Search results for "reverse electrodialysis."
showing 10 items of 74 documents
Techno-economic evaluation of Reverse Electrodialysis process in different real environments
2018
Salinity Gradient Power is a promising renewable energy source based on the recovery of the chemical potential released from the mixing of solutions at different concentrations. Natural salinity gradients are extensively available worldwide in natural reservoirs. Reverse Electrodialysis is an innovative technology able to perform a direct conversion of the energy of mixing into electricity. Salinity gradients coming from natural resources or from human activities are worldwide available. In the present work a number of different scenarios, including natural resources (e.g. rivers, seas, lakes and salt ponds), industrial/urban wastes (e.g. brine and treated wastewaters) are analysed. The aim…
Thermal regeneration of ammonium bi-carbonate solutions for closed-loop reverse electrodialysis
2016
Reverse electrodialysis is a novel technology that exploits a salinity gradient to generate electrical energy. The salinity gradient can be available from natural waters such as seawater and river water or they can be artificially generated and used within closed-loop applications. This last option has been recently investigated leading to the development of the RED heat engine concept. In this case, the deployed salinity gradient exiting the RED unit is regenerated in a thermally-driven unit using low-temperature heat, thus being able to convert heat to power within an integrated system. Among the different regeneration alternatives, the use of thermolytic salts has been presented as a pro…
Reverse Electrodialysis with brackish water and concentrated brines: up-scaled pilot plant operating in a real environment
2015
This work focuses on the saling up of the REA Power plant through the installation of two larger RED modules
Valorization of surface-water RO brines via Assisted-Reverse Electrodialysis for minerals recovery: performance analysis and scale-up perspectives
2021
Reverse Osmosis (RO) plays a key role in seawater and brackish water desalination to fulfill the growing demand for fresh water. In recent years, RO has also been more and more adopted for the treatment and potabilization of surface waters, leading to two main problems: (i) the depletion in minerals of the product water, making it aggressive and unsuitable for drinking purposes and (ii) the production of a concentrated brine requiring proper disposal. Permeate remineralization post-treatments include pH adjustment and addition of minerals, such as bicarbonates, calcium and magnesium, which are essential for human health and required to meet drinking water guidelines. However, such solutions…
Reverse electrodialysis – Multi effect distillation heat engine fed by lithium chloride solutions
2019
Salinity Gradient Heat Engines (SG-HEs) have been proposed as a promising technology for converting low-temperature heat into electricity. The SG-HE includes two different processes: (i) a salinity gradient process where the salinity gradient between two solutions is converted into electricity and (ii) a thermal regeneration process where low-grade heat (T<100°C) is used to re-establish the original salinity gradient of the two streams. Among the proposed working solutions, aqueous solution of lithium chloride has been identified as one of the most promising thanks to its remarkable solubility and activity. In this work, a process model to study the performance of a SG-HE constituted by …
RED Heat-to-Power: conversione di calore di scarto in energia elettrica mediante elettrodialisi inversa a ciclo chiuso
2016
La produzione di energia da gradienti salini si sta affermando come una valida alternativa alle tradizionali fonti di energia rinnovabili. In particolare l’elettrodialisi inversa (RED) è di certo tra le tecnologie più promettenti per effettuare la conversione di gradienti salini in energia utile. Un recente sviluppo è l’utilizzo del processo RED a ciclo chiuso con soluzioni saline artificiali, nel quale le soluzioni in uscita dall’unità RED vengono rigenerate all’interno di un’unità di rigenerazione termica, che ripristina il gradiente salino iniziale. L’utilizzo del sistema a ciclo chiuso premette dunque di convertire calore a bassa temperatura (e.g. calore di scarto a T <70-100°C) in e…
Ion Exchange Membrane deformation and its relevance in Reverse ElectroDialysis
2017
Reverse electrodialysis (RED) is an innovative electro-membrane technology for electric energy generation from two salt solutions with different concentration. This different concentration is the driving force to a selective movement of ions from the concentrate channel to the dilute one oriented by Ion Exchange Membranes (IEMs). Typically, RED stack are made by piling alternatively cation exchange membranes and anion exchange membranes with the aid of spacers or profiles built on the membrane surface. Two electrodic compartments are placed at the two ends of the stack, where the ion flux generated is converted into an electric current able to circulate through an external load connected to…
Coupling CFD simulation with a simplified process model for reverse electrodialysis units
2017
Salinity gradient between two solutions is a renewable source of energy. Among the technologies able to exploit the salinity gradient, reverse electrodialysis (RED) is an electrochemical process for electrical power generation through direct conversion. Ion exchange membranes, piled alternately and separated by net spacers or membrane profiles, are the key elements of a RED stack. A multiplex phenomenology occurs in RED units; Ohmic and non-Ohmic (due to concentration changes) voltage losses and pressure drop are the main issues, and the membrane/channel configuration is crucial for the stack performance. In this framework, mathematical modelling can be a powerful tool for predictive purpos…
CFD analysis of mass transfer in spacer-filled channels for reverse electrodialysis
2014
Reverse electrodialysis (RE) is a promising technology for electric power generation by converting the chemical potential difference of a salinity gradient, within a stack equipped by selective ion-exchange membranes. Concentration polarization phenomena and pressure drop affect strongly the power output obtainable; therefore the channel geometry is a fundamental operating parameter for the optimization of the system. In this work, Computational Fluid Dynamic simulations were performed to predict fluid flow and mass transfer in spacer-filled channels for RE applications. A parametric analysis for different spacer geometries was carried out; in particular, woven and non woven spacers were si…
Electromembrane Processes: Experiments and Modelling
2021
This Special Issue of Membranes journal focuses on electromembrane processes and is motivated by the increasing interest of the scientific community towards their characterization by experiments and modelling for several applications [...]