离子交换膜隔膜电解法间接精制4B酸

Indirect purifying 4B acid by ion exchange membrane electrolysis process

采用含有离子交换膜的三区电解槽,以H2SO4和(NH4)2SO4为电解液,阴极区和阳极区分别产生相应的碱和酸.阴极碱性液溶解4B酸粗品,活性炭吸附除去从粗品中溶出的对甲苯胺等杂质,中间区的酸性液使4B酸精品析出.阴极区和中间区的电解液为60g/L(NH4)2SO4,阳极区的电解液为45g/LH2SO4.电流效率77.4%,收率≥97%,精制品符合出口标准.

The ion exchange membrane electrolysis cell with three compartments has been used to purify 4B acid.The basic liquid from cathode compartment solves crude product of 4B acid.The p-methylaniline and other impurity in the crude product are adsorbed by active carbon and the purified 4B acid is precipitated out by acidic solution from middle compartment.The electrolyte in anode zone and middle compartment is aqueous solution of 60 g/L (NH_4)_2SO_4.The electrolyte in anode zone is 45 g/L H_2SO_4.The current efficiency is 77.4% and yield≥97%.The purified product comes up to the export standard.