Mortars with incorporation of phase change materials (PCM): physical and mechanical properties and durability

O despertar da consciência ambiental pela sociedade, tem levantado problemas até então ignorados tais como os consumos energéticos. Numa sociedade com um elevado ritmo de crescimento e padrões de conforto cada vez maiores, surge a necessidade de minimizar os elevados consumos energéticos, tirando partido de fontes de energia renováveis. As argamassas com incorporação de materiais de mudança de fase (PCM) possuem a capacidade de regular a temperatura no interior dos edifícios, contribuindo desta forma para o aumento do nível de conforto térmico e diminuição do recurso a equipamentos de climatização, apenas com recurso à energia solar. Contudo, a incorporação de materiais de mudança de fase em argamassas modifica algumas das suas principais características. Portanto, o principal objetivo deste estudo consistiu na caracterização física e mecânica de argamassas aditivadas com PCM, assim como na avaliação da sua durabilidade. Para tal foram desenvolvidas 12 composições distintas, à base de diferentes ligantes e dopadas com 40% de PCM. Tendo sido possível observar que a incorporação de PCM provoca diferenças significativas em propriedades tais como a trabalhabilidade, resistência à compressão, resistência à flexão, aderência, absorção de água por capilaridade, absorção de água por imersão e resistência a ações de gelo-degelo. Contudo, foi possível concluir que a incorporação de PCM nas argamassas pode ser realizada com sucesso. Sendo que, as alterações verificadas nas argamassas podem ser contornadas através da incorporação de uma maior dosagem de ligante, superplastificante e até mesmo a inclusão de fibras. Apesar dos resultados desta investigação serem promissores é importante referir que outras investigações devem ser realizadas com o intuito de observar a influência do PCM em argamassas constituídas por outros materiais.The awakening of environmental awareness by society has raised issues previously ignored such as energy consumption. In a society with a high growth rate and increased standards of comfort arises the need to minimize the currently high energy consumption by taking advantage of renewable energy sources. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction of the use of heating and cooling equipment, using only the energy supplied by the sun. However, the incorporation of phase change materials in mortars modifies its characteristics. The main purpose of this study was the physical and mechanical characterization, as well the evaluation of the durability. Twelve compositions were developed, based in different binders and doped with 40% of PCM. It was possible to observe that the incorporation of PCM in mortars caused significant differences in properties, such as workability, compression strength, flexural strength, adhesion, water absorption by capillarity, water absorption by immersion and degradation after freeze-thaw cycles. However, it was concluded that the incorporation of PCM in mortars can be performed successfully. Being that the changes in mortars can be solved by incorporating a higher content of binder, superplasticizer and the inclusion of fibers. Although the results of this investigation are promising it is important to note that further investigations should be performed aiming to observe the influence of PCM in mortars composed by other materials.Fundação para a Ciência e Tecnologia pelo financiamento deste trabalho de investigação desenvolvido no âmbito do projeto “ Contribuição de Argamassas Térmicas Ativas para a Eficiência Energética dos Edifícios” (PTDC/ECM/102154/2008) e à atribuição da bolsa individual de doutoramento com referência SFRH/BD/95611/2013

Life Cycle Assessment (LCA) of Worsted and Woollen processing in wool production: ReviWool® noils and other wool co-products

The textile and fashion industry is becoming increasingly active in measuring its environmental performance. As far as wool is concerned, there is quite abundant literature on environmental impacts available. However, previous studies very rarely distinguish between the different co-products of the wool transformation, and often attribute the same impact to fibers produced from worsted processing (longer and more expensive fibers) and woollen processing (shorter and cheaper fibers). This study firstly provides a detailed mapping of processes and products involved in the wool production chain, from sheep grazing to yarn production, with particular attention to the shorter fibers, which have been mostly neglected in previous literature. Secondly, this study uses the Life Cycle Assessment (LCA) methodology to analyze the environmental impacts of the different intermediate co-products. In particular, when multi-output processes occur, impacts are distributed proportionally to their relative economic value, using therefore an economic allocation. This approach enabled the calculation of environmental impacts of fibers used both in the worsted and woollen processing. It results that shorter fibers generally have lower impacts than longer fibers used for the production of fine yarns. Specifically, most short fibers have an impact on climate change ranging from 25 to 30 kg CO2 eq/kg, while, longer fibers have an impact of 78–97 kg CO2 eq/kg. The physiological variation in the ratio between worsted and woolen co-products of multi-output processes appears to have little effect on the final impact results. Finally, since the grazing phase is highly variable, impacts on climate change of the analyzed intermediate products have been re-calculated using, for the greasy wool, the lowest and highest values of impact found in literature. Impacts of the analyzed products vary sensibly according to the value considered for the greasy wool, but the relationship between them is rather stable. This paper contributes with detailed information and easily replicable data which could be used as a basis for the environmental assessment of wool garments and for improving the sustainability in the wool sector

Life Cycle Assessment (LCA) of MWool® Recycled Wool Fibers

Textile industries are in the spotlight due to the heavy environmental impacts along their products’ life cycle and, at the same time, they are a priority sector in the new circular economy action plan of the European Commission. In this framework, the Italian company Manteco SpA has developed a value chain based on the recycling of pre-and post-consumer discarded textiles, wh0se output is a secondary wool fiber named MWool® . This study develops an environmental analysis of recycled wool fibers through the Life Cycle Assessment (LCA) methodology, mainly using primary data. A parallel LCA is developed of virgin wool fiber, mostly based on literature data. Sensitivity analyses have been carried out: (i) to capture the uncertainty associated with virgin fibers’ impacts and (ii) to evaluate how MWool® impacts vary according to the origin and treatment of recycled textiles. Finally, the Circular Footprint Formula (CFF) has been applied to consider also a possible decay in quality typically affecting recycled fibers. Results show that recycled wool fibers have significantly lower environmental impacts than virgin fibers, even when the most unfavorable scenarios are considered. As climate change is concerned, 1 kg of MWool® has a carbon footprint of 0.1–0.9 kg CO2 eq., while producing virgin fibers releases 10–103 kg CO2 eq. Using the CFF, it emerges that recycled wool fibers can save about 60% of the impacts of virgin fibers. This study contributes to filling data gaps regarding LCAs applied to the textile sector, which is more and more in the spotlight and needs to address these environmental issues

Analysis of long-term statistical data of cobalt flows in the EU

Long-term statistical data was explored, acquired, processed, and analysed in order to assess the historical domestic production and international trade of a number of cobalt-containing commodities in the EU. Different data sources were examined for data, such as the British Geological Survey (BGS), the US Geological Survey (USGS), and the Eurostat and UN Comtrade (UNC) databases, considering all EU-member states before and after they joined the EU. For the international trade, hidden flows related to data gaps such as data reported in monetary value or recorded as “special category” were identified and included in the analysis. In addition, data from the Finnish customs database (ULJAS) was used to complement flows reported by Eurostat and UNC. From UNC, data was obtained considering the member states as reporters or as partners of the trade, due to internal differences of the database. Based on the acquired data the domestic production and international trade of the commodities were reconstructed for the timeframes 1938–2018 and 1988–2018, respectively. Next to the analysis of the trend of the production and trade of the different commodities, the importance of including hidden flows was revealed, where hidden flows represented more than 50% of the flow of a year in some cases. In addition, it was identified that even from reliable data sources, strong differences (more than 100% in some cases) can be found in the reported data, which is crucial to consider when utilizing the data in research

Resource efficient recovery of critical and precious metals from waste silicon PV panel recycling

Although the amount of waste photovoltaic (PV)panels is expected to grow exponentially in the next decades, little research on the resource efficiency of their recycling has been conducted so far. The article analyses the performance of different processes for the recycling of crystalline silicon PV waste, in a life cycle perspective. The life cycle impacts of the recycling are compared, under different scenarios, to the environmental benefits of secondary raw materials recovered. Base-case recycling has a low efficiency and, in some cases, not even in line with legislative targets. Conversely, high-efficient recycling can meet these targets and allows to recover high quality materials (as silicon, glass and silver)that are generally lost in base-case recycling. The benefits due to the recovery of these materials counterbalance the larger impacts of the high-efficiency recycling process. Considering the full life cycle of the panel, the energy produced by the panel grants the most significant environmental benefits. However, benefits due to high-efficient recycling are relevant for some impact categories, especially for the resource depletion indicator. The article also points out that thermal treatments are generally necessary to grant the high efficiency in the recycling. Nevertheless, these treatments have to be carefully assessed since they can be responsible for the emissions of air pollutants (as hydrogen fluoride potentially released from the combustion of halogenated plastics in the panel's backsheet). The article also identifies and assesses potential modifications to the high-efficiency recycling process, including the delocalisation of some treatments for the optimisation of waste transport and the introduction of pyrolysis in the thermal processing of the waste. Finally, recommendations for product designers, recyclers and policymakers are discussed, in order to improve the resource efficiency of future PV panels

Assessment of the methodology for establishing the EU list of critical raw materials : background report

This report presents the results of work carried out by the Directorate General (DG) Joint Research Centre (JRC) of the European Commission (EC), in close cooperation with Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs (GROW), in the context of the revision of the EC methodology that was used to identify the list of critical raw materials (CRMs) for the EU in 2011 and 2014 (EC 2011, 2014). As a background report, it complements the corresponding Guidelines Document, which contains the "ready-to-apply" methodology for updating the list of CRMs in 2017. This background report highlights the needs for updating the EC criticality methodology, the analysis and the proposals for improvement with related examples, discussion and justifications. However, a few initial remarks are necessary to clarify the context, the objectives of the revision and the approach. As the in-house scientific service of the EC, DG JRC was asked to provide scientific advice to DG GROW in order to assess the current methodology, identify aspects that have to be adapted to better address the needs and expectations of the list of CRMs and ultimately propose an improved and integrated methodology. This work was conducted closely in consultation with the adhoc working group on CRMs, who participated in regular discussions and provided informed expert feedback. The analysis and subsequent revision started from the assumption that the methodology used for the 2011 and 2014 CRMs lists proved to be reliable and robust and, therefore, the JRC mandate was focused on fine-tuning and/or targeted incremental methodological improvements. An in depth re-discussion of fundamentals of criticality assessment and/or major changes to the EC methodology were not within the scope of this work. High priority was given to ensure good comparability with the criticality exercises of 2011 and 2014. The existing methodology was therefore retained, except for specific aspects for which there were policy and/or stakeholder needs on the one hand, or strong scientific reasons for refinement of the methodology on the other. This was partially facilitated through intensive dialogue with DG GROW, the CRM adhoc working group, other key EU and extra-EU stakeholders

Can S-LCA methodology support responsible sourcing of raw materials in EU policy context?

Purpose: Access, affordability and sustainability of raw material supply chains are crucial to the sustainable development of the European Union (EU) for both society and economy. The study investigates whether and how the social life cycle assessment (S-LCA) methodology can support responsible sourcing of raw materials in Europe. The potential of social indicators already available in an S-LCA database is tested for the development of new metrics to monitor social risks in raw material industries at EU policy level. Methods: The Product Social Impact Life Cycle Assessment (PSILCA) database was identified as a data and indicators source to assess social risks in raw material industries in EU-28 and extra-EU countries. Six raw material country sectors in the scope of the European policy on raw materials were identified and aggregated among those available in PSILCA. The selection of indicators for the assessment was based on the RACER (Relevance, Acceptance, Credibility, Ease, Robustness) analysis, leading to the proposal of 9 social impact categories. An S-LCA of the selected raw material industries was, thus, performed for the EU-28 region, followed by a contribution analysis to detect direct and indirect impacts and investigate related supply chains. Finally, the social performance of raw material sectors in EU-28 was compared with that of six extra-EU countries. Results and discussion: Considering the overall social risks in raw material industries, “Corruption”, “Fair salary”, “Health and safety” and “Freedom of association and collective bargaining” emerged as the most significant categories both in EU and extra-EU. EU-28 shows an above-average performance where the only exception is represented by the mining and quarrying sector. An investigation of the most contributing processes to social impact categories for EU-28 led to the identification of important risks originating in the supply chain and in extra-EU areas. Therefore, the S-LCA methodology confirmed the potential of a life cycle perspective to detect burdens shifting and trade-offs. However, only a limited view on the sectoral social performance could be obtained from the research due to a lack of social data. Conclusions: The S-LCA methodology and indicators appear appropriate to perform an initial social sustainability screening, thus enabling the identification of hotspots in raw material supply chains and the prioritization of areas of action in EU policies. Further methodological developments in the S-LCA field are necessary to make the approach proposed in the paper fully adequate to support EU policies on raw materials

Life cycle assessment of a renewable energy system with hydrogen-battery storage for a remote off-grid community

Remote areas usually do not have access to electricity from the national grid. The energy demand is often covered by diesel generators, resulting in high operating costs and significant environmental impacts. With reference to the case study of Ginostra (a village on a small island in the south of Italy), this paper analyses the environmental sustainability of an innovative solution based on Renewable Energy Sources (RES) integrated with a hybrid hydrogen-battery energy storage system. A comparative Life Cycle Assessment (LCA) has been carried out to evaluate if and to what extent the RES-based system could bring environmental improvements compared to the current diesel-based configuration. The results show that the impact of the RES-based system is less than 10% of that of the current diesel-based solution for almost all impact categories (climate change, ozone depletion, photochemical ozone formation, acidification, marine and terrestrial eutrophication and fossil resource use). The renewable solution has slightly higher values only for the following indicators: use of mineral and metal resources, water use and freshwater eutrophication. The climate change category accounts for 0.197 kg CO2 eq./kWh in the renewable scenario and 1.73 kg CO2 eq./kWh in the diesel-based scenario, which corresponds to a reduction in GHG emissions of 89%. By shifting to the RES-based solution, about 6570 t of CO2 equivalent can be saved in 25 years (lifetime of the plant). In conclusion, the hydrogen-battery system could provide a sustainable and reliable alternative for power supply in remote areas

Bridging tools to better understand environmental performances and raw materials supply of traction batteries in the future EU fleet

Sustainable and smart mobility and associated energy systems are key to decarbonise the EU and develop a clean, resource efficient, circular and carbon-neutral future. To achieve the 2030 and 2050 targets, technological and societal changes are needed. This transition will inevitably change the composition of the future EU fleet, with an increasing share of electric vehicles (xEVs). To assess the potential contribution of lithium-ion traction batteries (LIBs) in decreasing the environmental burdens of EU mobility, several aspects should be included. Even though environmental assessments of batteries along their life-cycle have been already conducted using life-cycle assessment, a single tool does not likely provide a complete overview of such a complex system. Complementary information is provided by material flow analysis and criticality assessment, with emphasis on supply risk. Bridging complementary aspects can better support decision-making, especially when different strategies are simultaneously tackled. The results point out that the future life-cycle GWP of traction LIBs will likely improve, mainly due to more environmental-friendly energy mix and improved recycling. Even though second-use will postpone available materials for recycling, both these end-of-life strategies allow keeping the values of materials in the circular economy, with recycling also contributing to mitigate the supply risk of Lithium and Nickel