Marine Engineering

Nitrogen oxides are the major air pollutants and pose a challenge to engine manufacturers to meet the limits set forth by the MARPOL Annex VI.  Combustion of fuels is the primary anthropogenic source of formation of nitrogen oxides, While Nitric oxide (NO) and nitrogendi-oxide are usually grouped together as NOx emissions, nitric oxide is the predominant oxide of nitrogen produced by combustion process. Therefore, it is an important minor species in the combustion because of its contribution to air pollution.  The principal source of NO is the oxidation of atmospheric (molecular) nitrogen. However, if the fuel contains  significant  nitrogen, the oxidation of the fuel nitrogen-containing compounds  is an additional source.  In the combustion of fuel that contains  no nitrogen , nitric oxide is formed by  three chemical mechanisms  that involve nitrogen from the air.  The  three principal mechanisms are: i) The th...