Laminar burning velocity and interchangeability analysis of biogas/C3H8/H2 with normal and oxygen-enriched air

• The laminar burning velocity increases with the amount of oxygen in the oxidizer.
• Natural gas is interchangeable with the fuel mixture 50% biogas – 40% C3H8 – 10% H2.
• Addition of propane and hydrogen to biogas increases its burning velocity.
• The addition of oxygen to the oxidizer increases the reactivity of the mixture.

Numerical and experimental measurements of the laminar burning velocities of biogas (66% CH4 – 34% CO2) and a biogas/propane/hydrogen mixture (50% biogas – 40% C3H8 – 10% H2) were made with normal and oxygen-enriched air while varying the air/fuel ratio. GRI-Mech 3.0 and C1–C3 reaction mechanisms were used to perform numerical simulations. Schlieren images of laminar premixed flames were used to determine laminar burning velocities at 25 °C and 849 mbar. The mixture's laminar burning velocity was found to be higher to that of pure biogas due to the addition of propane and hydrogen. An increase in the laminar burning velocities of both fuels is reported by enriching air with oxygen, a phenomenon that is explained by the increased reactivity of the mixture. Additionally, an analysis of interchangeability based on both the Wobbe Index and the laminar burning velocity between methane and a biogas/propane/hydrogen mixture is presented in order to consider this mixture as a substitute for natural gas. It was found that the variations of these properties between the fuels did not exceed 10%, enabling interchangeability.