High-temperature, short-time sulfation of calcium-based sorbents. 1; Theoretical sulfation model

This paper reports on a mathematical model for the sulfation of CaO developed around the overlapping grain concept. The potential influence of high mass-transfer rates from simultaneous calcination of CaCO{sub 3} or Ca(OH){sub 2} is incorporated in the mass-transfer coefficient for SO{sub 2} diffusion to the particle. A solution scheme for the nonlinear differential equation governing pore diffusion with changing particle structure is developed. The influence of grain overlap on product-layer diffusion is quantified. The model predictions show good agreement with published, fundamental differential reactor data which include the influences of surface area, temperature, and SO{sub 2} partial pressure.