Influence of solution concentration and salt types on the performance of reverse electrodialysis cells

The influence of salt concentrations on the performance of reverse electrodialysis (RED) stacks has rarely been investigated using thermolytic salts such as NH4HCO3, that can be regenerated using waste heat and can be set at any desired concentration below saturation limits. Here, power densities produced by a RED stack were first investigated using different NaCl concentrations, and then tested using NH4HCO3. The power produced by the RED stack increased with NaCl concentrations from 0.6M to 3.6M in the HC (high concentration) solution, but it did not increase at higher salt concentrations due to limited ion exchange membrane capacity. NaCl concentrations larger than 0.14M in the LC (low concentration) solution decreased power primarily as a result of lower salinity ratios (