An Investigation on Aldehyde and Ammonia Emissions from a 4-Stroke Gasoline-Fueled Motorcycle - Ammonia Emission Reduction by using a SCR Catalyst

摘要

In order to comply with the introduction of new emission limits, motorcycles have been equipped with electronic injection systems and three-way catalytic converters for emissions abatement. However, these converters produce unwanted reactions, such as the formation of ammonia. This paper was focused on ammonia emission reduction in motorcycles. To provide ammonia abatement, one SCR (Selective Catalytic Reduction) catalyst has been developed and installed in a four-stroke motorcycle in addition to the original one, a three way catalyst (TWC). SCR systems work by chemically reducing NO_x (NO and NO_2) to nitrogen (N_2). This is an experimental research work conducted by the Research and Development Institute (Lactec) and the Umicore Automotive Catalysts. Regulated and unregulated emissions have been measured in a chassis dynamometer test cell. The results show that it is possible to reduce ammonia emissions, but the SCR catalyst performance has to be improved by optimizing the SCR technology and position, increasing the temperature inside the SCR, and promoting proper chemical reaction to reduce NO_x.