Ammonia Based Fuels: Combustion and Emission Behavior

Dear Colleagues,

The global transition toward low-carbon and carbon-free energy systems has intensified interest in alternative fuels that can support decarbonization across power generation, transportation, and industrial sectors. Among the emerging candidates, ammonia (NH₃) has gained significant attention as a promising hydrogen carrier and carbon-free fuel due to its established production infrastructure, high hydrogen density, and ease of storage and transport under moderate conditions. Unlike hydrogen, ammonia can be liquefied at relatively mild pressures, making it attractive for large-scale energy logistics and long-distance fuel supply chains.

Despite these advantages, the utilization of ammonia as a fuel introduces substantial scientific and engineering challenges, particularly in the context of combustion and fire safety. Ammonia exhibits inherently low reactivity, characterized by high ignition temperatures, low laminar flame speeds, and narrow flammability limits. Its combustion chemistry is further complicated by fuel-bound nitrogen pathways, which lead to the formation of nitrogen oxides (NOx and N₂O), raising both environmental and regulatory concerns. These characteristics significantly influence ignition, flame stabilization, extinction behavior, and overall combustion efficiency under practical conditions.

Recent advances in experimental diagnostics, chemical kinetics modeling, and computational fluid dynamics have significantly improved the ability to describe ammonia combustion processes. However, key gaps remain in linking fundamental combustion behavior with large-scale fire dynamics and real-world safety scenarios. This includes challenges in accurately predicting ignition under turbulent conditions, quantifying fire hazards in accidental releases, and developing reliable mitigation and suppression strategies.

Given the rapid emergence of ammonia as a viable energy vector, there is a pressing need to consolidate current knowledge and address unresolved issues at the intersection of combustion science and fire safety. This Special Issue is therefore timely, aiming to provide a comprehensive platform for advancing both the fundamental understanding and practical implications of ammonia combustion in fire-relevant environments.

This Special Issue aims to advance the fundamental understanding and applied knowledge of ammonia combustion and its applications as ammonia emerges as a promising carbon-free energy carrier. The Special Issue seeks to bring together cutting-edge experimental, numerical, and theoretical research that addresses ammonia combustion across multiple scales—from fundamental reaction kinetics and laminar flame studies to large-scale fire dynamics, safety assessments, and industrial applications. Contributions are encouraged that improve predictive understanding of ammonia combustion behavior, quantify fire and explosion risks, and propose mitigation strategies for safe utilization in energy systems such as engines, gas turbines, storage facilities, and transport infrastructure.

Suggested themes and article types for submissions:

1. Fundamental combustion characteristics;
2. Chemical kinetics and reaction mechanisms;
3. Flame dynamics;
4. Modeling and simulation;
5. Emissions and environmental impact.

Article Types:

1. Original research articles;
2. Review articles.

Dr. Anand Shankar Singh
Dr. Debojit Sharma
Dr. Rohit Kumar
Guest Editors

Manuscript Submission Information

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• ammonia combustion
• alternative fuels
• carbon-free fuel
• hydrogen carrier
• NOx emission
• gas turbines, IC engines, and industrial furnaces