• Energy Research
• other engineering and technologies close
• 12. Responsible consumption close
• 6. Clean water close
• ES close

This study focuses on formulating the most sustainable concrete by incorporating recycled concrete aggregates and other products retrieved from construction and demolition (C&D) activities. Both recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) are firstly used to fully replace the natural coarse and fine aggregates in the concrete mix design. Later, the cement rich ultrafine particles, recycled glass powder and mineral fibres recovered from construction and demolition wastes (CDW) are further incorporated at a smaller rate either as cement substituent or as supplementary additives. Remarkable properties are noticed when the RCA (4–12 mm) and RFA (0.25–4 mm) are fully used to replace the natural aggregates in a new concrete mix. The addition of recycled cement rich ultrafines (RCU), Recycled glass ultrafines (RGU) and recycled mineral fibres (RMF) into recycled concrete improves the modulus of elasticity. The final concrete, which comprises more than 75% (wt.) of recycled components/materials, is believed to be the most sustainable and green concrete mix. Mechanical properties and durability of this concrete have been studied and found to be within acceptable limits, indicating the potential of recycled aggregates and other CDW components in shaping sustainable and circular construction practices. The authors wish to acknowledge the financial support from EU Horizon 2020 Project VEEP ‘‘Cost-Effective Recycling of C&DW in High Added Value Energy Efficient Prefabricated Concrete Compo-nents for Massive Retrofitting of our Built Environment” (No.723582).

[EN]A systematic approach is developed for the conceptual optimal design of biomethane production via carbon capture. A hybrid heuristic-mathematical procedure is proposed to determine the optimal technology and operating conditions. The heuristic step consists of a literature-based screening of the available technologies. After the prescreening stage, the technologies selected are amine absorption, pressure swing adsorption (PSA), and membrane separation. The mathematical stage is composed of two steps. First, different alternatives for each technology are modeled based on first principles and rules of thumb. These models are used to select the optimal configuration for each process considered. Second, a superstructure model for biomethane production is developed integrating the pre-selected upgrading technologies to select the optimal process, as well as to determine the optimal operating conditions. Four waste sources are analyzed: cattle manure, swine manure, municipal food waste, and sludge. The results suggest that the best amine is diethanolamine (DEA), the best membrane material is the polyimide, and the suggested zeolite is 13X among the ones studied. Finally, among the three technologies, the overall results show that carbon capture using a PSA system using zeolite 13X results in lower production and investment costs, but very close to the use of membranes. The results indicate that food waste shows the lowest production cost for biomethane 0.36 €/Nm3, due to the largest organic matter content, whereas the investment costs are 67 M€, considering a biogas production rate of 0.035 kg of biomethane per kg of waste and the processing of 311 kt/yr of food waste. Credits or incentives are still needed for biomethane to be competitive with fossil natural gas. Junta de Castilla y León y USAL

Given the global energy and environmental situation, the European Union has been issuing directives with increasingly demanding requirements in term of the energy efficiency in buildings. The international competition of sustainable houses, Solar Decathlon Europe (SDE), is aligned with these European objectives. SDE houses are low energy solar buildings that must reach the near to zero energy houses’ goal. In the 2012 edition, in order to emphasize its significance, the Energy Efficiency Contest was added. SDE houses’ interior comfort, functioning and energy performance is monitored. The monitoring data can give an idea about the efficiency of the houses. However, a jury comprised by international experts is responsible for carrying out the houses energy efficiency evaluation. Passive strategies and houses services are analyzed. Additionally, the jury's assessment has been compared with the behavior of the houses during the monitoring period. Comparative studies make emphasis on the energy aspects, houses functioning and their interior comfort. Conclusions include thoughts related with the evaluation process, the results of the comparative studies and suggestions for the next competitions.

The increasing depletion of natural resources, combined with a wider set of pressures on the environment, has, in recent years, highlighted the need for a more efficient use of energy and a development process that involves alternative energy sources. Energy efficiency has received much attention as a solution, implying both monetary and emissions savings. However, the latter may be partially offset by the income and demand effects of the former, both in more efficient sectors and in spreading to the wider economy. This is the problem of rebound effects. Taking Spain as a case study, and introducing an energy-related CGE model that develops the inclusion of renewables, this paper evaluates a combination of efficiency initiatives to deliver both reduced energy use by households and a more sustainable supply of energy. Our findings suggest that a package aimed at improving efficiency in household electricity and petroleum use, combined with a more competitive supply of energy from renewable sources, may be the only way to get reductions in all energy use, and thus benefit the economy. Specifically, we consider how this package may lead to positive economic impacts and associated rebound effects, where the latter are focused on a greener energy supply.

This research studied the impacts of the environmental Kuznets curve and the determinants of economic growth for Visegrad countries from 1990 to 2018. This paper reflects on the effects of renewable and non-renewable energy, urban population, foreign direct investment, economic growth, and carbon dioxide emissions. According to our results, the panel of unit root tests showed that the variables under study are integrated into the first differences. Considering the empirical results for the environmental Kuznets curve, we observe that economic growth is positively correlated with pollution emissions; nevertheless, the squared income per capita is negatively impacted by carbon dioxide emissions. Energy consumption increases carbon emissions, and foreign direct investment confirms the pollution halo hypothesis. Therefore, the econometric results showed that renewable energy consumption promotes regional growth. Consequently, urban population and foreign direct investment positively correlate with economic growth.

Temporary housing units (THUs), which are provided after disasters, are crucial in terms of sustainability pillars (economic, social, and environmental). In general, THUs, which are regular houses with minimum space and facilities, incorporate some negative aspects of the building industry. Additionally, as large numbers of THUs are usually provided in a short time and under emergency situations, some negative impacts of these units escalate. In this context, this study aims at reducing some negative impacts of THUs by applying a novel optimization model that maximises sustainability indexes by simulating the design of interior geometries for THUs. This method is based on the coupling of artificial intelligence and a multi-criteria decision-making model for sustainability assessment. The proposed model generates optimal solutions using a backtracking algorithm together with a binary search. To evaluate the sustainability indexes, an Integrated Value Model for Sustainability Assessment (MIVES) is applied. This novel method enables decision makers to automatically generate the most suitable alternative solutions for the early design stage of THUs. The results confirm that small changes in the interior geometric design can remarkably affect the sustainability indexes of THUs. The authors would like to acknowledge the kind support offered by professors and researchers from Shahid Beheshti University, Islamic Azad University, the Polytechnic University of Catalonia, and experts from the Housing Foundation of Islamic Republic of Iran (HFIR), who supported this paper for collecting and improving data. Additionally, the authors would like to thank UPC's Centre for Development Cooperation (CCD) for funding the authors (NO.: 2017-U006 and 2018-U012), which enabled the authors to follow and analyse the recovery program of Kermanshah earthquake. Peer Reviewed

Innovation Districts are rising as the banners of the new urban, economic, and social paradigm and as a solution to the renaissance of inner cities since they expedite the creation and commercialization of new ideas which leverage the city goals and its technologic and economic attributes. The configuration of accurate indicators to measure the degree of achievement of the innovation district goals is one of the main requirements to ensure district proper development. Even when the study of innovation districts is a topic that is increasingly under study, little is still known about the insight, and it is still needed tools that favor their evolution and development. The aim of this paper is two-fold: on the one hand, it seeks to collect and analyze the indicators that have been used in literature to measure the degree of maturity over the course of the 20-year existence of the 22@Barcelona, an area of innovation that transformed an old industrial district into a knowledge-based one. On the other hand, guided by the four dimensions of the Knowledge Base Urban Development theory and the main actors that make up Triple Helix approach, the paper designs a framework of indicators in the four spheres that shape the regeneration of the district, that is, urban, economic, social and governance. As we shall see, a total of 47 indicators are proposed, indicating for each of them: the environment in which it is applied, the main purpose to which it responds, and the main actor with the greatest power of action over it.