Numerical analysis of the combustion in a micromix-type burner operating with hydrogen-natural gas blends

• Numerical simulations of a Micromix burner for hydrogen and natural gas mixtures were accomplished. • Three different reaction mechanisms were tested, GRI-Mech 3.0 is the most accurate. • The study explores various hydrogen and natural gas mixtures with several equivalence ratios. • Key indicators, as CO 2 equivalent emissions, the Wobbe and Weaver index were analyzed to assess mixture interchangeability. The shift to hydrogen as an energy carrier holds promise for addressing industrial decarbonization in critical sectors. With a focus on cleaner and more efficient energy sources, this research delves into the analysis of a Micromix burner through numerical simulations, evaluating three reaction mechanisms: GRI-Mech 3.0, hydrogen/air, and San Diego. Validation of numerical simulations based on combustion chamber outlet temperature reveals GRI-Mech 3.0 as the most accurate, with an average relative error of 1%. Further validation against Sandia laboratory experimental data solidifies the choice of GRI-Mech 3.0 for numerical modeling of the Micromix burner for both hydrogen and natural gas. The study explores various hydrogen and natural gas mixtures with several equivalence ratios, considering indicators like temperature profile analysis, Wobbe index, Weaver index, unburned emissions, heat release rate, flame length, flame temperature and C O 2 -equivalent emissions. This research contributes valuable insights into computational fluid dynamics (CFD) and Micromix burners, shedding light on the feasibility and efficiency of burners designed for hydrogen and natural gas mixtures. The findings are essential to advancing the transition to cleaner energy sources and laying a solid foundation for optimizing micromix burners.