Search results for " electrodialysis"

Improving efficiency and discharge power of acid-base flow battery via a bi-objective optimisation

2023

Optimization of net power density in Reverse Electrodialysis

2019

Abstract Reverse Electrodialysis (RED) extracts electrical energy from the salinity difference between two solutions using selective ion exchange membranes. In RED, conditions yielding a large net power density (NPD) are generally desired, due to the still large cost of the membranes. NPD depends on a large number of physical and geometric parameters. Some of these, for example the inlet concentrations of concentrate and diluate, can be regarded as “scenario” variables, imposed by external constraints (e.g., availability) or chosen by different criteria than NPD maximization. Others, namely the thicknesses HCONC, HDIL and the velocities UCONC, UDIL in the concentrate and diluate channels, c…

The REAPower Project

2019

Abstract Reverse electrodialysis technology has grown significantly in the last decade, gaining a fast increase in its technology readiness level and presenting some interesting examples of pilot systems operating under very different real environments. Among these, one was able to operate in a saltwork in Marsala (Sicily, Italy) with real concentrated brine and real saline waters (i.e., either seawater or brackish water), producing electric power in the order of 1 kW. This pilot plant was one of the main achievements of the European REAPower research project. This chapter presents an overview of the main research efforts and results achieved in the framework of this project starting from t…

Cathodic abatement of Cr(VI) in water by microbial reverse-electrodialysis cells

2015

Abstract For the first time a microbial reverse electrodialysis cell (MRC) was used for the treatment of water contaminated by Cr(VI). It has been recently shown that both inorganic and organic pollutants can be removed by reverse electrodialysis processes (RED) using water with different salinity without the supply of electric energy. However, a high number of membrane pairs is usually necessary for the treatment of wastewater by RED. Here, it was showed that a lower number of membranes can be used by the utilization of a MRC (i.e., a RED cell with a biotic anode) for such purposes. Indeed, the abatement of Cr(VI), chosen as model pollutant, was successfully achieved by cathodic reduction …

CFD prediction of concentration polarization phenomena in spacer-filled channels for Reverse Electrodialysis

2014

Abstract Salinity Gradient Power generation through Reverse Electrodialysis (SGP-RE) is a promising technology to convert the chemical potential difference of a salinity gradient into electric energy. In SGP-RE systems, as in most membrane processes, concentration polarization phenomena may affect the theoretical driving force and thus the performance of the process. Operating conditions, including the feed solution flow rate and concentration and the channels׳ geometrical configuration, may greatly influence both the polarization effect and the pumping energy consumption. The present work uses CFD to investigate the dependence of concentration polarization and pressure drop on flow rate, f…

SELECTION OF REDOX SYSTEMS FOR REVERSE ELECTRODIALYSIS PROCESSES

2012

In reverse electrodialysis (RED) processes, electrical energy is directly extracted from chemical potential gradients arising from salinity differences, especially from sea and river water. In RED there are at least four complementary elements: (1) electrodes, where electron transfer reactions occur to allow the transformation of the charge carrier from ion to electron; (2) ion selective exchange membranes, which allow the selective transport of ions; (3) solvents, which make a continuum for ion transport; (4) electrolytes, i.e. the current carriers between cathode and anode. Studies on RED processes were mainly focused on membranes but also on several other aspects including electrolyte co…

Investigation of electrode material - redox couple systems for reverse electrodialysis processes

2012

Towards the simultaneous generation of electric energy and the abatement of organic pollutants by reverse electrodialysis processes

2012

In reverse electrodialysis (RED) processes, electrical energy is directly extracted from chemical potential gradients arising from salinity differences, especially from sea and river water [1]. In RED there are at least four complementary elements: (1) electrodes, where electron transfer reactions occur to allow the transformation of the charge carrier from ion to electron; (2) ion selective exchange membranes, which allow the selective transport of ions; (3) solvents, which make a continuum for ion transport; (4) electrolytes, i.e. the current carriers between cathode and anode. The redox process is usually chosen in order to limit the energetic losses, the cost of redox specie and electro…

REVERSE ELECTRODIALYSIS PROCESSES FOR THE PRODUCTION OF CHEMICALS AND THE TREATMENT OF CONTAMINATED WASTEWATER

ABATEMENT OF POLLUTANTS IN AQUEOUS SOLUTIONS BY REVERSE ELECTRODIALYSIS PROCESSES

2013

Electrochemistry-based technologies are very promising methods for treating wastewaters containing organic and inorganic pollutants that are either resistant to biological processes or toxic for microorganisms [1]. On the other hand, in the reverse electrodialysis (RED), the electrical energy is directly extracted from chemical potential gradients arising from salinity differences [2], especially between brine solution and sea water. RED can be potentially used for the simultaneous generation of electrical energy and the treatment of waters contaminated by recalcitrant pollutants. The advantages of using the RED process for such dual purpose are: the utilization of a green reagent such as t…