Search results for "Regeneration Unit"

Novel solutions for closed-loop Reverse Electrodialysis: thermodynamic characterisation and perspective analysis

2019

Abstract Closed-loop Reverse Electrodialysis is a novel technology to directly convert low-grade heat into electricity. It consists of a reverse electrodialysis (RED) unit where electricity is produced exploiting the salinity gradient between two salt-water solutions, coupled with a regeneration unit where waste-heat is used to treat the solutions exiting from the RED unit and restore their initial composition. One of the most important advantages of closed-loop systems compared to the open systems is the possibility to select ad-hoc salt solutions to achieve high efficiencies. Therefore, the properties of the salt solutions are essential to assess the performance of the energy generation a…

Thermodynamic characterisation of novel solutions for closed-loop reverse electrodialysis

2018

Closed-loop reverse electrodialysis is a novel technology to convert low-grade heat directly into electricity. It consists of a reverse electrodialysis unit coupled with a regeneration unit in which the waste-heat is used to restore the initial conditions of the two solutions. One of the most impor- tant advantages of closed-loop system is the possibility to select an ad-hoc salt solution to obtain high efficiency. In this regard, it is important to assess how the salt solution properties affect the performance of the energy generation and solution regeneration processes. The aim of this study is to analyse the effect of thermodynamic properties of non-conventional salt solutions within a R…

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…

Thermolytic reverse electrodialysis heat engine: model development, integration and performance analysis

2019

Abstract Salinity gradient heat engines represent an innovative and promising way to convert low-grade heat into electricity by employing salinity gradient technology in a closed-loop configuration. Among the aqueous solutions which can be used as working fluid, ammonium bicarbonate-water solutions appear very promising due to their capability to decompose at low temperature. In this work, an experimentally validated model for a reverse electrodialysis heat engine fed with ammonium bicarbonate-water solutions was developed. The model consists of two validated sub-models purposely integrated, one for the reverse electrodialysis unit and the other for the stripping/absorption regeneration uni…

Resource, environmental and economic considerations in the development of a Reverse Electrodialysis Heat Engine

The RED Heat Engine operates as a closed-loop RED system, where limited amounts of artificial saline solutions are used as working fluids. The solutions exiting from the RED unit are regenerated by means of a separation step, which uses low-temperature heat as its energy source. Essentially the system converts low-grade heat to electricity. There are two main alternative regeneration strategies: (i) extract solvent from the high salinity solution and move it to the low salinity solution or (ii) extract salt from the low salinity solution and move it to the high salinity solution. In this thesis are considered the Multi-effect distillation (MED) and the Membrane Distillation (MD) under the s…