| 摘要 |
PURPOSE: To provide a fluorocarbon decomposing system capable of treating fluorocarbon without lowering the decomposition sctivity of fluorocarbon when a large amt. of highly conc. fluorocarbon is treated by providing a first catalyst bed decomposing fluorocarbon and absorbing at least a part of hydrogen fluoride and/or hydrogen chloride generaled accordingly to the decomposition fluorocarbon in a front stage while providing a second catalyst bed decomposing residual fluorocarbon in a rear stage. CONSTITUTION: Fluorocarbon-containing exhaust gas 1 is mixed with oxygen 2 to be introduced into a first catalyst bed 3 packed with a calcia catalyst at reaction temp. of 400 deg.C. The hydrolytic decomposition reaction of fluorocarbon is advanced on the catalyst to form CO2 , HF, HCl and water. Next, the exhaust gas is introduced into a salt recovery process 4 packed with an aq. NaOH soln. to form Na and sodium chloride A. Further, the exhaust gas is introduced into a CaF2 recovery process 5 packed with Ca(OH)2 to recover CaF2 and sodium chloride, and the formed gas becomes a mixture of unreacted gas and air. This gas is mixed with oxygen 2 to be introduced into a second catalyst bed 6 pocked with a TiO2 -W catalyst at reaction temp. of 400 deg.C and the hydrolytic decomposition reaction of hydrocarbon advanced on the catalyst to decompose fluorocarbon. |
