Vehicle approval certifies that the emissions of said vehicle meet the specifications imposed by existing standards. Although current regulations only concern a limited number of chemical species, the impact of the latter on human health and the environment is
leading to a tightening up of legislation, with a reduction in emission thresholds and the inclusion of new pollutants.

Consequently, there is a need for a more in-depth understanding of the various types of chemical species emitted and their concentrations, depending on vehicle operating modes. To address this need, IFPEN coordinated two projects that shed light on emissions – regulated or not – from vehicles representative of the French market.

The Cappnor project highlighted:

high levels of ultra-fine particle emissions from a gasoline direct injection powertrain (figure),
• the very high efficiency of Diesel particle filters, thanks to which the exhaust emission concentrations are indistinguishable from urban atmospheric levels(1).

The Cappnor 2 project demonstrated that the efficiency of the two major technologies aimed at reducing nitrogen oxide emissions (NOx)aof Diesel engines was heavily dependent on the way they were implemented by manufacturers within the various engine operating ranges(2).

Particle concentrations (color) emitted by a gasoline
direct injection vehicle: evolution over time
depending on their diameter when speed varies
(gray curve) (b).

Vehicle approval procedures evolved in 2017 to ensure low emission levels over a broader range of use of an internal combustion engine. The results of these two projects provide legislators with a basis for defining improved emission reduction measures. They also indicate the development priorities that IFPEN should be focusing on in terms of designing new pollution control systems.

In parallel, the continuous improvement process is being pursued with the Rhapsodie project, focusing on the various forms of polycyclic aromatic hydrocarbons present in particles and in the gas phase.

a - Catalytic reduction using urea (SCR Selective Catalytic Reduction) and NOx trap (LNT: Lean NOx Trap).
b - When the speed (gray curve) and the temperature entering the catalytic converter (red curve) are varied.


(1) S. Zinola, S. Raux, M. Leblanc, SAE Technical Paper 2016-01-2283, 2016.
    >> DOI : 10.4271/2016-01-2283

(2) M. Leblanc, L. Noël, B. R’Mili, A. Boréave, B. D’Anna, S. Raux, Journal of Earth Sciences and Geotechnical Engineering, vol.6, no. 4, 2016, 29-50
   >> https://www.scienpress.com/journal_focus.asp?main_id=59&Sub_id=IV&Issue=1921


Scientific contact: Stéphane Raux