Particulate filters in a nutshell
Growing awareness of air pollution levels, as well as changing EU regulations regarding emission standards, have meant that exhaust after-treatment systems have now become a required component of engines. Diesel particulate filters (DPF) have been fitted to diesel exhaust systems for years. This obligation has had the effect of reducing emissions of the black smoke typical of diesel vehicles, thus contributing to improving the air quality.
How does a diesel particulate filter work?
When fuel is burnt in an engine, various toxic compounds are produced: carbon monoxide, nitrogen oxides, or particulate matter (PM), which among other things contribute to the formation of smog. Particulate matter, once it enters our bodies, can cause a range of illnesses and ailments: from bothersome headaches and reduced well-being to cancerous changes and disorders of the respiratory or cardiovascular systems.
Without an additional ‘barrier’, exhaust air would not meet the emission standards set by the European Union. The filter’s task is therefore to catch pollutants and stop them from entering the atmosphere.
How does this happen? DPFs have a honeycomb-like structure. It is made up of numerous porous channels made of metal and ceramic materials. It is in these that soot and ash particles are trapped and must then be burned off.