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Why higher cetane number is not suitable for diesel engine?
Cetane number is an inverse function of a fuel’s ignition delay, the time period between the start of ignition and the first identifiable pressure increase during combustion of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower Cetane fuels.
What is the biggest difference between diesel fuel and gasoline?
While both gasoline and diesel start as crude oil mined from the earth, the refining process then separates them into various types of fuels. Diesel fuel is thicker than gasoline, which means it evaporates slower. Diesel fuel also has more energy density.
How does cetane number increase in diesel?
Innospec can also provide a nitrogen-free Cetane Number Improver, CI-0808. This additive can be used to increase the Cetane Number of diesel fuels without increasing the fuel nitrogen content. CI-0808 is a blend of Di-tert-butyl peroxide in solvent and is typically used at 0.05\% to 0.50\% volume.
Why is diesel not flammable?
The range of flashpoints is due to there being a few different types of diesel fuel (1,2,3,4). The number that is most commonly used as the flashpoint of diesel is 140 degrees Fahrenheit or 60 degrees Celsius. Because the flashpoint of diesel is above 199.4 degrees Fahrenheit, it is classified as a flammable liquid.
Why cetane number is important to the fuel?
Why do cetane numbers matter? The higher a fuel’s cetane number, the quicker it ignites — and that carries a variety of benefits for diesel equipment. From increased fuel economy to fewer emissions to better power output, fast combustion is key to a diesel engine’s performance.
What does the cetane number of diesel indicate?
The cetane number (CN) is an indicator of the ignitibility of diesel fuels. It provides information about the ignition delay, i.e. the speed of self-ignition of diesel fuel when injected into hot air through the fuel injector. This leads to the typical loud diesel combustion noise (“knocking”).
Why is diesel more than gas?
The federal excise tax for on-highway diesel fuel of 24.3 cents per gallon is 6 cents per gallon higher than the federal excise tax on gasoline. …
Is diesel heavier than gas?
Diesel fuel is heavier than gasoline (larger molecules). Diesel fuel maintains a different density and viscosity than gasoline. Diesel fuel has a lower autoignition temperature than gasoline.
What is cetane number of diesel?
The scale for measuring cetane ranges from 0 to 100, and the higher the number, the better. Modern highway diesel engines tend to require fuel with a cetane number ranging from 45 to 55. Typically, regular no. 2 diesel has a cetane number of 40 to 42, while Cenex® Premium Diesel has a cetane number of 47 to 52.
How can cetane number be increased?
The cetane number of a middle distillate fuel fraction is increased by contacting said fraction with oxygen or oxidant, in the presence of a catalyst, for a time sufficient to increase the cetane number. The catalyst selectively oxidizes benzylic carbon atoms present in the fuel to ketones.
Why is gasoline more flammable than diesel?
Both diesel and gasoline are highly flammable. But gasoline vapourises much more readily than diesel at room temperatures, and VAPOUR burns, not the liquid fuel. So gasoline is much easier to ignite at room temperatures.
Are diesel engines more fuel efficient than gasoline?
Diesel engines are generally more fuel efficient because diesel is thicker than gasoline, which means it’s more energy-dense. Diesel combustion emits less carbon dioxide and carbon monoxide than gasoline combustion, but it also emits more particulate matter.
What is the difference between cetane and Octane in gasoline?
Cetane doesn’t really apply to gasoline. Cetane is for diesel, octane for gasoline. The reason for that is because diesel engines (unlike gasoline engines) don’t compress the fuel, just the air. Fuel is then injected into the chamber to detonate upon contact.
What is the difference between crude oil and diesel fuel?
Crude oil can be refined into different fuels with different consistencies. Diesel fuel is refined to a thicker, more oily consistency, while gasoline is refined to a lighter consistency. Gasoline is also more flammable than diesel, and requires less heat for combustion.