Novel emission technologies with emphasis on catalyst cold start improvements Status report on VW-Pierburg burner/catalyst systems

摘要

Intensive research and development activities which have been carried out by automotive manufacturers and suppliers of the automotive industry are currently focused on new solutions to meet the strict exhaust gas emission standards defined by LEV, ULEV and EG III. While both CO and HC emissions have been curtailed further and require novel emission technologies, the latter takes on a higher priority due to drastic reduction imposed by ULEV regulations. In current emission control systems with three-way catalysts, the major part of these emissions is created during cold start and warm-up phases when the catalyst temperature is below its light-off temperature. The present paper reports on burner/catalyst systems for improving the catalyst's cold start performance, which is a novel technology compared to other known technologies such as electrically heated catalysts (EHC) and adsorbers. The burner system heats up the catalyst rapidly to its light-off temperature and reduces the cold start emissions without a noticeable fuel penalty. The present paper describes the current state of development of this burner/catalyst system. It provides conversion data obtained from vehicles of Volkswagen Group and suggests additional improvements to reduce cold start emissions further.