Effects of Particle Filters and Selective Catalytic Reduction on Heavy-Duty Diesel Drayage Truck Emissions at the Port of Oakland

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• 作者：Chelsea V. Preble ; Timothy R. Dallmann ; Nathan M. Kreisberg ; Susanne V. Hering ; Robert A. Harley ; Thomas W. Kirchstetter
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：July 21, 2015
• 年：2015
• 卷：49
• 期：14
• 页码：8864-8871
• 全文大小：481K
• ISSN：1520-5851

文摘

Effects of fleet modernization and use of diesel particle filters (DPF) and selective catalytic reduction (SCR) on heavy-duty diesel truck emissions were studied at the Port of Oakland in California. Nitrogen oxides (NO_x), black carbon (BC), particle number (PN), and size distributions were measured in the exhaust plumes of 鈭?400 drayage trucks. Average NO_x, BC, and PN emission factors for newer engines (2010鈥?013 model years) equipped with both DPF and SCR were 69 卤 15%, 92 卤 32%, and 66 卤 35% lower, respectively, than 2004鈥?006 engines without these technologies. Intentional oxidation of NO to NO₂ for DPF regeneration increased tailpipe NO₂ emissions, especially from older (1994鈥?006) engines with retrofit DPFs. Increased deployment of advanced controls has further skewed emission factor distributions; a small number of trucks emit a disproportionately large fraction of total BC and NO_x. The fraction of DPF-equipped drayage trucks increased from 2 to 99% and the median engine age decreased from 11 to 6 years between 2009 and 2013. Over this period, fleet-average BC and NO_x emission factors decreased by 76 卤 22% and 53 卤 8%, respectively. Emission changes occurred rapidly compared to what would have been observed due to natural (i.e., unforced) turnover of the Port truck fleet. These results provide a preview of more widespread emission changes expected statewide and nationally in the coming years.