Life Cycle Assessment Method Research Articles

Life Cycle Assessment and Process Optimization of Precipitated Nanosilica—A Case Study in China

To mitigate environmental emissions in the industrial nanosilica sector and promote its sustainable development, the life cycle assessment (LCA) method is employed to evaluate the environmental impacts throughout the life cycle of industrial precipitated nanosilica. This LCA spans from the acquisition and transportation of raw materials to the production of nanosilica. By identifying the critical contributing factors, effective optimization strategies have been proposed to enhance the environmental performance of the nanosilica life cycle. The effects of electricity, alkalis, acids, and steam on the life cycle emission factors of nanosilica were examined. The results indicate that substituting traditional coal power and steam with cleaner alternatives like wind energy, hydroelectric power, and solar power (both photovoltaic and thermal), as well as biogas steam, can lead to a significant reduction in the life cycle emission factors of nanosilica, ranging from 50% to 90%. Notably, the types of acids and alkalis used only significantly reduce certain environmental factors. These findings provide valuable theoretical insights and practical guidance for the industrial nanosilica sector, particularly in the areas of energy conservation, emission reduction, and the transition towards a lower-carbon economy.

Quantification of Carbon Emissions of Building Decoration Processes

The continuous growth in building decoration activities has led to significant energy and material consumption, increasing carbon emissions in the construction sector. Existing literature frequently overlooks the carbon impact of building decorations. This study employs the life cycle assessment (LCA) method to quantify the carbon emissions associated with building decorations across five typic building types: residential, hospital, educational, sports cultural, and office buildings. Data were gathered using a mix of field investigations, document reviews, and semi-structured interviews, ensuring comprehensive coverage of all life cycle stages. The results reveal that carbon emission intensities of the studied building decorations ranged from 70.01 to 298.79 kg CO2 eq/m2, with the lowest emissions found in educational buildings and the highest in sports and cultural buildings. The decoration material production stage consistently emerges as the major contributor to emissions, accounting for over 50% of the life cycle of carbon emissions across all building types. The transportation stage also represents a significant share, contributing 18.6% to 24.5% across the building types. It also indicates that ceiling engineering as well as wall and column engineering are the primary carbon emission sources in terms of decoration activities. This study systematically compares the carbon emission characteristics of building decorations across multiple building types, addressing a gap that has been largely overlooked in the existing literature. It highlights the key sources of carbon emissions and proposes targeted mitigation strategies. The findings also suggest future research directions, including the application of innovative low-carbon materials, advanced construction technologies, and optimization of logistics. These insights lay a solid foundation for future low-carbon design and construction practices within the building sector.

Application of the Life Cycle Assessment (LCA) Method in Assessing the Environmental Impact of New Materials Derived from Waste Polymers in Terms of Sustainability

Sustainable socioeconomic development should provide humans with a suitable environment for safe living. It can be debated whether the term “environment” should be used due to the significant anthropogenic transformation of the environment. Therefore, an essential part of solving environmental problems is innovation. Climate, resource conservation, and environmental protection are recognized worldwide as common challenges. Thus, it is necessary to implement solutions that simultaneously protect the environment and the climate with sustainable and rational use of resources. Related to this issue is the principle of a loop/closed-loop economy. Among other things, it refers to using waste to prepare materials that can be used for other purposes. The use of tools such as LCA (life cycle analysis) contributes to supporting environmental protection. With the LCA method, it is possible to analyze environmental risks and compare new technological alternatives. LCA is a methodology that has been used around the world with great success, especially for studying individual stages of the entire product life cycle. The results of studies that have been conducted in various research centers confirm the possibility of also using the LCA technique for the environmental assessment of new technologies or existing modernized technological processes. The purpose of this study was to assess the feasibility of using the LCA method to determine the environmental impact that the potential production and use of new materials will have.

Potential, economic and ecological benefits of sweet sorghum bio-industry in China

BackgroundSweet sorghum (Sorghum bicolor) displays an excellent potential to serve as a non-food bioenergy feedstock for bioethanol production in China due to its high potential yield on marginal lands. However, few studies have been conducted on the potential of sweet sorghum yield and appropriate industrial models in different marginal regions in China. This study explored the spatial distribution of potential sweet sorghum production using the Decision Support System for Agrotechnology Transfer (DSSAT) model and proposed three typical industrial models of sweet sorghum industry to calculate their economic and ecological benefits.ResultsThe results indicate that considering the factors of land use, annual precipitation, soil salinity, soil pH, and accumulated temperature, approximately 32.23 million ha of marginal land are suitable for sweet sorghum cultivation in China, and 130 million tonnes (t) of ethanol can be produced. Further, the development of the sweet sorghum industry under the three models can generate 1425.49 billion CNY potential, approximately accounting for 3.57% of industrial added value in China if measured against 2023 levels, and reduce CO2 emissions by 4.68 million t.ConclusionsThis study provides an innovative perspective for the multi-industry large-scale promotion of sweet sorghum in different marginal lands based on the high spatial resolution Geographic Information System (GIS) data by the DSSAT model with a Life Cycle Assessment (LCA) method, and this applies not only to China but also to the worldwide and other types of energy plants.

A Review of Life Cycle Assessment Methods to Inform the Scale‐Up of Carbon Dioxide Removal Interventions

ABSTRACTLife Cycle Assessment (LCA) methods are increasingly used for policy decision‐making in the context of identifying and scaling up sustainable carbon dioxide removal (CDR) interventions. This article critically reviews CDR LCA case‐studies through three key lenses relevant to policy decision‐making on sustainable CDR scale‐up, namely comparability across CDR assessments, assessment of the climatic merit of a CDR intervention, and consideration of wider CDR co‐benefits and impacts. Our results show that while providing valuable life cycle understanding, current practices utilize diverse methods, usually attributional in nature, which are CDR and time‐specific. As a result, they do not allow comprehensive cross‐comparison between CDRs, nor reveal the potential consequences of scaling up CDRs in the future. We suggest CDR LCA design requires clearer definitions of the study scope and goal, the use of more consistent functional units, greater comprehensiveness in system boundaries, and explicit baseline definitions. This would allow for robust assessments, facilitating comparison with other CDR methods, and better evidencing net climate benefits. The inventory should collect time‐dependent data on the full CDR life cycle and baseline, and report background assumptions. The impact assessment phase should evidence the climatic merits, co‐benefits, and trade‐offs potentially caused by the expanding CDR. Finally, to ensure a sustainable scale‐up of CDR, consequential analyses should be performed, and interpretation involves the comparison of all selected metrics and the permanence of carbon storage against a baseline scenario.

Development and performance evaluation of ultra-lightweight geopolymer foam insulation material

The preparation technology for new ultra-lightweight geopolymer insulation materials (ULGIM) has been developed based on the principle of alkaline activation, and ULGIM for building walls have been obtained. It has improved the problem of traditional inorganic foam insulation material that cannot balance density, insulation performance, mechanical performance and environmental performance. The composition of supplementary cementitious materials, the mass ratio between each component, and water to binder ratio (w/b) were used to analyze the thermal conductivity, dry density, volumetric water absorption, compressive strength, average pore diameter, and porosity of ULGIM. The life cycle assessment (LCA) method was employed to assess the environmental impact of ULGIM production. The test results showed that ULGIM achieved a dry density and thermal conductivity of ULGIM only 181.17 kg/m3 and 0.0427 W/(m·K), respectively, and the optimal compressive strength was 0.72 MPa at 7 d. ULGIM exhibited superior compressive strength, lower thermal conductivity, and smaller environmental impact in comparison to cement-based foamed materials with comparable dry density.

Towards a sustainable thermodynamic optimization solution for preparing unburned low-carbon bricks from low-activity tailings

Basalt tailings, as an important type of solid waste in the mining industry and quarries, are mainly stacked in the open air or buried, causing huge potential harm to the environment and society. In this work, we propose a sustainable and promising utilization method for such low alkali activated tailings. A thermodynamic optimization solution and a design model for unburned low-carbon bricks composed entirely of solid waste were established, and the macro-microscopic mechanisms of hydrate formation and durability were comprehensively analyzed. Firstly, the thermodynamic reaction kinetics of the full chemical composition of basalt tailings modulated by fly ash were used to investigate the effects of different reaction material ratios on hydration products. Then, a new optimization design method of chemical thermodynamics model of alkali excitation was proposed. Further, the hydration mechanism of geopolymer was qualitatively and quantitatively analyzed via test of mechanics, XRD, FTIR, SEM and AFM. The calculation results were very consistent with experimental research, and the basalt-based fly ash-modulated geopolymer brick through optimization met the requirements of durability, especially from the viewpoint of excellent high-temperature resistance. Finally, the life cycle assessment (LCA) method was adopted to analyze the carbon emission reduction potential of current eco-friendly bricks. The carbon emissions were approximately 15.6 % of that of sintered shale hollow bricks and 19.4 % of that of aerated concrete building blocks. Thermodynamic optimization design of alkali activated low-activity tailings unburned bricks technology is one-stone-for-two-birds strategy, which can effectively optimize the process of making bricks from tailings.

Assessing the Environmental Impact of Municipal Waste on Energy Incineration Technology for Power Generation Using Life Cycle Assessment Methodology

The life cycle assessment methodology is a comprehensive environmental impact evaluation approach rooted in the “cradle-to-grave” concept. This study takes a municipal solid waste incineration power plant in central China as an example to comprehensively explore the potential ecological and environmental impacts of municipal solid waste incineration power generation through life cycle assessment methods. Burning one ton of waste can recover 7342 joules of thermal energy. Compared with traditional landfill, incineration can reduce greenhouse gas emissions by about 30%, with a potential global warming impact of −0.69 kg of carbon dioxide equivalent. Amongst environmental impacts, land, freshwater, and marine ecosystems possess the greatest potential toxicity, followed by the harmful effects on human health and the influence of ozone-producing photochemical pollution. Lastly, there comes terrestrial acidification, whereas other types of effects can be relatively disregarded in comparison. In the process of waste incineration power generation, the potential impacts of global warming, ionizing radiation, and fossil resource scarcity are less than zero, indicating that this is an environmentally friendly process. In response to the above-mentioned environmental impacts, it is necessary to pay attention to improving incineration efficiency, optimizing leachate treatment, reducing coal use, and controlling acidic gas emissions in the process of urban solid waste incineration power generation. This research offers insights into advancing environmentally sustainable technologies for utilizing waste as an energy resource.

Data quality assessment of aggregated LCI datasets: A case study on fossil‐based and bio‐based plastic food packaging

AbstractEnvironmental impacts resulting from plastic food packaging, made from both fossil‐based and bio‐based polymers, are increasingly analyzed in life cycle assessment (LCA) studies. However, the literature reveals significant variations in results for the same polymer within the same scope. To enhance the reliability of these assessments, data quality assessment (DQA) plays a relevant role. However, despite most of the LCA studies employing aggregated life cycle inventory (LCI) datasets, in the literature, DQA methods for aggregated processes are not available. To fill this gap, in this paper, a DQA for aggregated LCI datasets is proposed and demonstrated through its application to 101 aggregated LCI datasets, extracted from Ecoinvent and GaBi databases. The DQA method has been developed by adapting and integrating the pedigree matrix and the data quality ranking proposed by the recently published EC Plastic LCA method. The three data quality indicators (DQIs) used are technological, geographical, and time‐related representativeness. The application of this method exhibits an overall positive evaluation of the selected datasets with differences among the three DQIs. Moreover, it highlights the role of metadata structure in adequately supporting a robust DQA. Indeed, in the absence of a common framework that defines, assesses, and provides access to data quality information, transparency must be assured by the operator in the metadata interpretation and related assumptions along the DQA process. Finally, although the proposed DQA method was developed for the plastic sector, its application can be extended to LCI aggregated datasets relevant to other sectors, materials, and products.

Influence of Accelerated Carbonation on the Performance of Recycled Concrete Containing Fly Ash, Recycled Coarse Aggregate, and Fine Aggregate.

In order to improve the quality of solid waste utilization, this study simultaneously used recycled coarse aggregate and recycled fine aggregate to prepare recycled aggregate concrete, with fly ash partially replacing cement as a binder. After the particle gradation of recycled aggregate was artificially adjusted into continuous gradation, the effects of accelerated carbonation on the performance and microstructure of recycled concrete were studied. The microstructural change was analyzed using mercury intrusion porosimetry and scanning electron microscopy-energy dispersive spectroscopy. Additionally, the environmental benefits of the recycled concrete were evaluated based on carbon emissions using the life cycle assessment method. The experimental results indicate that accelerated carbonation can increase the compressive strength of recycled concrete by up to 13%, and its microstructure becomes more compact after carbonation. The carbon emissions are reduced by more than 13% after using 20% fly ash, contributing to sustainable development. Additionally, the optimal replacement rate of recycled fine aggregate should be controlled to under 15% when both recycled coarse and fine aggregates are used.

Environmental Sustainability Assessment of Cold Storage Panel Production

Today's ever-increasing environmental sustainability concerns have led to a major shift in construction sites and industrial sectors. In this context, the choice of construction materials for important structures such as cold storages plays an important role in terms of both environmental impacts and energy efficiency. The aim of this study is to evaluate the environmental loads of cold storage panels with thicknesses of 80 mm, 100 mm, 120 mm, 150 mm, 180 mm and 200 mm. In order to reveal the production inputs that cause these loads, the environmental effects were examined specifically for the 100 mm thick cold storage panel. Environmental impacts were analyzed using the Life Cycle Assessment (LCA) method in accordance with the ISO 14040/44 methodology as a system boundary "cradle to gate". This study focused on three different environmental impact categories of cold storage panels produced in Türkiye: global warming potential (GWP), cumulative energy demand (CED) and water footprint. In the evaluation of environmental impacts, production inventory information obtained from the panel manufacturer was used. For analyses, Simapro v. 8.5 LCA software was used. Analysis results show that the use of galvanized sheet metal in cold storage panel production is a hot spot in terms of global warming effect. It has been determined that the largest share in the water footprint belongs to polyurethane used as insulation material. Additionally, according to the CED, non-renewable fossil and non-renewable nuclear were determined to be the most affected categories, and the use of galvanized sheet metal and polyurethane were determined to be the most important hot spots in terms of non-renewable and renewable resources. To help improve the environmental performance of the cold storage panel, it is recommended to use bio-based and less environmentally impactful raw materials in production and to measure their environmental impact on a life cycle basis from cradle to grave.

Environmental impacts and nitrogen-carbon-energy nexus of vegetable production in subtropical plateau lake basins.

Vegetables are important economic crops globally, and their production has approximately doubled over the past 20 years. Globally, vegetables account for 13% of the harvested area but consume 25% of the fertilizer, leading to serious environmental impacts. However, the quantitative evaluation of vegetable production systems in subtropical plateau lake basins and the establishment of optimal management practices to further reduce environmental risks are still lacking. Using the life cycle assessment method, this study quantified the global warming, eutrophication, acidification, and energy depletion potential of vegetable production in a subtropical plateau lake basin in China based on data from 183 farmer surveys. Our results indicated that vegetable production in the study area, the Erhai Lake Basin, was high but came at a high environmental cost, mainly due to low fertilizer efficiency and high nutrient loss. Root vegetables have relatively high environmental costs due to the significant environmental impacts of fertilizer production, transportation, and application. A comprehensive analysis showed that the vegetable production in this region exhibited low economic and net ecosystem economic benefits, with ranges of 7.88-8.91 × 103 and 7.35-8.69 × 103 $ ha-1, respectively. Scenario analysis showed that adopting strategies that comprehensively consider soil, crop, and nutrient conditions for vegetable production can reduce environmental costs (with reductions in global warming potential (GWP), eutrophication potential (EP), acidification potential (AP), and energy depletion potential (EDP) by 10.6-28.2%, 65.1-73.5%, 64.5-71.9%, 47.8-70.4%, respectively) compared with the current practices of farmers. This study highlighted the importance of optimizing nutrient management in vegetable production based on farmers' practices, which can achieve more yield with less environmental impacts and thereby avoid the "trade-off" effect between productivity and environmental sustainability.

Waste rubber recycling in concrete-filled steel tube members: Mechanical performance, reliability and life cycle assessment

This paper focuses on the axial compression mechanical performance, reliability analysis and environmental impact of rubber concrete-filled circular steel tube (RuCFST) columns. Initially, the research of the axial compression performance reveals that enhancing the wall-thickness or yield strength of steel tubes variably increases the yield, peak, and ultimate loads of RuCFST columns. The degree of enhancement of each characteristic point by growing the wall thickness of the steel tube is 5 %–44 %, 6 %–44 %, and 9 %–44 %, respectively; while the degree of enforcement is 5 %–55 %, 23 %–53 %, and 24 %–61 %, respectively, upon yield strength increase. Reliability analysis indicates that higher concrete grades decrease the probability of axial compression failure in RuCFST columns. Raising the yield strength and wall-thickness of steel tubes leads to a reduction in the reliability index. Both larger and smaller live-to-dead load effect ratios adversely impact the reliability index. In addition, the life cycle assessment method was used to evaluate the environmental impact of RuCFST columns, and the analysis was made after considering the superposition effect of waste rubber incineration and recycling into rubber aggregates.

Biochar carbon removal from residues in Germany—assessment from environmental and economic perspectives

Abstract The topic of biochar carbon removal (BCR), which refers to the pyrolysis of biomass, is increasingly being discussed as a potential solution for the long-term removal of carbon dioxide from the atmosphere. However, BCR technology assessments in Germany, which are used as the basis for strategic decision-making, are often limited to woody biomass as an input material and are based on old data. Consequently, this study focuses on BCR from forest residues, straw and sewage sludge and assesses its contribution to negative emissions under current techno-economic framework conditions. Using life cycle assessment and annuity method, as well as complementary stakeholder engagement formats, the study provides a comprehensive analysis of BCR pathways in Germany based on an empirical, up-to-date data basis. The results highlight the environmental advantages of BCR, particularly in reducing greenhouse gas emissions compared to the conventional treatment of residues. The economic feasibility of BCR is uncertain, with profitability dependent on plant scale, biomass type and the integration of energy co-products. Stakeholder insights underscore the necessity for supportive policies and investment in BCR technology to enhance scalability. This interdisciplinary approach enriches the discourse on BCR’s role in achieving carbon neutrality and offers a robust data foundation for future evaluations.

A negative-carbon planning method for agricultural rural industrial park integrated energy system considering biomass energy and modern agricultural facilities

Biomass energy, recognized as a “zero-carbon” energy, has gradually become a crucial approach to promoting the low-carbon transformation of agricultural rural industrial parks (ARIP). Meanwhile, modern agricultural facilities (MAF) can play a significant role in adjusting agricultural load. Therefore, this paper proposes a negative-carbon planning method for the ARIP integrated energy system (IES). Firstly, carbon activities occurring during the operation of ARIP are sorted out and modeled based on the life cycle assessment (LCA) method, especially modeling the “zero-carbon” and “negative-carbon” benefits of biomass energy. At the same time, the models of both agricultural irrigation systems and straw bundling direct combustion heating are constructed in the ARIP planning. Then, a negative-carbon planning model for ARIP IES is established with the goal of minimizing the annualized total cost, where carbon emission reduction is integrated into the optimization objectives through carbon trading. On this basis, a two-stage distributionally robust optimization (DRO) planning model is constructed, where a box-like set and comprehensive norm constraints are used to model the seasonal differences of agricultural industry loads and the uncertainty of probability distribution in photovoltaic (PV) scenarios. Especially, a box set with adjustable uncertainty coefficients is introduced to simulate fluctuations of output in PV scenario. Finally, the CPLEX solver is used to solve the planning model. verify the effectiveness of the proposed planning method in enhancing the economic and environmental effects of ARIP. Results indicate that the proposed planning model can reduce the total cost by 49.584 × 104 $. Besides, the annual carbon emissions can be reduced from 37533.98 t CO2-eq to −15834.5 t CO2-eq. Especially, the carbon sequestration effect of biochar is the key link in achieving “negative carbon” in ARIP.

Optimal Capacity Allocation for Life Cycle Multiobjective Integrated Energy Systems Considering Capacity Tariffs and Eco-Indicator 99

Traditional energy systems pose a significant threat to human social development due to fossil fuel depletion and environmental pollution. Integrated energy systems (IESs) are widely studied and applied due to their clean and low-carbon characteristics to achieve sustainable development. However, as integrated energy systems expand, their impact on ecosystems becomes more pronounced. This paper introduces the concept of the ecological damage index (EDI) to promote the sustainable development of integrated energy systems. Moreover, the introduction of a capacity tariff mechanism will impact the energy structure, making it essential to consider its effects on capacity allocation within integrated energy systems. This paper proposes a multiobjective optimization framework for constructing a capacity planning model for integrated energy systems, focusing on achieving a multidimensional balance between the economy, environment, and ecosystem using the life cycle assessment (LCA) method. Finally, the nondominated sorting genetic algorithm-II (NSGA-II) is employed to optimize the three objectives and obtain the Pareto frontier solution set. The optimal solution is selected from the solution set by combining the technique for order preference by similarity to ideal solution (TOPSIS) and Shannon entropy method. In comparison to scenarios with incomplete considerations, the multiobjective capacity optimization model proposed in this study exhibits significant improvements across the three metrics of cost, carbon emissions, and the ecological damage index, with a 19.05% reduction in costs, a 26.24% decrease in carbon emissions, and an 8.85% decrease in the ecological damage index. The study demonstrates that the model abandons traditional single-objective research methods by incorporating a multidimensional balance of the economy, environment, and ecosystems. This approach forms a foundational basis for selecting the optimal energy mix and achieving sustainable development in integrated energy systems. The life cycle assessment methodology evaluates impacts across all stages of integrated energy systems, providing a comprehensive basis for assessing and planning the sustainable development of the systems. The study offers guidance for the rational allocation of the integrated energy system capacity and advances the sustainable development of such systems.

Environmental, economic, and eco-efficiency assessment of residential heating systems for low-rise buildings

Transitioning from fossil fuels to renewable heating is essential for rapidly reducing greenhouse gas emissions. Besides greenhouse gas emissions, other environmental and economic impacts are crucial for successfully implementing renewable heating systems. This study evaluates 13 residential heating systems' environmental, economic, and eco-efficiency performance for a typical German two-story dwelling. The life cycle assessment method is employed to quantify the environmental impacts. Assuming a sustainable supply of biomass-based fuels, biomass heating systems exhibit the lowest environmental impacts, whereas gas heating systems are associated with high environmental impacts. Among heat pump systems, the water-source heat pump demonstrates the lowest environmental impact. Additionally, integrating a PV system into heat pump systems reduces the environmental impacts across all heat pumps. The evaluation indicates that the air-source heat pump is the most economical system, while the pellet boiler with solar thermal support and the heat pump with ice storage incur the highest costs. However, the cost differences among the heating systems are relatively small, making it challenging to establish a clear ranking based solely on economic evaluation. An eco-efficiency assessment, which combines environmental and economic aspects into a single indicator, reveals that the most eco-efficient systems are the air-source heat pump, both with and without a PV system, and the wood gasifier heating system. In contrast, the ice-storage heat pump and the pellet heating with solar thermal support show the lowest eco-efficiency.

Carbon footprint impact of waste sorting on the municipal household waste treatment system: A community case study of Hangzhou

Considering the pressing need to reduce carbon emissions, the environmental impacts of waste sorting and its influencing factors remain unverified across many practical scenarios. This study focused on separating perishable and residual waste in a community in Hangzhou, China, examining how waste sorting behavior affects the carbon footprint of subsequent waste treatment systems through a randomized tracking survey and life cycle assessment (LCA) method. The results indicated that the sorted waste treatment system could achieve net carbon emissions ranging from −139.92 to −254.03 kg CO2 eq per day by integrating the anaerobic digestion of sorted perishable waste with the incineration of residual waste. In comparison to the conventional mixed incineration system, which had net carbon emissions between −56.37 and −115.46 kg CO2 eq per day and generated 383 kWh/t of power, the carbon reduction benefits of the sorted system were considerably greater, by a factor of 2.2–2.5. Additionally, the average amount of recovered electrical energy (993 kWh/t) was also higher by a factor of 2.6. Therefore, source separation of waste significantly enhances energy recovery and carbon reduction in household waste treatment systems. In this research system, incineration power generation and oil recovery serve as the primary units for reducing carbon emissions, and the proportion of residual waste generated greatly influences the total carbon emissions of the sorted waste treatment system (p < 0.05). Consequently, increasing the percentage of classified residual waste and optimizing machine efficiency will increase the carbon reduction benefits of waste sorting and treatment systems. These findings provide crucial references and guidance for advancing carbon reduction and waste classification in municipal solid waste (MSW) management systems.

Demountable structures: evaluation of a circular design approach through life cycle assessment

Abstract The demand to reduce the use of raw materials, construction waste, and the negative environmental impacts of the construction sector is constantly increasing. New circular design strategies, such as Design for Disassembly, are intended to meet these challenges. Furthermore, circular strategies facilitate the easy and quick replacement of building components during end-of-life phases, as well as the efficient and waste-free deconstruction of entire buildings for subsequent reuse. However, building structures developed according to these strategies can have a higher environmental burden in the production or use phase of their life cycle. To confirm the actual environmental benefits of circular constructions, the paper utilizes the Life Cycle Assessment (LCA) method as a vital tool for the environmental evaluation of circular structures. As a case study, fully demountable and conventional masonry building façade systems with insulation are analyzed through a cradle-to-cradle approach over 2 life cycles. Several End-of-Life scenarios, as well as reuse and the benefits it provides, were considered during the assessment. Examining eight environmental indicators, the comparative analysis of linear and circular facade design approaches in the chosen case studies provides insights into efficient and environmentally friendly solutions.

Environmental Impact Assessment of a Plant Cell-Based Bio-Manufacturing Process for Producing Plant Natural Product Ingredients

Purpose: This study employed a Life Cycle Assessment (LCA) methodology to evaluate the environmental impacts of a novel plant cell-based biomanufacturing process for producing plant natural product ingredients. The primary purpose was to assess the relative sustainability of the process and to provide insights into potential areas of improvement in the biomanufacturing process. Method: The LCA method used an MS Excel (Ver. 2407) -based approach with a cradle-to-gate system boundary covering raw material sourcing (A1), raw material transportation (A2), and product extract manufacturing (A3) stages. Energy use and material inventory data are presented for different unit operations, and environmental impact factors were obtained from the Ecoinvent database. The study included a Material Circularity Index (MCI) calculation to assess the circularity of the biomanufacturing process for the production of saponin emulsifiers that are normally extracted from the woody tissue of the Chilean soapbark tree (Quillaja saponaria). Comparative analyses were performed against a wild-harvest approach for plant tannin extraction from spruce (Picea abies) tree bark. Key Results: The environmental impact assessment focused on determining relative Global Warming Potential (GWP), Acidification Potential (AP), Freshwater Eutrophication (FE), Particulate Matter Formation (PMF), and Ozone Depletion Potential (ODP). Results indicated that the extract manufacturing stage (A3) contributed significantly to adverse environmental impacts, with varying levels of effects based on the energy source used. Comparative analysis with the wild harvest approach highlights the lower environmental impact of the alternative biomanufacturing process. The biomanufacturing process showed a 23% reduction in GWP, AP, and FE and a 25% reduction in PMF and ODP relative to the wild harvest approach. However, the MCI for the biomanufacturing process was estimated to be 0.186, indicating a low material circularity. Conclusions: The results revealed that the extract manufacturing stage, particularly energy consumption, significantly influences the relative environmental impacts of the alternative production processes. Different energy sources exhibit varying effects, with renewable energy sources showing lower environmental impacts. The Material Circularity Index indicated a low circularity for the biomanufacturing process, suggesting opportunities for improvement, such as incorporating recycled or reused materials. Compared with the tannin extraction process, the plant cell-based biomanufacturing process demonstrated lower environmental impacts, emphasising the importance of sustainable practices and the use of renewable energy sources in future plant natural product sourcing. Recommendations include implementing more sustainable practices, optimising raw material choices, and extending product life spans to enhance circularity and overall environmental benefits.