A study on thermal combustion of lean methane-air mixtures: Simplified reaction mechanism and kinetic equations

Homogeneous combustion of lean methane-air mixtures occurs in both thermal and catalytic reverse-flow reactors. The modeling and design of such reactor requires a reliable and relatively simple kinetic model of the combustion. Although a number of detailed descriptions of the kinetics of homogeneous combustion are available in the literature (including those which take into account complex free-radical reactions), their practical usefulness is doubtful. In the present study a simple one- or two-stage model is proposed which directly describes global kinetics and neglects intermediates and radicals. Special attention is paid to the mechanism of the possible formation of carbon monoxide. The studies were done both for the combustion in the free space and for the process taking place over a monolith packing. (C) 2009 Elsevier B.V. All rights reserved.