EFFECT OF NONUNIFORM SURFACE REACTIVITY ON THE EVOLUTION OF PORE STRUCTURE AND SURFACE-AREA DURING CARBON GASIFICATION

There is much experimental evidence that the gasification of carbon surfaces is often nonhomogeneous on a fine scale. Gasification of impure carbons, for example, often occurs in the immediate vicinity of catalytically active particles of inorganic matter, proceeding by the formation either of irregular pits or of channels of definite size and orientation. In the present paper, a model is presented which predicts the effect of nonuniform gasification on the evolution of surface area and pore size distribution for low-temperature porous carbons. Nonuniformity of surface reactivity can dramatically reduce the extent of surface area development during gasification or activation. Results of the model are used to explain several sets of previously published measurements of surface area evolution as a function of carbon conversion.