Abstract:
Soot formation in biodiesel combustion was studied by focusing on the major components in isolation. The aim of the
study was to establish the influence of major components on soot production in combustion of biodiesel in co-flow jet flames. The
components investigated in this study were methyl linolenate (MLe), methyl stearate (MS), methyl oleate (MO), methyl linoleate
(MLi) and methyl palmitate (MP). The study was based on Moss-Brooke’s soot model. A reduced kinetic mechanism for the
pyrolysis and combustion of biodiesel surrogates with 177 chemical species and 2904 chemical reactions was implemented.
Nucleation rate, coagulation rate, oxidation rate and soot volume fraction were investigated under laminar flow conditions. It was
established that unsaturated methyl esters had higher soot formation rates than their saturated counterparts. MLe had the greatest
influence in soot formation due to its relatively higher nucleation, coagulation and oxidation rates while MS had the least at the
same boundary conditions. Analysis of the flame structure reveals that the higher nucleation rates are correlated to higher content
of aromatic species in the immediate chemical reactions.
