On-road emissions from urban buses with SCR plus Urea and EGR plus DPF systems using diesel and biodiesel

Due to growing concerns about NO(x) and particulate matter (PM) emissions from diesel engines, stricter regulations are being introduced requiring advanced emission control technology. In response the diesel industry has begun testing various emission control technologies and applying them. To assess vehicle renewal policies of bus companies, two exhaust after-treatment technologies are compared: the combination of a diesel particulate filter and an exhaust gas re-circulation system and the combination of a selective catalytic reduction and urea. On-board emission measurements were conducted under real-world driving conditions on a specific bus route in the city of Madrid. (C) 2008 Elsevier Ltd. All rights reserved.