2D Simulations of Water Treatment with Upscaled Capacitive Deionization

Abstract

Clean water is a major global challenge. Meanwhile, capacitive deionization (CDI) is an emerging desalination technology that could help produce and reuse water. As the technology develops, the modeling of upscaled systems is becoming increasingly relevant. However, the inherent complexities in the CDI process have historically made such simulations unfeasible. In this work, we leverage the newly published electrolytic-capacitor (ECL) model to efficiently simulate parallel/serial flow modes in CDI stacks. The simulations are based on finite-element methods (FEM) that couple differential equations for describing local charging and ionic transport inside the device. The results show that both parallel and serial connections scale incredibly well with the system size. Still, parallel connections have the advantage of requiring lower pumping energy. Overall, we find that the relationship between adsorption capacity, flowrate, and compartment size is a good indicator of performance. In conclusion, the ELC model is promising for simulating upscaled CDI.

Numerical Investigation of Flow Arrangement in Battery Electrode Deionization Stacks with Configurations of Plate Heat Exchangers

“…In summary, the BDI stack can commonly be divided into series and parallel. − They can also be distinguished by the method of arrangement between electrodes. ,− In the series stack, the incoming water is continuously pumped to the downstream stack. This means that the downstream cells can treat only brine that has been treated by the upstream cells.…”