Numerical Study on Emission Control and Burner Optimization in Hydrogen and Synthetic Micro Diffusion Flames

Hussien, Mahmoud Ashraf; Kayed, Hatem; Abou-Arab, Tharwat Wazeer; Ibrahim, Abdelmaged

doi:10.21608/ejchem.2025.347187.11036

Numerical Study on Emission Control and Burner Optimization in Hydrogen and Synthetic Micro Diffusion Flames

Document Type : Original Article

Authors

¹ Mechanical Power Engineering Department, Institute of Aviation Engineering and Technology, Giza, 12658, Egypt

² Mechanical Power Department, Faculty of Engineering, Cairo University, Cairo 12613, Egypt

10.21608/ejchem.2025.347187.11036

Abstract

This study investigates the environmental impacts of non-premixed hydrogen and synthetic micro-diffusion flames, focusing on minimizing harmful emissions and enhancing combustion efficiency. Numerical simulations were conducted to analyze CO elimination and NOx reduction using a reduced 61-step Deutschmann chemical reaction mechanism. The study also compared Deutschmann and GRI-MECH 3.0 chemical reaction mechanisms, confirming their similar emission predictions, with the Deutschmann mechanism showing slightly better alignment with experimental data. The thermal interaction between the flame and burner was evaluated under varying burner materials and fuel flow velocities, emphasizing emission control and energy conservation. The findings reveal that an optimal case of using low conductive titanium burner and low fuel flow ejecting velocity for pure hydrogen diffusion flame, results in the highest energy saving by increasing the maximum flame temperature and length by 2.24% and 7.69%, respectively, when compared to the case of high conductive copper burner at the same fuel velocity. However, using titanium burner increases NOx levels by 58% compared to copper burner due to higher flame temperatures and maximal heat release rates. In contrast, higher fuel flow velocities weaken the thermal interaction between the flame and burner, resulting in consistent flame structure and emissions regardless of burner material, with no significant energy-saving benefits. Furthermore, the effects of hydrocarbon mixing with hydrogen on flame characteristics revealed that synthetic fuel flames exhibit 15.98% longer structures and 0.76% lower maximum temperature compared to pure hydrogen flames, indicating a reduction in thermal NOx emissions. This optimal configuration promotes a balanced approach to energy saving, and emission control.

Keywords