Theoretical and kinetic modelling study of phenol and phenoxy radical decomposition to CO and C5H6/C5H5 in pyrolysis conditions
Main Authors: | Pratali Maffei, Luna, Pelucchi, Matteo, Faravelli, Tiziano, Cavallotti, Carlo |
---|---|
Format: | Proceeding |
Bahasa: | eng |
Terbitan: |
, 2019
|
Online Access: |
https://zenodo.org/record/3587939 |
Daftar Isi:
- Bio-oils from biomass fast-pyrolysis are an economically viable solution to reduce carbon footprint [1]. Lignin-derived bio-oils are a complex mixture of oxygenated species, including phenolic compounds such as phenol, anisole, guaiacol, catechol and vanillin (20-30% in weight) [2]. Hence, an accurate characterization of the pyrolysis and combustion kinetics of phenolic species, starting from phenol, is essential to assess the technical viability of these biooils. Furthermore, phenol plays a key role in the mechanism of oxidation of benzene, a building block of PAHs chemistry, precursors of soot and PM [3]. Finally, substituted phenolic species have recently gained attention for their antiknock properties and are being considered as possible octane boosters [4]. Nevertheless, the kinetics of phenol has not been systematically addressed yet, and the available experimental data are limited. Therefore, a theoretical approach for the prediction of accurate kinetics provides a major contribution to improve the current knowledge. This work investigates with ab initio methods the two main decomposition pathways of phenol: 1) the molecular pathway forming C5H6+CO, and 2) the radical pathway forming C6H5O+H. This latter pathway justifies the additional investigation of the decomposition of phenoxy radical (C6H5O) to CO and cyclopentadienyl (C5H5). For a consistent investigation of phenol kinetics, also the H-abstraction reactions from cyclopentadiene are included. The kinetic constants thus obtained are included in the CRECK kinetic model and validated with experimental data.