Integrating Diffusion Dialysis with Membrane Electrolysis for Recovering Sodium Hydroxide from Alkaline Sodium Metavanadate Solution

Here, an energy-saving and efficient method is proposed for the clean and sustainable production of typical metal oxide (vanadium pentoxide as a case) by integrating diffusion dialysis with membrane electrolysis via cation-exchange membranes. This integrated process can achieve alkali recycle with less energy consumption. In addition, the gases—H2 and O2—produced in the membrane electrolysis process can be used as byproducts. Results indicate that the total alkali recovery ratio and the vanadium rejection ratio can be as high as ∼100% and ∼92.56%, respectively. Moreover, preliminary economic evaluation indicates that the running cost can be significantly decreased from $24.52/(m3 feed) (traditional method) to $–24.18/(m3 feed) (proposed method).