Correlations of Ion Composition and Power Efficiency in a Reverse Electrodialysis Heat Engine

International Journal of Molecular Sciences

Yang Wang¹  Maolin Sha²  Fabao Luo²  Yanxin Wei² 

[1] CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China;School of Chemistry and Chemical Engineering, Hefei Normal University, Hefei 230061, China;

关键词: salinity gradient power;    reverse electrodialysis;    concentration difference;    electrolyte composition;   

DOI  :  10.3390/ijms20235860

来源: DOAJ

【 摘 要 】

The main objective of this study is to explore the influence of ion composition on the trans-membrane potential across the ion exchange membrane (IEM), and thus offers a reference for the deep insight of “reverse electrodialysis heat engine” running in the composite systems. In comparison to the natural system (river water | seawater), the performance of the reverse electrodialysis (RED) stack was examined using NaHCO₃, Na₂CO₃, and NH₄Cl as the supporting electrolyte in the corresponding compartment. The effect of flow rates and the concentration ratio in the high salt concentration compartment (HCC)/low salt concentration compartment (LCC) on energy generation was investigated in terms of the open-circuit voltage (OCV) and power density per membrane area. It was found that the new system (0.49 M NaCl + 0.01 M NaHCO₃|0.01 M NaHCO₃) output a relatively stable power density (0.174 W·m⁻²), with the open-circuit voltage 2.95 V under the low flow rate of 0.22 cm/s. Meanwhile, the simulated natural system (0.5 M NaCl|0.01 M NaCl) output the power density 0.168 W·m⁻², with the open-circuit voltage 2.86 V under the low flow rate of 0.22 cm/s. The findings in this work further confirm the excellent potential of RED for the recovery of salinity gradient energy (SGP) that is reserved in artificially-induced systems (wastewaters).

【 授权许可】

Unknown