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Accueil du site > Thèmes de recherche > Combustion & systèmes réactifs > 1.2 Formation and reduction of pollutants from combustion > 1.2.2 Soot and precursors

1.2.2 Soot and precursors Formation of PAH and soot precursors
Soot is still one of the most difficult combustion generated pollutant to reduce. The formation of soot precursors (benzene, cyclopentadiene, PAH) was studied in a JSR and a chemical kinetic modelling was performed within a research program of ESA-MAP "ombustion Properties of Materials for Space Applications Phase 2 (2005-2012) in collaboration with LCD in Poitiers, the Universities of Lund and Cottbus. Analytical procedures involving HPLC-UV-Fluo-MS, and GC-MS were developed to measure PAH at low concentration levels. This work was extended to the measurement of PAH on soot obtained from the combustion of kerosene and mixtures containing bio-fuels (ACL102). Soot Formation
Despite a tremendous work-effort by the research community during the last decades, soot formation and oxidation remains one of the most challenging phenomena in the combustion field. Due to the harmful effects of soot particles both on health and environment, governments worldwide have strengthened the emission regulations for automotive engines. The reduction of Diesel soot emissions were and still are a target of these regulations since this combustion mode is prone to soot production. During the last decade, we have developed a powerful tool in order to study soot formation and oxidation based on a shock tube coupled to laser techniques such as extinction and Rayleigh diffusion. Based on soot sampling techniques, the organization (TEM low resolution), structure (TEM high resolution) as well as the adsorbed phase (LDI-TOF-MS) were thoroughly investigated. The ICARE heated shock tube allows conducting fundamental studies on heavy pure fuels or commercial fuels at conditions relevant to internal combustion engines (high pressures and temperatures). These studies were conducted in the framework of several co-operations with TOTAL, CNR-Milano within the Franco-Italian GDRE on Hydrogen Combustion and Safety, and the University of Toronto. This last cooperation aims the modelling of soot formation by coupling a detailed kinetic mechanism for soot precursors to a global soot formation code (ACL41, ACL178-180). Modelling of soot formation in Diesel engine conditions
A modelling study of soot formation in a Diesel engine has been performed in collaboration with Renault and PRISME-University of Orléans in order to optimize IC engines for soot emissions reductions. A soot model was developed and coupled to a combustion model (for benzene, n-heptane, iso-octane, n-decane and toluene oxidation) in a 3D-CFD code (ACL62, ACTI7).