| 1. |
- Andersen, Sarah Cecilie, et al.
(författare)
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Environmental impacts of circularity in the built environment: How do system boundaries affect decision support?
- 2024
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Ingår i: Developments in the Built Environment. - 2666-1659. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Life-Cycle Assessments (LCA) have become a common tool of decision support in the built environment regarding environmental impacts. The goal of this study is to investigate the influence of different LCA approaches and system boundaries on decision support regarding circular design strategies. Three different ways of applying attributional LCA (ALCA) and one consequential LCA (CLCA) are assessed using a case study of a wooden beam with either virgin or reclaimed timber. While the conclusions are not readily scalable, the case study's results indicate that using reclaimed material is environmentally beneficial when applying ALCA. However, when applying CLCA the reclaimed material performs worse than the virgin material. This highlights the potential pitfalls of scaling up solutions based on LCA results without considering the broader consequences. While the current ALCA approach is useful for declarations, it may not provide comprehensive decision support for driving a transition in the built environment.
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| 2. |
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| 3. |
- Ebrahimian, Farinaz, et al.
(författare)
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A biorefinery platform to valorize organic fraction of municipal solid waste to biofuels : An early environmental sustainability guidance based on life cycle assessment
- 2023
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- The biorefining of biowastes, specifically the organic fraction of municipal solid waste (OFMSW), into biofuels and high-value products is an energy-demanding process, still immature, and largely dependent on the process configuration and efficiency of employed microorganisms. Such issues might undermine the environmental sustainability of the biorefinery by inducing adverse impacts on human health, ecosystem quality, climate change, and resources, which need to be explored before the process scale-up. Hence, this study was performed as early sustainability guidance to investigate the environmental impacts of different biorefinery platforms for biofuels production from OFMSW. More specifically, three pretreatment methods (i.e., acetone organosolv, acid, and hot water), two hydrolysis treatments (i.e., acidic and enzymatic), and two fermentation alternatives (i.e., ethanolic fermentation and acetone-butanol-ethanol (ABE) fermentation) were investigated. Based on European Commission's Joint Research Center instruction, the environmental impacts were studied using consequential life cycle assessment for the macro-level decision context. The results demonstrated that ABE fermentation scenarios were not environmentally favorable because the avoided impacts from final products were not sig-nificant enough to compensate for the induced environmental burdens from acetone pretreatment. On the contrary, the ethanolic fermentation scenarios with either acid or hot water pretreatment outperformed both ABE fermentation and ethanolic fermentation with acetone pretreatment. Based on the results, the scenario including simultaneous dilute acid pretreatment and hydrolysis of OFMSW followed by ethanolic fermentation manifested the best performance in all damage categories, as compared to those including acetone pretreatment or higher consumption of enzymes. Such improvements in this scenario led to the highest net saving of-842 potentially disappeared fraction (PDF)/m2/yr,-249.95 kg CO2 eq, and-3275.22 MJ primary per ton of OFMSW on ecosystem quality, climate change, and resources, respectively, and the lowest net burden of 1.54 x 10-5 disability-adjusted life years (DALY) per ton of OFMSW on human health. The results of sensitivity analysis on this scenario demonstrated that the substitution of excess heat for marginal heat with fossil origin can consid-erably decrease impacts on human health.
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| 4. |
- Ekman Nilsson, Anna, et al.
(författare)
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Testing the no agricultural waste concept – an environmental comparison of biorefinery value chains in various regions
- 2021
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Ingår i: Resources, Conservation and Recycling. - : Elsevier B.V.. - 0921-3449 .- 1879-0658. ; 174
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Tidskriftsartikel (refereegranskat)abstract
- Although there is great opportunity, the bioeconomy is not a silver bullet in the quest to solve various environmental problems. This assessment tests the no agricultural waste concept, an agricultural system where all residues are utilized within a value chain, to elucidate whether the concept does indeed improve environmental performance across various regions, and if so, explores how various biorefinery concepts might be organized into various value chains to attain environmental benefits. In order to valorize this, the study illustrates how to do a step-wise assessment in order to design biorefinery set-ups based on their feedstock compatibility and region of implementation. The results show that no agricultural waste systems do not always result in environmental benefits, especially when environmental impacts are measured via a holistic interpretation of environmental damages, namely monetizing environmental damages. Furthermore, disagreement is shown when comparing environmental impacts interpreted via a single impact category, here global warming potential (GWP) and monetized environmental damages (MED). The performance of the various biorefineries was highly affected by the degree of decarbonization present in the energy grid of each region. While energy intensive biorefineries are able to provide benefit in terms of global warming savings, tradeoffs are observed where impacts are shifted to other areas of environmental impact. Despite these tradeoffs, across multiple regions, there is great potential for large-scale implementation of biorefineries as a tool for ameliorating environmental damages.
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| 5. |
- Gontard, Natalie, et al.
(författare)
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A research challenge vision regarding management of agricultural waste in a circular bio-based economy
- 2018
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Ingår i: Critical reviews in environmental science and technology. - : Informa UK Limited. - 1064-3389 .- 1547-6537. ; 48:6, s. 614-654
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural waste is a huge pool of untapped biomass resources that may even represent economic and environmental burdens. They can be converted into bioenergy and bio-based products by cascading conversion processes, within circular economy, and should be considered residual resources. Major challenges are discussed from a transdisciplinary perspective, focused on Europe situation. Environmental and economic consequences of agricultural residue management chains are difficult to assess due to their complexity, seasonality and regionality. Designing multi-criteria decision support tools, applicable at an early-stage of research, is discussed. Improvement of Anaerobic Digestion (AD), one of the most mature conversion technologies, is discussed from a technological point of view and waste feedstock geographical and seasonal variations. Using agricultural residual resources for producing high-value chemicals is a considerable challenge analysed here, taking into account innovative eco-efficient and cost-effective cascading conversion processes (bio-refinery concept). Moreover, the promotion of agricultural residues-based business is discussed through industrial ecology, to promote synergy, on a local basis, between different agricultural and industrial value chains. Finally, to facilitate a holistic approach and optimise materials and knowledge flows management, the connection of stakeholders is discussed to promote cross-sectorial collaboration and resource exchange at appropriate geographic scales. © 2018, © 2018 Nathalie Gontard, Ulf Sonesson, Morten Birkved, Mauro Majone, David Bolzonella, Annamaria Celli, Hélène Angellier-Coussy, Guang-Way Jang, Anne Verniquet, Jan Broeze, Burkhard Schaer, Ana Paula Batista, and András Sebok.
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| 6. |
- Gummidi, Srinivasa Raghavendra Bhuvan, et al.
(författare)
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QUANTIFYING THE SUNK CARBON COSTS OF CITIES: A case study of 50 years of construction in Odense, Denmark
- 2023
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Ingår i: The Routledge Handbook of Embodied Carbon in the Built Environment. - 9781003820031 ; , s. 201-220
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Constructing buildings and infrastructure in cities generates immense emissions of carbon dioxide. Understanding these emissions can aid in low-carbon urban planning and development. Current efforts to estimate these emissions use the Carbon Replacement Value method, which calculates the carbon cost of replacing the urban stock using current technologies. The CRV is useful for forecasting the carbon costs of near-term urban development. However, the perspective of historical emissions from technologies from the time of construction is missing. Quantifying historical emissions would improve our understanding of the embodied carbon spent to build the cities we live in today. This study proposes a methodology to estimate the Sunk Carbon Cost of urban material stocks. This method combines urban material cadastral maps with temporally dynamic life cycle assessment (LCA) of previous construction technologies to quantify and spatialize the historical carbon investment in the urban built form. We demonstrate the method by estimating the historical carbon emissions from concrete in all construction since 1961 (~105,000 individual buildings) in the city of Odense, Denmark. We estimate that 20.2 Mt of concrete was used in these buildings which released 3.0 Mt of carbon dioxide. We find that the sunk carbon cost for all construction since 1961 may be up to ~36% greater than estimates using carbon replacement value, but that these differences decrease for newer buildings. The spatial analysis identifies low-density settlement patterns as spatial hotspots of historical emissions, highlighting the material and carbon efficiencies of high-density neighborhoods. Applying this method to a city’s entire material stock can identify hotspots of embodied emissions across the urban fabric and suggest how to best utilize spent carbon through the adaptive reuse of existing buildings and low-carbon urban design.
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| 7. |
- Leipold, Sina, et al.
(författare)
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Lessons, narratives, and research directions for a sustainable circular economy
- 2023
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Ingår i: Journal of Industrial Ecology. - : Wiley. - 1088-1980 .- 1530-9290. ; 27:1, s. 6-18
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Tidskriftsartikel (refereegranskat)abstract
- The current enthusiasm for the circular economy (CE) offers a unique opportunity to advance the impact of research on sustainability transitions. Diverse interpretations of CE by scholars, however, produce partly opposing assessments of its potential benefits, which can hinder progress. Here, we synthesize policy-relevant lessons and research directions for a sustainable CE and identify three narratives—optimist, reformist, and skeptical—that underpin the ambiguity in CE assessments. Based on 54 key CE scholars’ insights, we identify three research needs: the articulation and discussion of ontologically distinct CE narratives; bridging of technical, managerial, socio-economic, environmental, and political CE perspectives; and critical assessment of opportunities and limits of CE science–policy interactions. Our findings offer practical guidance for scholars to engage reflexively with the rapid expansion of CE knowledge, identify and pursue high-impact research directions, and communicate more effectively with practitioners and policymakers.
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