Measurements of the Laminar Burning Velocities for Typical Syngas–Air Mixtures at Elevated Pressures

In the currently reported work, three typical mixtures of H₂, CO, CH₄, CO₂, and N₂ have been considered as representative of the producer gas (syngas) coming from biomass gasification. Syngas is being recognized as a viable energy source worldwide, particularly for stationary power generation. However, there are gaps in the fundamental understand of syngas combustion characteristics, especially at elevated pressures that are relevant to practical combustors. In this work, constant volume spherical expanding flames of three typical syngas compositions resulting from biomass gasification have been employed to measure the laminar burning velocities for pressures ranges between 1.0 and 20 bar tanking into account the stretch effect on burning velocity. Over the ranges studied, the burning velocities are fit by a functional form $Su=Su0(T/T0)α(P/P0)β$⁠; and the dependencies of α and β upon the equivalence ratio of mixture are also given. Conclusion can be drawn that the burning velocity decreases with the increase of pressure. In opposite, an increase in temperature induces an increase of the burning velocity. The higher burning velocity value is obtained for downdraft syngas. This result is endorsed to the higher heat value, lower dilution and higher volume percentage of hydrogen in the downdraft syngas.