Search results for "Note"

showing 10 items of 10709 documents

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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CFD analysis of the fluid flow behavior in a reverse electrodialysis stack

2012

Salinity Gradient Power by Reverse Electrodialysis (SGP-RE) technology allows the production of electricity from the different chemical potentials of two differently concentrated salty solutions flowing in alternate channels suitably separated by selective ion exchange membranes. In SGP-RE, as well as in conventional ElectroDialysis (ED) technology, the process performance dramatically depends on the stack geometry and the internal fluid dynamics conditions: optimizing the system geometry in order to guarantee lower pressure drops (DP) and uniform flow rates distribution within the channels is a topic of primary importance. Although literature studies on Computational Fluid Dynamics (CFD) a…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciSpacer-filled channelSettore ING-IND/25 - Impianti ChimiciOcean Engineering02 engineering and technology010501 environmental sciencesComputational fluid dynamics01 natural sciencesStack (abstract data type)Reversed electrodialysisFluid dynamicsOsmotic powerStack designPressure dropSettore ING-IND/19 - Impianti NucleariSimulation0105 earth and related environmental sciencesWater Science and Technologybusiness.industryChemistryModelingProcess (computing)MechanicsElectrodialysis021001 nanoscience & nanotechnologyPollution6. Clean waterCFD; Modeling; Stack design; Pressure drops; Spacer-filled channelSettore ING-IND/06 - FluidodinamicaPotential flowCFD0210 nano-technologybusinessDesalination and Water Treatment
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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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Diffusion dialysis for the treatment of H2SO4-CuSO4 solutions from electroplating plants: Ions membrane transport characterization and modelling

2021

Diffusion dialysis (DD) is proposed to separate and recover mineral acids and transition metals from electroplating industry process waters promoting a circular approach of resources recovery. In this work, a DD module with two anionic membranes (Fumasep FAD and Neosepta AFN) are used for the separation of H2SO4 from Cu2+ containing solutions. The membrane performances with sole H2SO4 solutions (0.2–2 M) and sole CuSO4 solutions (0.8–1.1 M Cu2+) and with mixtures of H2SO4 (0.6 M) and CuSO4 (0.2–1.1 M Cu2+) as feed are studied. H2SO4 recovery efficiency decreases as the concentration of acid increases. For H2SO4 solutions, the water drag flux from the retentate to the diffusate prevails agai…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciWork (thermodynamics)Brine valorizationCircular economyEconomia circularDiffusionAigües residuals -- DepuracióAnalytical chemistryCopper electroplatingSulphuric acid recoveryFiltration and Separation02 engineering and technologyGalvanoplàstiaCopper electroplating Sulphuric acid recovery Brine valorization Circular economy Industrial wastewater treatment Diffusion dialysisAnalytical ChemistryIndustrial wastewater treatment:Enginyeria química [Àrees temàtiques de la UPC]020401 chemical engineering0204 chemical engineeringElectroplatingChemistryIndustrial wastewater treatmentMembrane transport021001 nanoscience & nanotechnologyElectroplatingMembraneSewage -- PurificationDiffusion dialysis0210 nano-technologyDialysis (biochemistry)Flux (metabolism)
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Water desalination by capacitive electrodialysis: Experiments and modelling

2020

Abstract Electrodialysis-related technologies keep spreading in multiple fields, among which water desalination still plays a major role. A new technology that has not yet been thoroughly investigated is capacitive electrodialysis (CED), which couples the standard ED with capacitive electrodes. CED has a number of advantages such as removal of toxic products and system simplification. Little mention is made of this technology in the literature and, to the best of our knowledge, no modelling works have ever been presented. In this work, the CED process has been studied through experiments and modelling. A CED model is presented for the first time. With a simple calibration based on macroscop…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciWork (thermodynamics)Computer scienceGeneral Chemical EngineeringCapacitive sensing02 engineering and technologyCapacitive electrodes020401 chemical engineeringCalibrationGeneral Materials ScienceElectromembrane proce0204 chemical engineeringProcess engineeringWater desalinationIon exchange membraneWater Science and TechnologyDesalinationbusiness.industryMechanical EngineeringProcess (computing)Experimental dataGeneral ChemistryCarbon electrodeElectrodialysis021001 nanoscience & nanotechnology6. Clean water0210 nano-technologybusinessDynamic simulationDesalination
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A Novel Ionic Exchange Membrane Crystallizer to Recover Magnesium Hydroxide from Seawater and Industrial Brines

2020

A novel technology, the ion exchange membrane crystallizer (CrIEM), that combines reactive and membrane crystallization, was investigated in order to recover high purity magnesium hydroxide from multi-component artificial and natural solutions. In particular, in a CrIEM reactor, the presence of an anion exchange membrane (AEM), which separates two-compartment containing a saline solution and an alkaline solution, allows the passage of hydroxyl ions from the alkaline to the saline solution compartment, where crystallization of magnesium hydroxide occurs, yet avoiding a direct mixing between the solutions feeding the reactor. This enables the use of low-cost reactants (e.g., Ca(OH)2) without …

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicibrine valorisationInorganic chemistryIonic bondingchemistry.chemical_elementFiltration and Separation02 engineering and technologylcsh:Chemical technologyArticlelaw.inventionmembrane crystallizer020401 chemical engineeringlawChemical Engineering (miscellaneous)lcsh:TP1-1185critical raw materiallcsh:Chemical engineering0204 chemical engineeringCrystallizationwastewaterIon exchangeChemistryMagnesiumProcess Chemistry and Technologylcsh:TP155-156bitternContamination021001 nanoscience & nanotechnology6. Clean waterMembraneBrineSeawater0210 nano-technologyMembranes
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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 simulations of early- to fully-turbulent conditions in unbaffled and baffled vessels stirred by a Rushton turbine

2021

Abstract Laboratory scale unbaffled tanks provided with a top cover and a baffled tank both stirred by a Rushton turbine were simulated by carrying out RANS simulations. Three different turbulence models were adopted (k- ω SST, k- e and the SSG Reynolds stress model) to predict the flow field and the relevant performance parameters (power and pumping numbers) of the tank operated from early to fully turbulent conditions. CFD results were compared with literature experimental data and DNS simulation results to validate and properly compare the models. In the range of Reynolds numbers investigated, results showed that, for the unbaffled tank, the SSG model based on Reynolds stresses is a bett…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicibusiness.industryTurbulenceGeneral Chemical EngineeringSettore ING-IND/25 - Impianti ChimiciReynolds number02 engineering and technologyGeneral ChemistryReynolds stressMechanicsComputational fluid dynamicsLaboratory scale021001 nanoscience & nanotechnologyFlow fieldRushton turbinesymbols.namesake020401 chemical engineeringCFD SSG Stirred tank Turbulence model Unbaffled vesselsymbols0204 chemical engineering0210 nano-technologybusinessReynolds-averaged Navier–Stokes equationsSettore ING-IND/19 - Impianti NucleariMathematics
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Electrodialysis Applications in Wastewater Treatment for Environmental Protection and Resources Recovery: A Systematic Review on Progress and Perspec…

2020

This paper presents a comprehensive review of studies on electrodialysis (ED) applications in wastewater treatment, outlining the current status and the future prospect. ED is a membrane process of separation under the action of an electric field, where ions are selectively transported across ion-exchange membranes. ED of both conventional or unconventional fashion has been tested to treat several waste or spent aqueous solutions, including effluents from various industrial processes, municipal wastewater or salt water treatment plants, and animal farms. Properties such as selectivity, high separation efficiency, and chemical-free treatment make ED methods adequate for desalination and othe…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicireverse electrodialysisbrine valorisationBipolar membrane electrodialysis Brine valorisation Electro-membrane process Electrodeionisation Electrodialysis metathesis Electrodialysis reversal Monovalent selective membranes Reverse electrodialysis Selectrodialysis Water reuseFiltration and Separation02 engineering and technologyReview010501 environmental scienceswater reuselcsh:Chemical technologyelectrodialysis metathesis01 natural sciences7. Clean energyDesalination12. Responsible consumptionselectrodialysiselectrodeionisationReversed electrodialysiselectrodialysis reversalChemical Engineering (miscellaneous)lcsh:TP1-1185lcsh:Chemical engineeringEffluentelectro-membrane process0105 earth and related environmental sciencesbipolar membrane electrodialysisElectrodialysis reversalWaste managementProcess Chemistry and Technologymonovalent selective membraneslcsh:TP155-156Electrodialysis021001 nanoscience & nanotechnology6. Clean waterWastewater13. Climate actionEnvironmental scienceSewage treatmentValorisation0210 nano-technologyMembranes
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IL DIRITTO ALLO STUDIO NELLE LEGISLAZIONI REGIONALI.RIFLESSIONI A PARTIRE DALLA LEGGE REGIONALE SICILIANA. 10 DEL 20 GIUGNO 2019

2019

Analisi dei diversi sistemi regionali di tutela del diritto allo studio, partendo dall'analisi della nuova legge regionale siciliana n. 10 del 2019. Essa appare innovativa per molteplici aspetti, sebbene dubbi possono sollevarsi per quanto concerne la concreta attuazione soprattutto dal punto di vista economico, nonchè a causa della forte centralizzazione presso la Giunta regionale delle relative funzioni amministrative. Analysis of the different regional systems of protection of the right to study, starting from the analysis of the new Sicilian regional law n. 10 of 2019. It appears to be innovative in many respects, although doubts may arise as far as verifying the concrete implementation…

Settore IUS/08 - Diritto CostituzionaleAnalysis and comparison of the different regional systems for implementing the right to study with particular reference to the new Sicilian law n. 10 of 20 June 2019 which is noted for centralizing the relevant functions in the regional government.
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