An updated detailed reaction mechanism for syngas combustion

Abstract

Detailed reaction mechanisms for syngas combustion are analyzed in the present work. The exhaustive list of reactions within different reaction mechanisms is summarized and the differences among these mechanisms are presented. Detailed comparisons of the contemporary choices of the reaction rate coefficients are analyzed in detail, and an updated reaction mechanism for syngas combustion together with the recommended rate coefficients with minimal uncertainties have been proposed. The importance of the listed reactions and their corresponding rate constant uncertainties are analyzed according to a detailed survey of the sources of the rate constants together with sensitivity analysis and rate-of-production (ROP) analysis. It is found that with the development of advanced experimental and computational methods, the rate constant uncertainties of a large number key reactions are minimized. However, large uncertainties still exist for hydrogen peroxide (H₂O₂) and hydroperoxyl radical (HO₂) related reaction sequences, which play a key role for syngas combustion at high-pressure and low-to-intermediate temperature conditions. The updated detailed mechanism is validated against standard targets, including ignition delay time and laminar flame speeds over a wide range of conditions. The present work not only provides an updated detailed mechanism for syngas combustion, but also provides fundamental information to further develop a universal core reaction mechanism which is the foundation to the development of combustion mechanisms of all the other hydrocarbon fuels.