JPH0834982A - Fuel additive for spark ignition engine and fuel containing the same additive - Google Patents

Abstract

PURPOSE:To provide a fuel additive for spark ignition engine, capable of uniformly dissolving nitromethane in gasoline without causing phase separation and a fuel for spark ingnition engine capable of producing a high output power at a low fuel cost. CONSTITUTION:This fuel additive is composed of 30 to 90vol.% nitromethane, 1 to 30vol.% methanol, 1 to 30vol.% butanol and 2 to 45vol% ether or ketone. The fuel for spark ignition engine is prepared by blending 5 to 50vol.% this fuel additive with 95 to 50vol.% gasoline.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fuel additive for a spark ignition engine and a fuel using the additive. More specifically, the present invention provides an additive that can be added to a gasoline-based fuel, has no phase separation even at low temperatures such as in cold regions, and can provide high output and low fuel consumption, and the additive. Regarding the fuel used.

[0002]

2. Description of the Related Art Conventionally, glow plug type engines have been mainly used as a small model engine, and the fuel used for them has methanol as a main component and nitromethane of 10 to 30% by volume and a lubricant base. Many of the added high-performance products are used. In recent years, model airplanes and helicopters are becoming more widely used not only as hobbies but also for pesticide spraying and aerial video shooting, and the engine is often a spark ignition type of about 30 to 250cc, which is larger than the glow plug type. It is being appreciated. The fuel used for this spark ignition engine is normal premium gasoline or regular gasoline, but general users demand improved output during takeoff, sharp turns, and sudden rises, and extended flight time per refueling. ing. Therefore, there is a demand for fuel for a spark ignition engine that has high output and low fuel consumption.

[0003]

SUMMARY OF THE INVENTION The present invention is directed to a fuel additive which provides a fuel for a high output and low fuel consumption spark ignition engine with improved combustibility, and a high output and low fuel consumption spark ignition engine using the same. The purpose was to provide fuel for use.

[0004]

As a result of intensive studies to solve the above-mentioned problems, the present inventors improved the output by blending nitromethane and a specific alcohol in a gasoline-based fuel. Further, they have found that the compatibility of gasoline and nitromethane is improved by blending ether or ketone, and the present invention has been completed based on the finding. That is, the present invention provides (1) a fuel additive comprising 30 to 90% by volume of nitromethane, 1 to 30% by volume of methanol, 1 to 30% by volume of butanol, and 2 to 45% by volume of ether or ketone,
(2) Fuel for spark ignition engine, which is prepared by blending 5 to 50% by volume of the fuel additive described in (1) and 95 to 50% by volume of gasoline, and (3) Using gasoline as a base fuel to improve combustibility. 1 to 30% by volume of nitromethane as an agent, 0.1 to 10% by volume of methanol as a compatibilizer, 0.1 to 10% by volume of butanol, and 0.3 to 1.5% by volume of an ether or a ketone as much as a blending amount of nitromethane. A fuel for a spark ignition engine, which contains the amount of

Nitromethane to be added to the fuel additive for a spark ignition engine of the present invention is prepared by boiling methyl p-toluenesulfonate with sodium nitrite, heating chloroacetic acid and sodium nitrite, and lower paraffins with nitric acid and sulfuric acid. It can be produced by a method such as nitration using a mixture of, followed by fractional distillation. The blending amount of nitromethane in the fuel additive for spark ignition engine is 30 to 9
It is 0% by volume, preferably 60 to 80% by volume. If the blending amount of nitromethane is less than 30% by volume, the amount of compatibilizer increases, and a large amount of addition is required to improve the output, but in reality, the theoretical air-fuel ratio greatly changes and much fuel is used in the engine. Since fuel must be supplied, fuel efficiency is deteriorated, which is not preferable. When the blending amount of nitromethane exceeds 90% by volume, the amount of the compatibilizing agent becomes small and nitromethane may be separated at low temperature, which is not preferable. The fuel additive for a spark ignition engine of the present invention contains 1 to 3 methanol.
0% by volume, preferably 5 to 20% by volume is blended. When the blending amount of methanol is less than 1% by volume, nitromethane may cause phase separation in gasoline at low temperatures, which is not preferable. Even if the blending amount of methanol exceeds 30% by volume, the effect of compatibilizing nitromethane with gasoline does not improve in proportion to the blending amount, but rather the output of the fuel blended with the additive decreases, or the methanol is in gasoline It is not preferable because it may absorb moisture and cause phase separation. The fuel additive for a spark ignition engine of the present invention contains 1 to 30% by volume, preferably 5 to 15% by volume of butanol. As butanol to be blended, n-butanol,
Either 2-butanol, isobutanol or t-butanol can be used, and also mixtures of these. If the content of butanol in the fuel additive for a spark ignition engine is less than 1% by volume, nitromethane may cause phase separation in gasoline at low temperatures, which is not preferable. Even if the blending amount of butanol exceeds 30% by volume, the effect of compatibilizing nitromethane with gasoline and the effect of improving the output do not improve in proportion to the blending amount, which is not preferable. The fuel additive for a spark ignition engine of the present invention contains 2 parts of ether or ketone.
˜45% by volume, preferably 5-40% by volume.
Examples of the blended ether include diethyl ether, methyl-t-butyl ether, diisopropyl ether, di-n-butyl ether, methyl-t-amyl ether, isopropyl-t-butyl ether, sec-
Butyl-t-butyl ether, methyl-1,1,2-trimethylpropyl ether, methyl-1,1-dimethylbutyl ether and other aliphatic ethers, tetrahydrofuran, dioxane and other cyclic aliphatic ethers, anisole, diphenyl ether and other fragrances Examples thereof include group ethers. In addition, examples of the blended ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl-t-butyl ketone, diisopropyl ketone, di-n-butyl ketone, methyl-t-amyl ketone, isopropyl-t-butyl ketone, sec-butyl-t. -Butyl ketone, methyl-1,1,2-trimethylpropyl ketone, methyl-1,1-dimethylbutyl ketone and other aliphatic ketones, cyclohexanone, tetrahydro-p-benzoquinone and other cyclic aliphatic ketones, acetophenone, benzophenone, etc. The aromatic ketones can be mentioned. These ethers or ketones can be blended alone or in a mixture of two or more kinds. If the amount of ether or ketone to be added to the fuel additive for spark ignition engine is less than 2% by volume, nitromethane may cause phase separation in gasoline at low temperatures, which is not preferable. Even if the blending amount of ether or ketone exceeds 45% by volume, the effect of compatibilizing nitromethane with gasoline does not improve in proportion to the blending amount, which is not preferable. The ether used in the fuel additive for a spark ignition engine of the present invention has a higher effect of increasing the fuel output as its boiling point and flash point are lower. This is probably because the lower the boiling point and the flash point, the faster the vaporization in the compression step and the better the mixing with air. The nitromethane used as the fuel additive for the spark ignition engine of the present invention acts as a power booster and increases the explosive power, but nitromethane does not have the effect of increasing the octane number, but rather lowers the octane number. When an aromatic compound such as toluene is added to prevent a decrease in octane number, the output is decreased, which is not preferable. On the other hand, by using ethers having a high octane number such as methyl-t-butyl ether as the ethers used in the fuel additive for a spark ignition engine of the present invention, fuel economy and octane number can be improved.

The fuel for a spark ignition engine of the present invention comprises 5 to 50% by weight of nitromethane, 1 to 30% by volume of methanol, 1 to 30% by volume of butanol, and 2 to 45% by volume of ether or ketone. It is a mixture of 95% by volume and 95-50% by volume of gasoline. When the blending amount of the fuel additive is less than 5% by volume, the effect of improving the fuel output is not sufficient, which is not preferable. If the blending amount of the fuel additive exceeds 50% by volume, it is not suitable as a fuel for a normal spark ignition engine, which is not preferable. However, by changing the design of the spark ignition engine, it is possible to use a fuel in which the blending amount of the fuel additive exceeds 50% by volume and to obtain an ultra high power engine. The gasoline used as the fuel for the spark ignition engine of the present invention is not particularly limited, and light straight-run gasoline,
Catalytically reformed gasoline, catalytically cracked gasoline, alkylate gasoline, isomerized gasoline, hydrocracked gasoline and the like can be used. These are usually made into gasoline having desired properties by proper blending, but they can be used alone. Methanol and butanol are blended in the fuel additive for a spark ignition engine of the present invention, and these alcohols may cause an azeotropic phenomenon with the components of gasoline and volatility may become extremely high. Pay attention to the above and select the gasoline to be blended. In addition, generally, premium gasoline has a greater compatibility with nitromethane than regular gasoline, and the fuel additive for a spark ignition engine of the present invention is selected in consideration of the properties of gasoline to be compounded. The fuel obtained by blending the fuel additive for spark ignition engine of the present invention with premium gasoline exhibits excellent performance as gasoline for spark ignition engine. Further, since the fuel additive for a spark ignition engine of the present invention can be added to regular gasoline, its versatility is significantly increased. In the fuel for the spark ignition engine of the present invention,
Gasoline is blended with a fuel additive consisting of nitromethane, methanol, butanol and ether or ketone. The ether or ketone acts as a compatibilizing agent to prevent nitromethane from mixing uniformly in gasoline and causing separation, and the blending amount of the ether or ketone is 0.3 to 1.5 times by volume, preferably the blending amount of nitromethane. It is 0.5 to 1.0 times the capacity. If the blending amount of the ether or ketone is less than 0.3 volume times the blending amount of nitromethane, the nitromethane causes phase separation at low temperature, which is not preferable. Even if the blending amount of ether or ketone exceeds 1.5 volume times of the blending amount of nitromethane, the effect of compatibilizing nitromethane with gasoline does not improve in proportion to the blending amount, which is not preferable. The fuel for a spark ignition engine of the present invention can be produced by previously blending a fuel additive consisting of nitromethane, methanol, butanol and ether or ketone, and then adding the gasoline. It can also be produced by sequentially adding and mixing nitromethane, methanol, butanol and ether or ketone to gasoline.
The compounding order of nitromethane, methanol, butanol and ether or ketone is not particularly limited, and they can be added in any order. Depending on the order of addition,
In the course of blending, the blended components may not be uniformly mixed with gasoline to cause phase separation, but if all components are blended and stirred, a uniform fuel is obtained.

[0007]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Examples 1-12 and Comparative Examples 1-3 Regular gasoline, premium gasoline and light FC
The state of phase separation at low temperature was investigated for the composition in which C or naphtha was mixed with nitromethane, methanol, and butanol, and the composition with or without ether or ketone. Gasoline or light FCC naphtha, nitromethane, methanol, butanol and ether or ketone were blended according to the formulation shown in Table 1, put in a 500-ml measuring cylinder, and kept in a low temperature constant temperature bath set to a predetermined temperature for 24 hours. After maintaining, the volume% of the phase-separated portion was calculated. The formulations of Examples 1-12 and Comparative Example 2 were all homogeneous liquids at room temperature and could be cast into a 500-ml graduated cylinder. Since the formulations of Comparative Examples 1 and 3 were separated even at room temperature, each component was put in a graduated cylinder with a 500-ml stopper together at a predetermined ratio and vigorously shaken. Then, the graduated cylinder was placed in a low temperature constant temperature bath. I put it in. Table 2 shows the state of phase separation after 24 hours.

[0008]

[Table 1]

[0009]

[Table 2]

[0010]

[Table 3]

[0011]

[Table 4]

Examples 1 to 3 using regular gasoline
Comparing 5 and Comparative Example 1, the formulation of Comparative Example 1 containing no ether or ketone was already phase-separated even at room temperature, and the state did not change even when cooled to -20 ° C. On the other hand, the formulations of Examples 4 and 5 in which dioxane or methyl ethyl ketone was blended did not cause phase separation even at −20 ° C. and maintained a uniform state. Further, the formulations of Examples 1, 2 and 3 in which diethyl ether, diisopropyl ether or methyl-t-butyl ether was blended, phase-separated at -20 ° C, but 0 ° C or -5.
It is uniform at 0 ° C, and it can be seen that these compounds have practicality as compatibilizers. Comparing Examples 6 to 11 and Comparative Example 2 using premium gasoline,
It can be seen that the blend of Comparative Example 2 containing no ether or ketone maintains a uniform state at room temperature and starts phase separation when cooled to 0 ° C., and premium gasoline has a higher solubility in nitromethane as compared with regular gasoline. . However, when premium gasoline blended with nitromethane is cooled to 0 ° C or lower, the amount of phase separation rapidly increases. On the other hand, diethyl ether, diisopropyl ether, methyl-t-butyl ether,
The blends of Examples 6, 7, 9, 10 and 11 in which dioxane or methyl ethyl ketone was blended did not cause phase separation even at -20 ° C and maintained a uniform state. Also,
The compound of Example 8 containing di-n-butyl ether was phase-separated at −20 ° C., but was uniform at 0 ° C., and di-n-butyl ether was also useful as a compatibilizer. I understand. Comparing Example 12 and Comparative Example 3 using light FCC naphtha, the formulation of Comparative Example 3 without ether or ketone was already phase separated even at room temperature and the state was cooled to -20 ° C. Did not change either. On the other hand, it can be seen that the formulation of Example 12 in which methyl-t-butyl ether is blended has little effect of phase separation and has an effect of compatibilizing nitromethane with methyl-t-butyl ether. Examples 13 and 14 and Comparative Examples 4 and 5 Engines were used to compare the maximum number of revolutions due to propeller load. The engine used is a 2-cycle gasoline engine with a displacement of 124cc and the maximum pressure is 10PS / 8500rpm.
Is. The results are shown in Table 3.

[0013]

[Table 5]

The engine speed was 6520 rpm when premium gasoline was used and the engine speed was 7130 rpm when regular gasoline was used, while the composition of Example 3 and the composition of Example 9 were used. In both Example 13 and Example 14, the engine speed was over 8000 rpm, and it can be seen that the addition of nitromethane has the effect of increasing the output. In addition, when the engine is operated in the same condition as when nitromethane is not added, the output is improved and fuel is saved.

[0015]

EFFECTS OF THE INVENTION By using the fuel additive for a spark ignition engine of the present invention, it becomes possible to dissolve nitromethane in gasoline uniformly without causing phase separation, and nitromethane produces a high-power and fuel-efficient spark. Fuel for the ignition engine can be obtained.

Claims (2)

[Claims] 1. A fuel additive comprising 30-90% by volume nitromethane, 1-30% by volume methanol, 1-30% by volume butanol and 2-45% by volume ether or ketone. 2. The fuel additive according to claim 1, 5 to 50% by volume.
And a fuel for a spark ignition engine containing 95 to 50% by volume of gasoline.