Evaluation of fluid flow in continuous electro-deionization (CEDI) module through computational fluid dynamics (CFD) analysis

Abstract

Since high quality/density of semiconductor has been needed by growing up the semiconductor industry, there has been a key-point that technologies of ultra-pure water (UPW) production become a critical component. However, there is still lack of technologies of modules and materials for producing UPW in Korea, it should depend on foreign country inevitably. Among these technologies of UPW production, continuous electro-deionization (CEDI) has been emerged as an important component. CEDI is composed of cross-arranged selective permeable ion-exchange membrane and spacer with ion-exchange resin, which is for ion separation and for increasing ion transfer, respectively. Removing infinitesimal concentration of ion, UPW can be produced through ion separation under voltage of direct current on CEDI, so that could be an essential component. However, fluid flow in CEDI can be changed with modification of spacer structure, following that can affect mass transfer and decreasing ion removal efficiency. Fluid flow in CEDI can be analyzed by modeling and simulation through computational fluid dynamics. Therefore, in this study, mass transfer of ion-exchange resin in CEDI spacer was evaluated and spacer modification for optimizing mass transfer and ion removal was suggested. Also, fluid flow in several section of CEDI spacer with and without ion-exchange resin was analyzed to assess the role of ion-exchange resin. With this optimized spacer from this study, removal of infinitesimal amount of ion could be enhanced by CEDI and can contribute to localize technologies of CEDI.