6 research outputs found
Kinetic Modeling of α‑Hydrogen Abstractions from Unsaturated and Saturated Oxygenate Compounds by Hydrogen Atoms
Hydrogen-abstraction reactions play
a significant role in thermal
biomass conversion processes, as well as regular gasification, pyrolysis,
or combustion. In this work, a group additivity model is constructed
that allows prediction of reaction rates and Arrhenius parameters
of hydrogen abstractions by hydrogen atoms from alcohols, ethers,
esters, peroxides, ketones, aldehydes, acids, and diketones in a broad
temperature range (300–2000 K). A training set of 60 reactions
was developed with rate coefficients and Arrhenius parameters calculated
by the CBS-QB3 method in the high-pressure limit with tunneling corrections
using Eckart tunneling coefficients. From this set of reactions, 15
group additive values were derived for the forward and the reverse
reaction, 4 referring to primary and 11 to secondary contributions.
The accuracy of the model is validated upon an ab initio and an experimental
validation set of 19 and 21 reaction rates, respectively, showing that
reaction rates can be predicted with a mean factor of deviation of
2 for the ab initio and 3 for the experimental values. Hence, this
work illustrates that the developed group additive model can be reliably
applied for the accurate prediction of kinetics of α-hydrogen
abstractions by hydrogen atoms from a broad range of oxygenates