Exhaust aftertreatment device-derived ammonia emissions from conventional and hybrid light-duty gasoline vehicles over different driving cycles

Han Jiang; Hefeng Zhang; Haiguang Zhao; Mingliang Fu; Yunjing Wang; Xian Wu; Xinping Yang; Jianglin Ji; Hang Yin; Yan Ding

doi:10.1016/j.jhazmat.2023.131914

Exhaust aftertreatment device-derived ammonia emissions from conventional and hybrid light-duty gasoline vehicles over different driving cycles

J Hazard Mater. 2023 Sep 15:458:131914. doi: 10.1016/j.jhazmat.2023.131914. Epub 2023 Jun 22.

Authors

Han Jiang¹, Hefeng Zhang¹, Haiguang Zhao¹, Mingliang Fu², Yunjing Wang¹, Xian Wu¹, Xinping Yang¹, Jianglin Ji¹, Hang Yin³, Yan Ding⁴

Affiliations

¹ State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Vehicle Emission Control Center of Ministry of Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
² State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Vehicle Emission Control Center of Ministry of Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: fumingliang160@163.com.
³ State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Vehicle Emission Control Center of Ministry of Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: yinhang@vecc.org.cn.
⁴ State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Vehicle Emission Control Center of Ministry of Ecology and Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: dingyan@vecc.org.cn.

PMID: 37379594
DOI: 10.1016/j.jhazmat.2023.131914

Abstract

Ammonia emissions from motor vehicles have great effect on air pollution and human health in urban areas. Recently, many countries have focus on ammonia emission measurement and control technologies for light-duty gasoline vehicles (LDGVs). To analyze ammonia emission characteristics, three conventional LDGVs and one hybrid electric light-duty vehicle (HEV) were evaluated over different driving cycles. The average ammonia emission factor at 23℃ was 4.5 ± 1.6 mg/km over Worldwide harmonized light vehicles test cycle (WLTC). Most ammonia emissions mainly concentrated in low and medium speed sections at cold-start stage, which were related to rich burn conditions. The increasing ambient temperatures led to the decrease of ammonia emissions, but high load caused by extremely elevated ambient temperature led to obvious ammonia emissions. The ammonia formation is also related to three-way catalytic converter (TWC) temperatures, and underfloor TWC catalyst could eliminate ammonia partly. The ammonia emission from HEV, which are significant less than LDGV, corresponded to the engine working state. The large temperature difference in the catalysts caused by power source shifts were the main reason. Exploring the effects of various factors on the ammonia emission is beneficial for revealing the instinct formation conditions, providing theoretical support for the future regulations.

Keywords: Ammonia emission; Hybrid electric light-duty vehicle; Light-duty gasoline vehicle; Rich burn; TWC catalyst.