DOUBLE DECOMPOSITION METHOD OF NEUTRAL SALT

摘要

PURPOSE:To produce high-concn. acid and alkali at high current efficiency, by feeding a neutral salt aq. soln. to an intermediate salt chamber which is formed with a specified cation exchange membrane and an anion exchange membrane provided between an anode and a cathode and subjecting the neutral salt aq. soln. to electrodialysis. CONSTITUTION:A cation exchange membrane having an anion exchange layer on at least one surface, a bipolar membrane which has both the anion exchange layer and a cation exchange layer and has >=10N fixed ion concn. of the above- mentioned cation exchange layer and an anion exchange membrane having amino radical bonded with long-chain alkyl radical are arranged in order between an anode and a cathode. Electrodialysis is performed by using a three- chamber type electrodialysis tank having the above-mentioned constitution and feeding a neutral salt aq. soln. such as sodium chloride to an intermediate salt chamber between the cation exchange membrane and the anion exchange membrane. Thereby the above-mentioned neutral salt is subjected to double decomposition at high current efficiency and high-concn. acid and alkali are obtained.