Towards An Ab initio Based Isomer Specific Cresol Sub-Mechanism
Researcher:
Carstensen , Hans-Heinrich
Congress:
CYPHER 1st General Meeting
Participation type:
Póster
Other authors:
Nicolas Delort, Olivier Herbinet, Frédérique Battin-Leclerc
Year:
2024
Location:
Ljubljana (Slovenia)
Lignin is an under-utilized major component of lignocellulosic biomass, which has the potential to be an important resource for renewable fuels. Due to the nature of lignin, depolimerization produces a large number of phenolic components. [1] In a recent presentation at the 15th international conference on Combustion Technologies for a clean environment [2], Meziane and coworkers presented laminar burning velocity (LBV) measurements for phenol and the cresol isomers together with a newly developed kinetic model called Colibri, which was assembled from validated sub-mechanism from the literature. The prediction underestimated the LBV for all four species, indicating that the current knowledge of the combustion of these phenolic species needs to be improved. Furthermore, the model treat cresol as a lumped species, hence does not provide any reactivity differentiation among the three isomers. On the other hand, the LBV results clearly showed notable differences among these isomers. While an early experimental and modelling study [3] on phenol pyrolysis and oxidation suggested that similar pathways would be operational, a recent theoretical study on phenol by Pratali Maffei et al. [4] indicate that in oxidation the role of arylic radicals formed through H abstraction from the aromatic ring should be more important than previously thought.
The current study has multiple objectives. First, to replace rate expressions for “lumped” cresol in the current version of the Colibri model with cresol isomers specific reactions and rate expressions. Second, additional chemistry relevant to the aryl radicals of phenol and cresol will be added. Finally, the updated kinetic model will be applied to the LBV experiments to test, if the modifications lead to improvements of the predictions in terms of quantitative LBVs and the relative differences seen for the four fuels
Lignin is an under-utilized major component of lignocellulosic biomass, which has the potential to be an important resource for renewable fuels. Due to the nature of lignin, depolimerization produces a large number of phenolic components. [1] In a recent presentation at the 15th international conference on Combustion Technologies for a clean environment [2], Meziane and coworkers presented laminar burning velocity (LBV) measurements for phenol and the cresol isomers together with a newly developed kinetic model called Colibri, which was assembled from validated sub-mechanism from the literature. The prediction underestimated the LBV for all four species, indicating that the current knowledge of the combustion of these phenolic species needs to be improved. Furthermore, the model treat cresol as a lumped species, hence does not provide any reactivity differentiation among the three isomers. On the other hand, the LBV results clearly showed notable differences among these isomers. While an early experimental and modelling study [3] on phenol pyrolysis and oxidation suggested that similar pathways would be operational, a recent theoretical study on phenol by Pratali Maffei et al. [4] indicate that in oxidation the role of arylic radicals formed through H abstraction from the aromatic ring should be more important than previously thought.
The current study has multiple objectives. First, to replace rate expressions for “lumped” cresol in the current version of the Colibri model with cresol isomers specific reactions and rate expressions. Second, additional chemistry relevant to the aryl radicals of phenol and cresol will be added. Finally, the updated kinetic model will be applied to the LBV experiments to test, if the modifications lead to improvements of the predictions in terms of quantitative LBVs and the relative differences seen for the four fuels