Single iron particle combustion - A morphology study of partially oxidized iron particles

In recent years, metal fuels were discussed as a contribution to meeting the challenges of the energy transition to
a climate-friendly, sustainable energy economy. One material system with high potential to store and release a
large amount of energy is iron powder and its reducible solid product iron oxide powder. In this study, the
evolution of the particle morphology during single particle combustion in a laminar flow reactor is analyzed.
Partially oxidized iron particles are sampled at different heights above the burner and their internal morpho-
logical structure is revealed qualitatively and quantitatively by tomography and microscopy methods (μCT, SEM,
EDX, EBSD). The findings show that interfacial phenomena might play a major role when describing single
particle combustion as the existence of two liquid phases with emulsification phenomena can be detected. Based
on the results, a morphological description of the oxidation progress is proposed within the frame of this work.