A shock tube study of CH3OH + OH → Products using OH laser absorption

Abstract

The rate coefficient for the reaction of methanol (CH3OH) with the hydroxyl (OH) radical was determined in reflected shock wave experiments at temperatures of 961–1231K and pressures of 1.18–1.48atm. Pseudo-first order reaction conditions were achieved with mixtures of CH3OH and tert-butyl hydroperoxide (TBHP) diluted in argon. Rapid thermal decomposition of TBHP at high temperatures was used as a fast OH radical source, and OH time-histories were measured using laser absorption of OH radicals near 306.7nm. The rate coefficient of the title reaction was found from best-fit comparison of simulated OH profiles with measured data, using simulations from the Wang et al. USC-Mech II reaction mechanism (2007). A detailed uncertainty analysis was performed, with estimated uncertainties of −10%/+17% at 961K and −12%/+18% at 1231K. The current results agree well with the results of Vandooren and Van Tiggelen (1981), Hess and Tully (1989), and Xu and Lin (2007). The three-parameter Arrhenius expression k1(210–1231K)=5.71×104T2.62exp(343/T[K]) cm3mol−1s−1 is recommended from a fit to the combined data of Hess and Tully (1989), Jiménez et al. (2003), Dillon et al. (2005), and the current work.