posted on 2020-02-05, 12:03authored bySarah Arvelos, Carla Eponina Hori
The
goal of this study was to investigate the reaction mechanisms
linked with the oxy-fuel combustion of ethanol (C2H6O). The oxidation of ethanol in O2/N2 and O2/CO2 environments was examined using
reactive molecular dynamics in the temperature range from 2200 to
3000 K at constant density media and O2/fuel ratio equals
to 0.5. The main reactions were examined to supply a description of
the ethanol oxidation behavior, the main product distribution, and
the corresponding time evolution behavior in the atomic scale. It
has been noted that the oxidation of C2H6O was
initiated mainly from the same routes in both environments generating
the same main species. However, the key reaction pathways were different
depending on the media. We noticed an increase of CO formation when
N2 was replaced by CO2 molecules, increasing
the net flux of the following reactions: by CO2 + H →
CO + OH and CO2 + CHO → OCOH + CO. This
work also studied the effect of increasing O2 concentration
(O2/fuel ratio equals to 0.5, 1.0, and 2.0) in O2/CO2 combustion. During the simulations, high oxygenated
and unstable species were detected such as carbonates and carboxyl
radicals. The change of the O2/fuel ratio from 0.5 to 2.0
lead to an increase of CO2 formation mainly from O2 + OCOH → CO2 + HO2 and
O2 + CO → CO2 + O reactions. In addition,
the increase of O2 concentration attenuated the effect
of CO2 and could increase the occurrence of reactions that
lead to flame cessation.