Regeneration of mixed solvent by electrodialysis: selective removal of chloride and sulfate

The applicability of electrodialysis for the selective removal of sulfate and chloride ions from a mixed solvent solution of sodium carbonate is investigated. The mixed solvent consists of 70 wt.% ethylene glycol and 30 wt.% water. Six different ion exchange membranes, the homogeneous membranes Neosepta CM-2, AM-3, AMX and ACM as well as the heterogeneous FuMA Tech CM-A and AM-A, are tested for their chemical and physical resistance to the mixed solvent carbonate solution, their ethylene glycol retention, their electrical resistance in the mixed solvent and their selectivity for sulfate and chloride over carbonate transport.