Amirkabir University of Technology AUT Journal of Mechanical Engineering 2588-2937 7 4 2023 12 01 Exploring Flame Characteristics of CH4/CO2/Ammonia/Air Mixtures under Elevated Conditions: An Interferometry-Based Investigation 389 418 5472 10.22060/ajme.2024.23011.6092 EN Mehrdad Kiani Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran Ali Akbar Abbasian Arani Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran 0000-0003-3011-0297 Mehdi Ashjaee School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran Ehsan Houshfar School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran Journal Article 2024 02 23 Ammonia (<em>NH₃</em>) stands out as a leading option for large-scale renewable energy storage and long-distance transportation. By incorporating landfill gas and raising initial reactant temperatures, <em>NH₃</em> reactivity is effectively enhanced in gas turbines and boilers. This study focuses on exploring the laminar flame propagation of <em>NH₃</em>/landfill mixtures under elevated conditions. Accurate predictions for laminar burning velocity were achieved through numerical simulations employing Ansys Chemkin-Pro, along with the San Diego, Okafor, and GRI-Mech 3.0 mechanisms. Elevating pressure from 1 to 10 bar resulted in a reduction in laminar burning velocity from 16.1 to 6 cm/s, ultimately leading to an increase in adiabatic flame temperature from 2102 to 2143 attributable to changes in combustion equilibrium. Also, the results underscored the significant influence of ammonia concentration on augmenting laminar burning velocities. In cases with higher laminar burning velocity, the proportion of <em>NH₃</em> added tends towards zero, while in cases with lower laminar burning velocity, the addition ratio of <em>NH₃</em> tends towards one. The addition of ammonia leads to a reduction in the pool of radicals. Put simply, because ammonia has a lower laminar burning velocity, the overall Laminar burning velocity of the mixture is reduced as the concentration of ammonia in the fuel mixture increases. https://ajme.aut.ac.ir/article_5472_64c26b2a2dcf068c49894bd07e0e6389.pdf