More NO₂ – Better regeneration
Improved NO₂ performance *
The diesel particulate filter traps the solid combustion residues from the combustion engine. In addition to diesel exhaust particles, microscopically small carbon particles with a size less than 1,000 millimetres up to 10 µm, other different hydrocarbon compounds as well as metal oxides and sulphur adhere to this filter.
Normally the carbon in the sooty particle is burned continuously while driving. For this purpose, a catalytic converter is located upstream of the diesel particulate filter or the catalytic coating is applied to the diesel particulate filter itself. Part of the NO present in the exhaust gas is oxidised into NO₂ through this coating. This NO₂ reacts with the sooty particles caught in the filter, burns these and in the process again generates NO and CO₂. This NO is then again oxidised into NO₂ in the filter and again reacts with the sooty particles. This process continues whenever the exhaust gas temperature in the filter is above 250° C.
However, unfavourable operating conditions, increased carbon-particulate emissions of the engine as well as technical faults often prevent a complete regeneration of the embedded sooty particles, since these sooty particles are deposited on the catalytic coating.
Thanks to the cleaning, the catalytic function of the coating is reactivated and the carbon-particulate matter is regenerated faster and more effectively while driving due to the improved NO₂ performance. This means less exhaust gas back pressure, lower fuel consumption as well as optimal engine performance. In addition, the risk of possible damage to the engine and filter is minimised.