Life Cycle Assessment Results Research Articles

Sustainable Production Insight Through LCA and LCC Analysis of Injection Overmolded Structural Electronics Manufactured through Roll-to-Roll Processes.

Printed electronics (PE) have provided new material and application opportunities for devices and systems as well as new manufacturing routes that all need to be considered for commercialization. This paper introduces a case study with universally relevant manufacturing processes and applications in the PE area, focusing on the Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) of the Personal Activity Monitor (PAM) device. In the study, the PAM device's most important costs and environmental impacts during the prototype pilot production and device use phases are identified and assessed. Additionally, the potential environmental impacts of post-consumption scenarios are considered. The LCA results indicate that the roll-to-roll (R2R) assembly of electronics and the R2R injection over-molding are generally the most prominent production process steps affecting the results. From the LCC perspective, the capitial expenditure (CAPEX) contributor is the R2R assembly pilot line, due to its high investment cost and long operating time compare to other production assets. The traditional electronic components are the major operating expenditures (OPEX), especially the microcontroller units (MCUs) and accelerometers, in contrast to the low impact from the printed electronics. There are several advantages to applying LCA and LCC since they provide explanations of the relationships between cost, environmental, design, and manufacturing characteristics.

Life Cycle Environmental and Economic Assessment of Different Biogas and Biogas Residue Operation Models

The utilization of biogas and biogas residues is an important objective of animal manure resource management. Regarding the environmental friendliness and economic suitability of utilization modes, previous studies have evaluated and compared biogas or biogas residue individually, which may lead to incomplete environmental and economic assessments. In this study, the environmental and economic aspects of six integrated biogas and digestate operation modes, i.e., biogas utilization (direct combustion, cogeneration, and purification) and biogas residue utilization (field return and composting), were analyzed via life cycle assessment (LCA) and the net present value (NPV) method, with an animal manure biogas plant in Tangshan City as the study object. The results of LCA showed that biogas cogeneration + biogas residue composting disposal was superior to other models in most environmental indicators. NPV analysis showed that direct biogas combustion + biogas residue composting was the best, breaking even in the 3rd year with a cumulative profit of 250 million CNY. With increased environmental costs and benefits, the biogas cogeneration + biogas residue composting model had the best performance in terms of efficiency ratio at 2.58; the NPV of both operating models of biogas cogeneration increased, while the NPV of the other operating models decreased about 20%.

Carbon Accounting and Carbon Emission Reduction Potential Analysis of Sponge Cities Based on Life Cycle Assessment

In recent years, China has been vigorously carrying out the construction and development of a sponge city. To prove that the material and energy consumption involved in the implementation of a sponge city is much less than that of the integrated urban drainage system (IUDS) in addition to saved energy and reduced carbon in the sponge city, it was important to calculate the corresponding carbon source and sink and analyze its key influence factors. The emission factor method was used to calculate carbon emissions. In view of this, based on the Intergovernmental Panel on Climate Change (IPCC) guidelines and life cycle assessment (LCA), this research established a systematic accounting method for carbon emissions from the IUDS and the sponge city, which focused on improving the calculation method of the carbon sink stage. A case study was conducted in Beijing, China, and the carbon emission reduction effect of the construction of the sponge city was discussed. The results showed that the carbon emission reduction potential (CRP) of sponge facilities in this project for 50 years was 612.45 tons of CO2 equivalent after the renovation. Compared with IUDS, sponge city construction had a positive effect on carbon emission reduction and reduced carbon emissions by 87.08% on average. For the IUDS and the sponge city, the stormwater pipe network had the largest contribution of carbon emission, and its material, transportation, pipeline laying, and maintenance of stormwater pipe networks had important influences. Morris global analysis method was used to analyze the sensitivity of LCA results and obtained that the influence degree of sensitivity factors on carbon emissions in the life cycle was in the order of annual rainfall > carbon sequestration rate of green space > high-density polyethylene (HDPE) > transport distance > fertilization and insecticide. This study can provide a positive contribution to the construction of a sponge city and planning the low-carbon development of the city in the future in China.

The impact of passenger electric vehicles on carbon reduction and environmental impact under the 2050 net zero policy in Taiwan

In response to the 2050 net-zero emission goal, Taiwan initiated the “Pathway to Net-Zero Emissions” in 2022, including a focus on electric vehicles (EVs). However, the emission reduction effect of electric vehicles has not been fully studied in Taiwan. Therefore, this study aims to conduct life cycle assessment (LCA) on environmental performance by replacing petrol vehicles with electric vehicles on the basis of the well-to-wheel method. This study also establishes a feedback mechanism through system dynamics to correlate the DALY results of LCA with population and energy demand. Results of the impact of DALY on lifespan and population is relatively small, indicating that the reduction in environmental impact from electric vehicles helps mitigate the decline in population. The emission-reducing potential and environmental impact of electric vehicles by 2050 are also estimated. Results demonstrate that within a 95% confidence interval and considering uncertainties arising from total driving distance, fuel economy, and energy intensity of electric vehicles, the greenhouse gas emissions of electric vehicles in 2050 will be between 7.826 × 105 and 1.069 × 106 tCO2e, respectively. In addition, the emission-reducing potential of electric vehicles is in the range of 1.076 × 106 to 1.804 × 106 tCO2e.

Influence of BIM's level of detail on the environmental impact of buildings: Danish context

Integrating a BIM-based life-cycle assessment (LCA) in the early design stages of building projects can promote a reduction of environmental impacts. However, the reliability of the analysis depends on the quality of the model. BIM modelling of timber-frame construction is often simplified, potentially hindering the LCA outcome due to quantity inaccuracy and a failure to consider elements regarded as negligible. This study addresses the methodological problem that influences the calculation of the environmental impact by examining the various environmental impacts caused by inventory data obtained from BIM models with a level of detail of (LOD)350–400 vs LOD200. The environmental impacts obtained from both models of a timber building calculated through an attributional LCA method are compared. Material inventory sourced from the LOD200 model results in a 14.7% lower value of embodied impact. The discrepancies resulted from aluminium, mineral wool and bitumen, which are identified as critical materials requiring quantity adjustment. Relying on simplified BIM models for LCA may lead to the GWP being under-estimated with incorrect identification of hotspots in the early design stages. The results aksi question the cut-off criterion of the current EN15978 norm that serves as a foundation for developing environmental policies within the industry. It recommends exclusion of materials constituting less than 1% of the overall mass from the system boundary. This study underscores the potential significance of materials falling below this threshold, challenging the validity of the criterion, and suggesting that such materials should be carefully evaluated and included in the LCA to ensure a comprehensive assessment of the environmental impacts. The overall objective of the study is to emphasize the importance of employing accurate BIM models in LCAs to make informed decisions that are aligned with the sustainability goals, encouraging practitioners to consider the impact of critical materials, even those with seemingly minimal contributions. With this knowledge, the practitioners are able to take meaningful actions that compensate for the LCA uncertainty, mitigating the environmental burden of the most impactful areas. Most importantly, the findings aim to identify the error in design LCA versus as-built studies, helping to develop design LCA tools that predict the as-built impact more precisely and earlier in the design process. The findings can also improve the expected building model definition in carbon policies.

A sustainable alternative? A comparative life cycle assessment of epoxy adhesives

AbstractIn response to the imperative of eco‐friendly material substitution, a comparative cradle‐to‐gate life cycle assessment (LCA) of two epoxy adhesives is presented: a traditional epoxy resin and an innovative self‐curing epoxy derived by epoxidizing poly‐beta‐myrcene (a constituent of Chios Mastic natural resin). Employing ReCiPe 2016 indicators and standard normalization, our study reveals that epoxidized poly‐beta‐myrcene outperforms conventional epoxy in 9 of 18 assessed midpoint indicators, with minimal impact in 7, and marginally higher impact in 2. The superiority of epoxidized poly‐beta‐myrcene extends to all three ReCiPe Endpoint protection areas. Atom economy and the E‐factor are also considered and related to the LCA results. Furthermore, the evaluation demonstrates epoxidized poly‐beta‐myrcene's remarkable environmental favorability compared to a literature bio‐based epoxy across multiple CML‐IA‐baseline indicators. In summary, epoxidized poly‐beta‐myrcene emerges as a promising, ecologically sensitive alternative to current conventional and bio‐based epoxy options.

Life cycle assessment of AnMBR technology for urban wastewater treatment: A case study based on a demo-scale AnMBR system

This study aims at assessing the environmental performance of a projected full-scale anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) at ambient temperature. To this aim, data from an AnMBR demonstration plant equipped with commercially available equipment, including industrial hollow fiber and degassing membranes, was used for projecting a full-scale facility. The use of real operation data allows to obtain robust results that contribute to improve the knowledge of the environmental performance of this technology, pointing out its strengths and the challenges that still need to be addressed. Life cycle assessment (LCA) was applied by means of Ecoinvent data base and ReCiPe2016 methodology considering 1 kg of removed COD as functional unit. Additionally, sensitivity and uncertainty analysis were conducted. Energy balance showed AnMBR performing as energy producer (net energy surplus up to −0.688 kWh·kg CODrem−1) and carbon sink (emissions credit up to 0.223 kgCO2eq·kgCODrem−1). Results also showed energy recovery, heavy metals in sludge, dissolved methane in the effluent, and effluent nutrient content as the most important aspects affecting LCA outcome. Construction phase affected some impact categories significantly (e.g., 51–71% in mineral resource scarcity, 18–27% in fossil resource scarcity, 21–28% in water consumption), therefore its exclusion should be carefully evaluated. CHP efficiency, dissolved methane recovery, filtration productivity, membrane scouring, reactor mixing, HRT and SRT appeared most influencing parameters. Finally, actions leading to increase the recovery and valorization of dissolved methane and/or of nutrients through, for instance, fertigation, improve the environmental performance of AnMBR for UWW treatment.

Study on the Life Cycle Assessment of Automotive Power Batteries Considering Multi-Cycle Utilization

This article utilizes the research method of the Life Cycle Assessment (LCA) to scrutinize Lithium Iron Phosphate (LFP) batteries and Ternary Lithium (NCM) batteries. It develops life cycle models representing the material, energy, and emission flows for power batteries, exploring the environmental impact and energy efficiency throughout the life cycles of these batteries. The life cycle assessment results of different power battery recycling process scenarios are compared and analyzed. This study focuses on retired LFP batteries to assess the environmental and energy efficiency during the cascade utilization stage, based on a 50% Single-Cell Conversion Rate (CCR). The findings of the research reveal that, in terms of resource depletion and environmental emission potential, LFP batteries exhibit lower impacts compared to NCM batteries. The use of hydrometallurgy in recovering LFP power batteries leads to minimal life cycle resource consumption and environmental emission potential. During the cascade utilization stage of LFP batteries, significant benefits are noted, including a 76% reduction in mineral resource depletion (ADP e) and an 83% reduction in fossil energy depletion (ADP f), alongside notable reductions in various environmental impact factors. Simultaneously, considering the sensitivity of life cycle assessment indicators and their benefit percentages to different CCRs, it is observed that ODP exhibits the highest sensitivity to CCR changes, while evaluation indicators such as HTP, AP, and GWP show relatively lower sensitivity. This study can provide an effective reference for the establishment of an energy saving and emission reduction evaluation system of power batteries.

Effect of realistically estimated building lifespan on life cycle assessment: A case study in Korea

In the construction industry, estimating the realistic lifespan of buildings is essential to properly perform life cycle assessments (LCAs). It is impractical to consider all of the different factors affecting building lifespan; therefore, most LCAs assume a standard building lifespan for each major type of building structure. However, the lifespans of buildings vary significantly in practice, and applying a uniform lifespan to all buildings with the same structural type may lead to completely erroneous LCA results. In this study, LCAs of waterproofing methods on building models and actual buildings in Korea are used to empirically demonstrate the effect of realistic lifespan prediction using big data. Applying a more representative building lifespan of 5–39 years in the waterproofing LCAs of an architectural model decreased the carbon emissions in all phases (construction, operation and maintenance, and demolition) by 78–24%, respectively, relative to a 50-year lifespan assumption. During the maintenance phase, the reductions were 100–31%, respectively. The accuracy of the waterproofing LCAs of 17 real buildings became more irregular as the percentage error of the predicted lifespan increased, although the LCA analysis results had 0% error for buildings with a predicted lifespan error of 6% or less. Therefore, depending on the research purpose, a low-error predictive building lifespan model can evidently support accurate LCA results. This study proves that the use of a big data-based building lifespan prediction method is essential for LCA and is an effective tool for business planning and critical decision-making throughout the construction process.

Environmental and economic analysis of sector-coupling battery energy storage systems used for frequency containment reserve

Battery energy storage systems (BESSs) are advocated as crucial elements for ensuring grid stability in times of increasing infeed of intermittent renewable energy sources (RES) and are therefore paving the way for more sustainable energy systems. Providing frequency containment reserve (FCR) is an attractive business model for capital intensive stationary BESSs, but the current German FCR regulative framework restricts the BESS usage for other applications as capacity shares have to be reserved (FCR energy capacity requirement). Hence, stationary BESSs operating at the FCR market are not fully utilised from an economic and environmental perspective. Linking BESSs with other sectors as potential sinks such as power-to-heat modules or electrolysers, enables unlimited energy infeed and is discussed as potential means to diminish this constraint. Whilst, a couple of studies investigated the economic advantages of such sector-coupling BESSs, their environmental consequences were hardly analysed so far. Based on the life cycle thinking approach, the environmental and economic impacts of FCR provision in Germany by standalone and sector-coupling BESSs (i.e. with power-to-heat unit or electrolyser) were studied in this work. The sector-coupling BESSs were considered regarding different FCR energy capacity requirements (E/P ratios). It was shown that the CAPEX for the sector-coupling unit were primarily critical for the economic performance of BESSs favouring power-to-heat over electrolysers and standalone BESSs. The results of the environmental life cycle assessment indicated to potential benefits due to the reduced battery capacities depending on the varied FCR energy capacity requirement. The environmental implications of the operational stage showed that electrolysers can increase the environmental impacts by up to 10 % due to higher conversion losses compared to power-to-heat units. Finally, it was concluded that future energy system and market designs should foster the implementation of sustainable sector-coupling solutions considering technology-specific economic and environmental characteristics.

Green Synthesis of Reticular Materials

AbstractTo help ensure a prosperous future on Earth for coming generations, academia and industry need to transform the way they plan and carry out the synthesis of novel materials to make them more environmentally sustainable. In particular, the field of reticular materials, i.e., metal‐organic frameworks, zeolitic imidazolate frameworks, and covalent organic frameworks, has great potential to outperform other materials and revolutionize various fields of applications. This review highlights several key aspects from the choice of their starting materials, solvents and synthetic methodologies that fall under the umbrella of the Green Chemistry principles, and incorporates a Circular Economy perspective by providing relevant strategies such as reuse, regeneration, or recycling to maximize the value of the Earth's available resources. Moreover, it will shed light on the life cycle assessment results of selected reticular materials and consider how constraints imposed by Green Chemistry principles, life cycle assessment metrics, and circular patterns will shape the future rational sustainable design and discovery of reticular materials.

Fluid Flow in the Gas Diffusion Layer Using Computational Fluid Dynamics and Microscopy Techniques

The utilization of a proton exchange membrane fuel cell (PEMFC) as an energy provider using hydrogen as a fuel has increased drastically. The reasons are the current limitation of fossil fuel-based devices, pollutants-free, high efficiency, and zero-carbon emission. The life-cycle assessment results of this type of fuel cell have also indicated the lowest contribution to global warming, human health, and resource scarcity in comparison to other types of fuel cells. In this regard, improving the performance of PEMFC is of importance.As an important component of the PEMFC, the gas diffusion layer (GDL) transports the gas reactants to the catalyst layer with the least electrical resistance. The GDL is often made of carbon fibers and should have a surface with good electrical contact and hydrophobic properties to facilitate the water removal. Remaining water in the GDL will result in difficulties during the cold-start and enhances the degradation of this layer. It is believed that the water removal of the GDL has a direct relationship with the capillary pressure, which is strongly linked to the GDL’s microstructure and wettability. However, further investigations can be done once a comprehensive simulation model is developed to monitor the changes in the GDL liquid removal by the effective parameters.In this regard, the Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) has been used to perform three-dimensional cross-section imaging of the GDL. The GDL samples are provided by Freudenberg in which the Microporous layer (MPL) is impregnated into the GDL. The average porosity of this sample is in the range of 75% while having the in-plane gas permeability of 2.4 under a compressive stress of 1 MPa. The utilized resin for FIB-SEM imaging is a mixture of Epoxy embedding medium (diglycidyl ether of bisphenol – A) with two different hardeners DDSA (2-Dodecenylsuccinic anhydride) and MNA (Methylnadic anhydride), which will be mixed with DPM – 30 [2,4,6 – Tris(dimethylaminomethyl)phenol] as the accelerator, all provided by Sigma Aldrich. After the preparation of the resin, 0.4 gr of Cobalt (II) acetylacetonate nanoparticles (supported by Sigma Aldrich) were added to 7.14 ml of the resin to improve the contrast of the images. The samples were impregnated with the resin under vacuum to be pressurized (3 MPa) for 20 minutes, and afterward, heated in an oven at 60℃ for 12 hours. The surfaces for analyses were cut by a diamond wire, polished by abrasive plates down to 0.1 and gold coated (20nm).FIB-SEM acquisition consisted of the polishing of cross-sections with a focused ion beam (LMIS Ga+ source) at 30 keV and 1 nA (Zeiss Crossbeam 540), followed by imaging with an electron beam at acceleration voltages of 1.0, 3.0 kV. Milling and imaging were performed at a working distance of 5.2 mm and stage tilt of 54°, i.e., the coincidence point of the electron and ion beams.Once the three-dimensional cross-sections of the GDL are obtained, the segmentation and reconstruction will be made to provide the needed geometry for fluid flow simulation and to calculate the microstructural properties. Fig. 1 shows the generated structure of the GDL after the segmentation and reconstruction of the cross-section images. The geometry will be then used to characterize the effective parameters of the thermal/water management of the PEMFC. This study can also be a valid reference for future computational fluid dynamic analyses in the GDL using the numerical modeling with the conservative equations or the Lattice Boltzmann modeling (LBM) with the kinetic and particle distribution equations. Keywords : Proton exchange membrane fuel cell (PEMFC); Gas Diffusion Layer (GDL); Focused Ion Beam- Scanning Electron Microscopy (FIB-SEM); Three-dimensional simulation; Lattice Boltzmann method (LBM) Figure 1

Impact of Drinking Water Treatment Process Using Life Cycle Assessment (LCA) to Minimize Environmental Impact Risk

The clean water treatment plant at DWTP is carried out with conventional treatment. The conventional water treatment process has an impact on the environment due to the clean water treatment process. Clean water treatment produces GWP and Eutrophication impacts derived from the use of chemicals and electricity. This study aims to analyze the factors causing environmental impacts arising from the clean water treatment process at the PDAM Water Treatment Plant (IPA) and determine policy priorities related to reducing environmental impacts and improving the quality of drinking water treatment at the Water Treatment Plant based on the results of LCA and AHP studies. The Life Cycle Assessment (LCA) method is a method of assessing the potential environmental impact and evaluating the environmental performance of a process on the product. Life Cycle Assessment (LCA) consists of four stages, namely determination of Goal and Scope, Life Cycle Inventory, Life Cycle Impact Assessment, and data interpretation. In research, the scope of LCA used is Gate to Gate, namely in the Coagulation, Flocculation, and Sedimentation process units. From the results of the LCA study, the potential impact of GWP of 12760.76 KgCO2-eq comes from flocculation which produces floc from the addition of chemicals. Meanwhile, the potential impact of eutrophication is 268.55 KgPO4-eq derived from mud generation. The results of the decision in reducing environmental impact at DWTP by optimizing chemicals as a top priority, then the second priority by recycling sludge, and finally making savings and energy alternatives are the last priority. Each respondent's score reached 55%, 23% and 22%. The results of the implementation of the program if implemented can reduce the impact of GWP 20079.17 kg CO2-eq and the impact of eutrophication can be reduced by 201.401 kg PO4-eq.mportant matters discussed in the paper that significantly contribute to the final result of the research may be noted here, but you have to consider, however, the limited space of the abstract.

Establishing the effectiveness of life cycle assessment to assess the environmental impact of passenger cars using biofuels: A Review

Predictions and decisions made by legislators may be partially or wholly informed by the results of life cycle assessment studies, but the outcomes can vary significantly. This review seeks to establish whether existing life cycle assessment study results are accurate and if there are errors or deficiencies in life cycle inventory databases, chosen methodologies, or choice of life cycle assessment tool that may impact the outcome of life cycle assessment studies. The context of the work is set against the role bioethanol/gasoline blends might play in reducing the environmental impact of internal combustion engine-powered vehicles. The findings indicate inaccuracies exist and that there are various reasons for this. The accuracy of life cycle assessment results is affected by differences and inconsistencies that occur between life cycle inventory databases, the choice of life cycle inventory databases and life cycle assessment tools and because, in many cases, life cycle assessment methodology does not specify whether the biofuel content in the fuel is considered. The increase in the average age of biofuel-compatible passenger cars challenges the validity of results obtained by employing the commonly used approach based on fixed annual mileage profiles and lifetime activity. Uncertainty is a significant factor, and more attention should be paid to uncertainty analysis. Evidence shows the use of biofuels can deliver considerable environmental gains and reductions in CO2, especially in blends containing a higher percentage of biofuel.

Assessing the economic and environmental impacts of battery leasing and selling models for electric vehicle fleets: A study on customer and company implications

Battery electric vehicles (BEVs) powered by renewable energy hold promise for significantly decarbonizing land-based transport. However, the environmental impacts of BEVs remain a critical concern. This paper investigates the circular business model (CBM) of leasing batteries for BEVs and compares its economic and environmental impacts with the linear model of selling and buying batteries. A comprehensive approach combining a battery fleet model, net present value (NPV) analysis, and cradle-to-grave life cycle assessment (LCA) is employed. By considering diverse driving profiles instead of the single “average” profile used in previous studies, the battery fleet model provides a more accurate representation of reality. The findings reveal that while leasing batteries can be as profitable as selling them, companies that lease may require higher revenues and tax contributions to obtain a comparable NPV. To generate additional income, companies may need to charge fees that do not always benefit customers. Notably, battery purchasing remains the most cost-effective option for users driving over 10,000 km/year. The LCA results indicate that the environmental benefits of leasing batteries over selling them are marginal. Leasing offers advantages such as user flexibility, and it encourages battery repair, repurposing, and recycling; however, there is insufficient evidence to support the cost-effectiveness of leasing or significant environmental improvements over traditional buying and selling models. The findings may be relevant for other business models targeting a substantial user base in the BEV domain, such as battery-as-a-service (BaaS) programs and battery swapping.

Precision nitrogen management in rainfed durum wheat cultivation: exploring synergies and trade-offs via energy analysis, life cycle assessment, and monetization

Fertilization with variable rate technology (VRT) is a pivotal technique of precision agriculture proposed for eco-friendly farming practices. Yet the magnitude of environmental benefits is often not well known or is highly variable. This study used a multi-indicator model and life cycle-based indicators to compare the performance of rain-fed durum wheat production using uniform (UA) and variable N fertilization (VRT). Two functional units were used: 1 ha of cultivated wheat and 1 ton of wheat produced. The energy analysis indicated that VRT increases energy use efficiency and productivity by 13.3%, reduces specific energy and total energy input by 11.7%, and increases net energy gain by 15.3%. The life cycle assessment (LCA) analysis indicated that for some environmental impacts, VRT had minor negative effects due to the comparable yield performance with UA. Yet, the VRT had a noteworthy positive impact on global warming, fine particulate matter formation, stratospheric ozone depletion, terrestrial acidification, and marine eutrophication, generating a final environmental benefit of 12.2% for 1 ton of product and 13.3% for 1 ha of land. Economic valuation or monetization of LCA results using monetization weighting factors indicated indirect economic benefits of VRT can be up to 6.6% for 1 ton of product and 7.7% for 1 ha of land. Our findings support the use of nitrogen fertilization with VRT for sustainable extensification and improved eco-efficiency of wheat production in a Mediterranean context. As a result of our research, we conclude that future case studies on annual crops with moderate land requirements should employ multiple metrics and functional units, as well as the concepts of monetization and life cycle assessment, to investigate trade-offs between yield, economic, and environmental benefits and to aid decision-making about the true sustainability of proposed farming technologies.Graphical abstract

A low carbon embedded low water/binder cement-based composites (LW/BCC) based on steel slag powder and microwave pre-curing: Experiments and Life Cycle Assessment (LCA)

This paper proposes a new design and preparation method for low carbon embedded low water/binder cement-based composites (LCE-LW/BCC), including experimental investigation and Life Cycle Assessment (LCA). To be specific, a recycled steel slag powder (SSP) is utilized to replace the cementitious material with high CO2 emission in normal LW/BCC, while an effective microwave pre-curing is employed to treat the developed samples at early age. After that, to determine the optimal parameters of microwave time duration (MTD) and microwave time zero (MTZ) for LW/BCC, its macro and micro performance are analyzed. Finally, the Life cycle Assessment (LCA) method is used to evaluate the whole cycle of low-carbon LW/BCC from production to service. The results show that a reasonable microwave pre-curing system can effectively shorten the curing cycle during the preparation of LW/BCC. A 1-minute microwave pre-curing during the induction period can improve the compressive strength of the sample by about 150% and increase its long-term strength. Based on LCA results, it can be noticed that the newly proposed method could decrease the natural resources depletion, ecotoxicity, ozone depletion and carbon emissions of LW/BCC by 94.71%, 90.36%, 87.3% and 84.45%, respectively.

Attributional and consequential life cycle perspectives of second-generation polylactic acid: The benefits of integrating a recycling strategy

The climate crisis calls for a shift from petrochemicals to bio-based products to reduce environmental consequences. Polylactic acid (PLA) is one of the most widely used biopolymers, due to its mechanical properties and renewable origin, to produce bio-based compostable plastic for food packaging. The objective of this study is to determine the environmental feasibility of a second-generation PLA production based on wheat straw; and the role of a chemical recycling plant on the environmental performance of a bioproduct at an early design stage. A holistic assessment was performed through the Life Cycle Assessment (LCA) methodology considering both attributional and consequential perspectives, through a cradle-to-grave approach. The attributional LCA results show that lactic acid production was the main contributor due to the wheat straw pre-treatment and downstream separation and purification (DSP) processes. The integration of a recycling plant leads to a significant reduction of burdens, ranging from 1.38 to 0.44 kg CO2eq in the Global Warming category. Furthermore, consequential LCA results shows that the increased demand for substitute products for activities such as feeding, fertilisation and energy generation and the indirect emissions from land use change related to the conversion of land for the cultivation of raw materials are relevant factors in the environmental effects associated with the possible implementation of straw-based bioPLA production system.

Innovative Bioplasticizers from Residual Cynara cardunculus L. Biomass-Derived Levulinic Acid and Their Environmental Impact Assessment by LCA Methodology.

This work is focused on the application of Life Cycle Assessment (LCA) methodology for the quantification of the potential environmental impacts associated with the obtainment of levulinic acid from residual Cynara cardunculus L. biomass and its subsequent valorization in innovative bioplasticizers for tuning the properties as well as the processability of biopolymers. This potentially allows the production of fully biobased and biodegradable bioplastic formulations, thus addressing the issues related to the fossil origin and nonbiodegradability of conventional additives, such as phthalates. Steam explosion pretreatment was applied to the epigean residue of C. cardunculus L. followed by a microwave-assisted acid-catalyzed hydrolysis. After purification, the as-obtained levulinic acid was used to synthesize different ketal-diester derivatives through a three-step selective synthesis. The levulinic acid-base additives demonstrated remarkable plasticizing efficiency when added to biobased plastics. The LCA results were used in conjunction with those from the experimental activities to find the optimal compromise between environmental impacts and mechanical and thermal properties, induced by the bioadditives in poly(3-hydroxybutyrate), PHB biopolymer.

MarILCA characterization factors for microplastic impacts in life cycle assessment: Physical effects on biota from emissions to aquatic environments

Although plastics emissions pose hazards to ecosystem quality, life cycle assessment (LCA) methodologies do not yet include quantification of the potential impacts of plastic leakage. To address this gap in LCA, the MarILCA working group was founded. This work contributes to MarILCA's output by providing characterization factors for assessing the impacts of aquatic (marine and freshwater) microplastic emissions through the impact category of physical effects on biota and ultimately the ecosystem quality damage category. First, the existing exposure and effect factor (EEF) for micro- and nanoplastic emissions in aquatic compartments (Lavoie et al., 2021) is updated using additional toxicity data, delivering a generic EEF of 1067.5 PAF m3/kgin compartment. Second, fate factors (FFs) are developed for eleven different polymers (EPS, PS, PA/Nylon, PP, HDPE, LDPE, PET, PVC, PLA, PHA, TRWP), three shapes (sphere/microbead, cylinder/microfiber, microplastic film fragments) and five sizes (1, 10, 100, 1000, 5000 μm). To calculate the FFs, a detailed degradation model and a simplified sedimentation model are proposed. Polymer density and size play a major role in the fate, whereas the influence of the shape is less relevant. Ultimately, the EEF and FFs are combined to deliver midpoint and endpoint characterization factors (CFs). Uncertainty is calculated with Monte Carlo analysis. Default and archetype-based CFs are recommended to LCA practitioners in case the details of emission parameters are not fully known. CFs for 1 μm microplastic size are proposed as interim CFs for nanoplastic emissions. Finally, endpoint CFs are tested in case studies within the UNEP report “Supermarket food packaging and its alternatives: Recommendations from life cycle assessments”, assessing the relative magnitude of potential microplastic impacts compared to complete LCA results. The case studies confirm that the proposed methodology contributes to filling a gap in LCA and can assist environmental decision-making on single-use plastics and their alternatives.