Search results for "Salinity Gradient Power"
showing 10 items of 46 documents
Reverse electrodialysis with saline waters and concentrated brines: A laboratory investigation towards technology scale-up
2015
Abstract The use of concentrated brines and brackish water as feed solutions in reverse electrodialysis represents a valuable alternative to the use of river/sea water, allowing the enhancement of power output through the increase of driving force and reduction of internal stack resistance. Apart from a number of theoretical works, very few experimental investigations have been performed so far to explore this possibility. In the present work, two RED units of different size were tested using artificial saline solutions. The effects of feed concentration, temperature and flowrate on process performance parameters were analysed, adopting two different sets of membranes. These experiments all…
CFD PREDICTION OF SCALAR TRANPORT IN THIN CHANNELS FOR REVERSE ELECTRODIALYSIS
2014
Reverse ElectroDialysis (RED) is a very promising technology allowing the electrochemical potential difference of a salinity gradient to be directly converted into electric energy. Fluid dynamics optimization of the thin channels to be devoted for the RED process is still an open problem. The present preliminary work focuses on the Computational Fluid Dynamics (CFD) simulation of the flow and concentration fields in these channels. In particular three different configurations were investigated: a channel unprovided with a spacer and two different spacer (made of either overlapped filaments or woven filaments) filled channels. Two passive scalars were transported along with the water in orde…
Performance of the first reverse electrodialysis pilot plant for power production from saline waters and concentrated brines
2016
Abstract This work reports experimental data collected for the first time on a full-scale RED pilot plant operated with natural streams in a real environment. The plant – located in the South of Italy – represents the final accomplishment of the REAPower project ( www.reapower.eu ). A RED unit equipped with almost 50 m2 of IEMs (125 cell pairs, 44x44 cm2) was tested, using both artificial and natural feed solutions, these latter corresponding to brackish water (≈0.03 M NaClequivalent) and saturated brine (4–5 M NaClequivalent). A power output up to around 40 W (i.e. 1.6 W/m2 of cell pair) was reached using natural solutions, while an increase of 60% was observed when testing the system with…
Towards 1 kW power production in a reverse electrodialysis pilot plant with saline waters and concentrated brines
2017
Abstract Reverse electrodialysis (RED) is a promising technology to extract energy from salinity gradients, especially in the areas where concentrated brine and saline waters are available as feed streams. A first pilot-scale plant was recently built in Trapani (Italy), and tested with real brackish water and brine from saltworks. The present work focuses on the scale-up of the pilot plant, reaching more than 400 m 2 of total membrane area installed and representing the largest operating RED plant so far reported in the literature. With a nominal power capacity of 1 kW, the pilot plant reached almost 700 W of power capacity using artificial brine and brackish water, while a 50% decrease in …
CFD analysis of concentration polarization phenomena in spacer-filled channels for Reverse Electro-Dialysis
2012
In this work, carried out within the EU-FP7 funded REAPower project, CFD simulations were carried out in order to study the fluid flow behaviour and mass transport phenomena within spacer-filled channels.
Potential applications of Salinity Gradient Power-Heat Engines for recovering low-temperature waste heat in cogeneration plants
2021
Abstract Salinity Gradient Power-Heat Engine is an innovative technology able to convert very low-temperature heat into electricity. Energy and economic benefits could be achieved by integrating this technology into cogeneration plants, where the exploitation of waste heat available during the operation could increase the revenues arising from “High-Efficiency” labels. For the first time, this paper proposes two potential applications in this field, and three illustrative case studies are purposely investigated. In the first case study, a salinity gradient-heat engine converts the waste heat available from a cogeneration plant serving an industrial process. In the second case study, a salin…
Reverse Electrodialysis with seawater and concentrated brine: a comprehensive process modelling
2012
A methodology for assessing the impact of salinity gradient power generation in urban contexts
2018
Abstract The paper proposes a methodology to assess the potential impact of salinity gradient power technology in urban contexts. The idea to employ such energy source in urban contexts derives from the observation that, among the energy districts outputs, low-salinity treated wastewater can be used to produce electricity if a suitable source of high salinity feed (seawater of a salt-works) is also available. The methodology uses the HOMER software for assessing the district’s electric energy production, consumption and exchange with the main grid. Then, starting from the total gross surface and the number of inhabitants of the district, some possible realistic scenarios characterized by di…
REVERSE ELECTRODIALYSIS HEAT ENGINE: Low-grade Waste Heat into Electricity
Our society is undergoing a progressive change about the life style and habits. The world population is continuously increasing with 7.6 billion of human beings in 2018, resulting in an increasingly demand of resources in terms of food, water and energy. The exploitation of the planet resources since the first Industrial Revolution, results today in an unsustainable condition, which requires fundamental changes. In particular, in the energy sector the adoption of fossil fuels as the main energy source for human beings’ activities resulted in a strong impact on our planet, leading to climate changes and environmental pollution. Nowadays these aspects have induced society to a substantial cha…
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…