title: Investigation of NH3 emissions from new technology vehicles as a function of vehicle operating conditions.
abstract: The objective of this study was to measure ammonia (NH3) emissions from modern technology vehicles since information is scarce aboutthis importantsource of particulate matter (PM) precursors. Test variables included the emission level to which the vehicle was certified, the vehicle operating conditions, and catalyst age. Eight vehicles with low-emission vehicle (LEV) to super-ultralow-emission vehicle (SULEV) certification levels were tested over the Federal Test Procedure (FTP75), a US06 cycle, a hot running 505, a New York City Cycle (NYCC), and a specially designed Modal Emissions Cycle (MEC01v7) using both as-received and bench-aged catalysts. NH3 emissions in the raw exhaust were measured by tunable diode laser (TDL) absorption spectroscopy. The results show that NH3 emissions depend on driving mode and are primarily generated during acceleration events. More specifically, high NH3 emissions were found for high vehicle specific power (VSP) events and rich operating conditions. For some vehicles, NH3 emissions formed immediately after catalyst light-off during a cold start.
authors: Bourns College of Engineering, Center for Environmental Research and Technology, University of California, Riverside, California 92521, USA.
authors: Tao
authors: T
authors: Huai
authors: Thomas D
authors: TD
authors: Durbin
authors: J Wayne
authors: JW
authors: Miller
authors: John T
authors: JT
authors: Pisano
authors: Claudia G
authors: CG
authors: Sauer
authors: Sam H
authors: SH
authors: Rhee
authors: Joseph M
authors: JM
authors: Norbeck
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000032:analysis*; D004867:Equipment Design; D007834:Lasers; D018986:Motor Vehicles; D010316:Particle Size; D013696:Temperature; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D001335:Vehicle Emissions; D000641:Ammonia