A gas‐solid reaction model — Variable temperature, pressure and structural parameters

Diffusion and reactions in a porous pellet are treated as transient, nonisothermal, nonisobaric processes. Continuity and energy balance equations are solved simultaneously for temperature and concentration profiles in the pellet. Conductive, convective as well as radiative heat transfer are included. The ‘dusty gas’ flux model is used to describe the transport of diffusing gases. Viscous, bulk and concentration gradient terms have been included. Structural changes with reaction are accounted by considering the effect of changing grain radius on porosity and pore diameter. The model predictions match conversion trends for carbon gasification over a temperature range of 800 to 1100°C investigated experimentally.