Patent Description:
Fuel additives are commonly added to hydrocarbon fuels, such as gasoline and diesel, to provide a wide variety of known benefits, such to boost octane and reduce engine knock, reduce formation and buildup of deposits, clean fuel injectors, improve fuel combustion efficiency, maintain flow of diesel during cold weather, and disperse water.

Fuel additives typically include a fuel compatible solvent, such as petroleum distillates, alcohol, toluene, xylene, or trimethyl benzene, and may include one or more other active agents in relatively small quantities, such as antioxidants.

Recently, fuel additives have been proposed which contain nanoparticles made from boron (B), boron/rare earth oxides, boron/iron composites (B/Fe), cerium oxide (CeO<NUM>), doped cerium oxide, aluminum (Al), magnesium-aluminum, cobalt oxide (Co<NUM>O<NUM>), or iron oxides. A common feature of such nanoparticles is that they are made from relatively low cost metals that are easily oxidized into ionic form. Notwithstanding the foregoing, fuel additives containing nanoparticles have yet to attain market acceptance and have been viewed with suspicion by environmentalists and the EPA in view of the generally highly reactive nature of nanoparticles, particularly metal compounds containing metal ions or metals that can easily oxidize during combustion.

<CIT> discloses gasoline additives for catalytic control of emissions from combustion engines. Such additives are in the form of a solid briquette deposited in a gas or a filter placed in a gas line and contain metal compounds, including noble metal compounds such as a combination of X<NUM> PtCl<NUM>, RhCl<NUM> and XReO<NUM>, where X = K, Rh or Cs, which are formulated to slowly dissolve into gasoline. Following combustion, such compounds are carried by exhaust gases through the exhaust system and deposited on exhaust system surfaces to provide catalyst sites for conversion of toxic emissions.

<CIT> discloses nanoparticles with spherical shape for fuel additives in the context of fuel economy.

Also <CIT> discloses nano-sized zinc particles selected form nano-sized metallic zinc particles and nano-sized zinc oxide particles in the context of improving fuel economy. The particles have, for instance, a spherical shape.

Noticeably absent in the art is any known or proposed way to manufacture fuel additives containing nanoparticles made from nonionic, ground state metals or metal mixtures or alloys, such as noble metals, transition metals, or rare earth metals.

Disclosed herein are fuel additive compositions and related methods of manufacturing and using fuel additive compositions as claimed in claims <NUM> to <NUM>. The fuel additive compositions can be used as an additive for any hydrocarbon fuel, including, but not limited to, gasoline, diesel, jet fuel, propane, butane, white gas, coal, synthetically derived fuels, fuel oil, and bunker oil.

The fuel additive composition of the invention comprises: (<NUM>) a carrier that is readily miscible in a hydrocarbon fuel; and (<NUM>) a plurality of non-ionic solid spherical-shaped metal nanoparticles.

According to some embodiments, the fuel additive composition may comprise: (<NUM>) a hydrocarbon soluble carrier; and (<NUM>) a plurality of spherical-shaped metal nanoparticles comprising at least one nonionic, ground state metal selected from the group consisting of gold, platinum, silver, palladium, rhodium, osmium, ruthenium, rhodium, rhenium, molybdenum, copper, iron, nickel, tin, beryllium, cobalt, antimony, chromium, manganese, zirconium, tin, zinc, tungsten, titanium, vanadium, lanthanum, cerium, heterogeneous mixtures thereof, and alloys thereof.

According to some embodiments, a method of treating a hydrocarbon fuel comprising adding a fuel additive composition as disclosed herein to the hydrocarbon fuel, preferably an amount of fuel additive composition to yield a treated hydrocarbon fuel containing from <NUM> parts per billion ("ppb") to <NUM> ppm of metal nanoparticles by weight, or <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppb of metal nanoparticles by weight. The hydrocarbon fuel can be treated while inside a fuel tank of a vehicle or motor. Alternatively, the hydrocarbon fuel can be treated while contained within a large storage or dispensing vessel, an example of which is a storage tank at a fuel filling facility.

A method of manufacturing a fuel additive composition may comprise combining (<NUM>) a plurality of nonionic metal nanoparticles selected from the group consisting of solid spherical-shaped metal nanoparticles and coral-shaped metal nanoparticles in which each coral-shaped metal nanoparticle has a non-uniform cross section and a globular structure formed by multiple, non-linear strands joined together without right angles and (<NUM>) a carrier that is soluble or readily miscible in a hydrocarbon fuel.

The fuel additive compositions disclosed herein can provide the following benefits, including but not limited to: improved fuel efficiency, reduced emissions (e.g., unburned hydrocarbons, soot, and/or carbon monoxide), corrosion resistance, engine knock reduction, improved valve performance, and lower engine temperatures.

These and other advantages and features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention.

Disclosed herein are fuel additive compositions that provide metal nanoparticles that are readily dispersible into a hydrocarbon fuel. The metal nanoparticles are dispersed within or contained on or within in a carrier that is readily miscible in a hydrocarbon fuel. The carrier can be a liquid, gel or solid. The fuel additive compositions can be formulated for use as an additive for any hydrocarbon fuel, including, but not limited to, gasoline, diesel, jet fuel, propane, butane, white gas, coal, synthetically derived fuels, fuel oil, and bunker oil.

The metal nanoparticles consist essentially of nonionic spherical-shaped metal nanoparticles.

Nonionic metal nanoparticles useful for making fuel additive compositions comprise spherical nanoparticles, preferably spherical-shaped metal nanoparticles having a solid core. The term "spherical-shaped metal nanoparticles" refers to nanoparticles that are made from one or more metals, preferably nonionic, ground state metals, having only internal bond angles and no external edges or bond angles. In this way, the spherical nanoparticles are highly resistant to ionization, highly stable, and highly resistance to agglomeration. Such nanoparticles can exhibit a high ξ-potential, which permits the spherical nanoparticles to remain dispersed within a polar solvent without a surfactant, which is a surprising and expected result.

The spherical-shaped metal nanoparticles have a diameter of about <NUM> or less, preferably about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, or about <NUM> or less. The spherical-shaped nanoparticles have a particle size distribution such that at least <NUM>% of the nanoparticles have a diameter within <NUM>% of the mean diameter of the nanoparticles. Spherical-shaped nanoparticles can have a mean particle size and at least <NUM>% of the nanoparticles have a particle size that is within ± <NUM> of the mean diameter, ± <NUM> of the mean diameter, or ±<NUM> of the mean diameter. In some embodiments, spherical-shaped nanoparticles can have a ξ-potential of at least <NUM> mV, preferably at least about <NUM> mV, more preferably at least about <NUM> mV, even more preferably at least about <NUM> mV, and most preferably at least about <NUM> mV.

Examples of methods and systems for manufacturing spherical-shaped nanoparticles are disclosed in <CIT> to William Niedermeyer (the "Niedermeyer Publication"). <FIG> is a transmission electron microscope image (TEM) of exemplary spherical-shaped nanoparticles made using the methods and systems of the Niedermeyer Publication. The illustrated nanoparticles are spherical-shaped silver (Ag) nanoparticles of substantially uniform size, with a mean diameter of about <NUM> and a narrow particle size distribution. In some embodiments, spherical-shaped nanoparticles can have a solid core rather than being hollow, as is the case with conventional metal nanoparticles, which are usually formed on the surfaces of non-metallic seed nanoparticles (e.g., silica), which are thereafter removed to yield hollow nanospheres.

The non-ionic spherical-shaped metal nanoparticles, may comprise any desired metal, mixture of metals, or metal alloy, including at least one of silver, gold, platinum, palladium, rhodium, osmium, ruthenium, rhodium, rhenium, molybdenum, copper, iron, nickel, tin, beryllium, cobalt, antimony, chromium, manganese, zirconium, tin, zinc, tungsten, titanium, vanadium, lanthanum, cerium, heterogeneous mixtures thereof, or alloys thereof.

The fuel additive composition also includes a carrier for delivering the metal nanoparticles to a hydrocarbon fuel into which they will be mixed. The carrier can be a liquid, gel, or solid. Some carriers may be more suitable than others depending on the hydrocarbon fuel into which the fuel additive composition is to be added. For example, the solubility characteristics of the carrier can be selected to maximize or otherwise provide a desired solubility with the hydrocarbon fuel. In many cases it may be desirable for the carrier material(s) to be readily miscible or soluble within the hydrocarbon fuel being treated. Some carriers can be soluble in virtually any hydrocarbon fuel, while others can be more soluble in some fuels and less soluble in others. In the case of solid fuels, such as coal, charcoal, or biomass, it may not be necessary or desirable for the carrier to be soluble in the fuel. If applied to a solid fuel, for example, it may or may not be desirable for the carrier to evaporate.

Examples of carrier liquids that can be used to formulate fuel oil compositions as disclosed herein include, but are not limited to, vegetable oils, nut oils, triglycerides, petroleum distillates, alcohols, ketones, esters, ethers, organic solvents, methanol, ethanol, isopropyl alcohol, other lower alcohols, glycols, and surfactants.

Gels known in the art can be used as carriers, such as gels containing one or more of the foregoing liquid components together with known gelling agents. As compared to a liquid additive, gel additives can be more easily enclosed or encapsulated by a solid enclosure to form a pre-measured packet that can be used to treat a specific quantity of fuel. In addition, while gel additives can be formulated to dissolve into many different types of hydrocarbon fuels, they may be desirable in the case of more viscous fuels, such as some types of fuel oil and bunker oil, where a mixing apparatus is used to mix the viscous fuel and fuel additive together (e.g., because it is sometimes easier to mix two materials having similar viscosities compared to materials having greatly differing viscosities).

Solid carriers can be used for different reasons, such as to enclose nanoparticles as a pre-measured tablet to treat a specific quantity of fuel. A solid carrier can also be used to enclose a fuel additive composition containing nanoparticles and a liquid or gel carrier. In many cases, it will be advantageous for the solid carrier to be readily dissolvable in the hydrocarbon fuel. Examples of solid carriers include, but are not limited to, polymers, rubbers, elastomers, foams, and gums. Depending on the solvent characteristics of the fuel to be treated and the desired level of solubility of the carrier, one of skill in the art can select an appropriate solid carrier material.

In some embodiment, a fuel additive composition can be formulated so that the metal nanoparticles are included in a concentration so that a measured quantity of the fuel additive composition, when mixed with a given quantity of hydrocarbon fuel, will yield a treated hydrocarbon fuel containing a predetermined concentration or quantity of metal nanoparticles. By way of example, the metal nanoparticles can be included in a concentration so that a measured or predetermined quantity of the fuel additive composition, when mixed with the given quantity of hydrocarbon fuel, will yield a treated fuel containing from <NUM> parts per billion ("ppb") to <NUM> ppm of metal nanoparticles by weight, or <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppb of metal nanoparticles by weight.

The fuel additive composition itself will have a higher concentration of nanoparticles that become diluted when mixed with the fuel. Depending on the type of fuel being treated, the nature of the nanoparticles being added, and the type of carrier being used, the fuel additive composition may contain about <NUM> ppm to about <NUM> ppm of metal nanoparticles by weight, or about <NUM> ppm to about <NUM> ppm, or about <NUM> ppm to about <NUM> ppm of metal nanoparticles by weight.

In some embodiments, the fuel additive composition can be provided in a pre-dosed quantity formulated to treat from about <NUM> gallons (<NUM> liters) to about <NUM> gallons (<NUM> liters) of hydrocarbon fuel, or <NUM> gallons (<NUM> liters) to about <NUM> gallons (<NUM> liters) of hydrocarbon fuel.

In some embodiments, the fuel additive composition can also include one or more optional components to provide desired properties, including, but not limited to detergents, octane boosters, corrosion inhibitors, anti-knock agents, or valve cleaners.

The carrier may also function as, or may include, a stabilizing agent. For example, in some embodiments it may be desirable to have different specifically sized nanoparticles within the same solution to take advantage of each of the different properties and effects of the different particles. However, when differently sized particles are mixed into a single solution, the overall long-term stability of these particles within that single solution may be substantially diminished as a result of unequal forces exerted on the various particles causing eventual agglomeration of the particles. This phenomenon may become even more pronounced when that solution is either heated or cooled significantly above or below standard room temperature conditions.

Examples of stabilizing agents include alcohols (e.g., ethanol, propanol, butanol, etc.), polyphenols, mono-glycerides, di-glycerides, or triglycerides, oils, other terpenes, amine compounds (e.g., mono-, di-, or tri-ethanol amine), liposomes, other emulsions, and other polymers.

Stabilizing agents are preferably dissolved within a separate carrier in the micro- to milli- molar concentration range with the upper range limitation typically being constrained not by efficacy but by product cost.

These various stabilizing agents have the capacity to hold at least two differently sized and/or shaped nanoparticles in suspension and deliver these nanoparticles into the treatment area of a plant or plant part without so powerfully retaining the nanoparticles so as to diminish the antimicrobial properties of the nanoparticles.

In some embodiments, a method of treating a hydrocarbon fuel comprises: (<NUM>) obtaining a fuel additive composition as disclosed herein: and (<NUM>) adding the fuel additive composition to the hydrocarbon fuel. This may involve, for example, pouring, mixing, spray application, or dropping a solid form into a tank of fuel. The fuel additive composition is added in an amount to yield a treated hydrocarbon fuel containing from <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppm, or <NUM> ppb to <NUM> ppb of metal nanoparticles by weight.

In the case of gasoline or diesel powered vehicles, an exemplary fuel additive composition can be provided as a liquid or gel which is added in an amount of about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, for every <NUM> gallons (<NUM> liters) of fuel. The fuel additive composition can be provided inside a standard fuel additive container, such as those having a generally enlarged lower tank portion and a narrow, elongated neck portion to facilitate insertion into the opening of a fuel tank.

Alternatively, the fuel additive composition may contain a solid carrier, wherein the fuel is treated by causing or allowing the hydrocarbon fuel to dissolve the solid carrier in order to release and disperse the metal nanoparticles.

A method of manufacturing a fuel additive composition, may comprise combining: (<NUM>) a plurality of metal nanoparticles selected from the group consisting of solid spherical-shaped metal nanoparticles and/or coral-shaped metal nanoparticles in which each coral-shaped metal nanoparticle has a non-uniform cross section and a globular structure formed by multiple, non-linear strands joined together without right angles; and (<NUM>) a carrier that is readily miscible in a hydrocarbon fuel. The carrier can have any desired physical form, such as a liquid, gel or solid.

<NUM> ppm of spherical-shaped gold nanoparticles having a mean particle size of about <NUM>, with at least <NUM>% of the gold nanoparticles having a particle size within <NUM>% or less of the mean particle size are placed in a carrier to form a fuel additive.

A treated gasoline fuel contained <NUM> ppb of spherical-shaped gold (Au) nanoparticles <NUM>-<NUM> in diameter, which were delivered into the gasoline using a triglyceride (fractionated coconut oil) carrier. Treating the gasoline in this manner produced a <NUM>% increase in fuel efficiency in a <NUM> hp Ford Mustang engine.

Claim 1:
A fuel additive composition comprising:
a carrier that is readily miscible in a hydrocarbon fuel, such as a carrier that is a liquid, a gel or solid; and
a plurality of metal nanoparticles consisting essentially of:
nonionic, solid spherical-shaped metal nanoparticles having no external bond angles or edges, and having a diameter of <NUM> or less in which at least <NUM>% of the spherical-shaped nanoparticles have a diameter within <NUM>% of the mean diameter,
wherein the fuel additive composition is in a pre-dosed quantity formulated so as to treat from <NUM> liters to <NUM> liters of hydrocarbon fuel and provide a concentration of the metal nanoparticles in the hydrocarbon fuel when mixed therein of <NUM> ppb to <NUM> ppm by weight.