BRPI0620432A2 - Fuel additive for increasing the combustion characteristics of a high carbon asphaltene fuel, a method to improve its characteristics and fuel - Google Patents

Abstract

FUEL ADDITIVE FOR INCREASING THE COMBUSTION CHARACTERISTICS OF A HIGH ASPHALTENE CARBONED FUEL, METHOD FOR IMPROVING THE SAME AND COMBUSTIBLE CHARACTERISTICS. Additives for high-asphaltene carbon fuels, such as residual fuel oil or mineral coal, are described. These additives provide improved combustion characteristics. These improved combustion characteristics include one or both of increased efficiency and reduced pollutant emissions. Specifically, fuel additives include an extract from a plant such as fescue, alfalfa or alfalfa and optionally, an organometallic compound. The use of a fuel additive that includes both a plant extract and an organometallic compound is specifically useful in improving the combustion characteristics of fuels with specifically high asphaltene content.

Description

Report of the Invention Patent for "FUEL ADDITIVE FOR INCREASING FUEL CHARACTERISTICS OF A HIGH ASPHALTEN CARBON FUEL, METHOD FOR IMPROVING SAME AND FUEL CHARACTERISTICS".

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims the benefits of Provisional Patent Application No. 60 / 753,318, filed December 21, 2005, the full description of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to fuel additives for coal fuels that have a high asphaltene content such as residual fuel oil and coal. Advantages with respect to the use of such fuel additives may include one or more reduced particulate matter emissions, reduced nitrogen oxide emissions, and increased combustion efficiency.

BACKGROUND OF THE INVENTION

High asphaltene carbonaceous fuels such as waste fuel oil and coal tend to release large amounts of energy in combustion and therefore find utility in applications where low cost and high energy are desired. gia. However, such high asphaltene carbonaceous fuels burn and generally less effectively than other hydrocarbon fuels and may almost always contain amounts of undesirable compounds that limit combustion and result in high levels of pollutants.

Residual combustible oils (also referred to as "waste" or "waste fuel") are generally low quality products that remain after distillation of lighter petroleum products which may include gasoline, jet fuel , diesel fuel, No. 4 fuel oil and No. 5 heavy or light oil. Examples of residual fuel oils include No. 6 fuel oil and Bunker C fuel oil.

Compounds referred to as "asphaltenes" include, and generally, aromatic and / or polycyclic polynuclear materials. While certain parts of the world such as North America tend to have specifications that limit the amount of asphaltenes in fuels such as residual fuel oil, these fuels still have relatively high levels of asphaltenes when compared to other fuels. lighter hydrocarbon. For example, in the United States, specifications limit the asphaltene content of residual fuel oil to less than about 8% by weight. However, in other parts of the world, asphaltene specifications tend to be either non-existent or significantly higher than those in North America. For this reason, residual fuel oils in other parts of the world may have aste- ment contents of 10% by weight or higher. As a reasonably heavy carboniferous fuel, coal also tends to have high ring structure concentrations that may include anthracene and phenanthrene which for the purposes of this specification are to be included as "astenances". It should be noted that as coal becomes "older", more of these rings form and become interconnected such that coal can also be considered a high asphaltene coal fuel.

For the purposes of this descriptive report, the phrase "high asphaltene carboniferous fuel" is intended to cover broadly carboniferous fuels having an asphaltene content of at least 4% by weight.

Examples of pollutants that may result from the combustion of high asphaltene carbonaceous fuels include ozone, particulate matter (PM), carbon monoxide, nitrogen oxides (NO2) sulfur dioxide, polynuclear aromatic compounds, and soluble organic fractions. In the United States, numerous state and national agencies have adopted or are adopting ambient air quality standards that may require emission reductions from the combustion of high asphaltene coal fuels. Among the users of oil resides are power manufacturing facilities, and ocean vessels. In Southern California, for example, emissions from ships entering the port of Los Angeles are considered to be the leading cause of regional air pollution.

Considerable effort has been expended by oil refiners in formulating emissions-reducing fuels. The most common approach to formulating compliant fuels involves adjusting refinery processes to produce a fuel that meets the specifications determined by the appropriate government agencies. However, this approach is difficult with respect to waste fuels, and the difficulties with this approach include high costs in reconfiguring refinery processes and possible negative effects on the quality of other refinery products.

SUMMARY OF THE INVENTION

Embodiments of the present invention include systems, methods, and compositions that may provide improved combustion characteristics of high asphaltene coal fuels. Examples of the characteristics and combustion that can be improved by the embodiments of the invention include one or both of the increased combustion efficiency, and the reduction in pollutant discharge. Examples of pollutants that may be reduced include one or more ozone, particulate matter (PM), carbon monoxide, nitrogen oxides (NO2) sulfur dioxide, polynuclear aromatic compounds, and soluble organic fractions.

In some embodiments, a fuel additive comprising a plant extract is provided. In this descriptive report, the term "plant extract" is intended to broadly encompass extracts of all types of plants, excluding roots and cortex, and even including plants such as algae. Suitable plant extracts from green and other color plants such as these plants tend to have high concentrations of desirable extracts. However, even light-colored white plants include these extracts, albeit at lower concentrations. Specifically suitable extracts are from green plants and dark green leafy plants, such as those in the Leguminosae family, which include fescue, alpine, and alfalfa.

In one embodiment, the plant extract is combined with an organometallic material. The inclusion of an organometallic compound is especially useful for treating fuels having specifically high asphaltene contents in the range of 8 wt.% Or higher. Examples of organometallic materials are hydrocarbon-soluble organometallic compounds that include a metal selected from the first and second rows of transition metals. One metal of particular interest is iron, and particularly suitable organometallic materials include iron pentacarbonyl, iron naphthenate, ferroene and combinations thereof. The fuel additive may optionally include an oil soluble vehicle. Examples of oil soluble vehicles include hydrocarbons such as toluene, aromatic combinations, naphtha, gasoline, diesel fuel, jet fuel and mixtures thereof. In one embodiment, the oil soluble carrier is unoxygenated.

In certain embodiments, the fuel additive may include other optional ingredients. These optional ingredients may include one or more of an oxygen carrier, a stability aid, a lubricity aid, and an antioxidant. Meadowfoam oil can be used as a stability aid, an antioxidant, a lubricity aid. Suitable oxygen vehicles include carotenoids. Examples of antioxidants include 1,2-dihydroquinolines, and specifically 2,2-trimethyl-6-ethoxy-1,2-dihydroquinoline. Examples of combustion enhancers include compounds known as cetane improvers or ignition accelerators. Examples of combustion enhancers include alkyl nitrates, such as 2-ethylhexyl nitrate.

In another embodiment of the present invention, a method for improving the combustion characteristics of a high asphaltene carbonaceous fuel comprises the addition of a fuel additive as described above to a high asphaltene carboniferous fuel before or during combustion.

In another embodiment of the present invention there is provided an additive high asphaltene carboniferous fuel comprising a high asphaltene carboniferous fuel and a fuel additive as described above.

In yet another embodiment of the invention, a method for preparing a fuel additive comprises mixing a plant extract with an oil-soluble carrier and one or more of an organometallic material, an oxygen carrier, a stability aid, a lubrication aid, and an antioxidant, and a combustion enhancer. In another embodiment of the invention, the fuel additive is prepared in an oxygen or reduced oxygen free atmosphere, and optionally may include the step of excluding UV radiation sources during preparation. In yet another embodiment, oil-soluble non-oxidized vehicles and non-oxidized oxygen vehicles are used.

Plant extract used in various embodiments of the invention can be obtained by solvent extraction from whole plants using hydrocarbon soluble solvents.

Polar or nonpolar hydrocarbon soluble solvents may be used for extraction. The resulting extract from the extraction process is a crude material containing over 300 individual compounds. In one mode. The extract has a paste or sludge-like consistency that can be described as a solid or semi-solid than as a liquid. These extracts typically contain chlorophyll a and chlorophyll B with a higher concentration of chlorophyll A over chlorophyll Β. The color of such extracts is usually a deep black green with some degree of fluorescence. Such an extract can be recovered from most plants although green plants even those with darker leaves tend to have higher concentrations. Extracts from plants of the Leguminosae family are suitable. While such a solid or semi-solid form is generally considered to be preferred for most styles, in other embodiments, a liquid form or other form may be suitable, and may still be preferably. In addition, carotenoid, chlorophyll or xanthophyll synthetic materials may be used in place of or in addition to natural plant extracts.

The foregoing has somewhat broadly outlined the features and advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Further features and advantages of the invention will be described hereinafter in this patent application which form the subject of the claims of the invention. It will be appreciated that it will be appreciated by the person skilled in the art that the design and specific embodiments described may be readily used as a basis for modifying or designing other structures for the purposes of the same purposes as the present invention. It should also be noted by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as shown in the appended claims. The novel features believed to be characteristic of the invention, as well as its organization and method of operation, together or other objectives and advantages, will be better understood from the following description when considered in connection with the inventions. accompanying figures. It is to be expressly understood, however, that each of the figures is provided for illustration and description purposes only and is not intended as a definition of the limits of the present invention.

BRIEF DESCRIPTION OF DRAWINGS

For a more complete understanding of the present invention, reference is made hereinafter to the following descriptions taken in conjunction with the accompanying drawings, in which:

Figure 1 is a graph of NOx emissions measured at the furnace outlet relative to the various fuel additives used in the EERC test;

Figure 2 is a graph of the NOx emissions measured in the basement with respect to various fuel additives used in the EERC test;

Figure 3 is a graph of dust emission loads with respect to the EERC test;

Figure 4 is a graph of flow and heat divided by fuel ignition rate versus excess air for the EERC test; and

Figure 5 is a graph of the temperature feed rate for the EERC Test.

DETAILED DESCRIPTION

As used in this descriptive report, the term "β-carotene mixture" is defined as a mixture from about 89 to about 98% trans β-carotene with the remainder being from about 2 to about 11% of the various useful isomers of beta carotene or other conjugated poly unsaturated hydrocarbons.

An example of such a beta carotene blend is ISOMIXTENE®, a product marketed by DSM Nutritional Products, Inc. of Parsippany, New Jersey.

Embodiments of the present invention are directed to systems, methods and compositions that improve the combustion characteristics of high asphaltene coal fuels. Examples of combustion characteristics that can be improved include increased combustion efficiency and reduced emissions of one or more pollutants, such as ozone, particulate matter (PM), carbon monoxide, nitrogen oxides (NO2). sulfur dioxide, poly nuclear aromatic compounds, and soluble organic fractions.

In one embodiment, a fuel additive comprises a plant extract. Suitable extracts and plant include extracts from green leafy plant material. Specificly useful plant extracts are extracts from plants of the Leguminosae family, which may include fescue extract, alpeque extract, and alfalfa extract. The plant extract may be provided in such an amount that the high asphaltene carboniferous fuel to be treated includes a concentration of plant extract by weight in the range of about 0.5 ppm to about 10,000 ppm of preferably from about 200 ppm to about 2000 ppm, and more preferably about 800 ppm. Without being bound by theory, it is believed that the oxygen-pooling properties of such plant extracts provide advantageous improvements to the combustion of high asphaltene carbonaceous fuels such as residual fuel oil and coal.

Plant extracts can be obtained using well-known extraction methods from those skilled in the art. Solvent extraction methods using hydrocarbon soluble polar or non-polar solvents are generally preferred. Any suitable extraction solvent that is capable of separating suitable fractions from the plant material may be used. Suitable non-polar solvents include straight chain or branched chain alkanes containing from about 5 or less to 12 or more carbon atoms. Specific examples of acyclic alkane solvents include pentane, hexane, heptane, octane, nonane, decane, mixed hexanes, mixed heptanes, mixed octanes, isooctane and the like. Examples of cycloalkane solvents include cyclopentane, cyclohexane, cycloheptane, cyclooctane, methylcyclohexane, and the like. Alkenes such as hexenes, heptenes, octenes, nonenes and decenes are also suitable for use as are aromatic hydrocarbons such as benzene, toluene and xylene. Halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorobenzene, methylene chloride, chloroform, carbon tetrachloride, perchlorethylene, trichlorethylene, trichlorethane and trichlorofluoroethane may also be used. In general, the solvents are preferably polar. are the Ce to C12 alkanes, specifically n-hexane.

Suitable polar solvents may include, but are not limited to, acetone, methyl ethyl ketone, other ketones, methanol, ethanol, other alcohols, tetrahydrofuran, methylene chloride, chloroform, or any other suitable polar solvent.

Hexane extraction is a commonly used technique for extracting plant oil material. It is a highly efficient extraction method that extracts virtually all oil-soluble fractions from plant material. In a typical hexane extraction, the plant material is ground. Grass and leafy plants can be shredded into small pieces while seeds are typically ground or flaked. Plant material can be pelletized to 2.540 or 1.905 centimeters (1/1 or 3/4 inch). Plant material is typically exposed to hexane at an elevated temperature. Hexane, a highly flammable, colorless and volatile solvent that dissolves oil, typically leaves only a small percentage by weight of oil in the residual plant material. The oil and solvent mixture may be heated to about or above 100 ° C to remove most of the hexane, and may then be distilled to remove all traces of hexane. Alternatively, hexane may be removed by evaporation under reduced pressure. The resulting plant extract is suitable for use in the production of the fuel additives of the present invention.

Other extraction processes include supercritical fluid extraction, typically with carbon dioxide, so other gases such as helium, argon, xenon and nitrogen can also be used as solvents in supercritical fluid extraction methods.

Yet another useful extraction process is mechanical pressing, also known as expelling pressing, which removes oil through the use of continuously driven screws that crush the seed or other oil-containing material into a pulp from which the oil is extracted. Oil is squeezed. The friction created by the process may generate temperatures between about 50 ° C and 90 ° C, or external heat may be supplied. Cold pressing generally refers to mechanical pressing performed at a temperature of 40 ° C or less without external heat and application. The yield of extracted oil that can be obtained from a plant material depends on a number of factors, but primarily on the oil content of the plant material. For example, a typical vet oil content (hexane extraction, dry base) is approximately 4 to 5 wt%, while for barley it is approximately 6 to 7.5 wt% to that of alfalfa. approximately 2 to 4% by weight.

Plant oil extracts for use in edible or cosmetic items are typically subjected to additional processing steps to remove impurities that may affect appearance, shelf life, taste and the like to produce a more refined product. . Impurities may include phospholipids, mucilagenous gums, free fatty acids, colored pigments, and fine plant particles. Different methods are used to remove these by-products, including precipitation in water or precipitation in aqueous solutions of organic acids. Colored compounds are typically removed by bleaching in which oil is typically passed through an absorbent such as diatom clay. Deodorization may also be performed, which typically involves the use of steam distillation. Although extracts used as fuel additives in the present invention may include these additional processing steps, these additional steps are not generally required.

The fuel additive may optionally include an organometallic compound. Suitable organometallic compounds are hydrocarbon-soluble organometallic compounds that include metals selected from the first and second tiers of transition metals, suitable organometallic compounds include pentacarbonyl, iron naphthene, ferrocene and combinations thereof. The inclusion of organometallic compound is believed to be specifically useful in improving the combustion characteristics of specifically high asphaltene fuels such as residual fuel oils and coal in areas other than the world. North America. The organometallic compound may be provided in such an amount that the fuel to be treated includes a weight concentration of organometallic compound in the range of about 0.5 ppm to about 10,000 ppm as metal, preferably from about 200 ppm. up to about 2000 ppm as the metal, and more preferably about 800 ppm as the metal. Without being bound by theory, it is believed that the inclusion of an organometallic compound provides a catalytic effect to reactions promoted through the plant extract material.

The fuel additive may further comprise meadowfoam oil. Meadowfoam oil has a number of useful properties and can function as an oxygen carrier, a stability aid and an antioxidant. Because plant extracts used in the fuel additives of the present invention have oxygen assembling properties, and therefore may be unstable, the inclusion of a material such as meadowfoam oil may assist in maintaining the stability of the extracts of plant and prevent their oxidation.

The composition may optionally further include at least one carotene which may be provided as a β-carotene mixture such as ISOMIXTEN®. While carotenoids such as the mixtures described above, other molecules having extended pi or double bond structures of from about 2 to 11 or more conjugated double bonds are also considered to provide similarly improved combustion characteristics for the product. residues or other hydrocarbon fuels when used as additives for such fuels. Portions of such molecules that include the double bonding structures may be terminated by at least one end group which. also comprises an aromatic, cyclic, or branched portion of 5 to 8 carbon atoms that is saturated or unsaturated. Examples include cyclopentane, cyclopentene, cyclohexane, cyclohexene, cycloheptane, isopentane or isopentene. Aromatic structures are also considered as prolonged pi structures. The unsaturated / aromatic moieties and the final groups may additionally include various other substituents such as hydroxyl groups, keto groups, alkyl groups, alkenyl groups and the combinations. In addition, the additive molecules may comprise from 12 to 40 or 50 carbon atoms. These molecules are found in mixtures of synthetic carotene precursors. These additives may be obtained from natural or synthetic sources.

In addition, lycopene is another example of a suitable carotene. Other suitable carotenoids and carotene precursors are described in German Patent 954,245, issued in 1956 and incorporated herein by reference by reference.

If the fuel additive comprises a carotene, it may also comprise an antioxidant. Suitable antioxidants include alkyl phenols, such as 2-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butylphenol, 2-tert-butyl-4-n-butylphenol, 2,4,6-tri-tert-butylphenol, 2,6-di-tert-butyl-4-n-butylphenol, and mixtures thereof. These antioxidants are suitable for use as stabilizers for half distillation fuels. Other antioxidants include delayed phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol; 2,6-di-t-butylphenol; 2,2'-methylene bis (6-t-butyl-4-methylphenol); n-octadecyl propionate 3- (3,5-di-t-butyl-4-hydroxyphenyl); 1,1,3-tris (3-t-butyl-6-methyl-4-hydroxyphenyl) butane; pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]; di-n-octadecyl (3,5-di-t-butyM-hydroxybenzyl) phosphonate; 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) mesitylene; tris (3,5-di-t-butyl-4-hydroxybenzyl), pentaerythritol isocyanurate, esters derived from pentaerythritol, (3-alkyl-4-hydroxyphenyl) alkanoic acids and alkyl thioalkanoic acids or lower alkyl esters of such acids and combinations thereof. These stabilizers are used with organic material normally susceptible to oxidation and / or thermal deterioration. Also useful are the reaction product of malonic acid, dodecyl and tallow aldehyde, retarded phenyl phosphates, delayed carboxylic acid piperidines and metal salts thereof; deferred derivatives of 2,6-dihydroxy-9-azabicyclo [3.3.1] nonane; retarded bicyclic amines, sulfur-containing dialkyl-4-hydroxyphenyl triazine derivatives, retarded bicyclic amino acids and their metal salts, trialkyl substituted hydroxybenzyl malonates, retarded carboxylic acid piperidines and their metal salts, acids and dicarboxylic pyrrolidine esters, β, β-disubstituted beta alamine metal salts, thioalkylene hydrocarbyl phosphates, thioalkylene hydroxybenzyl phosphates the like.

Specific antioxidants useful in the present invention are quinoline or dehydro quinoline compounds such as 1,2-dihydroquinoline compounds. More specifically 6-ethoxy-1,2-dihydro-2,2,4-trimethyl quinoline commonly referred to as ethoxyquin may be used as antioxidants. Ethoxyquin is marketed under the trademark SANTOQUIN® by Novus International Inc. of St. Louis, Missouri, and is widely used as an antioxidant for animal feed and fodder.

The fuel additives of the present invention may also contain a combustion enhancer such as a ketone improver or ignition accelerator. Suitable combustion enhancers are organic nitrate materials. Preferably organic nitrates are substituted or unsubstituted alkyl or cycloalkyl nitrates having up to about 10 carbon atoms and preferably from 2 to 10 carbon atoms. . The alkyl group can be either linear or branched. Specific examples of suitable nitrate compounds include methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl nitrate, alkyl nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, nitrate tert-butyl acid, n-amyl nitrate, isoalyl nitrate, n-hexyl nitrate, 2-ethylhexyl nitrate, n-heptyl nitrate, sec-heptyl nitrate, n-octyl nitrate, sec-octyl nitrate , n-nonyl nitrate, n-decyl nitrate, n-dodecyl nitrate, cyclopentyl nitrate, cyclohexyl nitrate, methylcyclohexyl nitrate, isopropylcyclohexyl nitrate, and alkoxy substituted aliphatic alcohol esters, such as 1-methoxypropyl-2-nitrate, 1-ethoxypropyl-2 nitrate, 1-isopropoxy-butyl nitrate, 1-ethoxybutyl nitrate, and the like. Preferred alkyl nitrates are ethyl nitrate, propyl nitrate, amyl nitrates, and hexyl nitrates. Other alkyl nitrates preferably are mixtures of primary amyl nitrates or primary hexyl nitrates. By "primer" is meant that the functional group of nitrate is attached to a CH2 group of the amyl or hexyl group. Examples of primary hexyl nitrates include n-hexyl nitrate, 2-ethylhexyl nitrate, 4-methyl-n-pentyl nitrate, and the like. Preparation of nitrate esters may be accomplished by any of the commonly used methods, such as by esterification of the appropriate alcohol or reaction of a suitable alkyl halide with silver nitrate. Such additives may be present in the same or different quantities as the other components of the fuel additive.

Fuel additives may further include a diluent or solvent carrier. Such a vehicle is useful because, in general, low concentrations of the specific fuel additive components are effective in achieving the desired results, and therefore the use of a vehicle simplifies the addition of the fuel additive. Using a vehicle can also help keep components in solution, and can also help prevent component oxidation.

Suitable solvents for use in the vehicle include one or more aromatic hydrocarbons such as toluene or xylene, or other hydrocarbons such as gasoline, jet fuel, or diesel fuel. In one embodiment, a mixed aromatic solvent comprising various xylene isomers is used. Examples of such solvents include those commercially available in North America from Exxon Mobil Chemical and marketed under the names AROMATIC 100 FLUID and AROMATIC 150 FLUID. In one embodiment, a mixture of AROMATIC 100 FLUID and AROMATIC 150 FLUID is used.

When combining specific fuel additive components, the preparation of the fuel additive in an oxygen-free or low oxygen atmosphere may be useful to prevent oxidation of the fuel additive components. Optionally, components may be combined under conditions in which sources of UV radiation are excluded to also prevent component degradation. In those embodiments in which the fuel additive includes a plant extract such as fescue extract, alpeque extract, or alfalfa extract, meadowfoam oil and a carotene, the weight ratio of plant extract to carotene It may be from about 50: 1 to about 20: 1, and preferably it is from about 24: 1 to about 10: 1. The ratio of grams of plant extract to milliliter of meadowfoam oil can be from 12: 1 to about 20: 1, and preferably from about 6: 1 to about 10: 1. The ratio of milliliter of meadowfoam oil to carotene grams may be from about 12: 1 to about 20: 1, and preferably from 6: 1 to about 1: 1.

In those embodiments in which the fuel additive includes a carotene and an antioxidant, the ratio of carotene to antioxidant may be from about 20: 1 to about 1: 1, preferably from about 15: 1 to about 5: 1, and more preferably about 10: 1.

In another embodiment of the invention, wherein the fuel additive includes plant extracts and meadowfoam oil, the two may be provided in a weight ratio of from about 1: 100 to about 100: 1. In one embodiment of the invention, the concentration of plant extract in the total fuel additive composition may be from about 0.06 wt.% To about 6 wt.% And preferably from about 0 wt.%. 12 wt% to about 3 wt%. The meadowfoam oil concentration may range from about 0.05 wt% to about 5 wt% of the total fuel additive composition, and preferably is about 0.5 wt% of the total. of the fuel additive composition.

These fuel additives may be combined into high asphaltene carbonaceous fuels such that plant extract and organometallic material are present in the fuel at concentrations as shown above.

In embodiments in which the fuel additive includes a plant extract, an unoxidized carotene, an antioxidant, and meadowfoam oil, certain factors may be useful in determining appropriate component ratios. These factors may include the elevation at which the fuel will be combusted, the type of engine or device using the fuel, and the specific properties of the fuel. Examples of different engine types or devices include two-cycle diesel engines and stationary boilers. Examples of relevant fuel properties include sulfur content, mercaptan content, olefin content, aromatics content and asphaltene content. For example, if a fuel has a high sulfur content of 1 wt% or more, or a high aromatic content of 25 wt% or more, the proportions may be adjusted to provide an additional plant extract or an additional unoxidized carotene.

According to another embodiment of the invention there is provided an additive fuel in which a fuel additive such as the above is combined with a high asphaltene carboniferous fuel. Fuel compositions formulated according to the embodiments of the invention may further contain other known additives such as detergents, antioxidants, demulsifiers, corrosion inhibitors, metal deactivators, diluents, cold flow enhancers and thermal stabilizers.

According to another embodiment of the invention, a method for improving the combustion characteristics of a high asphaltene carboniferous fuel comprises the step of adding such an additive to a high asphaltene carboniferous fuel before or during combustion. .

The fuel additives of the present invention may be introduced into the waste fuel oil in a number of different ways. For example, the residual fuel oil to be combusted may be premixed to include the fuel additive. In another example, the fuel additive is injected into the residual fuel oil stream being fed to a burner or other combustion device. In this embodiment, the fuel additive can be injected using a metered injection system. This metered injection system can be optionally controlled via a computer system that can optimize the flow of any or all components to the combustion device to optimize its operation.

For coal, these fuel additives may be added similarly or in different ways. For example, the fuel additive may be sprayed onto coal prior to combustion. Alternatively, the fuel additive may be pumped or sprayed onto the charcoal burner together with charcoal using a metered injection system as described above.

EERC Lab Test

The test rounds were performed at the EERC Laboratory in Grand Forks, North Dakota. Six drums of residual fuel oil were used in the tests. The residual fuel oil was supplied by Sun Coast Resources in Houston, Texas. The properties of the waste fuel oil used are shown in Table 1. It had a moderate sulfur content of about 2.63% with a very high heating value of 44.5 MJ / kg at a moisture content of 2.40. %. Karl Fischer's water content was determined to be 0.21%. The volatile content of the sample was determined to be 89.30%, with the fixed carbon present at a level of 8.29%. The theoretical sulfur dioxide emission limit was determined to be 1714 ppm at a chimney gas oxygen concentration of 2.0%. This equates to an emission rate of 1.18 kg / MJ for sulfur dioxide (SO2). Residual fuel oil has a specific gravity of 0.9595, and the amount of sediment has been determined to be 0.05%. Table 1 also provides the next and last heating value analyzes for the residual fuel oil tested along with the theoretical sulfur emission limit. Table 1. Residual fuel oil analyzes when burned (ASTM standard analyzes *)

<table> table see original document page 19 </column> </row> <table>

* American Society for Testing and Materials

The residual fuel oil was stored cold before the test.

Barrel heaters were used to heat the residual fuel oil to 121 sC before transferring it to the feed container above the pump. A barrel heater was attached to the feed container tank to keep the residual fuel oil warm during the test, measuring between 113 ° C and 118 ° C for use during the test periods shown here in the table. Although the oil appears to be somewhat viscous at this temperature, a homogeneous phase was maintained such that an easily controlled feed rate for the combustor was achieved during all test periods.

Test equipment at EERC facilities includes a furnace with a capacity of approximately 19 kg / hour (845 MJ / hour) of residual fuel oil. The combustion chamber is 0.06 meters in diameter, 2.44 meters high and lined with refractory material for combustion testing of various types of oil. The diameter of the oven can be reduced to 0.66 meters for the rising temperature that is entering the convective passage. Furnace outlet temperatures (FEGTs) as high as 1400eC were achieved during the combustion test in this mode. However, most tests were performed using the standard configuration (0.76 meter ID) with FEGT maintained between 1100 ° C and 1200 ° C, although FEGT is typically raised to 1250 ° C. and 1300 ° C for combustion of residual fuel oil. Two S-type thermal pairs located on top of the combustion chamber are used for FEGT monitoring. They are situated 180s apart at the midpoint of the transition from vertical to horizontal flow. Air level excesses are controlled manually by adjusting valves in the primary and secondary air currents. Typical distribution is 15% in primary and 85% in secondary to achieve a typical air level excess of 20%.

At the time of combustion of fuels such as residual fuel oil, a pump is used to transport the fuel through a dual fuel atomizer into the combustion chamber. Air or steam is commonly used as the atomizing fluid. The combustion air is preheated by an electric air heater. The heated secondary air is introduced through a whirlpool burner. Chimney gases pass out of the furnace into a 10-inch (25.4 cm) square duct that is also lined with refractory material. A vertical probe bank located in the duct is designed to simulate overheated surfaces in a commercial boiler. After leaving the probe duct, the chimney gas passes through a series of water-cooled heat exchangers lined with refractory material and a series of air-cooled heat exchangers before being discharged through or an electrostatic precipitator (ESP) or a "baghouse" (BH) for particulate removal.

At EERC installations, flame stability is assessed by observing the flame and generating it with the burner "quarl" as a function of a secondary air whirlpool and operating conditions at full load and under operating conditions. shutdown. An International Flame Resume Foundation- type secondary air swirl generator (IFRF uses primary and secondary air for approximately 15% and 85% of total air, respectively, to adjust the swirl between 0 and 1 The swirl is defined as the ratio of radial (tangential) momentum to axial momentum imparted to secondary air through movable blocks within the burner and is used to adjust an internal recirculation zone ( IRZ) inside the flame that allows for a greater mixing of the combustion air and the fuel.The small end is checked by moving the blocks to fix alternate radial flow and tangential flow routes to create a rotation on the Secondary airflow which increases turbulence in the area near the burner.

In the fully open position of the rotary block, secondary air passes through the rotary burner and the momentum of this current has only one axial component such that air enters the combustion layer like a jet. As the angle of the block changes, air begins to spin or "swirl" and the radial momentum component is established, creating the IRZ in the region near the burner. It is the ratio of this radial component of momentum to the axial component that establishes the amount defined as the whirlpool.

The adjustable swirl burner used by EERC during flame stability tests consists of two annular planes and two series of interlocking wedge-shaped blocks, each attached to one of the plates. The two sets of blocks can form radial and tangential alternating flow channels such that the air flow is divided into an equal number of radial and tangential currents that combine further downstream into a swirling flow. By simply rotating the movable plate, the radial channels are progressively closed and the tangential channels are opened such that the resulting angular momentum flow continuously increases between zero and a maximum value. This maximum swirl adjustment depends on the total airflow velocity and swirl generator geometry. The whirlpool can be calculated from the dimensions of the movable blocks (the proportion of the tangential and radial openings of the blocks) or from the measurement of airstream velocity (obtaining both radial and axial components).

Secondary air swirl is used for flame stabilization. In the absence of the whirlpool, flame loss may result, increasing the risk of a double explosion. As the whirlpool is applied to the combustion air, the fuel droplets are drawn into the IRZ1 increasing the particle heating rate and leading to an increase in the release of volatiles and combustion ash. The flame becomes more compact and intense as the whirlpool is raised to an optimum level, which is characterized in EERC test facilities as the point at which the flame contacts the burner quarl. Increasing the whirlpool beyond this level can push the flame into the burner region, unnecessarily exposing the burner metal components to the intense heat of the flame and possible combustion in the coal pipe. The adjustments to the swirl adjustment were made manually by moving a lever attached to the movable block assembly. The position of the blocks was observed on a linear scale.

Increasing the whirlpool to provide flame stability and an increase in carbon conversion can also affect NOx formation. High flame temperatures and the increased fuel and air mixture associated with the whirlpool create an ideal situation. under which NOx can form. In full-cut burners with adjustable fans, the whirlpool is almost always increased to the optimum condition for carbon conversion, and then slightly reduced to reduce NOx production.

The general test method at EERC installations sets the burner to its maximum swirl level and monitors system parameters such as fuel feed speed, excess air, gaseous emissions such as O2, CO2, CO, SO2, and NOx, combustor statics and air flow rates. Flame and burner zone photographs were taken through an inspection opening in the oven just above the burner cone using standard 35 mm film. Flame temperature was also measured using a high speed thermal pair (HVT) at a fixed oven location, and heat flow was monitored using a luxury baseline heat probe on it. location. An ash sample was collected at each swirl adjustment to establish carbon burn. The swirl adjustment was then reduced until the flame was visually observed by raising the burner quarl. At this point, the flame was characterized as unstable under full load conditions which are a combustion rate of between 633 and 686 ML / per hour. Photographs were taken again to record the flame at this setting, temperature and heat flow measurements were taken, and a gray sample was taken again. Once the flame lift was established, the optimum swirl adjustment was located by visual observation of the flame and measurements were recorded once again.

Flame stability under dimming conditions is characterized by combustion of the test fuel at a reduced load, typically half or three quarters of the full charge rate, maintaining the same primary air flow by adjusting the secondary air flow. to satisfy excess air needs. The procedure described above was used for the establishment of reduced load flame stability.

CTF utilizes two sets of Rosermount gas analyzers for monitoring O2, CO, CO2, and NOx. Sulfur dioxide (SO2) is monitored through analyzers manufactured by Ametek. The analyzers were typically located at the furnace outlet and at the particulate material control device outlet.

Gas analyzes are recorded on a dry basis. Balcon Environamental manufactures the chimney gas conditioners used to remove water vapor from each gas sample. Chimney gas constituents are constantly monitored and recorded by the CTF data acquisition system.

One of the probes used to characterize the shape and intensity of the flame is the heat flux baseline probe. The probe uses water to collect heat from a 2.5 cm thick stainless steel tipped instrument that is inserted into an opening in the sidewall of the radiation zone such that the surface of the it is even parallel to the inner wall of the combustion chamber. Water flow rate is measured by turbine flow meters and water temperature is measured by Type K thermal pairs at the inlet and outlet of water streams. Two thermal pairs embedded in the outer and inner surfaces of the probe monitor the metal temperatures. From these values the heat flux is calculated.

In addition to the heat flow baseline probe, an HVT was used to measure the true gas temperature at the same location. The probe is water cooled to protect the stainless steel outer shell from the intense heat of the combustion flame. An S-type thermocouple runs below its center and is protected from the radiation of the flame and refractory walls by a point made from an insulating plate. A vacuum pump is used to pull gases through the thermal pair junction at a rate sufficient to reach a speed after the thermal pair joins 120 m / sec. At this rate, the radiation component for heat transfer is minimized and convective heat transfer is dominant. In this way, the true gas temperature can be obtained without radiation interference or from the junction of the thermal pair.

Ash samples were obtained from various devices at the entrance or exit of the ESP or BH pilot plant. The U.S. Environmental Protection Agency (EPA) Method 5 was used to establish particulate matter (PM) concentrations in the flue gas. High-volume sample extraction and filling funnels from the pilot plant control collection device can provide large samples for study. Residual fuel oil samples were heated to lower fuel viscosity prior to atomization in the burner.

Fuel additives were added to the heated fuel stream near the atomization nozzle by means of a specially designed metered injection system. In the injection system a fuel flow meter was used to determine the fuel flow, the outlet was fed into a PID controller which then controlled the flow rate of a chemical introduction pump. The fuel additive concentration has been dynamically adjusted for any change in fuel flow rate. The material exiting the delivery pump was injected into the flowing heated fuel producing a droplet dispersion of the fuel additive in the fuel. This mixture then passed through a static mixing section which ensured that the treated fuel was homogeneously mixed with the fuel before entering the atomizer section of the burner.

The tests were performed for three days at EERC facilities with an oven gas outlet temperature (FEGT) of between 1250 ° C and 1325 ° C and at or near 10% excess air level. This corresponds to approximately 2.9% oxygen in the chimney gas at the furnace outlet. The residual fuel oil combustion rate and airflow combustion rates were adjusted during each of these tests to maintain these levels. On the fourth day, each test was performed at an FEGT between 1250 ° C and 1325 ° C and an excess air level of or near 5%. Tables 2 through 7 provide baseline and round average summaries of operating conditions for each of the test periods during each test day. Control of the residual fuel oil feed rate was achieved by adjusting the same fixed point on the pump speed controller. The controller then adjusted the pump speed to keep the feed rate at the desired level.

Excess air levels were achieved by manually adjusting valve positions on each of the primary and secondary air currents. A BH was used for particulate material control during all test periods.

The oven was preheated to 1290 ° C with natural gas for up to 8 hours before the start of each test day. The furnace pressure was maintained close to -1 torr by adjusting a control valve that combined ambient air into the duct at the inlet of the induced suction fan.

Two sets of analyzers monitored the gaseous emissions and were designated as furnace outlet and BH outlet in each of Tables 2 through 6. The furnace outlet analyzes were sampled approximately 1 meter downstream of the probe bank. clogging. This oxygen level was used to control excess air levels during each test. BH output analyzes were normally obtained from the duct structure following the BH. Due to the higher vacuum at the rear end of the test system and the large number of flange connections, air leakage to the inside of the duct structure resulted in a 1 to 2% increase in gas concentrations of the chimney. Oxygen analysis from each set of analyzers was used to correct the gaseous emissions of interest for a constant airflow level of 20% (3.5% O2). The calculation used to correct the emission levels reported here is:

<formula> formula see original document page 26 </formula>

The gas analyzers were zeroed and extended before each test. Additional analyzer calibration was performed when results were suspect or unexpected.

In the AF-CTS-751, 753, 755, 756-1, and 758 (twice) tests, the primary objective was to establish baseline operating characteristics, emission rates for the various gas species, and work. produced under various operating conditions. In addition, ash samples were collected to determine the dust load (or PM) of the gas stream entering the BH. The results of these tests are provided in Tables 2 through 6. Since stable combustion conditions were achieved after switching from natural gas to residual fuel oil, a series of measurements were made using an HVT, a probe. heat flux baseline and a small cyclone to obtain the suspended ash. The swirl adjustment in the secondary airflow was kept constant at 3.5 throughout the test periods performed during this series of tests.

In all other tests, the primary objective was to establish the effectiveness of the various fuel additives for lowering gaseous emissions and increasing the operating procedure. The same test protocol was used here to determine the effectiveness of fuel additives. Results from these tests are given in Tables 2 through 7. As part of the test protocol, a period of operation at baseline typically preceded all test periods during which a fuel additive was evaluated.

The following are the fuel additive formulations used in this study:

Additive 2: 5 ml meadowfoam oil (d = 0.91 g / ml); 5.1 g fescue extract (extracted with hexane); and 995 ml AROMATICS 150 FLUID (d = 0.90 g / ml); not prepared in a glove box;

Additive 5: 5 ml meadowfoam oil (d = 0.91 g / ml); 5.2 g alfeque extract (extracted with hexane); 2 ml 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline (d = 1.03); 1.6 g ISOMIXTENE®; and 993 ml AROMATIC 100 FLUID (d = 0.87 g / ml); prepared in a glove box under non-oxygenation conditions;

Additive 6: 80% (v / v) of Component 1 and 20% (v / v) of Component 2 wherein: Component 1: 5 ml meadowfoam oil (d = 0.91 g / ml); 5.1 g of alfeque extract (extracted with hexane); and 995 ml AROMATICS 150 FLUID (d = 0.90 g / ml); not prepared in a glove box;

Component 2: 2-ethylhexyl nitrate.

Additive 7: 80% (v / v) Additive 5 and 20% (v / v) 2-ethylhexyl nitrate, Additive 8: 0.5 ml 2,2,4-trimethyl-6-ethoxy-1, 2-dihydroquinoline (d = 1.03); 0.8 g ISOMIXTENE®; 2.5 ml meadowfoam oil (d = 0.91); 0.39 g of fescue extract (extracted with hexane); and 500 ml AROMATIC 100 FLUID (d = 0.87); prepared in a glove box under non-oxygenation conditions,

Additive 9: 0.5 ml 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline (d = 1.03); 0.8 g ISOMIXTENE®; 2.5 ml meadowfoam oil (d = 0.91); 0.39 g of alpine extract (extracted with ethanol); and 500 ml AROMATIC 100 FLUID (d = 0.87); prepared in a glove box under non-oxygenation conditions,

Additive 10: 0.5 ml 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline (d = 1.03); 0.8 g ISOMIXTENE®; 2.5 ml meadowfoam oil (d = 0.91); 0.39 g of alpine extract (extracted with hexane); and 500 ml AROMATIC 100 FLUID (d = 0.87); prepared in a glove box under non-oxygenation conditions.

The following tables give the test results for residual fuel oils and related fuel additives. Table 2. Test Round AF Baseline and Operating Parameters AF-CTS-745

<table> table see original document page 29 </column> </row> <table> <table> table see original document page 30 </column> </row> <table> <table> table see original document page 31 < / column> </row> <table> Table 3

<table> table see original document page 32 </column> </row> <table> Table 4. Test Round Baseline and Average Operating Parameters - AF-CTS-753 (cont.) & 754

<table> table see original document page 33 </column> </row> <table> Table 5. Test Round Baseline and Average Operating Parameters - AF-CTS-755

<table> table see original document page 34 </column> </row> <table> Table 6. Test Round Baseline and Average Operating Parameters - AF-CTS-756 & 757

<table> table see original document page 35 </column> </row> <table> Table 7. Test Round Baseline and Average Operating Parameters - AF-CTS-758

<table> table see original document page 36 </column> </row> <table> The initial experimental test began the day before the actual test and included the burning of the residual fuel oil to establish the effectiveness of the changes that the first series of earlier fuel additive tests had been made for the system.

This trial period found that the changes made improved the overall operating capacity of the system. Included among many changes were the addition of insulation to various system feed lines, the water vapor piping to the burner gun to be used as the atomizing fluid for the oil, the addition of a mixing section in the fuel line, and the addition of water vapor heaters in the storage barrel that was used to fill the feed tank to maintain a residual fuel oil temperature at or near 115.5 ° C. (240 ° F). The result of the changes allowed the fuel to be continuously fed through the burner gun without the formation of carbon deposits in the gun or the air piping inside the burner quarl.

FEGT was maintained close to 1,287.79 ° C (2350 ° F) during all periods. In some cases it was allowed to increase to observe the effect of the fuel additive on the operation produced, and in other cases it was maintained. during injection of the fuel additive to determine the level of fuel economy achieved while maintaining the same level of work produced. Because changes in fuel and operating parameters provided a very stable combustion environment, combustion effectiveness was very high during all test periods. This makes changes in the monitoring of the combustion environment that result from the addition of the fuel additive difficult. Changes in the combustion environment were, however, observed during this period and are detailed below. Due to the difficulty of monitoring changes, the excess air level was lowered to approximately 5% during the final day of the Day 4 tests.

Two sets of analyzers, one at the furnace outlet and one at the BH outlet, were used to determine the concentration of combustion products in the gas stream. The O2, CO, CO2, SO2, and NOx measurements in the flue gas were continuously monitored and recorded using the CTF data acquisition system. The averages of the test periods were provided in Tables 2 to 7.

Excess air levels fluctuated with changes in fuel feed rate and ranged from about 9% to 11% during testing from June 21 through June 23. Corrected SO2 emissions were relatively invariable at an average of approximately 1720 ppm ± 20 ppm during all test periods near 10% excess air.

An analysis of the data indicates that each of the analytical data that could be observed is a strong function of excess air. When an adjusted curved line is drawn across the data points, you can have a much better comparison view than if the data were adjusted overall. The oven and baghouse data are treated separately. Looking at the NOx and CO data (Figures 7 and 8, respectively), one finds that the results for one of the treated rounds are consistently lower than those for baseline measurements at an equal excess air. Additive 2 shows a consistent improvement in gas emissions. Surprisingly, this fuel additive shows its effect, even though it was used only in experiments with about 10% excess air.

Measured particulate matter (PM) emission values and expressed as dust loads were obtained at BH input during a number of test periods using the U.S. Environmental Protection Agency Method 5 PM sampling. These tests provided significant evidence of the effectiveness of various fuel additives in improving the combustion characteristics of residual fuel oil (see Figure 9). During the baseline test on Day 4 (Test Period 12) , dust loads entering BH were determined to be 0.122 g / m3. During Test Period 5, Additive 5 was injected at a rate of 30 ml per hour when Method 5 EPA dust loading was significantly reduced to 0.0677 g / m3, a reduction of 44.6 %. In Test Period 13, Additive 8 was used at an addition rate of 40 ml / hour as was Additive 10 in Test Period 16. Method 5 EPA dust loading was reduced while using Additive 8 to 0 08866 g / m3 and to 0.0959 g / m3 while using Additive 10. This translates into a 27.5% reduction and a 21.5% reduction respectively. It should be noted that excess air levels during Test Period 5 (Additive 5) were higher than those with respect to Test Period 12, the baseline test period, thus a part of the reduction noted. This can be taken into account regarding the increase in available oxygen. However, this was not the case with respect to Test Periods 13 (Additive 8) and 16 (Additive 10). Excess air levels were approximately the same during the baseline test period as they were during the two observed test periods.

Although heat flow behavior is a complicated function, it is presumed to be a function of at least the fuel burn rate and excess air. Figure 10 plots heat flow as measured in the EERC divided by the fuel burn rate versus the excess air recorded. The data show that the ratio of heat / fuel flow produced to fuel treated with Additive 2 was higher than that observed with respect to Additive 2.

An infrared (IR) camera / recorder was used to assess any changes in flame temperature that could occur between baseline and fuel additive injection periods. The results from these measurements were summarized in Table 8. It could appear from the data below that the most telling trend in flame temperature was the fuel feed rate. This relationship can be seen in Figure 6. The equation of the linear regression line was provided and the value of R2 was calculated. The flame temperature does not fit well with a linear relationship with the feed rate, but does not tend in that direction. Although the test furnace was operated at a similar furnace gas outlet temperature during each operating day, the corresponding flame temperature varied significantly from day to day, as does the required feed rate to achieve that. temperature. This indicates that the heat flow through the furnace walls tends to change from day to day. However, within a single day operation, only small trends could be observed.

During the first day of testing, the flame temperature recorded immediately before the fuel additive injection and immediately after the injection of Additive 2 remained constant at 1333 ° C. The feed rate was also constant. However, during the second test day, the baseline feed rate (Test Period 4) was considerably higher during fuel additive injection. Flame temperature readings from the IR camera were constant at 1402 ° C during Test Periods 5 and 7 with Additive 5 injection at a rate of 30 ml per hour and 14 ml per hour, respectively. This could indicate some effect of the fuel additive on heat release in the oven. During Test Period 8, Additive 6 was injected at a rate of 40 ml per hour. Although the flame temperature dropped to 1392SC, the feed rate was significantly reduced from baseline levels during this period to 16.23 kg / hour. Table 8. Summary of Data Recorded by Camera IR.

<table> table see original document page 41 </column> </row> <table> The flame temperature at the 1366 ° C baseline was reached in Test Period 9 with a feed rate of 17.19 kg per hour of residual fuel oil. After injection of Additive 7 at a rate of 40 ml per hour, the flame temperature remained constant at a lower feed rate of 16.50 kg per hour. This represents a reduction in feed of approximately 4%. During the final day of the test, the initial baseline flame temperature was recorded at 1371 ° C (Test Period 12). Although the temperature dropped to 1359 ° C during the injection of Additives 8 and 9, it remained relatively constant throughout the day, rising to 1362 ° C during the next Baseline Test Period 15. . Essentially no change occurred during Test Period 16 when Additive 10 was injected at a rate of 40 ml per hour. The flame temperature remained constant at 1360 ° C.

CANMET Oven Search Test

A test was also performed at CANMET Research Furnace in Ottawa, Canada. The waste fuel oil used was obtained from PROVAM Fuels Inc. of Hamilton, Ontario. The properties of the residual fuel oil are listed in Table 9. This residual fuel oil had a moderate sulfur content of about 1.7% with a very high heating value of 42.12 MJ / kg at a high sulfur content. moisture content of 0.05%. The analyzes of near, last and heating values with respect to the residual fuel oil tested are also provided in Table 1 together with the theoretical sulfur emission limit. Table 9

<table> table see original document page 43 </column> </row> <table> Residual fuel oil was stored cold before testing. A Dia tank was used to heat the residual fuel oil to 121 ° C and to keep the oil warm during the test.

In this test protocol the furnace control was primarily based on the flow of fuel into the furnace. The fuel flow was kept constant along with the air flow. A calorimetric section of the furnace allowed heat transfer from the furnace to be performed as a function of distance from the burner. There was no baggage in this system and the oven outlet temperature was allowed to fluctuate.

When a liquid fuel such as residual fuel oil is combusted, a pump is used to transport the fuel through the dual fluid atomizer into the combustion chamber. In this furnace, compressed air is used for atomization of the fuel. Air for combustion is preheated by an electric air heater.

Flame stability is assessed by observing the flame through a quartz observation aperture located along the longitudinal axis of the furnace at the furnace end end opposite the burner. Under normal operation, a camcorder was used to quantitatively assess flame quality and to create a video record of the flame characteristics that occurred during the experiment.

The general test method places the burner at its maximum swirl level and monitors system parameters such as fuel feed rate, excess air, gaseous emissions (O2, CO2, CO, SO2, and NOx). ), combustor static and air flow rates. Photographs of the flame and the burner zone were taken through an observation aperture in the oven just above the burner cone using a camcorder.

The CANMET furnace uses two sets of gas analyzers for monitoring O2, CO, CO2, and NOx. Sulfur dioxide (SO2) is also monitored. Analyzers are typically located at the furnace outlet and particulate material control device outlet. Gas analyzes are recorded on a dry basis. Chimney gas constituents are monitored and recorded through the data acquisition system at 10-minute intervals during the experiment. Statistical characteristics of the measured quantities were used to establish the confidence limits of the measured data.

In the furnace calorimetric section, the inlet and outlet temperatures are monitored at 10 second intervals and recorded through the data acquisition system. Terminal operating fluid flow rates are also measured and accessible through the data acquisition system. From these measurements the furnace heat transfer can be determined as a function of time for each of the 28 calorimetric ranges along the longest axis of the furnace.

Ash samples were obtained by various means at the entrance or exit of the ESP or BH pilot plant. Isokinetic gas sampling is used to establish particulate matter (PM) concentrations in the chimney pipe gas. Large sample extraction and pilot plant control device collection feeders can provide large samples for study. The chemical composition was also determined with respect to the collected ash samples. The collection of isokinetic ash samples required approximately 3 hours per sample. Only one ash sample was collected per round.

The residual fuel oil was heated to lower its viscosity prior to atomization in the burner. Fuel additives have been added to the heated fuel stream near the atomizing nozzle by means of a specially designed metered injection system. In the injection system, a fuel flow meter was used to check the fuel flow, production was fed to a controller that controlled the flow rate of a chemical feed pump. Fuel additive concentration has been dynamically adjusted for any change in fuel flow rate. Feed pump production was injected into the hot edible that was flowing producing a dispersion of fuel additive droplets in the heated fuel. This mixture then passed through a static mixing section for homogeneous mixing of the fuel additive with the fuel that was entering the atomizer section of the burner.

The tests performed on the CANMET survey furnace were performed with the specified furnace operation using the fuel flow rate and excess air level, both of which were controlled by the furnace operator. The furnace was preheated with natural gas for up to 5 hours before the start of the residual fuel oil experiments. The standardized starting protocol involved collecting data with untreated fuel oil burning in the system for at least one hour before any experimental treatment began. This protocol allowed the baseline behavior to be verified on each day of operation. The experiments were designed to investigate the effects of chemical additives on furnace operation at two excess air concentrations (10% and 7.5%). Fuel baseline operation was determined at the beginning and end of the test campaigns as well as at the beginning of each test day.

In the test, all fuel additives were rated at a 10% excess air level. Fuel additive compositions for the CANMET test were prepared as follows with additives containing ISOMIXTENE® (Additives 13 and 14) prepared under inert atmosphere in a glove box, and additives in ISOMIXTENE® ( additives 11,12, 15 and 16) prepared under normal atmospheric conditions.

Additive 11 was prepared by mixing 13.9 grams of fescue extract and 10 ml meadowfoam oil, and then combining the mixture with AROMATIC 150 FLUID to up to 2000 ml.

Additive 12 was prepared by mixing 13 grams of fescue extract, 10 ml meadowfoam oil and 1 ml SANTOQUIN®, and combining the mixture with AROMATIC 150 FLUID to up to 2000 ml.

Additive 13 was prepared by mixing 5.12 grams of fescue extract, 5 ml meadowfoam oil, 10 drops of SANTOQIN®, and 0889 grams of ISOMIXTENE®, and combining the mixture with AROMATIC 150 FLUID to up to 1000 ml.

Additive 14 was prepared by mixing 5.13 grams of alfalfa extract, 5 ml of meadowfoam oil, 10 drops of SANTOQUIN®, and 088 grams of ISOMIXTENE®, and combining the mixture with AROMATIC 150 FLUID to up to 1000 ml. .

Additive 15 was prepared by mixing 13 grams of alfalfa extract, 10 ml meadowfoam oil, and 2 ml SANTOQUIN®, and combining the mixture with AROMATIC 150 FLUID to up to 2000 ml.

Additive 16 was prepared by mixing 13 grams of alfalfa extract and 10 ml meadowfoam oil, and combining the mixture with AROMATIC 150 FLUID to up to 2000 ml.

Table 10 summarizes the observations regarding particulate matter concentration in CANMET tests performed in a 10% air excess. The carbon content of the ash collected from the treated fuel experiments was uniformly lower than those observed in the reference system, but the total isotonic ash loading exhibited modest increases over Additives 11 and 12. In a proportion from lower excess air the carbon content of the collected ash was consistent with the isokinetic ash loading shown in Table 11.0 Additive 15 showed a consistent reduction in particulate material loading.

Table 10 CANMET Test: Particulate Matter Concentration at 10% Excess Air Level Test Round Isokinetic Ash Loading (mg / m3) Ash Carbon Content (% Carbon) Carbon Reduction (%)

<table> table see original document page 47 </column> </row> <table> Table 11. Results Dust loading at 7.5% excess air.

<table> table see original document page 48 </column> </row> <table>

Quantitatively, the flames of several of the treated fuels appeared shorter and brighter than the flames observed with reference (untreated) fuels. This observation is supported by the video of the flames, but is difficult to quantify. A shorter and denser flame should provide maximum heat transfer in the furnace calorimetric section. The data supporting this are found in Tables 12 and 13 with respect to experiments performed on both 10% and 7.5% excess air. Data were collected every 10 seconds to construct a large statistical sample. The standard deviation of this data set provides an uncertainty calculation. The heat uncertainty measured "therminol" is about 1%. The uncertainty regarding chimney gas heat is about 0.1%. Heat Disposition Changes above 2% are statistically significant at a confidence level of 95%.

Table 12. Heat Disposal from Heat Available at 10% Excess Air

<table> table see original document page 48 </column> </row> <table> Table 13. Heat Disposal from Energy Available at 7.5% excess air.

<table> table see original document page 49 </column> </row> <table>

IPT Lab Test

Tests were also performed at the IPT Testing Laboratory facilities, Sao Paulo, Brazil. The IPT test oven is operated similar to that of CANMET. The IPT test facility employs a horizontal burner, Model MPR manufactured by ATA Combustion Technical Brazil that is equipped with an outer jacket resined with water. Chimney gas fuel charge and excess air rates are taken as independent variables and other observable items are treated as dependent variables. The oven contains a calorimetric section. A significant difference in experiments conducted in Brazil is related to fuel. Brazilian fuel specifications are significantly different from those adopted in the United States. For example, the density and asphaltene content of commonly used waste fuels in Brazil is significantly higher than those commonly used in the United States. At these high levels of asphalt and viscosity, pollution caused by unburned carbon (particulate matter) of primary importance. Part of the strategy to minimize this problem involves burning the fuel under very high oxygen conditions. The standard operating procedure in Brazil requires a furnace operation with an oxygen content at the furnace outlet of about 7% or about 37.5% excess air.

The IPT-rated fuel additive contained a combination of plant extract and an organometallic iron complex. Specifically, 49.2 grams of alfalfa extract were mixed with 7.57 ml of SANTOQUIN® antioxidant, and 37.9 ml of meadowfoam oil. The mixture was combined with AROMATIC 150 FLUID to up to 3785 ml and € 00 ml of the resulting mixture was further mixed with 117 grams of iron naphthenate and 190 ml of iron pentacarbonyl. This formulation was prepared under normal atmospheric conditions with anaerobically transferred iron naphthenate using a syringe. The iron content of the resulting solution was 6% by weight. The residual fuel oil tested at IPT was added with this additive at 813 ppm.

Table 14 shows the particulate matter concentrations observed under treated and untreated conditions. The reduction in particulate matter was quite significant at both 4.5% and 7% oxygen levels, but perhaps the most significant observation was that the particulate matter concentration observed under the treated conditions with respect to at both oxygen concentrations were very close. It is well known that under conditions of combustion with a high excess of oxygen, a significant fraction of heat is lost to the flue gas. Testing showed that by switching from 7% excess oxygen to about 4.5% excess oxygen, a 17% improvement in usable heat was achieved. With the use of the fuel additive tested, this increase in efficiency was accompanied by a 43% reduction in particulate matter emissions.

Table 14. Particulate Emissions at IPT Brasil.

<table> table see original document page 50 </column> </row> <table> Continued

<table> table see original document page 51 </column> </row> <table>

While the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and changes may be made herein in this patent application without departing from the spirit and scope of the invention as defined. through the appended claims. Furthermore, the scope of this patent application is not intended to be limited to the specific embodiments of processes, machines, fabrication, composition of matter, devices, methods and steps described in the specification. As one of ordinary skill in the art can readily appreciate from the description of the present invention, the processes, machines, fabrication, compositions of matter, devices, methods, or steps that exist at present or are to be developed later which perform substantially the same functions or achieve substantially the same results as those of the corresponding embodiments described herein, in this patent application may be used in accordance with the present invention. Accordingly, the appended claims are intended to include within its scope such processes, machines, fabrication, compositions of matter, devices, methods, or steps.

Claims (56)

1. Fuel additive for increasing the combustion characteristics of a high carbon asphaltene fuel, characterized in that it comprises: a plant extract; and an organometallic compound Fuel additive according to Claim 1, characterized in that the plant extract is an extract from a plant of the Leguminosae family. Fuel additive according to Claim 2, characterized in that the plant extract is selected from the group consisting of fescue extract, alpine extract, alfalfa extract and combinations thereof. Fuel additive according to Claim 3, characterized in that the organometallic compound is a hydrocarbon-soluble metal compound containing at least one metal selected from the first and second line of transition metals. Fuel additive according to Claim 4, characterized in that the metal of the organometallic compound is iron. Fuel additive according to Claim 5, characterized in that the organometallic compound is selected from the group consisting of iron pentacarbonyl, iron naphthenate, ferrocene and combinations thereof. Fuel additive according to claim 1, characterized in that the organometallic compound is a hydrocarbon-soluble organometallic compound containing at least one metal selected from the first and second lines of the transition metals. Fuel additive according to Claim 7, characterized in that the metal of the organometallic compound is iron. Fuel additive according to Claim 8, characterized in that the organometallic compound is selected from the group consisting of iron pentacarbonyl, iron naphthenate, ferrocene and combinations thereof. Fuel additive according to claim 1, characterized in that it further comprises an oil-soluble vehicle. Fuel additive according to Claim 10, characterized in that the oil-soluble vehicle is an aromatic solvent. Fuel additive according to claim 10, characterized in that the plant extract is provided in an amount from about 0.01 wt.% To about 10 wt.% Of the additive. for fuel. Fuel additive according to claim 12, characterized in that the plant extract is provided in an amount from about 0.051 wt.% To about 5 wt.% Of the fuel additive. . Fuel additive according to Claim 13, characterized in that the plant extract is provided in an amount of about 0.5% by weight of the fuel additive. Fuel additive according to claim 1, characterized in that it further comprises a material selected from meadowfoam seed oil, a carotenoid, an antioxidant, and combinations thereof. Fuel additive according to claim 1, characterized in that it further comprises meowowam seed oil, a carotenoid, and an antioxidant. Fuel additive according to claim 16, characterized in that the carotenoid comprises beta carotene. Fuel additive according to claim 16, characterized in that the antioxidant comprises a dihydroquinoline. Fuel additive according to Claim 18, characterized in that the dihydroquinoline comprises 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline. Fuel additive according to claim 1, characterized in that the plant extract is extracted by a hydrocarbon-soluble polar or non-polar solvent. 21. A method for improving the combustion characteristics of a high asphaltene coal fuel characterized by the addition of a fuel additive to the high asphaltene carbon fuel, the fuel additive comprising: a plant extract; and an organometallic compound Method according to claim 21, characterized in that the plant extract is an extract of a plant of the Leguminosae family. The method according to claim 22, characterized in that the plant extract is selected from the group consisting of fescue extract, alfalfa extract, alfalfa extract and combinations thereof. . A method according to claim 23, characterized in that the organometallic compound is a hydrocarbon-soluble organometallic compound containing at least one metal selected from the first and second lines of the transition metals. Method according to claim 24, characterized in that the metal of the organometallic compound is iron. The method according to claim 25, characterized in that the organometallic compound is selected from the group consisting of iron pentacarbonyl, iron naphthenate, ferrocene and combinations thereof. Method according to claim 21, characterized in that the organometallic compound is a hydrocarbon-soluble organometallic compound containing at least one metal selected from the first and second lines of the transition metals. A method according to claim 27, characterized in that the metal of the organometallic compound is iron. The method according to claim 28, characterized in that the organometallic compound is selected from the group consisting of iron pentacarbonyl, iron naphthenate, ferrocene and combinations thereof. A method according to claim 21, further comprising an oil-soluble carrier. A method according to claim 21, characterized in that the oil-soluble carrier is an aromatic solvent. Method according to claim 21, characterized in that the high asphaltene carboniferous fuel is selected from the residual fuel oil and coal. A method according to claim 32, characterized in that the plant extract is provided in an amount from about 0.5 ppm to about 10,000 ppm of the amount of the high asphaltene coal fuel. The method of claim 33, wherein the plant extract is provided in an amount from about 200 ppm to about 2,000 ppm of the amount of the high asphaltene coal fuel. A method according to claim 34, characterized in that the plant extract is provided in an amount of about 800 ppm of the amount of the high asphaltene coal fuel. The method according to claim 21, characterized in that the fuel additive further comprises a material selected from meadowfoam seed oil, a carotenoid, an antioxidant and combinations thereof. A method according to claim 21, characterized in that the fuel additive further comprises meadowfoam seed oil, a carotenoid and an antioxidant. A method according to claim 37, characterized in that the carotenoid comprises β-carotene. A method according to claim 37, characterized in that the antioxidant comprises a dihydroquinoline. The method of claim 39, wherein dihydroquinoline comprises 2,2-trimethyl-6-ethoxy-1,2-dihydroquinoline. A method according to claim 21, characterized in that the plant extract is extracted by a hydrocarbon-soluble polar or non-polar solvent. 42. Fuel, characterized in that it comprises a high asphaltene carboniferous fuel and a fuel additive, the fuel additive comprising: a plant extract; and an organometallic compound Fuel according to Claim 42, characterized in that the plant extract is an extract of a plant of the Leguminosae family. Fuel according to Claim 43, characterized in that the plant extract is selected from the group consisting of fescue extract, alfalfa extract, alfalfa extract and combinations thereof. Fuel according to Claim 42, characterized in that the organometallic compound is a hydrocarbon-soluble organometallic compound with a metal selected from the first and second lines of the transition metals. Fuel according to Claim 45, characterized in that the organometallic compound is selected from the group consisting of iron pentacarbonyl, iron naphthenate, ferrocene and combinations thereof. 47. Fuel according to claim 42, characterized in that the high asphaltene carboniferous fuel is selected from residual fuel oil and coal. Fuel according to claim 47, characterized in that the plant extract is provided in an amount from about 0.5 ppm to about 10,000 ppm of the amount of the high asphaltene coal fuel. Fuel according to claim 48, characterized in that the plant extract is provided in an amount from about 200 ppm to about 2,000 ppm of the high asphaltene coal fuel. Fuel according to claim 49, characterized in that the plant extract is provided in an amount of about 800 ppm of the high asphaltene coal fuel. Fuel according to Claim 42, further comprising a material selected from meadowfoam seed oil, a carotenoid, an antioxidant and combinations thereof. Fuel according to claim 42, characterized in that it further comprises meadowfoam seed oil, a carotenoid, and an antioxidant. Fuel according to Claim 52, characterized in that the carotenoid comprises β-carotene. Fuel according to claim 52, characterized in that the antioxidant comprises a dihydroquinoline. Fuel according to Claim 54, characterized in that the dihydroquinoline comprises 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline. Fuel according to Claim 42, characterized in that the plant extract is extracted by a hydrocarbon-soluble polar or non-polar solvent.