Abstract
In this study, formation process of deposit adhering on an EGR simulated sample line was investigated using attenuated total reflection-Fourier transform infrared spectrometry (ATR-FTIR). Exhaust gas of a diesel engine passing through diesel particulate filter (DPF) was introduced into the sample line. Time-resolved infrared absorption spectra of the deposit were obtained for 6 hours from the beginning of the experiment including water condensation and evaporation process. Absorption peaks of C=O, C-H, and C=C were observed after condensed water has disappeared, and those absorption peaks increase with increasing the deposition time. The change of the ATR-FTIR spectra was not observed in formation process of the deposit. These findings suggest that EGR deposit were simply formed by condensation or adsorption of hydrocarbons having functional groups such as C=O, C-H, and C=C in exhaust gas.
