摘要
How to enhance the SO 2 tolerance of transition metal oxide-supported activated carbon is one of the hottest issues in the field of mercury capture from flue gas. Addition of a foreign metal ion to prepare bimetallic adsorbent is a common method of improving the SO 2 tolerance of adsorbent. However, this approach suffers from high cost and a complex preparation process. In this study, CeO 2 - and Co 3 O 4 -supported activated carbon ( m %CeO 2 /AC and m %Co 3 O 4 /AC), with various loading values of active center, were prepared by an incipient wetness impregnation method, and their SO 2 tolerances were compared. The mercury removal performance and SO 2 tolerance of both CeO 2 /AC and Co 3 O 4 /AC could be remarkably improved through increasing the loading amount of the active center. Co 3 O 4 /AC exhibited high affinity with SO 2 , and the chemisorbed oxygen in Co 3 O 4 would be largely consumed, when SO 2 was present in the flue gas, resulting in a significant decrease of mercury removal efficiency. The mercury removal efficiencies of 20%CeO 2 /AC, 40%CeO 2 /AC and 60%CeO 2 /AC were 86.1%, 93.7% and 93.7%, respectively, during removal of mercury from flue gas at 150 °C in the presence of SO 2 . 20%CeO 2 /AC was the optimal adsorbent for mercury capture from flue gas, owing to its excellent mercury removal efficiency, strong SO 2 tolerance and relatively lower cost. The mercury species formed over spent 20%CeO 2 /AC were HgO and HgSO 4 . The HgO was generated through the reaction of mercury and chemisorbed oxygen, while the formation of HgSO 4 was due to the reaction between mercury, SO 2 and chemisorbed oxygen. The regeneration investigation indicated that the activity of spent 20%CeO 2 /AC could be almost fully recovered through a temperature-programmed decomposition and desorption process. The present study showed that the SO 2 tolerance of CeO 2 /AC could be easily improved through regulation of the loading amount of the active center.
危险品化学品经营许可证（带存储）