Mo and Co doped V_2O_5/AC catalyst-sorbents for flue gas SO_2 removal and elemental sulfur production

摘要

Flue gas SO_2 removal at 200 ℃ over Mo and Co doped V2O5/AC catalyst-sorbents and regeneration of the used catalyst-sorbents in H_2 at 380 ℃ in the same reactor are studied in this paper. Compared with V_2O_5/AC, the catalyst-sorbents containing Co show higher SO_2 uptake while the one containing Mo shows a slightly lower SO_2 uptake. Elemental sulfur is produced during H_2-regeneration of the used catalyst-sorbents when effluent gas of the regeneration is recycled back to the reactor. H_2-regeneration of the used V_2O_5/AC produces little elemental sulfur, but the Mo and Co doped ones show high elemental sulfur yields with an elemental sulfur selectivity of 50% for a catalyst-sorbent containing 2% V_2O_5, 0.5% MoO_3 and 0.5% CoO, V2Mo0.5 Co0.5/AC. Molybdenum and cobalt sulfides are likely formed in the regeneration, which catalyze the elemental sulfur formation but reduce the SO_2 uptake of the catalyst-sorbents in the subsequent SO_2 removal stage.