Search results for "WASTE"
showing 10 items of 2580 documents
Thermoeconomic optimization of a renewable polygeneration system serving a small isolated community
2015
During the last years, special attention has been paid to renewable polygeneration technologies, able of simultaneously producing thermal, cooling, electrical energy and desalinated water from seawater. This paper focuses on an innovative polygeneration system driven by renewable energy sources, including the following technologies: hybrid photovoltaic/thermal collectors, concentrating parabolic trough (CPVT), a biomass heater, a single-stage absorption chiller and a multiple-effect distillation desalination system. The system is designed to cover the base load of an isolated small community. In previous papers, the dynamic simulation model about plant operation is discussed. In this paper,…
Life cycle energy and environmental impacts of a solid oxide fuel cell micro-CHP system for residential application
2019
Abstract Fuel cells are considered one of the key technologies to reach the ambitious European goal of a low carbon economy, by reducing CO2 emissions and limiting the production of other pollutants. The manuscript presents an assessment of the life cycle energy and environmental performances of a solid oxide fuel cell system for household applications using primary data from the manufacturing phase and experimental data for the start-up and operation phases. The Life Cycle Assessment methodology is applied, based on a functional unit of 1 MJ of exergy and includes the life cycle steps from the raw materials extraction to the maintenance. The results show a particular relevance of the opera…
Exergy analysis and thermoeconomic cost accounting of a Combined Heat and Power steam cycle integrated with a Multi Effect Distillation-Thermal Vapou…
2017
Abstract In this paper an exergy analysis and thermoeconomic cost accounting of a Combined Heat and Power steam cycle integrated with Multi Effect Distillation-Thermal Vapour Compression plant is performed; the goal of the study is to show how these methodologies provide a rational criterion to allocate production costs on electricity and freshwater in such a dual purpose system. After a brief overview on the methodology and a description of reference plant, exergy analysis is carried out to calculate exergy flows and exergy efficiencies at component level. A detailed description of the adopted thermoeconomic model is given. In a first scenario, cost accounting is performed assuming that th…
A life cycle assessment of tri-generation from biomass waste: The experience of the “agro-combined” of Thibar
2020
Abstract The paper presents a life cycle assessment of energy produced by biogas obtained by biomass waste and fuelled in a tri-generation pilot plant located in Tunisia. The results, referred to 1 MJ of exergy, showed that the plant construction causes 76% of primary energy consumption and gives a contribution higher than 90% on resource depletion and ionizing radiation, and of 50% on ozone depletion. Operation causes 66% of the impact on human toxicity—cancer effects and more than 90% of the other impacts, except for ecotoxicity of freshwater mainly caused during the end of life. The study is one of the first applications of environmental analysis to tri-generation from waste in developin…
Reverse electrodialysis heat engine with multi-effect distillation: Exergy analysis and perspectives
2019
Abstract The increasing worldwide energy demand is rising the interest on alternative power production technologies based on renewable and emission-free energy sources. In this regard, the closed-loop reverse electrodialysis heat engine is a promising technology with the potential to convert low-grade heat into electric power. The reverse electrodialysis technology has been under investigation in the last years to explore the real potentials for energy generation from natural and artificial solutions, and recent works have been addressing also the potential of its coupling with regeneration strategies, looking at medium and large energy supply purposes. In this work, for the first time, a c…
Performance Analysis of a RED-MED Salinity Gradient Heat Engine
2018
A performance analysis of a salinity gradient heat engine (SGP-HE) is presented for the conversion of low temperature heat into power via a closed-loop Reverse Electrodialysis (RED) coupled with Multi-Effect Distillation (MED). Mathematical models for the RED and MED systems have been purposely developed in order to investigate the performance of both processes and have been then coupled to analyze the efficiency of the overall integrated system. The influence of the main operating conditions (i.e., solutions concentration and velocity) has been quantified, looking at the power density and conversion efficiency of the RED unit, MED Specific Thermal Consumption (STC) and at the overall syste…
Concepts for medium-high to high temperature thermoelectric heat-to-electricity conversion: a review of selected materials and basic considerations o…
2015
Within the last decade, novel materials concepts and nanotechnology have resulted in a great increase of the conversion efficiency of thermoelectric materials. Despite this, a mass market for thermoelectric heat-to-electricity conversion is yet to be opened up. One reason for this is that the transfer of the lab records into fabrication techniques which enable thermoelectric generator modules is very challenging. By closing the gap between record lab values and modules, broad industrial applications may become feasible. In this review, we compare three classes of materials, all designed for medium-high to high temperature applications in the field of waste heat recovery: skutterudites, half…
Dimensions of household food waste focused on family and consumers
2020
Food waste produced in homes represents the largest fraction of food waste generated along the food chain. Therefore, adequate prevention measures based on the quantitative and qualitative dimensions of the problem need to be put in place to reduce waste. The objective of the review was to identify areas of interest in relation to the food waste in households, considering the family unit as a whole as well as individual family members. Quantifying the problem is an important aspect in order to know its scope and dimension, but prevention also involves knowing the causes in a home. This is a complex issue, which, on a family level, is related to socioeconomic status, educational level, compo…
Water Depollution by Advanced Oxidation Technologies
2020
This chapter deals with water treatments by advanced oxidation processes (AOPs) based on chemical and photochemical reactions. The most used processes are described, and for each of them, the main reaction mechanisms, principles, advantages, drawbacks, performances and formation of by-products, coupled with technologies and their applications to waters and wastewater depollution, have been analysed, supporting the main results of studies published in the pertinent literature.
AnMBR, reclaimed water and fertigation: Two case studies in Italy and Spain to assess economic and technological feasibility and CO2 emissions within…
2020
[EN] The use of anaerobic membrane bioreactor (AnMBR) technology on urban wastewater can help to alleviate droughts, by reusing the water and nutrients embedded in the effluent in agriculture (fertigation) in line with Circular Economy principles. The combination of AnMBR and fertigation reduces CO2 emissions due to the organic matter valorization and the partial avoidance of mineral fertilizer requirements. However, both AnMBR and fertigation still face technological and regulatory barriers that need to be overcome. These bottlenecks were tackled within the first Innovation Deal approved by the European Commission in 2016, and gave rise to several case studies on water reuse systems. The r…