Speciation and Chemical Evolution of Nitrogen Oxides in Aircraft Exhaust near Airports

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• 作者：Ezra C. Wood ; Scott C. Herndon ; Michael T. Timko ; Paul E. Yelvington ; Richard C. Miake-Lye
• 刊名：Environmental Science & Technology
• 出版年：2008
• 出版时间：March 15, 2008
• 年：2008
• 卷：42
• 期：6
• 页码：1884 - 1891
• 全文大小：995K
• 年卷期：v.42,no.6(March 15, 2008)
• ISSN：1520-5851

文摘

Measurements of nitrogen oxides from a variety of commercial aircraft engines as part of the JETS-APEX2 and APEX3 campaigns show that NO_x (NO_x ≡ NO + NO₂) is emitted primarily in the form of NO₂ at idle thrust and NO at high thrust. A chemical kinetics combustion model reproduces the observed NO₂ and NO_x trends with engine power and sheds light on the relevant chemical mechanisms. Experimental evidence is presented of rapid conversion of NO to NO₂ in the exhaust plume from engines at low thrust. The rapid conversion and the high NO₂/NO_x emission ratios observed are unrelated to ozone chemistry. NO₂ emissions from a CFM56-3B1 engine account for approximately 25% of the NO_x emitted below 3000 feet (916 m) and 50% of NO_x emitted below 500 feet (153 m) during a standard ICAO (International Civil Aviation Organization) landing−takeoff cycle. Nitrous acid (HONO) accounts for 0.5% to 7% of NO_y emissions from aircraft exhaust depending on thrust and engine type. Implications for photochemistry near airports resulting from aircraft emissions are discussed.