Sulfation behavior of CuO/γ-Al2O3 sorbent for the removal of SO2 from flue gas

CuO/γ-Al₂O₃ has been considered as a promising and recycling sorbent to remove sulfur dioxide from flue gas. In this study, a series of CuO/γ-Al₂O₃ sorbents with different CuO loadings were prepared by impregnation. The monolayer coverage of CuO supported on γ-Al₂O₃ determined by X-ray quantitative analysis was 0.275 g CuO/g (γ-Al₂O₃). Below the monolayer coverage, CuO was found highly dispersed on γ-Al₂O₃. Thermogravimetric technique was used to study sulfation kinetics and sulfation recycling. It was found that the Langmuir kinetic adsorption model described well the experimental data at the rapid sulfation region of the CuO/γ-Al₂O₃ sorbent. The adsorption activation energy was 19.98 kJ/mol and the pre-exponential factor was 9.97×10⁻⁵ s⁻¹ · Pa⁻¹. The CuO/γ-Al₂O₃ sorbent has shown good performance on regeneration, but long sulfation time might cause the deactivation of the CuO/γ-Al₂O₃ sorbent. It was also seen that the sulfated γ-Al₂O₃ support could not be reduced at 400°C.