Circulation of Waste Proton Exchange Membrane from Vanadium Flow Battery

Abstract

This study aims to provide a sufficiency and simple method to recycle vanadium resource and recover membrane from waste proton exchange membrane of vanadium flow battery This study is divided into two parts which is recovery vanadium by ion exchange and recast of proton exchange membrane In the first part the waste membrane was dissolved in 50% ethanol solution to obtain membrane dispersion which concentration of vanadium was 74 mg/L In the ion exchange batch experiment the adsorptive behavior of the cation exchange resin Dowex G26 was correspond to Langmuir model and the maximum adsorb capacity were 94 34 The adsorption and elution column experiment was carried out by Dowex G26 resin The optimal parameter of adsorption part was flow rate 1ml/min BV=10ml and total 140BV and the saturated adsorption capacity reach 81 855 mg/g In elution part 1 mol/L HCl total 5BV was used to elute vanadium from resin and the concentration of enrichment solution was 1596 72 ppm which elution efficiency was 97 5% The vanadium was precipitated by adjusting pH value to 5 and adding NH4Cl to obtain the solid ammonium metavanadate The ammonium metavanadate was calcined in 450oC and 12 hours to get vanadium(V) oxide In the second part the dispersion was recast to obtain recycled membrane The recycle membrane has average thickness 209 2μm moisture 25 98% ion exchange capacity 0 565 meq/g and ion conductivity 3 62×10-3 S/cm

Date of Award	2021
Original language	English
Supervisor	Wei-sheng Chen (Supervisor)