Pre-Turbocharger-Catalyst - Catalytic Performances on an Euro V Type Diesel Engine and Robust Design Development

Future emission legislation and new diesel engine technology tighten the requirements for modern diesel vehicle exhaust after-treatment systems. In particular, the oxidation catalyst system requires more efficiency to treat increasing raw emissions of HC and CO at low exhaust gas temperatures resulting from advanced combustion processes. This represents a big challenge for all developers today where the cost of raw materials continues to rise.

Splitting the oxidation catalyst volume into two parts and mounting a very small part in front of a turbocharger on Euro III or Euro IV Diesel engines has been proved very efficient: Light off and maximum pollutant conversion rates were improved. New results gained with Pre Turbocharger Catalyst (PTC) on a Euro V type diesel engine are confirming previous observations.

The complete after-treatment system of today's vehicles should be designed and developed for the whole life of the vehicle. Due to its position in front of the turbine any failure of the PTC, in either the metal substrate or of the coating, would result in particularly severe consequences due to turbine damage and/or loss of turbine function. A robust design for the metal substrate has been defined with the help of Finite Element simulation of thermal stress and has then been validated on the component test bench.