AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Morphology and Optical Properties of Soot
Georgios Kelesidis, SOTIRIS E. PRATSINIS, ETH Zurich
Abstract Number: 9 Working Group: Aerosols, Clouds and Climate
Abstract There is renewed interest in understanding the detailed structure and optical properties of soot as it is the second largest contributor (after CO2) to radiative forcing. In addition, soot exhibits by far the largest uncertainty (90%) of all such contributors. Furthermore, this understanding is still sought for reliable monitoring of soot emissions, carbon black processing and fire detection. Here, soot surface growth, agglomeration [1] and oxidation are elucidated by discrete element modeling (DEM) and compared to experimental data at various combustion conditions from different laboratories. The classic Rayleigh-Debye-Gans (RDG) theory is revised by coupling the discrete dipole approximation (DDA) to these DEM-derived agglomerates [2]. So by accounting for the morphology and composition of soot, the evolution of its light absorption and scattering in premixed flames is elucidated. That way both DEM-DDA and revised RDG theory can be readily used for optimizing the selectivity of fire detectors and advancing soot optical diagnostics, as well as for a more accurate estimation of the climate impact of soot.
[1] Kelesidis, G.A., Goudeli, E., Pratsinis, S.E., “Morphology and mobility diameter of carbonaceous aerosols during agglomeration and surface growth”, Carbon 121 527-535 (2017). [2] Kelesidis, G.A., Kholghy, M.R., Zuercher, J., Robertz, J., Allemann, M., Duric, A., Pratsinis, S.E., Light scattering from nanoparticle agglomerates, Powder Technol. (2019) doi.org/10.1016/j.powtec.2019.02.003.