Theoretical Studies on Isomerization and Decomposition Reactions of 2-Methyl-1-butanol Radicals

Abstract

2-Methyl-1-butanol (2M1B) is a favorable candidate of substitute fuels characterized with high energy density and low hygroscopicity. 2M1B radicals, which are the products of H-abstraction reactions of 2M1B, and their isomerization and decomposition reactions play a cardinal impact on the distribution of combustion products. In this work, the primary isomerization and decomposition reaction channels of 2M1B radicals were investigated by using QCISD(T)/CBS//M062x/cc-pVTZ and CBS-QB3 method, respectively. The accurate phenomenological temperature-and pressure-dependent rate constants covering temperatures of 250−2500 K and pressures from 1 × 10 −3 to 1 × 10 3 bar along with high-pressure limit rate constants for these channels were computed by solving the RRKM/master equation. The calculations revealed that the isomerization reaction of RC2 → RC6 has the highest energy barrier among these reactions, while the decomposition reaction RC6 → CH 3 CH 2 CHCH 3 + CH 2 O has the lowest energy barrier. Furthermore, the computed rate coefficients were also validated by using the previous pyrolysis experiment. The modeling results reproduce the experimental results satisfactorily. The current work not only provides reasonable kinetic data for the development of 2M1B combustion models but also lays a foundation to extend the kinetic mechanisms of alcohol with a longer chain.

Theoretical study on iso‐pentanol oxidation chemistry: Fuel radical isomerization and decomposition kinetics and mechanism development

“…With regards to decomposition kinetics, the reactions involving the cleavage of C‐C and C‐O bonds are the most favorable decomposition channels, featuring lower potential barriers than those involving C‐H bond cleavage. These findings are in line with similar observations proposed in previous studies on pentanol oxidation isomers, such as n‐pentanol, 27 2‐pentanol, 52 and 2‐methyl‐1‐butanol 53 …”

“…These findings are in line with similar observations proposed in previous studies on pentanol oxidation isomers, such as n-pentanol, 27 2-pentanol, 52 and 2-methyl-1-butanol. 53…”

Theoretical investigation on isomerization and decomposition reactions of pentanol radicals-part I: branched pentanol isomers

“…The rate constants of the H-atom abstraction reaction were obtained through variational transition state theory, and the effect of hydrogen bonds on kinetics was also investigated. Zhong et al 24 investigated the isomerization and decomposition reaction channels of 2-methyl-1-butanol radicals by using QCISD(T)/CBS//M06-2X/cc-pVTZ methods.…”