Shock tube and multi-species laser absorption measurements of rate constants for methanol pyrolysis

Abstract

Quantitative and high-accuracy measurements of multiple rate constants regarding the reaction kinetics of methanol pyrolysis were performed in shock tube experiments over 1200 - 1610 K, 0.72 - 4.50 atm. The key reactions investigated include both the thermal dissociation of methanol and its major fragments (for example, CH2OH and CH3O), and their H-abstraction by H and CH3 radicals. Laser absorption time-histories of CH2O, CO and H2O were measured and analyzed with a Bayesian approach for systematic determination of the joint posterior distribution of their rate constants, using FFCM-1 as the base mechanism. Various types of uncertainty sources in the current measurements, including both the non-ideal effects in the shock tube and uncertainties in the mixture composition and the absorption model, were thoroughly analyzed. A comparative analysis using other reaction models was also briefly discussed.