Numerical investigation of the potential of using hydrogen as an alternative fuel in an industrial burner

This study investigates hydrogen and hydrogen-methane mixtures as alternative fuels for industrial burners, focusing on combustion dynamics, flame stability, and emissions. CFD simulations in ANSYS Fluent utilized the RANS framework with the k-epsilon turbulence model and the mixture fraction/PDF approach. Supporting Python scripts and Cantera-based kinetic modeling employing the GRI-Mech 3.0 mechanism and Zeldovich pathways analyzed equivalence ratios (Phi), adiabatic flame temperatures (T-ad), and NOx formation mechanisms. Results revealed non-linear temperature trends, with a 50 % hydrogen blend yielding the lowest peak temperature (1880 K) and a 75 % hydrogen blend achieving optimal performance, balancing peak temperatures (similar to 1900 K), reduced NOx emissions (5.39 x 10(-6)), and near-zero CO2 emissions (0.137), though flame stability was impacted by rich mixtures. Pure hydrogen combustion produced the highest peak temperature (2080 K) and NOx emissions (3.82 x 10(-5)), highlighting the need for NOx mitigation strategies. Mass flow rate (MFR) adjustments and excess air variation significantly influenced emissions, with a 25 % MFR increase reducing NOx to 2.8 x 10(-5), while higher excess air (e.g., 30 %) raised NOx under lean conditions. Statistical analysis identified Phi, hydrogen content (H-2%), and flame stability as key factors, with 50 %-75 % hydrogen blends minimizing emissions and optimizing performance, emphasizing hydrogen's potential with controlled MFR and air adjustments.