Iron powder combustion stands out as a promising avenue for sustainable energy storage, owing to its high energy density compared to conventional systems [1]. This process involves the exothermic oxidation of iron powder, followed by its regeneration using sustainable energy sources, to obtain a zero CO2 cycle [1]. While promising, only pure iron has been considered up to now for this application. However, impurities such as manganese can be expected in low cost iron as it is one of the major impurities found in iron ores [2] as well as in recycled steels [3]. Using low purity iron would increase the economic competitiveness of this energy carrier and accelerate the transition from fossil fuels to sustainable energy production.

Figure 1. Energy density and specific energy of energy storage systems. Adapted from Bergthorson et al. [1].

While very promising, iron combustion still presents several challenges such as micro-explosions, crack formation, nanoparticles and NOx emission [4]. The presence of impurities, and in particular of manganese, will impact the oxidation process and could be the solution of the currently faced challenges during iron combustion.

In this study, the influence of manganese on the combustion of Fe-based powder is investigated through a detailed analysis of the combustion products obtained for different initial Mn content. The morphology, microstructure, phase distribution and local chemistry are investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The presence and chemistry of the nanoparticle emitted are studied using transmission electron microscopy (TEM). This research focusses on the interplay between the local chemistry and the thermo-physical phenomena activated during the combustion of Fe-Mn fuel.

References

[1] J.M. Bergthorson, S. Goroshin, M.J. Soo, P. Julien, J. Palecka, D.L. Frost, D.J. Jarvis, Applied Energy, (2015), 160, 368–382.

[2] Ye. Samuratov , A. Baisanov , M. Tolymbekov , The Twelfth International Ferroalloys Congress Sustainable Future (2010)

[3] O. Hajime, K. Yasushi M. Kazuyo, T. Osamu, M. Takahiro, N. Shinichiro, N. Tetsuya, Environmental Science & Technology (2013),10.1021/es3043559

[4] D.Ning, Y. Shoshin, J.A Van Oijen, G. Finotello, L.P.H de Geoy, Flame (2021), 230, 111424