Abstract: The present invention provides a high-efficient magnesium ion removal system for salt lake brine based on in situ alkali production using bipolar membrane electrochemical process, it is constructed with cathode, cathode cell, anode, anode cell, and anion exchange membranes, bipolar membranes, acid cells, alkali cells, mesh materials for precipitate aggregation, acid-washing cells.

Abstract: The present invention belongs to the field of alkaline polymer electrolyte membranes, and relates to a comb-shaped structure polybenzimidazole anion exchange membrane with high conductivity and preparation method thereof. In the invention, firstly, polybenzimidazole is grafted with the non-cationic side chains to the max grafting rate to synthesize the de-protonated comb-shaped polybenzimidazole material, avoiding the N—H in benzimidazole forms ionic binding with cationic functional groups, which will reduce the reactivity and mobility of cationic groups; then react de-protonated comb-shaped polybenzimidazole with quaternization reagent to attach the pendent side chain with cationic functional groups, making it easy to aggregate to form ion clusters and hydrophilic/hydrophobic microphase separation. The anion exchange membrane prepared in this invention has excellent conductivity, mechanical properties and alkaline stability.