selective catalytic reduction chemical reaction
When nitrogen oxides (NO x ) are emitted into the exhaust gas flow before treatment, selective catalytic reduction (SCR) is an accredited chemical process for preventing their release into the environment. In this process, a liquid reductant agent which is usually urea, is injected into the combustion products. Urea splits into ammonia, which reacts with the NO x catalyzed by a NOx at to yield harmless nitrogen and water. The main functions of SCR technology are to meet stringent environmental regulations, improve air quality and reduce the carbon footprint of industry or means of transport. Technological features of SCR include the use of advanced catalysts that are robust and effective even at high temperatures, as well as precise dosing systems to ensure the right amount of reductant is used. SCR systems are in wide use on products such as power generation, cement production, heavy-duty diesel vehicles and more.