The first experimental evidence of a solid-gas multiphase rotating detonation engine. Coal particles, carbon black with a volatility of 1% and a carbon concentration of 99%, were detonated successfully over many operational parameters. These operational parameters surrounding the various points of investigation are shown in multiple 2-D slices as well as plotted in one 3-D graph to show the effects of varying carbon concentrations. These parameters include: variation in total mass flux injected into the annulus ranging from (≅120–270 kg/(s*m2), variation in hydrogen-air equivalence ratio (0.65–1.0), and finally variation in total concentrations of carbon (0–42.5%). High-speed backend imaging allowed for the analysis of the detonation wave dynamics, where detonation velocities were deduced using Discrete Fourier Transforms. By varying the parameters mentioned above, detonation velocities experienced in the detonation channel allowed for an introduction of an optimal operational point. When carbon was injected into very lean hydrogen-air conditions, the detonation was over-driven, causing fluctuations in the detonation velocities upwards of ∼100 m/s. As carbon concentrations increased further, detonation wave velocities relative to Chapman-Jouguet detonation velocities decreased.