MX2011013017A - Fuel paste based on hydrophobe pyrogenic silica. - Google Patents

Abstract

The present invention is related to a fuel paste that uses a hydrophobe pyrogenic silica, as a viscosifier, compatible with combustible organic liquids for providing thixotropic properties that facilitate and improve the dosage and burn of the fuel paste. Such properties are shown by the viscosity drop at a constant shearing speed and by the viscosity drop due to the increase in the shearing speed. The present invention may be performed with additives that provide heat and odour according to the required applications; the manufacture of the invention is easy and may be formed with biodegradable and environmentally friendly ingredients. In addition, the present invention has the following characteristics: an improved flame life, optimum performance in humid environments, safety and handle due to its high flashpoint (higher than 95°C), and specially the capacity of being used after being wet; all these characteristics were proved by comparative tests of performance with state-of-the-ar t products and standardized methodologies for the flashpoint case. The present invention may keep the flame burning by the required time for surpassing, in terms of duration, the products currently available on the market; it also may burn humid coal, which has not been previously presented by the state-of-the-art products.

Description

COMBUSTIBLE PASTE BASED ON SÍLICA PIROGÉNICA HIDROFOBA DESCRIPTION OBJECT OF THE INVENTION! The present invention relates to a thixotropic fuel paste comprising a hydrophobic pyrogenic silica and a hydrophobic organic liquid, either natural or synthetic.

FIELD OF THE INVENTION The present invention falls within the field of fuels in different physical states. Particularly, it refers to fuels in the form of semi-solid pulp.

BACKGROUND It is well known in the art to make combustible substances, called fire initiators, which aid the ignition of others such as firewood, charcoal, pressed coal dust briquettes and other materials. These fire initiators, which ignite with an independently-generated flame such as that of a match or a gas lighter or any burning material, are based on a pure liquid organic fuel or mixtures of various fuels of this type and are commercially presented in different forms from liquid, paste or solid. Usually, said solid compositions are manufactured by impregnation of different solid substrates such as paper; cardboard, blocks and wood sawdust; while the pastes are made by dispersing thickener materials in the fuel.

Liquid fire initiators have disadvantages; a very important one is that they flow when they are deposited on the material to be ignited, causing the ignition time to initiate the combustion of the substrate to be insufficient. This forces jusaf an excess of initiator with the risk of a retro inflammation and explosion of the material eft its container. Another disadvantage is during transportation and presentation for sale on the shelves of shopping centers and storage in places of use cpmo homes and warehouses, as they represent a significant risk of fire start or spread in the event of an outbreak of fire . In addition, if a spill of the initiator occurs in a situation of fire contingency, the risk of spreading makes its commercialization unjustifiable. Finally, it is worth mentioning that no initiator known in the field offers a solution for humid environments, such as that which occurs after a heavy rain, in which the wetting of the initiator matrix 0 of the substrate quickly occurs, and consequently its inability to burn.

In an attempt to minimize the problems with the largest initiators, paste formulations have been proposed by mixing the organic liquid fuel with a sufficient amount of an absorbent or thickener. Examples of these pastes are found in Swiss patents 470471 and 482008 which describe non-thixotropic alcohol-based pastes in which an inorganic carrier consisting of silicon dioxide particles of size in the range of 3 to 40 microns, alone or in combination with other inorganic substances such as titanium, zirconium or aluminum oxides: or at least one carbonate of alkali or alkaline earth metals.

U.S. Patent 3964880 discloses a paste based on ethyl alcohol with better characteristics, but still not tropic thix, which uses various compounds such as cellulose esters and polyvinylpyrrolidone in addition to high purity silicon dioxide as thickening agents. As noted, in practice the combustible organic liquids that can be used are severely limited and the liquid generally has to be an alcohol. This is undesirable since paraffins are preferable as a liquid organic fuel since alcohols are more expensive, more volatile and have a lower flash point and their use in large quantities as required as fuel presents a significant toxicity problem. Even apart from the desyentajas i that effectively limit the use of alcohols as fuels, the known pastes are not very satisfactory since the liquid fuel flows once the paste is ignited, spilling through the surface in which it is placed, reducing the concentration of the initiator, reducing the concentration of heat and representing a risk of fire in undesirable places. Another characteristic of alcohol-based pastes is that they are consumed quickly.

It is more desirable for various reasons to use the fuel composition in a liquid form but without the problems of the aforementioned liquid organic fuels; this would avoid the need to form unitary pieces of solid presentations, simplify packaging and allow the user to easily dose the amount of composition desired for a particular occasion. In addition, it would allow the user to place the composition without having direct contact with it and would facilitate an intimate contact between the fuel to be ignited and the fire initiating composition.

Then, a combination of properties of fluidity in its dosage and of firm consistency and absence of fluidity during its ignition and the use of liquid fuels of High flash point and low volatility are desirable to provide greater security in its transportation, display, dosage and better performance in its use as a fire starter. In this context, the state of the art shows different approaches to obtaining an initiator with better qualities. The patent US 3801292 discloses a combustible composition in the form of a paste that solidifies upon ignition by the polymerization of a urea-formaldehyde resin included in its formulation, however, a disadvantage thereof is the inclusion of an acid catalyst and the generation of compounds such as triethylamine and formaldetyde, both chemical compounds considered high toxicity and, additionally, the generation of other toxic products from the combustion of resin ^ such as nitrogen oxides and carbon nitrogen compounds, apart from formaldehyde, which represents a Great risk for users and people around the place of use of the composition.

Japanese patent JP2000351981 discloses a very particular fuel composition in the form of a paste which uses as a thickening agent a silicone polymer and as an organic fuel liquid a hydrocarbon of the petroleum fraction with a aromatics concentration of less than or equal to 5% and a difference of less than 10 degrees Celsius between the distillation temperature of 10% and distillation of 90%, and does not mention liquid organic fuel alternatives, so it is very limited.

On the other hand, the Spanish patent ES8301498 describes a combustible paste that incorporates expanded perlite to modify the density and the rate of combustion of the paste and avoid, by means of said incorporation, the flow of it while it burns.

In the art there are initiators designed specifically to burn even in spite of the inclement weather. US Patent 5967769 describes an outdoor fire initiator device designed to withstand moderate winds, but I do not mention anything about turning on when wet.

On the other hand, pyrogenic silica has been reported in the art as an additive for formulate fire initiators. In the US patent 4286968 the use of the pyrogenic silica in order to increase the flame temperature of a Cuyo formulation Fuel is an acetal resin. It should be noted that the product proposed in this I The document does not have a thixotropic character, and silica is not used as a regulator of The Theological properties of the product. U.S. Patent 5773706 mention to the pyrogenic silica as a fuel stabilizer based on naphthas, however not mentioned as a Theological properties modifier or itself as a component fundamental for the production of a thixotropic fuel paste. On the other hand, it is well known in the art that pyrogenic silica, including also hydrophobic silica, they present a harmless character in the environment, so they can be considered safe in the event of ingestion or inhalation scenarios.

BRIEF DESCRIPTION OF FIGURES Figure 1. Graph of viscosity versus time behavior at different shear rates for the fuel pulp of Example 1. i Figure 2. Graph of viscosity behavior against shear rate for the fuel paste of Example 1.

Figure 3. Graph of viscosity versus time behavior at different shear rates for the fuel pulp of Example 2.

Figure 4. Graph of viscosity behavior versus shear rate for the fuel pulp of Example 2.

Figure 5. Comparative photographs that illustrate the combustion process of the different ! i combustion initiators within the flame time-of-life test.

Figure 6. Comparative photographs illustrating the combustion of coal generated by: different combustion initiators.

Figure 7. Photographs illustrating the combustion of moistened coal using as i initiator to the paste of Example 1.; Figure 8. Photographs illustrating the combustion of the initiator on a tile fragment i moistened, without apparent damage to the fabric. i DETAILED DESCRIPTION OF THE INVENTION It is an object of this invention to provide a combustible paste with the qualities of being tropic tixo to offer the best flow properties according to the conditions of use, that is, fluid in its dosage and semisolid in its ignition. .

The object of the invention is also the use of pulp to: reduce the risk of initiation and propagation of fire, facilitate handling in its dosage, prolong the duration of the combustion with respect to similar compositions described in the art, avoid I liquefaction of the product at the moment of being inflamed by maintaining its character of pasta While it is consumed, ignite in places of high humidity (wet sites), return to work as a combustion initiator after having wetted itself, be made with ingredients considered to be friendly to the environment and biodegradable, include additives that impart color and odor according to the needs of application, present a simple elaboration and contain components considered as safe according to title 21 of the CFR (Code of Federal Regulations) of the agency FDA (Food and Drug Administration) that corresponds to regulations for the use of additives and ingredients for food and drugs for human consumption, among others.

The fuel pulp of the present invention has a composition comprising: 1) an organic fuel liquid or a mixture of several, 2) a hydrophobic pyrogenic silica or a mixture of several that works as a viscosifier and that imparts properties thixotropic, and 3) additives that impart color and odor to the mixture.

The organic liquid fuels that can be used, alone or in combination, in the present invention include: fatty acid esters, such as methyl esters, ethyl esters and propyl of 12 to 25 carbons from the saponification of vegetable oils, and / or fats or oils of animal origin, biodiesel, dibasic esters of dicarboxylic acids of 2 to 10 carbons such as those from dicarboxylic acids such as acid glutaric, glutamic and related, or esters from any source of triglycerides or fatty acids in nature. ' Among the useful vegetable oils are mentioned as an example, and without being the jista Limiting, those of cotton, safflower, soybeans, corn, flaxseed, olive, and the like. In the present invention, vegetable oils and / or fats or oils of origin can be used, like organic liquid fuels. Also included in the present invention are organic liquid fuels to hydrocarbons, such as kerosene, naphthas, diesel oil, mineral turpentine or mineral oils. In general, the proportion of the combustible organic liquid in the composition is 20% to 90% by weight, and more preferably between 50% and 90% by weight of the total composition.

The viscosifying materials that can be used, alone or in combination, comprise the hydrophobic pyrogenic silica dispersible in organic media, for example the HDK® H15 marketed by the company Wacker Silicones.

The proportion of hydrophobic pyrogenic silica is between 1% and 50% by weight, and more preferably between 5% and 20% by weight of the total composition.

These hydrophobic pyrogenic silica are widely known in the art as free-flowing agents especially for moisture sensitive substances (eg peroxides, pigments, printing toners, among others), thickeners for silicone sealants, polysul fi ner, polyurethane and acrylates, filling and coating agents, and ran anti-deposition agents in printing inks and zinc-rich paints; however, the literature does not mention its application in combustible pastes of any kind. Hydrophobic pyrogenic silica useful for this invention are described in U.S. Patent Nos. 2802850, 3015645, 3053627, 3269799, 4072796, 4477412, 5009874, 5919298 and British Patent 1110331. i i From the previous quotes, a description of its obtaining as an illustration is incorporated here i and example. In general, said silica is produced from a pyrogenic silica as a precursor. Said precursor is produced by the hydrolysis of silicon tetrachloride vapor in a hydrogen flame with oxygen, as shown by the following reactions: 1) 2H2 + 02? 2H20 2) SiC14 + 2H20? Si02 1 + 4HCl t 3) The global reaction is: SIC14 + 2H2 + 02? Si02 1 + 4HC1 1 (at 1800 ° C) In the combustion process, molten microparticles of between 7 and 30 millimicrons are formed. These particles contain a surprisingly large surface area;, which ranges between 100 and 400 square meters per gram. During the cooling process, the particles collide and join together, forming chain-like aggregates. Finally, the residual hydrogen chloride adsorbed on pyrogenic carbon is reduced to less than 200 ppm by calcination. In this way the precursor is achieved, which must be chemically modified to acquire hydrophobic character and gain compatibility with organic liquid compounds. For this, the pyrogenic syllable is subjected to a chemical reaction with one or more compounds comprised within one or more of the following groups: a) Organosilanes, described by the formula Rl to H b SiX 4-a-b, b) Organosiloxanes, described by the formula R2 n SiO (4-n) / 2, or c) organodisilazanes, described by the formula (R 3 3 Si) 2 NH, io; Where each R1 is an independently selected alkyl radical and comprising from 1 to 12 carbon atoms; R2 is independently selected and I cor nded hydroxy, chloro, and alkyl radicals of between 1 to 12 carbon atoms, as long as minus 50% (in molar terms) of the substituents R 2 are alkyl radicals; R3 is independently selected and comprises hydroxy, chloro and alkyl radicals I entered 1 to 12 carbon atoms, as long as at least 50% (molar terms) of the R3 substituents are alkyl radicals; each X is selected independently of group of halogens, of the alkoxide radicals comprising from 1 to 12 atomic atoms Í carbon, acyloxide radicals comprising from 1 to 12 carbon atoms; 8 = 1, ^ 0 3; b = 0 ol; a + b = 1, 2 or 3, as long as b equals 1, then a + b = 2 or 3; by last n is an integer from 2 to 3 inclusive.

U.S. Patent No. 5919298 describes the preparation of pyrogenic silica hydrophobic as a two-step process. ! In the first, an aqueous suspension of pyrogenic silica is formed which comes into contact with a compound either from the group of organosilanes, organosiloxanes, or organodisilazanes described above in the presence of a catalytic amount of acid, in the presence of an organic solvent miscible with water. In the second step the suspension water that contains the pyrogenic silica comes in contact with an organic solvent water immiscible with a solvent / silica base cup weight greater than 0.1: 1.0 in order to effect the separation of the hydrophobic pyrogenic silica from the aqueous phase. j The product obtained from such reaction is perfectly compatible with fuels The aforementioned organic liquids and their combustion products have no toxicity and besides the combustion residue is the hydrophobic pyrogenic silica originally used in the formulation, thus offering safety in comparison with other thickeners known in the art. They are widely known commercially as HDK H15®, from the company Wacker Silicones (Germany) and Cab-O-Sil® from the company Cabot (Tuscola Illinois), to name a few.

It is possible to add other additives to the composition such as flavorings that impart and give off fragrances such as certain woods like mesquite or onion! by example, to make its use pleasant. 1 The working up of the composition of the present invention follows known procedures in the technique and consists of placing the organic fuel liquid in a container of the appropriate capacity and equipped with a variable speed agitator. ! The thickening agent is added slowly under gentle stirring long enough for its complete incorporation. ' During this process, the mixture will increase its viscosity until reaching the consistency that goes from a highly viscous fluid to that of a soft paste, depending on the formulation in particular. If additional additives are used, the point of processing for its Addition is at the beginning with the organic combustible liquid.

The characteristic details of this novel initiator are clearly shown in the following examples and in the following accompanying figures, highlighting both the advantages and the application of the invention. < i i i! Figure 1 is a graph showing the thixotropic behavior of the one corresponding to Example 1. On the x-axis appears the time in seconds, and in the the viscosity appears in units of Centipoises (CP). Each curve corresponds to the constant shear rate, with the 20 RPM being the one corresponding to the highest viscosity values, and the 30, 50, 60 and 100 RPM's consecutively descending.

Figure 2 is a graph showing the behavior of the viscosity at different shear rates (5, 10, 30, 60 and 100 RPM'S). The shear velocity appears on the x axis, and the viscosity at the CP appears on the y axis. : Figure 3 is also a graph showing the thixotropic behavior of Example 2. On the x-axis the time appears in seconds, and on the y-axis the viscosity appears in units of Centipoises (CP). The pink curve corresponds to 30 RPM, the green one to 50 RPM, the red one to 60 RPM the purple one to 100 RPM and the blue one to 20 RPM.

Figure 4 is a graph showing the viscosity drop in the face of increased shear rate (5, 10, 20, 30, 50, 60, and 100 RPM's). The steady state viscosity values decrease as the shear rate increases, meeting the definition in the art of a thixotropic fluid. Figure 5 comprises 9 images of the combustion process for each initiator during the flame lifetime test. The image (a) corresponds to the combustion of the "Gél Alcohol"; the image (b) to the final state of combustion of the "Gel Alcohol"; the iniag ^ n (c) shows the final state of the combustion of Alcosol, and the images (d) and (f) show the flame generated by the paste of example 1, while the (e) and (g) sample the final state of its combustion. The image (h) and (i) shows the flame of the paste of example 2.

Figure 6 contains six images that illustrate the comparative photographic development of combustion process of equal masses of carbon using the paste of example 1 and the "Gel Alcohol" competitor. In (a) the amounts used for both pasta are appreciated; of the example 1 as "Gel Alcohol". In (b) the appearance of the coal mounds is seen just before starting combustion. Images (c) and (d) show the pasta, example 1 on, starting to consume coal. The image (e) shows the competitor unable to start the combustion process, and finally the image (f) shows the final state of combustion for both.

Figure 7 contains seven images that describe the combustion process of a defined quantity of previously moistened coal, to which is added an amount additional water to corroborate its ignition capacity. In (a) the appearance appears original of the initiator of example 1. Image (b) shows the prehumed carbon forming a mound concealing the initiating paste of example 1. In (c) it is observed the flame due to the on igniter (see circle), while in (d) the I first evidence of coal combustion (see marked area). The image (e) rjevela the addition of water that extinguishes the combustion of the system.

However, in the image (f) it looks like the initiator, after being turned on again with a match, retakes the flame despite the additional moisture in the coal, and the image (g) shows the final state of combustion of the coal despite the added water.; Figure 8 presents 6 images illustrating the combustion of the dough on a previously moistened cotton cloth fragrance. In the image (a) appears the moistened cloth and with the initiator of example 1.

In (b) to (e) appears the expansion of the flame and the progress of the combustion process of the initiator, without affecting the integrity of the fabric, while in (f) the final state of the combustion is appreciated.

I EXAMPLES Example 1. General typical procedure for the preparation of the fuel paste.

In a beaker of 1 liter capacity, 180 g of methyl esters of soybean oil and 20 g of hydrophobic pyrogenic silica (Wacker HDK H15) are placed. A 30 cm glass rod is introduced into the vessel as an agitator and mixed until completely incorporated. It will result in a creamy paste that tends to decrease its viscosity as the intensity of agitation increases. The flash point, according to the method ASTM D56"Standard Test Method for Flash Point by Tag Closed Cup Tester" is greater than 95 ° C, The viscosity Brookfield at constant shear rate (readings made with needle 7), appears as graph as a function of time in figure 1. The decrease in cost i for each curve shows the thixotropic behavior of the preparation. On the other hand, Figure 2 shows the viscosity behavior at different shear rates. Such a pattern implies that steady-state viscosity values decrease as the shear rate increases.

This means that the mixture is less viscous at higher stresses. This pronounced decrease in viscosity meets the definition in the art of a thixotropic fluid. i I Example 2. Using the procedure of Example 1, a fuel paste is prepared using now 170g of methyl soyate and 30g of hydrophobic pyrogenic silica. The flash point, according to the method ASTM D56"Standard Test Method for Flash Poinjt by Tag Closed Cup Tester" is greater than 95 ° C. The Brookfield viscosity at constant shear rate (readings made with needle 7) appear as graphs as a function of time n Figure 3. The descending shape of each curve in the figure shows the thixotropic behavior of the pulp. Compared to Example 1, the viscosity drops are more drastic. On the other hand, Figure 4 shows the viscosity drop at a variable speed. As in the previous example, the mixture is much less viscous with larger efforts, so the pronounced decrease in viscosity in this graph meets the definition in the art of a thixotropic fluid.

Table 1. Life times of the flame for each initiator.

J Example 3. The portions indicated in table 1 of the tables are placed on a vitrified earthenware. the following materials: paste made in example 1, paste made in example 2, a competitor product in the form of paste ("Gel Alcohol®" manufactured by Mek) based on alcohol and another solid competitor based on alcohol ( "Alcosol®" manufactured by Productos Pielux SA de CV). The products are spread over a surface The results appear in Table 1 and Table 2, while photographs of the combustion process for each initiator appear in Figure 5.

Table 2. Results for the evaluation of the life time between the different combustion initiators.

It should be noted that the area is limited to 10 cm x 10 cm and the time that elapses from the time the flame appears in the initiator until it disappears, a period called "flame life time" or TVF, is measured. j In the case of both alcohol-based competitors the material exceeded the traced surface (see images (b) and (c) of figure 5), since during the combustion process it was liquefied, reaching undesirable places, while the material of example 1 was maintained without leaving the original surface (see images (e) and (g) of figure 5).

The results show that the paste of example 1 remains lit between 5.9 to 6.5 i times more time than the solid alcohol competitor and 1.86 to 2.8 times longer than the "Gel Alcohol" competitor. The paste of Example 2 is kept lit between 7.1.5 to 6.42 times longer than the competitor of solid alcohol and 3.1 1 to 2.03 times more than the competitor "Gel Alcohol" (see Table 2). : Example 4. On a conventional rotisserie, 4.9g of the paste obtained in the Table 3. Coal values and initiator used, and life times during combustion: Example 1 and 7.3g of the competitor product based on alcohol ("Gel Alcohol" Mek). The amount indicated in Table 3 of carbon is placed for each initiator and in the manner of a vault, and the initiator is ignited with the aid of a suitable means of ignition, such as a match, or an iron wire with petrol paper soaked at the tip. The results ^ i appear in table 3, and photographs of the process in figure 6. The paste of example 1. ignited without problems, and the duration and intensity were sufficient to consume coal, while the "Gel Alcohol" flame did not last long enough to burn the coal. Comparatively the duration of the flame of the product of the Example 1 is 6.19 times greater than the competitor in these conditions, even though 1.49 times more mass was used.

This shows that the flame life of example 1 is also longer than that of the competitor in these circumstances, and favors the ignition of coal.

Example 5. On the same conventional roaster, 58.55 g of paste of example 1 are placed, and 506.8g of carbon (8.64 times more weight than the initiator) are soaked in 1075.3g of water by immersion in a bucket, (see Table 4). The moistened coal is placed in returned to the paste to form a vault. The paste is lit in the same way as in the .. 1 example 4, and the life time of the paste of example 1 is recorded. At 6 minutes, the amount of water indicated in Table 4 is added to the coal, and the mass is re-ignited of initiator of example 1 in the same way as described in example 4. It is measured he ignition time of the paste and the combustion of the coal is monitored. The results they indicate that the paste ignited without problem to the coal in spite of containing a 14.3% of load of water with respect to the original coal mass (see figure 7). On the other hand, the initiator he took up the flame without problem despite the amount of water poured, and logically a successful combustion of all the wet coal (See photographs in figure 7). ? Table 4. Specifications for the combustion of a moistened coal, to which an additional amount of water is added during the process.

Example 6. About 24.4g of cotton cloth is immersed in 300ml of water to retain the amount of water indicated in Table 5. 61.1g of the pulp described in exercise 1 is added and ignited (Cup paste / water = 0.85 ). The ignition time is monitored and the final state of the garment is evaluated once the flame has been extinguished (see figure 8).; The results show that the paste ignites on the wet cloth without any complication, and that at the end of the combustion of the paste, the cloth remains without burns. It should be noted that, as in the previous cases, the paste when ignited does not liquefy; on the contrary it retains its consistency and the most important thing is that it does not burn the fabric after 380 seconds of ignition.

Table 5. Specifications for the test referred to in example 6.

Example 7. In a porcelain crucible place 4.7g of initiator (see Table 6) and enough water is added to cover it completely.

Table 6. Ignition times of initiators subjected to immersion with water.

The initiator is left to stand in the water for five minutes, and then the water is carefully distilled. The initiator is turned on in the manner described in example 4 and the time it takes to generate the flame is measured. The results appear in table 4. Here it is clearly perceived that competitors lose their ignition capacity in contact with water, while the paste of example 1 retains its ignition capacity.

Claims (10)

CLAIMS | Having described my invention enough, I consider it a novelty and therefore I claim as my exclusive property, what is contained in the following clauses: i

1. A combustible composition in paste form characterized by being thixotropic and because it comprises: a) at least one hydrophobic pyrogenic silica b) at least one combustible organic liquid.

2. The fuel composition according to claim 1, characterized in that it employs at least one hydrophobic pyrogenic silica belonging to the group of hydrophobic pyrogenic silica compounds composed of a pyrogenic silica precursor chemically modified by one or more of the compounds of one or several of the following groups : a) Organosilanes: described by the formula R1 aH b SiXt a-b, j b) Organosiloxanes, described by the formula R2 n SiO (4-n) / 2, or c) Organodisilized, described by the formula (R 3 3 Si) 2 NH, wherein each R 1 is an alkyl radical independently selected and comprising from 1 to 12 a tpmós of carbon; R is independently selected and comprises hydroxy, cidro, and alkyl radicals of from 1 to 12 carbon atoms, as long as at least 50% (in mole terms) of the substituents R 2 are alkyl radicals; R3 is independently selected and comprises hydroxy, chloro and alkyl radicals of between 1 to 12 carbon atoms, as long as at least 50% > (molar terms) of the substituents R3 are alkyl radicals; each X is independently selected from the group of halogens, from the alkoxide radicals comprising from 1 to 12 carbon atoms, acyloxide radicals comprising from 1 to 12 carbon atoms; a = 1, 2 or 3; b = 0 or 1; a + j b = 1, 2 or 3, as long as b equals 1, then a + b = 2 or 3; and finally, there is a whole number from 2 to 3 inclusive.

3. The fuel composition according to claim 1, characterized in that it contains at least one organic combustible liquid or a mixture of several and includes one or more of the following options: esters of fatty acids, such as methyl, ethyl and propyl esters of 12 to 25 carbons from the saponification of vegetable oils, and / or fats or oils of animal origin, biodiesel, dibasic esters of dicarboxylic acids of 2 to 10 carbons such as those from dicarboxylic acids such as glutaric acid, glutamic acid and affines, or esters from any source of triglycerides or fatty acids in nature; vegetable oils exemplified by, and without being the limiting list, lps of cotton, safflower, soybeans, corn, flaxseed, olive, and the like, as for example and without being the limiting list, those of cotton, safflower, soybeans, corn, flaxseed , olive tree and the like; hydrocarbons, such as kerosene, naphthas, diesel oil, mineral turpentine and mineral aerials.

4. The fuel composition according to claim 1 in which the additives can be compounds that impart characteristic aromas of wood or that remember vegetables, legumes and / or food.

5. The fuel composition according to claim 1, characterized in that the proportion of the organic liquid fuel is from 20% to 90% of the total weight of the fuel paste and preferably from 50% to 90% of the total. I

6. The fuel composition according to claim 1 characterized in that the proportion of hydrophobic pyrogenic silica is from 1% to 50% of the total of the weight of the fuel paste and preferably from 5% to 20% of the total. i

7. The fuel composition according to claim 1 characterized in that it is capable of generating a sustainable flame in a certain amount of coal, the latter being with a moisture load greater than 10% of the weight thereof.

8. The fuel composition according to claim 1 characterized in that it does not lose its potential to function after immediate contact with water.

9. The fuel composition according to claim 1, characterized in that it has a flash point, greater than 95 ° C according to the method ASTM D56"Standard Test Method for Flash Point by Tag Closed Cup Tester" and therefore safe to store and transport.

10. The fuel composition according to claim 1 characterized in that upon undergoing the combustion process, it does not liquefy avoiding spills and maintaining combustion at a certain point.