Experimental investigations on laminar burning velocity variation of CH4+H2+air mixtures at elevated temperatures

The present work reports experimental investigations on laminar burning velocity variation of CH4+H-2+air mixtures at elevated temperatures (300-650 K) using an externally heated diverging-channel method. The effect of mixture equivalence ratio (phi = 0.7-1.3) and H2 fraction (0-50% by volume) on burning velocity have been reported at elevated temperatures. The experimental measurements are compared with numerical simulations using GRI Mech 3.0 and FFCM-1 kinetic models. The obtained results exhibit an increase in the laminar burning velocity with H2 fraction due to the formation of H-atom as an intermediate. The temperature dependency is established through a power-law correlation. The temperature-exponent shows a parabolic variation with a minimum value at phi = 1.1. Reaction pathway diagram interprets the major oxidation paths followed by reactants for higher carbon-consumption with varying H-2 fraction. The P2 pathway involving ethane breakdown plays a major role in enhancing the burning velocity at rich mixture conditions. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the laminar burning velocity variation of CH4+H-2+air mixtures at elevated temperatures using an externally heated diverging-channel method. Results showed an increase in burning velocity with higher H2 fraction due to the formation of H-atom as an intermediate, establishing a temperature dependency through a power-law correlation.