Jiang Yuxin, Jin Linfeng, Wei Dun, Alhassan Sikpaam Issaka, Wang Haiying, Chai Liyuan
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Chemical and Environmental Engineering Department, College of Engineering, University of Arizona, Tucson, AZ 85721, USA.
Int J Environ Res Public Health. 2022 Aug 25;19(17):10599. doi: 10.3390/ijerph191710599.
Capacitive deionization (CDI) is an emerging eco-friendly desalination technology with mild operation conditions. However, the energy consumption of CDI has not yet been comprehensively summarized, which is closely related to the economic cost. Hence, this study aims to review the energy consumption performances and mechanisms in the literature of CDI, and to reveal a future direction for optimizing the consumed energy. The energy consumption of CDI could be influenced by a variety of internal and external factors. Ion-exchange membrane incorporation, flow-by configuration, constant current charging mode, lower electric field intensity and flowrate, electrode material with a semi-selective surface or high wettability, and redox electrolyte are the preferred elements for low energy consumption. In addition, the consumed energy in CDI could be reduced to be even lower by energy regeneration. By combining the favorable factors, the optimization of energy consumption (down to 0.0089 Wh·g) could be achieved. As redox flow desalination has the benefits of a high energy efficiency and long lifespan (~20,000 cycles), together with the incorporation of energy recovery (over 80%), a robust future tendency of energy-efficient CDI desalination is expected.
电容去离子化（CDI）是一种新兴的环保脱盐技术，运行条件温和。然而，CDI的能耗尚未得到全面总结，这与经济成本密切相关。因此，本研究旨在回顾CDI文献中的能耗性能和机制，并揭示优化能耗的未来方向。CDI的能耗可能受到多种内部和外部因素的影响。采用离子交换膜、错流配置、恒流充电模式、较低的电场强度和流速、具有半选择性表面或高润湿性的电极材料以及氧化还原电解质是实现低能耗的优选因素。此外，通过能量再生，CDI中的能耗可以进一步降低。通过结合有利因素，可以实现能耗的优化（低至0.0089 Wh·g）。由于氧化还原液流脱盐具有高能效和长寿命（约20,000次循环）的优点，再加上能量回收（超过80%），预计CDI脱盐在节能方面将有强劲的未来发展趋势。
