Title
Ion selectivity in multi-channel CDI: Permselectivity of porous carbon capacitive membrane electrodes used in multi-channel capacitive deionisation
Author
Vos, Ruben (TU Delft Mechanical Engineering)
Contributor
Hartkamp, Remco (mentor) 
Boon, N.J.H. (mentor)
Eral, H.B. (graduation committee)
Degree granting institution
Delft University of Technology
Programme
Mechanical Engineering | Energy, Flow and Process Technology
Date
2024-04-22
Abstract
Capacitive deionisation (CDI) is a desalination technology that removes ionic species from water through electrostatic attraction. Recently, a new CDI cell architecture has been developed with multiple channels and electrodes. Here, the ions are driven to migrate from channel to channel to desalinate the water. The inner electrodes of such a cell function as selective membranes when charged, therefore called capacitive membrane electrodes (CME). This thesis used an experimental approach to investigate the effect of the electrostatic charge and the microstructure of the CMEs on the permselectivity of these CMEs. Five different CMEs were tested in a cell to determine their permselectivities. A porometer (utilising the capillary flow technique) was used to determine the pore size distributions of the CMEs. When comparing the data from both measurements, it was found that CMEs with a higher fluid permeability also showed lower ionic resistances. A lower ionic resistance indicates a lower permselectivity. To achieve good desalination performance in multi-channel CDI, CMEs must offer low ionic resistance when ions are driven from low salinity to high salinity, while still being permselective when ions want to migrate back from high to low salinity.
Subject
Desalination
Capacitive Deionization
Porous electrode
selectivity
Pore size distribution
To reference this document use:
http://resolver.tudelft.nl/uuid:725d016b-77e3-4423-8e57-fbd50f4858b2
Embargo date
2025-04-22
Part of collection
Student theses
Document type
master thesis
Rights
© 2024 Ruben Vos