JP2002294258A - Fuel oil additive, combustion aid, and fuel oil composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel oil additive which, at a low temperature, can stably burn particulate matters collected by a diesel particle filter mounted on a diesel engine, thus prolonging the life of the diesel particle filter; a combustion aid containing the same; and a fuel oil composition. SOLUTION: The fuel oil additive, which is added to a fuel oil for a diesel engine equipped with a diesel particle filter, comprises a metal carboxylate. The combustion aid contains the fuel oil additive. The fuel oil composition contains the fuel oil additive and a fuel oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel oil additive,
It relates to a combustion aid and a fuel oil composition. In particular, a fuel oil additive, a combustion aid, and a fuel oil composition for a diesel engine equipped with a diesel particulate filter (hereinafter abbreviated as DPF), more specifically, a particulate matter collected by the DPF (particulate) matte
r, hereinafter abbreviated as PM. ) To improve the flammability of PM
The present invention relates to a fuel oil additive, a combustion aid, and a fuel oil composition for a diesel engine with a DPF, which can stably combust oil at a low temperature, increase the removal efficiency thereof, and extend the life of the DPF. is there.

[0002]

2. Description of the Related Art Diesel engines have been widely used in automobiles, ships, construction machines, generators, and the like because of their high fuel efficiency. However, exhaust gases from diesel engines contain air pollutants such as particulate matter, black smoke, hydrocarbons, and nitrogen oxides, and reduction of these is an urgent need. In particular, PM
Contains a large amount of harmful and carcinogenic substances, causes black smoke, and has a property of easily depositing in the lungs and trachea due to its small particle size. It is a desired substance.

Among these, as a method for reducing black smoke, improvement measures by adding various additives to fuel have been studied. For example, GB-1090289 discloses a method of adding an alkaline earth metal salt of an α-branched monocarboxylic acid as an additive to reduce black smoke.

On the other hand, as a method for removing PM, an efficient and practical DPF has been actively developed. At present, there are several types of DPFs, specifically, (1) alternate regeneration type DPF, and (2) continuous regeneration type D by NO ₂ oxidation method.
PF, (3) continuous regeneration type DPF by catalytic oxidation method,
(4) An intermittent regeneration DPF has been proposed.

The (1) alternating regeneration type DPF is a switching type in which collection and regeneration are alternately performed by using two filter units in which both sides of a silicon carbide fiber non-woven fabric are sandwiched between a wire mesh heater and a protective wire mesh. . However, although this method can cope with the current light oil containing a large amount of sulfur,
A large current is required to burn M, and a dedicated large-capacity generator needs to be mounted, and the filter is damaged by rapid combustion.

[0006] The (2) continuous regeneration type DPF using the NO ₂ oxidation method uses a porous ceramic filter made of cordierite having a wall flow honeycomb structure as a filter, and a NOx is provided by an oxidation catalyst provided on the upstream side thereof.
oxidized x to NO _2, by using a strong oxidizing power of this NO _2, a method for burning PM collected in the filter at low temperatures. However, in this method, the activity of the oxidation catalyst is reduced by the sulfur component in the exhaust gas, and the function of the oxidation catalyst is not sufficiently exhibited. Therefore, it is necessary to reduce the sulfur component in the fuel oil, and it is difficult to adapt to the current light oil. There's a problem.

[0007] The (3) continuous regeneration type DPF by the catalytic oxidation method uses a porous ceramic filter made of a cordierite having a wall flow honeycomb structure coated with two kinds of metal catalysts as a filter, and has no heating device such as a heater. In this method, the PM collected by the filter is burned only by the catalytic action of the metal. In this method, the metal catalyst is relatively insensitive to the sulfur component in the exhaust gas, and thus can be applied to existing diesel oil. However, there is a problem that it is easily affected by phosphorus. In addition, the lower the sulfur component, the higher the performance. Therefore, there is a problem that it is not suitable for a fuel oil having a high sulfur content. Further, there is a problem that it is difficult to apply the method to a vehicle traveling at a low speed for a long time since traveling at an exhaust gas temperature of 300 ° C. or more is required for a certain amount or more.

The (4) intermittent regeneration type DPF uses a porous ceramic filter made of silicon carbide having a wall flow honeycomb structure as a filter, traps PM, and injects fuel during regeneration to increase the temperature of exhaust gas. ,
In this method, hydrocarbons and carbon monoxide are oxidized by an oxidation catalyst, and the temperature is further increased to burn PM.

In any of the above DPFs, industrially,
It is important to effectively exert the function of the DPF and extend its life, and for that purpose, it is necessary to suppress the generation of PM and burn the PM at as low a temperature as possible.

[0010] For this reason, as a method for lowering the combustion temperature of PM, for example, SAE 950396 discloses a method using a cerium compound. International Publication WO 96/34074 discloses an additive comprising a complex of an alkali metal and an alkaline earth metal.

[0011]

SUMMARY OF THE INVENTION However, SAE
In the method of 950396, the effect of lowering the combustion temperature is small, and a relatively large amount must be used in order to obtain a sufficient effect. Therefore, the cerium compound remains after the PM combustion and accumulates in the filter of the DPF.
There is a problem of shortening the life of the device. Also, the method of International Publication WO96 / 34074 has a problem that the effect of lowering the PM combustion temperature is small.

An object of the present invention is to stably burn PM collected by a DPF mounted on a diesel engine equipped with a diesel particulate filter at a low temperature at a low temperature.
An object of the present invention is to provide a fuel oil additive, a combustion aid, and a fuel oil composition that can extend the life of a PF.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to develop an additive for a diesel engine fuel oil with a DPF having the above-mentioned preferable properties, and as a result, a carboxylic acid having a specific structure has been obtained. It has been found that metal salts improve the flammability of PM. The present invention has been completed based on such findings. That is, the fuel oil additive of the present invention is characterized by comprising a salt of a carboxylic acid and a metal.

Specific carboxylic acids constituting the fuel oil additive of the present invention include, for example, 2-methylpentanoic acid, 3-methylpentanoic acid, 4-methylpentanoic acid,
-Ethylhexanoic acid, 4-propylpentanoic acid, 4-ethylpentanoic acid, 2-methyldecanoic acid, 3-methyldecanoic acid, 4-methyldecanoic acid, 5-methyldecanoic acid, 6-
Methyldecanoic acid, 7-methyldecanoic acid, 8-methyldecanoic acid, 9-methyldecanoic acid, 6-ethylnonanoic acid, 5-
Linear branched saturated fatty acids such as propyloctanoic acid, 6-propylnonanoic acid and 2-methyldodecanoic acid, 2-butenoic acid, 3-butenoic acid, 2-pentenoic acid, 3-pentenoic acid,
4-pentenoic acid, 2-hexenoic acid, 3-hexenoic acid, 4
-Hexenoic acid, 5-hexenoic acid, 2-heptenoic acid, 3-
Heptenoic acid, 5-heptenoic acid, 6-heptenoic acid, 2-octenoic acid, 3-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 2-decenoic acid, 4-decenoic acid, 9-decenoic acid, 9-
Hendesenic acid, 10-Hendesenic acid, 2-Dodecenoic acid,
3-dodesenic acid, 5-dodesenic acid, 11-dodesenic acid,
Linear unsaturated fatty acids such as, 2-methacrylic acid, 2-methyl-2-hexenoic acid, 2-methyl-2-heptenoic acid,
3-methyl-2-nonenoic acid, 5-methyl-2-nonenoic acid, 5-methyl-2-hendesenoic acid, 2-methyl-2-
Dodecenoic acid, 5-methyl-2-tridecenoic acid, 2-methyl-9-octadecenoic acid, 2-ethyl-9-octadecenoic acid, 2-propyl-9-octadecenoic acid, 2-methyl-2-icosenoic acid, 2-methyl-2-hexacosenic acid ,
3,4-dimethyl-3-pentaenoic acid, 5,9-dimethyl-2-decaenoic acid, 2,5-dimethyl-2-heptadecaenoic acid, 2,2-dimethyl-11-icosaenoic acid,
Linear branched unsaturated fatty acids such as 2,4-dimethyl-13-n-amyl-2-icosaenoic acid, 2,4,6-trimethyl-2-tetracosaenoic acid, 1-cyclopentanoic acid,
Aromatic carboxylic acids such as cyclohexanecarboxylic acid, cycloheptanecarboxylic acid, 2-phenylbutyric acid, 3-phenylbutyric acid, 4-phenylbutyric acid, 2-phenylpentanoic acid, salicylic acid, acetylsalicylic acid, alkylacetylsalicylic acid, and a single structure As carboxylic acids, carboxylic acids derived from oligomers of propylene and isobutene can also be used.

The carboxylic acid described above may be a naturally occurring one or a synthesized one. As a method for synthesizing a carboxylic acid, various known methods can be employed, for example, the Koch method, the oxo method, and the like. Here, having the function of improving the flammability mainly refers to enabling combustion of particulate matter at low temperatures, specifically, by adding a fuel oil additive to the fuel oil, When it burns,
It refers to lowering the combustion temperature of the generated particulate matter by 50 to 400K.

The carboxylic acid is preferably a monocarboxylic acid. Further, the carboxylic acid is preferably any of a branched and / or cycloaliphatic and an aromatic carboxylic acid. When the carboxylic acid is linear, the solubility of the fuel oil additive is actually reduced when the carboxylic acid is added to a fuel oil or a solvent and used, so that a desired effect may not be obtained. . Therefore,
If the carboxylic acid is a branched and / or cycloaliphatic or aromatic carboxylic acid, the effect of suppressing the burning temperature of PM can be stably obtained.

The carboxylic acid has a constituent carbon number of 2
To 40, more preferably 5 to 17 carbon atoms, and even more preferably 6 to 10 carbon atoms.

If the number of constituent carbon atoms is less than 2, the fat solubility is too low, and the fuel oil additive may not be dissolved in the fuel oil. Solubility may be reduced. If the dissolution in the fuel oil is insufficient, the fuel filter may be blocked.

It is preferable that the carboxylic acid is selected from at least one of 2-ethylhexanoic acid, benzoic acid, salicylic acid, and 4-cyclohexylbutyric acid. According to this, the carboxylic acid is selected from one or more of 2-ethylhexanoic acid, benzoic acid, salicylic acid, and 4-cyclohexylbutyric acid, so that the D mounted on the DPF-equipped diesel engine is increased.
The PM collected by the PF can be stably burned at a low temperature.

Further, the metal is preferably selected from at least one of alkaline earth metals, and more preferably magnesium and / or calcium.

The metal constituting the fuel oil additive of the present invention is an alkaline earth metal. Alkaline earth metals generally include calcium Ca,
Six kinds of strontium Sr, barium Ba, radium Ra, beryllium Be, and magnesium Mg are used as alkaline earth metals. In this fuel oil additive, a carboxylic acid and an alkaline earth metal are combined to form a structure of an alkaline earth metal carboxylate. Being selected from one or more of magnesium and calcium, selected from one or more of the alkaline earth metals,
For example, a calcium salt or a magnesium salt of a carboxylic acid may be used alone, or a mixture of a calcium salt and a magnesium salt of a carboxylic acid may be used.

As the method for synthesizing the alkaline earth metal carboxylate as described above, generally used methods can be adopted, for example, a method of synthesizing a carboxylic acid and a metal oxide, a method of synthesizing a carboxylic acid and a metal hydroxide, And a neutralization method using the same. Incidentally, specific examples of the alkaline earth metal carboxylate in the present invention include magnesium 2,2-dimethylbutyrate.

According to this, by using an alkaline earth metal as the metal, it is possible to improve the effect of reducing the generation of PM when burning the fuel oil while reducing the amount of the additive for the fuel oil. Becomes possible. Further, since the generation of PM trapped by the DPF mounted on the DPF-equipped diesel engine can be reduced, PM does not accumulate in the DPF filter, so that the life of the DPF can be extended. .

The fuel oil additive of the present invention is directly
Add to fuel oil, carboxylic acid type, linear alcohol type, branched alcohol type, linear aldehyde type, branched aldehyde type, ketone type, linear ether type, branched ether type,
Diluents for organic solvents such as cyclic ethers, esters, amines, amides, nitriles, nitros, aromatics, alkylaromatics, heteroaromatics, and nitrogen-containing aromatics, and kerosene oil Any dilution can be added to the fuel oil.

Further, the fuel oil composition of the present invention is characterized by comprising the above-mentioned fuel additive and fuel oil. Here, various hydrocarbon-based fuel oils can be used as the fuel oil, but a gasoline fraction obtained by crude oil distillation or the like, or an intermediate fraction such as light oil or kerosene is preferable. Since these fuel oils are frequently used as fuels for vehicles and the like and are often a PM generation source, the present invention is particularly useful.

Further, the fuel oil composition may contain an antioxidant, a metal deactivator, a microbial disinfectant, an anti-icing agent,
It is prepared by adding additives such as antistatic agent, corrosion inhibitor, defoamer, rust inhibitor, stabilizer, low-temperature fluidity improver, lubricity improver, cetane number improver, colorant, marker, etc. .

According to this, since the fuel oil composition includes the fuel additive and the fuel oil, the fuel additive can lower the combustion temperature of PM generated by burning. Therefore, a fuel oil composition that can extend the life of the DPF can be obtained.

Further, the fuel oil is preferably light oil. Since fuel oil is light oil, light oil is
In particular, the present invention is particularly useful because it is frequently used as a fuel for vehicles and the like and is often a source of PM.

Further, the sulfur content in the fuel oil is 500
ppm or less, more preferably 50 ppm or less. The sulfur content in fuel oil is 500p
If it exceeds pm, the amount of sulfate in the exhaust gas increases, and the effect of suppressing PM emission may be reduced as a whole. Therefore, the sulfur content in the fuel oil is 500 p
If the pressure is equal to or less than pm, the amount of sulfate in the exhaust gas decreases, so that the effect of suppressing PM emission can be increased as a whole.

Further, the combustion aid of the present invention is a combustion aid which is used by spraying it onto a filter of a diesel particulate removing device, wherein the combustion aid contains the above-mentioned fuel additive. Features. The combustion aid of the present invention is DPF
It can also be used directly by spraying it on a filter. Also, when used in this way,
Carboxylic acids, straight-chain alcohols, branched alcohols,
Linear aldehyde, branched aldehyde, ketone, linear ether, branched ether, cyclic ether, ester, amine, amide, nitrile, nitro, aromatic, alkyl aromatic, hetero It is used after being optionally diluted with an organic solvent such as an aromatic or nitrogen-containing aromatic solvent or a diluent such as kerosene oil.

According to this, since the combustion additive contains the fuel additive, the fuel additive can lower the combustion temperature of the PM generated by burning. Has the effect of lowering the PM combustion temperature.

[0032]

The present invention will now be described more specifically with reference to examples and comparative examples. The present invention is not limited to the contents of the embodiment. [Example 1] Addition of fuel oil additive to PM to 200 µm
ol / g, and the combustion temperature of this mixture of PM and the fuel oil additive was measured by differential thermo-thermogravimetry at a rate of 10 ° C./min in air. Table 1 shows the measurement results of the combustion temperature. The PM and fuel oil additives used in the first embodiment are as follows. Additive for fuel oil: Magnesium 2,2-dimethylbutyrate PM: Carbon black (MA100 manufactured by Mitsubishi Chemical Corporation)

Example 2 The fuel oil additive used in Example 2 was different from that of Example 1, but the other conditions were the same as in Example 1. Additive for fuel oil: magnesium 2-ethylhexanoate The combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Example 3 The fuel oil additive used in Example 3 was different from that of Example 1, but the other conditions were the same as in Example 1. Fuel oil additive: magnesium benzoate The combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Example 4 The fuel oil additive used in Example 4 was different from that of Example 1, and the other conditions were the same as those of Example 1. Fuel oil additive: calcium salicylate Further, the combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Embodiment 5 The fuel oil additive used in Embodiment 5 is different from that of Embodiment 1, and other conditions are the same as those of Embodiment 1. Fuel oil additive: magnesium 4-cyclohexyl butyrate Also, the combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Embodiment 6 The fuel oil additives and PM used in Embodiment 6 are different from those in Embodiment 1, but the other conditions are the same as those in Embodiment 1. Fuel oil additive: Magnesium 2-ethylhexanoate PM: PM generated by operating the following diesel engine under the following conditions (called actual PM) Engine specifications Cylinder arrangement: Inline 4-cylinder Combustion method: Direct injection combustion Total displacement: 2488 Compression ratio: 17.5 Engine operating conditions Operating time (hours): 7 Engine speed (rpm): 2400 Load factor (%): 100 Further, the combustion temperature was measured in the same manner as in Example 1. went. Table 1 shows the measurement results of the combustion temperature.

Comparative Example 1 In Comparative Example 1, only carbon black as PM was burned without using a fuel oil additive. Additive for fuel oil: none Further, the combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Comparative Example 2 The same conditions as in Example 1 were used except that the fuel oil additive used in Comparative Example 2 was different from that of Example 1. Fuel oil additive: magnesium oxide The combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Comparative Example 3 The same conditions as in Example 1 were used except that the additive for fuel oil used in Comparative Example 3 was different from that of Example 1. Additive for fuel oil: cerium oxide The combustion temperature was measured in the same manner as in Example 1. Table 1 shows the measurement results of the combustion temperature.

Comparative Example 4 The following PM was burned without using the fuel oil additive used in Comparative Example 4. Additives for fuel oil: None PM: PM generated from the following diesel engines operating under the following conditions (called actual PM) Engine specifications Cylinder arrangement: In-line 4-cylinder Combustion method: Direct injection combustion Total displacement: 2488 Compression ratio: 17.5 Engine operating conditions Operating time (hours): 7 Engine speed (rpm): 2400 Load factor (%): 100 Further, as in Example 1, the combustion temperature was measured. Table 1 shows the measurement results of the combustion temperature.

[0042]

[Table 1]

As is clear from Table 1, the combustion temperatures of Examples 1 to 5 are lower than those of Examples 1 to 6 and Comparative Examples 1 to 4. In the above embodiment, P
The fuel oil additive according to the present invention was added to M.
The present invention is not limited to this, and the PM may be burned by spraying the combustion aid on the filter of the DPF. Also in this case, similarly to the case where the fuel oil additive is added,
The effect of lowering the PM combustion temperature is obtained.

[0044]

According to the present invention, the fuel oil additive can suppress the burning temperature of PM by the metal carboxylate having a specific structure assisting PM.
Further, since PM can be stably burned at a low temperature, the DPF is used under a relatively low temperature condition, so that the life of the DPF can be extended.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H013 CE02 CJ03 CJ14 4H015 AA22 AA25 AB05 BA05

Claims (15)

[Claims] 1. A fuel oil additive added to a diesel engine fuel oil equipped with a diesel particulate removing device, wherein the fuel oil additive comprises a salt of a carboxylic acid and a metal. Additive for oil. 2. The fuel oil additive according to claim 1, wherein the fuel oil additive is added to the fuel oil, and the combustion temperature of the particulate matter generated when the fuel oil is burned is 50 to 400.
A fuel oil additive characterized by lowering K. 3. The fuel oil additive according to claim 1, wherein the metal is selected from at least one of alkaline earth metals. 4. The additive for fuel oil according to claim 3, wherein the metal is magnesium and / or calcium. 5. The additive for fuel oil according to claim 1, wherein the carboxylic acid is a monocarboxylic acid. 6. The additive for fuel oil according to claim 1, wherein the carboxylic acid is a branched and / or cycloaliphatic,
An additive for fuel oil, which is any one of aromatic carboxylic acids. 7. The additive for fuel oil according to claim 1, wherein the carboxylic acid has 2 to 40 carbon atoms. 8. The additive for a fuel oil according to claim 7, wherein the carboxylic acid has 5 to 17 carbon atoms. 9. The fuel oil additive according to claim 8, wherein the carboxylic acid has 6 to 10 carbon atoms. 10. The fuel oil additive according to claim 1, wherein the carboxylic acid is 2-ethylhexanoic acid, benzoic acid,
A fuel oil additive selected from at least one of salicylic acid and 4-cyclohexylbutyric acid. 11. A combustion aid used by spraying on a filter of a diesel particulate removing device, wherein the combustion aid contains the fuel additive according to any one of claims 1 to 10. A combustion aid characterized by becoming. 12. A fuel oil composition comprising the fuel additive according to claim 1 and a fuel oil. 13. The fuel oil composition according to claim 12, wherein the fuel oil is light oil. 14. The fuel oil composition according to claim 12, wherein a sulfur content of the fuel oil is 500 ppm or less. 15. The fuel oil composition according to claim 14, wherein the fuel oil has a sulfur content of 50 ppm or less.