Auto-ignition characteristics of oxygenated aromatic compounds: Benzyl alcohol, benzaldehyde, and phenol

• Published in: Proceedings of the Combustion Institute 2024, Vol.40 (1-4), p.105252, Article 105252
• Main Authors: Heufer, Karl Alexander, Büttgen, Rene Daniel, Pratali Maffei, Luna, Pelucchi, Matteo
• Format: Article
• Language: English
• Subjects: Benzaldehyde; Benzyl alcohol; Ignition delay; Kinetic model; Oxygenated aromatics; Phenol
• ISSN: 1540-7489
• DOI: 10.1016/j.proci.2024.105252

The growing attention towards biomass and biomass-derived fuels for transportation, energy production, forest fire prevention, and safety applications stimulated significant research activities focused on understanding the chemical kinetics of oxygenated aromatic hydrocarbons, which represent important reference components for biofuels. This motivates the current investigation of the ignition behavior of benzyl alcohol, benzaldehyde, and phenol, which exhibit intertwined reaction pathways. Novel ignition delay time data were measured in a shock tube and a rapid compression machine covering pressures from 10 to 40 bar and temperatures from 860–1250 K. In addition, a kinetic model was developed and used to analyze critical reaction pathways in comparison to models from literature. It is shown that the phenyl-phenoxy-phenyl peroxy subsystem plays a key role not only in the oxidation of benzaldehyde, but also in the oxidation of benzene and phenol. Comparison of the current model with a recent version of the CRECK mechanism reveals that differences are present with respect to the dominant reaction pathways that have a strong influence on the formation of Ö radicals. Further investigations are required to resolve this discrepancy reconciling theory, modelling, and the unfortunately limited number of systematic experimental data to which this work significantly contributes.