Effective emissions reduction of high-mileage fleets through a catalytic converter and oxygen sensor replacement program.

Autor: Huang Y; Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia., Lee CKC; Environmental Protection Department, Hong Kong Special Administrative Region Government, Hong Kong., Yam YS; Environmental Protection Department, Hong Kong Special Administrative Region Government, Hong Kong., Zhou JL; Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia. Electronic address: junliang.zhou@uts.edu.au., Surawski NC; Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia., Organ B; Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia; Jockey Club Heavy Vehicle Emissions Testing and Research Centre, Vocational Training Council, Hong Kong., Lei C; Centre for Wind, Waves and Water, School of Civil Engineering, The University of Sydney, NSW 2006, Australia., Shon HK; ARC Research Hub in Nutrients in a Circular Economy, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Dec 01; Vol. 850, pp. 158004. Date of Electronic Publication: 2022 Aug 12.
DOI: 10.1016/j.scitotenv.2022.158004
Abstrakt: High-mileage vehicles such as taxis make disproportionately large contributions to urban air pollution due to their accelerated engine deterioration rates and high operation intensities despite their small proportions of the total fleet. Controlling emissions from these high-mileage fleets is thus important for improving urban air quality. This study evaluates the effectiveness of a pilot repair program in reducing emissions from taxis in Hong Kong which account for about 2 % of the total licensed vehicles. The emission factors of a large sample of 684 in-service taxis (including 121 for an emission survey program and 563 for a pilot repair program) were measured on transient chassis dynamometers. The results showed that 63 % of the sampled taxis failed the driving cycle test before the pilot repair program. Most of failed taxis were NO related and 91 % of failed taxis exceeded the emission limits of at least two regulated pollutants simultaneously. After the pilot repair program by replacing catalytic converters and oxygen sensors, the failure rate was significantly reduced to only 7 %. In addition, the fleet average NO, HC and CO emission factors were reduced by 85 %, 82 % and 56 %, respectively. In addition, on-road remote sensing measurements confirmed the real-world emission reductions from the taxis that participated in the pilot repair program. These findings led to the implementation of a large-scale replacement program for all taxis in Hong Kong during 2013-2014, which was estimated to have reduced the total HC, CO and NO emissions by about 420, 2570 and 1000 t per year, respectively (equivalent to 5-8 % emission reductions from the whole road transport sector). Therefore, reducing emissions from the small high-mileage fleets is a highly cost-effective measure to improve urban air quality.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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