Study of the Low Temperature Oxidation of Propane

The low-temperature oxidation of propane was investigated using
a jet-stirred reactor at atmospheric pressure and two methods of analysis:
gas chromatography and synchrotron vacuum ultraviolet photoionization
mass spectrometry (SVUV-PIMS) with direct sampling through a molecular
jet. The second method allowed the identification of products, such
as molecules with hydroperoxy functions, which are not stable enough
to be detected by gas chromatography. Mole fractions of the reactants
and reaction products were measured as a function of the temperature
(530–730 K), with a particular attention to reaction products
involved in the low temperature oxidation, such as cyclic ethers,
aldehydes, alcohols, ketones, and hydroperoxides. A new model has
been obtained from an automatically generated one, which was used
as a starting point, with a large number of re-estimated thermochemical
and kinetic data. The kinetic data of the most sensitive reactions,
i.e., isomerizations of alkylperoxy radicals and the subsequent decompositions,
have been calculated at the CBS-QB3 level of theory. The model allows
a satisfactory prediction of the experimental data. A flow rate analysis
has allowed highlighting the important reaction channels.