NH3 and N2O real world emissions measurement from a CNG heavy duty vehicle using on-board measurement systems

The development and utilization of a series of after-treatment devices in modern vehicles has led to an increase on emissions of NH3 and/or N2O with respect to the past. N2O is a long-lived greenhouse gas and an ozone-depleting substance, while NH3 ¬is a precursor of secondary aerosols in the atmosphere. Certain regions, e.g., EU or USA, have introduced limits for the emissions of NH3 or N2O, for vehicles tested in the laboratory. However, due to the lack of on-board systems that allowed the measurement of these compounds when the regulations were developed, their real world emissions have not been regulated. This work evaluates on-board systems that could allow the measurement of real world emissions of NH3 and N2O from heavy-duty vehicles. In particular, emissions of NH3 or N2O from a Euro VI Step D urban/interurban bus fuelled with Compressed Natural Gas were measured using the HORIBA’s OBS-ONE-XL, which is based on a specifically developed technique called Infrared Laser Absorption Modulation and uses a Quantum Cascade Laser as a light source, and the PEMS-LAB, that is a more conventional FTIR-based system. Emissions were measure under real world driving conditions on the road and in a climatic test cell at different ambient temperatures. For most of the conditions tested, the on-board systems nicely correlate with a laboratory grade FTIR used as reference. In addition, a good correlation with R2 > 0.9, was found for the N2O concentrations measured by OBS-ONE-XL and PEMS-LAB during on-road testing.

SUAREZ BERTOA Ricardo;  GIORIA Roberto;  SELLERI Tommaso;  LILOVA Velizara;  MELAS Anastasios;  ONISHI Yusuke;  FRANZETTI Jacopo;  FORLONI Fabrizio;  PERUJO MATEOS DEL PARQUE Adolfo; 

2021-11-24

MDPI

JRC126409

2076-3417 (online),   

https://www.mdpi.com/2076-3417/11/21/10055,    https://publications.jrc.ec.europa.eu/repository/handle/JRC126409,   

10.3390/app112110055 (online),