Dry SO2 Removal Process Using Calcium/Siliceous-Based Sorbents: Deactivation Kinetics Based on Breakthrough Curves

The removal of sulfur dioxide (SO2) from simulated flue gas was investigated in a laboratory‐scale stainless steel fixed‐bed reactor using sorbents prepared from various siliceous materials, i.e., coal fly ash (CFA), oil palm ash (OPA) and rice husk ash (RHA) mixed with lime (CaO) by means of the water hydration method. Experiments were carried out with a flue gas flow rate of 150 mL/min, reaction temperature of 100 °C, and SO2 concentration of 1000 ppm. It was found that sorbents prepared from RHA have high BET surface areas and high SO2 sorption capacities, based on breakthrough curve analysis. In addition, the SO2 breakthrough curves were also described in terms of a simple first‐order deactivation model containing only two rate constants, one of which, ks, describes the surface reaction rate constant while the other, kd, describes the deactivation rate constant. The values of ks and kd obtained from the deactivation kinetics model were in good agreement with the experimental breakthrough curves and were also compared with those available in the literature. The removal of sulfur dioxide from simulated flue gas was investigated in a laboratory‐scale stainless steel fixed‐bed reactor using sorbents prepared from various siliceous materials. Analysis of this sorbent deactivation is one of the important steps in the design and evaluation of fixed‐bed reactor performance under dry‐type desulfurization processes.