METHOD FOR TREATING FLUE GAS

摘要

PROBLEM TO BE SOLVED: To facilitate the treatment of carbon dioxide separated by solidification from flue gas at a low temperature by converting the recovered solids into liquid CO2 by heating and pressurizing, and to facilitate energy circulation without polluting global environment. SOLUTION: Flue gas discharged from a boiler 1 is cooled by a heat exchanger, and water is separated from the flue gas in a gas-liquid separator 5 and then most of the remaining water is solidified and separated as ice in an ice crystallizer 13. The flue gas is cooled in a carbon dioxide gas solidification apparatus 16, the contained carbon dioxide gas is solidified as dry ice and then the dry ice is separated from the flue gas in a solid-gas separator 18. Furthermore, the dry ice is converted to liquid carbon dioxide by pressurizing in a carbon dioxide liquefying apparatus 21 and is stored in a storage 23. The heat of the flue gas which has separated the dry ice is recovered among the carbon dioxide gas solidification apparatus 16, the ice crystallizer 13 and a low temperature heat exchanger 8 via a plurality of heat exchangers 31-33.