Brendan Carberry

Pre-Turbocharger Catalyst - Fast catalyst light-off evaluation

Further tightened emission legislation and new engine technologies increase the requirements for the exhaust after-treatment system of modern diesel passenger cars. Especially the increasing raw emissions of HC and CO as well as the low temperature of the exhaust gas for a long period during cold start of the New European Driving Cycle (NEDC) require additional efforts in the design of the oxidation catalyst system [1]. A highly efficient micro catalyst, which is mounted in front of a turbocharger, can help to treat efficiently these high HC and CO emissions. Due to the higher temperature level in front of the turbine and the significantly increased mass and heat transfer by turbulent flow, efficiency especially during cold start is highly increased. However the packaging constraints are more critical in this area due to heat considerations and also to maintain engine performance. The PreTurbocharger Catalyst (PTC) is able to balance the total functionality and has a high potential to make the Diesel Oxidation Catalyst (DOC)more efficient.

Development of PGM-free catalysts for automotive applications

The activity of Ag-based catalysts in soot oxidation using NO2 and oxygen as oxidants has been characterized in laboratory tests (TGA) and under real conditions on an engine dynamometer. Under low-temperature NO2-assisted and high-temperature O2-assisted soot oxidation conditions, the activity of Ag-based catalysts was found to be comparable or higher than that of commercial Pt-catalysts. In addition, Ag-based compositions also revealed noticeable NOx storage, some passive NOx reduction ability, and activity in NO oxidation. Ag-catalysts characterized in the present paper may be promising for the retrofit applications and high-temperature periodical regenerations with air for diesel passenger cars.

Diesel Particulate Filter Regeneration: Control of Calibration?

Abstract Diesel particulate filters are an efficient means of reducing particulate emissions of diesel engines by orders of magnitude. The necessary periodical regeneration of these filter systems requires drastic changes in the engine management, notably in fuel and air path control, because the temperature levels required for regeneration are 200°-400°C above normal levels. The approach taken to address this problem is described in this paper. It is at the same time used to illustrate typical engine control challenges and explains why model-based control methods still find only limited application in powertrain control. In particular, the importance of feedforward control is stressed, leading to the question: Control or Calibration?