A comprehensive review of aluminum gas-phase combustion kinetics in oxygen and steam environments

Aluminum (Al), as a carbon-free energy source and energy carrier, features favorable characteristics regarding its production, transportation, utilization, and recyclability. However, the understanding of Al gas-phase combustion kinetics is still limited. The novelty of this work lies in presenting the first detailed and comprehensive analysis of the Al gas-phase mechanism in the air and steam environments. Kinetic mechanisms from open literature are analyzed on an elementary reaction level and a mechanism global performance level. On an elementary reaction level, critical reactions outlining the major reaction pathways are reviewed, and their rate constants from both experimental measurements and theoretical calculations are compared. On a mechanism global performance level, different mechanisms are evaluated in a custom-developed Computational Fluid Dynamics (CFD) model to characterize the flame structure of a steadily burning Al droplet. Results reveal that rate constants vary by more than 5 orders of magnitude among the mechanisms. The predicted species and temperature profiles also differ significantly. In particular, the temperature profiles can vary by ∼ 1000 K, with sensitivity primarily to the rate at which the reaction progresses toward . An overall trend in reaction progress rates was observed, with the Storozhev mechanism being the fastest, followed by the Glorian, Saba, and Starik mechanisms. Although experimental validation and quantum chemistry analysis are still limited, this work provides a valuable foundation for both chemical kinetic modelers to further improve and unify the Al mechanisms and CFD modelers to identify a proper mechanism based on their applications. • The aluminum gas-phase combustion kinetics are comprehensively reviewed and evaluated for the first time. • Crucial elementary reactions and their rate constants are scrutinized using literature data and a custom-developed CFD model. • Quantification of heat release and major species profiles among various mechanisms is illustrated. • Suggestions are made for future research on Al combustion kinetics, and for the appropriate selection of mechanisms for CFD simulations.