METHOD AND APPARATUS FOR DECOMPOSING CARBON DIOXIDE

PURPOSE:To reduce the discharge of CO2 to the atmosphere by continuously and stably decomposing CO2 in exhaust gas using the coke oven gas and recovered iron oxides generated in a steel making process. CONSTITUTION:Recovered iron oxides 1 are supplied to a reaction tank 4 and coke oven gas 6 heated so as to set the reaction temp. in the reaction tank 4 to 350-600 deg.C is blown in the reaction tank 4 to modify recovered iron oxides 1 to form reduced iron 5. This reduced iron 5 is received in the CO2 decomposing reaction tank 19 communicating with the reaction tank 4 and CO2-rich gas 25 containing at least 30% or more of CO2 on a volume % basis is heated so that the CO2 decomposition reaction temp. in the reaction tank 19 becomes 350-600 deg.C to be blown in the reaction tank 19. The CO2-rich gas is allowed to react with the reduced iron 5 to decompose CO2. As a result, the discharge of CO2 to the atmosphere can be reduced and the carbon bonded iron oxide 20 obtained by this method is appropriately fed and can be utilized as an iron making auxiliary raw material of an iron or carbon source.