HIGH-TEMPERATURE, SHORT-TIME SULFATION OF CALCIUM-BASED SORBENTS .1. THEORETICAL SULFATION MODEL

A mathematical model for the sulfation of CaO is developed around the overlapping grain concept. The potential influence of high mass-transfer rates from simultaneous calcination of CaC03or Ca(OH)2is incorporated in the mass-transfer coefficient for SO2diffusion 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 SO2partial pressure. © 1990, American Chemical Society. All rights reserved.