Gasification: Part I. Isothermal, kinetic control model for a solid with a pore size distribution

A model describing the development of specific surface area, volume, porosity, and mean pore radius of a porous solid with extent of gasification is developed based on consideration of pore size growth, initiation of new pores, and coalescence of adjacent pores. Use of population balances and formulation of the properties as moments of the pore size distribution leads to a mathematically simple, closed set of equations for kinetically controlled gasification. The model successfully predicts maximums in specific surface area and number of pores observed by Kawahata and Walker (1962) in the activation of devolatilized anthracite by CO2 in a fluidized bed.