Long-Term Fuel-Specific NOx and Particle Emission Trends for In-Use Heavy-Duty Vehicles in California

Authors

Molly J. Haugen, University of DenverFollow
Gary A. Bishop, University of DenverFollow

Publication Date

2018

Document Type

Article

Organizational Units

Chemistry and Biochemistry

Keywords

Atmospheric chemistry, Emissions, Pollutants, Heavy-duty diesel trucks

Abstract

Two California heavy-duty fleets have been measured in 2013, 2015 and 2017 using the On-road Heavy-duty Measurement System. The Port of Los Angeles drayage fleet has increased in age by 3.3 model years (4.2 to 7.5 years old) since 2013, with little fleet turnover. Large increases in fuel specific particle emissions (PM) observed in 2015 were reversed in 2017, returning to near 2013 levels, suggesting repairs and or removal of high emitting vehicles. Fuel specific oxides of nitrogen (NO_x) emissions of this fleet have increased and NO_x after-treatment systems do not appear to perform ideally in this setting. At Cottonwood weigh station in northern California, the fleet age has declined (7.8 to 6 years old) since 2013 due to fleet turnover significantly lowering the average fuel specific emissions for PM (-87%), black carbon (-76%) and particle number (-64%). Installations of retrofit-diesel particulate filters in 2007 and older vehicles have further decreased particle emissions. Cottonwood fleet fuel specific NO_x emissions have decreased slightly (-8%) during this period, however, newer technology vehicles with selective catalytic reduction systems (SCR) promise an additional factor of 4 to 5 further reductions in the long-haul fleet emissions as California transitions to an all SCR equipped fleet.

Copyright Statement / License for Reuse

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

Rights Holder

Molly J. Haugen, Gary A. Bishop

Provenance

Received from author

File Format

application/pdf

Language

English (eng)

Extent

32 pgs

File Size

590 KB

Publication Statement

This is an Accepted Manuscript for

Haugen, M. J.; Bishop, G. A. (2018) Long-Term Fuel-Specific NOx and Particle Emission Trends for In-Use Heavy-Duty Vehicles in California. Environ. Sci. Technol., 52(10), 6070-6076. DOI: 10.1021/acs.est.8b00621.

Copyright held by the American Chemical Society. User is responsible for all copyright compliance.

Recommended Citation

Haugen, M. J.; Bishop, G. A. (2018) Long-Term Fuel-Specific NOx and Particle Emission Trends for In-Use Heavy-Duty Vehicles in California. Environ. Sci. Technol., 52(10), 6070-6076. DOI: 10.1021/acs.est.8b00621.

DOI Link

https://doi.org/10.1021/acs.est.8b00621