The kinetic rate of SO₂ sorption by CaO

Abstract

The intrinsic rate constant for the rate of reaction of SO, with porous CaO in an excess of 0, to form CaSO, has been determined from SO, sorption data on a wide range of particle diameters (1 pm-1 mm), SO, partial pressures (60 Pa to 5 kPa), and temperatures (973-1,478 K). An intrinsic SO, reaction order of unity has been validated through current fixed-bed experiments in the 60 to 300 Pa SO, partial pressure range, while fluidized-bed data were used to validate the reaction order from 500 Pa to 5 kPa SO, partial pressure. The absolute value of the rate constant and the activation energy was derived from data on small (1 pm) particles, which approach the limit of kinetic control. While analysis of this data base does minimize the role of intraparticle diffusion through the porous sorbent particle, the filling of the small pores by the product deposits and the associated loss of internal surface area is critical to the data reduction. It is believed that the intrinsic rate constant is known to the accuracy to which the reactivity and the BET surface area may be measured.

Surface area evolution of calcium hydroxide during calcination and sintering

“…The dependence of apparent sorbent reactivity on calcine specific surface area has been addressed by others (Simons and Garman, 1986;Simons et al, 1987;. However, much of the previous work has used extremely simplified interpretations of the phenomena involved, namely the simultaneous occurrence of calcination and sintering.…”

Modelling of the kinetics of sulphation of CaO particles under CaL reactor conditions

“…Simons et al [51] assumed that the distribution is like a complex tree where the pore size decreases the further inside the particle the pore is. One of the most widely used pore models is the model developed by Bhatia and Perlmutter [52,53]: the random pore model (RPM), which assumes that the particle is traversed by random size cylindrical pores with intersecting and overlapping surfaces as reaction proceeds.…”

Sulfur Removal in Bio-Briquette Combustion Using Seashell Waste Adsorbent at Low Temperature

“…The mechanisms of desulfurization using calcium-based adsorbent have been established and applied elsewhere [37][38][39][40]. In this study, the desulfurization mechanism used a previously proposed model.…”