diluents are polychloro substituted 
unsaturated aliphatic compounds such as trichloroethylene, carbon 
tetrachloride, tetrachloroehtylene, difluoro-dichloro-ethylene, 
fluorotrichloroethylene or other terminally halogenated aklenes of 1 to 8 
carbon atoms or alkanols of 1 to 5 carbon atoms. For purposes of a fuel 
additive, it is preferred to use an alkanol since it is known that 
alkanols are compatible with gasoline and have similar combustion 
characteristics in engines. 
The ratio of the ingredients can be varied within wide limits depending on 
the desired characteristics of the additive and the economics of 
maximizing yield. Since the diluent, such as methanol, is readily 
available at low cost, it can predominate in the reaction mixture. 
Satisfactory yields are obtained by including minor amounts of from 0.002 
to 20 parts and preferably about 2 to 5 parts by volume of the other 
ingredients. Though the order of addition is not critical, it is 
preferable to first form a mixture of the diluent and aryl amine before 
adding the halide salt. 
A specific example follows: 
EXAMPLE 1 
A coating was prepared from the following ingredients: 
______________________________________ 
Component Range Amount 
______________________________________ 
Methanol 1-200 600 ml 
Boron trifluoride 
0.0005 to 50 0.2 ml 
etherate (C.sub.2 H.sub.5).sub.2 O.BF.sub.3 
.alpha.,.alpha.,.alpha.,-trifluoro-m 
0.002 to 100 0.4 ml 
toluidine (C.sub.7 H.sub.6 F.sub.3 N) 
______________________________________ 
In my prior patents, the toluidine and halide complex were utilized in 
about equal amounts. In the fuel additive of the invention, the toluidine 
is added in an excess amount, usually at least 50 percent more by volume 
than the metal salt preferably from 1.5 to 3.0 times the amount of the 
salt. The materials are stirred vigorously for about ten minutes. A mild 
exothermic rise in temperature to about 50.degree. C. is observed when the 
reaction is carried out at higher concentrations to form a clear solution 
containing a complex which is believed to have the following structure: 
##STR2## 
The solution was stored in 355 ml (12 oz.) high density polyethylene 
bottles with screw caps. The dosage amount to be added to a vehicle 
depends on the capacity of the fuel tank and the condition, age and 
displacement capacity of the engine. The 12 oz. screw cap bottle is a 
convenient form for adding the additive of the invention to a vehicle and 
has been found effective in vehicles having tanks capable of containing 
from 12 gallons (45.4 l) up to 24 gallons (90.8 l) of gasoline fuel. The 
fuel additive of the invention can be utilized with any hydrocarbon liquid 
fuel such as gasoline, diesel fuel, airplane fuel, jet fuel, boat or 
motorcycle fuels. In engines containing substantial deposits, it may be 
necessary to repeat the fuel treatment two or three times before optimum 
effect is achieved. Performance data indicates the benfits persist long 
after the initial use of the fuel additive. Occasional periodic treatment 
of adding one 12 oz. container of additive to the vehicle fuel tank once 
every fourth tank fill seems to maintain a minimum functional level of 
additive. Performance was improved with either leaded or unleaded 
gasoline. 
The fuel additive of Example 1 was subjected to long term testing in a 
two-year old 1982 Chrysler LeBaron automobile utilized primarily in city 
stop-and-go driving. The vehicle was equipped with a four-cylinder, 
transversely mounted engine and a three-speed automatic front-wheel drive 
transmission. As shown in FIG. 3, the observed reduction in emissions were 
better than 97 percent of California standards for hydrocarbons, and 
better than 99 percent for carbon monoxide. One 12 oz. bottle of fuel 
additive was added to the full twelve gallon capacity fuel tank prior to 
measuring exhaust emissions levels. 
Fuel economy improvements in nine test vehicles participating in 
"real-world" testing of the fuel additive of the invention showed a mean 
increase of 13.2 percent. These vehicles, from a volunteer road test 
fleet, ranged in age from fifteen years to just several months old at the 
time of testing. These included a wide variety of body styles including 
compacts, sedans, trucks and vans, and sports cars. 
In general, the larger eight cylinder engines showed better response in 
fuel economy increases; sometimes as much as 30 percent better. Compacts 
and light trucks usually showed between 2 and 15 percent increase in 
mileage per gallon over pre-additive fuel economy levels. 
Typical gain in fuel economy is illustrated in FIG. 2. A typical gain of 
about 10 percent improvement in fuel economy is experienced with both 
first and second tankfuls of gasoline containing one 12 oz. treatment of 
additive before the maximum level is achieved. This level persists for 
several additional tankfuls while the fuel economy slowly decreases to the 
base, untreated level. 
The additive of the invention can also be provided by addition to the fuel 
at the refinery. In this manner the additive is constantly being dispensed 
into the carburetor and engine. The additive can be added directly to the 
fuel or can be predispersed in methanol or other combustible diluent. Very 
small concentrations can be utilized since the additive is constantly 
injected into the engine with the fuel. As little as 10.sup.-3 grams 
additive per gallon of the fuel need be present, usually from 10.sup.-3 to 
10.sup.-1 grams per gallon. 
The additive of the invention does not poison the platinum catalytic 
converters. However, exhaust emissions of carbon oxides and uncombusted 
hydrocarbons are so low that a catalytic converter may not be needed. 
Comments of drivers of the test fleet vehicles indicate smoother and 
quieter running and acceleration, less dark exhaust, easier engine 
starting even at freezing temperatures, more passing power, less knocking, 
better gas mileage and no more carbon build-up in the exhaust pipe. 
It is to be realized that only preferred embodiments of the invention have 
been described and that numerous substitutions, modifications and 
alterations are permissible without departing from the spirit and scope of 
the invention as defined in the following claims.