Experimental and modelling study of phenol combustion and oxidation

Abstract

Despite of its central importance in the chemistry of aromatic compounds and fuels derived from biomass, only few experimental studies on phenol combustion can be found in literature. In this paper, unique measurements of the adiabatic laminar burning velocities of phenol are presented, together with the first experimental study of the oxidation of this molecule in a jet-stirred reactor. The burning velocities were measured with a flat-flame burner using the heat-flux method for a fresh gas temperature of 398 K and equivalence ratios from 0.7 to 1.35. In the reactor experiments, the oxidation of a stoichiometric mixture of phenol highly diluted in helium was investigated at temperatures between 600 and 1100 K at near-atmospheric pressure. The mole fraction of the reactants, as well as 32 products, mainly carbon monoxide, carbon dioxide, methane, acetylene ethylene, acrolein, cyclopentadiene, benzene, naphthalene and dibenzofuran, were recorded.Based on previous literature work, a new detailed kinetic model is developed based on several published sub-mechanisms and updated considering rate constants taken from recent literature studies or calculated at the CBS-QB3 or G4 level of theory. This model leads to a significantly improved prediction of the phenol burning velocities compared to literature models, as well as a reasonable prediction of most species mole fractions during phenol oxidation in the jet-stirred reactor. Sensitivity analyses as well as flow rate analyses are discussed to explain the obtained model improvements.