Sato, S., Nakamura, Y., Hirabayashi, H., Sato, S. et al., "Characterization of Emissions from Urea-SCR and DPF System for Heavy Duty Engine," SAE Technical Paper 2015-01-2016, 2015, doi:10.4271/2015-01-2016.
Urea selective catalyst reduction (SCR) systems have a high NOx conversion rate because the ammonia formed by the hydrolyzing urea solution reacts with NOx efficiently as a reducing agent. Systems combining urea-SCR and a diesel particulate filter (DPF) have been adopted in heavy duty vehicles to meet the post new long term emissions regulations in Japan.This study examined the emissions reduction performance of these systems after 160,000 km. The emissions that were examined included both regulated emissions (NOx, PM, HC, and CO) and unregulated emissions. As a result, the cleanness of diesel emissions from a urea-SCR and DPF system was confirmed.