Life Cycle Assessment Standards Research Articles

Life Cycle Assessment of Brazilian Bleached Eucalyptus Kraft Pulp: Integrating Bleaching Processes and Biogenic Carbon Impacts

Bleached eucalyptus kraft (BEK) pulp dominates global pulp production, yet the environmental impacts of its bleaching sequences in Brazil are not fully explored. Addressing this gap, we conducted a comparative life cycle assessment (LCA) of three bleaching sequences: conventional elemental chlorine-free (ECF), ECF with oxygen delignification, and ECF with oxygen delignification plus acid washing. We estimated the average global warming potential (GWP) for BEK delivered to the U.S. and examined how forest carbon cycle (FCC) elements, specifically biogenic GWP (GWPbio) and potential soil organic carbon (SOC) sequestration, influence GWP outcomes. Results show that the ECF sequence with oxygen delignification and acid washing reduces GWP by 11% and outperforms conventional ECF in 10 out of 11 environmental impact categories. The average GWP for Brazilian BEK delivered to the U.S. is 576 kg CO₂-eq/ton. Sensitivity analyses demonstrate that adding GWPbio increases GWP by 18%, whereas accounting for potential SOC sequestration reduces it by 39%. These findings highlight the necessity of optimizing bleaching processes and developing a standardized BEK LCA model for comparing the environmental impact of different fibers. This work sets a precedent for integrating FCC elements into LCAs and underscores the potential of SOC sequestration in mitigating climate change impacts.

LCA standards for environmental product assessments in the bioeconomy with a focus on biogenic carbon: A systematic review

Abstract Purpose Climate change mitigation is one of the priorities of the European Bioeconomy Strategy (BES). In this regard, renewable raw materials are a crucial resource, as they help to substitute fossil resources and reduce greenhouse gas (GHG) emissions by storing biogenic carbon (C). To control the environmental impact of the European BES, the life cycle assessment (LCA) is the preferred method. Standards provide guidance for LCA. This review aims to present the state of the art of LCA-related standards, focusing on the assessment of biogenic C and its global warming potential (GWP) to evaluate them for decision-making with regard to the transition to a bioeconomy (BE) and climate change mitigation. Methods A systematic review is conducted using the database Nautos to reveal the relevant standards guiding LCA in the BE. In an iterative process, criteria for a comparative analysis are defined. The eligible standards are then qualitatively analysed and compared based on criteria previously derived in the iterative process. Results and discussion In the context of LCA and bio-based products, 13 documents are identified. Differences are revealed in the accounting of biogenic C flows, the calculation of the duration of biogenic C storage and the biogenic C content as well as the consideration of substitution effects. Furthermore, the standards do not provide any information on the assessment of biogenic C in the circular economy so far. Conclusion The importance of biogenic C aspects in LCA has been reflected in the standards over the last 20 years. However, further research is needed to harmonise the different aspects and integrate new relevant ones related to biogenic C and BE to support decision-making for the transition to a BE. This becomes more important as new legislation refers to LCA standards as the preferred assessment method.

Life cycle assessment of photovoltaic panels including transportation and two end-of-life scenarios: Shaping a sustainable future for renewable energy

This research study addresses the growing environmental concerns associated with solar photovoltaic (PV) systems which is a pivotal component of renewable energy transition. The primary objective is to advance the comprehension of the environmental sustainability of solar PV technology, with a specific focus on the context of Mexico. This study applies a life cycle assessment (LCA) framework, employing an up-to-date methodology (ReCiPe 2016) and database (Ecoinvent 3.8) for midpoint and endpoint indicators in this problem by considering a specific focus on end-of-life and transportation scenarios which have been absent in the current state-of-the-art research. An LCA approach bridges the gap between midpoint and end-point indicators, bringing transparency to the environmental impact assessment. This research entails a cradle-to-grave LCA of a 1 kW crystalline silicon solar panel over a 25-year lifespan while adapting to ISO 14044 standards for LCA and encompassing both midpoint and end-point indicators, specifically including end-of-life and transportation scenario. Furthermore, a sensitivity analysis is conducted to evaluate the variations in environmental indicators considering the life-cycle data. It is reported that recycling processes can cause a substantial mitigating effect on environmental impacts across multiple categories, leading to reductions of up to 89 % in mineral resource scarcity. Notably, the cell processing phase emerges as the most environmentally impactful stage, accounting for 37 % of the total impact. This high impact is predominantly attributed to silver usage and heightened electricity consumption. The sensitivity analysis revealed that various performance indicators exhibited differing degrees of sensitivity to uncertainty in the design variables, highlighting the importance of careful consideration, particularly in addressing theimpact on theecosystem, when aiming to reduce environmental impacts in the life cycle of silicon solar panels. Our results have also indicated that transportation significantly impacts resource protection, accounting for 15 % of the total impacts in this category, with lesser yet notable contributions to ecosystems and human health. The implications of this work suggest a need for stringent policies to fabricate complete solar photovoltaic modules in Mexico to reduce the environmental burden caused by transportation. Additionally, the insights from this study offer a gateway for the Mexican government to reform current energy transition policies by including multiple recycling scenarios for solar photovoltaic systems, ultimately leading to sustainable growth in this market.

Environmental and economic life cycle assessment of emerging sludge treatment routes

Before implementing large-scale emerging sludge treatment methods, it is crucial to conduct a comprehensive analysis of their environmental impacts and economic costs at the system level. This study utilizes standardized Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) accounting methods to evaluate four emerging sludge treatment routes: anaerobic fermentation (AF), pyrolysis (PY), hydrothermal carbonization (HTC), and alkaline thermal hydrolysis (ATH). These routes are compared with two traditional sludge treatment routes, anaerobic digestion (AD) and aerobic composting (AC). The results indicate that the conventional route AD is the optimal choice in terms of environmental pollution, carbon emission control, and life cycle cost. The emerging routes AF and ATH have significant environmental benefits from carbon source recovery and protein recovery. However, they require approximately twice the cumulative energy demand of AD and additional consumption of chemicals, which imposes a greater environmental burden. While PY and HTC outperform the conventional sludge treatment routes in terms of the total environmental impact (1.79E-10, 1.72E-10) due to energy recovery and the use of clean energy sources. AF and PY demonstrate better economic performance (842.11 and 712.00 CNY) compared to the traditional route AC (905.06 CNY). However, both HTC and ATH incur costs approximately 1.3 times higher than AC due to their high energy and material demands. Furthermore, sensitivity analysis reveals that emerging treatment routes are highly influenced by energy and resource recovery and consumption. Therefore, reducing the energy and resource inputs for emerging routes could significantly decrease their environmental impact and cost, maximizing their resource recovery advantages.

Actual sources of life cycle impacts: Elementary processes and flows causing environmental impacts for a typical Brazilian building

Life Cycle Assessment (LCA) is a valuable tool to enhance the environmental performance of buildings. However, the increasing number of impact categories required by construction LCA standards makes it difficult to collect primary data and understand LCA results. Furthermore, most LCA studies only analyse aggregated impact results, failing to identify the specific processes that should be optimized to mitigate environmental impacts. This work shows the additional insights that can be gained from analysing disaggregated LCA results. We identify the specific elementary processes and flows causing each environmental impact for a typical Brazilian building used as a case study. This cradle-to-grave LCA study covers the 16 impact categories required by EN 15804. The findings reveal that the environmental impacts of buildings are primarily caused by a few elementary processes and flows. Multiple impact categories share common sources, implying that at least half of the indicators convey redundant information for decision-making as they point to the same actions for mitigating those impacts. Additionally, some impacts are caused by background elementary processes beyond the influence of construction stakeholders. Interpreting LCA results at the elementary process level allows us to reflect on the suitability of LCA to support decisions. It suggests potential strategies to streamline the LCA scope currently specified in construction LCA standards by excluding redundant indicators or impacts determined by uncontrollable background processes. Streamlining LCA can expedite the adoption of the life cycle approach in the construction sector and improve its contribution to informed decision-making.

What's next for the Sustainable Development Goals? Synergy and trade-offs in affordable and clean energy (SDG 7)

This Sustainable Development Goal (SDG 7) analysis addresses critical challenges through three questions, backed by literature and evidence. Environmental, social, and governance concerns were discussed. A notable SDG target shortfall was observed from International Renewable Energy Agency, International Energy Agency, and United Nation’s publications. Urgent actions include refining greenhouse gas emission equivalent estimations and establishing unified life cycle assessment standards. While prioritizing renewables, minimizing dependence on non-renewables for a lower carbon footprint is vital. Balancing energy production with per capita consumption reduction, especially with a growing population, is key to achieving net-zero emissions. This solution demands a thoughtful evaluation of challenges tied to specific renewable technologies and their socio-economic impact. Balancing economic growth, crisis response, and resource management is crucial for acheiving SDG 7 targets.

Deconstructing and Reconstructing the Theoretical Basis of the Ecological Scarcity Method

The ecological scarcity method (ESM) is a widely used system for assessing the environmental impact of pollutant emissions and resource extractions in the context of life cycle assessment (LCA). Its mathematical principles have been described in various reports, but not in scientific journals, which typically only quote the ESM or challenge the numerical values of the targets. It is, therefore, appropriate to carefully dissect the method and critically reassemble the resulting fragments. Our analysis introduces a substantial number of modifications, in terms of overall formulation, detail and interpretation, while it respects most of the existing numbers and is still applicable to the full range of pollutants and resources. It also yields the conclusion that, although the developers of ESM have tried to align the approach with the ISO 14040/14044 standards for LCA, this attempt has been less successful than foreseen. We finally conclude that the reference to ESM as a “distance-to-target” method further obscures the interpretation of the method.

Life cycle assessment of higher education institutions – method and case study

Against the backdrop of climate change and resource depletion, sustainability and sustainable development has been brought in the focus of industries and organisations. To quantify the environmental impacts of products and organisations the methodology of life cycle assessment (LCA) is applied area-wide in many different sectors. The higher education sector in particular has an important role to play in sustainable development due to the multiplier role by educating the academic employees of the future. Additionally, higher education institutions (HEIs) are a relevant sector by themselves due to their size and number of employees as well as their impact on innovation and future technologies. Therefore, HEIs should be at the forefront of assessing and reducing their environmental impact. In contrast to this an analysis of the available LCAs of HEIs shows significant limitations with regards to availability of assessments as well as guidelines on assessment methodologies. To contribute to closing this gap and increase the availability of LCA information for HEIs, a guideline is developed based on current LCA standards, which contains assistance regarding the goal and scope definition, life cycle inventory and life cycle impact assessment. The guideline is applied in a case study for Leibniz Universität Hannover (LUH), one of the nine leading technical universities in Germany. Results of the case study show that the major contributors for the impact of the LUH are the transport activities, infrastructure and energy supply. In 13 of the 16 assessed impact categories, transport activities account for the largest share of potential environmental impacts, ranging from about 43% to 82%. However, the results of the case study must be considered with care as primary data availability from the LUH has been limited and therefore must be extended in the future.

Turning dynamic LCA principles into practice

The building and construction sector quantifies the environmental impacts of buildings using the Life Cycle Assessment (LCA) method. To put LCA into practice often simplified application of the LCA method is used, without considering timely aspects. Instead, the method dynamic LCA includes timely aspects, which are more complex in the modeling and thus difficult to apply. To investigate the consequences of using the dynamic LCA method, this study develops a tool that takes data available in a simple LCA tool that follows the standardized LCA method and calculates dynamic LCA results. The tool reimplements the calculation engine from the simple LCA tool and adds the more complex aspects of dynamic LCA afterward. Doing so makes it possible to add other complex methods to the original calculation engine to help investigate more complex methodological aspects in the future.

Environmental potential of fungal insulation: a prospective life cycle assessment of mycelium-based composites

PurposeBio-based insulation materials are one of the most promising solutions for reducing the environmental impacts of building envelopes. Among these materials, the environmental benefits of mycelium-based materials have merely been investigated, despite their promising technical and thermal properties. In this paper, we perform a first prospective cradle-to-grave life cycle assessment (LCA) of mycelium-based composite blocks.MethodsAn attributional cradle-to-gate LCA of the laboratory production of mycelium-based composites was first performed, including 11 environmental impact indicators. Then, scenarios were defined to scale up the technology to the level of industrial production, including the remaining life cycle modules to perform a cradle-to-grave analysis. Biogenic and metabolic carbon were considered by applying the static −1/+1 approach and following the current LCA standards. Future-oriented energy and transport mixes were also included as an additional scenario, systematically modifying both the foreground and background data. Finally, the industrially scaled-up technology and alternative insulation materials were compared with these future conditions (as applied to both materials).Results and discussionConsidering climate change, the results are encouraging in comparison to those for traditional plastic insulation, but do not necessarily surpass those for other existing materials such as rock wool. However, trade-offs are observed in other indicators, for which mycelium-based composites tend to perform worse than traditional insulation materials. The industrial scale-up reduced impacts for most indicators, but a considerable trade-off was observed with regard to terrestrial ecotoxicity. The main driver for the remaining greenhouse gas (GHG) emissions was found to be the electricity use during the manufacturing phase. We consider the inclusion of the other life cycle stages as relevant, as this increased the GHG emissions by 10%. Limitations of the current LCA standards, however, are noted and discussed, especially regarding the cascading use of biogenic materials, and highlight the relevance of this case study.ConclusionsMycelium-based composites show a potential for future development, but careful attention should be paid to reducing electricity needs in their manufacturing process. Further improvements could also be made by using fast-growing biogenic materials as a substrate. In particular, we encourage researchers to include all of the life cycle stages in future studies, especially if biogenic emissions are considered.

Overcoming challenges in life cycle assessment of smart energy systems – A map of solution approaches

Current research underlines the benefits of digitalization to integrate renewable energy sources (RES) efficiently and to coordinate generation and supply. This development towards smart energy systems (SES) includes emerging use cases at the distribution grid level, e.g., smart charging strategies for electric vehicles or energy management systems in buildings. An environmental assessment of such, however, is challenging. The standardized Life Cycle Assessment (LCA) approaches seem insufficient since SES are emerging systems at the interface of digitalization and energy with multiple intended and unintended environmental effects. This article aims to derive solution approaches for LCA professionals that investigate use cases enabled by information and communication technology (ICT), specifically in SES. To identify challenges during the first two phases of an LCA and solution approaches, we examine seven recent research projects and conduct a real-time Delphi workshop with LCA experts in the field of SES. As a result, the article provides approaches on setting up an LCA, filling data gaps, and methods to draw upon the long-term impacts of use cases in SES. Key findings include a modified taxonomy of potential environmental effects. Results show that systemic effects in SES have potentially the highest impact on the LCA, followed by effects caused by user behavior. Assessing these effects of ‘higher-order’ poses an increased complexity. Determined solution approaches include combining the standardized LCA with energy system modeling or surveys on user behavior. Overall, this article reveals orientation strategies and recommendations to guide LCA professionals toward a holistic environmental assessment of use cases in SES.

Life Cycle Assessment of the Environmental Benefits of Using Wood Products and Planting Trees at an All-Electric University Laboratory

Many countries across the globe have set targets for different economic sectors, aiming to tackle global warming by reducing the overall carbon footprint of human-related activities. Among these sectors, the building industry stands out as a major consumer of materials and energy resources, making it a key player in achieving carbon neutrality. It is one of the main contributors responsible for energy-related greenhouse gas (GHG) emissions, including both operational emissions and embodied emissions in materials and equipment manufacturing. Nature-based design solutions, such as planting trees in urban spaces, or incorporating the use of wood products, have regained attention in recent years due to their potential to mitigate carbon emissions from buildings. Within this context, this paper presents a comprehensive life cycle assessment (LCA) of a recently built research facility, with a focus on demonstrating how the benefits of nature-based solutions, specifically carbon sequestration from trees and biogenic carbon content in wood products, can be quantified and reported using the latest LCA standards and tools. The analysis is provided under three end-of-life scenarios for wood products: wood incineration with energy recovery, wood landfilling, and wood recycling/repurposing. The results indicate that the set of strategies adopted in this building, i.e., tree planting, the use of wood products, and the end-of-life treatment of materials, can potentially offset carbon emission by 37.2% up to 83.9% when included in the LCA, depending on the scenario considered. By continuing to refine LCA standards and tools, and fostering collaboration between researchers, policymakers, and industry professionals, we can advance our understanding and ultimately achieve the widespread adoption of carbon-neutral buildings.

Electricity accounting in life cycle assessment: the challenge of double counting

PurposeIn grid electricity consumption models, the location-based method uses regional average emission factors to account for environmental impacts. The market-based method is based on contractual agreements, verifying the exclusive claim on electricity from specific energy sources. An inconsistent application of these methods in life cycle assessment (LCA) and GHG accounting can lead to double counting. Especially, double counting electricity associated with rather low environmental impacts, such as renewable energy, might lead to impact underestimations. The aim of this paper is to identify, describe and propose solutions to double counting challenges.MethodsA four-step procedure is carried out. First, the specifications on grid electricity mix selection in frequently applied standards for LCA and GHG accounting are analysed. Besides the ISO norms for LCA (14040/44) and carbon footprinting (14064/67), the GHG Protocol and the Product and Organizational Environmental Footprint (PEF/OEF) are considered. Based on this analysis, challenges of double counting electricity from specific sources are identified. In the third step, potential solutions for avoiding double counting are proposed. The last research step consists of an illustrative case study to demonstrate the calculation of market-based electricity mixes and identify potential adjustments necessities for LCA application.Results and discussionA parallel application of the location-based and the market-based method poses the main double-counting challenge. Thus, avoiding double counting demands consistent method application throughout the whole life cycle. Whereas this is relatively straightforward for the location-based method, consistent market-based method application is more challenging. LCAs rely on average life cycle inventory processes, which mostly include location-based electricity mixes. However, for consistent market-based method application throughout the life cycle, electricity-related environmental impacts in the inventory system also need to be market-based. This would demand a partial recalculation of LCI datasets using market-based residual electricity mixes. Besides illustrating the calculation of market-based electricity mixes, the case study is used to identify and propose solutions for two main challenges for residual mix application in LCA: countries without residual mix and electricity under a double marketing ban.ConclusionDouble counting of electricity from specific energy sources is a challenge, since it can lead to under- or overestimations of environmental impacts. Both the location-based and market-based method can avoid double counting. However, parallel or inconsistent applications of both methods lead to double counting. In order to avoid double counting, there is a need to enable and use consistent electricity accounting rules in LCA and GHG accounting.

Performance evaluation of desulfurization and environmental impact of using waste from mines as adsorbent

This study aims to reduce the environmental impact of impurity adsorption systems on hydrogen production. Biomass is a carbon-neutral hydrogen fuel with a low environmental impact. However, during the production of biomass-derived hydrogen (biohydrogen), the hydrogen sulfide contained in the gasified biomass reduces the performance of fuel cells when hydrogen is used. Generally, hydrogen sulfide (H 2 S) is removed via impurity adsorption. However, common adsorbents such as metal oxides have a significant environmental impact. Therefore, adsorbents with lower environmental impacts are required. Thus, to improve metal depletion from the circular economy perspective, this study proposes using neutralized sediment, a waste product from the mining wastewater treatment, as an H 2 S adsorbent. In this study, we discuss the environmental impact of H 2 S adsorption systems that use neutralized sediments as adsorbents. Although the use of waste materials has a small environmental impact, it is necessary to consider the environmental impact of the inputs and outputs related to waste material generation based on life cycle assessment (LCA). Because fossil fuel-generated electricity and chemical neutralizers are input in mine wastewater treatment, the use of neutralized sediment may have a large environmental impact than the use of metal oxides from the viewpoint of LCA. Therefore, we quantitatively evaluated the environmental impact of neutralized sediment using LCA and investigated whether the environmental impact of using neutralized sediment is less than that of using metal oxides. In addition, it is not appropriate to include the production stage in the system boundary to meet the LCA standards because mineral water treatment, which is the production stage of neutralized sediment, is conducted whether neutralized sediment is utilized or not as an H 2 S adsorbent. Therefore, an LCA that does not include the production stage was also conducted to indicate the environmental benefit of waste utilization according to the actual situation. The amount of neutralized sediment used, which is calculated by the sulfur capture capacity, is necessary for the LCA calculation. However, the sulfur capture capacity of neutralized sediment has never been investigated. Hence, dynamic adsorption tests were conducted during gasification at low (40–120 °C) and high (200–300 °C) temperatures to investigate the sulfur capture capacity of the neutralized sediment in each temperature range. The results showed that the sulfur capture capacity of the neutralized precipitates was 2.28 (at 40 °C) and 5.73 (at 300 °C) g S/100 g sorbent. The results of the LCA, with and without including the neutralized sediment production process, based on the sulfur capture capacity, demonstrated that the use of neutralized sediment as an adsorbent improved the global warming potential (GWP) by 75.1% and 98.9%, respectively, compared with the use of metal oxides. In other words, this study quantitatively indicated that the use of neutralized sediment as H 2 S adsorbents has a smaller environmental impact than existing adsorbents and shows the importance of considering the actual situation in LCA for waste utilization.

Materials role in pavement design and its impacts in LCA of road construction and use phase

Connecting real material databases at a very early stage enables to measure, predict and support informed decision making based on energy and carbon performance in the infrastructure sector. While, in the past twenty years, a significant increase of Life Cycle Assessment (LCA) research for road construction projects was seen, data collection and management still remains one of the main challenges. Having a capability to combine the planning, execution, maintenance and recycling on one platform greatly contributes to reducing the effort and assessment execution time and early stage decision makings. ORIS is the first web-based material platform enabling more sustainable road construction with optimised solutions, bringing an assessment of different pavement design options within a geolocalised material sourcing environment. Based on the embedding local design catalogues and its automatized data-driven approach, an exhaustive LCA analysis is performed on road for its whole life cycle conformed to LCA standards. A case study in the United Kingdom demonstrated the life cycle carbon and cost assessment with a significant contribution of use phase modules (30-40% of the total) and the potential of 56% reduction in the global warming indicator from the product and construction phase and 24% in total life cycle saving 720 k£.

Unlocking New Value from Urban Biowaste: LCA of the VALUEWASTE Biobased Products

The VALUEWASTE project can offer a sustainable solution to transform biowaste into added-value bioproducts, such as proteins from microorganisms and insects and biofertilizers. The present study focused on the environmental impacts linked to obtaining these bioproducts, which was performed by the standardized Life Cycle Assessment (LCA) approach, using the Environmental Footprint methodology to evaluate the midpoint impact categories considered. At the same time, the bioproducts coming from biowaste were compared to regular ones: other protein sources and mineral fertilizers. The study results show that these new protein sources are firm candidates to reach the market from an environmental point of view. Furthermore, their environmental impacts could be improved by reducing the energy use (the main contributor) within some impact categories, such as ecotoxicity and global warming. In case of the biofertilizers, their environmental performance was overall worse compared to mineral fertilizers, except for the following impact categories: mineral and metal use and water scarcity. Nevertheless, these biofertilizers come from biowaste, extending the circularity concept, and from local places, reducing the dependency on other actors. Hence, the study showed that the obtained bioproducts are real alternatives to implement in a circular economy. However, continuous improvement of the solution should be performed.

Level(s) compared to European and Norwegian standards for life cycle assessment of buildings

Launched in 2021, the EU Level(s) calculation method for Global Warming Potential (GWP) of buildings could get increasing attention and complement the standards that are currently used in Europe and Norway, EN 15978 and NS 3720. To understand the possibility and consequences of using Level(s) in Norway, we assess how the Level(s) GWP calculation method differs from EN 15978 and NS 3720, and whether it is more specific and provides more guidance. Comparing fifteen methodological aspects, eleven were treated differently in the three methods. Both Level(s) and NS 3720 are based on EN 15978, hence they provide more, though different, specifications and guidelines than EN 15978 for most of the aspects, such as scope of building elements, life cycle stages to include, and reference study period. Level(s) provides more guidance for the development of scenarios for the operational and end-of-life stages, and for assessing data reliability. NS 3720 lists the scope of building elements in detail and accounts for operational transport (stage B8). Overall, a building GWP calculated with NS 3720 would need some adjustment to reflect the prescriptions of Level(s). These findings inform LCA assessors about key differences, supporting the broader use of Level(s) in Norway as in Europe, and helping towards a harmonization of NS 3720 to Level(s).

Benefits of wooden structure reuse: the case of an Austrian building

The building sector is responsible for 39% of greenhouse gas (GHG) emissions; thus, it has a significant amount of potential to reduce the effects of climate change. Several active- and passive solutions and strategies have been developed and proposed in the literature. Among them, wood is highlighted as a promising solution to minimize GHG from buildings. However, the benefits, especially in the circular economy, are not fully evaluated due to methodological choices. Motivated by this knowledge gap, this article aims to evaluate the benefits of wood reuse compared to traditional building construction solutions. For this purpose, we have calculated the environmental impacts of a building situated in Graz, Austria. Four different scenarios are considered. The first scenario is a fully reinforced concrete building. The second scenario is a structural beam-column made from reinforced concrete with walls made of concrete blocks. The third scenario is a beam-column made from reinforced concrete with external walls based on clay blocks. Finally, the last scenario is a full wooden building. Following the standardized life cycle assessment (LCA) method, global warming potential (GWP) is calculated through a 0/0 approach. These evaluations were made possible by correlating the impacts released from producing wooden elements and the uptake of biogenic carbon from the forest. Without considering the possibility of material reuse, the wooden structure has a 5 % lower GWP value than the reinforced concrete building. Comparatively, the other building scenarios have almost similar impacts as the building in reinforced concrete. In the case of material reuse, the wooden structure building shows potential to develop projects with 44% lower environmental impacts.

Environmental and economic assessment of food additive production from mushroom bio-residues

This work analysed the environmental and economic impacts of extracts enriched in ergosterol and vitamin D 2 production from bio-residues of Agaricus Bisporus mushrooms. The main hotspots of the extractive processes in environmental terms were identified through the standardized methodology Life Cycle Assessment. In respect to the economic analysis, the Material Flow Cost Accounting approach was applied to identify production costs, distinguishing between valued and wasted costs. The LCA results showed that electricity consumption is a key factor in environmental aspects, having the highest contribution to the process's environmental impact. In general, the most electricity-consuming unit processes analysed were lyophilization, extraction and evaporation. Despite evaporation being a process with great energy consumption, it also mitigates environmental impacts, since it allows solvent recovery through the extraction and reutilization phases in new iterations. The production costs for the identified extracts were determined: extract enriched in ergosterol (2.43€/1 g of extract) and extract enriched in vitamin D 2 (8.28€/1 g of extract). Recovered solvent incorporation in posterior iterations resulted in a total cost decrease of about 47% for ergosterol-extract and about 39% for vitamin D 2 extract. Solvent's recovery and reutilization allowed to not only reduce the environmental impacts but also the production costs.

Life Cycle Assessments of Circular Economy in the Built Environment—A Scoping Review

The Circular Economy (CE) is gaining traction throughout all industries and nations globally. However, despite several attempts, no one-off solutions for assessing the benefits and pitfalls of CE have been established, and neither have any measures with which to determine decisions. In line with this general observation, the Built Environment (BE) is no different. A tendency is observed in which, for the assessment of the environmental impacts of CE, a Life Cycle Assessment (LCA) has been deemed suitable. This paper presents a scoping review, using the PRISMA statement extension for scoping reviews, documenting how LCA has been applied for assessment of CE in the BE. The review covers a broad scope of literature, scoping the landscape, and delimits it into publications where CE strategy has been defined explicitly and described as a CE investigation. Among the LCAs applied, the dominant system boundary choice is the attributional approach. The authors open the discussion on whether this is actually suitable for answering the questions posed in the CE paradigm. From the review, and the discussion, the conclusion suggests that there is no dominant procedure in applying LCA of CE in the BE, even despite commonly developed LCA standards for the BE. Few studies also present the consideration to reconsider the applied LCA, as CE puts new questions (and thereby a potentially greater system boundary, as CE may imply greater societal consequences) that do not necessarily fit into the linear LCA framework currently applied in the BE.