| 摘要 |
PURPOSE:To obtain CO2 gas of high concentration, by decomposing limestone, etc. with the heat of combustion generated by burning a fuel in a reacting furnace, keeping the CO2 concentration in the produced gas at a specific value, and recovering the CO2 gas. CONSTITUTION:A powdery limestone or dolomite is fed from a feed port 2 into a reaction furnace 1, and a gas produced in the reaction furnace 1 is fed partially from the bottom feed port 12 to form a fluidized bed 3. Furthermore, a fuel and O2 with a nitrogen content <=20% are fed from feed ports 4 and 5 respectively into the furnace 1 to burn the fuel, and the limestone, etc. is decomposed with the heat of combustion into a calcined material and CO2 gas. The calcined material is discharged from a discharge port 6. On the other hand, the produced gas is taken out of a discharge port 13, passed through a dust removing apparatus 7 and a cooler 8 to remove dust and moisture. Thus, CO2 gas having a CO2 concentration >=75vol% is obtained. The resultant CO2 gas is partially passed through a booster 10 and preheater 11 and circulated through the feed port 12 and furnace 1. Most of the remaining CO2 gas is passed through a low temperature separating apparatus 9 to further increase the CO2 concentration and give the CO2 gas of given purity. |
