Life Cycle Inventory Research Articles

Catchment-scale life cycle impacts of green infrastructures and sensitivity to runoff coefficient with stormwater modelling

Urban green infrastructure (GI) has been widely used in sponge city construction to manage hydrological processes. While studies on environmental benefits of GI from the perspective of whole life cycle assessment (LCA) have been reported in recent years, few have explored and compared the environmental performance of different GIs within a single catchment, which is directly linked to catchment-scale hydrological control. This study focuses on a Sponge City pilot project in Shenzhen, China, including three typical types of GI: permeable pavement, green roof, and sunken green space. By collecting hydrological data, land use, and life cycle inventory of GI and employing SWMM (Storm Water Management Model)-based stormwater modelling, we have revealed the environmental impacts at different stages of the life cycle of the GI scenario and three GIs through comparative and sensitivity analyses. Notably, we have disclosed, for the first time, the effect of the runoff coefficient in LCA. Our findings indicate that over the 30-year life cycle, the total environmental impact of the GI scenario is 24 % smaller than that of the hypothetical grey scenario. Permeable pavement exhibits the largest environmental impact per unit area, being 1.8 times and 7.6 times greater than that of the green roof and sunken green space, respectively. The operation stage of the three GIs significantly mitigates eutrophication and climate change. Furthermore, sensitivity analysis demonstrates that an increase in surface runoff undermines the environmental benefits of GIs. These results highlight the importance of embedding stormwater modelling into LCA, enabling catchment-scale integrated evaluation and equivalent assessment of different GIs within a single catchment whereby the influence of external factors such as climate change can be described, which aids in understanding the dynamic environmental performance of GIs. The proposed research framework and results are anticipated to provide valuable guidance for future GI construction and carbon-neutral policies.

Optimization of Car Use Time for Different Maintenance and Repair Scenarios Based on Life Cycle Assessment

New propulsion technologies and the development of electromobility increase the environmental efficiency of the transport sector. However, the current structure of car fleets with a large number of old cars with worse environmental parameters undermines the benefits of technological progress in the automotive industry. Older cars may require a more extensive service, involving a thorough overhaul, repair or even replacement of many parts. The result of using additional resources is a deterioration of environmental performance. This study considers various maintenance and repair scenarios and focuses on the use phase using the example of the popular Ford Focus passenger car model. The life cycle optimization model was used for environmental assessment, which determines the optimal duration of the car use phase, accounting for detailed service information and the type and environmental efficiency class of the different fuel versions. This model can be an effective tool for car fleet management and car replacement policy. Detailed life cycle inventories of 40 Ford Focus II diesel and petrol cars that represent all maintenance and repairs are the inputs to the life cycle optimization model. The inventory data were provided by the Ford Service Center in Szczecin (Poland), which regularly serviced the cars with a mileage of up to 200,000 km. Inventory at other stages of the cars’ life cycles was modeled using Ecoinvent data. The results show that by considering these vehicle servicing aspects on the basis of more detailed data, impact assessments are better represented compared to other studies. Depending on the replacement policy, the contribution of vehicle maintenance and repair can account for almost half of the cumulative life cycle burdens.

Environmental analysis of nylon 6,6 production from gamma-valerolactone derived from kenaf

Nylon, known for its outstanding physical properties, durability, and affordability, is in high demand across various industries. The majority of nylon is currently produced using petroleum-based raw materials, which causes negative environmental impacts such as greenhouse gas emission and fossil resource depletion. This has motivated research and development of eco-friendly production methods using biomass, we propose the environmental feasibility of kenaf-based nylon production strategy in the Republic of Korea. This study carries out a life cycle assessment (LCA) for analyzing the global warming potential (GWP) and fossil resource scarcity (FRS) of nylon 6,6 production from gamma-valerolactone (GVL) derived from kenaf. The life cycle inventory is analyzed based on the simulation data of the GVL-to-nylon 6,6 process and the two major environmental impacts are quantified when the biorefinery is operated at the Saemangeum agro-bio industrial cluster in Jeollabuk-do in Republic of Korea. The nylon 6,6 production in the Saemangeum can effectively reduce the GWP (61%) and FRS (67%) compared to the conventional nylon 6,6 production. Furthermore, if the GWP of the two materials used in the production of nylon 6,6 (HMDA, NaOH) can be reduced by 50%, the GWP per kilogram of nylon 6,6 produced will be reduced by 43% (1.91 kg CO2 eq.).

Life cycle assessment of sitka spruce forest products grown in Ireland

PurposeThe purpose of this study is to quantify the environmental impacts of Sitka spruce timber products harvested from the forestry sector in Ireland. This data is typically country-specific and is required to accurately quantify the environmental impacts associated with its production to better understand the impacts on the environment.MethodsA representative model utilising the ReCiPe midpoint approach is developed for the forest sector and the production of log products in Ireland from primary data collected from the national forestry agencies, boardmill and sawmills over a 12-month period, where the last two represent 100% and 67% of the national production volume, respectively. The model was analysed using Life Cycle Assessment (LCA) and the resulting environmental impacts of log production are presented for two different boundary conditions, namely ‘cradle-to-forest road’ and ‘cradle-to-factory gate’ which considers the transport of the logs for further processing.Results and discussionThe results are presented for the reference functional unit of 1 m3 of Sitka spruce log product but the results are also shown for 1 rotation of 1 ha of forest area, which allows comparisons with existing studies that utilise similar metrics such as a given area of forest. The results show that typically, clearfell operations are the most significant contributor to all impact categories. The contribution of the remaining operations in descending order of magnitude are thinning operations, forest road construction and maintenance, site preparation options, seedling production and finally forest maintenance operations. The extended model (‘cradle-to-factory gate’ model), which includes transport or delivery, has demonstrated a significant contribution due to transport alone where it was found to be responsible for, on average, 50% of each impact category presented (excluding land occupation) highlighting its significance.ConclusionsThe underlying Life Cycle Inventory (LCI) data, which quantifies the total outputs of emissions and substances to air, land and water, is presented. It can be seen that the contribution of different operations varies significantly dependent on the log type which provides important data which can be further incorporated into future studies for downstream products utilised in the construction industry.

Gas Induced Superheated Slurry: Industrial Applicability, Energy Savings and Sustainability in High Pressure Die Casting

Objective of the paper is to present the latest applications of GISS technology, a little more than six years since the launch in the die casting industry. Industrial applicability and robustness of the solution have been the main targets of GISSCO development which is focussed on providing a technology appliable to mass production with short lead time and cost effectiveness. Based on the concepts of viscosity control and feeding compensation the GISS technology can lead to reduction of production costs (energy, lubrication, waste disposal, die life extension) as well as increase of the casting quality. Life Cycle Inventory and Carbon Footprint calculation of a case study are presented.

Life Cycle Assessment of Composites Additive Manufacturing Using Recycled Materials

Additive manufacturing (AM) of composite materials is promising to create customizable products with enhanced properties, utilizing materials like carbon fibers (CFs). To increase their circularity, composite recycling has been proposed to re-introduce the recovered components in AM. A careful evaluation of recycling is necessary, considering the sustainability and functionality (i.e., mechanical properties) of the recovered components. Thus, Life Cycle Assessment (LCA) is applied to estimate the environmental impacts of AM via Fused Filament Fabrication (FFF), using virgin or recycled CFs via solvolysis at a laboratory scale. This study aims to provide a detailed Life Cycle Inventory (LCI) of FFF and evaluate the sustainability of using recycled CFs in AM. For both virgin CF manufacturing and CF recycling, electricity consumption was the main contributor to environmental impacts. CF recovery via solvolysis resulted in lower impacts across most impact categories compared to AM with virgin CFs. Different scenarios were examined to account for the mechanical properties of recycled CFs. AM with 75% recycled CFs, compared to 100% virgin CFs undergoing landfilling, resulted in over 22% reduction in climate change potential, even after a 50% loss of recycled CF functionality. Overall, this study offers insights into the LCI of FFF and shows that CF recycling from composites is worth pursuing.

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.

Parameterized Modeling of the Energy Demand of Machining Processes as a Basis for Reusable Life Cycle Inventory Datasets

Manufacturing processes have a significant contribution to energy consumption and related greenhouse gas (GHG) emissions in a product’s life cycle. Today, information on GHG emissions is increasingly demanded from companies in a life cycle perspective, based on the methodology of Life Cycle Assessment. Manufacturing companies supply producers of final products and are, therefore, requested to provide data on GHG of their manufacturing processes and resulting products. Obtaining such data for real-world manufacturing processes represents a huge effort. This challenge can be overcome with the use of a parameterized model, the Extended Energy Modeling Approach (EEMA), that has been developed for the machining process, which is a widespread industrial manufacturing process. The model calculates the total energy demand from power key values, which report the average power consumption of the constant and variable units of the machinery equipment, the consumer groups, as well as the different operating states of the equipment. Therefore, EEMA enables the reuse of a single measurement campaign for follow-up investigations of the specific machine tool, thereby significantly improving the efficiency of data acquisition for the calculation of the total energy demand and life-cycle-based GHG emissions. To use EEMA for the compilation of life cycle inventory datasets, methodological requirements were analyzed to derive a procedure for LCA-compliant datasets for machine tools. The key findings of applying the EEMA for the case study of a turning machine show that the constant consumer groups have a significant influence on the total energy demand. The share of the variable consumer groups in the total energy demand increases with increasing machine utilization but is always below 5%.

Regionalized life cycle inventory data collection and calculation for perennial forage production in Canada: methodological best practices and limitations

Abstract Purpose In Canada, 95–99% of produced forages are consumed domestically each year, mainly by beef cattle. Despite their importance, their contribution to the Canadian livestock industry and associated ecosystem services has not been investigated. This study developed a life cycle inventory (LCI) of perennial forage production in Canada averaged from 2009 to 2018. Methods LCI data were sourced or calculated from up-to-date, regionally resolved sources and models. Inputs to perennial forage production included the following: concrete, steel, and plastic usage; machinery fuel consumption; electricity, natural gas, and water use for irrigation; and synthetic and organic fertilizer, lime, and herbicide use. Assessed emissions included ammonia and nitrous oxide (N2O); carbon dioxide from energy use; herbicide, nitrate, and phosphate losses; and soil carbon accumulation. Results were expressed per metric tonne of harvested perennial forage dry matter at provincial and regional scales—Western Canada [British Columbia (BC), Alberta (AB), Saskatchewan (SK), Manitoba (MB)] and Eastern Canada [Ontario (ON), Québec (QC)]. Results and discussion Rates of inputs varied, with generally lower nutrient but higher herbicide application in West vs. East. Irrigation was highest in BC, followed by AB and SK; energy consumption was highest in BC and lowest in QC. Higher N2O losses and nutrient losses via leaching and runoff in the East were partially due to greater soil moisture. Although total harvested perennial forage area declined from 6.43 to 5.23 million hectares from 2009 to 2018, these lands continued to accumulate soil carbon. The time period used to calculate average yields affected LCI estimates, as prairie yields were lower 1994–2003/1999–2008 due to drought. Furthermore, soil carbon sequestration estimates were affected by the annual change coefficients employed, underscoring the need for careful interpretation of LCI outputs. Results were compared to other studies and highlighted the importance of the choice of data and methods in creating LCI, and the need for transparency. Conclusions This first national LCI of perennial forage production in Canada provides a baseline for LCI inputs and outputs associated with this sector, highlighting provincial and regional differences. Outputs can be used to conduct future life cycle assessments to assess the environmental impacts of forage production and generate recommendations to improve sustainability, and for education and marketing purposes. This study demonstrates methodological best practices for LCI data mining and calculations, within available data and model limitations, thereby identifying gaps and providing a roadmap for other countries or sectors to develop detailed forage LCI.

A Parametric BIM Framework to Conceptual Structural Design for Assessing the Embodied Environmental Impact

Decisions made in the early design stage have a significant effect on a building’s performance and environmental impact. In practice, a conceptual design is performed by an architect, while a structural engineer begins to work in later phases when the architectural concept has already evolved. However, the geometry and form of a building directly determine the type of structure and applicable materials; therefore, the conceptual design phase gives rise to examining alternative solutions. This paper presents a method for generating alternative structural solutions in the conceptual design phase and examining their embodied environmental impact by integrating parametric design and building information modeling (BIM). Rhinoceros and Grasshopper were used to develop the parametric script, which includes the generation of geometrical variations, the automatic definition of initial cross sections for the load-bearing elements based on in-built structural design approximations, the datasets for embodied environmental impact of the used building materials, the generation of life cycle inventory (LCI), the automatic calculation of life cycle assessment (LCA) results based on the geometry, and the conversion of the parametric model into building information model. The method was demonstrated using a case study of 48 different alternative solutions for an unheated warehouse made of steel frames. Based on the results, the areas with the greatest energy impact were identified. The case study analysis also illustrated that the applied cross section may have a significant effect on the impact categories. The results draw attention to the complexity of LCA calculations even in the case of a simple structure containing a limited number of variables, where parametric design can serve as an effective tool for a comprehensive environmental impact assessment.

Circular Bioeconomy Practices in the Greek Pig Sector: The Environmental Performance of Bakery Meal as Pig Feed Ingredient

Food systems and, to an extent, the pig sector are major contributors of greenhouse gas (GHG) emissions globally. At the same time, significant amounts of waste are produced from the food sector. The aim of this study is to examine the implementation of circular bio-economy practices in the Greek pig sector to improve its environmental performance. More specifically, in collaboration with a pig farm in Northern Greece and a waste management company, the collection and processing of bakery by-products was organized to produce bakery meal (BM) to integrate it in the diets of fattening and growing pigs. Using Life Cycle Assessment (LCA) methodology, the environmental performance of 20% BM inclusion in pig diets was examined in comparison with the conventional feedstock. BM experimentally replaced corn, wheat, barley, and soya bean from conventional feedstock. The Life Cycle Inventory (LCI) was based on the yearly average values of feed and energy consumption to produce 1 kg of living weight of pig on the pig farm. Life Cycle Impact Assessment (LCIA) was conducted with SimaPro v3.5, using Recipe Midpoint Hierarchical v1.6. The LCIA calculations exhibited that BM inclusion in pig diets can lead to significant land occupation decrease, approximately 30%, which is mostly related to reduced wheat and soya beans. The reduction of cultivated croplands also led to reduced fertilizer and pesticide application, which improved marine eutrophication and freshwater ecotoxicity impact by 20% while it significantly reduced risks of human carcinogenic toxicity by 25%. Moreover, the Greek pig sector exhibited a 5% capacity for overall improvement of its environmental performance, which relies on minimizing logistics when the pig farm conducted collection and processing of by-products. A basic assumption of this study is the assessment of bakery by-product quantities in the wider region of the pig farm. The availability of by-products, based on the reported experience, was limited, and the reliability of the supply was frequently disrupted. As such, the supply chain model of the central hub for the collection and processing of bakery by-products is proposed as more efficient for regulating logistic challenges and availability.

Life cycle inventory of Miscanthus production on a commercial farm in the US.

There has been considerable interest in use of Miscanthus (Miscanthus x giganteus) as a feedstock for bioenergy production due to its potential to reduce greenhouse gas emissions associated with cellulosic feedstock production and more recently for alternative uses as a biomass crop. To date, data on Miscanthus production in the US has been based on small scale research plots due to the lack of commercial scale production fields. Research plot yields are often much higher than commercial fields for a variety of reasons including reduced spatial variability and location on better quality farmland. The objectives of this study were to quantify the inputs for production of Miscanthus at the commercial farm scale, evaluating methods to characterize fuel use for establishment and management of Miscanthus production and using satellite data to characterize spatial yield variation of production fields. We logged energy use on agricultural machinery from Miscanthus production planted on more than 1000 ha of land and modeled N2O emissions and changes in soil carbon using DayCent. Although fuel use was higher for land preparation in fields with perennial vegetation, fuel to harvest Miscanthus dominated greenhouse gas (GHG) emissions (>90%) from agriculture machinery for crop management. The N2O emissions and changes in soil carbon were the largest source and sink of GHG emissions associated with Miscanthus production, respectively. Although ~ 50% of the established lands had Miscanthus yields < 5 Mg/ha, yields needed to be > 5 Mg/ha for ΔSOC to be positive. Given the large impact of yield on ΔSOC, net GHG for Miscanthus production with yields of 5 to 25 Mg/ha ranged ~130 to -260 kg CO2e/Mg biomass. Use of both energy use for Miscanthus harvest and satellite imagery were good methods to characterize spatial variability of commercial production fields. This demonstrates the potential to use this within field yield data to better understand factors driving subfield yield variability and use of satellite data to quantify early yield predictions.

Environmental life cycle assessment of recombinant growth factor production for cultivated meat applications

Growth factors are critical components of current serum-supplemented and serum-free media formulations for cultivated meat production. However, growth factors have been excluded, estimated using proxies, or modeled using proprietary data in existing environmental assessments of cultivated meat products. Cell culture media has been identified as a hotspot in such studies, therefore it is important to accurately quantify the environmental impacts of growth factor supplementation. To address this gap, this study applied life cycle assessment (LCA) methodology to comparatively assess the environmental impacts of recombinant growth factor production for cultivated meat applications. Life cycle inventories were developed for four recombinant growth factors (IGF-1, FGF, TGF-β, and PDGF) produced using a novel bench-scale process. The functional unit was selected as 1 mg of produced growth factor. The results indicate that recombinant growth factors can have significant environmental impacts within cultivated meat systems, despite being used in very small quantities. For example, the global warming potential of production of 1 mg of IGF-1, FGF, TGF-β, and PDGF was estimated to be 0.1, 0.04, 0.2 and 0.2 kg CO2 eq, respectively. Future research should explore the sustainability of producing food-grade growth factors at scale to meet the needs of the expanding cultivated meat industry or identifying alternatives to growth factors that have lower impacts on the environment.

Trade-offs between accuracy and efficiency in BIM-LCA integration

PurposeIn the last decades, various building information modeling–life cycle assessment (BIM-LCA) integration approaches have been developed to assess the environmental impact of the built asset. However, there is a lack of consensus on the optimal BIM-LCA integration approach that provides the most accurate and efficient assessment outcomes. To compare and determine their accuracy and efficiency, this study aimed to investigate four typical BIM-LCA integration solutions, namely, conventional, parametric modeling, plug-in and industry foundation classes (IFC)-based integration.Design/methodology/approachThe four integration approaches were developed and applied using the same building project. A quantitative technique for evaluating the accuracy and efficiency of BIM-LCA integration solutions was used. Four indicators for assessing the performance of BIM-LCA integration were (1) validity of LCA results, (2) accuracy of bill-of-quantity (BOQ) extraction, (3) time for developing life cycle inventories (i.e. developing time) and (4) time for calculating LCA results (i.e. calculation time).FindingsThe results show that the plug-in-based approach outperforms others in developing and calculation time, while the conventional one could derive the most accuracy in BOQ extraction and result validity. The parametric modeling approach outperforms the IFC-based method regarding BOQ extraction, developing time and calculation time. Despite this, the IFC-based approach produces LCA outcomes with approximately 1% error, proving its validity.Originality/valueThis paper forms one of the first studies that employ a quantitative and objective method to determine the performance of four typical BIM-LCA integration solutions and reveal the trade-offs between the accuracy and efficiency of the integration approaches. The findings provide practical references for LCA practitioners to select appropriate BIM-LCA integration approaches for evaluating the environmental impact of the built asset during the design phase.

Environmental impact of wall multilayer coating systems containing aerogel-based fibre-enhanced thermal renders

This research evaluates the environmental impacts of aerogel-based fibre-enhanced thermal insulating renders and the respective multi-layered coating system to apply on buildings' envelopes, contributing to their energy efficiency. The environmental analysis was performed using a Life Cycle Assessment (LCA) methodology with a cradle to gate approach, including the Life Cycle Inventory (LCI) of the protective coating system while evaluating the Abiotic Depletion Potential from fossil fuels (ADP-ff) and the Global Warming Potential (GWP). A sensitivity analysis of the silica aerogel aggregate contribution to the overall environmental impacts was also carried out, and a study of the impact that the introduction of natural and synthetic fibres had on the thermal render’ formulation. The results showed that the most critical environmental contribution is related to the raw materials incorporated in the thermal render representing more than 90% of the total environmental impact when a cradle to gate analysis is made. It was also verified that even a small powder substitution by natural and synthetic fibres (0.10–0.50% of the total powder volume) could have significant impacts on the environmental performance of the aerogel-based thermal render. This research also showed that these thermal renders, although at a developing stage, show a promising application potential from the environmental point of view and that further optimisation steps can lead to even lower impacts.

An integration of machine learning models and life cycle assessment for lignocellulosic bioethanol platforms

The availability and accuracy of data play a critical role in the development of Life Cycle Assessment (LCA) models, as they directly impact the effectiveness and reliability of the model. Machine learning (ML) approach has the potential to improve the data quality, leading to enhanced performance of LCA models. In this study, ML algorithms (random forest, extreme gradient boosting, and artificial neural network) were applied to predict the ethanol yield and NaOH consumption, which were key life cycle inventories for lignocellulosic bioethanol process. The prediction models exhibited a decent level of accuracy for ethanol yield (accuracy ∼ 0.85) and NaOH consumption (accuracy > 0.8). In addition, ML algorithms (genetic algorithms, particle swarm optimization, and simulate annealing) were applied to identify optimal feedstock characteristics and conditions for maximum ethanol yield. The optimization models showed an 18% improvement compared to the highest yield from the dataset (0.41 g/g). The ML models (prediction and optimization algorithms) were further integrated with the LCA model (GREET1) to enhance the ethanol yield and to reduce greenhouse gas (GHG) emission for target feedstocks. This resulted in a 6% and 19% improvement in ethanol yield and an approximately 8% and 14% reduction of GHG emissions for grass and corn stover, respectively. This study demonstrates the feasibility of utilizing ML to predict LCA metrics for the development of LCA models and to optimize the process parameters to minimize environmental impact.

Life cycle assessment of an integrated xylitol biorefinery with value-added co-products

PurposeThis manuscript comprises a detailed life cycle assessment of an integrated xylitol biorefinery with value-added co-products. The biorefinery utilizes wheat straw as lignocellulosic feedstock and employs bio-based processes to produce xylitol as the main product and succinic acid as a co-product. The biorefinery was conceptually designed in an optimization-based framework and assessed through a techno-economic analysis published in the authors’ prior publications.MethodsThe goal is to determine the environmental impacts of the xylitol biorefinery and to compare the effects of bio-based production in the biorefinery to the current chemical production processes of xylitol. The scope is set as cradle-to-gate to allow a direct comparison of the chemical processes. The presented life cycle assessment was performed according to the standardized ISO procedure.ResultsThe reference unit is related to the feedstock as multiple products are produced, and an economic allocation is chosen. The life cycle inventory is based on secondary data from process simulations stemming from earlier published work. The impact assessment is performed with the ReCiPe 2016 Midpoint H V1.05 method and the IMPACT2002 + method since the available data of the life cycle assessment for the chemical processes was obtained with the latter. The characterization of the impacts shows high impacts for the terrestrial, marine, and human carcinogenic toxicity impact categories and a comparatively low impact on global warming.ConclusionsThe results are interpreted and assessed with an additional sensitivity analysis. Furthermore, the results are compared with the two chemical production processes. The comparison shows lower impacts of the xylitol biorefinery compared to the standard chemical production process but slightly higher impacts compared to the proprietary production process of DuPont, which employs a high level of process integration. These results are further discussed and contextualized.

Decarbonizing the lime-based construction materials industry: A practical guide for cradle-to-gate life-cycle inventory

This paper presents an integral parametrized framework to calculate the life-cycle inventory (LCI) in lime-based construction materials manufacturing, utilized for implementing decarbonization strategies in the LCI. The calcination operation is identified as the main source of CO2 emissions, with 0.79 tCO2/t CaO being inevitable (65 % of total emissions). Kiln fuel combustion contributes up to 35 % to emissions. Decarbonization strategies are ranked as: carbon capture, carbon direct avoidance, and circular economy. Parallel Flow Regenerative Kilns result in 40 % lower energy consumption compared to Long Rotary Kilns. Substituting lignite with natural gas can reduce emissions by up to 17 %. Direct CO2 separation from calcite decomposition, coupled with thermal energy recovery, can capture 65 % of the CO2 emitted, reducing kiln energy consumption by 15 % and CO2 emissions from fuel combustion by 13 %. The high purity of captured CO2 offers potential for future use as a valuable by-product. Supplementary raw materials in lime-based binder production have limited effects on CO2 emissions due to unavoidable emissions from calcite decomposition. The proposed process-oriented parametric methodology empowers Life Cycle Assessment practitioners, reducing reliance on generic databases for rigorous and transparent inventory calculations.

Data management in life cycle assessment: a case study of wastewater treatment.

To assess the environmental impact of wastewater treatment, life cycle assessment (LCA) is a frequently applied instrument. However, these studies often require large amounts of data. The complexity and heterogeneity of these data result in the need for a systematic data management approach. Especially the generation of the life cycle inventory (LCI) holds the potential to be facilitated by automation. A case study in the wastewater sector was used to demonstrate the implementation of data management. A database structure was developed to store the raw data of the wastewater plants (WWTPs) and make it accessible through code. The code interacted with the database, implemented calculations, and automatically created the inventory based on the processed data. The database provides a consistent structure for the raw data and can also be used for backup purposes. Because it is machine-readable it can be accessed through the code that enables the automated generation of the LCI. As a proof of concept, a sequence of the code is provided with a user interface and can be tested online. We found that for most use cases, basic programming tools were sufficient for systematic data management, and, therefore, the approach is considered accessible for LCA practitioners.

Pyrometallurgical recycling of different lithium-ion battery cell systems: Economic and technical analysis

The global trend towards electromobility raises questions about the treatment of lithium-ion batteries from battery-electric vehicles at the end-of-life stage. The paper examines two pyrometallurgical recycling routes (a direct and a multi-step process) for different lithium-ion battery cell compositions (NMC333/C, NMC811/C, LFP/C, NMCLMO/C) from a techno-economic perspective. Based on lifecycle inventories per recycling process and battery type, the profitability of these two recycling processes is investigated by conducting a total cost of ownership analysis for typified pyrometallurgical recycling plants on a pre-industrial scale. The results reveal that the cell chemistry will have a major impact on the profitability of recycling. In particular, it appears to be difficult to operate recycling profitably under current conditions for low-cobalt and low-nickel battery types. A sensitivity analysis shows different levers and their respective limitations for increasing the process profitability of recycling different lithium-ion battery cell systems.