• Energy Research

The number of end-of-life (EoL) lithium-ion batteries (LIBs) has increased worldwide. Yet, current recycling technologies are unoptimized. In this study, a recycling route consisting of LIB dismantling, discharge, cell opening, thermal pretreatment, leaching and precipitation was investigated in a life cycle assessment (LCA) approach. The final goal of the study was to understand the process feasibility, by adopting hotspot and scenario analyses, and economic evaluation as supporting tools. Primary data was used as input for the LCA. Under the base scenario, recycling credits were obtained for the categories of terrestrial toxicity, human non-carcinogenic toxicity, and mineral resource scarcity. Citric acid use was the main contributor to overall impacts in 13 out of 18 impact categories. The analysis of the best-case scenario, which simulated possible improvements during scale-up, resulted in reduced impacts for every impact category as compared to the base scenario. Citric acid reuse was essential for impact mitigation. The improved recycling process (best-case) of 1 battery pack (3.8 kg, 148.5 Wh) led to credits in the categories of mineral resource scarcity (−0.278 ± 0.0105 kg Cu eq), human non-carcinogenic toxicity (−34.3 ± 1.9 kg 1,4-DCB eq), marine ecotoxicity (−3.05 ± 0.204 kg 1,4-DCB eq), freshwater ecotoxicity (−2.46 ± 0.162 kg 1,4-DCB eq), terrestrial ecotoxicity (−178 ± 8.69 kg 1,4-DCB eq), and freshwater eutrophication (−0.00095 ± 0.000154 kg P eq). A preliminary economic evaluation resulted in revenues of €298.59 ± 12.93 and material and energy costs of €97.42 ± 1.95 per battery pack. Anode recovery was profitable.

The number of end-of-life (EoL) lithium-ion batteries (LIBs) has increased worldwide. Yet, current recycling technologies are unoptimized. In this study, a recycling route consisting of LIB dismantling, discharge, cell opening, thermal pretreatment, leaching and precipitation was investigated in a life cycle assessment (LCA) approach. The final goal of the study was to understand the process feasibility, by adopting hotspot and scenario analyses, and economic evaluation as supporting tools. Primary data was used as input for the LCA. Under the base scenario, recycling credits were obtained for the categories of terrestrial toxicity, human non-carcinogenic toxicity, and mineral resource scarcity. Citric acid use was the main contributor to overall impacts in 13 out of 18 impact categories. The analysis of the best-case scenario, which simulated possible improvements during scale-up, resulted in reduced impacts for every impact category as compared to the base scenario. Citric acid reuse was essential for impact mitigation. The improved recycling process (best-case) of 1 battery pack (3.8 kg, 148.5 Wh) led to credits in the categories of mineral resource scarcity (−0.278 ± 0.0105 kg Cu eq), human non-carcinogenic toxicity (−34.3 ± 1.9 kg 1,4-DCB eq), marine ecotoxicity (−3.05 ± 0.204 kg 1,4-DCB eq), freshwater ecotoxicity (−2.46 ± 0.162 kg 1,4-DCB eq), terrestrial ecotoxicity (−178 ± 8.69 kg 1,4-DCB eq), and freshwater eutrophication (−0.00095 ± 0.000154 kg P eq). A preliminary economic evaluation resulted in revenues of €298.59 ± 12.93 and material and energy costs of €97.42 ± 1.95 per battery pack. Anode recovery was profitable.

The growth in the relevance of the circular economy is confirmed today by the presence of numerous concurrent initiatives at a global level in terms of both policy level and labelling initiatives. Despite the presence of these initiatives, there is still no international agreement on systems to measure this effort. The ISO/TC 323 initiative aims precisely to develop responses to this challenge over the next three years. This article presents the main features of this initiative, in particular WG3 at a global level and the parallel UNI/CT 057 initiative.

The growth in the relevance of the circular economy is confirmed today by the presence of numerous concurrent initiatives at a global level in terms of both policy level and labelling initiatives. Despite the presence of these initiatives, there is still no international agreement on systems to measure this effort. The ISO/TC 323 initiative aims precisely to develop responses to this challenge over the next three years. This article presents the main features of this initiative, in particular WG3 at a global level and the parallel UNI/CT 057 initiative.

This paper reports a novel and simplified approach for sustainability evaluation of new technologies, based on the use of two parameters (i.e. embodied energy and CO2 footprint) that account for the energy and emissions involved in the formation of a material, suitable to perform pre-screening analysis, preliminary to life cycle assessment. This new approach is presented and used to compare the available technologies for phosphorous recovery from sewage sludge ash. A dimensionless index, defined as SUB-RAW index, is used to compare the results about the environmental impact of each selected substituting material/process. This method is applied to full, pilot, and laboratory scale processes available in literature in the context of phosphorus extraction technologies. The results show that wet chemical leaching approaches appear to be the most sustainable methods.

This paper reports a novel and simplified approach for sustainability evaluation of new technologies, based on the use of two parameters (i.e. embodied energy and CO2 footprint) that account for the energy and emissions involved in the formation of a material, suitable to perform pre-screening analysis, preliminary to life cycle assessment. This new approach is presented and used to compare the available technologies for phosphorous recovery from sewage sludge ash. A dimensionless index, defined as SUB-RAW index, is used to compare the results about the environmental impact of each selected substituting material/process. This method is applied to full, pilot, and laboratory scale processes available in literature in the context of phosphorus extraction technologies. The results show that wet chemical leaching approaches appear to be the most sustainable methods.

Energy production from biomass is very strategic for the achievement of global sustainability goals and the use of biofuels for decentralized energy production in medium-small size plants, which conforms to global fossil energy and GHG reduction targets, is expected to increase in the short-medium term.This paper proposes a simplified methodology for estimating the Carbon Footprint associated with heat generation by forest woodchips. The methodology includes all the relevant life cycle phases and is based on the specific fuel and plant characteristics, so it can effectively support sustainability assessment in decision-making regarding biomass projects through proper Carbon Footprint estimates.The application of the methodology showed results in the range of about 6–12 gCO2eq/MJ, depending on the case study characteristics, that agree with the impact values range observed from previous literature. The basic idea that the use of forest woodchips is particularly strategic for sustainable energy production within a “local” wood-energy supply chain (short transport distance) was confirmed. Furthermore, the methodology allowed to estimate indicative transportation distances for which forest woodchips can be considered environmentally competitive compared to alternative renewable sources such as, for instance, wood pellets.

Energy production from biomass is very strategic for the achievement of global sustainability goals and the use of biofuels for decentralized energy production in medium-small size plants, which conforms to global fossil energy and GHG reduction targets, is expected to increase in the short-medium term.This paper proposes a simplified methodology for estimating the Carbon Footprint associated with heat generation by forest woodchips. The methodology includes all the relevant life cycle phases and is based on the specific fuel and plant characteristics, so it can effectively support sustainability assessment in decision-making regarding biomass projects through proper Carbon Footprint estimates.The application of the methodology showed results in the range of about 6–12 gCO2eq/MJ, depending on the case study characteristics, that agree with the impact values range observed from previous literature. The basic idea that the use of forest woodchips is particularly strategic for sustainable energy production within a “local” wood-energy supply chain (short transport distance) was confirmed. Furthermore, the methodology allowed to estimate indicative transportation distances for which forest woodchips can be considered environmentally competitive compared to alternative renewable sources such as, for instance, wood pellets.

Construction and demolition waste (CDW) reuse and recycling represents a key point to enhance resource efficiency in construction sector and to reduce the huge volumes of extracted materials, energy consumption and waste production, which make this sector the largest resource consuming and waste producing one. Even if several alternatives for raw materials substitution have been widely investigated from a technical and economic point, several critical issues hinder a wide substitution rate of virgin raw materials with CDW valorised streams slowing down the circular economy transition. The aim of this research was to individuate and discuss these issues hindering a widespread CDW recycling practice in order to individuate actions to undertake, that can support policies and action plans. The investigation was conducted through desk research and a survey, through the administration of questionnaires and more focused guided interviews. Difficulties and barriers have been analysed and suggestions to improve waste recycling and reuse have been proposed. The state of implementation of policies, actions and best practices such as Green Public Procurement (GPP); b) End of Waste (EoW) criteria; c) pre-demolition audit; d) selective demolition; e) landfill tax; f) tax on raw material extraction; g) traceability system; h) take-back centres, have been examined and discussed. Finally, ideas and suggestions aimed at directing the correct implementation of policies, initiatives and action plans, starting from the successful experiences of some countries that could be effectively transferred in other ones and, trying to take advantage of the difficulties encountered in the implementation process, have been proposed.