What Is the Cetane Index?

Cetane number is an important indicator for measuring the ignition performance of diesel in compression ignition engines. The higher the cetane number indicates that the diesel has good ignition performance, short flame retardation period, uniform combustion, and stable engine starting. A low cetane number indicates that the combustion is difficult, the flame retardation period is long, and the engine is in a rough state. However, if the cetane number is too high, a small amount of black smoke will be generated due to partial incomplete combustion.

And petrol

Cetane number of diesel oil and its chemical composition and

The cetane number of diesel is determined under standard operating conditions by comparing the ignition properties with the ignition properties of a standard fuel with a known cetane number. The method is to adjust the engine

Cetane number improver is a kind of oil additive which can be added to diesel oil, which can increase the cetane number of diesel oil and has little influence on other oil properties. ^[3]

Cetane number

There are many types of cetane number improvers. The main types of cetane number improvers are nitrate compounds, organic peroxides, organic sulfur compounds, dinitro compounds, ethers, and fatty acid derivatives. ^[3]

Cetane number performance

Properly adding a cetane number improver can increase the cetane number of diesel oil, but different oil components have different sensitivities to additives. And the sensitivity of various diesel fuels to the cetane number improver does not have a linear relationship, but when the added amount reaches a certain level, the sensitivity gradually approaches zero. Adding additives to diesel oil can affect the flash point of diesel oil, and the diesel oil after improving agent will decay after storage for a period of time. Therefore, it is recommended that when using cetane number improver to blend oil products, the cetane number should be above 46 and the storage period should be minimized. ^[4]

Cetane number development trend

With the increase in requirements for locomotive fuel oil and the constraints on the economic benefits of existing fuel oils, the market has an urgent need for new, safe and good economic benefits cetane number improvers. Generally speaking, compared with diesel, cetane number improver has lower viscosity, lower freezing point and close flash point. In selecting a cetane number improver, in addition to improving the cetane number of diesel oil, it must also have good stability. In addition, there are other factors to consider, such as highly corrosive to metals and compatibility with diesel, these factors are very important for selecting the proper cetane number modifier group. ^[4]