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The sustainability assessment methodology has to be demonstrated in order to become the tool in the engineering practice. This chapter is devoted to the attempt to evaluate the sustainability of energy systems and show how it can be used in the everyday engineering practice. Obviously, this type of approach has its limitation due to the lack of data for the serious consideration of the system. But it should be anticipated that these excises might serve as guidance for eventual future applications. Also, it should be emphasised that this type of methodology will become an useful tool only if it proves to be justified in the engineering practice.

Abstract This paper presents a new methodology for impact assessment—SIAM (Spatial Impact Assessment Methodology)—which is based on the assumption that the importance of environmental impacts is dependent, among other things, on the spatial distribution of the effects and of the affected environment. The information generated by the use of Geographical Information Systems (GIS) in impact identification and prediction stages of Environmental Impact Assessment (EIA) is used in the assessment of impact significance by the computation of a set of impact indices. For each environmental component (e.g., air pollution, water resources, biological resources), impact indices are calculated based on the spatial distribution of impacts. A case study of impact evaluation of a proposed highway in Central Portugal illustrates the application of the methodology and shows its capabilities to be adapted to the particular characteristics of a given EIA problem.

Sustainability assessment and rating systems are intended to foster more sustainable design, construction, operation, maintenance and disassembly/deconstruction promoting and making possible a better integration of environment, societal, and cost concerns with other traditional decision criteria. The use of improved and building technologies can contribute considerably to better environmental cycle and then to the sustainability of the constructions. It is widely recognised in the of Building Sustainability Assessment that Life Cycle Assessment (LCA) is a much preferable method for evaluating the environmental pressure caused by materials, Building assemblies and the whole life-cycle of a building. Nevertheless, LCA tools are not extensively used in building design and most of building sustainability assessment and systems are not comprehensive or consistently LCA-based. Reasons for this failure above all related to the huge variety and amount of material flows and processes of building’s Lifecycle and to the complexity of the stages of a LCA. This paper will present the difficulties and possible solutions to integrate more accurate environmental methods in rating systems. In this context, the paper will also present the work that is being carried out in the development of the Portuguese Building Sustainability Assessment system (SBTool PT)

In the context of globalisation, is a country’s level of development an obstacle to its environmental performance? The main objective of this research is to identify the role played in the environmental performance of countries with different levels of development, globalisation, and environmental regulation, by the three dimensions and two new measures of globalisation, de jure and de facto. This analysis was accomplished by assessing the environmental curve which relates economic growth to environmental degradation, known as the environmental Kuznets curve, for a sample of 32 developed and 26 developing economies from 1995 to 2017. It was found that developed countries produced an inverted U-shaped curve and that globalisation had a mostly beneficial effect on the environment. In contrast, developing economies produced a U-shaped curve and globalisation was generally harmful. Globalisation caused reductions of 0.88% and 0.85% in the environmental degradation of developed countries, and increases of 0.20% and 0.52% in developing ones. Political globalisation produced different effects for each measure in developed countries and had no effect in developing countries. Economic globalisation suggests the relocation of polluting industries from developed to developing countries. As there is currently very little literature on the new measures of globalisation, this study provides fresh insights for policymakers devising appropriate measures to achieve sustainability in both developed and developing countries.

Abstract The need to generate thermal and electrical energy, global warming caused by increased emissions of greenhouse gases, rising fossil fuel prices and demand for energy independence, have created a new industry focused on energy production through the use of renewable sources. Among the different options, biomass is the third most important source for obtaining electricity, and is the main source for the production of thermal energy. However, problems related to the low density of the different types of biomass, and the difficulty of transportation and storage, have led to the need to find solid fuels with higher density and greater hardness, known as pellets and briquettes. This paper seeks to develop an analysis of the current situation of the production of pellets, mainly with mixed biomass types, and the possible uses they have, with the main emphasis on the review of different combustion processes.

Abstract Molten salts are a very relevant member of industrial fluids for high temperature applications, such as catalytic medium for coal gasification, molten salt oxidation of wastes, heat transfer fluids or latent, sensible heat storage and solar (CSP) or nuclear power station operations. Available data on thermophysical properties, applications and a discussion of the state of the art for molten alkali carbonates and its mixtures like pure Li2CO3, Na2CO3 and K2CO3, mixtures of Li2CO3-Na2CO3, Li2CO3-K2CO3 (binary eutectics) and Li2CO3-Na2CO3-K2CO3 (ternary eutectic) and nanofluids based in these carbonate melts are presented. These melts are especially suitable for application at higher temperature regimes, like those involving high temperature energy storage, coolants or molten salts oxidations of wastes and therefore the accurate knowledge of their most important thermophysical properties is essential for efficient energy transfer and storage, because of their impact on energy efficiency, namely in energy savings and decrease of carbon footprint. From the analysis performed it can be concluded that the scatter of data found for molten alkali carbonates, added to present and future applications, still justifies further studies on these systems, to support their application as alternative engineering fluids. Additionally, some comments on how to improve present situation of methods and measurements are made, especially in the area of thermal conductivity.

A methodology for the sizing of domestic hot water heating and storage systems is defined, by assuming an extreme operating condition cycle composed of only two parts, a water consumption period and a system repositioning period. In both parts to respond to the extreme hot water demanding conditions, the heating is always on. The subsequent exergy analysis of this domestic hot water production system compares the irreversibility and the exergy efficiency of the water storage and the tankless situation. To carry out such analysis, some basic assumptions were made: a constant temperature heat source, a short duration operating cycle and a constant thermal energy supply. Under these circumstances it is shown that the hot water storage system leads to lower exergy losses while the tankless system is more exergy efficient, but requiring a higher instantaneous thermal power input. The use of the joule effect electricity, as the system heat source, be it a water storage one or a tankless one, maximizes the system irreversibility losses and minimizes the system exergy efficiency. The tankless system, with the joule effect electricity heat source is the worst situation.

The intensive agricultural practices are increasing the demand for chemical fertilizers, being currently produced from a non-environmental friendly way. Besides the environmental impacts, the nutrient uptake efficiency by the crops is very low, representing huge losses into the fields. Therefore, it is crucial to study alternatives for the current chemical fertilizers, which simultaneous improve nutrient efficiency and minimize environmental impacts. A sustainable solution is to recover nutrients from wastewater streams with microalgal cultures and the biomass conversion into bio-char for soil amendment. Wastewaters are loaded with nitrogen and phosphorus and can be used as culture medium for microalgae. Thus, nutrients can be recycled, reducing the requirement of chemical fertilizers. This paper aims to review nutrient recovery from wastewater using microalgae and the biomass conversion into bio-char. This process promotes nutrient recycling and the bio-char (when added to soil) improves the nutrient uptake efficiency by crops.