Unreported VOC Emissions from Road Transport Including from Electric Vehicles

TY - JOUR

T1 - Unreported VOC Emissions from Road Transport Including from Electric Vehicles

AU - Cliff, Samuel J

AU - Lewis, Alastair C

AU - Shaw, Marvin D

AU - Lee, James D

AU - Flynn, Michael

AU - Andrews, Stephen J

AU - Hopkins, James R

AU - Purvis, Ruth M

AU - Yeoman, Amber M

N1 - Funding Information: Measurements were funded by the U.K. Natural Environment Research Council through the OSCA (Integrated Research Observation System for Clean Air) project of the Clean Air Strategic Priority Fund (Grant numbers NE/T001917/1 and NE/T001798/2). S.C. was supported by the Panorama Natural Environment Research Council (NERC) Doctoral Training Partnership (DTP), under grant NE/S007458/1. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.

PY - 2023/5/16

Y1 - 2023/5/16

N2 - There are widespread policy assumptions that the phase-out of gasoline and diesel internal combustion engines will over time lead to much reduced emissions of Volatile Organic Compounds (VOCs) from road transport and related fuels. However, the use of real-world emissions measurements from a new mobile air quality monitoring station demonstrated a large underestimation of alcohol-based species in road transport emissions inventories. Scaling of industry sales statistics enabled the discrepancy to be attributed to the use of ancillary solvent products such as screenwash and deicer which are not included in internationally applied vehicle emission methodologies. A fleet average nonfuel nonexhaust VOC emission factor of 58 ± 39 mg veh -1 km -1 was calculated for the missing source, which is greater than the total of all VOCs emitted from vehicle exhausts and their associated evaporative fuel losses. These emissions are independent of the vehicle energy/propulsion system and therefore applicable to all road vehicle types including those with battery-electric powertrains. In contrast to predictions, vehicle VOC emissions may actually increase given a predicted growth in total vehicle kilometers driven in a future electrified fleet and will undergo a complete VOC respeciation due to the source change.

AB - There are widespread policy assumptions that the phase-out of gasoline and diesel internal combustion engines will over time lead to much reduced emissions of Volatile Organic Compounds (VOCs) from road transport and related fuels. However, the use of real-world emissions measurements from a new mobile air quality monitoring station demonstrated a large underestimation of alcohol-based species in road transport emissions inventories. Scaling of industry sales statistics enabled the discrepancy to be attributed to the use of ancillary solvent products such as screenwash and deicer which are not included in internationally applied vehicle emission methodologies. A fleet average nonfuel nonexhaust VOC emission factor of 58 ± 39 mg veh -1 km -1 was calculated for the missing source, which is greater than the total of all VOCs emitted from vehicle exhausts and their associated evaporative fuel losses. These emissions are independent of the vehicle energy/propulsion system and therefore applicable to all road vehicle types including those with battery-electric powertrains. In contrast to predictions, vehicle VOC emissions may actually increase given a predicted growth in total vehicle kilometers driven in a future electrified fleet and will undergo a complete VOC respeciation due to the source change.

KW - air pollution

KW - ethanol

KW - screenwash

KW - urban atmosphere

KW - volatile chemical products

UR - http://www.scopus.com/inward/record.url?scp=85160702933&partnerID=8YFLogxK

U2 - 10.1021/acs.est.3c00845

DO - 10.1021/acs.est.3c00845

M3 - Article

C2 - 37191998

SN - 0013-936X

JO - Environmental science & technology

JF - Environmental science & technology

ER -