PURPOSE: To efficiently recover an acid and alkali from an absorbing soln. having absorbed SO2 in low energy cost and react the acid with a Ca compd. to reutilize the same as gypsum by providing an electrodialytic water splitter system wherein a bipolar membrane is provided in a process desulfurizing exhaust gas containing SO2.
CONSTITUTION: Exhaust gas containing SO2 is brought into contact with a basic aq. soln. form an aq. soln. of a salt having absorbed GO2 from the gas containing SO2 to perform desulfurization. When an acid or alkali or both of them are recovered from the aq. soln. of the salt formed at the time of absorption, a process recovering the acid or alkali or both of them by an electrodialytic water splitter system 14 consisting of a bipolar membrane and an anion exchange membrane or a cation exchange membrane or a combination of both ion exchange membranes and a process reacting the acid recovered by the electrodialytic water splitter system 14 with a Ca compd. to form gypsum are executed.
UMEMURA KAZUO
MIYAKE HARUHISA
