Fully 3D Modeling of Electrochemical Deionization

Abstract

Electrochemical deionization devices are crucial for meeting global freshwater demands. One such is capacitive deionization (CDI), which is an emerging technology especially suited for brackish water desalination. In this work, we extend an electrolytic capacitor (ELC) model that exploits the similarities between CDI systems and supercapacitor/battery systems. Compared to the previous work, we introduce new implementational strategies for enhanced stability, a more detailed method of describing charge efficiency, layered integration of leakage reactions, and theory extensions to new material and operational conditions. Thanks to the stability and flexibility the approach brings, the current work can present the first fully coupled and spatiotemporal three-dimensional (3D) CDI model. We hope that this can pave the way toward generalized and full-scale modeling of CDI units under varying conditions. A 3D model can be beneficial for investigating asymmetric CDI device structures, and the work investigates a flow-through device structure with inlet and outlet pipes at the center and corners, respectively. The results show that dead (low-flow) areas can reduce desalination rates while also raising the total leakage. However, the ionic flux in this device is still enough under normal operating conditions to ensure reasonable performance. In conclusion, researchers will now have some flexibility in designing device structures that are not perfectly symmetric (real-life case), and hence we share the model files to facilitate future research with 3D modeling of these electrochemical deionization devices.

Enhanced Desalination Performance of Battery Electrode Deionization Based on the Optimized Design of Flow Channel Structure and Channel Section Reconstruction

“…It also reduces friction losses during fluid flow and reduces the amount of pumping energy required by the system, thus improving energy efficiency . Second, flow channel optimization can effectively reduce the stagnation area and dead space of the fluid within the flow channel, avoiding deposition or accumulation during solution flow, and facilitating the transfer of substances . In addition, flow channel optimization can also improve the performance of CDI and desalination as well as desalination efficiency, which can convert seawater into fresh water more efficiently. , This reduces the production cost of desalinated water and makes desalination more competitive and sustainable.…”