Search results for "Reverse ElectroDialysis"

Geometrical characterization of reverse electrodialysis stack via CFD simulations

2012

In the presente work, CFD simulations were carried out in order to assess the effects of different parameters on the global process efficiency, such as the choice of spacer material and morphology, and the optimisation of feed and blowdown distribution systems

A novel Reverse Electrodialysis application to generate power from low-grade heat

2015

A novel idea for the conversion of low-temperature heat into electricity is based on the generation of electricity from salinity gradients using a Reverse Electrodialysis (RED) device in a closed-loop system. In this concept a limited amount of artificial saline solutions can be used as the working fluids in a closed-loop. The solutions exiting from the RED unit are then regenerated, in order to restore the original salinity gradient, by means of a separation step, which uses low-temperature heat (40-100°C) as its energy source. A theoretical analysis of potentials of this technology is illustrated in the present work.

Maximum Net Power Density Conditions in Reverse Electrodialysis Stacks

2018

Reverse Electrodialysis (RED) harvests electrical energy from a salinity gradient. The maximum obtainable net power density (NPD) depends on many physical and geometric variables. Some have a monotonic (beneficial or detrimental) influence on NPD, and can be regarded as “scenario” variables chosen by criteria other than NPD maximization. Others, namely the thicknesses HCONC, HDIL and the velocities UCONC, UDIL in the concentrate and diluate channels, have contrasting effects, so that the NPD maximum is obtained for some intermediate values of these parameters. A 1-D model of a RED stack was coupled here with an optimization algorithm to determine the conditions of maximum NPD in the space o…

A multi-scale model for the reverse electrodialysis process with seawater and concentrated brines

2012

Long-run operation of a reverse electrodialysis system fed with wastewater solutions

2016

In the framework of Salinity Gradient Power technologies, Reverse ElectroDialysis (RED) is one of the most promising. In RED, two solutions of different salt concentration are fed into a series of alternate compartments, the one fed by the low salinity solution, the other by the high salinity solution. Compartments are separated by anion and cation exchange membranes alternatively piled to form a stack. Selective ion transport from the concentrate compartment to the dilute one across the membranes allows to generate an ionic current, which is eventually converted into electric current by means of suitable electrode compartments closing the stack. Several options for the feed solutions are p…

Multi-physical modelling of Reverse ElectroDialysis

2016

Energy extraction from salinity gradients (salinity gradient power, SGP) represents a novel and valuable renewable energy source. Among the existing SGP technologies, reverse electrodialysis (RED) is the oldest and one of the most promising. RED is a membrane-based electrochemical process that directly converts the salinity gradient energy into electric current. More precisely, in a RED unit two solutions at different concentration flow in two series of alternated channels, which are formed by piling two alternated series of cation and anion exchange membranes (CEMs and AEMs, respectively). The chemical potential difference between the two solutions generates an electric potential differenc…

A multi-physics modelling tool for Reverse Electrodialysis

2015

In this work, a multi-physics modelling approach has been developed for the RED process.

Computational Fluid Dynamics of Reverse Electrodialysis Systems

Modelling Reverse Electrodialysis process via Exergy Analysis

2017

Salinity Gradient Power Heat Engines (SGP-HEs) represent a novel technology to convert low grade waste heat into electricity. Reverse Electrodialysis Heat Engine (REDHE) is one of the possible application of this concept, where a common RED unit is coupled with a thermal regeneration unit supplied with waste heat to restore the salinity gradient of the streams to be fed back to the RED unit. In a RED unit, anion and cation exchange membranes (AEMs and CEMs) are alternatively stacked and interposed between salt solutions at different concentration generating an electric potential difference over each membrane along with a selective transport of cations and anions from the concentrated soluti…

Exergy Analysis of Reverse Electrodialysis Heat Engine with Multi-Effect Distillation Regeneration Stage

2018

The increasing worldwide energy demand is rising the interest on alternative power production technologies based on renewable and emission-free energy sources. In this regard, the closed-loop reverse electrodialysis heat engine (RED-HE) is one of the most promising technologies currently under investigation. This technology produces electric power by harvesting the salinity gradient energy released from the controlled mixing of two artificial salt solutions with different concentrations. Low-grade heat (T < 100 °C), derived from any industrial process is used in a multi-effect distillation (MED) unit to restore the initial salinity gradient of the solutions. In this work, a comprehensive…