TREATMENT OF STACK GAS OF FLUIDIZED-BED BOILER

摘要

PROBLEM TO BE SOLVED: To provide a method capable of realizing the desulfurization of a stack gas generated in a fluidized-bed boiler with simpler equipment constitution. SOLUTION: This method for treating a stack gas is provided with a desulfurization process in a fluidized-bed boiler in which sulfur dioxide in the stack gas generated by fluidizing a desulfurizing agent and a fuel grain in the fluidized-bed boiler 1 are absorbed by the desulfurizing agent, a conversion process in which the sulfur dioxide remaining in the stack gas A2 discharged from the boiler 1 and passed through a gas turbine 3 is converted to sulfur trioxide by a converter 10 packed with a conversion catalyst, a deposition process in which the sulfur trioxide in the stack gas A3 generated in the conversion process and contg. the sulfur trioxide is reacted with injected ammonia B to deposit ammonium sulfate and a dusk removing process in which a solid component in the stack gas A4 contg. the deposited ammonium sulfate generated in the deposition process is removed by a dust removing means 8.