| 摘要 |
PROBLEM TO BE SOLVED: To prevent the increase in the SO2 -oxidation ratio of a denitration catalyst caused by vanadium contained in exhaust gas by keeping the catalyst packing part of a dry exhaust gas denitrizer at the dew point of sulfuric acid or above even when the denitrizer is stopped when fuel of a relatively high vanadium content is used. SOLUTION: Nitrogen oxides in exhaust gas discharged from combustion facilities which use fuel containing 0.5% or more of sulfur components are decomposed and removed by a dry exhaust gas denitrizer 1. In this process, the catalyst packing part 3 of the denitrizer 1 is kept at the dew point of sulfuric acid or above by an electric heater 7, etc., even when the denitrizer 1 is stopped. In this way, since the generation of liquid components and the permeation of vanadium components into the catalyst can be prevented, the increase in the SO2 -oxidation ratio of the catalyst can be prevented. |
