摘要 |
PROBLEM TO BE SOLVED: To reduce a load on a reheater by enabling a decomposition treatment of an organic compound of dioxins or the like in an exhaust gas in a low temperature atmosphere by combining an apparatus which easily discharges a catalyst of which decomposing performance is degraded outside a packed column with an apparatus which regenerates the degraded catalyst. SOLUTION: Since the temperature of an exhaust gas at an inlet of a catalyst packed column 2 is about 170 deg.C, ammonium sulfate and ammonium hydrogensulfate are separated on the surface of the catalyst, and decomposing performance of an organic compound of dioxins or the like is lowered in a short time. Since the decomposing performance of the catalyst near the inlet of the exhaust gas of the catalyst packed column 2 is most lowered at that time, the catalyst in this part is periodically discharged outside the catalyst packed column. The discharged catalyst is sent to a catalyst regenerator 3, ammonia-gas-containing exhaust gas heated at about 350 deg.C is flowed to the catalyst regenerator 3 by a purging line 4, and the exhaust gas and the catalyst are brought into gas-solid contact. Thereby, ammonium sulfate and ammonium hydrogensulfate which are separated on the surface of the catalyst can be desorbed, and the catalyst can be regenerated. |