Modeling of Power Generation and Acid Recovery in an Analogous Process of Reverse Electrodialysis

The feasibility of an analogous reverse electrodialysis (RED) process for power generation and acid recovery from acidic waste streams in the steel industry is investigated in this study. A comprehensive model was established to simulate the transport phenomena and power generation, which was validated through experimental data. The simulated operation time was 3 h, during which an acid recovery rate of 41.7% was achieved, and the maximum output power density reached 30.37 μW·cm^-2. The results demonstrated a strong dependence of output power density on the acid concentration, with a linear relationship within the tested range of 1.0-3.0 mol·L^-1 HCl. An optimal flow rate range was identified that maximized power output, with the best value of 90 mL∙min^-1. The differences in energy harvesting between the traditional acid diffusion dialysis process and our analogous RED process were demonstrated via simulation. The importance of system electroneutrality in driving ion migration and forming ionic currents was crucial for effective power generation. The analogous RED process is a promising solution for efficient acid recovery and power generation from industrial acid waste, offering a sustainable treatment approach.