“Soot Oxidation and the Mechanisms of Oxidation-Induced Fragmentation in a Two-Stage Burner for Ethylene and Surrogate Fuels”
By Seiedhossein Ghiassi, Advisor: JoAnn Lighty

Time: 3:00 PM
Date: September 15, 2015
Location: 3291 MEB (ChE conference room)

Soot is the unwelcome by-product in many combustion systems such as industrial flames, auto engines, etc. that may have adverse effects on human health and the environment. In real combustion devices, a determinant role for the particle emissions is played by the oxidation processes. Therefore, a better understanding of soot oxidation mechanisms would allow us to mitigate the soot emissions.

The present study has two main objectives and the first one evaluates the effect of n-butanol on the sooting behavior of n- dodecane (a diesel surrogate) in a two-stage burner. n-Butanol has attracted much attention in the combustion community, due to its high energy density and good solubility in both gasoline and diesel. This part addresses the impact of increasing n- butanol on the oxidative reactivity of soot by evaluating soot nanostructures as well as oxygen surface functional groups. In addition, the soot reduction effect of methyl decanoate, a biodiesel surrogate in n-dodecane is investigated and the results are compared to that of n-butanol/n-dodecane mixtures.

The second objective is identifying the condition where soot oxidation-induced fragmentation occurs by using ethylene fuel in the two-stage burner. The mechanisms of soot oxidation-induced fragmentation are explored by following changes in mobility size, number and concentration, flame temperature, and gas-phase compositions. In addition, the current hypotheses for fragmentation suggested in the literature are evaluated by the aid of image analysis technique.