Numerical study of the effect of hydrogen addition on the laminar flame speed and premixed flame structure of biogas

In this work, the laminar flame speed and flame structure of biogas/H2 fuel mixtures were studied numerically from pure biogas to biogas with an addition of 15% H2 in volume by using the CHEMKIN software with the GRIMECH 2.11 kinetic mechanism. The effect of hydrogen addition to biogas on laminar flame speed and flame structure has been studied as well as the variation of the aeration rate from stoichiometric conditions to lean conditions. The trends in laminar flame speed results obtained are explained by means of numerical results on temperature profile and heat release rate. CO, CO2 and NO profiles are also observed for the different mixtures studied. Hydrogen addition in biogas flames shows an important effect, especially in zones near stoichiometric flames, decreasing its effects in lean mixtures combustion.