What is NOx?: NOx is the generic term for a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts. Many of the nitrogen oxides are colorless and odorless. However, one common pollutant, nitrogen dioxide (NO2) along with particles in the air can often be seen as a reddish-brown layer over many urban areas.

Nitrogen oxides (NOX) formed during the combustion of coal are mainly nitric oxide (NO) and nitrogen dioxide (NO2), together commonly referred to as NOX. NOX formed during combustion is composed predominantly of NO (90-95%) and a lesser amount (5-10%) of NO2. A very small percentage of nitrous oxides (N2O) are also formed . The nitric oxide slowly oxidizes to nitrogen oxide in the atmosphere. However this reaction is accelerated in the presence of ozone (O3) and reactive organic compounds. Source

The main source of NOx emissions is the combustion of fuels in motor vehicles, residential and commercial furnaces, industrial and electrical-utility boilers and engines, and other equipment. Source

Links

NOx emissions and biodiesel: Nitrogen oxide emissions with biodiesel, taken from various scientific and industry studies.

Technologies for Control of NOx Emission

ISA | Monitoring NOx emissions