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Entropy 2013, 15(4), 1388-1407; doi:10.3390/e15041388

Capacitive Mixing for Harvesting the Free Energy of Solutions at Different Concentrations

3,*  and 1,*
1 Dipartimento di Scienze della Salute, Università di Milano-Bicocca, via Cadore 48, Monza (MB),Italy 2 ICFO-The Institute of Photonic Sciences, Av. Carl Friedrich Gauss, num. 3, Castelldefels, Spain 3 Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht,The Netherlands
* Authors to whom correspondence should be addressed.
Received: 18 March 2013 / Revised: 2 April 2013 / Accepted: 14 April 2013 / Published: 17 April 2013
(This article belongs to the Special Issue Entropy and Energy Extraction)
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An enormous dissipation of the order of 2 kJ/L takes place during the natural mixing process of fresh river water entering the salty sea. “Capacitive mixing” is a promising technique to efficiently harvest this energy in an environmentally clean and sustainable fashion. This method has its roots in the ability to store a very large amount of electric charge inside supercapacitor or battery electrodes dipped in a saline solution. Three different schemes have been studied so far, namely, Capacitive Double Layer Expansion (CDLE), Capacitive Donnan Potential (CDP) and Mixing Entropy Battery (MEB), respectively based on the variation upon salinity change of the electric double layer capacity, on the Donnan membrane potential, and on the electrochemical energy of intercalated ions.
Keywords: free energy; water salinity difference; capacitive mixing free energy; water salinity difference; capacitive mixing
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Rica, R.A.; Ziano, R.; Salerno, D.; Mantegazza, F.; van Roij, R.; Brogioli, D. Capacitive Mixing for Harvesting the Free Energy of Solutions at Different Concentrations. Entropy 2013, 15, 1388-1407.

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