Abstract: The activated carbon (AC)-supported V2O5 catalyst-sorbent, V2O5/AC, was found to be very effective for the simultaneous removal of SO2 and NO from flue gas at 200 ℃. The catalyst-sorbent, however, may suffer from high carbon loss during periodical regeneration required by the SO2 removal process. The SO2-adsorbed V2O5/AC catalyst-sorbent could be regenerated in the presence of NH3 at low temperature (300 ℃), and the carbon burn-off is much less than that in an inert atmosphere. In this study, the behaviors and mechanism of carbon burn-off during the regeneration of V2O5/AC in 5%NH3-95%Ar were studied using temperature-programmed desorption, elemental analysis,X-rayphotoelectron spectroscopy, and Fourier transform infrared spectroscopy. The carbon consumption amount for the regeneration carried out in 5%NH3-95%Ar is much lower than that in Ar atmosphere. The presence of NH3 inhibits the carbon burn-off by reacting with the surface oxygen-containing groups in V2O5/AC,-COOH,-OH,and V2O5 etc, to produce H2O and nitrogen-containing groups such as-CONH2,C-N,andC≡N.

Key words: ammonia, vanadium pentoxide, activated carbon, oxygen-containing group, carbon burn-off, catalyst regeneration, sulfur dioxide, nitric oxide