A new Open Access paper was published in the prestigious journal ES&T, from the group of prof. Meny Elimelech (Yale, USA) which discusses a detailed comparison between electrodialysis (ED) and membrane capacitive deionization (MCDI).
Patel et al. "Energy Efficiency of Electro-Driven Brackish Water Desalination: Electrodialysis Significantly Outperforms Membrane Capacitive Deionization", ES&T (2020). https://pubs.acs.org/doi/abs/10.1021/acs.est.9b07482
According to the authors, "we provide the first systematic and rigorous comparison of the energetic performance of electrodialysis (ED) and membrane capacitive deionization (MCDI) over a broad range of brackish water desalination conditions."
The authors find that:
- The energy consumption of ED is substantially lower than MCDI for all investigated conditions, with the energy efficiency being nearly an order of magnitude higher for many separations.
- Even with idealized operation (complete energy recovery and reduction in energetic losses), the energy efficiency of MCDI remains lower than ED.
Finally, the authors emphasize that "for low feedwater salinities (< ~2 g/L), energy efficiency should be a secondary consideration in the choice of desalination technology, with capital cost, ease and reliability of operation, and additionally required treatment steps taking higher priority."
... and the field of Capacitive Deionization keeps on growing at an increasing speed ! With over 160 scientific papers written and published last year, the total number of CDI publications has grown from ∼25 in 2000, to ∼65 in 2010, to over 1,000 at the end of 2019! CDI papers in 2019 came from many prestigious places including Tsinghua University, Seoul National University, Technion, MIT, Stanford, and Yale. This output from such eminent research groups shows that CDI is taking a leading role in the scientific study of water desalination technologies. Analyzing these publication data for the past decade, an exponential growth can be observed, with a doubling of the publication output every 2.5 year !
Citations to the CDI literature have grown from a number less than 100 per year before 2010, to about 2000 per year at the end of 2015, and close to 10,000 per year in 2019. These statistics also reflect an exponential growth, with a doubling time of 2.0 year. This difference in doubling time (faster for citations than publications) may indicate that CDI papers are more and more cited in papers from outside the CDI-field.
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.
Following the CDI conference recently held in the Republic of Korea, July 2017, twenty scientists active in the field of CDI worked on a joint position paper, putting forward the proposition that CDI defines a class of desalination technologies that share common operational principles and relevant metrics, thereby joining under one common term different CDI cell layouts and chemistries. Thus, according to the position paper, the class of CDI includes electrodes based on carbon materials, but as well electrodes with ion storage based on different chemistries such as using redox materials. The position paper can be downloaded via the link given below.
P.M. Biesheuvel, M.Z. Bazant, R.D. Cusick, T.A. Hatton, K.B. Hatzell, M.C. Hatzell, P. Liang, S. Lin, S. Porada, J.G. Santiago, K.C. Smith, M. Stadermann, X. Su, X. Sun, T.D. Waite, A. van der Wal, J. Yoon, R. Zhao, L. Zou, and M.E. Suss, "Capacitive Deionization -- defining a class of desalination technologies," ArXiv:1709.05925 (2017).
Last week's CDI-E's conference was a big success. 180 participants gathered for three full conference days in the heart of Seoul, Republic of South Korea. The conference, hosted by prof. Jeyong Yoon and his team of Seoul National University, proved invaluable in informing participants of all the latest developments in CDI technology, both from an academic and industrial perspective. The versatile program consisted of a tutorial session, plenary and keynote lectures, regular lectures and two poster sessions and gave food for thought to all attendants. The lively and amiable atmosphere gave the whole conference the right touch of feeling welcome in perhaps one of the most vibrant places in the world, the famous Gangnam district, a place that never sleeps.
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
Two recent papers with authors from the US, The Netherlands, and Israel, convincingly show the relevance of chemical charge residing in the carbon electrodes ("immobile", or "complementary" charge) to enhance salt adsorption capacity (SAC) of CDI electrodes.
In the more theoretical paper of the two, published OPEN ACCESS in Colloids and Interfaces Science Communications, the theoretical framework is laid out which comprehensively describes the range of recently developed new CDI desalination modes such as inverted-CDI and (what the authors call) enhanced-CDI. Also the occurrence of "inversion peaks" which often develop during normal CDI operation are explained as due to developing chemical charge. In addition, a novel operational mode is described where due to the chemical charge, it becomes possible to enlarge the operating window of CDI and thus to enhance SAC further still. This operational mode of "extended voltage CDI" was not described before.
In the sequel paper, published in Water Research, both the enhanced-CDI regime and the extended-voltage CDI-regime are experimentally validated. In this paper the more advanced amphoteric Donnan model is used to describe the EDL-structure. This model quantitatively predicts the experimental observations of salt storage and charge. An interesting inconsistency is how the measured chemical charge (by titration) can be up to one order beyond the chemical charge derived from comparing the amph-D model to the data.