MXPA05001756A - Method of reducing amount of peroxides, reducing fuel sediment and enhancing fuel system elastomer durability, fuel stability and fuel color durability - Google Patents

Abstract

A reduction in the formation and presence of peroxides in low sulfur diesel fuels is obtained through the combination of those fuels with an organic nitrate combustion improver. The reduction in the amount of peroxides means that the fuel system elastomers will be more durable, as they are not being corroded by as much peroxide formed in the fuel, fuel color durability is improved, fuel stability is enhanced, and fuel sediments are reduced.

Description

METHOD TO REDUCE THE AMOUNT OF PEROXIDES, REDUCE FUEL SEDIMENTS AND IMPROVE THE DURABILITY OF THE ELASTOMER OF FUEL SYSTEM, FUEL STABILITY AND FUEL COLOR DURABILITY FIELD OF THE INVENTION This invention relates to a method for including the addition of an organic nitrate combustion improver to a medium distillate fuel, to reduce the formation or presence in the fuel of peroxides. In particular, in low or ultra-low sulfur fuels, the addition of an organic nitrate combustion improver, for example 2-ethylhexyl nitrate, retards the formation and / or reduces the presence of peroxides, and prolongs life of joints, hoses, seals and other elastomeric parts exposed to peroxides. Other benefits include a reduction in fuel sediments and improvement in fuel stability and color durability. BACKGROUND OF THE INVENTION There is a current trend towards the use of ultra low sulfur diesel fuels, commonly referred to as fuels having 50 ppm sulfur or less ("ULSD fuels"). This trend towards the use of ULSD fuels has caused substantial changes in the combustion system and also significant changes REF .: 161787 in fuel specifications. Many industrialized nations are reducing and / or have already reduced their mandatory maximum specifications with respect to the sulfur content. As a result, there are new concerns regarding the performance and handling of fuels formulated to meet the new specifications. One concern with ULSD fuels is that the removal of sulfur compounds, some of which are effective sequestrants and / or substances that decompose peroxide, can allow peroxides to accumulate in these fuels. The increased potential in peroxides is detrimental to fuel systems, because peroxides are known to degrade the elastomers of fuel systems. Therefore, the increase in peroxides can cause the possible fracture of seals, gaskets and hoses in a fuel system that uses ULSD fuels. See, for example, Owen and Coley, Automotive Fuels Reference Book, Second Edition, 1995, p. 520-523. The potential seriousness of this problem is well documented in the problems with combustion turbine fuels in the 1960s and 1970s, where the high peroxide content in these fuels was associated with a high failure rate for fuel hoses, joints and seals in these systems. For example, Fodor, et al., "Peroxide Formation in Jet Fuels", Energy and Fuels, 1988, pp. 729-34. Other concerns that arise when peroxide levels increase include fuel stability, color durability and fuel sediments. These concerns are discussed in general in Bacha and Lesnini, "Diesel Fuel Thermal Stability at 300 ° F," Sixth International Conference on Stability and Handling of Liquid Fuels, Vancouver, Canada, October 13-17, 1997; Vardi and Kraus, "Peroxide Formation in Low Sulfur Automotive Diesel Fuels", SAE Document no. 920826. It is conventionally known that combustion improvers such as organic nitrate combustion improvers can affect peroxide formation. It has been observed that combustion improvers can in fact promote the formation of peroxides at relatively higher temperatures. This observation is assumed true for all temperatures. Therefore, there is a possible concern that ULSD fuels, and particularly those containing combustion improvers, may be prone to form harmful levels of peroxides and hydroperoxides during storage. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a diagram that characterizes the fuels that were tested as described herein. Figure 2 is a graph showing the kinetics of the hydroperoxide of the fuels tested as described herein. DETAILED DESCRIPTION OF THE INVENTION A reduction in the formation or presence of peroxides and hydroperoxides in ultra low sulfur diesel fuels, is obtained through the combination of an organic nitrate combustion improver with the fuel. By reducing the amount and / or formation of peroxides and hydroperoxides, it is possible to improve the durability of middle distillate fuel system elastomers, improve fuel stability, improve color durability and reduce fuel sediment formation .

It is believed that the interaction between organic nitrate combustion improvers and the peroxides / hydroperoxides includes a mechanism that is temperature dependent. The "peroxides" are understood to include in the present, peroxides, hydroperoxides, mixtures thereof and precursors thereof. As demonstrated in the tests discussed here, fuels containing organic nitrate combustion improvers have actually increased peroxide levels over time, compared to fuels without any organic nitrate combustion improver, but only at high levels. temperatures (temperatures greater than about 70 ° C). In general, this discovery of a greater amount of peroxides resulting from the use of organic nitrate combustion improvers is consistent with conventional teaching. However, it has been found that at temperatures below about 70 ° C, there is in fact an unexpected reduction in the amount or formation of peroxides when an organic nitrate combustion improver is combined with a ULSD fuel. A method for reducing the amount of peroxides in medium, low sulfur distillate fuels comprises the steps of: providing an average distillate fuel having a sulfur content of about 50 ppm or less; combine the fuel with a better organic nitrate combustion; wherein the amount of organic nitrate combustion combined with the fuel reduces the amount of peroxides in the fuel, compared to an average distillate fuel without the organic nitrate combustion improver. Fuels are rarely stored at temperatures of approximately 70 ° C or higher. If a fuel reaches this temperature in the operation of a combustion system, then the fuel would remain only at this temperature for a very short time before combustion. As a result, a relatively insignificant increase in the presence and / or formation of peroxide would result, if at all, from the use of an organic nitrate combustion improver. More importantly, medium distillate fuel can often be stored for days / weeks / months before use. Typical storage temperatures would be well below 70 ° C. Therefore, in a realistic manner, it is significant that an organic nitrate combustion improver is found to retard the formation of or reduce the amount of peroxides in ULSD fuels. A presentation entitled "Hydroperoxide Formation in Ultra-Low Sulfur Diesel Fuels" by Joshua J. Bennett and Scott D. Schwab, prepared for the International Conference on Stability and Handling of Liquid Fuels, Steamboat Springs, Colorado on September 19, 2003. Such presentation and the materials presented are incorporated herein by reference which are set forth in their entirety. The hydrocarbon fuels used herein are, in general, comprised of hydrocarbon mixtures that fall within the distillation range of about 160 to about 370 ° C. Such fuels are often referred to as "middle distillate fuels" since they comprise the fractions that distill after gasoline. Such fuels include diesel fuels, biodiesel and fuels derived from biodiesel, fuel for burners, kerosene, diesel, fuels for combustion turbines and fuels for gas turbine engines.

In one embodiment, the applicable middle distillate fuels are those characterized in that they have the following distillation profile: Diesel fuels having a net cetane number (ie, a cetane number when devoid of any cetane improver, such as an organic nitrate) in the range of 30 to 60 can also be used. In another example, they are Those in which the net cetane number is in the range of 40 to 50. The organic nitrate combustion mej ers (often also known as ignition mech orators) comprise nitrate esters of aliphatic or substituted or unsubstituted cycloaliphatic alcohols. which can be monohydric or polyhydric. The organic nitrates may be substituted or unsubstituted alkyl or cycloalkyl nitrates having up to about 10 carbon atoms, for example from 2 to 10 carbon atoms. The alkyl group may be either linear or branched (or a mixture of linear or branched alkyl groups). Specific examples of nitrate compounds suitable for use as nitrate combustion improvers include, but are not limited to the following: methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl nitrate, nitrate allyl, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate, isoamyl nitrate, 2-membered nitrate, 3-amyl nitrate, nitrate amyl, n-hexyl nitrate, n-heptyl nitrate, sec-heptyl nitrate, n-octyl nitrate, 2-ethylhexyl nitrate, sec-octyl nitrate, n-nonyl nitrate, n-decyl nitrate, cyclopentyl nitrate, cyclohexyl nitrate, methylcyclohexyl nitrate, isopropylcyclohexyl nitrate and the like. Also suitable are the nitrate esters of aliphatic alcohols substituted with alkoxy, such as 2-ethoxyethyl nitrate, 2- (2-ethoxyethoxy) ethyl nitrate, 1-methoxypropyl-2-nitrate and 4-ethoxybutyl nitrate, as well as nitrates. of diols, such as 1, 6-hexamephylene dinitrate and the like. For example, nitrates and alkyl dinitrates having from 5 to 10 carbon atoms are also included, and more especially mixtures of primary amyl nitrates, mixtures of primary hexyl nitrates and octyl nitrates, such as 2-ethylhexyl nitrate. As is well known, nitrate esters are usually prepared by nitration of the mixed acid of the appropriate alcohol or diol. In general, mixtures of nitric and sulfuric acids are used for this purpose. Another way to synthesize the nitrate esters involves the reaction of an alkyl or cycloalkyl halide with silver nitrate. The concentration of the nitrate ester or other organic nitrate combustion mezzanine in the middle distillate fuel can be varied within relatively wide limits, so that the amount employed is at least sufficient to cause a reduction in the presence and / or formation of peroxides. This amount may fall within the range of 100 to 5,000 parts by weight per parts per million of fuel. Other additives may be included within the fuel compositions described herein, provided that they do not adversely affect the amount or formation of the otherwise obtained peroxides herein. Thus, one or more such components may be used as corrosion inhibitors, antioxidants, anti-mildew agents, detergents and dispersants, fuel lubricant additives, demulsifiers, colorants, inert diluents, cold flow improvers, conductivity agents. , metal deactivators, stabilizers, antifoam additives, anti-icing agents, biocides, odorants, slag reducers, combustion improvers, for example, including MMT, oxygenates and similar materials. These additives can also be used in combinations such as additive packaging. The sulfur compounds themselves can reduce the amount of peroxide in a fuel, so that the present analysis refers to low sulfur fuels. For example, ultra-low sulfur fuels containing the organic nitrate combustion engine can have less than about 100 ppm sulfur, or alternatively, less than about 50 ppm sulfur. Still further alternatives include fuels having less than about 20 ppm or less than about 10 ppm sulfur. The advantages gained from the addition of an organic nitrate combustion improver to a low sulfur fuel are demonstrated in the following tests. For the purposes of these tests, it appears to be detrimental to have a peroxide concentration greater than about 8 ppm. Therefore, the measurements made here were with respect to the time / temperature conditions of specific fuels, which result in a concentration of a peroxide greater than about 8 ppm. First, two different fuels were tested. These fuels were identified as Fuel A and Fuel B. Fuels that have significantly different properties were identified to better evaluate how different fuels may have different results. Figure 1 defines the two fuels A and B that were used in the test.

Fuels A and B were each tested with and without the addition of 2500 ppm of combustion improver of 2-ethylhexyl nitrate. As a result of the test on the machine, the precise conditions of the fuel (temperature and residence time) that generate harmful concentrations (greater than 8 ppm) of peroxides were determined. Given the known points on the graph, the lines were calculated to represent the kinetics of peroxide formation. The specific kinetics of the peroxide that were indicated are shown in Figure 2. As is evident from the kinetics shown in Figure 2, fuels containing the organic nitrate combustion improver (e.g., 2-EHN) demonstrate each a longer time to reach a harmful peroxide level when the fuel temperatures are less than about 70 ° C. The specific temperature at which such levels of harmful peroxides would occur would be the intersection of the linear kinetics demonstrated for fuels with and without the organic nitrate combustion mej. The organic nitrate combustion improver with a medium distillate fuel allows each of: (1) elastomer durability benefit, (2) improved fuel stability, (3) fuel sediment reduction and (4) improvement in color durability while maintaining the amount of peroxides in ULSD fuels of less than about 8 ppm. Based on the above tests and calculations, it is observed that the formation and / or presence of peroxide (i.e., the amount of peroxide) is reduced in the middle distillate fuels containing an organic nitrate combustion improver. This can be a significant benefit to prolong the life of elastomeric materials in contact with fuels when fuels are stored for long periods of time. Other benefits include improved fuel stability, color durability and a reduction in fuel sediments. The durability of elastomers susceptible to degradation from exposure to peroxides in a fuel system is expected to be extended or improved by at least 25% in terms of miles traveled, gallons of fuel burned or days / years of service, compared to the durability of the elastomers in a fuel system that does not contain an organic nitrate combustion mej. In another embodiment, the durability of the elastomer is extended or improved by at least 10%, compared to the durability of elastomers exposed to fuels that do not contain an organic nitrate combustion improver. In this way, it is expected that the fuel stability of a middle distillate fuel can be extended or improved by at least 25% in terms of miles traveled, gallons of fuel burned or days / years of service, compared to fuel stability of a fuel that does not contain an organic nitrate combustion mej. In another embodiment, fuel stability is extended or improved by at least 10%, compared to the stability of fuels that do not contain an organic nitrate combustion improver. In this way, it is expected that the durability of fuel color can be extended or improved by at least 25% in terms of miles traveled, gallons of fuel burned or days / years of service, compared to the durability of fuel color in a fuel that does not contain an organic nitrate combustion mej. In another embodiment, the durability of the fuel color is expected to be extended or improved by at least 10%, compared to the durability of fuels that do not contain an organic nitrate combustion improver. It is expected that the formation or presence of fuel sediment will be reduced by at least 25% in terms of miles traveled, gallons of burned fuel or days / years of service, compared to the amount of fuel pellets in a fuel that does not contain an organic nitrate combustion improver. In another embodiment, the amount of fuel pellets is reduced or improved by at least 10%, compared to the amount of fuel pellets that do not contain an organic nitrate combustion improver. It is understood that the reagents and components referred to by the chemical name anywhere in the specification or claims thereof, whether referenced in singular or plural, are identified as they exist before coming into contact with another substance referred to by the chemical name or by the chemical type (for example, base fuel, solvent, etc.). It does not matter what changes, transformations and / or chemical reactions, if any, are carried out in the resulting mixture or solution or reaction medium, since such changes, transformations and / or reactions are the natural result of gathering the reactants and / or components specified under the conditions required to continue with this description. In this manner, the reagents and components are identified as ingredients to meet either in the development of a desired chemical reaction or in the formation of a desired composition (such as an additive concentrate or a fuel mixture with additives). It will also be recognized that the additive components can be added or mixed in or with the base fuels individually per se and / or as the components used in the formation of preformed additive combinations and / or sub-combinations. Therefore, although the subsequent claims may refer to substances, components and / or ingredients in the present phrase ("comprises", "is", etc.), the reference is to the substance, components or ingredient, as it exists in the moment just before it was combined or mixed first with one or more other substances, components and / or ingredients according to the present disclosure. The fact that the substance, constituents or ingredient may have lost their original identity through a chemical reaction or transformation during the course of such combined or mixed operations or immediately thereafter, is thus completely immaterial to an understanding and appreciation of this description and the claims thereof. In numerous parts throughout this specification, reference is made to a number of technical documents. All the aforementioned documents are expressly incorporated in their entirety in this description as if they were fully established therein. This invention is susceptible to considerable variation in its practice. Therefore, the above description is not intended to limit it, and should not be construed as limiting the invention to the particular exemplifications presented above. Rather, what is intended to cover is as established in the following claims and the equivalents thereof allowed as a matter of law. The owner of the patent does not intend to dedicate any modalities described to the public, and for such purpose, any modifications or alterations described can not fall literally within the scope of the claims, these are considered to be part of the invention in accordance with the doctrine of equivalents It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (53)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A method for reducing the amount of peroxides in middle distillate fuels, low in sulfur, characterized in that it comprises the steps of: providing a distillate fuel medium having a sulfur content of about 50 ppm or less; combine the fuel with a better organic nitrate combustion; wherein the amount of organic nitrate combustion combined with the fuel reduces the amount of peroxides in the fuel compared to an average distillate fuel without the organic nitrate combustion improver.
2. 2. A method as described according to claim 1, characterized in that the organic nitrate combustion improver comprises 2-ethylhexyl nitrate.
3. 3. A method as described according to claim 2, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 100 to 5000 ppm by weight of the fuel.
4. 4. A method as described according to claim 3, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 2500 ppm by weight of the fuel.
5. 5. A method as described in claim 1, characterized in that the middle distillate fuel is selected from the group consisting of diesel fuel, biodiesel fuel, burner fuel, kerosene, diesel fuel, fuel for combustion turbines and fuel for gas turbine engines.
6. 6. A method as described according to claim 1, characterized in that the fuel has a sulfur content of about 20 ppm or less.
7. 7. A method as described according to claim 1, characterized in that the fuel has a sulfur content of about 10 ppm or less.
8. A method as described according to claim 1, characterized in that the fuel further comprises one or more components selected from the group consisting of: corrosion inhibitors, antioxidants, anti-mildew agents, detergents and dispersants, fuel lubricant additives. , de-emulsifiers, colorants, inert diluents, cold flow improvers, conductivity agents, metal deactivators, stabilizers, antifoam additives, de-icers, biocides, odorants, slag reducers, combustion improvers, MMT and oxygenates.
9. A method for improving the durability of elastomers of the middle distillate fuel system, characterized in that it comprises the steps of: providing an average distillate fuel having a sulfur content of about 50 ppm or less; combine the fuel with a better organic nitrate combustion; wherein the amount of organic nitrate combustion fuel combined with the fuel improves the durability of the middle distillate fuel system elastomers compared to the durability of elastomers in a medium distillate fuel system that burns a medium distillate fuel without the organic nitrate combustion improver.
10. A method as described according to claim 9, characterized in that the organic nitrate combustion improver comprises 2-ethylhexyl nitrate.
11. 11. A method as described according to claim 10, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 100 to 5000 ppm by weight of the fuel.
12. 12. A method as described according to claim 10, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 2500 ppm by weight of the fuel.
13. A method as described according to claim 9, characterized in that the middle distillate fuel is selected from the group consisting of diesel fuel, biodiesel fuel, fuel for burners, kerosene, diesel fuel, fuel for combustion turbines and fuel for gas turbine engines.
14. A method as described according to claim 9, characterized in that the fuel has a sulfur content of about 20 ppm or less.
15. 15. A method as described according to claim 9, characterized in that the fuel has a sulfur content of about 10 ppm or less.
16. 16. A method as described in claim 9, characterized in that the fuel further comprises at least one component selected from the group consisting of: corrosion inhibitors, antioxidants, anti-mildew agents, detergents and dispersants, lubricating additives of fuel, demulsifiers, colorants, inert diluents, cold flow improvers, conductivity agents, metal deactivators, stabilizers, antifoam additives, anti-icing agents, biocides, odorants, slag reducers, combustion improvers, MMT and oxygenates.
17. 17. A method as described according to claim 1, characterized in that the amount of peroxides in the fuel is less than about 8 ppm.
18. 18. A method as described according to claim 9, characterized in that the amount of peroxides in the fuel is less than about 8 ppm.
19. 19. A method as described according to claim 9, characterized in that the durability of the elastomers is improved by up to 25% measured in miles traveled, gallons of fuel burned or days / years of service, with respect to the durability of the elastomers in a combustion fuel of the middle distillate fuel system without an organic nitrate combustion improver.
20. 20. In a medium distillate fuel combustion system, characterized in that it comprises one or more elastomers susceptible to degradation by exposure to peroxides, the improvement in the durability of the elastomer is obtained by including the fuel burned in the system in a quantity of cleaner. of sufficient organic nitrate combustion to produce a quantity of peroxides therein, or less than about 8 parts per million in the fuel.
21. 21. A method for improving the color durability of a middle distillate fuel, characterized in that it comprises the steps of: providing an average distillate fuel having a sulfur content of about 50 ppm or less; combine the fuel with a better organic nitrate combustion; wherein the amount of organic nitrate combustion improver combined with the fuel improves the color durability of the middle distillate fuel compared to the color durability of an average distillate fuel without the organic nitrate combustion improver.
22. 22. A method as described according to claim 21, characterized in that the organic nitrate combustion improver comprises 2-ethylhexyl nitrate.
23. 23. A method as described according to claim 22, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 100 to 5000 ppm by weight of the fuel.
24. 24. A method as described according to claim 22, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 2500 ppm by weight of the fuel.
25. 25. A method as described in claim 21, characterized in that the middle distillate fuel is selected from the group consisting of diesel fuel, biodiesel fuel, burner fuel, kerosene, diesel fuel, fuel for combustion turbines and fuel for gas turbine engines.
26. 26. A method as described according to claim 21, characterized in that the fuel has a sulfur content of about 20 ppm or less.
27. 27. A method as described according to claim 21, characterized in that the fuel has a sulfur content of about 10 ppm or less.
28. A method as described according to claim 21, characterized in that the fuel further comprises one or more components of the group consisting of: corrosion inhibitors, antioxidants, anti-mildew agents, detergents and dispersants, fuel lubricant additives, demulsifiers, colorants, inert diluents, cold flow improvers, conductivity agents, metal deactivators, stabilizers, antifoam additives, anti - icing agents, biocides, odorants, slag reducers,. combustion, MMT and oxygenates.
29. 29. A method as described according to claim 21, characterized in that the amount of peroxides in the fuel is less than about 8 ppm.
30. 30. A method as described according to claim 21, characterized in that the durability of the color of the fuel is improved by up to 25% measured in miles traveled, gallons of fuel burned or days / years of service, with respect to the durability of the color of the fuel. fuels without an organic nitrate combustion improver.
31. 31. In a medium distillate fuel combustion system, characterized by comprising a fuel color susceptible to degradation by exposure to peroxides, the improvement in the durability of the color is obtained by including the fuel burned in the system in an amount of combustion improver of organic nitrate sufficient to produce a quantity of peroxides in the same, or less than about 8 parts per million in the fuel .
32. 32. A method for improving the fuel stability of a middle distillate fuel, characterized in that it comprises the steps of: providing an average distillate fuel having a sulfur content of about 50 ppm or less; combine the fuel with a better organic nitrate combustion; wherein the amount of organic nitrate combustion fuel combined with the fuel improves the fuel stability of the middle distillate fuel compared to the stability of the fuel of a middle distillate fuel without the organic nitrate combustion mej.
33. 33. A method as described according to claim 32, characterized in that the organic nitrate combustion engine comprises 2-ethylhexyl nitrate.
34. 34. A method as described according to claim 33, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 100 to 5000 ppm by weight of the fuel.
35. 35. A method as described according to claim 33, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 2500 ppm by weight of the fuel.
36. 36. A method as described in claim 32, characterized in that the middle distillate fuel is selected from the group consisting of diesel fuel, biodiesel fuel, burner fuel, kerosene, diesel fuel, fuel for combustion turbines and fuel for gas turbine engines.
37. 37. A method as described according to claim 32, characterized in that the fuel has a sulfur content of about 20 ppm or less.
38. 38. A method as described according to claim 32, characterized in that the fuel has a sulfur content of about 10 ppm or less.
39. 39. A method as described according to claim 32, characterized in that the fuel further comprises one or more components selected from the group consisting of: corrosion inhibitors, antioxidants, anti-mildew agents, detergents and dispersants, fuel lubricant additives. , demulsifiers, colorants, inert diluents, cold flow improvers, conductivity agents, metal deactivators, stabilizers, antifoam additives, anti-icing agents, biocides, odorants, slag reducers, combustion improvers, MMT and oxygenates.
40. 40. A method as described according to claim 32, characterized in that the amount of peroxides in the fuel is less than about 8 ppm.
41. 41. A method as described according to claim 32, characterized in that fuel stability is improved by up to 25% measured in miles traveled, gallons of fuel burned or days / years of service, relative to fuel fuel stability. without an organic nitrate combustion mej.
42. 42. A medium distillate fuel, characterized in that it has a fuel stability susceptible to degradation by exposure to peroxides, the improvement in fuel stability is obtained by including in the fuel an amount of organic nitrate combustion improver sufficient to produce an amount of peroxides therein, or less than about 8 parts per million in the fuel.
43. 43. A method for reducing fuel pellet in a middle distillate fuel, characterized in that it comprises the steps of: providing an average distillate fuel having a sulfur content of about 50 ppm or less; combine the fuel with a better organic nitrate combustion; wherein the amount of organic nitrate combustion improver combined with the fuel reduces the fuel pellets in the middle distillate fuel, compared to the fuel pellets in a middle distillate fuel without the organic nitrate combustion improver.
44. 44. A method as described according to claim 43, characterized in that the organic nitrate combustion engine comprises 2-ethylhexyl nitrate.
45. 45. A method as described according to claim 44, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 100 to 5000 ppm by weight of the fuel.
46. 46. A method as described according to claim 43, characterized in that the 2-ethylhexyl nitrate is combined in an amount of about 2500 ppm by weight of the fuel.
47. 47. A method as described according to claim 43, characterized in that the middle distillate fuel is selected from the group consisting of diesel fuel, biodiesel fuel, burner fuel, kerosene, diesel fuel, fuel for combustion turbines and fuel for gas turbine engines.
48. 48. A method as described according to claim 43, characterized in that the fuel has a sulfur content of about 20 ppm or less.
49. 49. A method as described in accordance with claim 43, characterized in that the fuel has a sulfur content of about 10 ppm or less.
50. 50. A method as described according to claim 43, characterized in that the fuel further comprises one or more components of the group consisting of: corrosion inhibitors, antioxidants, anti-mildew agents, detergents and dispersants, fuel lubricant additives, demulsifiers, colorants, inert diluents, cold flow improvers, conductivity agents, metal deactivators, stabilizers, antifoam additives, anti-icing agents, biocides, odorants, slag reducers, combustion improvers, MMT and oxygenates.
51. 51. A method as described according to claim 43, characterized in that the amount of peroxides in the fuel is less than about 8 ppm.
52. 52. A method as described in claim 43, characterized in that the fuel pellet is reduced by up to 25% measured in miles traveled, gallons of fuel burned or days / years of service, relative to the fuel pellet in a fuel without a combustion meter of organic nitrate.
53. 53. In a medium distillate fuel combustion system, characterized in that it is susceptible to forming fuel pellets by exposure to peroxides, the improvement in the reduction in the formation of fuel pellets is obtained by including in the fuel burned in the system, an amount of organic nitrate combustion improver sufficient to produce an amount of peroxides therein, less than about 8 ppm in the fuel.