PURPOSE: To separate and recover sulfuric acid favourably by the conversion of sulfuric acid to CaSO4 and CaSO3 and to regenerate activated carbon by a method wherein SOx adsorbed on activated carbon is oxidized to convert SOx to sulfuric acid, powdery calcium compound is added and the mixture is treated at an elevated temperature.
CONSTITUTION: Exhaust gas 1 is introduced into an adsorption apparatus 2 filled with activated carbon. SOx is adsorbed by the activated carbon and simultaneously SOx is coverted to solfuric acid by the presence of adsorbed water and O2. The activated carbon containing sulfuric acid is supplied to a vibration sieve 4 to remove deposited dust 5 and then is supplied to a moving bed type activated carbon regeneration furnace 6 where the activated carbon is uniformly mixed with calcium compound such as powdery CaCO3 heated at an elevated temperature in part 11. Sulfuric acid on the surface of the activated carbon is reacted with CaCO3, Ca(OH)2 or CaO to convert sulfuric acid to CaSO4 or CaSO3 which is then discharged together with the activated carbon from the lower part of the furnace 6. The mixture is treated with a vibration sieve 8. A mixture 12 of CaSO4 and CaSO3 is separated and recovered. Activated carbon is returned to the apparatus 2 to reuse it.
WATANABE TETSUO
NISHIZAKI SHINJI
