Nitrated non-cyclic N-Alkane scaffolds with differentiated-mean combustive equivalencies as high energy density fuel improvers

Abstract

A non-ring, non-alkene, nitrated n-alkane base scaffold combined with at least one trioxynitrate provides a differentiated-mean combustive performance in a stabilized and sufficiently polar molecule as to be miscible, and thus serve as a high-energy-density component of a fuel additive that, when mixed with existing fuels at appropriate dilution ratios, will impart equivalent combustive efficiency to that of standardized, petroleum distillate, gasoline and diesel in various blends including aviation fuel and heating oil over the full-temperature-range of use; and a specific embodiment of this non-ring, non-alkene nitrated n-alkane base scaffold is described which, when blended with a petroleum diesel, biodiesel, or combination of B-20 standard biodiesel (80% diesel, 20% biodiesel) wherein the additive comprises less than 5% of the total mix, produces at least a 10% or greater combustive energy density as compared to the base fuel.

Description

BACKGROUND OF THE INVENTION

Fuel production for internal combustion engines has focused on providing fuels with narrowly-differentiated mean combustive efficiencies; and more particularly on producing mixtures that use extremely uniform combustive processes (boiling point) to produce the combustive energy. Each of aviation, gasoline, diesel, biodiesel, marine, and heating fuels are fractionated into equivalency groups with the combustive mean generally aiming for a given ‘octane number’ or ‘cetane number’ for all parts of the combustive activity.

On-road and off-road consumption of diesel fuel in the U.S. are each about 40 billion gallons a year. Diesel fuel refineries have been operating at over ninety percent capacity for the last ten years. The American Trucking Association states that there are over 10 million large trucks and buses registered in the US, mostly with diesel engines, operated by 750,000 companies. Worldwide diesel fuel demand has been increasing at a faster rate than gasoline fuel over the past 5 years, and diesel fuel prices are likely to remain at a premium to gasoline fuel prices as world demand for petroleum-based distillate fuels remains high.

The diesel engine was one of the first ‘internal combustion’ engines (as opposed to the external combustion of a steam engine) and was developed at the end of the nineteenth century, when mechanical rather than electrical control was both the norm and the limiting factor on engine designs. The ‘diesel cycle’ was named after Dr. Rudolph Diesel, who in 1898, was granted U.S. Pat. No. 608,845 for an “internal combustion engine”. Diesel engines use compression to ignite their fuel, unlike the gasoline engine's Otto cycle which uses an electrical spark. Diesel engines have the highest thermal efficiency of any internal or external combustion engine, because of their compression ratio.

Diesel engines have a number of design considerations that are not as great a concern for gasoline engines. These include requiring higher quality metallurgy for a given combustion cylinder volume, due to diesel engines' higher compression values and use of fuel-air injection technologies; experiencing more trouble with cool and cold weather operation, particularly starting; and experiencing problems with diesel fuels at only moderately cold or even just cool temperatures (depending upon the fuel's cloud point).

Diesel fuel is prone to “waxing” or “gelling”—terms for the solidification of diesel oil into a partially crystalline state—in cold weather. Crystals build up in the fuel line (especially in fuel filters), eventually starving the engine of fuel and causing it to stop running. Due to improvements in fuel technology, particularly the use of special additives, waxing rarely occurs in modern diesel engines even in all but the coldest weather—when a mix of diesel and kerosene is generally recommended.

Today's diesel engines and fuels, made respectively by engine manufacturers and petroleum refining companies, are principally designed to maximize economy in their production and reduce exhaust emissions, the better to meet these large entities' economic interests and the world's more stringent environmental standards. Virtually all of these fuels are created by the refiner fixing, for each fuel to be refined and created, a single fractionation yield as the primary determinant for a given mix of crude oil (petroleum) inputs, “by isolating mixtures of molecules according to the mixture's boiling point range” (see http://www.petrostrategies.org/Learning_Center/Refining.htm). These fractions are created by the refiner simplifying the reality of continuous differentiation during processing according to a model through picking a ‘standard’ combustive volatility as the goal, and using the “stream TBP (True Boiling Point) cut point scheme” in a massive linear-programming production matrix. Blending options are considered to be ‘secondary’. See http://www.cheresources.com/refinery_planning_optimization.shtml. Product specifications for most fuels' combustive effect—the main purpose and function of the fuel—focus on a single mean value, the “heat of combustion”, which is expressed as the BTU/unit volume; for example, gasoline averages 125,000 BTU/U.S. gallon, methanol averages 64,600 BTU/gallon, diesel averages 138,700 BTU/U.S. gallon, and biodiesel averages 126,200 BTU/U.S. gallon. See http://en.wikipedia.org/wiki/Fuel_efficiency#Energy_content_of_fuel.

As a consequence of this (re)design for the refiners' economic efficiency, currently users of diesel engines encounter operating problems that were a lesser concern for those making these refinery design and operational changes. Today, diesel engines are characterized by these features and consequences:

High Compression:        Hard Starting;
Low Sulfur Fuels:        Reduced Lubricity and
                         More Rapidly Eroded Fuel Injectors; and
Greater Soot Production: More extensive Exhaust control, greater engine
                         wear, and more lubricating oil contamination.

While today's diesel fuels are characterized by these problems and consequences:

Inconsistent, varying      Power reduced and storage compromised by
Cetane Number:             auto-oxidation of the fuel during storage;
Wax, Particulate, Fungal & Inconsistent performance & greater wear;
Water Contaminants:
Freezing at Winter         Clogging lines and fouling tanks.
Temperatures:

In spite of a sizable production of diesel additives, the users of diesel engines continue to bear the brunt of these shortcomings of the designs favored by diesel engine and petroleum fuel manufacturers, because there is no single additive or combination of additives that is a comprehensive solution to the problems of the users of diesel engines.

Additionally, alternative production choices—whether from natural gas liquefaction, or coal-to-liquid-fuel “synthetic gas” production (e.g. through the Fischer-Tropsch Synthesis approach, see http://en.wikipedia.org/wiki/Fischer-Tropsch_process) are also bound to the drive towards creating a single mean combustive value by selecting molecular compositions with that value created through their common exothermic reactive result.

FIELD OF THE INVENTION

The present invention relates generally to the production of a fuel additive which combines in one molecule differentiated exothermic combustive reactions that, when averaged together with lower heat of combustion fuels, let the mix match the desired combustive effects of existing petroleum-based standard fuels; wherein that molecule is a nitrated, non-ring, n-alkane scaffold combining the lower BTU/unit heat of combustion of the n-alkane with a very much higher BTU/unit heat of combustion of the nitrate.

DESCRIPTION OF THE RELATED ART

U.S. Pat. No. 6,102,975, issued on Aug. 15, 2000 to Marr, W. (hereinafter ‘Marr’), describes in its specification the prior art for that patent and the field generally. That portion of that patent, “Description of the Prior Art”, is hereby incorporated specifically by reference. It should be noted that all of the prior art cited in that patent was for fuel additives whose purposes were entirely secondary to affecting the mean heat of combustion of the fuels to which they were added. Marr also does not attempt to directly affect the mean combustive efficiency of the fuel; instead his invention's function is described thusly: “The compositions of the instant invention contain effective detergent and dispersant chemicals which reduce the formation of fuel injector deposits, and help to maintain maximum combustion efficiency.” (Col. 3, lines 8-11.) Walters, U.S. Pat. No. 2,410,846, cited by Marr, was focused on oxidative stability and presumed use of the now-environmentally-unacceptable gasoline compositions using tetra-alkyl lead (Col. 1, lines 1-19); while Denison et al., U.S. Pat. No. 2,676,094, also cited by Marr, focused on improving the anti-knocking (pre-ignition combustive stability) aspect of high-octane aviation gasolines (Col. 5, lines 51-58).

Similarly, Krutzch et al., U.S. Pat. No. 5,522,905, focused on pollution particulate reduction through improving the combustion of soot. (Col. 1, lines 11-12.)

It is known that diesel fuels with a higher cetane rating modify the combustion process and reduce diesel clatter. Cetane rating is generally measured by use of the “Cetane number” or CN; and the CN is a measurement of the combustion quality of diesel fuel during compression ignition. It is a significant expression of diesel fuel quality among a number of other measurements that determine overall diesel fuel quality. The CN for a diesel fuel can be raised by distilling higher quality crude oil, or by using a cetane-improving additive. Some oil companies market high cetane or premium diesel; see British Petroleum's “BP ultimate” referenced at: http://www.bp.com/sectiongenericarticle.do?categoryId=4005623&contentId=7009145.

Biodiesel has a higher Cetane number than petrodiesel, typically 55CN for 100% biodiesel (see http://en.wikipedia.org/wiki/Diesel_engine). Biodiesel dates back to 1900, when at the request of the French Government the Otto company demonstrated a diesel engine at the 1900 Exposition Universelle (World's Fair) which used peanut oil, as the French government was then exploring the possibility of using a locally produced fuel in their African colonies. Diesel himself later tested extensively the use of plant oils in his engine and began to actively promote the use of these fuels. One of the chief problems of biodiesel fuels has been their inherently high cloud point, relative to petroleum-derived diesel fuels. Biodiesel's utility has been seen as limited, as the fuels’ cloud points were so high as to limit their use to the tropics or other hot climates or locations.

The principle limits on the fuels used in diesel engines are the ability of the fuel to flow along the fuel lines, and the ability of the fuel to lubricate the injector pump and injectors adequately. In general terms, inline mechanical injector pumps tolerate poor-quality or bio-fuels better than distributor-type pumps. Also, generally indirect injection engines run more satisfactorily on bio-fuels than direct injection engines. This is partly because an indirect injection engine has a much greater ‘swirl’ effect, improving vaporization and combustion of fuel, and also because (in the case of vegetable oil-type fuels) lipid depositions can condense on the cylinder walls of a direct-injection engine if combustion temperatures are too low (such as when starting a cold engine).

The existing state of the art considers that diesel engines run well with a CN ranging from 40 to 55. Fuels with higher Cetane numbers have shorter ignition delays, and thus provide more time for the fuel combustion process to be completed. Hence, higher speed diesels operate more effectively with higher Cetane number fuels—up to a point, in the prior art. There has been and is currently no performance or emission advantage perceived when the CN is raised past approximately 55; after this point, the fuel's performance was presumed to hit a plateau. In North America, diesel at the pump can be found in two CN ranges: 38-42 for regular diesel, and 42-45 for premium. Premium diesel may have additives to improve CN and lubricity, detergents to clean the fuel injectors and minimize carbon deposits, water dispersants, and other additives depending on geographical and seasonal needs. Dimethyl ether is one additive that both has a high cetane rating (55) and can be produced as a biofuel; alkyl nitrates (principally 2-ethyl hexyl nitrate) and di-tert-butyl peroxide are alternative additives used to raise the Cetane number; biodiesel from vegetable oil sources have been recorded as having a Cetane number range of 46 to 52; and animal-fat based biodiesels' Cetane numbers range from 56 to 60. See http://en.wikipedia.org/wiki/Cetane_number.

Cetane (formally Hexadecane), has the chemical formula C16H34 and is one of the alkanes (the others being Methane (CH4), Ethane (C2H6), Propane (C3H8), Butane (C4H10), Pentane (C5H12), Hexane (C6H14), Heptane (C7H16), Octane (C8H18) Nonane (C9H20), Decane (C10H22), Undecane (C11H24), and Dodecane (C12H26)). Hexadecane, as the formal name indicates, consists of a chain of 16 carbon atoms with three hydrogen atoms bonded to the two end carbon atoms, and two hydrogens bonded to each of the 14 other carbon atoms. It has 10,359 constitutional isomers. Cetane, because it is an un-branched, open-chain alkane molecule, ignites very easily under compression, so it was assigned a Cetane number of 100, while alpha-methyl napthalene was assigned a cetane number of 0. All other hydrocarbons in diesel fuel are indexed to cetane as to how well they ignite under compression. The CN therefore measures how quickly a fuel starts to burn (auto-ignites) under diesel engine conditions. Since there are hundreds of components in diesel fuel, with each having a different cetane quality, the overall Cetane number of the diesel is the average cetane quality of all the components. There is very little actual cetane in diesel fuel.

BP's “Ultimate Diesel” is advertised as having, “a cetane number of 55 minimum, significantly higher than the standard 51 cetane for diesel fuels in this market. This improved cetane quality means that BP Ultimate Diesel burns more smoothly and completely than ordinary diesel, so it can help deliver improved performance and better fuel economy, and reduce exhaust emissions and engine noise.” (BP Web Cite supra.)

There have been considerable efforts to find fuel additives for gasoline engines and other efforts to find fuel additives for diesel engines. Known additives include:

• • Ether and other flammable hydrocarbons, which have been used extensively as starting fluid for many difficult-to-start engines, especially diesel engines;
  • Nitrous oxide, which is an oxidizer used in auto racing;
  • Nitromethane, or “nitro,” which is a high-performance racing fuel;
  • Acetone, which is a vaporization additive mainly used with methanol racing fuel to improve vaporization at start up;
  • Butyl rubber (as polyisobutylene succinimide) which is a detergent to prevent fouling of diesel fuel injectors;
  • Ferox, which is a catalyst additive that increases fuel economy, cleans engines, lowers emission of pollutants, and prolongs engine life;
  • Oxyhydrogen, which is used to inject hydrogen and oxygen into engines as a supplemental fuel to improve fuel efficiency;
  • Ferrous picrate, which improves combustion and increases fuel mileage;
  • Silicone, which is an anti-foaming agent for diesel, but may damage oxygen sensors in gasoline engines; and,
  • Tetranitromethane, which can increase the cetane number of diesel fuel, thereby improving its combustion properties.

Because of the different operating principles, additives that function well for gasoline may or may not perform with the same qualitative advantage(s) with diesel (either fuels or engines). Also, because of the gelling problem identified above, diesel fuels generally come and are used in two broad classes, Diesel 1 for warmer operating conditions and Diesel 2 for colder operating conditions.

An alternative approach to increasing the cetane number for diesel fuels was disclosed a quarter-century ago in Hinkamp, U.S. Pat. No. 4,417,903, wherein a “diesel fuel selected from the group consisting of liquid hydrocarbons of the diesel boiling range, alcohols and mixtures thereof” was combined with “a cetane increasing amount of a primary nitrate ester having the structure

wherein R′ is an alkyl group containing 1-20 carbon atoms, R″ is selected from the group consisting of hydrogen and alkyl groups containing 1-20 carbon atoms and n is an integer from 1 to 4.” (Col. 1, line 56-Col. 2, line 2.) All of the “nitro-substituted primary n esters” in Hinkamp are NO₂-based or dioxynitrates (Col. 2, lines 3-27). Hinkamp, however, limited the range of the dioxynitrate (NO₂) additive to 0.5-25% by weight (Col. 2, lines 63-68); and even more specifically limited the range for petroleum-derived diesel fuels to 0.01-5% weight (Col. 3, lines 16-17). Within two months a second patent issued to Thomas, U.S. Pat. No. 4,420,311, issued which taught the use of cyclododecyl nitrate to increase the cetane number for diesel fuels like those referenced in Hinkamp. (Col. 1, line 35 to Col. 2, line 4.) Thomas also focused on a dioxynitrate (NO₂) based additive, and cited the same range by weight (Col. 2, lines 37-42; 58-62) found in Hinkamp. Both of these patents were assigned to the Ethyl Corporation; though Thomas failed to mention Hinkamp's prior work.

More recently, the concept of using alkanes for a diesel fuel cetane number increaser was taught in Waller et al., U.S. Pat. No. 5,858,030. That patent combined a dialkoxy alkane (DAAK) with “moderate amounts of dimethoxy propane (DMPP) and dimethoxy ethane (DMET) blended into a conventional diesel fuel.” (Col. 2, lines 32-34.) This patent specifically mentions the unexpected synergism as the cetane number increase of the combination in the additive is such that “this percentage increase is much greater than the sum of the parts increases that could be expected”. (Col. 3, lines 51-53.)

An unasked question in all of the above is whether there might be an alternative means to improving a fuel's most basic function—efficient combustion. Would it be possible to increase not just the “cetane number” but the energy density of a fuel, by creating a molecular scaffold with the right set of additive compounds such that the differentiated BTU/unit weight effectiveness of the exothermic reactions of the parts of the molecule, when that molecule is part of an additive, could equal or even improve upon the mean BTU/unit weight energy production of petroleum-distillate fractionations? Or even low-energy-density simple alcohols? If instead of aiming for as uniform a “heat of combustion” for a given combustive efficiency for a fuel, whether measured by Cetane Number or Octane Number, instead a differentiated-mean “heat of combustion” improver to upgrade the resulting fuel's energy-equivalent-density were sought?

OBJECTS OF THE PRESENT INVENTION

It is a principal object of the present invention to provide a multi-functional, high-energy-density fuel additive (hereinafter HEDFA) which by combining differentiated, yet stable combustive processes, can be added to existing lower-energy-density fuels in proportion to meet desired combustive efficiency.

It is an object of the present invention to provide a single fuel additive to diesel fuel that completes the diesel fuel purchased from various sources so that it is compatible with diesel engines whether in service on-road or off-road, whether used in automobile, rail and marine environments, or whether used in heating and power generation services for residential and commercial use.

It is further an object of the present invention to provide a fuel additive that when used with one part of additive to one thousand parts of diesel fuel, the Cetane Number of the new combination is increased by a minimum of four units (e.g. 40-44 or 42-46).

It is still further an object of the present invention to produce a fuel additive that when mixed with a diesel fuel as heating oil, will change the engine exhaust smoke from black to white and decrease the noise level of the engine.

It is another and further object of the present invention to produce a fuel additive that sufficiently enhances the cold weather characteristics of Diesel 1 fuel so that it performs equal to or better, at cold temperatures, than Diesel 2 fuel, so that the problems associated with seasonable change of fuels are eliminated.

It is still a further objective of the present invention to produce a fuel additive that will reduce the cloud point of biodiesel from palm, soy and other feedstock, to equal or exceed the cloud point of crude-oil-based diesel fuel.

It is still another object of the present invention to produce a fuel additive that will sufficiently retard the ignition and improve the spray pattern of the fuel in a diesel engine so that ignition for the cylinder occurs on the power stroke to improve the power derived from the fuel that translates into a minimum increase in miles per gallon, of ten percent, and a reduction in the exhaust pollutants, of twenty-one percent.

It is still another object of the present invention to produce a fuel additive that supplements the lubricity and detergent cleaning of diesel fuel so as to clean, protect and maintain the spray pattern of the fuel injector system and the mechanical component thereof, thus increasing engine life and reducing engine maintenance needs.

It is still a further object of the present invention to produce a fuel additive that treats the fuel storage and pumping system so as to eliminate condensate water in tanks that cause corrosion and required maintenance, retards chemical oxidation that deactivates the fuel during storage, and reduces gelling that clogs fuel line and fuel pumps, reducing the operating costs for the diesel engine.

It is still another object of the present invention to produce a fuel additive that will increase the intervals between oil drains, fuel injection systems component replacement, cleaning fuel storage and feed system and rebuilding engines.

It is still another object of the present invention to produce a fuel additive whose principal material contains an energy density between 20 and 50 times that of petroleum distillate diesel fuel.

It is still another object of the present invention to produce the high energy component principal material in the fuel additive when blended with methanol of ethanol at a concentration of 5% or less will produce an energy density equal to the energy density of petroleum distillate diesel of gasoline fuels.

SUMMARY OF THE INVENTION

The present invention employs a novel and non-obvious combination of elements to create a multi-functional, high-energy-density fuel additive (HEDFA) which provides such a higher energy density per unit of the additive that a single quart of the HEDFA when combined with two hundred and fifty gallons of a base fuel (e.g. diesel or heating) will increase the combustive efficiency of the desired blended fuel by at least 10%. This HEDFA is the “keystone” between diesel engines and diesel fuel, and delivers benefits of up to 15% more mileage, 21% less exhaust emissions, longer interval between oil drains and engine overhauls, improvements in fuel injection and engine ignition points, and decreased maintenance of fuel pumping and storage systems. While other additives only provide one “piece-of the-puzzle”, the present invention is the only additive a diesel engine owner will ever need to make any diesel premium.

By combining differentiated combustive efficiencies, the first being that of an stabilizing, non-cyclic and non-aromatic alkane scaffolding, and the second being that of an attached trioxynitrate (NO₃), and making this trioxynitrated n-alkane (xTONnA) the plurality (at least 40%) ingredient of the HEDFA, this invention creates a HEDFA so comprised having both a mean-value “heat of combustion” and a BTU/unit volume energy density sufficient to improve the combustive efficiency, and thereby the Cetane or Octane Number and performance of a fuel as desired, by mixing therewith in appropriate ratio. For example, by attaching NO₃ to a linear saturated, non-cyclic or non-ring hydrocarbon that can be polymerized from methane, ethane or propane gas, we start from an n-alkane scaffold which on its own comprises a fuel with a high flash point (165° F.) but with lower BTU/unit weight combustive efficiencies than standard diesel or gasoline; to this alkane scaffold fuel we then attach at least one and no more than three NO₃ groups. With a single NO₃ group attached a resulting multi-functional fuel additive is produced that has 1.7-2.0 million BTU per pound (vs Diesel at 17,500 BTU per pound), when the xTONnA is present at fifty percent by volume in the HEDFA. A second NO₃ will mean 2.0-4 million BTU per pound, and a third NO₃ will mean 4-6 million BTU per pound.

The present invention's fuel additive to diesel provides benefits to diesel engine performance of the following:

• • Maximum combustion efficiency;
  • 4 Numbers Plus Cetane number improver;
  • Ash reducer or even ashless;
  • Pour point decreased to 35-40° F. below zero;
  • Algaecide;
  • Increased fuel stability;
  • Superior corrosion protection;
  • Eliminate ring seizures;
  • Improved oxidation;
  • Improved crankcase cleanliness;
  • Exhaust emissions reductions of:
    • NOx;
    • Raw hydrocarbon of 10.2%; and
    • 38% soot reduction, Lucas CAV 6 hour test;
  • Alcohol free;
  • Flash point ASTM D93 of 85° F.;
  • Increased lubricity—Shell four-ball wear test 30% increase;
  • Decreased coefficient of friction—Shell four-ball wear test 45% decrease;
  • Anti-sludge performance—Sundstrand pump test rated: Good;
  • Increased miles per gallon by 8 to 15%; and,
  • Longer filter and pump life.

DESCRIPTION OF DRAWINGS

FIG. 1 is a drawing of the chemical bonds and structure of the xTONnA alkane, x-TriOxyNitro-n-Alkane, defined below as any non-cyclic and non-aromatic, non-alkene, linear or saturated hydrocarbon of the formula C_nH_2n+2 base scaffolding to which at least one trioxynitrate (NO₃) is attached.

FIG. 2 is a graph of the composition in the preferred embodiment as it was analyzed by a Gas Chromatograph Mass Spectrograph, using TIC: 9016002.D\data.ms, with time forming the horizontal and abundance the vertical axes respectively, showing the preferred embodiment's composition is a complex mixture of hydrocarbons with considerable overlap between a number of compounds.

DETAILED DESCRIPTION OF THE INVENTION

A multi-functional combustively dense, or high-energy-density fuel additive (HEDFA), which in the preferred embodiment is to be mixed with a ratio of one part of fuel additive to 1,000 parts of fuel, but which can be mixed in a range between one part of additive to 5,000 parts of base fuel, to one part of additive to 50 parts of base fuel to create a desired blended fuel, is comprised of one or more members of a molecular family having an n-alkane base scaffolding to which at least one trioxynitrate (NO₃) is attached (xTONnA, for x-TriOxyNitro-n-Alkane), which in the preferred embodiment is 2-Ethylhexyl nitrate, having the following basic structure:

and the molecular linear formula CH₃(CH₂)(C₂H₅)CH₂ONO₂, though the n-alkane itself can be any non-cyclic and non-aromatic, non-alkene, linear or saturated hydrocarbon of the formula C_nH_2n+2; with said molecules comprising at least the plurality of the additive. These formulations produce the unexpected result of creating a fuel additive that even at one part per thousand mixed with a fuel that has a lower energy density than premium diesel has the following 10 benefits: cleaning ejector ports; retarding pre-stroke combustion; boosting cetane number; enabling low-temperature operation; retarding auto-oxidation of stored fuel; removing water condensate; inhibiting corrosion; acting as an algaecide; reducing smoke/emissions; and providing an MPG increase; which occurs through the combination of the stable boiling feature of the n-alkane base scaffolding with an otherwise unstable and dangerous density of combustive energy from the 2-Ethylhexyl Nitrate or other trioxynitrate group. When mixed in proportions ten times greater than previously stated in the prior art in the additive mix, this high-energy-density fuel additive more than compensates for the relative energy-deficits of and allows fuels such as the simple alcohols (methanol, etc.), or biodiesel, to be used in engines, diesel or gasoline, because it completes the alcohol or the biodiesel to make a tremendously valuable synthetic fuel.

The n-alkane base scaffolding is chosen as it provides a lower end of combustive efficiency through the combustive effect of the carbon bond transformations. The attached trioxynitrate provides a tremendously higher combustive efficiency through the combustive effect of the nitrogen bond transformations. One of the unexpected aspects of the present invention is that deliberate use of only non-alkene, non-ring, non-aromatic alkanes, provides sufficient stabilization to the trioxynitrate so that the combined molecule's boiling point is near that of the n-alkane base scaffolding and the stabilization is sufficient to permit the use in an internal combustion engine, rather than producing a detonation as happens with ring compounds such as trinitrotoluene.

A second unexpected aspect of the present invention is that the difference between the ionic nature of the n-alkane base scaffolding's H₃C and NO₃ sub-attachments produces a molecule which is sufficient polar to be miscible in either simple (non-isomeric) alcohols such as methanol, ethanol, propanol, and butanol, or standard diesel hydrocarbons without precipitating in the diesel hydrocarbons, and thus becomes suitable for use as a fuel additive in combustion engines using these fuels.

A third unexpected aspect of the present invention is that the use of a much higher total proportion of the differentiated combustive efficiency, high-energy-density additive as part of the total additive package, provides a stable combustive efficiency that enables blending with a fuel to effect a correction of the combustive deficit of the result that makes the synthesized combination as effective or more effective than petroleum distillate premium diesels or even aviation gasolines.

If prepared for petroleum-distillate based fuel blending, the HEDFA will have a composition in the following range:

	Concentration
Component	Volume, %	CAS Number
2-Ethylhexyl Nitrate	40-60	27247-96-7
Petroleum Distillates	25-30	mixture
1,2,4-Trimethyl-benzene	3-7	95-20-3
Long Chain Alkyl Amide	3-7	e,g, Oronite ODA 78012
		(proprietary to Chevron)
m-Cresol	3-7	108-39-4
Xylenol	3-7	1300-71-6
p-Cresol	5-6	106-44-5
Vinyl Acetate	5-6	108-05-4
Ethyl Phenols	2-5	25429-37-2.

According to the invention, the stated objectives are achieved by means of adding, in the ratio of one part of the fuel additive to one thousand parts of diesel fuel with an average Cetane number of 38-55, a composition providing a combustive efficiency improvement, said composition in one embodiment of the present invention being:

if prepared for a Non p-Cresol (CAS 108-05-4) formulation:

	Component Name	% by Weight	CAS
	Ethylhexyl Nitrate	40-60	27247-96-7
	Solvent Naphtha, Petroleum,	5-15	64742-94-5
	Heavy Arom.
	Ethylene Glycol Monobutyl	5-15	111-76-2
	Ether
	Solvent Naphtha, Petroleum,	<5	64742-95-6
	Light Arom.
	1,2,4-Trimethylbenzene	<5	95-63-6
	Naphthalene	<2	91-20-3
	Xylene	<0.5	1330-20-7
	Ethylbenzene	<0.1	100-41-4;

and for an alternative, preferred embodiment formulation:

	Concentration
Component Name	Volume (%)	CAS Number
2-Ethylhexyl Nitrate	50	27247-96-7
Petroleum Distillates	18.4	mixture
1,2,4-Trimethyl-benzene	5	95-20-3
Long Chain Alkyl Amide	5	e,g, Oronite ODA 78012
		(proprietary to Chevron)
m-Cresol	5	108-39-4
Xylenol	5	1300-71-6
p-Cresol	4	106-44-5
Vinyl Acetate	4	108-05-4
Ethyl Phenols	3.6	25429-37-2.

In all of the above embodiments the 2-Ethylhexyl Nitrate (which provides 50% of the combustive efficiency and Cetane Number improver in the preferred embodiment) is of the form shown in FIG. 1 above, has the linear formula of CH₃(CH₂)3CH(C₂H₅)CH₂ONO₂, the molecular weight of 175.23, the CAS Number of 27247-96-7, the EC Number of 248-363-6, the MDL number of MFCD00011582 and is also identified as PubChem Substance ID: 24857676. This component costs ten times per unit weight as much as diesel fuel to produce, but provides over ten times that again (125) in BTU per unit weight the thermal energy in use.

An alternative formulation replaces the 2-Ethylhexyl Nitrate, and comprises:

Component                        Concentration Volume, %
2-methyl-2nitro-1-propanol nitrate 40-60;
Petroleum Distillates            25-30;
1,2,4-Trimethyl-benzene          3-7;
Long Chain Alkyl Amide           3-7;
m-Cresol                         3-7;
Xylenol                          3-7;
p-Cresol                         5-6;
Vinyl Acetate                    5-6;
                                 and,
Ethyl Phenols                    2-5.

A sample of the composition in the preferred embodiment is also described as it was analyzed by Gas Chromatograph Mass Spectrograph with the result shown in Figure Two. The composition is a complex mixture of hydrocarbons with considerable overlap between a number of compounds, as can be seen from the figure. There are many aromatic compounds found including xylenes, trimethyl benzenes, tetramethyl benzene, pentamethyl benzene along with various ethyl, propyl, and butyl substitutions as well. There were also a number of phenols including di- and trimethyl phenols with various substitution patterns, methyl ethyl phenol and propyl phenol. Several heptenes are also identified, with the double bond at the 1,2 and 3 positions and possibly cis- and trans-isomers. We also find 2-nitropropane, pentanal, 2-ethylhexanal, 2-ethylhexanol, 3-methylacetophenone, indane, methyl indane, and naphthalene. Many of the library search hits that were not very good are not reported. There was also found a peak for nitrous oxide; however, as this has a simple mass spectrum it could be mistaken. Additional work could possibly resolve some of the overlapping compositive results, but it would require reconfiguring the mass spectrometer.

It is possible, due to the increased energy density provided by the trioxygenated nitro group portion of the xTONnA, to use lower-energy-density n-alkanes, including the simple alcohols, yet produce a HEDFA which not only makes up for the n-alkane portion but also the energy deficit of the base fuel to which the HEDFA is added to create a final desired blended fuel with energy densities equal to or greater than premium diesel. For example, it is possible to use as the base scaffolding n-alkane any combination of n-alkane-based, water-soluble simple alcohols having no more than two isomers, that is, any combination of methanol, ethanol, proponol, and butanol (including pure methanol, pure ethanol, pure proponol, pure butanol, or any combinatory mix thereof) and, by incorporating the trioxynitrate group(s) and altering the proportion of the xTONnA to the other elements of the additive, increase the combustive energy of the final blended fuel.

This is particularly attractive as the HEDFA can be manufactured from gases of geological or biomass origin (natural gas, bio-methane, plant alcohols, etc.) and not from crude oil or petroleum distillates. Such a mixture can even meet current standards and limitations on biodiesel, when the HEDFA is manufactured wherein the xTONnA is methanol; and the desired blend can further comprise up to 20% by volume biodiesel, <5% by volume HEDFA, and the remainder diesel.

Alternatively, and more attractively, the approach should use an ‘energy equivalence’ replacement process, such that the blend of additive, diesel, and biodiesel is such that up to 50% of the BTU/unit volume is provide by the HEDFA; and the balance of the BTU/unit volume is provided by the diesel or biodiesel.

Method for Determining Volume of High-Energy-Density Additive Required

One liter of ethanol, methanol and gasoline contains 21.1 MJ, 15.8 MJ and 32.6 MJ, respectively. Therefore on a volumetric basis, 1.6 liters of ethanol and 2.1 liters of methanol are needed to supply the same combustive energy as 1 liter of gasoline. The relative energy efficiency of ethanol is thus (1.0/1.6=0.625), or 62.5% of gasoline.

If prepared for use as an trioxynitrated n-alkane-based fuel additive as in the present invention's preferred embodiment, methanol, which has a BTU/unit ration of 47,742, and the trioxynitrated n-alkane-based fuel additive are mixed in the appropriate ratio to a desired (high) combustive efficiency and CN for diesel fuel. This works out to 0.86 ounces of the trioxynitrated n-alkane-based fuel additive to 127.14 ounces of methanol, assuming a 50% proportion of 2-ethyhexyl nitrate in the additive. The calculation method used is as follows:

Diesel's combustive efficiency is rated at 138,700 BTUs per gallon, while methanol rates at the much lower value of 47,742 BTUs per gallon. If the Goal Energy Density (GED) is that of a diesel, then methanol's Combustive Energy Deficit (CED) is 90,958 BTUs per gallon (138,700−47,742). The preferred embodiment's HEDFA has an energy density of 13,477,777 BTU/oz. Thus, methanol's CED can be made up by using 0.86 ounces of the preferred embodiment trioxynitrated n-alkane-based fuel additive; (90,958 BTUs/(13,477,777 BTUs/128 ounces per gallon)). For other alkanes, a like ‘BTU make up’ calculation gives the mixing ratio.

The method for producing the desired fuel energy density for any fuel per unit volume is:

State the Goal Energy Density (GED) per a first unit volume (vol_a) or CED_vola.

Calculate the Combustive Energy Deficit (CED) of the first unit volume for the Initial Fuel Stock (IFS), by multiplying the Energy Density (ED) for the IFS for the first unit volume and subtracting that from the GED. (The unit volume subscript is suppressed as it is the same for all three elements of the equation.)

CED=GED−ED_IFS   EQ. 1

Calculate the Added Energy Density (AED) of the trioxynitrated n-alkane-based fuel additive for the same first unit volume; this may require converting across units of measurement (as in ounces, vol_b for gallons, vol_a):

AED÷vol_a=(HED÷vol_b)*(vol_b÷vol_a)   EQ. 2

For most purposes, a simple first approximation replacement is used, replacing on a per-unit basis an amount of the first unit volume, low-energy-density Initial Fuel Stock, with the same first unit volume HEDFA. Bounded calculus and other standard mathematical transformations for the recursive substitutions are well known in the prior art to smooth out the regression of substitution.

The extension to include a differential within the volume of the trioxynitrated n-alkane-based fuel additive between the high-energy-density compositive proportion and the other-functional compositive proportions is also asserted as a further embodiment of this method, since the energy densities of various xTONnAs can be varied. For example, the trioxynitrated n-alkane-based HEDFA of the preferred embodiment provides 97 times as much energy per unit volume as diesel when the xTONnA component is only 50% of the entirety of the fuel additive and a singly-trioxynitrated n-alkane. By changing the proportion of the HEDFA that is the xTONnA, or by increasing the number of trioxynitrate groups, the same volume can provide even more energy density and thus change the proportionate replacements required; thus, modifying the proportion of the xTONnA and of other components of the HEDFA to increase the energy density of the HEDFA will reduce the proportionate amount of the HEDFA required to make up the CED per unit volume a.

In yet another alternative, the additive is used in a blend of diesel that is to be 20% biodiesel and 80% diesel. (These values are chose because these are the ‘B-20’ standard, towards which the US is moving.) This embodiment will use the alternative fuel to be no more than 5% of the total diesel, which is the limit to the amount of an additive before disclosure is required. In another embodiment the biodiesel is a synthetic bio blend up to 50% of the BTU/unit volume is provide by the HEDFA and the balance of the BTU/unit volume is provided by the diesel or biodiesel.

In yet another alternative the additive is used in the manufacturing process whereby the original biodiesel is prepared, in which Biodiesel is defined by ASTM D 6751, which limits the residual methanol content to be called biodiesel, or by an external governmental standard (e.g. the EU specifies methanol content to be less than 0.2% or 2,000 ppm.). In these formulations the selection, blending, and concentration of alkanes depends upon the desired combustion efficiency of the targeted final biodiesel and the limitations imposed upon percentage of sub-composition which the additive must not exceed; since, however, the additive can be effective in as great a dilution as 1 part in 5,000, it can meet even the strict EU limitation.

Other materials can be substituted for the 2-Ethylhexyl Nitrate, including Rthyl Corporations mono-nitro and di-nitro compounds, peroxides, nitrates, nitrosocarbamates and assets of cyclodecyl nitrates and aliphatic hydrocarbyl nitro nitrates. But in the present invention the material used combine the performance benefits of increased energy density as well as elevating the Cetane number of the fuel.

The present embodiment using 2-Ethylhexyl Nitrate at a concentration of 40 to 60% is a main contributor to the 97 times increase in energy density over diesel. The present invention calls for implementation through mono-nitro, di-nitro and tri-nitro compounds attached to an alkane scaffold to make liquid fuels with extraordinarily high energy densities, avoiding the problems arising from a ring compound scaffold, where the attachment of multiple nitro compounds produces explosives such as TNT. Attaching one nitro group to an alkane scaffold will produce a fuel (speaking in exothermic reactive terms, not ‘in engine’ terms) that has approximately 100 times the energy density of gasoline when the 2-Ethylhexyl Nitrate is, as in the preferred embodiment, by volume 50% of the additive. Attaching two nitro groups to an alkane scaffold will, or is expected, to produce a fuel that has approximately 200 times the energy density of gasoline; and attaching three nitro groups to an alkane scaffold will or is expected to produce a fuel that has approximately 300 times the energy density of gasoline.

The preferred form of the two-nitrate group or di-nitro n-alkane is: 2-methyl-2nitro-1-propanol nitrate. An alternative means to reach or nearly reach the 200 times energy density is to increase the proportion of the 2-Ethylhexyl Nitrate to 100%, or as close as can be done while keeping other functional elements of this additive.

Blending such fuels so manufactured with methanol and biodiesel will produce low cost synthetic and bio-based alternative fuels that can be made from US feed stocks of the non-petrochemical origins to the greatest extent possible, serving the national goal of energy independence.

It can be seen to one skilled in the art that this invention makes producible a completed diesel fuel for diesel engines used in trucks, buses, train engines, off-road vehicles, heavy fueled aircraft, generators and furnaces, comprising as the base combustive energy mean, that blending of petroleum distillates selected from the group consisting of hydrocarbon distillates having a boiling point between 150 degrees C. (302 degrees F.) and 280 degrees C (716 degrees F.) that are selected; and, an additive mixture wherein the largest component is a energy-dense material that also serves as a Cetane Number improver that has a boiling point in the range of the diesel that is a mono-, di- or tri-trioxynitrated alkane consisting respectively of one, two or three nitro groups attached to a base n-alkane scaffold molecule (CH₂)_n where n is 2-20 and the trioxynitrate groups are either directly attached to the Alkane or attached via a branch (CH₂)_n,o,p where n is 2-20, o is not equal to n, and p is not equal to either n or o.

The detailing of the other components of the HEDFA for other functional purposes, such as additive elements for lubricity, anti-corrosion, antifungal, or other uses, as is known in the prior art, is disclosed therein and in the cited prior art forming a part of this application.

One skilled in the art of fuel additives is capable of taking the information provided and not only producing the fuel additive of the present invention but also understanding how logical extension by substituting other materials in the manufacture to obtain other final products that differ from this embodiment of the fuel additive that fall within the teaching of the present invention as to the resulting fuel additive that produces the favorable results claimed herein.

Claims

1. A multi-functional, high-energy-density fuel additive (HEDFA) to be mixed with a base fuel in a ratio ranging between one part of additive to 5,000 parts of base fuel, to one part of additive to 50 parts of base fuel to create a desired blended fuel, said HEDFA comprising: wherein the differentiated-mean combustive equivalencies and BTU/unit density values of the exothermic reactions of the base scaffolding n-alkane and the trioxynitrate group in combined combustion are sufficient to raise the energy density and improve performance of the base fuel as desired by mixing the HEDFA with the base fuel at the ratio producing the desired blended fuel's energy density.

at least a plurality by volume of a trioxynitrated n-alkane (xTONnA) for increasing the energy density of the base fuel, said xTONnA comprising: a base scaffolding n-alkane being any non-cyclic and non-aromatic and non-alkene hydrocarbon of the formula CnH2n+2 which has a BTU/unit energy density as a linear function of the number of carbons and less than the base fuel; and, at least one trioxynitrate group (NO3) attached to the base scaffolding n-alkane; and,

such additional components incorporating functional purposes other than increasing the energy density of the base fuel as desired according to the prior art;

2. A HEDFA as in claim 1 wherein only one trioxynitrate group (NO3) is attached to the base scaffolding n-alkane, limiting the combustive equivalency of the HEDFA to 1.7 to 2.0 million BTU per pound when the xTONnA is present at fifty percent by volume in the HEDFA.

3. A HEDFA as in claim 2 wherein the base scaffolding n-alkane to which at least one trioxynitrate is attached is the single largest ingredient in the HEDFA with the molecular linear formula CH3(CH2)(C2H5)CH2ONO2.

4. A HEDFA as in claim 2 wherein the xTONnA is 2-Ethylhexyl nitrate and comprises at least 40% of the HEDFA by volume, and the HEDFA comprises less than 0.4% by-volume of the desired blended fuel.

5. A HEDFA as in claim 1 wherein the xTONnA is 2-Methyl-2 nitro-1-propanol nitrate and comprises at least 40% of the HEDFA by volume.

6. A HEDFA as in claim 1 wherein two trioxynitrate groups are attached to the base scaffolding n-alkane, limiting the combustive equivalency of the HEDFA to between 1.7 million and 4 million BTU per pound when said xTONnA is present at fifty percent by volume in the HEDFA.

7. A HEDFA as in claim 6 further comprising: Component Concentration Volume, % 2-methyl-2nitro-1-propanol nitrate 40-60; Petroleum Distillates 25-30; 1,2,4-Trimethyl-benzene 3-7; Long Chain Alkyl Amide 3-7; m-Cresol 3-7; Xylenol 3-7; p-Cresol 5-6; Vinyl Acetate 5-6; and, Ethyl Phenols 2-5.

8. A HEDFA as in claim 1 wherein three trioxynitrate groups are attached to the base scaffolding n-alkane, delimiting the additive's combustive equivalency to between 4 million and 6 million BTU per pound when said xTONnA is present at fifty percent by volume in the HEDFA.

9. A HEDFA as in claim 8 further comprising at least one trioxynitrate group forming a high energy component, wherein the high energy component has an energy density measured in BTU per pound ranging from one half million to a maximum of ten million.

10. A HEDFA as in claim 1 wherein the xTONnA is sufficiently polar as to be miscible in either simple (non-isomeric) alcohols such as methanol, ethanol, propanol, and butanol, or standard diesel hydrocarbons without precipitating in the diesel hydrocarbons.

11. A HEDFA as in claim 1 wherein the base scaffolding n-alkane further comprises:

any combination of n-alkane-based, water-soluble simple alcohols having no more than two isomers, that is, any combination of methanol, ethanol, proponol, and butanol; and,

is manufactured from gases of geological or biomass origin and not from crude oil or petroleum distillates.

12. A HEDFA as in claim 11 wherein the alcohol is methanol and it as well as the mixture of components is manufactured from gases of geological or biomass origin and not from crude oil origin and not from petroleum distillate origin.

13. A HEDFA as in claim 1 used in a blend of diesel and biodiesel, said blend further comprising:

up to 20% by volume biodiesel;

<5% by volume multi-functional, high-energy-density fuel additive; and, the remainder diesel.

14. A HEDFA as in claim 1 used in a blend of diesel and biodiesel, said blend comprising that mixture wherein:

up to 50% of the BTU/unit volume is provide by the HEDFA; and,

the balance of the BTU/unit volume is provided by the diesel or biodiesel.

15. A multi-functional, high-energy-density fuel additive known as HEDFA prepared for petroleum-distillate base fuel blending in a ratio ranging between one part of additive to 5,000 parts of petroleum-distillate base fuel, to one part of additive to 50 parts of petroleum-distillate base fuel, to create a desired blended fuel, said HEDFA having a composition in the following range: Component Concentration Volume, % 2-Ethylhexyl Nitrate 40-60; Petroleum Distillates 25-30; 1,2,4-Trimethyl-benzene 3-7; Long Chain Alkyl Amide 3-7; m-Cresol 3-7; Xylenol 3-7; p-Cresol 5-6; Vinyl Acetate 5-6; and, Ethyl Phenols 2-5.

16. A HEDFA as in claim 15 prepared for blending with a petroleum-distillate base diesel fuel with an average Cetane number of 38-55 to provide an improvement of at least 4 Cetane Numbers, said HEDFA comprising: Component Name Concentration Volume(%) 2-Ethylhexyl Nitrate 50;  Petroleum Distillates  18.4; 1,2,4-Trimethyl-benzene 5; Long Chain Alkyl Amide 5; m-Cresol 5; Xylenol 5; p-Cresol 4; Vinyl Acetate 4; and, Ethyl Phenols   3.6.

17. A multi-functional, high-energy-density fuel additive known as HEDFA prepared for blending with a petroleum-distillate base diesel fuel with an average Cetane number of 38-55 to provide an improvement of at least 4 Cetane Numbers once blended, with said composition being for a Non p-Cresol formulation and comprising: Component Name % by Weight Ethylhexyl Nitrate 40-60%  Solvent Naphtha, Petroleum, 5-15% Heavy Arom. Ethylene Glycol Monobutyl Ether 5-15% Solvent Naphtha, Petroleum, <5% Light Arom. 1,2,4-Trimethylbenzene <5% Naphthalene <2% Xylene <0.5%; and, Ethylbenzene <0.1%.   

18. A method for preparing from an initial fuel stock that has a particular energy density, and a multi-functional, high-energy-density fuel additive (HEDFA) comprising a base scaffolding n-alkane and at least one trioxynitrate attached thereto (xTONnA) with a proportion of other components, a final blended fuel for a goal energy density (GED) and combustive efficiency, said method comprising: to produce the proportionate amount of the multi-functional fuel additive that; when substituted for the same volume of initial fuel stock, will make up the GED per unit volume a.

setting the goal energy density per unit volume a (‘GED/vola’) for the final blended fuel;

calculating the combustive energy deficit per unit volume a (‘CED’) of the initial fuel stock by subtracting from the GED the particular energy density of the initial fuel stock per vola; and,

dividing the CED by the HEDFA;

19. A method as in claim 18, wherein the initial fuel stock is any mixture of methanol and ethanol derived from renewable or natural gas sources, the final proportionate amount of HEDFA is limited to less than 2 ounces by volume per gallon, wherein the volume required decreases as the number of nitro group attached to the alkane scaffold increases, and additional additives are contain in the mixture to improve lubricity, inhibit corrosion and other additives to form a fuel for gasoline or diesel engines or a combustion furnace.

20. A method in claim 19 where the principal component of the HEDFA is 2-Ethylhexyl nitrate.

21. A method in claim 19 where the principal component of the HEDFA is 2-Methyl-2 nitro-1-propanol nitrate.

22. A method in claim 19 where the principal component of the HEDFA is an alkane scaffold containing three nitro groups.

23. A method as in claim 18, further comprising a step of modifying the proportion of the xTONnA and of other components of the HEDFA to increase the energy density of the HEDFA and thus reduce the proportionate amount of the HEDFA required to make up the CED per unit volume a.

24. A completed diesel fuel for diesel engines used in trucks, buses, train engines, off-road vehicles, heavy fueled aircraft, generators and furnaces, further comprising:

as the base combustive energy mean, that blending of petroleum distillates selected from the group consisting of hydrocarbon distillates having a boiling point between 150 degrees C. (302 degrees F.) and 280 degrees C. (716 degrees F.) that are selected; and,

an additive mixture wherein the largest component is a energy-dense material that also serves as a Cetane Number improver that has a boiling point in the range of the diesel that is a mono-, di- or tri-trioxynitrated alkane consisting respectively of one, two or three nitro groups attached to a base n-alkane scaffold molecule (CH2), where n is 2-20 and the trioxynitrate groups are either directly attached to the Alkane or attached via a branch (CH2)n,o,p where n is 2-20, o is not equal to n, and p is not equal to either n or o.

25. A class of molecular combinations that are sufficient stable to be used as fuels for combustion in engines or furnaces having a non-alkene, non-ring, non-aromatic n-alkane as base scaffolding and a minimum of one and a maximum of three trioxynitrate (xTONnA), wherein the non-alkene, non-ring, non-aromatic n-alkane base scaffolding contains only stable saturated bonds that do not detonate during combustion as is the case when trinitrotoluene combusts.