Modeling of the reactions of a calcium-based sorbent with sulfur dioxide

Abstract

A mathematical model of calcium sorbent reactions for the simulation of sulfur dioxide reduction from pulverized coal combustion flue gasses was developed, implemented within a numerical code and validated against available measurements under controlled conditions. The model attempts to resemble closely the reactions of calcination, sintering and sulfation occurring during the motion of the sorbent particles in the furnace. The sulfation was based on the partially sintered spheres model (PSSM), coupled with simulated particle calcination and sintering. The complex geometry of the particle was taken into account, with the assumption that it consists of spherical grains in contact with each other. Numerical simulations of drop down tube reactors were performed for both CaCO3 and Ca(OH)2 sorbent particles and results were compared with experimental data available from the literature. The model of the sorbent reactions will be further used for simulations of desulfurization reactions in turbulent gas-particle flow under coal combustion conditions.