Desalination is commonly adopted nowadays to overcome the freshwater scarcity in some areas of the world if brackish water or salt water is available. Different kinds of technologies have been proposed in the last century. In this paper, the state of the mainstream solutions is reported, showing the current commercial technologies like reverse osmosis (RO), Multi-Stages Flash desalination (MSF) and Multi-Effect Distillation (MED), and the new frontiers of the research with the aim of exploiting renewable sources such as wind, solar and biomass energy. In these cases, seawater treatment plants are the same as traditional ones, with the only difference being that they use a renewable energy source. Thus, classifications are firstly introduced, considering the working principles, the main energy input required for the treatment, and the potential for coupling with renewable energy sources. Each technology is described in detail, showing how the process works and reporting some data on the state of development. Finally, a statistical analysis is given concerning the spread of the various technologies across the world and which of them are most exploited. In this section, an important energy and exergy analysis is also addressed to quantify energy losses.
The proposal of new technologies capable of producing electrical energy from renewable sources has driven research into seas and oceans. Research finds this field very promising in the future of renewable energies, especially in areas where there are specific climatic and morphological characteristics to exploit large amounts of energy from the sea. In general, this kind of energy is referred to as six energy resources: waves, tidal range, tidal current, ocean current, ocean thermal energy conversion, and saline gradient. This review has the aim to list several wave-energy converter power plants and to analyze their years of operation. In this way, a focus is created to understand how many wave-energy converter plants work on average and whether it is indeed an established technology.
In order to limit the anthropic emissions of CO2, research is currently investigating new materials for the building sector. The main purpose is the reduction in the embodied energy consumption, especially in the residential sector, and consequently the limitation of the direct and indirect utilization of fossil fuels, for the indoor heating, cooling, and ventilation services. Indeed, the residential sector is affected by a high energy demand, thus the choice of improved materials is fundamental to improve the sustainability. All phases: construction, building life, and dismantling are impacting in terms of resource and energy consumption, both associated with the emissions of pollutants in the atmosphere. The aim of this experimental research is to study the thermal insulation and the acoustic absorption of a material composed by natural lime, water, and shives from sativa hemp, a variety of hemp usable for industrial applications. In order to assess the main characteristics of this material, some specimens have been made according to required shapes and sizes to test them in specific machines. The results obtained from the tests are compared with the values of similar lime-based materials already available on the market. The comparison shows how, in certain aspects, the lime and hemp shives materials represent a concrete alternative to conventional materials. This completely natural material would like to achieve thermal and acoustic comfort in indoor environments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.