JPH02132188A - Improved method of combustion of liquid hydrocarbon - Google Patents

Abstract

PURPOSE: To improve the combustion efficiency and reduce NOx discharge, by burning liquid hydrocarbons in the presence of an additive composition of a ferrocene (derivative) compound and a liquid organic carrier.

CONSTITUTION: In the presence of (A) an additive composition consisting of (i) a ferrocene (or it derivative) compound represented by the formula (R, R' are each H, an alkyl, cycloalkyl, aryl, or heterocyclic group) and (ii) a liquid organic carrier for dissolving the component A such as aromatic solvent, aliphatic solvent or petroleum solvent having a high ignition point, (B) a liquid hydrocarbon consisting of crude oil, heavy oil, lubricant, turbine oil, transformer oil, kerosene, jet fuel, fuel oil, grease, or asphalt with a Conradson carbon content of 1% or more is burnt.

COPYRIGHT: (C)1990,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for modifying the combustion of liquid hydrocarbons and as a result reducing NO 2 emissions. ε Problems to be solved by the prior art and the invention M] Liquid hydrocarbons are widely used in ignition and internal combustion devices such as oil-fired burners and internal combustion engines, and the common problems associated with such combustion devices are: is to release NO,
Reduce NOx emissions
Although many attempts have been made in the past to reduce x, these attempts usually resulted in a decrease in combustion efficiency. Oil-fired furnaces and boiler equipment are used throughout the world to generate heat and electricity. Typically, petroleum distillates such as fuel oil are used in such oil-fired burners. Direct combustion of extracted crude oils is very rare, as burning them considerably increases the emissions of pollutants, especially oil smoke.

It has long been recognized that additives can be incorporated into organic materials used in oil-fired furnaces and the like. A particularly suitable additive is fecutene, which is one of a number of dicyclopentadienyl iron compounds; examples of these additive components are disclosed in U.S. Pat. No. 3,535,356. This patent states that ferrocene and its derivatives are used in various organic compositions, particularly gasoline and lubricating oils, turbine oils, transformer oils, kerosene, diesel fuel, jet fuel, fuel oils, greases, asphalts, waxes, pesticides, etc. It is said to be a valuable additive for hydrocarbons, including other petroleum products. However, this reference does not state what effect, if any, Huekousen has on the combustion of these petroleum products. However, in US Pat. No. 3,122,577, ferrocene is described as suitable as an anti-knock agent in gasoline compositions. U.S. Pat. No. 3,341,211 discloses the use of ferrocene in liquid hydrocarbon fuel oils.

The purpose of using ferrocene is to improve the ignition and combustion characteristics of fuel. According to that embodiment, the use of such ferrocenes in fuel oils reduces the presence of carbon in the combustion gases and reduces the amount of deposits in combustion devices.

However, none of these references consider the use of Huekoutocene and its derivatives in liquid hydrocarbons to achieve improved combustion efficiency and reduced No2 emissions. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, a method is provided for combusting liquid hydrocarbons having a Conradson carbon content of greater than 1% in a combustion furnace while maintaining No. 2 emissions at an acceptable X level. Ru. In this method, a sufficient amount of a compound of the following formula (wherein R and R' are each independently hydrogen, alkyl, cycloalkyl, in the presence of an additive composition comprising a compound selected from the group consisting of ferro7ine and its derivatives, wherein aryls is a bicyclic group; combusting said liquid hydrocarbon, and adjusting the amount of excess air required relative to the amount of said liquid hydrocarbon combusted to a low level in the presence of said composition; X 1) the amount of No emissions in the combustion product, and X 2) the amount of excess air that the additive composition The use of such an additive composition results in a significant reduction in smoke emissions, as measured by carbon in the granular lye, as well as combustion, characterized by a lower combustion efficiency than in the absence of the same level of combustion efficiency. Improved efficiency can be achieved. Surprisingly, if we can reduce the amount of excess air required, we can also reduce the amount of N
It has been found that O emissions can be reduced.

Xffl Formation and Operation The present invention finds use in improving the combustion of liquid hydrocarbons of type q in either open flames or internal combustion. Examples of bare sizes include various burner devices such as oil-fired burners used in heating devices. There are, of course, many examples of various types of internal combustion systems, including various gasoline engines as well as jet engines. ? ! ! Liquid hydrocarbons that are combusted either by fire or by internal combustion can be selected from various groups. Liquid hydrocarbons of various types can be petroleum distillates intended for combustion, or they can be hydrocarbon waste products. The present invention is suitable for burning hydrocarbons selected from the group consisting of gasoline and other petroleum products including lubricating oils, turbine oils, transformer oils, crocins, jet fuel T4, fuel oils, greases and asphalts. Particularly suitable. Although the invention used to burn these various types of liquid hydrocarbons is applicable in all cases, the principles of the invention will be demonstrated with respect to the field of burning heavy oil, medium oil, light oil, etc. By using additives, the excess air requirement can be adjusted to a low level.
It has been found that there are a variety of oil-fired burner systems commonly used in heating plants and thermoelectric power plants that can reduce NO emissions when burning these various liquid hydrocarbons.

Because of the advantages of the present invention, as-extracted crude oil can now be combusted in these common types of oil-fired burner equipment, including multilayer high-grade boilers, used to generate heat and electricity.

A problem with existing units that burn crude oil is that they increase pollutants in the emissions. According to the invention, crude oil is processed in addition to being injected into an oil-fired burner. Such treatments include the necessary dilution of the crude oil with flammable solvents and/or heating of the crude oil to reduce its viscosity. Usually, there is a collecting tank Ml(fm) provided for storing crude oil.The crude oil may or may not be processed in the collecting tank.The crude oil can be moved from the collecting tank and a small amount is needed at the time. Preferably, the crude oil is treated with a suitable solvent and placed in a temporary storage tank, which is optionally heated.The treated crude oil is then conveyed to an oil-fired burner using suitable bongs and piping.

According to the present invention, before burning crude oil in an oil burner,
An additive composition is introduced into the crude oil. Typically, the additive composition is introduced into the crude oil either in the temporary storage tank in which the crude oil is initially processed or in the piping that transports the crude oil to an oil-fired burner. When an atomized additive composition is to be sprayed together with crude oil, such as crude oil that is sprayed in preparation for combustion, an injection nozzle may be included in the oil-fired burner, if desired. The additive composition is included in the crude oil in an amount sufficient to modify, to some extent, the combustion efficiency when burning the crude oil. The additive composition comprises: 1) a group consisting of ferrocenes and derivatives thereof represented by the following formula (1), where R and R' are each independently hydrogen, alkyl, cycloalkyl, aryl, or a bicyclic ring; and 2) a frozen organic carrier that dissolves said ferrocene. With respect to formula (1), the term alkyl refers to branched or straight chain alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, n-butyl, hexyl or hegthyl. The term cycloalkyl refers to lower dichloroalkyl groups having 3 to 7 carbon atoms, such as cyclobentyl or cyclohexyl. The term aryl refers to an organic group obtained from an aromatized metal by removing a single hydrogen atom. Such groups include substituted phenyls such as phenyl and lower alkyl substituted phenyls. These groups include tolyl, ethyl phenyl, triethylphenyl, octotrophenyl, such as ethyl phenyl, and nitrophenyl. The term heterocyclic group includes pyrroI, pyridyl,
This refers to furfuril, etc. Aryl or bicyclic groups generally have up to about 15 carbon atoms.

Dicyclopentadienyl iron is usually referred to as "ferrocene." Therefore, the compound of formula (I) above is considered to be ferrocene and its derivatives. Preferred compounds of formula (1) include dicyclopentadienyl Iron, di(methylcyclopentadienyl)iron, di(ethylcyclopentadienyl)iron, methylferrocene, ethylferrocene, n-
These include butylferrocene, dihexylferrocene, phenylferrocene, m-tolylferrocene, didecylferrocene, dicyclohexylferrocene and dicyclobentylferrocene.

The organic carrier is of a type that dissolves the selected dicyclopentadienyl iron. First, the liquid carrier has a high flash point and a viscosity at operating temperature that allows it to be injected when required by the injection nozzle. Preferably, the liquid carrier has a flash point greater than 74°F (about 23°C) and a boiling point greater than 95°F (35°C). The viscosity of the carrier is usually 5 at 20°C.
0 centiboaz or less, preferably in the range of 0.3 to 3.0 centiboaz at 20°C. Preferably liquid organic carriers, or solvents, are either aromatic or aliphatic. Aromatic solvents include xylenes, toluene, and Solvesol 100 (trademark, manufactured by Inherial Oil), a mixture of benzene and naphthalenes with a flash point of 100°Ft (approximately 38°C). ). Suitable aliphatic solvents include alcohols such as hexanol and octanol. Other hydrocarbon solvents include petroleum-based solvents such as fuel oil, gelothene, and petroleum spirits. Solvents of this type have low viscosities and functional flash points. The solvent is stable and will dissolve the selected additives. Of course, the chosen solvent is non-toxic when combusted. It should be appreciated that the additive composition can include a variety of commercially available dyes to impart a unique color to the composition and distinguish it from those used in oil-fired furnace operations.
Containers of additive compositions should be explosion safe and convenient to handle. Also, tanks containing additive compositions should be suitably equipped to minimize the risk of explosion and fire. The amount of additive composition used varies depending on the type of crude oil being burned. Generally, the amount of additive composition used ranges from 0.1 ppn to 100 ppl of iron in the composition based on the amount of crude oil delivered to the oil burner. The preferred amount of additive composition used is 1 pI to 5 13 pIf based on the amount of crude oil sent to the burner in terms of iron.
It is. According to the present invention, crude oil with a high asphaltene content can now be burned in an oil-fired burner that was previously unable to change TP. Crude oil containing high concentrations of asphaltenes usually contains asphaltenes in the range of about 1% to 15% by weight. Asphaldenes are a group of high molecular weight substances. Common to crude oil, asphaltenes are hard solids with melting points well above 150°C. For example, a type of graphamite group has a temperature of 315°C.
It has a melting point of Asphaltenes are soluble in petroleum naphtha in the range 0-60% and in CS2 in the range 50-60%. Asphaltenes are easily precipitated by N-heptane, which allows the asphaltene concentration of crude oil to be analyzed. Although the structure of asphaltenes is not completely understood, it is an aromatic sheet of 16 fused rings (aroIlatic sl+) with various substituents.
eet).

Typically, when burning crude oils with high asphaltene content, the asphaltenes are not easily combusted, and therefore when this "dirty" crude oil is combusted, they increase the total carbon-containing oil smoke emissions.

According to the invention, the smoke emissions when burning dirty crude oil are significantly reduced compared to burning the same crude oil without the use of an additive cutting composition ladle, in particular in the range of a reduction of about 50-80%. It turns out that it is possible to Similarly, combustion efficiency is significantly improved by using additive compositions. This improvement range can be 0.5% or more depending on the type of crude oil and its composition. Other notable advantages of the invention are:
By using additive compositions, it is possible to actually reduce the amount of excess air required for combustion.
This has the unexpected advantage of using less excess air to achieve reduced NO emissions. this is,
Crude oil can now be effectively combusted in standard oil-fired burner equipment, which is of great importance from an environmental point of view. Another advantage realized by using the additive composition of the present invention is the reduced fouling and corrosion of oil-fired burner equipment that maintains optimal heat transfer; this feature extends the life of the equipment. , reducing maintenance costs and minimizing disruption to plant operations. Other efficiency gains include reduced fan power for sootblower operation, the ability to use lower quality crude oil more effectively, and recovery of marketable ash with lower carbon content. Yet another advantage of using the additive composition in the method of the present invention is that by reducing smoke emissions, there is a corresponding reduction in atmospheric particulates. Particles smaller than 15 microns remain suspended in the atmosphere for long periods of time.
It is well understood that it is inhaled into the body. However, by using the additive composition of the present invention, dark blue particulate oil smoke is significantly reduced from oil combustion equipment.

To test the effectiveness of the additive composition of the present invention and the method of burning crude oil, a pilot plant scale oil-fired furnace was used with suitable equipment to test emissions.
Combustion performance was investigated by analyzing the following emissions in the exhaust gas:

Carbon dioxide (Co), carbon monoxide (CO), oxygen (O
), nitrogen oxides (NOx), sulfur dioxide (S02) and particles (ROx).

Using the following analysis techniques, determine the above emissions in the flue gas? The value of the object was measured. CO and C using non-dispersive infrared analysis
O2 emissions were measured. Oxygen concentration was measured using paramagnetic analysis. No emissions were measured using chemiluminescence analysis. SO₂ emissions were measured using Vals-X fluorometry.

“Performance Standard for New Stationary Pollution Sources”
dSofPerforI1ance for new
Stationary Sources), Federal Register 30, No. 247, 2487 [3 pages (197
The particulate matter was measured and the following characteristics of the particulate matter in the effluent were analyzed using method "5" in December 23, 1999). That is, particle load fl (rar+icujQte IocLc
lihy) Carbon content and ash particle size distribution. The above analytical techniques have uncertainties regarding the analytical values within the following ranges.

C 0 2 25?6 CO ±10% 02 ±10% No ±10% X S02 ±10% Particle Load Summer ±10% Particle Size ±10% Carbon Content ±10% Pilot plant scale furnace requires 26% It operated at an average of 500 KBtu/hour using excess air. Furnace gas outlet temperature is 2075-2225°F (approximately 1135-1
218℃). The combustion air was not preheated in these tests. Based on prior experience, it has been found that there is a fairly close relationship between pilot plant scale oil-fired burners and utility scale oil-fired burners in terms of additive effects on combustion efficiency. In accordance with the present invention, a representative crude oil was obtained for testing in order to investigate the effectiveness of the method of the present invention in improving combustion efficiency and achieving other features and advantages of the present invention. The plant identified as Italian Vega had the following characteristics as shown in Table I.

Table I Heavy oil (Vega) 18,393 Refractory thermal phosphor composition analysis (wt%, dry content) Volatile matter fixed carbon ash elemental analysis (wt%, dry content) Carbon 80.72 Hydrogen 9.07 Nitrogen
0.35 sulfur
2.30 oxygen
7.50 ash content
0.06 Asphaltene content (wt%, dry matter) 15.00 Vanadium (ppnyl amount)
50. Considering the 000.06-like organic carrier, an example carrier was first tested to determine such influence. According to this example, the liquid carrier used was xylene. The additive composition consisted of 5,000 ppII by weight based on crude oil feed and a xylene carrier dispersing it. This composition was diluted before entering the oil-fired furnace to define the required specific iron concentration in the crude oil. Therefore, using xylene with and without ferrocene, the following test results, summarized in Table 3, were obtained. Example 1 Liquid table with the ability to influence the entire combustion process ■ Combustion performance characteristics (Oppn iron) (5ppIl iron)? ■《Volume%》 CO■ (Volume%) Co (Capacity ppm) NO (Capacity ppm) Million BTU) Combustion efficiency 5.0 4.7 13.0 13.3 1? 2.61 Q. 02 0.02 99.43 99.86 5111) Regarding normal performance characteristics of baseline Vega crude oil flame
The t2 and 5x2 effects of the additive composition at an iron equivalent concentration of 1 can be summarized as follows.

1)Although an acceptable concentration of CO remained unchanged in the exhaust gas, carbon or 85C' in the granular ash was very effectively reduced.

2) The fraction of carbon particles has already been changed to an acceptable high (990%) baseline combustion efficiency by about 0.43-6.

3) The ash loading remained virtually unchanged. 4) The average particle size of the particles was reduced very effectively by 50%.

5) No emissions were relatively unchanged, but X this is important from the point of view of achieving reduced excess air requirements.

6) S02 emissions remained relatively unchanged, a rather significant effect To further summarize the results, a list of the above-mentioned properties is shown in Table 3 below.

Table ■ Effect test parameters of additives on combustion of Vega crude oil Test fuel for changes in combustion performance when using additives Crude oil additive concentration (
Iron, ppm) 5CO (content i p11
+1) ONo (capacity 1)
Ill) + 30X SO2 (capacity DI) I1) -40
Ash loading (%) Average particle size of 0 ash (%) - 50 Fine ash (%) Carbon in granular ash (%) - 85 Combustion efficiency (%, absolute) +0.43 As may be noticed, the measurement However, it should be noted that the combustion efficiency confirmed in each table above relates to the combustion efficiency of carbon. Therefore, combustion efficiency can be roughly defined as the extent to which elemental carbon in the fuel is oxidized to CO2. Based on these test results, heavy crude oil with high asphaltene content and low vanadium content, which is difficult to combust, was efficiently combusted to meet typical utility conditions. By increasing combustion efficiency, the amount of thermal energy extracted from crude oil also increased, reducing fuel costs. This means that
This is important because the cost of crude oil is approximately half the cost of the fuel oil normally used in oil-fired burners. By using the additive composition of the present invention, black smoke problems are virtually eliminated. To improve electrostatic precipitator performance and to minimize the above mentioned excess air requirement. In most cases, operators of oil-fired burner installations are unable to reduce the required excess air volume of the boiler during the combustion of heavy oil, since a high amount of particles will appear in the black smoke column. By using the additive composition of the present invention, combustion efficiency can be kept at a high level and the amount of excess air can be reduced. X tests have shown that significantly reducing the amount of excess air will reduce emissions with little change in combustion efficiency. The additive milling of the present invention allows combustion with low excess air and also reduces thermal NOx emissions. The present invention has the added benefit of minimizing corrosion, fouling, fouling and improving overall plant efficiency.
and according to pond emission standards.

Although we have shown the principle of the present invention regarding the combustion of crude oil,
It is appreciated that the principles of the present invention apply equally to the combustion of various other liquid hydrocarbons of the above-mentioned group to reduce NO and emissions. This additive is particularly suitable for use in the treatment of other oils such as heavy and medium oils with a Conradson carbon content greater than 1%. Of course, the above crude oil is 1%
It can be seen that the Conradson number is considerably larger than that of

The effectiveness of the fuel additive according to the invention was also tested with other oils such as those having the following properties outlined in Table IV. Table 1v Benefits Light Heavy oil heat jt (Btu
/Bond, dry smoke content > 18.200 17.300
Viscosity《ll2/sec, 100゜C) 2.2
39 Flash point ('C) 54
65 Ash content (weight%, dry content) (0.001
0.008 Precipitate (wt%, dry matter) <0.1
0.20 Sulfur (wt%, dry content) 0.4
2.40 Conradon Carbon 0.03
18《% by weight, dry matter) Vanadium (pIm, weight <1 100Table 1
The furnace used to test the V oil is the same as that used in Example 1. The furnace is operated at 10% and 26% excess air levels. Furnace gas outlet temperature is 2075-222
The temperature was in the range of 5°F (approximately 1135-1218°C). The combustion air was not preheated. Burning rate is 500κBtu/
It was time. The test time for light oil was 12 hours, while the test time for heavy oil was 6 hours. The results of burning heavy oil and light oil in Table ■ are not shown in Table V and Table Vl below. Table Vl Furnace combustion test results at various concentrations of excess combustion air (10-26%) for light oils pretreated with additives with iron-equivalent concentrations of 02-5 ppm; did. As shown in Table V, heavy oil was tested with the addition of Q, 0.2, 1, and 5 1) Ill in terms of iron in the additive. 0 111) l and 0.2 ppn additives are the same, so 0.2 p
It was found that the amount of PLL additive had no effect on combustion efficiency.

Significant changes were observed in the additive concentrations of tpp1, and even greater differences were observed for the higher concentrations of additives in 51) Ellm. 1 and 5 1) I) At additive concentrations of I1, carbon particles were reduced by 90-97%, with a concomitant improvement in combustion efficiency of 0405-1.6%. Although the average particle size was reduced by 50%, NO emissions increased by only 5X ~ 85 ppIm. However, 1
At the concentration of 131111 and SDI)Ill,
Desired combustion efficiencies of greater than 99% could be achieved with a reduction in excess air volume to 10%. In this case, No
Emissions are 10% excess NO in heavy oil without additives combusted with excess air
It was very close to the value of Therefore, 26X? ≦No in excess air The increase in emissions can be offset by burning heavy oil with additives in 10% excess air without significantly reducing combustion efficiency.

The extent of improvement in the power range and combustion efficiency of carbon particles provided by the additive of the present invention is greater than that of carbonex (Ca) at a low concentration.
rbOneX ), i.e. 1 for lap ppl
pp1 and at low levels of excess air, i.e. 10% versus 26%. The observed reduction in particle size was greater than 1 ppn and was independent of additive content. No appreciable effect on CO or S02 emissions or particle loading was obtained by using the additives of the invention.

The combustion results reported in Table Vl for gas oils show that these results were achieved within the precision of the test and demonstrated that there is little difference between combustion efficiencies at additive concentrations from 0 ppm to 5 ppm. There is. However, the additives affected other parameters.

The additives of the present invention in gas oil affected other performance characteristics of normal combustion of gas oil. Treating gas oil with additive cutting of 0.2 pH and burning with 10% excess air resulted in acceptable carbon particles. reduced the amount by 38% and reduced the allowable particle loading by 33%.
% reduction. CO, NOxx, particle size or 99. 99
The already very high acceptable combustion efficiency of % had no significant effect.

It has been shown that the additives of the present invention have excellent effects on heavy oils and crude oils, these oils having a Conradson carbon content of greater than 1%. However, the additive of the present invention exhibits effects on the combustion of light oil. 1 11
At concentrations below 1111, the additives of the present invention enhance the effectiveness of burning out carbon in the flame of gas oils that are already effectively burning. On the other hand, in heavy oil, the use of additives at concentrations in the range of 1 to 5 pI)lm reduces carbon particles by 90% and increases combustion efficiency by up to 1.6%. This means that
This is a significant improvement in combustion efficiency that results in significant savings in operating power and heat generating plants throughout the year. Similar to crude oil, when the additive of the present invention is used in heavy oil, etc.,
Apart from reducing particulate carbon, it also provides the benefits of eliminating smoke opacity from the furnace, improving electrostatic precipitator performance and minimizing excess air requirements. The reliability and economics of oil burner operation are improved as a result of these secondary effects. By reducing the amount of NO2 emissions by X at the desired combustion efficiency, the additive milling of the present invention further minimizes corrosion and fouling and increases overall gran efficiency.

Although the preferred embodiments of the invention have been described in detail herein, those skilled in the art will recognize that modifications may be made thereto without departing from the spirit of the invention or the scope of the claims.

Claims (1)

[Claims] 1. A method of combusting liquid hydrocarbons having a Conradson carbon content of greater than 1% in a combustion furnace while maintaining NO_x emissions at an acceptable level, the combustion efficiency of said liquid hydrocarbons being increased. a) The following formula ▲ Numerical formula, chemical formula, table, etc. ▼ (wherein R and R' are each independently hydrogen, alkyl, cycloalkyl, aryl, or a heterocyclic group) in a sufficient amount to achieve some degree of improvement. combusting the liquid hydrocarbon in the presence of an additive composition comprising: a) a compound selected from the group consisting of ferrocene and its derivatives; and b) a liquid organic carrier that dissolves the ferrocene; In this case, the amount of excess air required relative to the amount of the liquid hydrocarbons being combusted is adjusted to a low level to maintain the combustion efficiency at an optimum level in the presence of the composition while maintaining the combustion efficiency in the combustible material. reducing NO_x emissions, 1) the amount of NO_x emissions in the combustion product, and 2) the amount of excess air resulting in the same level of combustion efficiency in the absence of the additive composition. A combustion method characterized by less. 2. The combustion method of claim 1, wherein the additive composition is added to the liquid hydrocarbon prior to combustion. 3. The combustion method of claim 1, wherein the liquid hydrocarbon is selected from the group consisting of crude oil, heavy oil, lubricating oil, turbine oil, transformer oil, kerosene, jet fuel, fuel oil, grease, and asphalt. 4. When burning crude oil with a high asphaltene content in the range of 2 to 20% by weight in the oil-fired burner of the combustion furnace, NO
_x emissions while reducing oil smoke emissions while simultaneously reducing excess air required during its combustion, comprising: i) preparing for injection into an oil-fired burner; subjecting the crude oil to a treatment consisting of dilution with the necessary flammable solvent and heating to reduce viscosity; ii) passing said treated crude oil to said oil-fired burner; and iii) combustion in burning said crude oil. A combustion method comprising burning crude oil in said oil-fired burner in the presence of a sufficient amount of said additive composition to improve efficiency to some extent. 5. A sufficient amount of the additive composition is between 0.1 ppm and 100 ppm of iron in the composition based on the amount of liquid hydrocarbon sent to the combustion furnace; A combustion method according to claim 1, 3 or 4, wherein the hydrocarbon has a Conradson carbon content of greater than 1%. 6. The combustion method according to claim 1 or 4, wherein a sufficient amount of the additive composition is 1 ppm to 5 ppm of iron in the composition based on the amount of liquid hydrocarbon sent to the combustion furnace. . 7. The ferrocene compound is dicyclopentadienyl iron, di(methylcyclopentadienyl) iron, di(ethylcyclopentadienyl) iron, methylferrocene, ethylferrocene, n-butylferrocene, dihexylferrocene, phenylferrocene. , m-tolylferrocene, didecylferrocene, dicyclohexylferrocene, and dicyclopentylferrocene. 8. The combustion method according to claim 7, wherein the compound is dicyclopentadienyl iron. 9. The method of claim 8, wherein the organic carrier is selected from the group consisting of high flash point aromatic solvents, aliphatic solvents, and petroleum solvents.