公开(公告)号：US20210069645A1

公开(公告)日：2021-03-11

申请号：US16978985

申请日：2019-03-12

Applicant: BL TECHNOLOGIES, INC.

Inventor： Chengqian ZHANG ,  Wei LU ,  Jiyang XIA ,  Yongchang ZHENG ,  Bruce BATCHELDER ,  John H. BARBER

IPC: B01D61/44 ,  B01D61/46 ,  B01D69/02 ,  C02F1/469

Abstract: A bipolar electrodialysis (BPED) cell is able to bipolar convert salt solutions into acid and base solutions. However, protons migrate through the anion exchange membranes and tend to neutralize the base solution. In a bipolar electrodialysis system described herein, multiple BPED cells are arranged to provide a multi-stage treatment system. Up to half, or up to one third, of the stages have cells with acid block anion membranes. The one or more stages with acid block anion membranes are located at the acid product output end of the system, where the acid concentration in the system is the highest. Replacing the traditional anion membranes in some of the stages with acid block anion membranes allows higher concentration products to be produced with moderate increase in energy consumption.