Application of a validated gasification model to determine the impact of coal particle grinding size on carbon conversion

► The C-O2 reaction is diffusion-limited, while the C-CO2/C-H2O reactions are kinetics-limited under the tested conditions. ► Grinding finer than ∼134 μm speeds up carbon conversion in the GE gasifier and combustor section of the MHI gasifier. ► Fine grinding does not accelerate carbon conversion at the diffuser section of the MHI gasifier. ► Particles smaller than 36 μm undergo complete conversion within the oxygen-rich sections in both the MHI and GE gasifiers. ► The larger particles primarily convert through the C-CO2 and C-H2O reactions in the latter stages of the gasifiers.