Electrophysical characteristics of the desalination plant based on the principle of capacitive deionization

The basic electrophysical and technological parameters of a CDI desalination plant designed for long-term operation, based on the principle of salt solution deionization on electrodes with a developed surface, have been studied. The proposed equipment for water demineralization uses a simplified design with pumping the solution through electrodes (“flow through electrodes”), which allows bypassing without relatively expensive ion-exchange membranes. Non-woven felt “Karbopon-V-Aktiv-200-65A” was used as the electrode material, the estimated value of the specific surface of the material of which, according to the results of measurements by the method with the deposition of acetone, amounted to ~ 1000 m2/g or more. Also, the advantages of the proposed CDI desalination plant are the absence of highly loaded power elements, the use of corrosion-resistant materials and the reliability of the electrode stacking scheme, which makes it possible to count on its long-term and reliable operation. Various possibilities of operational adjustment of the desalination plant modes are demonstrated – reduction of the discharge period due to the application of voltage pulses of reverse polarity, increasing efficiency by organizing a procedure for taking into account the real voltage at the working electrodes inside the CDI cell. The high-energy efficiency of demineralization is determined by the relatively low operating voltage of ~ 1 V. It is established that with increasing amperage, salt removal is more efficient, respectively, the degree of desalination is higher at a higher current: the working period of 30 minutes corresponds to the degree of desalination of ~ 20 % at a voltage of 1.4 V and ~ 30 % in the 1.6 V mode. The possibility of increasing the desalination capacity to ~ 100 g of salt over a half-hour period was noted. Possible ways to further improvement of the performance of the equipment presented in the article are identified.

desalination, saline solution, volume deionization, porous electrode, ion sorption, degree of desalination, energy efficiency

1. Urazaev V. Review of water purification methods. Tekhnologii v elektronnoi promyshlennosti = Technologies in the Electronics Industry, 2007, no. 2, pp. 72–79 (in Russian).

2. Biesheuvel P. M., Bazant M. Z., Cusick R. D., Hatton T. A., Hatzell K. B., Hatzell M. C., Liang P., Lin S., Porada S., Santiago J. G., Smith K. C., Stadermann M., Su X., Sun X., Waite T. D., Van der Wal A., Yoon J., Zhao R., Zou L., Suss M. E. Capacitive Deionization – defining a class of desalination technologies. 2017. Available at: https://arxiv.org/abs/1709.05925 (accessed 10 August 2019).

3. Porada S., Zhao R., Wal A. van der, Presser V., Biesheuvel P. M. Review on the science and technology of water desalination by capacitive deionization. Progress in Materials Science, 2013, vol. 58, iss. 8, pp. 1388–1442. https://doi.org/10.1016/j.pmatsci.2013.03.005

4. Suss M. E., Porada S., Sun X., Biesheuvel P. M., Yoon J., Presser V. Water desalination via capacitive deionization: what is it and what can we expect from it? Energy & Environmental Science, 2015, vol. 8, iss. 8, pp. 2296–2319. http://dx.doi.org/10.1039/C5EE00519A

5. Eletskii А. V., Zitserman V. Y., Kobzev G. A. Nanocarbon materials: Physical-chemical and performance properties, synthesis methods, and energy applications. High Temperature, 2015, vol. 53, no. 1, pp. 130–150. https://doi.org/10.1134/S0018151X15010034. (in Russian).

6. Candelariaa S. L., Yuyan Shaob, Zhouc Wei, Lib Xiaolin, Xiao Jie, Zhangb Ji-Guang, Wang Yong, Li Jun, Lic Jinghong, Cao Guozhong. Nanostructured carbon for energy storage and conversion. Nano Energy, 2012, vol. 1, no. 2, pp. 195–220.https://doi.org/10.1016/j.nanoen.2011.11.006

7. Mikhalin A. A. Research of capacitive and electrokinetic properties of electrodes based on highly dispersed carbon as applied to their use in supercapacitors and for capacitive deionization of water. Мoscow, 2013. 164 p. (in Russian).

8. Rychagov A. Yu., Wolfkovich Yu. M., Vorotyntsev M.A., Kvacheva L. D., Konev D. V., Krestinin A. V., Kryazhev Yu. G., Kuznetsov V. L., Kukushkina Yu A., Mukhin V. M., Sokolov V. V., Chervonobrodov S. P. Promising carbon materials for supercapacitors. Elektrokhimicheskaya energetika = Electrochemical Energetics, 2012, vol. 12, no. 4, pp. 167–180 (in Russian).

9. Kim T., Gorski C. A., Logan B. E. Low Energy Desalination Using Battery Electrode Deionization. Environmental Science & Technology Letters, 2017, vol. 4, iss. 10, pp. 444–449. https://doi.org/10.1021/acs.estlett.7b00392

10. Ahmada F., Khana S. J., Jamala Y., Kamrana H., Ahsana A., Ahmada M., Kha A. Desalination of brackish water using capacitive deionization (CDI) technology. Desalination and Water Treatment, 2015, vol. 57, iss. 17. https://doi.org/10.1080/19443994.2015.1037357

11. Zhdanok A. S., Chervyak A. G., Shushkov S. V., Alotaibi Zaid S., Alharbi Yaseen G. Method for reducing the desalination time in a “flow-through” CDI-water clearance equipment. Vestsi Natsyyanal’nai academii navuk Belarusi. Seryya fizika-technichnych navuk = Proceedings of the National Academy of Sciences of Belarus. Physical-technical series, 2018, vol. 63, no. 4, pp. 444–454 (in Russian). https://doi.org/10.29235/1561-8358-2018-63-4-444-454.

12. Dykstra J. E., Zhao R., Biesheuvel P. M., Wal A. van der. Resistance identification and rational process design in Capacitive Deionization. Water Research, 2016, vol. 88, pp. 358–370. https://doi.org/10.1016/j.watres.2015.10.006

13. Qu Yatian, Baumann T. F., Santiago J. G., Stadermann M. Characterization of Resistances of a Capacitive Deionization System. Environmental Science & Technology, 2015, vol. 49, iss. 16, pp. 9699–9706. https://doi.org/10.1021/acs.est.5b02542

14. Pernía A. M., Álvarez-González F. J., Díaz J., Villegas P. J. and Nuño F. Optimum Peak Current Hysteresis Control for Energy Recovering Converter in CDI Desalination. Energies, 2014, vol. 7, no. 6, pp. 3823–3839. https://doi.org/10.3390/en7063823

15. Astafiev E. A. Production and supply of devices for electrochemical research. Available at: https://docplayer.ru/31816395-Chto-takoe-potenciostat-i-kak-im-pravilno-polzovatsya.html (accessed 06 November 2019) (in Russian).

16. Estpure: Water is the sourse of life. Available at: http://www.estpure.com/index.php/zbtz.html (accessed 10 September 2019).