Search results for "Reverse electrodialysi"

showing 10 items of 101 documents

Investigation of Reverse ElectroDialysis Units by Multi-Physical Modelling

2016

Reverse electrodialysis (RED) is an electrochemical membrane process that converts the salinity gradient energy between two solutions into electric current, by using ion exchange membranes. A novel multi-physical approach for RED modelling is proposed. 2-D simulations of one cell pair with tertiary current distribution (Nernst–Plank equation and local electroneutrality) were performed. Moreover, the Donnan exclusion theory was implemented for simulating double layer phenomena. Transport phenomena and electrochemical behavior were well described. The influence of membrane/channel configuration, dilute concentration and feeds velocity on the process performance was assessed. For a dilute conc…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciSettore ING-IND/25 - Impianti ChimiciSettore ING-IND/06 - FluidodinamicaReverse electrodialysis multi-physics profiled membranes spacersSettore ING-IND/19 - Impianti Nucleari
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Flow and mass transfer in spacer-filled channels for reverse electrodialysis: a CFD parametrical study

2016

Abstract In reverse electrodialysis (RED) concentration polarization phenomena and pressure drop affect strongly the power output obtainable; therefore the channel geometry has a crucial impact on the system optimization. Both overlapped and woven spacers are commonly commercialised and adopted for RED experiments; the latter exhibit some potential advantages, such as better mixing and lower shadow effect, but they have been poorly investigated in the literature so far. In this work, computational fluid dynamics was used to predict fluid flow and mass transfer in spacer-filled channels for RED applications. A parametric analysis for different spacer geometries was carried out: woven (w) and…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciSpacer-filled channelSettore ING-IND/25 - Impianti ChimiciMixing (process engineering)Filtration and Separation02 engineering and technologyCFD; Concentration polarization; Mass transfer; Reverse electrodialysis (RED); Spacer-filled channel; Physical and Theoretical Chemistry; Materials Science (all); Biochemistry; Filtration and SeparationBiochemistryProtein filamentsymbols.namesake020401 chemical engineeringReversed electrodialysisMass transferFluid dynamicsGeneral Materials ScienceMass transfer0204 chemical engineeringPhysical and Theoretical ChemistryConcentration polarizationSettore ING-IND/19 - Impianti NucleariConcentration polarizationPressure dropSettore ING-IND/24 - Principi Di Ingegneria ChimicaChromatographyChemistryReverse electrodialysis (RED)Reynolds numberMechanics021001 nanoscience & nanotechnologysymbolsMaterials Science (all)0210 nano-technologyCFD
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Reverse electrodialysis with NH4HCO3-water systems for heat-to-power conversion

2017

Abstract A Reverse ElectroDialysis Heat Engine (REDHE) system operating with “thermolytic” ammonium hydrogen-carbonate (NH4HCO3) aqueous solutions as working fluids is studied. The engine is constituted by (i) a RED unit to produce electric power by mixing the solutions at different salinity and (ii) a thermally-driven regeneration unit including a stripping and an absorption column to restore the initial salinity gradient thus closing the cycle. In the present work only the RED unit and the stripping column are taken into account. In particular, a simplified integrated process model for the whole cycle was developed: it consists of (i) a lumped parameter model for the RED unit validated wi…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciStripping (chemistry)Salinity gradient power (SGP)020209 energyAnalytical chemistry02 engineering and technology7. Clean energyThermolytic saltIndustrial and Manufacturing EngineeringWaste heat recovery unitReversed electrodialysisThermal0202 electrical engineering electronic engineering information engineeringElectrical and Electronic EngineeringClosed-loop reverse electrodialysiWaste heat recoveryAmmonium hydrogen carbonateCivil and Structural EngineeringPower densityHeat engineWaste managementChemistryMechanical EngineeringAmmonium hydrogen carbonate; Closed-loop reverse electrodialysis; Reverse ElectroDialysis Heat Engine (REDHE); Salinity gradient power (SGP); Thermolytic salts; Waste heat recovery; Civil and Structural Engineering; Building and Construction; Pollution; Energy (all); Mechanical Engineering; Industrial and Manufacturing Engineering; Electrical and Electronic EngineeringBuilding and ConstructionElectrodialysis021001 nanoscience & nanotechnologyPollution6. Clean waterEnergy (all)General EnergyReverse ElectroDialysis Heat Engine (REDHE)Electric power0210 nano-technology
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Bipolar membrane reverse electrodialysis for the sustainable recovery of energy from pH gradients of industrial wastewater: Performance prediction by…

2021

Abstract The theoretical energy density extractable from acidic and alkaline solutions is higher than 20 kWh m−3 of single solution when mixing 1 M concentrated streams. Therefore, acidic and alkaline industrial wastewater have a huge potential for the recovery of energy. To this purpose, bipolar membrane reverse electrodialysis (BMRED) is an interesting, yet poorly studied technology for the conversion of the mixing entropy of solutions at different pH into electricity. Although it shows promising performance, only few works have been presented in the literature so far, and no comprehensive models have been developed yet. This work presents a mathematical multi-scale model based on a semi-…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciWork (thermodynamics)pH gradient energyEnvironmental Engineering0208 environmental biotechnologyMixing (process engineering)02 engineering and technologyWastewater010501 environmental sciencesManagement Monitoring Policy and Law01 natural sciencesIndustrial wastewater treatmentElectricityRiversion-exchange membraneReversed electrodialysisPerformance predictionProcess engineeringelectro-membrane proceWaste Management and Disposal0105 earth and related environmental sciencesPower densitybusiness.industryProton-Motive ForceMembranes Artificialbipolar membrane reverse electrodialysisGeneral Medicinewastewater valorisation020801 environmental engineeringMembraneEnvironmental sciencebusinessEfficient energy useJournal of Environmental Management
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Pressure drop in woven-spacer-filled channels for reverse electrodialysis: CFD prediction and experimental validation

2015

Reverse electrodialysis (RED) is a promising technology for electric power generation by the chemical potential difference of two salt solutions within a stack equipped by selective ionexchange membranes (salinity gradient energy). Mechanical energy is required for pumping the feed solutions, which can reduce dramatically the net power output. In this work Computational Fluid Dynamics (CFD) simulations of spacer-filled channels for RED were carried out in parallel with an experimental campaign focused on the collection of data for model validation.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciWoven spacer Pressure drop Reverse Electrodialysis; CFDWoven spacer Pressure drop Reverse ElectrodialysiCFDSettore ING-IND/19 - Impianti Nucleari
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Reverse Electrodialysis: Applications to Different Case Studies

2018

Salinity gradient is a non-conventional renewable energy form which is widely available worldwide. Reverse Electrodialysis is a promising and innovative technology able to convert directly this chemical renewable energy into electricity. This paper presents a number of different scenarios where salinity gradients are naturally available or they result from industrial/urban activities. A sophisticated model accounting for all the main phenomena (including all the detrimental ones) occurring within a Reverse Electrodialysis unit has been purposely developed. The model is used to calculate how much electric energy can be harvested from the above-mentioned salinity gradients.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicibusiness.industryEnvironmental engineering02 engineering and technology010501 environmental sciences021001 nanoscience & nanotechnology01 natural sciencesRenewable energySalinityElectric energyReversed electrodialysisMembrane Open-loop RED Reverse Electrodialysis Salinity Gradient PowerEnvironmental scienceElectricity0210 nano-technologybusiness0105 earth and related environmental sciences
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CFD study on the influence of water transpiration on flow and mass transfer in channels with bipolar membranes

2018

The future energetic supply based on the massive use of renewable sources poses issues linked to fluctuations of power produced and consumed, thus requiring the use of energy storage systems.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimicielectrodialysiBipolar membranemass transportCFDreverse electrodialysiSettore ING-IND/19 - Impianti Nucleari
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Mechanical-fluid dynamics coupled model for profiled Ion Exchange Membranes design

2018

In this work, we developed an advanced model useful for the design of profiled IEMs, based on the coupled simulation of local mechanical deformations and of fluid dynamics and associated mass transport phenomena within deformed channels

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimicielectrodialysideflectionCFDSettore ICAR/08 - Scienza Delle Costruzionireverse electrodialysiSettore ING-IND/19 - Impianti NucleariIon exchange membrane
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Integrated modelling of membrane deformation, fluid dynamics and mass transfer in electromembrane processes

In recent years, water and energy supply issues have drawn the attention of the scientific community to electromembrane processes. Electrodialysis (ED) and Reverse Electrodialysis (RED) are two of the most attractive electromembrane technologies for water desalination and electric energy production from salinity gradients, respectively. In order to gain an important place in the industrial market, technological challenges on various aspects are involved in the optimization of these processes. In this context, profiled membranes exhibit interesting performance. However, the mechanical behavior of the membranes and its interaction with fluid dynamics has been poorly investigated so far. In me…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicielectrodialysifluid-structure interactionmembrane deflectionCFDreverse electrodialysiSettore ING-IND/19 - Impianti NucleariIon exchange membrane
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Experimental analysis of a continuously operated reverse electrodialysis unit fed with wastewaters

2017

Reverse Electrodialysis (RED) is one of the most promising technologies to convert salinity gradient chemical energy into electricity. RED units are traditionally operated with natural streams as river water and seawater thereby limiting the spread of the technology in sites far from coastal areas. Aim of the present work is that of exploring and expanding feed possibilities for RED systems by employing waste streams. Thus, an experimental study was performed by testing, for the first time, a Reverse Electrodialysis (RED) unit fed with a high salinity wastewater originated in a fish canning factory, and a low salinity wastewater from a sewage treatment plant. Uninterrupted, long duration ex…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicilcsh:Computer engineering. Computer hardwareReverse Electrodialysis Salinity gradient power foulinglcsh:TP155-156lcsh:TK7885-7895lcsh:Chemical engineeringChemical Engineering Transactions
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