NOx Reduction

Nitrogen oxides or NOx are chemical oxides that are produced during combustion at high temperatures. The two elements, nitrogen and oxygen typically do not react with each other at normal temperatures, but when high temperature combustion occurs, the elements combine to form this toxic oxide. The release of these toxins into the atmosphere is considered major contributors to air pollution, and for industries and manufacturers of internal combustion engines, NOx reduction is now a legal necessity.

Besides being a single toxin, NOx combines with other substances and creates smog when it is exposed to sunlight. This creates a major health hazard for people that live in affected areas. NOx penetrates into the lung tissue and can cause permanent damage to lung tissue. Children, the elderly, people with asthma and other breathing difficulties, and people that work outside are especially susceptible to the negative health effects of NOx. The way to reduce that health risk is for companies to employ NOx reduction measures.

Nitrogen oxides also combine with water which produces nitric acid. When released from the atmosphere it is called acid rain, and results in significant long term damage to any structure that is repeatedly exposed to it.

In 1997 the Kyoto Protocol classified NOx as a greenhouse gas, and also called for a world wide effort to reduce the amount that was being released into the atmosphere. In the United States this is regulated by the Environmental Protection Agency (EPA). They have set levels which can legally be released by companies. If the company does not comply with the regulations they can have sanctions and significant fines leveled against them.

Many industrial and utility operations are using a selective catalytic reduction or SCR method for removing nitrogen oxides from the atmosphere. SCR uses an ammonia based reductant that combines with the NOx and is absorbed by a catalyst. Once it is in the catalyst a chemical reaction takes place to separate the nitrogen and oxygen. The result is that instead of NOx, these operations are now releasing Nitrogen and Water into the atmosphere, both of which are harmless.

Using modern selective catalytic reduction methods it is now possible to remove 70 to 95% of the nitrogen oxides that are released into the environment. The amount that is removed really depends on the SCR method that is used and the type of operation it is used with.

Industries and manufacturers are now very focused on NOx reduction in their operations. It has helped to improve environmental conditions around their operations, and has helped to improve the health of people living in affected areas.