An Innovative Beneficial Reclamation of Flue Gas Desulfurization Brine Using Bipolar Membrane Electrodialysis Technique

摘要

Flue gas desulfurization (FGD) brine containing high salinity poses a significant challenge to theimplementation of environmental policy in china. In this work, an innovative alternative approach ofbipolar membrane electrodialysis (BMED) technique has been proposed to effectively reuse this brineby the acid and base production on the premise of zero emission requirements. The experimentalresults demonstrate that the high acid and base concentrations in excess of 1.0 mol/L can be obtainedwith the satisfactory desalination. Higher initial salt concentration shows nearly no significant changeon current efficiency, acid/base concentration and acid volume. Nevertheless, appropriateconcentration for ×2 of FGD brine is necessary and beneficial for acid/base production by the decreaseof energy consumption from 2.34 to 2.14 Kwh/kgNaOH. Additionally, the ions migration between Cland SO42- indicates high purity HCl with little H2SO4 contamination can be obtained if the initial saltconcentration of FGD brine is improved in the earlier acid production. In conclusion, BMED presentsa high potential for FGD brine treatment in view of environmentally friendly as well as attractiveeconomic benefit.