Search results for " Waste heat"
showing 10 items of 15 documents
Electrical power production from low-grade waste heat using a thermally regenerative ethylenediamine battery
2017
Abstract Thermally regenerative ammonia-based batteries (TRABs) have been developed to harvest low-grade waste heat as electricity. To improve the power production and anodic coulombic efficiency, the use of ethylenediamine as an alternative ligand to ammonia was explored here. The power density of the ethylenediamine-based battery (TRENB) was 85 ± 3 W m−2-electrode area with 2 M ethylenediamine, and 119 ± 4 W m−2 with 3 M ethylenediamine. This power density was 68% higher than that of TRAB. The energy density was 478 Wh m−3-anolyte, which was ∼50% higher than that produced by TRAB. The anodic coulombic efficiency of the TRENB was 77 ± 2%, which was more than twice that obtained using ammon…
On the regeneration of thermally regenerative ammonia batteries
2018
In the past few years, thermally regenerative ammonia battery (TRAB) has been proposed as an effective tool to recover waste heat at temperatures below 130 °C. Most of the literature available is devoted to the power production step, with less attention being given to the regeneration step (e.g. the removal of ammonia from the anolyte). In this paper, the TRAB is analyzed with particular attention to the regeneration step and to the study of various generation of energy-regeneration cycles. It was shown that approximately 90 °C is necessary for the regeneration step due to the fact that ammonia is present in the anolyte mainly as a complex. Various cycles were performed with success, demons…
CLOSING THE LOOP: STUDY OF INTEGRATED CYCLES WITH NATURAL AND ARTIFICIAL SOLUTIONS FOR THE PRODUCTION OF ENERGY, MINERALS AND FRESH WATER
Societal and economic aspects of a novel circular system for the valorisation of desalination brine and waste heat from a power plant
2022
Direct disposal of concentrate brines produced in industrial plants can have a relevant impact to environmental systems. For this reason, brine treatment and valorisation could help to avoid disposal and produce marketable salts, thus representing a possible economic benefit. With this aim, a novel process, where advanced separation technologies are combined with waste heat recovery, is proposed within the EU-funded WATER MINING project. The Case Study presented in this work concerns the power plant in Lampedusa island, where waste heat and desalination brine are available to implement the process via a pilot plant to be installed for alternative thermal treatment of the brine. The aim is t…
Evaluation of the Economic and Environmental Performance of Low-Temperature Heat to Power Conversion using a Reverse Electrodialysis – Multi-Effect D…
2019
In the examined heat engine, reverse electrodialysis (RED) is used to generate electricity from the salinity difference between two artificial solutions. The salinity gradient is restored through a multi-effect distillation system (MED) powered by low-temperature waste heat at 100 °C. The current work presents the first comprehensive economic and environmental analysis of this advanced concept, when varying the number of MED effects, the system sizing, the salt of the solutions, and other key parameters. The levelized cost of electricity (LCOE) has been calculated, showing that competitive solutions can be reached only when the system is at least medium to large scale. The lowest LCOE, at a…
Industrial waste heat: Estimation of the technically available resource in the EU per industrial sector, temperature level and country
2018
Abstract Industrial waste heat is examined in EU countries, focusing on the amount that can be recovered and exploited, referred to as technical potential of waste heat. An alternative methodology is proposed here, which is based on waste heat fractions derived from a detailed study of the UK industry from the period 2000–2003. These fractions express the part of heat consumption that is wasted and is possible to be recovered. The waste heat fractions have been calculated in this work for each main industrial sector and temperature level. The methodology initially includes the adjustment of waste heat fractions from each industrial sector from the UK industry to the conditions of the differ…
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…
Membrane distillation: solar and waste heat driven demonstration plants for desalination
2011
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…
Water-organic systems in closed-loop reverse electrodialysis for lower regeneration requirements
2016
Salinity Gradient Power (SGP) is an emerging opportunity to produce sustainable energy. Among the different SGP technologies, Reverse ElectroDialysis (RED) looks very promising. In a RED system the salinity gradient between two different solutions is used to directly produce electricity. Closed-loop RED is an innovative process, combining a RED unit with a regeneration system. If low grade waste-heat is used for the regeneration stage, in which the initial concentrations of the solutions exiting the RED unit are restored, the closed-loop can be seen as a RED-heat-engine able to convert thermal energy into electricity. The aim of this work is to perform a preliminary analysis of a regenerati…