A Comprehensive Kinetic Modeling of Ignition of Syngas–Air Mixtures at Low Temperatures and High Pressures

Abstract

Syngas has gained increasing attention due to the possibility that it is produced by coal and biomass. In order to develop more efficient processes suitable for different combustion conditions, a study of the kinetic of syngas ignition was carried out. Several kinetic mechanisms present in the literature were compared with experimental data. Different conditions were investigated, including various parameters such as temperature, pressure, and composition. H₂O₂ + M = OH + OH + M and H + H₂O₂ = HO₂ + H₂ have been found to be dominant in the prediction of ignition times by a sensitivity analysis. Enhancements to the kinetic mechanism have been carried out by splitting the reactions in forward and backward reactions, and by adjusting values of the rate constants in the range of confidence of their evaluation. The new mechanism is able to predict quite well the behavior of syngas in all conditions examined, particularly in gas turbine conditions. Moreover, the influence of pressure and of CO concentration have been investigated with the new enhanced kinetic mechanism.

Keywords:

• Autoignition
• Gas turbine
• Kinetic mechanism
• Syngas