HOT GAS DESULFURIZATION WITH VANADIUM-PROMOTED ZINC FERRITE SORBENTS

The performance of zinc ferrite promoted with V2O5 was investigated as a hot gas desulfurization sorbent. The sorbents were prepared by the incipient impregnation technique, and the vanadium loading and the calcination temperature were varied. The sorbents were tested in a packed-bed microreactor set-up for five sulfidation-regeneration cycles to investigate their breakthrough behaviour. Sulfidation was performed at 873-973 K with H2S-H2-H2O-N2 mixtures, while regeneration was carried out at 923-973 K with O2-N2 mixtures. The fresh, sulfided, and regenerated sorbents were characterized by atomic absorption spectroscopy, X-ray diffraction, surface areas and porosity measurements. The results of the investigation indicated that the sorbents exhibited a more stable cyclic performance with higher vanadium loading, all vanadium-promoted sorbents reduced the H2S content of the gas to levels below the equilibrium level for zinc oxide, some H2S was chemisorbed by vanadium, and two-step calcination imparted structural stability to the sorbents.