A dimensionally reduced reaction mechanism for methanol oxidation

Abstract

Methanol has potential as an alternative fuel due to favorable combustion properties that include lower emissions of particulates and oxides of nitrogen. Disadvantages include high miscibility with water and potential difficulties with emissions of oxygenated species. Theoretical investigations of methanol oxidation in practical (e.g., turbulent and/or multidimensional) flow fields require chemistry descriptions that balance thermochemical fidelity, compactness, and mathematical properties (e.g., “stiffness”). Recent studies of methane combustion in turbulent flames have shown, through the application of augmented (large scalar space) reduced reaction mechanisms, that accurate chemistry is a prerequisite for quantitative predictions of kinetically influenced phenomena. The latter include extinction/reignition and pollutant emissions. The present work extends past work on augmented reduced mechanisms to include methanol oxidation. The detailed and systematically reduced mechanisms are comprehensively validated against shock tube, flow reactor, premixed, and partially premixed flame data. It is shown that the detailed starting mechanism featuring 52 species and 326 reactions can be reduced to a 14-step mechanism for the C/H/O system and a 5-step submechanism for nitrogen-containing species without appreciable lack of generality.