Development of a two-dimensional coupled-implicit numerical tool for analysis of the CDI operation

Capacitive deionization, CDI, is an economical desalination technology which has drawn much attention and progress recently. A tool to extend a pore model into an electrode model was developed for CDI simulation based on a single pore simulation model. By comparing two Biesheuvel's experimental data with the tool result, diffusion coefficients inside electrode pores during a salt removal phase and electrode recovery phase were found to be order of 0.001 and 0.1 of bulk values, respectively. The predictions from the present tool agreed well with the experimental outlet concentration and current profiles. A sensitivity study was performed to identify the effects of retention time, pore depth, and capacitance on product water. The results confirmed that a large retention time, large pore depth and higher capacitance provide better performance. (C) 2012 Elsevier B.V. All rights reserved.