Reaction kinetics of CuO/γ-$Al_2O_3$ - $SO_2$ and the kinetics of thermal decomposition of the sulfated sorbent in a thermogravimetric analyzer (TGA) have been studied. The effects of calcination temperature (450~800℃), sulfation temperature (250~550℃), CuO loading on $γ-$Al_2O_3$ (2~11 wt%), particle size (0.01~5mm), $SO_2$ concentration (2000~9000 ppm), alkali salt loading (NaCl; 0~10 wt%), and sorbent type (γ-$Al_2O_3$, silica-alumina) on sulfation reaction of the sorbent have been determined. In thermal regeneration of the sorbent, the effect of temperature (600~900℃) on the thermal decomposition of sulfated sorbent has been determined. Also, the effects of calcination temperature (500~700℃), CuO loading on $γ-$Al_2O_3$(2~8wt%), and sulfation time (0~150 min) on the physical properties (pore size distribution, surface area) of the sorbent have been determined.
The optimum calcination temperature for the sulfation reaction of the sorbent is found to be 600℃. Sulfation reaction rate of the sorbent impregnated with CuO 6~11 wt% at the reaction temperature above 500℃ increases lineally with reaction time in the S/Cu mole ratio between 1.5 and 7. The optimum CuO loading at 500℃ is found to be 8 wt % based on the sulfur capture capacity and S/Cu mole ratio in the sorbent. The saturated sulfur capture capacities of the sorbents increase with decreasing CuO loading and increasing reaction temperature. Activation energy for the reaction of CuO/$γ$-$Al_2O_3$-$SO_2$ is 12.7 kJ/gmol. The reaction order of CuO/γ-$Al_2O_3$-$SO_2$ with respect to $SO_2$ concentration of 1000 - 5000 ppm is found to be 1st order. As an additive, NaCl was impregnated on CuO (8 wt%)/γ-$Al_2O_3$ sorbent which enhances sulfation the reaction rate and the optimum NaCl loading is found to be 5 wt.% whereas, the rate of increase in sulfation reaction decreases with 10 wt%-NaCl loading. With the additive of NaCl, ($1.5>S/Cu$ mole ratio) sulfation reaction rate of the sorbent (CuO 8 wt%) impregnated with 5 wt% - NaCl at reaction temperature above 400℃ increases lineally with reaction time in the S/Cu mole ratio of 1.5~7.0 and the saturated sulfur capture capacity of the sorbent is found to be a S/Cu mole ratio of 10. Pore volumes of the sorbent decrease with increasing reaction time, calcination temperature. Pore size distribution of the sorbent is shifted to larger pore size after the thermal regeneration at 800℃. Sulfation reaction rate and the sulfur capture capacity of the regenerated sorbent decrease with increasing the number of reaction cycle in sulfation and regeneration.
