Fuel for internal combustion engine

Abstract

A fuel for an internal combustion engine is provided which is environment friendly and arranged to minimize corrosion of the internal combustion engine. The fuel is characterized by 50 to 75 percent by weight of an alcohol component including isopropyl alcohol, isobutyl alcohol, and n-butyl alcohol and 25 to 49.9 percent by weight of a hydrocarbon component, wherein the ignition point is not higher than −20° C. Preferably, the alcohol component is 50 to 60 percent by weight while the hydrocarbon component is 40 to 49.9 percent by weight. Also, the alcohol component contains 15 to 30 percent by weight of isopropyl alcohol, 15 to 25 percent by weight of isobutyl alcohol, and 7 to 20 percent by weight of n-butyl alcohol.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a fuel for an internal combustion engine and particularly, to a type of fuel for an internal combustion engine which is environment friendly and can produce a minimum of pollution. BACKGROUND OF THE INVENTION [0002] Most common fuel for an internal combustion engine used, for example, in an automobile is gasoline. Gasoline or petroleum fuel when burned in the engine generates unwanted fumes including COx (carbon oxide), NOx (nitrogen oxide), and SOx (sulfur oxide) which are discharged together as exhaust gas into the air thus causing air pollution. [0003] For replacement, a variety of alcohol based fuels for internal combustion engines have been proposed which contain large concentrations of alcohols. One of those alcohol based fuels is known as disclosed in Japanese Patent Laid-open Publication (Heisei) 9-227880. The known alcohol based fuel contains 48 to 58 percent by weight of alcohol such as methyl or isobutyl alcoh...

AI Technical Summary

Benefits of technology

[0007] The alcohol component at 50 to 75 percent by weight comprises isopropyl alcohol, isobutyl alcohol, and n-butyl alcohol. As isopropyl alcohol, isobutyl alcohol, and n-butyl alcohol are greater in the number of carbons (C) than methyl alcohol or ethyl alcohol, their corrosive effect on aluminum is lower thus minimizing corrosion of the internal combustion engine. When the alcohol component is lower than 50 percent by weight, it is overwhelmed by the hydrocarbon component. This will accelerate the generation of NOx and COx at the combustion thus increasing NOx and COx in the exhaust gas and polluting the environment. When the alcohol component exceeds 75 percent by weight, it disturbs the generation of thermal energy at the combustion hence declining the output power of the internal combustion engine and the performance of an automobile. Since the ignition point of the fuel is not higher than −20° C., the low temperature startup can be ensured at a desired temperature.

[0010] As its alcohol component contains 15 to 30 percent by weight of isopropyl alcohol, 15 to 25 percent by weight of isobutyl alcohol, and 7 to 20 percent by weight of n-butyl alcohol, the fuel according to the present invention can remain stable at the concentration of alcohols thus ensuring improved characteristics for the driving performance and the acceleration. Preferably, the weight ratio between isopropyl alcohol, isobutyl alcohol, and n-butyl alcohol is expressed by (1.8-2.2):(1.3-1.7):1. This allows the fuel to be favorably used for energizing an automobile.

[0012] As the fuel contains not higher than 6.0 percent by weight of MTBE (methyl tertiary butyl ether), it can produce less amounts of hazardous matters thus being environment friendly. The smaller the amount of MTBE, the more the fuel will be environment friendly. Preferably, MTBE may be 0.3 percent by weight or lower.

[0013] The hydrocarbon component in the fuel of the present invention may contain 0.2 to 1.0 percent by weight of aromatic substances and 48.9 to 49.7 percent by weight of non-aromatic substances. With its hydrocarbon component doped at the above-mentioned percentage, the fuel can provide characteristics essential as an automobile fuel even when the amount of its alcohol component is higher.

Problems solved by technology

This will accelerate the generation of NOx and COx at the combustion thus increasing NOx and COx in the exhaust gas and polluting the environment.

When the alcohol component exceeds 75 percent by weight, it disturbs the generation of thermal energy at the combustion hence declining the output power of the internal combustion engine and the performance of an automobile.