Life Cycle Assessment Framework Research Articles

Assessing Environmental Impact: Organosolv Extraction of Cellulose Pulp from Wood Waste

In the upcoming years, the paper industry is expected rely on containerboard for packaging, with approximately 80% of it being made from recycled fibers by 2020. Creating a new supply chain for fibers could help mitigate possible shortages. In this context, wood waste emerges as a valuable resource with the potential to serve as a plentiful and cost-effective reservoir for generating new materials, as cellulose fibers. This study presents an assessment of the environmental impact associated with the organosolv extraction of cellulose pulp from wood waste based on a previous in lab study conducted by the authors. The increasing demand for sustainable materials has prompted exploration into alternative methods for cellulose pulp production, with a focus on minimizing environmental footprint. Organosolv extraction, a promising technique, involves the use of organic solvents and acid catalysts to break down lignocellulosic biomass, resulting in high-quality cellulose pulp production. To evaluate the environmental implications of this process, a comprehensive life cycle assessment (LCA) approach was adopted. The LCA framework considers all stages of the organosolv extraction process, from wood waste collection to cellulose pulp manufacture, using a gate-to-gate approach. The functional unit for assessment is set as one ton of cellulose pulp. The dataset utilized for the LCA comprises primary data obtained from laboratory experiments, complemented by secondary data sourced from literature and the Ecoinvent life cycle inventory database. Furthermore, sensitivity analysis was conducted to assess the influence of key parameters on the environmental performance of the organosolv extraction process, with a focus on variations in energy consumption to identify potential areas for optimization and improvement. In summary, this study emphasizes the environmental aspects of utilizing organosolv extraction for cellulose pulp production from wood waste. Further research is warranted to explore energy consumption during the organosolv process for obtaining more precise data and optimizing the process. This could be achieved through pilot-scale experiments or utilizing process simulation software.

Life Cycle Assessment Framework for Diagnostic Imaging

The increasing focus on environmental sustainability is becoming essential in the diagnostic imaging sector, which is accredited for about 10% of the healthcare industry’s carbon footprint. A multitude of research initiatives investigated the environmental impacts of diagnostic imaging, encompassing factors like electricity consumption, carbon emissions, and waste generation from these procedures. Life Cycle Assessment (LCA) stands as a prominent method for structural assessment of environmental impacts, offering a detailed framework for examining the environmental consequences of specific processes. The aim of this study includes analyzing existing LCA approaches in literature to identify their limitations and to suggest an elaborate framework for LCA application in diagnostic imaging.Out of 17 original articles on environmental sustainability in radiology published since 2014, but only a part, 29.4% (5/17), described an LCA approach. The different characteristics of these studies provide valuable insights, enabling the proposal of a more comprehensive LCA research methodology.The reviewed articles did not present a uniform research outcome. According to the GreenHouse Gas (GHG) Protocol Corporate Standard, the optimal outcome for assessing environmental impact is the calculation of greenhouse gas emissions. For a thorough methodological approach in LCA, it is essential to cover all direct and indirect emissions associated with diagnostic imaging. All studies (100%, 5/5) considered the electricity consumption of imaging equipment. Usage of consumables was included in 80% (4/5) of the studies. Only 40% (2/5) of articles considered auxiliary equipment like computers and contrast-medium injectors, as well as heating, ventilation and air conditioning (HVAC) systems. Factors like equipment manufacture, staff travel, and waste generation, though crucial to overall greenhouse gas emissions, were each covered in only 20% (1/5) of the studies. The articles also varied in their LCA versions, with two employing the detailed Cradle-to-Grave approach, while others used partial Cradle-to-Gate and Input-Output LCA methods.The insights from this analysis could lead to a valuable framework for a new LCA methodological approach in diagnostic imaging. This novel approach is designed to overcome the limitations observed in existing research, offering a more comprehensive analysis. By enhancing the LCA framework, it will be possible identify the phases in diagnostic imaging that have the most substantial environmental impact, allowing for the development of more targeted strategies to reduce GHG emissions associated with diagnostic procedures.

A Systematic Review of Social Sustainability Indicators for Water Use along the Agricultural Value Chain

The concept of sustainable water use serves as an indicator of environmental, economic, and social pressure on freshwater resources globally; however, the social element of sustainability is not well researched within water-consumption studies. The objective of this paper is to consider the current state of the literature on social sustainability indicators for water use in agriculture, as well as to describe the social (people) element of sustainability and establish water use as an element of society. By combining viewpoints, systematic literature reviews address research topics with a strength that no single work can have. From 314 papers published between 2013 and 2023, 42 papers were eligible for the review. This work employed a mixed-methods approach that included a systematic review following the (PRISMA) framework, scientific mapping through VOSviewer software (version 1.6.19), thematic reviews, and a review of the grey literature retrieved from artificial intelligence and deep learning technologies. The findings indicate that social sustainability indicators are based on environmental indicators. There are no set standards for what to consider as a social indicator of water use or for how these indictors can be measured. Life-cycle assessment and water-footprint assessment frameworks have shown progress with indicators that capture the social value of water such as productivity-reducing externalities, equity, and jobs per cubic metre of water.

Life Cycle Assessment of Pervious Pavements: Integrative Review and Novel Ideas of Analysis

Life Cycle Assessment (LCA) and Life Cycle Cost Assessment (LCCA) are essential tools for environmental and economic assessment and decision-making in an evolving world with continuous climate change. In the same conditions, one of the most used and assessed solutions for facing climate change is using pervious pavements, with many papers proving its benefits. However, the literature has shown a need for more research on the LCA methodological aspects in the context of new green infrastructure. This research aims to review pervious pavements, LCA and LCCA combined, while discussing possible differences in boundaries, functional units, and other parameters. Thus, a string search was performed, leading to 89 documents. The main results indicate LCA is usually scope-bounded in the field of pervious pavements, with different benefits and characteristics, such as traffic impact, urban heat island effects, and carbonation. As for LCCA, private and public cost differentiation provide a scope definition and monetisation difficulties. In conclusion, both tools offer promising applications in pervious pavements. As a significant deliverable and recommendation of this paper, both LCA and LCCA theoretical frameworks were provided based on the benefits and specific characteristics included in the literature. These frameworks introduce novel ideas and perspectives, inviting further exploration and discussion.

Some modeling challenges in dynamic life cycle assessment

Life cycle assessment (LCA) has been a mainstream tool to evaluate the environmental impacts of products, services, and systems. Current LCAs inherently rely on the static basis and commonly fail to include temporal considerations. To better assist in the decision-making for sustainable development, dynamic LCA has been initiated to answer more complex and interdisciplinary questions. As in its initial phase, dynamic LCA faces many modeling challenges that at the same time are meaningful research opportunities. In modeling dynamic LCA, there are several key aspects that need more attention for contribution and close collaboration across the first three phases of the LCA framework.

A Theoretical Framework to Promote LCA in the Construction Industry of Saudi Arabia

The building and construction sector in the Kingdom of Saudi Arabia (KSA), experiencing rapid growth, is in the early stages of embracing sustainability measures. In the years ahead, the booming building sector in business-as-usual scenarios may pose serious energy and environmental challenges for the Kingdom. This situation will require the Saudi building sector to adopt robust sustainability measures. Embedding life cycle assessment (LCA) as a standard practice can be a useful strategy for improving the energy and environmental footprint of buildings. This paper proposes a theoretical framework within which to promote LCA in the Saudi Arabian construction industry. This framework comprises three pillars: policy, social, and technical. The framework covers the role of the Saudi building sector’s stakeholders such as policy makers, building industry professionals, representatives of relevant governmental bodies, and academics. Adaptation of this LCA framework can help substantially improve the energy and environmental performance of buildings. The proposed LCA framework is aligned with the international as well as the Saudi government’s drive for sustainability in the building sector.

Sustainable utilization of incineration bottom ash in pavement construction: Environmental impacts and life cycle assessment

The global drive towards sustainable development has prompted a notable shift in civil engineering practices towards utilizing secondary materials, such as incineration bottom ash (IBA). The literature review underscores the relevance of waste incineration and the crucial need for effective IBA management strategies. Existing studies, however, reveal a dearth of studies within the life cycle assessment (LCA) framework focusing on understanding IBA characteristics and field conditions. The study addresses this gap by proposing an LCA to assess the environmental implications of substituting natural aggregates with IBA in pavement layers. A comparative LCA was carried out, where different scenarios of reuse of IBA (as produced, treated, or with restrictions) were assessed against a baseline scenario that represents the conventional use of aggregates in roads and landfilling of IBA. The ReCiPe technique, incorporating a hierarchist perspective, was employed to assess impacts across different problem-oriented categories. Additionally, this study also explores the impact of data variability on LCA outcomes, considering changes in landfill height, pavement infiltration rate, time duration, and IBA transportation distance. The analysis indicates that incorporating IBA in road layers can significantly reduce impacts on non-toxic categories like global warming by over 35 %. However, the leaching properties of untreated IBA contribute to a more than 28 % increase in human carcinogenic toxicity, rendering it environmentally unsuitable for road layer reuse. The comparative study illustrated that reusing treated IBA is the most sustainable approach, remaining effective up to a distance of d + 15 km. In cases where treatment is not feasible, utilizing IBA with restrictions is recommended up to a distance of d + 5 km (d represents the transportation distance for natural materials). This research fills a critical gap in the literature by providing a framework to assess IBA reuse in road construction, thereby advancing the discourse on sustainable materials management in the construction industry.

Life cycle assessment of methods for recycling retired ternary lithium batteries

Electric car sales in China are soaring. However, the battery life service is generally short, leaving room for dramatic waste related to different types of ternary lithium batteries. Since batteries contain substantial amounts of toxic substances, wrong recycling methods may significantly rise environmental pollution. Currently, China's Li-ion batteries recycling technologies are poor and research dealing with the environmental impact of recycling waste ternary lithium batteries by traditional hydrometallurgical technologies in China is not sufficient. In this paper, a life cycle assessment framework was carried out to analyze the environmental impacts of recycling LiNixCoyAl1-x-yO2 (NCA) and LiNixMnyCo1-x-yO2 (NMC) batteries using conventional hydrometallurgical techniques implemented in traditional Chinese plants. The freshwater ecotoxicity, human carcinogenicity and marine ecotoxicity of NCA batteries were higher than those of NMC batteries when the batteries were recovered by the traditional hydrometallurgical recovery method. The traditional recycling method would bring more toxicity to the environment and the traditional hydrometallurgical route is not suitable for recycling NCA-type ternary lithium batteries. Moreover, the recycling process of all three types of batteries displayed an impact on the environment with negative growth and the highest impact on the environment during the initial stage of recycling. Overall, new directions and technical updates for China's power battery recycling enterprises were provided, which can be useful for future planning.

An integrated life cycle assessment and energy simulation framework for residential building walling systems

Designing building wall systems is a multi-criteria problem characterised by a complex interplay of variables that drive long-term energy and environmental performance. Achieving holistic sustainability outcomes will require the application of life cycle thinking to the design and evaluation of building walling systems. However, the aspiration for minimising operational and embodied energy and mitigating the environmental impacts requires conflicting strategies. Therefore, this study proposes a comprehensive, integrated life cycle and energy simulation (ILES) methodology for analysing different walling systems of residential buildings in India and Australia. This method involves performing a process-based life cycle assessment to compute the environmental impacts of various walling materials, followed by energy modelling to evaluate the performance of these materials in the operational phase of buildings in combination with embodied energy analysis, which accounts for energy consumption during the material manufacturing phases. The results reveal that insulated cavity-clay masonry or concrete walls with extruded polystyrene are favourable Australian walling options, while metal cladding-based walling systems have significant environmental and energy burdens. For India, autoclave aerated block, fly ash bricks, and concrete block-based walling systems are recommended, while reinforced concrete and clay brick walls exhibit significant environmental and energy burdens. This study also advocates the consideration of supply chains in mitigating Scope 3 emissions from building walling systems in residential buildings.

Light-duty passenger vehicle electrification in China from 2021 to 2050 and associated greenhouse gas emissions: A dynamic fleet perspective

The electric vehicle is seen as a promising technology to decarbonize road transportation. However, the long-term and fleet-scale impacts of the electric vehicle promotion in China are still underexplored. To investigate the mitigation potential of light-duty passenger vehicles electrification, a dynamic fleet-based life cycle assessment framework is constructed to calculate the annual greenhouse gas (GHG) emissions in China from 2021 to 2050. It is estimated that the annual fleet GHG emissions will peak at 1.10 ∼ 1.18 Gt between 2028 and 2031, and gradually decrease to 0.53 ∼ 1.04 Gt CO2 eq in 2050. Under the most sustainable pathway (SSP1), the aggressive electrification scenario (SSP1-EV2040) is projected to reduce accumulative life cycle GHG emissions by 5.4Gt CO2 eq (17 % of the accumulative emissions in SSP2-BAU). The regional distribution of GHG emissions and electricity use shows a downward trend from east to west, revealing the necessity of China’s regional-specified strategy..

Climate change substitution factors for Canadian forest-based products and bioenergy

Evaluating the climate change mitigation potential of the forest sector requires a holistic approach based on forest carbon (C) sequestration, C storage in harvested wood products (HWP) and substitution on markets. High uncertainty is associated with substitution factors, that express avoided fossil greenhouse gas (GHG) emissions from the use of forest-based products in replacement of GHG-intensive materials and fossil fuels. Few studies have focused on the development of substitution factors in Canada, resulting in the use of unrepresentative generic data. Here, we provide a framework to reduce uncertainties related to substitution factors for primary wood products in a Canadian context. A life cycle assessment framework is used to quantify fossil GHG emissions for a baseline and a wood-intensive scenario. For solid product substitution, we focused on the construction sector and analyzed a range of innovative wood buildings with steel and reinforced concrete as alternative materials. We found non-weighted averages of 0.80 tC/tC for sawnwood and 0.81 tC/tC for panels. For energy substitution, we analyzed cases with different specifications on biomass product, facility type and alternative fossil fuel source in non-residential heat production and biofuel transportation sectors. We found a non-weighted average of 0.80 tC/tC for non-residential heat production and 0.51 tC/tC for biofuel transportation, that can be interpreted as 0.91 tC/tC for heavy fuel oil, 0.69 tC/tC for light fuel oil and 0.68 tC/tC for natural gas substitution. These results provide a benchmark for substitution factors in Canada, to help guide forest management strategies for climate change mitigation.

Critical impacts of energy targeting on the sustainability of advanced biobutanol separation

Biobutanol stands out as an advanced renewable biofuel, yet its production through fermentation yields a low butanol concentration, necessitating expensive and energy-intensive separation methods, particularly by distillation. Alternative approaches, including adsorptive separation, have emerged, with the 2-column zeolite-based process showing promise. This study employed Aspen Plus for simulating adsorptive separation, utilized Pinch technology for heat integration, and analyzed various alternatives using the life cycle assessment (LCA) approach. Compared to the base case, which relied on our previously acquired experimental data and further purification through atmospheric distillation, the adoption of indirect heating/cooling adsorption reduced heating energy demand by 59.5%. Additionally, cooling energy usage was increased notably by 68.9%, and chilling prerequisites were eliminated. The implementation of Pinch technology further reduced heating and cooling energy requirements by approximately 36%. Multi-pressure distillation was also explored, revealing its potential to reduce heating energy consumption by 46.6%, accompanied by a modest 6.2% increase in cooling energy demand. A gate-to-gate LCA framework was used to evaluate the environmental impacts. The results showed that the combination of indirect heating/cooling adsorption, multi-pressure distillation, and energy-efficient practices resulted in over a 98% reduction in damages related to human health, ecosystem well-being, and resource depletion compared to the base case. Prioritization of key performance indicators revealed that human health had the most significant influence, with prominent midpoint effects attributed to human toxicity and global warming. This study underscores the pivotal role of energy targeting in curtailing energy consumption and enhancing the sustainability of adsorptive biobutanol separation.

Climate impacts of digital use supply chains

Information and communications technology (ICT) has become an indispensable part of our lives. Prior research on climate impact of ICT devices and services mostly makes use of life cycle assessment and energy modeling frameworks focused on embodied greenhouse gas (GHG) emissions. Because these perspectives emphasize the GHGs emissions associated with the construction and distribution of digital devices along production supply chains, not much is known about the GHGs emissions monitored or facilitated by digital device use. In this study, we propose the concept of digital use supply chains (DUSCs) as an orthogonal dimension of digital devices’ life cycle. DUSC refers to the production activities and resource consumption recorded by digital devices. We propose a framework to conceptualize and quantify digital behavior-related GHGs emissions through use of the Screenomics paradigm, where users’ digital screen data are unobtrusively collected moment-by-moment. Through Screenomics’ granular recording of users’ digital behavior, we evaluate behavior-based GHGs emissions traced by the digital devices. DUSC connects individual’s digital behaviors to their global climate change impact, contributing to a more nuanced and complete evaluation of the climate impacts of the digital economy. Our single-case study indicates the estimated scale of the GHGs emissions linked to a user’s one-day digital activities could be three orders of magnitude (1000 times) higher than the emissions associated with the device life cycle alone. DUSC could enable climate change mitigation at a meaningful, actionable level through personalized educational or behavior change programs, and also facilitate novel data-driven feedback loops that may provide digital device users with insights into their personal climate impacts. Recognition and future study of DUSC could accelerate the quantification and standardization of a ‘carbon handprint’ of digital devices and create positive climate impacts from digital products and services.

Advancing environmental assessment of the circular economy: Challenges and opportunities

The lifecycle assessment (LCA) framework is widely applied to comprehensively evaluate and improve the environmental performance of a circular economy (CE). The advances and application of LCA has been primarily restricted to evaluate the environmental performance of the CE at a micro-level, wherein the CE is implemented for a single product system.However, the CE can be operationalized at two broader levels: the meso–level (for eco-industrial parks) and the macro-level (for a city, state, or nation). Six methodological challenges emerge when applying LCA to a meso‑ or macro-level CE and remain unaddressed in the existing literature. This includes: selecting a relevant system boundary and functional unit, addressing data paucity and uncertainty, accounting for stakeholder behavior, assessing the trade-offs from renewable energy (RE) use, accounting for manufacturing and technology evolution, and quantifying displacement and rebound. This article proposes potential solutions and research priorities to address the above challenges.

Sustainability assessment of biofuel and value-added product from organic fraction of municipal solid waste

The current study aims to examine the techno-economic and environmental assessment of biorefinery development within a circular bioeconomy context by using an organic fraction of municipal solid waste (OFMSW) by extraction of lipids, carbohydrates, and proteins with 98, 51 and 62 % by mass of conversion efficiency and yield recovery, and value-added fractions production as well. Fatty acid methyl ester (biodiesel) and glycerol (biofuel) were produced by applying transesterification process, and the remaining biomass was converted into biocrude oil by thermal liquefication. The biorefinery using 613 kg of OFMSW produced biodiesel, glycerol, and bioethanol with 126 litter, 14.3 kg, and 172 litter respectively, as well as value-added fractions, such as biocrude oil with 78 kg. The environmental impact was assessed using the life cycle assessment (LCA) framework, ReCiPe2016 Mid-point (H) approach, through 18 different environmental categories. The key findings elucidate that Terrestrial ecotoxicity, Climate change, Fossil depletion and Human toxicity were the main impact categories which are potentially contributed 9.81E+02 kg 1,4-DB eq., 1.43E+03 kg CO2 eq., 2.04E+02 kg oil eq., and 8.08E+01 kg 1,4-DB eq. The normalization (person per equivalent) analysis revealed that only categories of resource reduction (fossil and metal depletion) are the key contributors to environmental degradation. The biorefinery system's total revenue was estimated at USD 6.817,509 million annually. The calculated revenue was USD 0.026 million daily in a shift of 8 h. The Net present worth (NPW) was calculated at USD 499.97 million by assuming a discount factor of 10 % and inflation rate of 5 % for 15 years. The project is considered feasible by demonstrating 7.15 payback year. This research showcased the efficient portrayal of the biorefinery system and succinctly conveyed the significant circular bioeconomy for a greener future. Thus, it could be helpful to the stakeholder's context towards techno-economic and environmental evaluation.

Dynamic Life Cycle Assessment Framework of Cold Food Storage Facilities

The imperative of responding to anthropogenic climate change that is driving energy infrastructure managers to implement resilience enhancing policies such as hourly scale dynamic pricing concurrently drives energy intensive industries to monitor energy usage at higher fidelity. This study proposes a Dynamic Life Cycle Assessment (DLCA) framework specifically tailored for cold food storage facilities which provide essential thermodynamic resilience to the human food web and consumes a large share of the web's energy footprint. Different from the conventional LCA, which delivers a snapshot of the environmental impacts and cost statically, DLCA can accommodate temporal variations in operating conditions and energy usage. It interacts with real-time monitoring data and fluctuating energy rates to provide a more accurate and time-sensitive environment impact and cost evaluation. Key parameters from real-time sensors and reference databases are summarized to lay the foundation for DLCA of cold food storage, like operating power and hours, shipment arrival time, and transportation fuel economy. Its feasibility and reliability are validated by scenarios that simulate different operating conditions, like shift change to utilize off-peak rate and change of packaging materials. The proposed framework allows facility operators and policymakers to pinpoint bottlenecks and seize opportunities for environmental impact and cost reduction.

Techno-enviro-economic analysis of second-generation bioethanol at plant-scale by different pre-treatments of biomass from palm oil waste

This study evaluates three pathways: supercritical water treatment (SCW), CO2-water (scCO2-H2O), and catalytic hydrothermal hydrolysis (CHH) to produce second-generation bioethanol using palm tree fronds (PTF) as feedstock. The analysis focuses on technical performances using process simulation with Aspen Plus™, environmental evaluation by applying a Life Cycle Assessment (LCA) framework and an economic analysis using the levelized cost. The results of the technical performances reveal CHH as the best pathway for bioethanol production, with the highest ethanol yield at 273 L/tonne dry PTF and a substantial NER of 2.2, outperforming SCW and scCO2-H2O. From an environmental evaluation, CHH reveals lower carbon footprints of 61 g CO2 per MJ. Economically, CHH is competitive, with an ethanol production cost of1.11 $/L, comparable to the enzymatic hydrolysis process. These findings provide the technical, environmental, and economic aspects of a promising route for lignocellulosic bioethanol production while suggesting pathways for further optimisation for future research.

Enhancing life cycle assessment framework to support product ecodesign through index decomposition analysis

In ecodesign, life cycle assessment (LCA) has not only been used to evaluate a product's environmental sustainability but also serves as a tool for designers to identify areas for sustainability improvement. Conventionally, this is achieved by ranking all contributing LCA variables to identify high-impact areas. However, interpreting and translating this information into actionable design variables can be challenging. An LCA variable can be influenced by multiple design variables, each of which might affect the design's environmental sustainability to varying degrees. Presently, there is a lack of tools capable of analysing the influence of each design variable. To bridge this gap, this study proposes an LCA disaggregation methodology that uses Index Decomposition Analysis (IDA) to assess the environmental sustainability significance of the considered design variables. Using the methodology, designers can make informed decisions that prioritise design effort on design variable with the greatest potential for enhancing the product's environmental sustainability. The proposed methodology is demonstrated through a case study involving the design of a desk fan cover, considering material choice, geometry, and manufacturing process as key design variables.

Comparative life cycle assessment of flooring options for sustainable buildings

Purpose This study aims to quantify and compare the environmental impacts of Marble-stone and Kota-stone flooring options widely used for buildings in India. The study discusses the possibility of carbon sequestration through Bamboo cultivation in India. Design/methodology/approach The study has followed a standard life cycle assessment (LCA) framework based on ISO 14040 guidelines. Three distinct phases have been compared on midpoint and endpoint assessment categories – raw material, polishing and disposal. Primary data has been collected from the construction site in India, and secondary data has been collected from the Ecoinvent 3.0 database. Previous studies have been referred to discuss and calculate the area of bamboo cultivation required to sequestrate the generated carbon from the flooring. Findings The study has found that endpoint category damage to resources, and midpoint categories of climate change, metal depletion and agricultural land use are highly impacted in building floorings. The study has also found that the Marble-stone floor generates higher environmental impacts than the Kota-stone floor in most of the midpoint and endpoint impact categories. This difference is significant in the raw material phase due to the different compositions of stones. The study also found that Bamboo has excellent potential to act as a carbon sink and mitigate the generated carbon. Research limitations/implications This study excludes human labour, cutting and distribution of floor tiles made of Marble-stone and Kota-stone. The researcher can use the study to evaluate, compare and benchmark the various building flooring options from the environmental perspective. The study aids to the body of knowledge available on the various building flooring options by presenting the LCA or the environmental impacts generated by two flooring options. It is expected that the architects and builders can use these results to develop carbon-neutral buildings. This study provides a methodology for governments, constructors, builders and individuals to evaluate, compare and benchmark the various construction materials from the environmental perspective by computing the environmental impacts throughout the life cycle of the materials. Originality/value This study compares two widely used building flooring options using the LCA methodology and evaluates the potential of bamboo cultivation near the buildings for carbon sinks. The study is unique because it shows the environmental impacts of two flooring options and the carbon sequestration method to mitigate/absorb the generated environmental impacts in or around the building itself through bamboo cultivation. This study may set the foundation for carbon-neutral buildings.

Carbon emissions quantification and different models comparison throughout the life cycle of asphalt pavements

Establishing a comprehensive and systematic method for quantifying carbon emissions (CEs) of asphalt pavement is challenging due to the multifaceted and diverse nature of the involved processes. Utilizing a life cycle assessment framework, this study introduces a practical model system for capturing CEs across the entire lifespan of asphalt pavement. A pivotal aspect of our approach involves calculating activity levels. Material quantities are ascertained based on mixture proportions and specific pavement information. We employ Ridge Regression and the quota method to approximate the energy consumption of construction machinery. A comparative analysis is performed between two CE computation models that use energy consumption and operational time as activity levels, respectively. Additional vehicle fuel consumption is translated based on shifts in the International Roughness Index, as predicted by the Mechanistic-Empirical Pavement Design Guide. CEs from traffic disruptions are calculated collaboratively through VISSIM simulations and MOVES emission modeling. Our findings reveal that material production, mixture preparation, and maintenance duration are the principal factors contributing to CEs throughout the asphalt pavement lifecycle. Notably, emission estimates for machinery in the construction phase can vary by as much as 8.3 times across different models. The study suggests that incorporating the use of recyclable materials and designing more durable pavement structures can offer effective avenues for CE mitigation.