Characterizing emission rates of regulated pollutants from model year 2012+ heavy-duty diesel vehicles equipped with DPF and SCR systems

Yu Jiang; Jiacheng Yang; David Cocker 3rd; Georgios Karavalakis; Kent C Johnson; Thomas D Durbin

doi:10.1016/j.scitotenv.2017.11.120

Characterizing emission rates of regulated pollutants from model year 2012+ heavy-duty diesel vehicles equipped with DPF and SCR systems

Sci Total Environ. 2018 Apr 1:619-620:765-771. doi: 10.1016/j.scitotenv.2017.11.120. Epub 2017 Nov 29.

Authors

Yu Jiang¹, Jiacheng Yang¹, David Cocker 3rd¹, Georgios Karavalakis¹, Kent C Johnson¹, Thomas D Durbin²

Affiliations

¹ Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92507, United States; Bourns College of Engineering - Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, CA 92507, United States.
² Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92507, United States; Bourns College of Engineering - Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, CA 92507, United States. Electronic address: durbin@cert.ucr.edu.

PMID: 29161601
DOI: 10.1016/j.scitotenv.2017.11.120

Abstract

The regulated emissions of five 2012 and newer, low-mileage, heavy-duty Class 8 diesel trucks equipped with diesel particulate filters (DPFs) and selective catalytic reduction (SCR) systems were evaluated over test cycles representing urban, highway, and stop-and-go driving on a chassis dynamometer. NOx emissions over the Urban Dynamometer Driving Schedule (UDDS) ranged from 0.495 to 1.363g/mi (0.136 to 0.387g/bhp-hr) for four of the normal emitting trucks. For those trucks, NOx emissions were lowest over the cruise (0.068 to 0.471g/mi) and high-speed cruise (0.067 to 0.249g/mi) cycles, and highest for the creep cycle (2.131 to 9.468g/mi). A fifth truck showed an anomaly in that it had never regenerated throughout its relatively short operating lifetime due to its unusual, unladed service history. This truck exhibited NOx emissions of 3.519g/mi initially over the UDDS, with UDDS NOx emissions decreasing to 0.39g/mi after a series of parked regenerations. PM, THC, and CO emissions were found to be very low for most of the testing conditions, due to the presence of the DPF/SCR aftertreatment system, and were comparable to background levels in some cases.

Keywords: Emission inventories; Heavy-duty diesel vehicles; NO(X) emissions; Selective catalytic reduction.