Patent Application
20100212221
1. Field of the Disclosure
The present disclosure relates to an additive composition comprising at least one of i) a metal-based particle and ii) an alloy, wherein at least one of i) the particle and ii) the alloy is capped with at least one iii) flame retardant material. By selecting the particular particle and/or alloy based upon its size, shape, and mass, one of ordinary skill in the art can modulate the combustion rate of the fuel.
2. Background of the Disclosure
Fuels are burned in different combustion systems to achieve a certain task. How well the task is achieved depends on many factors, the primary ones being the design of the respective combustion system, and how efficiently the fuel burns to optimize the performance of that combustion system.
Efficient combustion of fuel depends on the fuel quality used. By quality, it is implied how well suited the fuel is to the specific combustion system, both in the short term efficiency, and long term durability of the combustion system. Fuel quality is predominantly a bulk feature of the fuel that is determined by how the fuel is sourced. However, because fuel sources are so variable, fuel additives play a major role in leveling out this variability. More often than not, it is more cost effective to correct a fuel's quality with appropriate additives than through bulk fuel sourcing parameters.
In developing a fuel for combustion systems, the combustion rates are primary considerations. Once the rates are achieved, control of those rates is critical. When energetic functionalities are incorporated in a fuel, then the primary concern is how to modulate the ensuing combustion event by slowing it down to the desired rate. In most cases this rate has to be shaped to meet changing requirements of the combustion system. If the fuel is solid, then combustion modulators for different rates can be partitioned in the fuel bulk to impart their specific effect when the combustion front reaches their location.
For example, a rocket's combustion and acceleration rate must be initially curtailed to prevent excessive heat and its resulting possible damage to the vessel. At a slightly later time or altitude, the rocket's combustion rate can be increased by the diminution of the initial combustion modulator or conversion to an alternative combustion modulator.
Thus, a graph or ratio of the combustion rate compared to the thrust produced by the combustion is different for rockets, missiles and projectiles, such as shells and artillery. And characteristic fuel combustion rates for each of these applications also vary as described in the preceding paragraph. Tailoring the desired combustion rates for each such application is currently problematic.
To slow or modulate combustion rates, additives capable of absorbing free radicals can be necessary. Examples can be found in flame or combustion retardants, also referred to herein as decelerants or modulators. Another class is octane, or “anti-knock” additives for spark ignited engines, such as tetraethyl lead, methyl cyclopentadienyl manganese tricarbonyl (“MMT”), cyclopentadienyl manganese tricarbonyl (“CMT”), ferrocene, alcohols, arylamines, etc. Metallic anti-knock additives are far superior to organics and require orders of magnitude less additive than the organics to achieve the same task. Metallics are added in ppm levels to the fuel whereas organics are in percent amounts.
The physical form of metal-containing additives of most recent interest is the nanoparticle form because of its unique surface to volume ratios and active site numbers and shapes. As is to be expected, there is interest in mixed metal nanoadditves because each metal tends to have specific functions. Therefore, what is needed is an additive composition that can be formulated to modulate fuel combustion rates.
In accordance with the disclosure, there is disclosed herein nanoparticle and nanoalloy compositions of fuel combustion modulators, and methods of applying these modulators to different combustion systems to optimize desired efficiencies.
In an aspect, there is disclosed a fuel additive comprising at least one of: i) a particle(s) or nanoparticle(s) of oxide(s), hydroxide(s), hydrate(s), and/or carbonate(s) selected from the group consisting of: Al, Sb, Mg, Fe, Mo, Zn, Sn, B, Bi, Ca, Li, Na, K, Ba, Mn, Si, Cu, Cd, Co, Ni, Cr, Ti, Ce, and V; and ii) an alloy(s) or nanoalloy(s) containing two or more metals selected from the group consisting of Al, Sb, Mg, Fe, Mo, Zn, Sn, B, Bi, Ca, Li, Na, K, Ba, Mn, Si, Cu, Cd, Co, Ni, Cr, Ti, Ce, and V; wherein at least one of the i) particles or nanoparticles and ii) alloys or nanoalloys can be capped with at least one iii) flame retardant material.
The present disclosure relates to a fuel additive composition comprising at least one of i) a metal-based particle and ii) an alloy, wherein at least one of i) the particle and ii) the alloy is capped with at least one iii) flame retardant material. By selecting the particular particle and/or alloy based upon its size, shape, and mass, one of ordinary skill in the art can modulate the combustion rate of the fuel. In particular, one can modulate fuel combustion rates, such as a solid fuel, by formulating the additive composition with the appropriate additized fuel and combustion modulator in particles and/or alloy compounds.
The current use of metals in combustion systems relies on chemistries fostered by each metal type as dictated by its unique orbital and electronic configuration acting individually. This means that in additives formulated with metal mixtures, at the time of the intended activity, the metals act independently from one another during fuel combustion. In fact, the physics of a combusting charge minimizes the likelihood that a mixed metal additive will locate the different metal atoms within the same and/or desired and/or proper and/or preferred location on the combusting fuel species so that they may act in unison as a single entity.
Combustion modulators disclosed herein can be designed to do this based on: i) metal-based particle, and/or, ii) alloy, and/or, iii) flame retardant material. The core particle or alloy can be fined tuned further to achieve desired modulation rates by size and shape design by the use of an organic capping ligand with a polar heteroatom derived functionality, such as nitrogen (N), phosphorus (P), and other heteroatoms giving rise to polar functional groups, with all polar functional groups collectively designated as “X”. The capping ligand would then be used to provide the final polishing to the additive performance.
In an aspect, the additive composition can comprise at least one of:
wherein at least one of the i) particles or nanoparticies and ii) alloys or nanoalloys can be capped with at least one iii) flame retardant material. The flame retardant material can be selected from the group consisting of polyhalogenated alkyl halides, polyhalogenated aryl halides; alkyl phosphorus-derived oxides, aryl-phosphorus-derived oxides; and ammonia, alkyl amines, and aryl amine.
In an aspect, the i) particle(s) or nanoparticle(s) can be, for example, hydroxides, such as Mg(OH)2, Ti(OH)2, etc.; metal oxides, such as Sb2O3, SnO2, ZnO, MoO3, Fe2O3, CoO, (NH4)4Mo8O26, etc.; hydrates, such as Al2O3.3H2O, Al(OH)3(H2O)x, etc.; and carbonates, such as CaCO3, MgCO3, etc.
In another aspect, the ii) alloy(s) or nanoalloy(s) can be, for example, Al/Sb, Na/B, Zn/B, Na/Sb, Fe/Mn; borates, borate/hydrates, and borate/hydrate/oxides, such as Ba(BO2)2, LiB3O5, 2ZnO.3H2BO3.3.5H2O, Na2B4O7.10H2O, etc.; and antimonates, such as Na3SbO4, LnSbO4, SiSbO4, FeSbO4, TiSbO4, CeSbO4, VSbO4, VMoSbO4, MnVSbO6, CaMnSb4O14, BaSbO5, Ca2O.SbO5, Co2O.Sb2O5, Mg2O.Sb2O4, etc.
In another aspect, the at least one iii) flame retardant material can be a ligand to give compositions “i(R—Xm)n” and/or “ii(R—Xm)n”, where:
i) and ii) are as defined above;
—R—Xm is a functionalized organic moiety with a polar functional group “X” (i.e. phosphite, phosphate, phosphonate, phosphate esters, carboxylate, alkoxylate, halogenate, amine, etc) that can have flame retardant capability and can also enable R—X to function as a capping ligand to prevent agglomerization of (i) and/or (ii);
R is an organic moiety (i.e. alkyl substituted -cyclopentadienyl, -phenyl, -naphthyl, -anthracyl, -alkyl, -alkenyl etc., wherein the alkyl substituent ranges from C1 to C32 carbon length, the actual length being the minimum necessary to impart the respective fuel compatibility to the additive; and
when X is bromine and R contains aromatic rings, then “m” is an integer that ensures perbromination of the aromatic rings in a similar manner to conventional brominated flame retardants, and
“n” is the number of R—Xm ligands necessary to stabilize i) and ii), and is greater than 0, such as from 15-20;
“m” is an integer greater than 1.
In particular, the additive composition could comprise a particle of cerium oxide that has been treated with an alkyl amine and an alloy of SbxZnyBz or AlxSbyZnz that has been treated with a polyhalogenated alkyl halide and an alkyl phosphorus-derived oxide, where x, y and z are independent integers or decimal fractions.
Examples of other embodiments of the present disclosure include:
iv=“i” combinations with alkyl- or aryl-phosphorus-derived oxides
v=“ii” combinations with alkyl- and/or aryl-phosphorus-derived oxides
vi=“iv” combinations with ammonia and/or alkyl- and or aryl-amines
vii=“ii” combinations with polyhalogenated alkyl- and/or aryl-halides
viii=“ii” combinations with alkyl- and/or aryl-phosphorus-derived oxides
ix=“vii” combinations with alkyl- and/or aryl-phosphorus-derived oxides
x=“vii” combinations with ammonia and/or alkyl- and/or aryl-amines, and/or polyamines.
Methods of combustion modulation useful herein include, a) fuel dilution by generation of non-combustible gases, such as, N2, H2O, CO2, HX (X=halogens), SO3, etc., b) cooling endothermic reactions, c) formation of protective layer such as the production of metal oxide coatings, d) condensed phase activity (i.e. charring and cross-linking), e) vapor or gas phase activity (i.e. HX, HX/Sb, P, etc), and f) for metals, the modulation method is by free radical scavenging controls.
Fuel combustion can be modulated by, for example, by fuel dilution through non-combustible gas generation such as N2, HX, CO2, SO3, etc. as demonstrated by the reactions:
In particular, provided herein is a method of modulating fuel combustion by producing fuel dilution by generation of non-combustible gases selected from the group consisting of N2, H2O, CO2, HX, and SO3 said method comprising: a) combining a fuel and a fuel additive as disclosed herein to form a mixture, wherein the additive comprises a material capable of generating, when heated, a non-combustible gas selected from the group consisting of N2, H2O, CO2, HX, and SO3; b) combusting the mixture, thereby generating said non-combustible gas, whereby the fuel in said mixture is diluted.
Moreover, fuel combustion can be modulated by, for example, by cooling endothermic decomposition reactions:
Thus, there is provided herein a method of modulating fuel combustion by producing cooling endothermic reactions, the method comprising: combusting a mixture of fuel and fuel additive as disclosed herein, whereby the fuel additive when heated enters an endothermic reaction, whereby cooling of the fuel combustion occurs.
In addition, fuel composition can be modulated by, for example, forming a protective glassy layer on a fuel:
In another aspect, fuel combustion can be modulated by, for example, condensed phase activity, such as charring and cross linking:
In further aspect, fuel composition can be modulated by, for example, vapor or gas phase activity:
It is envisioned that the disclosed additive composition could cover all different local flame modulation mechanisms. As previously disclosed, modulation of the combustion rates can be achieved by appropriately selecting particles and/or alloys based upon their mass, shape, and size. However, mass, shape, and size are not limiting factors and all variations of these parameters are contemplated for use in the disclosed additive composition. For example, the particle and/or alloy may be formulated in a layered configuration with two different types of compounds, so that the outer surface would combust at a rate that is different from an inner core. Similarly, different additive compositions of this nature may be segregated and stratified in the matrix of a solid fuel such that different combustion modulation rates are sequentially triggered as the fuel burns. Moreover, the particle and/or alloy may be formulated in a particular shape, such as a platelet shape, because this shape provides more active combustion areas through increased surface area as compared to a rod. Further, the particle and/or alloy may be chosen because it is more or less dense and consequently more or less porous.
In an aspect, the additive composition can be formulated so that it provides any desired color flame signature on combustion, which can be particularly useful in flares and fireworks. Furthermore, poly-nitrogen ring structures (such as for example, bistetrazoles and tetrazines) modulate fuel combustion by releasing gaseous nitrogen to slow combustion. These can also impart color to the flame in cases where a visible exhaust signature is desired. These compounds can either be physically mixed with nanoalloy combustion modulators of this disclosure, or be modified to serve a second function of “capping agents” added during nanoalloy syntheses to control particle size. To become capping agents that are also fuel dispersible, a hydrocarbon solubilizing alkyl group of appropriate size (i.e. pentyl, hexyl, octadecanyl, etc) has to be grafted onto these polar hetero-nitrogenated ring structures.
Some examples include:
The metal-based particle and/or alloy compound for use in the disclosed additive composition can be generated either in aqueous media, or organic media.
In an aspect, the particles and/or alloys can, optionally, be coated with an organic capping ligand with a polar heteroatom-derived functionality, such as nitrogen (N), phosphorus (P), and other heteroatoms giving rise to polar functional groups, with all polar functional groups collectively designated as “X”; or otherwise treated with suitable hydrocarbon molecules that render them fuel soluble and/or to prevent agglomeration. For this purpose, they can be comminuted in an organic solvent in the presence of a coating/capping agent which is an organic acid, anhydride or ester or a Lewis base. It has been found that, in this way which involves coating in situ, it is possible to significantly improve the coating of the particle and/or alloy. Further, the resulting combustion modulation product can, in many instances, be used directly without any intermediate step. Thus in some coating procedures it is necessary to dry the coated particle and/or alloy before dispersing it in a hydrocarbon solvent.
The coating agent can suitably be an organic acid, anhydride or ester or a Lewis base. The coating agent can be, for example, an organic carboxylic acid or an anhydride, typically one possessing at least about 5 carbon atoms, for example about 10 to about 30 carbon atoms, for example from about 12 to 18 carbon atoms, such as stearic acid. It will be appreciated that the carbon chain can be saturated or unsaturated, for example ethylenically unsaturated as in oleic acid. Similar comments apply to the anhydrides which can be used. An exemplary anhydride is dodecylsuccinic anhydride. Other organic acids, anhydrides and esters which can be used in the process of the present disclosure include those derived from phosphoric acid and sulphonic acid. The esters are typically aliphatic esters, for example alkyl esters where both the acid and ester parts have from about 4 to about 18 carbon atoms.
Also useful herein as capping agents are the poly-nitrogen molecules described hereinabove and their alkylated derivatives, and other hydrocarbons having a nitrogen-containing polar head group.
Other coating or capping agents which can be used include Lewis bases which possess an aliphatic chain of at least about 5 carbon atoms including mercapto compounds, phosphines, phosphine oxides and amines as well as long chain ethers, diols, esters and aldehydes. Polymeric materials including dendrimers can also be used provided that they possess a hydrophobic chain of at least about 5 carbon atoms and one or more Lewis base groups, as well as mixtures of two or more such acids and/or Lewis bases.
When the additive is to be used in a combustor where the combustion byproducts can attack and destroy the combustor's lining, then the capping or coating agent can in one embodiment be a phosphorus containing ligand.
The coating process can be carried out in an organic solvent. For example, the solvent is non-polar and is also, for example, non-hydrophilic. It can be an aliphatic or an aromatic solvent. Typical examples include toluene, xylene, petrol, diesel fuel, jet fuels, vegetable and/or animal oils, fish oils, as well as heavier fuel oils. Naturally, the organic solvent used should be selected so that it is compatible with the intended end use of the coated particle and/or alloy. The presence of water should be avoided, the use of an anhydride as a coating agent helps to eliminate any water present.
The coating process involves comminuting the alloy so as to prevent any agglomerates from forming. The technique employed should be chosen so that the alloys are adequately wetted by the coating agent and a degree of pressure or shear is desirable. Techniques which can be used for this purpose include high-speed stirring (e.g. at least 500 rpm) or tumbling, the use of a colloid mill, ultrasonics or ball milling. Typically, ball milling can be carried out in a pot where the larger the pot the larger the balls. By way of example, ceramic balls of 7 to 10 mm diameter are suitable when the milling takes place in a 1.25 liter pot. The time required will of course, be dependent on the nature of the alloy but, generally, at least 4 hours is required. Good results can generally be obtained after 24 hours so that the typical time is from about 12 to about 36 hours.
The additive composition of the present disclosure can comprise at least one alloy of two or more metals. As described herein, the alloy is different chemically from any of its constituent metals because it shows a different spectrum in the X-ray diffraction (XRD) than that of the individual constituent metals. In other words, it is not a mixture of different metals, but rather, an alloy of the constituent metals used.
The primary determining factors for activities metals is primarily the type, shape, size, electronic configuration, and energy levels of lowest unoccupied molecular orbitals (LUMO) and highest occupied molecular orbitals (HOMO) made available by the metal to interact with those of the intended substrate species at conditions when these species are to be chemically and physically transformed. These LUMO/HOMO electronic configurations are unique to every metal, hence the innate physics/chemistry uniqueness observed between, for example, Mn and Pt, or Mn and Al, etc.
The disclosed alloy is the result of combining the different constituent metal atoms in the compound. This means that the LUMO/HOMO orbitals of the alloy are hybrids of those characteristic of the respective different metal atoms. Therefore, an alloy ensures that all constituent metals in the alloy particle end up at the same site and act as one, but in the modified i.e., alloy, form. The advantages of an alloy for this purpose would be due to unique modifications imparted to the LUMO/HOMO electronic and orbital configurations of the particles by the mixing of LUMO/HOMO orbitals of the different respective alloy composite metals. The number and shape of active sites would be expected to also change significantly in the alloy composites relative to the number and shape of active sites in equivalent but non-alloy mixtures. This unique orbital and electronic mixing at the LUMO/HOMO orbital level in the alloys is not possible by simply mixing particles of the respective metals in appropriate functional ratios.
An exemplary alloy can be represented by the following generic formula (Aa)n(Bb)n(Cc)n(Dd)n(Ee)n( . . . )n; wherein each capital letter and ( . . . ) is a metal described hereinabove; wherein each n is independently greater than or equal to zero; and wherein the alloy comprises at least two different metals. Thus, the sum of the n's is equal to or greater than 2. In an aspect, the ( . . . ) is understood to include the presence of at least one metal other than those defined by A, B, C and D and the respective compositional stoichiometry.
The metal for use in the alloy can also be selected from the group consisting of Al, Sb, Mg, Fe, Mo, Zn, Sn, B, Bi, Ca, Li, Na, K, Ba, Mn, Si, Cu, Cd, Co, Ni, Cr, Ti, Ce, and V. In an aspect, in the generic formula, each capital letter can be the same or a different metal.
Sources of the metal can include, but are not limited to, their aqueous salts, carbonyls, oxides, organometallics, and zerovalent metal powders. The aqueous salts can comprise, for example, hydroxides, nitrates, acetates, acetonates, ammonium salts, halides, phosphates, phosphonates, phosphites, sulfates, sulfonates, carboxylates, and carbonates.
The subscript letters of the disclosed generic formula represent compositional stoichiometries. For example, for an AaBbCc alloy, such as Fe0.68Al0.25Ce0.07 disclosed herein, a=0.68, b=0.25 and c=0.07.
In an aspect, the alloy can be a nanoalloy and can be bimetallic (i.e., any combination of two different metals from the same or different functional groups, e.g., AaBb, or AaA′a′); trimetallic (i.e., any combination of three different metals from the same or different functional groups, e.g., AaBbCc, or AaA′a′A″a″ or AaA′a′Bb); or polymetallic (i.e., any combination of two or more metals from the same or different functional groups, e.g., AaBbCcDdEe . . . etc. or AaBbB′b′CcDdD′d′Ee). The alloy must comprise at least two different metals, but beyond two the number of metals in each alloy would be dictated by the requirements of each specific combustion system.
In an aspect, the composition can comprise an alloy selected from the group consisting of a bimetallic, trimetallic, and polymetallic.
In an aspect, the disclosed alloy and particle can be a nanoalloy and a nanoparticle. The nanoalloy and nanoparticle can have an average size of from about 1 to about 100 nanometers, for example, from about 5 to about 75 nanometers, and as a further example from about 10 to about 35 nanometers.
One of ordinary skill in the art would know how to make the disclosed alloys. In particular, the disclosure of U.S. patent application Ser. No. 11/620,773, filed Jan. 8, 2007, the disclosure of which is hereby incorporated by reference.
Manipulation of reaction conditions will determine rate of reaction which will also determine the physical composition of the nanoalloy. For example, fast reaction rates will lead to low density and porous nanoalloys, and slow reaction rates to a denser and less porous product. This reduced surface area will adversely affect gas phase combustion, combustion emissions removal (i.e., SO3 and NOx from flue gases of utility boilers and incinerator furnaces), and deposit modification (slag in furnaces). Such higher density nanoalloys will find enhanced utility in ceramics. Porous nanoalloys will find enhanced utility in atmosphere combustion systems, while denser nanoalloys will be better suited for pressurized combustion systems. Such porous nanoalloys are described in Optical Materials, Tsui, Y. Y.; Sun, Y. W., Vol. 29, Issue 8, pp. 1111-1114 (April 2007).
It is believed that the disclosed alloys can enable active metal species to function cooperatively due to their intimate location together in functional units, such as nano units. The surface and the porosity of the alloy can be modulated by using nanotechnology methods of preparation known to those of ordinary skill in the art.
Also, disclosed herein is a fuel composition comprising a fuel and the disclosed additive composition. The fuel can be a solid, liquid, or gas. By “solid fuel” herein is meant, for example and without limitation herein, materials useful as explosives, propellants, munitions, and the like which can be produced in or changed to a solid form. Some examples of these include, but are not limited, to nitrated cellulose, which can also be melted to a liquid form. Other mononitrated, dinitrated, trinitrated and polynitrated materials can be used singularly or in admixture as fuels herein. Nitrated aromatic materials and nitrated polyaromatics are also useful herein. Other materials capable of explosion or detonation and which can in some manner or under some condition be provided in solid form are also useful herein. These might include, for example, epoxides, or epoxidized organic compounds, hydrides, metal hydrides, hydrazine and alkylated hydrazines, black powder propellant, zinc-sulfur, potassium nitrate, nitro glycerin, ammonium perchlorate, gun powder, and the like, and mixtures thereof, and other explosives or propellants known to those skilled in the art.
Moreover, the fuel can be a hydrocarbonaceous fuel such as, but not limited to, diesel fuel, jet fuel, alcohols, ethers, kerosene, low sulfur fuels, synthetic fuels, such as Fischer-Tropsch fuels, liquid petroleum gas, bunker oils, gas to liquid (GTL) fuels, coal to liquid (CTL) fuels, biomass to liquid (BTL) fuels, high asphaltene fuels, petcoke, fuels derived from coal (natural and cleaned), genetically engineered biofuels and crops and extracts therefrom, natural gas, propane, butane, unleaded motor and aviation gasolines, and so-called reformulated gasolines which typically contain both hydrocarbons of the gasoline boiling range and fuel-soluble oxygenated blending agents, such as alcohols, ethers and other suitable oxygen-containing organic compounds. Oxygenates suitable for use in the fuels of the present disclosure include methanol, ethanol, isopropanol, t-butanol, mixed alcohols, methyl tertiary butyl ether, tertiary amyl methyl ether, ethyl tertiary butyl ether and mixed ethers. Oxygenates, when used, will normally be present in the reformulated gasoline fuel in an amount below about 25% by volume, and for example in an amount that provides an oxygen content in the overall fuel in the range of about 0.5 to about 5 percent by weight. “Hydrocarbonaceous fuel” or “fuel” herein shall also mean waste or used engine or motor oils which may or may not contain molybdenum, gasoline, bunker fuel, coal (dust or slurry), crude oil, refinery “bottoms” and by-products, crude oil extracts, hazardous wastes, yard trimmings and waste, wood chips and saw dust, agricultural waste, fodder, silage, plastics and other organic waste and/or by-products, and mixtures thereof and emulsions, suspensions, and dispersions thereof in water, alcohol, or other carrier fluids. By “diesel fuel” herein is meant one or more fuels selected from the group consisting of diesel fuel, biodiesel, biodiesel-derived fuel, synthetic diesel and mixtures thereof. In an aspect, the hydrocarbonaceous fuel is substantially sulfur-free, by which is meant a sulfur content not to exceed on average about 30 ppm of the fuel.
In an aspect, the additive composition can be cold blended with the fuel, such as a solid fuel, at a treat rate of greater than 3 parts nanoparticles or nanoalloy per million parts (ppm) of solid fuel. In another embodiment, the treat rate can vary from about 5 ppm to about 25,000 ppm, for example from about 5ppm to about 500 ppm, and as a further example from about 100 ppm to about 500 ppm of solid fuel.
The alloys and particles disclosed herein can be formulated into additive compositions that can be in any form, including but not limited to, gels, colloids, aerogels, paste, semi-solid, crystalline (powder), or liquids (aqueous solutions, hydrocarbon solutions, sols, or emulsions). The liquids can possess the property of being transformable into water/hydrocarbon emulsions using suitable solvents and emulsifier/surfactant combination. The liquids can also be converted into high porosity high surface area powders.
The present disclosure, in another embodiment, is directed to combustion systems generally. Combustion systems can have multiple sections including, in very general terms, a furnace, a combustion or ignition section, and an emissions after-treatment system. Combustion systems that require solid fuels include certain coal burning power utility furnaces, flares, fireworks, munitions, and the like. Combustion systems that burn gaseous, liquid, solid fuels, and renewable fuels, and mixture thereof include, but are not limited to, three-way catalysts (TWCs), such as for stoichiometric charge feed combustion systems, lean-NOx traps (LNTs), lean-NOx catalysts (LNCs), selective catalytic reduction catalysts (SCRs), such as for lean-burn variable pressure engines (i.e., diesel engines, lean-burn spark ignited engines, etc.), oxidation catalysts (OCs), diesel oxidation catalysts (DOCs), industrial burners in boilers, incinerators, furnaces, and lean-burn atmospheric burners (i.e., utility furnaces, industrial furnaces, boilers, and incinerators). As used herein, the term “after-treatment system” is used to mean any system, device, method, or combination thereof that acts on the exhaust stream or emissions resulting from the combustion of gaseous, liquid, and solid fuels, renewable fuels, and mixtures thereof.
The disclosed additive composition can also be used in other systems, such as those of atmospheric combustion used in utility and industrial burners, boilers, furnaces, and incinerators. These systems can burn from natural gas to liquid fuels (#5 fuel oil and heavier), to solid fuels (coals, wood chips, burnable solid wastes, etc).
It is to be understood that the reactants and components referred to by chemical name anywhere in the specification or claims hereof, whether referred to in the singular or plural, are identified as they exist prior to coming into contact with another substance referred to by chemical name or chemical type (e.g., base fuel, solvent, etc.). It matters not what chemical changes, transformations and/or reactions, if any, take place in the resulting mixture or solution or reaction medium as such changes, transformations and/or reactions are the natural result of bringing the specified reactants and/or components together under the conditions called for pursuant to this disclosure. Thus, the reactants and components are identified as ingredients to be brought together either in performing a desired chemical reaction (such as formation of the organometallic compound) or in forming a desired composition (such as a washcoat composition). Accordingly, even though the claims hereinafter may refer to substances, components and/or ingredients in the present tense (“comprises”, “is”, etc.), the reference is to the substance, components or ingredient as it existed at the time just before it was first blended or mixed with one or more other substances, components and/or ingredients in accordance with the present disclosure. The fact that the substance, components or ingredient may have lost its original identity through a chemical reaction or transformation during the course of such blending or mixing operations or immediately thereafter is thus wholly immaterial for an accurate understanding and appreciation of this disclosure and the claims thereof.
The following examples further illustrate aspects of the present disclosure but do not limit the present disclosure.
The following procedure was used to produce cerium oxide nanoparticles having a particle size of less than 5 nanometers. Cerium acetate (1 gram, 0.00315 mols) was mixed with 7.5 mL of oleylamine (0.2279 mols) and 4.33 mL of oleic acid (0.13 mols) in a suitable vessel. The mixture was heated to 110° C. and held at that temperature for 10 minutes to provide a clear solution of cerium acetate without crystalline water in the solution. Next, the cerium acetate solution was irradiated with microwave irradiation for 10 to 15 minutes to produce a stable dispersion of cerium oxide in the amine and acid. The stabilized dispersion was washed 2-3 times with ethanol to remove any free amine or acid remaining in the dispersion. Finally, the stabilized cerium oxide product was dried overnight under a vacuum to provide the particles have a size of less than 5 nanometers. X-ray diffraction confirmed that nanoparticles of crystalline cerium oxide were produced. UV absorption of the product showed a peak at 300 nanometers which from extrapolation of the absorption edge indicated a band gap of 3.6 eV confirming that the nanoparticles have a diameter of less than 5 nanometers.
The following procedure was used to produce an alloy of magnesium and manganese oxide nanoparticles. Oleylamine (4.25 mL, 0.129 mols) and 1.36 mL of oleic acid (0.04 mols) was mixed in a suitable vessel that was stirred and heated in a hot oil bath to 120° C. and held at that temperature for 10 minutes. A mixture of magnesium acetate (0.14 grams) and manganese acetyl acetonate (0.34 grams) powder was added under vigorous stirring to the amine and acid to provide a clear solution. The solution was then microwaved for 15 minutes. After microwaving the solution, synthesized nanoparticles of magnesium/manganese oxide were flocculated with ethanol, centrifuged, and redispersed in toluene. The Mg0.3Mn0.7O nanoparticles made by the foregoing process have an x-ray diffraction pattern that indicates that traces of manganese oxide are included in the Mg0.3Mn0.7O alloy. The nanoparticles have cube-like structures similar to manganese oxide particles.
Preparation of a metallic or metallic/metalloid nanoparticle or nanoalloy additive core, can be carried out using any of the published prep methods that are deemed suitable. Particle size control can be achieved by selection of suitable blends of a fatty amine or carboxylic acid. Then the core nanoparticle or nanoalloy can be coated with a flame retardant ligand —R(X)m to give a neat FMA.
Na3PO4.12H2O+-nR(X)m→Na3PO4.12H2O[—R(X)m]n
Where R(X)m is a diaryl alkyl- or aryl-phosphonate of the type,
With R1 an alkyl group of carbon length 1-32, and n>1
Mn(NO3)2+Na2H2Sb2O7.7H2O→MnSb2O6
MnSb2O6+-nR(X)m→MnSb2O6.[—R(X)m]n, where;
R(X)m is a diaryl alkyl- or aryl-phosphonate of the type:
With R1 an alkyl group of carbon length 1-32, m=Br=5, and n>1
MnVSbO6+-nR(X)m→MnVSbO6.[-nR(X)m]n, where;
Where R(X)m is alkyl- and/or aryl-amines of the type:
And PIB is a low molecular weight polyisobutylene group
NaSbO3+Fe(NO3)3+Mn(NO3)2→FeMnSbO4
FeMnSbO4+-nR(X)m→FeMnSbO4[—R(X)m]n, where,
R(X)m is a polyhalogenated alky- and/or ary-halide such as:
And R1 is an alkyl group of carbon length from 1-32 carbon atoms.
Al(OH)3+(NH4)4Mo8O26→Al(OH)3.[(NH4)4Mo8O26]
Al(OH)3.[(NH4)4Mo8O26]+-nR(X)m→Al(OH)3.[(NH4)4Mo8O26].[—R(X)m]n, where,
R(X)m is an alkly- or aryl-phosphorus-derived oxide of the type:
And R1 is an alkyl group of carbon length from 1-32 carbon atoms.
In general, propellant fuels are of three major classes:
Cryogenics, i.e. hydrogen (H2), hydrazine (N2H4), ammonia (NH3), etc.;
Storables, i.e. Acetylene (C2H2), aluminum borohydride (AlBH4), ammonia (NH3), aniline (C6H7N), Biborane (B2H4), Ethanol (C2H6O), furfuryl alcohol, kerosene, pentaborane, unsymmetrical dimethyl hydrazine ((CH3)2NNH2 or UDMH), ethylene oxide, hydrogen peroxide, nitromethane, propyl nitrate, and etc. The latter four are known as “monopropellents” because they carry some of the oxidizer necessary for combustion; and
Solids, i.e. NH4ClO4-Polyurethane, NH4ClO4-Organo-boron, ammonium nitrate, epoxy plastics, nitrocellulose plastics, polyester plastics, nitroglycerin,
Cryogenics can enter the combustion zone as gases; therefore the appropriate flame modulation additive would have to be injected separately.
Storables are either liquids or solids that do not require extraordinary measures during handling, storage and use. When liquids, the combustion modulation additive would be dispersed in the fuel by selecting the appropriate length R-group on —R(X)m ligand coating the nanoparticle/nanoalloy additive core.
When the fuel is a solid or gel, then the additive needs to be mixed in during the fuel synthesis process at stages where the steps go through a liquid phase, and no further reactive steps follow that may alter the intended performance of the additive.
In one embodiment, a fuel additive comprising a nanoparticle matrix comprising oxides, and/or hydroxides, and/or hydrates of one or more of the following elements Al, Sb, Mg, Fe, Mo, Zn, Sn, B, Bi, Ca, Na, K, Ba, Bi, Si, Cu, Cd, Co, Ni, Cr, Ti, Ce, and V is blended at a treat of 500 ppm of fuel additive nanoparticle matrix with non-nitrated cellulose pre-fuel at ambient temperatures. The resulting additized pre-fuel mixture is then nitrated using known reaction parameters and conditions resulting in a solid fuel containing a nanoparticles matrix, wherein the combustion rate of the cellulose fuel has been modulated relative to the combustion rate of nitrated cellulose.
In another embodiment, a fuel additive comprising a nanoparticle matrix comprising oxides, and/or hydroxides, and/or hydrates of one or more of combinations selected from the group consisting of Na/B, Zn/B, Na/Sb, and Fe/Mn is blended at a treat rate of 100 ppm of fuel additive nanoparticle matrix with non-nitrated cellulose pre-fuel at ambient temperatures. The resulting additized pre-fuel mixture is then nitrated using known reaction parameters and conditions resulting in a solid fuel containing a nanoparticles matrix, wherein the combustion rate has been modulated relative to the combustion rate of nitrated cellulose.
The solid test fuel is characterized in the pertinent combustion environment and the oxidation reaction rates determined. This provides the key baseline parameter for ranking the combustion modulation effect of the additive formulations.
Additives i)-ii) are formulated into the solid fuel. First additives i) and then additives ii) will be formulated into chosen solid fuel at 100 ppm wt/wt total metal.
Combustion rates of the fuels will be carried out and selection of additives for specific desired applications made.
Best additives from i) and ii) will be modified as shown in iv) through x), respectively and formulated into the respective solid fuel. Reaction rates are then determined as above.
At numerous places throughout this specification, reference has been made to a number of U.S. patents, published foreign patent applications and published technical papers. All such cited documents are expressly incorporated in full into this disclosure as if fully set forth herein.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural referents unless expressly and unequivocally limited to one referent. Thus, for example, reference to “an antioxidant” includes two or more different antioxidants. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.
This invention is susceptible to considerable variation in its practice. Therefore the foregoing description is not intended to limit, and should not be construed as limiting, the invention to the particular exemplifications presented hereinabove. Rather, what is intended to be covered is as set forth in the ensuing claims and the equivalents thereof permitted as a matter of law.
Applicant does not intend to dedicate any disclosed embodiments to the public, and to the extent any disclosed modifications or alterations may not literally fall within the scope of the claims, they are considered to be part of the invention under the doctrine of equivalents.
