Q & A > Question Details
Why do Olefins have a higher Cetane Number than I-Paraffins?
30/12/2012 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
Diesel fuel as such is a mixture of hydrocarbons of various proportions. The hydrocarbon composition of Diesel fuel changes as per crude processing, secondary treating processing and blending . Cetane number of a fuel depends upon ignition quality of the fuel i.e.autoignition temperature. Isoparaffin hydrocarbons generally have higher autoignition temperature and olefinic hydrocarbons has lower autoignition temperature. Hence Olefins has a higher Cetane Number compared to I-Paraffins.
01/10/2012 A: keith bowers, B and B Consulting, kebowers47@gmail.com
CETANE Number is a measure of 'ignition delay'--how long it takes after the start of fuel injection for the fuel to begin burning. shorter is better--smoother operation,less knocking, less smoke, more power, better fuel economy.
iso paraffins are much easier to ignite (autoignition temperatures about 400F, while 'olefins' require much higher temperatures to auto-ignite.