Life Cycle Assessment of Thermoelectric Generators (TEGs) in an Automobile Application

In this paper, a possibility to reduce the environmental burdens by employing thermoelectric generators (TEGs) was analyzed with a cradle-to-grave LCA approach. An upscaling technique was newly introduced to assess the environmental impacts of TEGs over its life cycle. In addition to CO2 emissions, other environmental impacts as well as social impacts were assessed using the Life Cycle Impact Assessment Method based on Endpoint Modeling (LIME2). The analysis was conducted under two scenarios, a baseline scenario with a 7.2% conversion efficiency and a technology innovation scenario with that of 17.7% at different production scales. The results showed that while GHG emissions were positive over the life cycle under the baseline scenario, it became negative (−1.56 × 102 kg-CO2 eq/kg) under the technology innovation scenario due to GHG credits in the use phase. An increase in the conversion efficiency of the TEG and a decrease in the amount of stainless steel used in TEG construction are both necessary in order to reduce the environmental impacts associated with TEG manufacture and use. In addition, to accurately assess the benefit of TEG deployment, the lifetime driving distance needs to be analyzed together with the conversion efficiency.

Introducing a Calculator for the Environmental and Financial Potential of Drain Water Heat Recovery in Commercial Kitchens

Food service providers like restaurants, cafes, or canteens are of economic importance worldwide, but also contribute to environmental impacts through water and energy consumption. Drain water heat recovery from commercial kitchens, using a heat exchanger, has shown large potential to decarbonise hot water use across food services, but is rarely deployed. This work translates previous findings on the technical feasibility and heat recovery potential for commercial kitchens into a publicly available calculator. It facilitates decision-making towards recovery and reuse of the freely available heat in kitchen drains by estimating both financial costs and payback time, as well as environmental burdens associated with the installation and environmental savings from avoided energy consumption. Environmental burdens and savings include, but are not limited to, carbon emissions. Further, the tool highlights key aspects of the technical implementation to understand installation requirements. The tool is freely available and could contribute to the uptake of heat recovery in the food service sector, ideally in conjunction with policy support through financial incentives or subsidies.

Towards Higher Quality of Recycled Plastics: Limitations from the Material’s Perspective

The increasing consumption of plastics and plastic products results in correspondingly substantial volumes of waste, which poses considerable environmental burdens. With the ongoing environmental actions, the application of circular economy on this waste stream is becoming inevitable. In this paper, the topics of plastics recycling, circular economy on plastics, and challenges to plastic waste recycling are critically reviewed. In the first part of this paper, the development of research on plastic recycling was viewed from 1950 until 2020 using the scientific database Web of Science, and 682 related studies were found and used to assess the changing research priorities along that timeline. The following sections discuss the potentials and requirements to enhance the quality of the produced recycled plastic, in connection with the factors that currently limit it. In conclusion, the quality of recycled plastic is generally determined by the homogeneity of the recovered plastic feed. There are various strategies which could be implemented to overcome the hindrances identified in the paper and to improve the quality of the recycled plastic, such as working on enhanced product designs for minimised waste heterogeneity and controlling the materials’ degree of contamination by applying advanced sorting.

Life cycle assessment of aquaculture bivalve shellfish production — a critical review of methodological trends

Purpose The increase of shellfish production has raised environmental concerns, i.e., enrichment and redistribution of nutrients and energy consumption. Efforts assessing the environmental burdens arising from the expansion of shellfish production have been made using the life cycle assessment (LCA) methodology. Although LCA has been extensively applied and reviewed in aquaculture systems, shellfish production remains scarcely studied. The objective of this review is to identify methodological trends, highlight gaps and limitations, and provide guidelines for future studies. Methods A systematic literature review was applied to scientific studies published up to 2021. A total of 13 documents were shorted by abstract and full text-screening. Literature meeting the inclusion criteria were further analyzed in six different aspects of a LCA (functional unit, system boundaries, data and data quality, allocation, impact assessment methods, interpretation methods). Discussion and guidelines are provided for each reviewed aspect. Results and discussions Shellfish LCAs differ considerably from other aquaculture studies mainly because shellfish avoids the allocation of impacts derived from the production of fishmeal. Co-products are present when the shellfish is processed, e.g., in canned products. Furthermore, shellfish studies do not take into account the positive credits from the removal of nutrients from the ecosystems and from the valorization of the shellfish waste (shell and organic remains). Limited information was found for countries outside Europe and species different from mussels. Despite the variability on goals and scopes of the studies, methodological trends were found. The local impacts of the shellfish with the farming area and the impacts on biodiversity have not been included into the studies. Conclusions and recommendations Effort should be made in providing the data associated with the fore-background system within the studies in order to improve transparency and to allow the reproduction of the results. Information regarding the natural condition of the cultivation area should be provided as the shellfish production depends mainly on non-anthropogenic conditions. Application of biodiversity assessment methodologies should be encouraged, despite their limitations.

Environmental life cycle implications of upscaling lithium-ion battery production

Purpose Life cycle assessment (LCA) literature evaluating environmental burdens from lithium-ion battery (LIB) production facilities lacks an understanding of how environmental burdens have changed over time due to a transition to large-scale production. The purpose of this study is hence to examine the effect of upscaling LIB production using unique life cycle inventory data representative of large-scale production. A sub-goal of the study is to examine how changes in background datasets affect environmental impacts. Method We remodel an often-cited study on small-scale battery production by Ellingsen et al. (2014), representative of operations in 2010, and couple it to updated Ecoinvent background data. Additionally, we use new inventory data to model LIB cell production in a large-scale facility representative of the latest technology in LIB production. The cell manufactured in the small-scale facility is an NMC-1:1:1 (nickel-manganese-cobalt) pouch cell, whereas in the large-scale facility, the cell produced in an NMC-8:1:1 cylindrical cell. We model production in varying carbon intensity scenarios using recycled and exclusively primary materials as input options. We assess environmental pollution–related impacts using ReCiPe midpoint indicators and resource use impacts using the surplus ore method (ReCiPe) and the crustal scarcity indicator. Results and discussion Remodelling of the small-scale factory using updated background data showed a 34% increase in greenhouse gas emissions — linked to updated cobalt sulfate production data. Upscaling production reduced emissions by nearly 45% in the reference scenario (South Korean energy mix) due to a reduced energy demand in cell production. However, the emissions reduce by a further 55% if the energy is sourced from a low-carbon intensity source (Swedish energy mix), shifting almost all burden to upstream supply chain. Regional pollution impacts such as acidification and eutrophication show similar trends. Toxic emissions also reduce, but unlike other impacts, they were already occurring during mining and ore processing. Lastly, nickel, cobalt, and lithium use contribute considerably to resource impacts. From a long-term perspective, copper becomes important from a resource scarcity perspective. Conclusions Upscaling LIB production shifts environmental burdens to upstream material extraction and production, irrespective of the carbon intensity of the energy source. Thus, a key message for the industry and policy makers is that further reductions in the climate impacts from LIB production are possible, only when the upstream LIB supply chain uses renewable energy source. An additional message to LCA practitioners is to examine the effect of changing background systems when evaluating maturing technologies.

Locally Based, Regionally Manifested, and Globally Relevant: Indigenous and Local Knowledge, Values, and Practices for Nature

The knowledge, values, and practices of Indigenous peoples and local communities offer ways to understand and better address social-environmental problems. The article reviews the state of the literature on this topic by focusing on six pathways by which Indigenous peoples and local communities engage with management of and relationships to nature. These are ( a) undertaking territorial management practices and customary governance, ( b) contributing to nature conservation and restoration efforts with regional to global implications, ( c) co-constructing knowledge for assessments and monitoring, ( d) countering the drivers of unsustainable resource use and resisting environmental injustices, ( e) playing key roles in environmental governance across scales, and ( f ) offering alternative conceptualizations of the interrelations between people and nature. The review shows that through these pathways Indigenous peoples and local communities are making significant contributions to managing the health of local and regional ecosystems, to producing knowledge based in diverse values of nature, confronting societal pressures and environmental burdens, and leading and partnering in environmental governance. These contributions have local to global implications but have yet to be fully recognized in conservation and development polices, and by society at large. Expected final online publication date for the Annual Review of Environment and Resources, Volume 46 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

THE CIRCULAR ECONOMY IN URBAN PROJECTS: A CASE STUDY ANALYSIS OF CURRENT PRACTICES AND TOOLS

Over the last decade, the concept of the circular economy (CE) has gained momentum among practitioners, politicians, and scholars because of its promise of achieving sustainability goals. However, there is still a need to demonstrate and assess the positive environmental impacts of the CE. With respect to the building sector, the CE is still a relatively new topic. To date, research has tended to focus primarily on the macro-scale (cities or eco-parks) and the micro-scale (manufactured products or construction materials). Nevertheless, the often- neglected built environment is also expected to play a crucial role in the transition towards a CE due to its high contribution to various environmental burdens. This paper contributes to this growing area of research by reviewing four cases of ‘circular neighbourhood’ projects in Europe. First, a conceptual framework analysis is defined and applied to the cases. Second, CE initiatives and actions are identified and classified using interviews and document analysis. Third, the use of assessment tools within these CE projects is investigated. The results demonstrate a diverse representation of the CE paradigm and the growing role played by the assessment tools.