Effects of CO₂ Dilution and CH₄ Addition on Laminar Burning Velocities of Syngas at Elevated Pressures: An Experimental and Modeling Study

Variations in biomass-derived syngas composition can be a challenge to efficient combustion and low emissions. A study on the effects of CO2 dilution CH4 addition flame propagating characteristics at high pressure was conducted using heat flux method kinetic simulations. This paper presents laminar burning velocity, SL H2/CO/CO2/O2/diluent mixtures H2/CO/CH4/O2/diluent ϕ = 0.5–2.5, elevated pressures one-11 atm H2–CO mole fraction ratios 0.25:0.75 0.75:0.25. The fuel (from 0.0 0.4), CH4/(CH4+CO) 1.0), dependence were experimentally investigated compared simulated results from three mechanisms. increase hydrogen fraction, or decrease fuel, both lead an SL; decreased enhanced significantly more over-rich conditions. dilution, thermal-diffusion, chemical (including direct reaction three-body effects) quantitively distinguished different H2 contents. showed that increasing competition H consuming reactions, retarding effect found favored content Both overall order flames by decreasing adiabatic temperature. Increasing increased release rate enhancing collision reactions enrichment radical, their reversed speed.