INTERPRETATION OF THE MECHANISM DIFFUSION IN THE GAS-SOLID PROCESS OF THE DESSULFURIZATION REACTION

INTERPRETATION OF THE MECHANISM DIFFUSION IN THE GAS-SOLID PROCESS OF THE DESSULFURIZATION REACTION. The present paper aims to interpret the SO(2) diffusion mechanism process for two different limestones: a calcite and a dolomite. In previous study, the apparent activation energies for sulfation reaction were between 3.03 and 4.45 kJ mol(-1) for the calcite, and 11.24 kJ mol(-1) for the dolomite. Using nitrogen porosimetry it was possible to observe that the dolomite presents mesopores of 0.03 mu m, while the calcite presents mesopores of 0.01 mu m. The evaluation of limestones porous structure together with their kinetic parameters, allowed concluding that the diffusion mechanism follows Fick law and Knudsen law for dolomite and calcite, respectively.