Effect of Hydrogen Content and Dilution on Laminar Burning Velocity and Stability Characteristics of Producer Gas-Air Mixtures

Abstract EN

Producer gas is one of the promising alternative fuels with typical constituents of H2, CO, CH4, N2, and CO2.

The laminar burning velocity of producer gas was computed for a wide range of operating conditions.

Flame stability due to preferential diffusional effects was also investigated.

Computations were carried out for spherical outwardly propagating flames and planar flames.

Different reaction mechanisms were assessed for the prediction of laminar burning velocities of CH4, H2, H2-CO, and CO-CH4 and results showed that the Warnatz reaction mechanism with C1 chemistry was the smallest among the tested mechanisms with reasonably accurate predictions for all fuels at 1 bar, 300 K.

To study the effect of variation in the producer gas composition, each of the fuel constituents in ternary CH4-H2-CO mixtures was varied between 0 to 48%, while keeping diluents fixed at 10% CO2 and 42% N2 by volume.

Peak burning velocity shifted from ϕ=1.6 to 1.1 as the combined volumetric percentage of hydrogen and CO varied from 48% to 0%.

Unstable flames due to preferential diffusion effects were observed for lean mixtures of fuel with high hydrogen content.

The present results indicate that H2 has a strong influence on the combustion of producer gas.