Urea is an important raw material for the chemical industry. It is widely used in NOx control systems to reduce nitrogen oxides emissions.
The process commonly used is called selective catalytic reduction (SCR). A post-combustion NOX reduction technology in which ammonia (NH3) is added to the fuel gas passing through layers of a catalyst. The ammonia and NOX react on the surface of the catalyst and form harmless nitrogen (N2) and water vapor.