Beijing LICA United Technology Limited

Novel Instruments Provide New Opportunities

Hotline: 010-51292601
Technical Technical
News Technical

ABB LGR | Emissions of Ammonia and Other Nitrogen-Containing Volatile Organic Compounds from Motor V

Date: 2022-06-01
浏览次数: 6

Emissions of Ammonia and Other Nitrogen-Containing Volatile Organic Compounds 

from Motor Vehicles under Low-Speed Driving Conditions

ABB LGR | Emissions of Ammonia and Other Nitrogen-Containing Volatile Organic Compounds from Motor V

Ammonia (NH3) and amines are major alkaline gases in the atmosphere. Despite their relatively low ambient concentrations (a few ppbv for NH3 and several pptv for amines), these trace gases can significantly impact atmospheric chemical processes. Globally, agriculture-related activities and anthropogenic sources are recognized as the important NH3 source. And recent field studies found that motor vehicles are also a potential source of amines that could be responsible for the enhanced nucleation events in Beijing, China. As organic derivatives of NH3, amines often share with NH3 their source profiles, but the magnitude of amine emissions is still unknown. In light of the drastically increased personal car ownership in China, motor vehicles are expected to play a progressively more important role in primary air pollutant emissions, particularly in urban environments. Therefore, an in-depth investigation of vehicular emissions of NH3 and amines is of practical importance for formulating air pollution abatement strategies.

Based on this, in this study, a group of Chinese scientists deployed a water-cluster chemical ionization mass spectrometer along with other trace gas monitors on the roadside of the campus of Nanjing University Information Science and Technology (NUIST; N32°1227, E118°4231) to characterize individual in-use motor vehicle’s emission ratios (ER) for NH3 and nine amine-derived nitrogen-containing volatile organic compounds (NVOCs) that contain 1 to 3 carbon atoms (i.e., C1−3-amines, C1−3-imines, and C1−3- amides). These results are analyzed to identify the individual emission profiles of gasoline-powered passenger cars (GP), diesel-powered light-duty trucks (DT), and natural-gas powered taxis (NT).

Among the other trace gas monitors, the concentration of carbon dioxide (CO2) was measured with a commercial instrument (Los Gatos Research, LGR), which can simultaneously detect dry mixing ratios of CO2, methane (CH4), and water vapor based on a fourth-generation cavity enhanced absorption technique. CO2 within the vehicle exhausts was measured at a time resolution of 10 Hz with a noise level of 1.4 ppmv. Given the typical high concentrations of CO2 within the exhaust (1000 ppmv), the uncertainty associated with CO2 measurements is around 0.1%.

[Results]:

 The total emission strength of diesel trucks was the greatest followed by those of gasoline cars and natural gas cars. NH3 emission per vehicle was found to be 2−3 orders of magnitude greater than that of all NVOCs, regardless of the type of vehicle. Although much lower than the emissions of amides or imines, emissions of amines were sufficient to produce atmospheric concentrations exceeding the threshold level for amines to enhance atmospheric nucleation by several orders of magnitude. Different engine emission reduction technologies (e.g., three-way catalytic converter vs selective catalytic reduction) can lead to different NH3 and NVOC emission profiles. During the lifetime of a vehicle, its emission level was most likely to increase with its mileage. Source profiles of NH3 and NVOC emissions from the three types of vehicles were also obtained from the measurements.

Table 1. Summary of Emission Ratios (avg ± σ) of NH3 and NVOCs for: Gasoline-Powered Passenger Cars (GP), Diesel-Powered Light-Duty Trucks (DT), and Natural Gas-Powered Taxis (NT).

ABB LGR | Emissions of Ammonia and Other Nitrogen-Containing Volatile Organic Compounds from Motor V


ABB LGR | Emissions of Ammonia and Other Nitrogen-Containing Volatile Organic Compounds from Motor V

Figure 2. Emission profiles of GP, DT, and NT vehicles obtained from the mass spectra generated by the water cluster-CIMS. The statistics shown in the legend are based on a sample space of 63 GP, 14 DT, and 12 NT vehicles, respectively.


ABB LGR | Emissions of Ammonia and Other Nitrogen-Containing Volatile Organic Compounds from Motor V

Figure 3. Emission ratios of NH3 and NVOCs of gasoline-powered passenger cars segmented by vehicle mileage (panel a), years in service (panel b), and emission standards implemented (panel c), that is, Chinese national standard IV (China IV) and V (China V), respectively.

[Conclusion]:

The authors concluded that these profiles can be a valuable contribution to the air pollution management system in terms of source apportionment, elucidating the emission contributions from a specific type of vehicle.


News / Related News More
2022 - 12 - 30
Cherry tomato (Solanum lycopersicum) is popular with consumers over the world due to its special flavor. Soluble solids content (SSC) and firmness are two key metrics for evaluating the product qualities. The existing measuring techniques relying upon chemistry reactions can derive the SSC value accurately. However, the destructive methods can not be applied in high volume measurements. Moreover, ...
2022 - 12 - 28
In the Arctic, the air temperature has increased more than twice the global average during the last few decades and may increase by 2-8°C before 2100. Wildfire frequency and expanse in the Arctic have increased in recent years. It can markedly disturb tundra ecosystems in different ways, including above-and belowground plant biomass destruction and alter soil properties through changes in the...
2022 - 12 - 06
Heavy metals in soil are harmful, and their migration and accumulation can seriously threaten ecological environmental security and human health. Arsenic (As) exhibits high neurotoxicity and teratogenicity. Much As is released into soil during human activities, including mining operations and industrial production activities. Determining the As concentration in soil quickly and accurately is impor...
2022 - 11 - 30
The pine wood nematode (Bursaphelenchus xylophilus) is a dangerous invasive species that causes pine wilt disease (PWD), which has already destroyed enormous areas of pine forest in China. Therefore, early-stage PWD detection is crucial for a prompt management response. Hyperspectral RS uses data from hundreds of bands and continuous wavelengths, and these bands can capture physiological changes i...
Close window】【Print
Copyright ©2018-2023 LICA United Technology Limited
犀牛云提供企业云服务

LICA United Technology Limited

Address:The 5th.Building,No.18,Anningzhuang East Road,Haidian District, 100085, Beijing, China.

Tel:010-51292601
Fax:010-82899770-8014
E-mail:info@li-ca.com

 


 

 


 
  • Name:
  • *
  • 公司名称:
  • *
  • 地址:
  • *
  • 电话:
  • *
  • 传真:
  • *
  • E-mail:
  • *
  • 邮政编码:
  • *
  • 留言主题:
  • *
  • Details:
  • *
Feedback
Follow us
  • Wechat
  • Mobile Website
友情链接: