NOx

Nitrogen oxides (NOx) is a general term for toxic gas molecules that are chemical compounds between nitrogen and oxygen, and is an essential component of air pollution. Did you know that the oxidation process started by ozone can actually reduce environmentally harmful industrial emissions? By using ozone in the right way, you can, for example, get a sharp reduction in both NOx emissions and consumption of urea. This is good for the environment, the industrial economy as well as people and animals in the local environment.

Nitrogen oxides (NOx)

Nitrogen oxides (NOx) is a common term for nitrogen oxides N2O, NO, N2O3, NO2 and NO3 and is a chemical compound of oxygen and nitrogen that is formed during the combustion of fuel and organic material at high temperatures. NOx emissions in Norway mainly come from energy production from oil and gas, land-based industry, road traffic and shipping.

NOx can be spread over longer distances if it reaches the troposphere within approx. 1 day and is thus not only a local and regional problem, but can be transported across continents with a duration of approx. 5–10 days.

NOx can:

• react with ammonium (NH4+), water vapor and other compounds and form nitric acid (HNO3). Inhalation of nitric acid vapor is toxic and can lead to catarrh of the bronchi, pneumonia and etching of the alveoli.
• react with volatile organic compounds in the presence of sunlight and form ground-level ozone which damages vegetation by reacting with unsaturated fats in cell membranes, and can give rise to hydrogen peroxide which causes oxidative stress.
• contribute to acid rain with a lower pH value than 5.6. Acid precipitation has the greatest consequences for waterways, forests and buildings. An example is fish death due to disturbances in the water and ion balance and respiratory failure.
• form smog or yellow clouds that cover major cities and cause poor air quality. NOx can cause serious health damage in humans, including asthma and respiratory infections.

How does it work?

NOx reduction with ozone is nothing more than an oxidation process in several stages.

The reaction happens very quickly and with each step the NO form becomes more and more easily soluble. Eventually it is easy to dissolve in, for example, water, and separate from the exhaust in, for example, a scrubber.