A new open access paper was recently published in Desalination that compares the energy use of RO and CDI.
Porada et al. “Energy consumption in membrane capacitive deionization and comparison with reverse osmosis”, Desalination (2020), https://doi.org/10.1016/j.desal.2020.114383.
According to the authors, "the work presents the first fair energy consumption comparison of desalination with MCDI and RO. The comparison is based on experimental data, and the data is compared with results from state-of-the-art theoretical models. We find that the energy consumption difference between RO and CDI is much less than recently reported by the group of Prof. Elimelech (Yale, USA), see weblink."
The authors emphasize that two technologies can only be compared when all metrics are used in the same uniform way, and when for each technology state-of-the-art is considered. A new operational mode for CDI is introduced with a long "hold time" during salt release, leading to unprecedented high values of water recovery obtained in CDI with high feed water salinity of 40 mM NaCl solution.
We are honored to introduce the 5th International conference on capacitive deionization and electrosorption, which will take place in Atlanta, GA, United States on May 11th-14th, 2021. The conference will be a good forum for CDI researchers to present new results, draw inspiration, and direct future growth into CDI&E research. We would be grateful for your attendance and participation in this event. To stay up to date with conference preparations, please see our conference website (https://www.cdie2021.com/) or follow us on Twitter (@CDIe_2021).
You can read the December 2019 newsletter here.
The December newsletter includes highlights on:
- Our upcoming conference, which will be hosted at Georgia Tech, Atlanta, USA, in May 2021
- CDI & Electrosorption 2019 conference
You can register for our newsletter on our website (right column).
Last week’s conference in Beijing was a great success! 200 scientists met in Beijing and discussed the latest scientific and industrial developments in the field of Capacitive Deionization. The 4-day conference started on Monday with three tutorials on theory, cell architectures and metrics by renowned professors. Thereafter, the scientific part of the program started, with many talks on operation, materials design, ion selective removal & recovery and the industrial application of CDI technology. The conference was hosted by Prof. Peng Liang from the School of Environment of Tsinghua University, and due to his tremendous efforts and the excellent support by his students, all scientists and industrial partners had an amazing week in Beijing!
We are honored to introduce the 4th International conference on Capacitive Deionization and Electrosorption, which will take place in Beijing, China, from May 20 to 23, 2019. The conference will be a good forum for CDI researchers to present the latest results, to draw inspiration and ideas, and to probe into the future development of CDI&E technologies. Twenty eight renowned scientists have confirmed as keynote or invited speaker. Moreover, more than 100 abstracts have already been submitted. Please visit our website for detailed information: http://cdi-e2019.csp.escience.cn/dct/page/70006.
You can still submit an abstract for an oral and/or poster presentation. The deadline for submission has been extended to November 30th, 2018.
Also, early registration is open from November 1st, 2018 to February 28th, 2019. More information related to the conference will be posted on the website soon.
The upcoming 3rd world conference on CDI&E "Capacitive Deionization, Electrosorption, and Electrodialysis" will be held July 3-6, 2017, in Seoul, Republic of Korea. Following earlier conferences in The Netherlands and Germany, we expect an attendance of over 200 delegates discussing all aspects of water treatment and desalination using electrochemical methods based on porous electrodes and/or ion-exchange membranes, from materials science and theoretical studies, to process engineering and commercial successes.
The conference website is: http://www.cdi-e2017.com
The CDI-E working group is looking forward to welcoming you in July 2017 in Seoul, Republic of Korea !
Other CDI-related conferences in 2017 can be found here
Currently CDI devices
consume significantly more energy than the theoretical thermodynamic minimum, and this is partly due to resistive power
dissipation. To enhance the performance of CDI, identification of resistances in the CDI cell is important. Recently, two articles have been published on characterizing resistances in CDI and membrane-CDI (MCDI).
Researchers from Stanford University (US) published an article in Environmental Science and Technology. They characterize electrical resistances in a CDI system, present an equivalent circuit model and propose measurable figures of merit to describe cell resistance. They also found that contact resistance between current collectors and porous electrodes is the major contributor to cell resistance in nearly all published CDI cells. Contact resistance can be reduced by either introducing contact pressure between current collectors and electrodes or using pore-filling adhesive to create a point contact configuration. They emphasize here that energy consumption of the CDI process is the unrecoverable dissipated energy during an operation cycle, which should not include stored capacitive energy.
Researchers from Wageningen University and Wetsus (The Netherlands) published an article in Water Research. They outline a method to identify electronic and ionic resistances. They illustrate their method by calculating the resistances in an MCDI cell, for which they derived a full-scale model. This model is validated against experimental data and used to calculate the ionic resistances across the MCDI cell. Furthermore, they present a way to measure ionic and electronic resistances in a CDI cell, as well as establish the spacer channel thickness and porosity after assembly of the MCDI cell. Based on their findings, they show that, for MCDI, the carbon electrode thickness can be increased without significantly increasing energy consumption, which has the advantage that desalination time can be lengthened significantly.
* Y. Qu, T.F. Baumann, J.G. Santiago, M. Stadermann, Characterization of Resistances of a Capacitive Deionization System, Environ Sci Technol, 49 (2015) 9699-9706.
* J.E. Dykstra, R. Zhao, P.M. Biesheuvel, A. van der Wal, Resistance identification and rational process design in Capacitive Deionization, Water Research, 88 (2016) 358-370.
October 25-29, 2015, the International Conference on CDI&Electrosorption was organized by the Institute of New Materials (INM) in Saarbrücken, Germany. In a beautiful location on the pittoresque campus of Saarland University, 120 attendees from all around the globe participated in lectures, a CDI-tutorial, and a poster session, with lively discussions during coffee breaks and lunches. An inspiring and diverse program was organized by the conference chair prof. Volker Presser (INM) and co-chair prof. Matthew Suss (Technion, Israel). Many new contacts were made during the opening mixer, the memorable excursion to an old steel and coal factory, and during the delicious gala dinner. We look back at a wonderful and very successful CDI&Electrosorption conference.
For our upcoming CDI&E conference, organized by Prof. Dr. Volker Presser (INM) and Prof. Dr. Matthew Suss (Technion), to be held in Saarbrücken, 26-29 October 2015, the flyer is available now !
A direct link to the conference website is www.cdi2015.de where you can submit your abstract for an oral or poster presentation. The conference registration has opened as well - note that the number of participants is limited, and thus make sure you register in time !
The abstract submission deadline is set to June 19, 2015.
In an American-Israel-Dutch-Polish cooperation, the existing "normal" modified-Donnan model to describe the electrical double layer structure in (micro-)porous carbons, was significantly improved (ergo: the i-mD model) without jeopardizing the model's mathematical simplicity, allowing it to be incorporated in transport theory, and allowing it to be solved using simple spreadsheet-software such as Excel. This i-mD model was published in a special issue of the Journal of Solid State Electrochemistry, commemorating the late prof. V.S. Bagotsky. The i-mD model has the same advantage as the classical mD-model (developed in 2011 for CDI) namely that it is mathematically simple and can be used for transport modeling in porous carbons (note that the Gouy-Chapman-Stern theory will fail for sufficiently small pores, as the inherent pore overlap is not included in GCS theory), but in addition describes salt adsorption at high salinity much better. This was a weak point of the "normal" mD-model. The improvement consists of a slightly different formulation, not introducing more mathematical "fit"-parameters, and actually, the new model has a strong physical background, based on attractive ion-ion correlation forces. Prof. Martin Bazant (MIT), the senior author of the paper, comments "It is quite remarkable how such a simple model fits data so beautifully. I was very surprised myself. As far as I know, the simple form of the ion correlation force expression that we present, is new. Possibly in the future we will find out if we need a more accurate expression, but for the moment this simple model works like a charm, and it has a physical basis which has the advantage that further extensions such as considering the case of ionic mixtures becomes possible."
link to the journal
PDF via ResearchGate