Cetane improver

Cetane improvers are fuel additives used to improve the cetane index in diesel fuel. Generally, producing high cetane number diesel requires a high volume of heavy crude petroleum. Therefore, when the crude oil contains a low proportion of heavy crude petroleum, the refiners add cetane improvers.

The most commonly used cetane improver is 2-ethylhexyl nitrate (2-EHN). However, this additive tends to increase diesel nitrogen content. This results in more nitrogen oxide emission in exhaust gas.