Optimization of the intermediate chamber improves desalination performance in flow electrode capacitive deionization (FCDI): A comparative study

• Published in: Desalination Vol. 584; p. 117743
• Main Authors: Li, Yunke, Yang, Chenxu, Chen, Meng, Bian, Yonghuan, Niu, Jianrui, Mu, Situ, Zhang, Jing, Liu, Chun, Ma, Junjun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 12-09-2024
• Subjects: Computational fluid dynamics; Energy consumption; Flow electrode capacitive deionization; In situ potential measurements; Intermediate chamber; Intermediate chamber; In situ potential measurements; Energy consumption; Computational fluid dynamics; Flow electrode capacitive deionization
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2024.117743

Flow electrode capacitive deionization (FCDI), a novel ion removal technology, is influenced by various factors such as electrode material properties, fluid flow rate, and device structure. In the FCDI system, the intermediate chamber is the core element where ions migrate towards the cathode and anode to complete the adsorption process. In this study, we designed a hollow plastic plate with channels (PP) and a hollow graphite plate with channels (GP) as the intermediate chamber, compare and study with conventional plastic mesh (PM) chambers. CFD simulations revealed that the newly designed PP and GP chambers significantly reduced the hydraulic stagnation zone. The results of the desalination experiments revealed that the desalination efficiency of the GP-FCDI was 1.5 and 1.9 times higher than that of the PP-FCDI and PM-FCDI, respectively. At the same time, in situ potential measurement (ISPM) was used to monitor the voltage drop of each component in FCDI, thereby accurately calculated the proportion of energy consumption in the intermediate chamber. The results indicate that the energy consumption of the intermediate chamber of GP-FCDI was 54 % less than that of PM-FCDI. The current work will help us provide new insights for the design and optimization of FCDI systems.
•Replaced conventional FCDI intermediate chamber with flow channel•Innovative introduction of graphite plate into the intermediate chamber•The effects of hydraulic distribution on desalination performance were analyzed.•The SEC of each component of the FCDI device was calculated separately.