| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for treating waste gas by which a high SOx removal efficiency can be maintained independently of the burning conditions of a boiler even if unburned carbon in waste gas enters into or sticks to an SOx remover. SOLUTION: In the method for treating waste gas in which NH3 is injected into waste gas to remove NOx in the waste gas and this waste gas is fed to an SOx removal equipment using a hydrated and cured body containing lime, gypsum and coal ash as an SOx remover to remove SOx in the waste gas, the concentration of SO2 in the waste gas at the inlet of the SOx removal equipment and that at the outlet are measured and the amount of NH3 injected into the waste gas is controlled so that SOx removal efficiency calculated from the measured values is made constant, or the concentrations of SO2 and NO in the waste gas at the inlet of the SOx removal equipment are measured and the amount of NH3 injected into an NOx removal equipment is controlled so that the concentration ratio of NO to SO2 is made >=0.2. |
