Electrochemical desalination of seawater technology

24 May 2023
Desalación de agua de mar por batería

“TECNALIA develops a battery desalination technology that significantly reduces seawater desalination energy consumption”

New alternatives to optimise available water are being researched due to droughts and the increasing demand of water for crops.

TECNALIA is developing and validating battery desalination technology based on an electrochemical process of sequential oxidation and reduction of the electrodes (charge-discharge cycle), and the use of an ion-conducting membrane.

The first experimental results at laboratory cell level have shown that the technical solution that is used, which includes an energy recovery process, is able to achieve lower energy consumption for seawater desalination than current industrial technologies.

Possible configurations for scaling up this technology have also been studied in order to move forward in the analysis of its potential industrial application.

Prototype design and manufacturing

The final goal of this project is to design and manufacture a seawater desalination system prototype: it has been installed and tested at the facilities of the Canary Islands Institute of Technology (ITC) in Pozo Izquierdo, Gran Canaria.

This prototype integrates a set of electrochemical desalination cells with a specific geometry and composition of electrodes and components. The energy recovery concept developed for these cells significantly reduces the energy consumption of the desalination system.

The prototype also includes a control and data communication system that enables the system to be operated remotely by setting different process conditions. It also provides accurate information about its operation and the energy performance and consumption values that are achieved.

A more energy-efficient option

This technology, based on the concept of battery operation to extract salts from aqueous solutions, aims to be an energy-efficient option for water desalination, compared to currently common technologies such as reverse osmosis.

Unlike reverse osmosis, this technology do not require high inlet water pressures, and has lower operating costs.

Furthermore, the percentage of water recovered after the desalination process can be up to 80-90 % of the treated water (compared to 50% with reverse osmosis), reducing brine generation to only 10-20 %.

Innovative technology development

These developments have been carried out through a pre-commercial public procurement for the development of innovative technology, funded by the Island Council of Gran Canaria and managed by the Canary Islands Institute of Technology. It is part of the experimental and comprehensive programme of R&D&I activities linked to the exploitation of island marine resources under a collaboration agreement with the Ministry of Science and Innovation.