The trapping system for the recirculated gases at different locations of the exhaust gas recirculation (EGR) pipe of a homogeneous charge compression ignition (HCCI) engine

Nowadays, in diesel engines, it is typical to recycle exhaust gases (EGR) in order to decrease pollutant emissions. However, few studies report the precisely measured composition of the recycled gases. Indeed, in order to know precisely the composition of the EGR gases, they have to be sampled hot and not diluted, in contrast to the usual practice. Thus, a new system to collect such samples was developed. With this new trapping system, it is possible to measure the concentrations of NOx, CO, CO2, O2, hydrocarbons (HCs) in the range C1–C9, aldehydes, ketones and PAHs. The trapping system and the analytical protocol used are described in this paper