Hydrogen and electricity cogeneration driven by the salinity gradient from actual brine and river water using reverse electrodialysis

• Published in: Applied energy Vol. 367; p. 123320
• Main Authors: Wu, Xi, Chen, Zhiwei, Han, Zhaozhe, Wei, Yonggang, Xu, Shiming, Zhu, Xiaojing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Actual brine; Energy conversion; Hydrogen production; Reverse electrodialysis; Salinity gradient energy; Salinity gradient energy; Actual brine; Hydrogen production; Energy conversion; Reverse electrodialysis
• ISSN: 0306-2619
• DOI: 10.1016/j.apenergy.2024.123320

Reverse electrodialysis (RED) is a promising method for harvesting the salinity gradient energy (SGE) between the brine and river water. Many investigations are carried out by using the artificially brine and fresh water, bringing difficulties in reflecting the practical RED performance under the complex influences of feed solutions. This work explores the performance of the RED system for hydrogen and electricity co-generation that is driven by salinity gradient between the actual concentrated brine and natural river water, and compared with the simulative brines and river waters under six testing schemes. The results show both the working current and solutions influence the system performances, including the output voltage, power density, hydrogen production, and energy conversion efficiency. Besides, the effects of salinity gradient of feed solutions are greater than that of the presence of trace multivalent ions and anionic radical in brine. The effective monovalent ion ionic strength is vital. The experimental maximum hydrogen production and power density are 82.12 mL·h−1 and 0.124 W·m−2 respectively at the current is 0.2 A, and the total power reached 0.32 W with the energy conversion efficiency of 25%. The research offers recommendations for harnessing SGE from actual brines and freshwater to produce hydrogen. •An innovative process of energy recovery from the actual brines and freshwater was presented.•A reverse electrodialysis stack was built to produce H2 driven by actual brine and river water.•Feasibility is analyzed based on the comparation testes by 3 brines and 3 fresh waters schemes.•Maintaining a suitable working current heightens H2 production and total power output.•Power density is 0.149 W·m−2 and H2 production is 82.12 ml·h−1, at the current is 0.2 A.