Low temperature H2S dry-desulfurization with zinc oxide

A commercially available zinc oxide with a bimodal micro- and mesopore size distribution was investigated as a desulfurizing sorbent in a fixed-bed reactor at low temperatures from 60 to 400 °C. Fresh and sulfided materials were characterized by X-ray diffraction (XRD), BET specific surface area, pore volume, SEM/EDX, TGA/DSC and in situ X-ray diffraction (XRD). The sorbent’s sorption capacity at breakthrough increased with the sulfidation temperature reaching 87% of the theoretical value for desulfurization at 400 °C. A deactivation model that considers the activity of the solid reactant was used to fit the experimental data. Good agreement between the experimental breakthrough curves and the model predictions was obtained.