Oxygen-Enriched Combustion of Alternative Fuels

Dear Colleagues,

The transition toward low-carbon and carbon-neutral energy systems has accelerated research into alternative fuels such as hydrogen, ammonia, biofuels, and synthetic fuels. Among the various strategies to enhance the efficiency and stability of these fuels, oxygen-enriched combustion has emerged as a promising approach. By increasing the oxygen concentration in the oxidizer stream, this technique can significantly improve flame stability, combustion efficiency, and heat release characteristics, while also enabling compact combustor designs and reducing pollutant emissions under certain conditions. Oxygen-enriched combustion is particularly relevant for fuels with inherently low reactivity or poor flame stability, such as ammonia. These fuels often suffer from narrow flammability limits, low burning velocities, and high ignition energy requirements. Oxygen enrichment can help overcome these limitations, making it a key enabling technology for practical applications. However, the process also introduces new challenges, including increased flame temperatures, enhanced formation of nitrogen oxides (NO_x), and material durability concerns. Therefore, a comprehensive understanding of the underlying combustion physics, chemical kinetics, and transport processes is essential. (2) Aim of the Special Issue and how the subject relates to the journal scope. This Special Issue aims to provide a comprehensive platform for advancing the fundamental and applied understanding of oxygen-enriched combustion of alternative fuels. It seeks to bring together contributions from experimental, numerical, and theoretical studies that address key challenges and opportunities in this field. The topic aligns closely with the journal’s scope in combustion science, energy engineering, and environmental sustainability. By focusing on both fundamental mechanisms and practical applications, this Special Issue will support the development of cleaner and more efficient combustion technologies. It is particularly relevant to emerging energy systems, such as gas turbines, industrial furnaces, and propulsion systems, where alternative fuels and oxygen-enriched conditions are increasingly being considered (3) Suggested themes and article types for submissions. Potential topics for submission include, but are not limited to: Fundamental studies of flame structure, ignition, extinction, and stability under oxygen-enriched conditions Combustion characteristics of alternative fuels (e.g., hydrogen, ammonia, biofuels, and fuel blends) Chemical kinetics and reaction mechanisms in oxygen-enriched environments Pollutant formation and mitigation strategies, particularly NO_x emissions Effects of preferential diffusion and diffusive–thermal instabilities High-pressure and high-temperature combustion behavior Advanced diagnostic techniques and optical measurements Numerical simulations, including DNS, LES, and reduced-order modeling Design and optimization of combustors using oxygen-enriched combustion Industrial applications and scale-up challenges. Both original research articles and review papers are welcome. Short communications and perspective articles that highlight emerging trends or novel concepts are also encouraged.

Dr. Yu Xia
Dr. Xinhua Zhang
Dr. Zhenhua An
Guest Editors

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• oxygen-enriched combustion
• alternative fuels
• ammonia combustion
• hydrogen combustion
• flame stability and extinction
• chemical kinetics
• nitrogen oxides (NO_x) emissions
• high-temperature combustion
• combustion diagnostics
• numerical simulation