Selective Catalytic Reduction

Selective Catalytic Reduction (SCR) is an exhaust aftertreatment process that minimises the harmful nitrogen oxide (NOx) emissions produced by diesel engines.

The SCR reduces nitrogen oxide (NOx) molecules to molecular nitrogen and water vapour. A nitrogen-based reducing agent, such as ammonia, is used to trigger a chemical reaction in a catalytic converter that turns pollutants into harmless gasses.