Life Cycle Assessment Indicators Research Articles

Environmental impacts as the key objectives for perovskite solar cells optimization

With perovskite solar cell (PSC) performance already touching the limits of single junction PV devices, the major challenges have now shifted to upscaling and stability. A plethora of materials and processes have been used for making perovskite solar cells/modules in order to tackle these challenges. However, it is important to see the impact of these decision variables not only on the cost and efficiency of the final cells but also on their environmental footprint. In this work, the analysis of these different options of technologies and materials on the final environmental footprint using a cradle-to-gate life cycle assessment (LCA) approach is carried out and uncertainty with respect to these options is discussed in detail in order to gain insights into more optimal designs of perovskite solar cells. A comparison of the possible range of environmental impact indicators for perovskite solar modules with existing mature PV technologies is also presented to highlight the future prospects of perovskite solar technology in providing more eco-friendly and sustainable energy solutions. The results indicate that on average PSCs are not considerably better than existing PV technologies and show the possibility of optimizing PSCs with respect to different LCA indicators.

Guidelines on the selection and inventory of social life cycle assessment indicators: a case study on flexible plastic packaging in the European circular economy

Abstract Purpose Emerging technologies are addressing current challenges to shift from a linear to a circular economy. However, the consideration of social aspects in this context is limited, and the prioritization of indicators appears arbitrary in the absence of clear and robust selection criteria. Following social life cycle assessment (S-LCA) principles, the aim of this paper is to guide the selection and inventory of social indicators based on a case study on evolving flexible packaging within the European circular economy. Methods To achieve the objective, the study involves several steps, including conducting a systematic literature review to identify key stakeholders, impact subcategories, indicators, and inventories for circular flexible plastic packaging. Multi-criteria decision analysis (MCDA) is applied to preselect a set of indicators, followed by stakeholder engagement in prioritizing impact indicators through participatory methods. Subsequently, a data collection procedure was established. Results and discussion This paper presents a materiality ranking for 19 social indicators tailored to the emerging circular flexible packaging. The result is a prioritization of nine of these indicators, including Existence of record of proof of age, Percentage of workers who are paid a living wage or above, and Existence of certified environmental management system. These nine indicators form the basis for the collection of respective inventory data for an entry-level assessment. Furthermore, guidelines on 11 procedural steps were formulated based on these findings. Moreover, challenges of synonymity and inconsistency in S-LCA terminology, besides inaccessible inventory data especially in the context of evolving recycling technologies, are identified as substantial barriers in the effort to streamline and perform S-LCA. Conclusions The paper concludes that prioritizing indicators is essential for entry-level and prospective assessments, especially when time and data are limited. Additionally, using primary inventory data to evaluate the foreground system and its direct impacts on stakeholders promotes accountability and corporate social responsibility. Furthermore, a set of procedural steps, from defining the system boundary to preparing the data questionnaire, serves as a valuable resource for practitioners across diverse industries. Recommendations In future research, these nine prioritized indicators can be applied to assess the social performance of various case studies along the value chain of circular flexible plastic packaging, covering food and non-food applications. In addition, the methodological guidelines for selecting and prioritizing indicators can be replicated across multiple industry sectors. Moreover, research effort should be directed towards establishing a methodological framework for prospective S-LCA in the context of emerging technologies.

External Wall Systems in Passive House Standard: Material, Thermal and Environmental LCA Analysis

The construction sector, a significant consumer of energy, possesses the potential to realize substantial environmental and economic advantages through the adoption of innovative technologies and design approaches. Notably, the Passive House standard, exemplified by energy-efficient single-family homes, emerges as a prominent solution. This study analyzes five external wall systems across multiple stages: (i) a literature review and examination of external wall techniques within the passive standard, utilizing the Passive House Database; (ii) a material and technological assessment of three wood-based and two masonry constructions; (iii) an in-depth thermal performance analysis of selected external partitions; and (iv) a Life Cycle Assessment (LCA) of the external wall systems. Our findings indicate that among the single-family homes built to the passive standard, 50.94% utilized timber constructions, while 34.21% employed masonry. Thermal analysis revealed that the masonry wall, EW-M-01, exhibited superior thermal efficiency with a heat transfer coefficient (U-value) of 0.0889 W/m2K. Meanwhile, the wooden wall, EW-T-01, led its category with a U-value of 0.1000 W/m2K. The LCA highlighted that the wooden wall EW-T-02 presented the lowest integrated non-renewable energy demand (PENTR) at 425.70 MJ/kg and the most favorable Global Warming Potential (GWP), with a reduction of 55.51 kg CO2e. Conversely, the masonry wall EW-M-01 recorded the highest energy demand and CO2e emissions, at 780.96 MJ/kg and 90.59 kg CO2e, respectively. Water consumption was lowest for the EW-T-02 wooden wall (0.08 m3) and highest for the EW-M-02 masonry wall (0.19 m3). Conclusively, our analysis of passive house external walls demonstrates that wood-based systems offer superior performance in terms of materials, thermal efficiency, and LCA indicators, positioning them as the preferred option for sustainable passive construction.

From LCA to circular design: A comparative study of digital tools for the built environment

This paper reviews digital tools for supporting the Circular Economy (CE) in the built environment. The study provides a bibliometric analysis and focuses on computer-aided design (CAD), building information modeling (BIM), and computational plugins that can be used by practitioners. While Life Cycle Assessment (LCA) is the primary methodology for evaluating buildings' environmental performance, the study identifies tools beyond LCA, including computational methods and circularity indicators, that can support the evaluation of circular design strategies. Our review highlights limitations in tools’ functionalities, including a lack of representative data for LCA and underdeveloped circularity indicators. The paper calls for further development of these tools in terms of interoperability aspects, integration of more sources of data for LCA and circularity, and possibilities for a comprehensive evaluation of design choices. Computational plugins offer greater flexibility, while BIM-LCA integrations have the potential to replace dedicated LCA software and spreadsheets. Additionally, the study identifies opportunities for novel digital methods, such as algorithms for circular design with various types of reused building elements, and sharing of digital twins and material passports. This research can inform future studies and support architects and engineers in their efforts to create a sustainable built environment.

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.

Investigating the Effects of Concrete Mix Design on the Environmental Impacts of Reinforced Concrete Structures

This study examines the impact of mix design parameters on the environmental effects of producing concrete and reinforced concrete buildings by conducting a life cycle assessment (LCA) and carbon footprint analysis (CFA). The study is limited to the cradle-to-gate phase, including the extraction and production of raw materials for concrete production, as well as concrete and rebar production, material transportation, and delivery to the construction site for reinforced concrete structures. Three concrete mix designs based on the American Concrete Institute (ACI) 211-09 standard, with compressive strengths of 20, 30, and 40 MPa, were analyzed. The results indicate that cement was the primary contributor to environmental impacts, accounting for approximately 90% of the carbon footprint. Sand, gravel, and admixtures followed cement in their impact on LCA results. Water usage in concrete production had a negligible effect on LCA indicators. Moreover, to determine how mix design parameters impact the carbon footprint of reinforced concrete buildings, three four-story structures were designed. The results show that in reinforced concrete buildings, concrete was a significant contributor to environmental impacts, accounting for over 50% of all indicators in the IMPACT 2002+ and CML baseline 2000 methods, except for resources and acidification. The study underscores the importance of considering mix design parameters in reducing the carbon footprint of reinforced concrete buildings and provides valuable insights into their environmental impacts. The findings indicate that cement is the main driver of environmental impacts in both assessment methods, accounting for around 90% of the carbon footprint. Additionally, concrete plays a substantial role in environmental effects, contributing to over 50% of all indicators measured in the methods used for evaluating environmental impacts.

Life cycle assessment and process optimization for polypropylene off-gas membrane separation

Life cycle assessment (LCA) was conducted on a polypropylene off-gas membrane separation process in China considering environment, energy and economy (3E) aspects. Two coupled indicators, I and SI were constructed based on LCA indicators. Process simulation was introduced to optimize flows and parameters. LCA results revealed that utility consumption and flare gas emission accounted for above 99% of environmental and energy impacts, but when integrating economic impact, the two factors would account for below 50%. Optimization results showed the single-objective optimization led to a trade-off of different indicators and the SI could achieve a more comprehensive optimization for the process.

Sizing a hybrid hydrogen production plant including life cycle assessment indicators by combining NSGA-III and principal component analysis (PCA)

In the design and synthesis of energy systems, mathematical tools such as optimization algorithms are often used. While using them, environmental indicators are increasingly used as optimization criteria to exploit the possible environmental benefits of these systems. The problem is that the high number of environmental indicators poses a problem for optimization algorithms in terms of convergence, computational time and visualization. In this paper, this problem is addressed through a many-objective search of solutions using a state-of-the-art evolutionary algorithm, NSGA-III. Furthermore, the performance of this algorithm is tested using different settings in the PCA-based objective reduction framework. The original 14 indicators are reduced to seven, four, three and two, which reveal important insights about the use of NSGA-III, objective reduction and a combination of the two. It was found that by using objective reduction, the performance of NSGA-III can be further improved in terms of the quality of solutions and computational time. However, beyond a certain point, further objective reduction leads to a trade-off between solution quality and computational time. For this case study, the best quality solutions were obtained in the PCA reduction procedure when the CUT value was maintained at 99.99% without additional reduction in the last step, using a correlation matrix. The algorithms were applied to a real-life sizing case study involving hydrogen production from polymer-electrolyte-membrane (PEM) water electrolysis, for which the demand is furnished by the electricity spot market, solar photovoltaics (PV) or wind turbine in Marseille, France. These results will be useful for future applications of many-objective optimization and objective reduction. They will also be practical for including environmental indicators in the many-objective search for solutions.

A critical review of urban scale life cycle assessment of the built environment

Considering that cities are responsible for a considerable share of energy consumption and GHG emissions, a complete environmental life cycle assessment (LCA) on an urban scale is gaining importance. This has led to numerous studies in this field of research, ranging from environmental impact investigation of building components (walls, insulation layers) to the carbon emission analysis of several buildings and networks, open spaces, and transportation facilities on a broader scale. This study aims to contribute to the field of research by conducting a comprehensive analysis of existing literature studies on varying scales. The primary objective is to determine whether the current studies have adequately addressed the gap in knowledge by effectively implementing Life Cycle Assessment (LCA) methodologies throughout the entire lifecycle of buildings while ensuring a sufficient level of detail and reliability in their findings. Additionally, this investigation seeks to evaluate the extent to which urban-scale LCA analyses have been undertaken in previous literature and assess the accuracy of the corresponding results. Furthermore, the study intends to identify the necessary measures that can be implemented to enhance the value and validity of these research outcomes. Ultimately, the findings of this research endeavor will identify the shortcomings and gaps in the current body of knowledge, thereby facilitating the development of a roadmap for future studies in this field of research. The gap analysis of this research field reveals important findings. Firstly, only 9% of previous studies have examined the entire urban scale, highlighting a significant research gap that should be addressed in future studies. Secondly, the bottom-up approach used in many studies introduces substantial uncertainty, necessitating improved modeling and uncertainty analysis. Thirdly, the building-by-building approach, while comprehensive, is time-consuming and costly, calling for research on enhancing its efficiency. Additionally, future studies should consider stock evolution beyond buildings, incorporate multiple LCA indicators, and integrate LCA with life cycle costing (LCC) in urban scale assessments. These identified gaps present promising avenues for future research in built environment LCA.

Using LCA and Circularity Indicators to Measure the Sustainability of Textiles—Examples of Renewable and Non-Renewable Fibres

Reducing environmental impacts by increasing circularity is highly relevant to the textiles sector. Here, we examine results from life cycle assessment (LCA) and circularity indicators applied to renewable and non-renewable fibres to evaluate the synergies between the two approaches for improving sustainability assessment of textiles. Using LCA, impacts were quantified for sweaters made from fossil feedstock-derived and bio-based PET. These same sweaters were scored using four circularity indicators. Both sweaters showed similar fossil energy footprints, but the bio-PET raw material acquisition stage greenhouse gas, water and land occupation impacts were 1.9 to 60 times higher, leading to higher full life cycle impacts. These contrasts were principally determined by what raw material acquisition processes were considered outside the system boundary of the alternative feedstocks. Using circularity indicators, fossil-feedstock PET scored lowest (worst) because the feedstock was from a non-renewable source. These examples highlight the limitations of LCA: the renewability or non-renewability of raw materials is not fully considered, and contrasts in processes included within system boundaries can preclude equitable comparisons. For LCA to be suitable for quantifying sustainability, it should be complemented by circularity indicators capable of demonstrating the contrast between renewable and non-renewable raw materials, particularly in the case of textiles.

Integrated Sustainability Assessment: Exergy, Emergy, Life Cycle Assessment

Methodological tools such as Life Cycle Assessment (LCA), Exergy Analysis (ExA), and Emergy Analysis (EmA) that account for sustainability indicators in environmental, economic, and/or social dimensions, cannot provide an assessment under these three dimensions in a robust way by themselves. This research is proposing a sustainability assessment framework to obtain a unified performance metric (Integrated Sustainability Index, ISI) to assess the Triple Bottom Line – TBL. LCA, ExA, and EmA indicators are implemented in a complementary but not interchangeable manner, providing additional information for sustainability decision-making. The systematic approach is on a conceptual definition and calculation of sustainable environmental, social, and economic disaggregated indicators. These are then systematically combined into an Integrated Sustainability Index (ISI). EmA evaluates sustainability from a “donor-side” perspective, by assigning values to the environmental efforts and investment of nature to make and support flows, materials, and services; the system boundary is the geosphere. ExA evaluates sustainability through exergy efficiency under a “user-side” evaluation process (system boundary is the technosphere). LCA evaluates it based on the quantification of environmental impact by water, soil, and air emissions, caused by the use and processing of resources to provide products or services as a “user-side” method. The proposed sustainability index presents a comprehensible hierarchic structure supported by LCA, ExA, and EmA methodologies. The integration of social, environmental, and economic components into an index that also allows for the adjustment of externalities reducing the risk of subjectivity is a new approach to assessing sustainability.

Life cycle assessment of power-to-methane systems with CO2 supplied by the chemical looping combustion of biomass

Power-to-methane (PtM) systems may allow fluctuations in the renewable energy supply to be smoothed out by storing surplus energy in the form of methane. These systems work by combining the hydrogen produced by electrolysis with carbon dioxide from different sources to produce methane via the Sabatier reaction.The present work studies PtM systems based on the CO2 supplied by the chemical looping combustion (CLC) of biomass (PtM-bioCLC). Life- cycle- assessment (LCA) was performed on PtM-bioCLC systems to evaluate their environmental impact with respect to a specific reference case. The proposed configurations have the potential to reduce the value of the global warming potential (GWP) climate change indicator to the lowest values reported in the literature to date. Moreover, the possibility of effectively removing CO2 from the atmosphere through the concept of CO2 negative emissions was also assessed. In addition to GWP, as many as 16 LCA indicators were also evaluated and their values for the studied PtM-bioCLC systems were found to be similar to those of the reference case considered or even significantly lower in such categories as resource use-depletion, ozone depletion, human health, acidification potential and eutrophication. The results obtained highlight the potential of these newly proposed PtM schemes.

Intercropping Practices in Mediterranean Mandarin Orchards from an Environmental and Economic Perspective

Crop diversification is becoming increasingly important for preserving soil and ecosystems’ health and, subsequently, crop productivity and sustainability. Intercropping practices adopted in monocultural woody crops, with herbaceous crops covering the otherwise bare alleyways, foster ecological interactions and can provide both environmental and economic advantages. In this study, intercropping practices were implemented in a traditional mandarin orchard in south-eastern Spain, which was monitored for three years to assess their impact on the environmental footprint and profitability. The footprint was quantified with a cradle-to-gate life cycle assessment (LCA), while the costs and revenues assessment was based on materials, labor, and machinery used in the trial. The calculated LCA indicators evidenced that, although the cultivated surface area increases with the integration of the intercrops (fava bean, purslane, cowpea, and barley/vetch mix), this does not imply any additional detrimental effects (resource depletion, acidification, eutrophication, global warming). The economic analysis showed that while intercrops may involve additional production costs, the correct choice of intercrops, purslane, and fava bean, in this case, can reduce the market risks for farmers. Overall, this study shows that positive environmental and economic impacts are to be expected of co-integrated herbaceous crops within the same field as mandarin trees.

The Consumption Footprint as possible indicator for environmental impact evaluation at city level. The case study of Turin (Italy)

Environmental assessment methods have increasingly been adopted to support local transitions toward sustainable urban development and Agenda 2030 implementation at the city level. However, available methods evaluating both direct and indirect (embodied) environmental impacts due to local consumption are still limited and lack a broad coverage of environmental issues. Adopting a Life Cycle Assessment (LCA) perspective in current approaches may help to fill this gap. In this paper, we evaluated the environmental impacts associated to consumption patterns and intensities of the average Turin citizen (Italy) by implementing the LCA-based Consumption Footprint indicator, which assesses the impacts of five areas of consumption (food, mobility, housing, household goods, appliances) with the 16 impact categories of the Environmental Footprint method. Comparing Turin and EU consumption patterns, the average Turin citizen showed a larger impact on human toxicity (+30%) and a lower on ozone depletion (-21%) with housing, food, and mobility as main drivers. This represents a first attempt in assessing local consumption with full bottom-up LCA indicators. The Consumption Footprint allowed unveiling local consumption trends while connecting them to a global dimension of impacts (e.g., Planetary Boundaries). Main challenges include input data types (e.g., local consumption intensities) and coverage of consumer goods modelled via the proposed indicators.

Nexus Between Life Cycle Assessment, Circularity, and Sustainability Indicators—Part I: a Review

Circular economy (CE) and sustainable development are not systematically synonyms and some trade-offs might occur between circularity and sustainability. This study addresses the nexus—i.e., the potential concurrence, complementarity, or conflict—between circularity and sustainability indicators to develop and monitor more circular and sustainable systems, using two complementary research approaches: (i) a review and comparison of existing works covering circularity and sustainability performances concurrently (Part I), (ii) new experimentations on more circularity and sustainability to fill the gaps of previous works and bring more concrete insights for practitioners on this matter (Part II). In the present Part I, we provide a state-of-the-art summary of the solutions and challenges related to the measurement of the sustainability performance of CE strategies. The contributions and limitations of life cycle assessment (LCA), leading sustainability, and circularity indicator–based approaches are analyzed, compared, and illustrated. Ten independent studies experimenting and comparing LCA and circularity indicators on different products are analyzed and compared. Depending on the product context and the CE scenarios evaluated, several types of connections emerged: beneficial, conditional, or scenario-dependent trade-offs. To fill the gaps of the existing studies exposed at the end of this paper (Part I), a new set of experimentations is designed and conducted (Part II) to further understand how these different approaches and indicators could be appropriately deployed to develop more circular and sustainable product systems.

Combining circular and LCA indicators for the early design of urban projects

The built environment is a key sector for the transition towards a so-called circular economy, contributing to solve the global environmental challenges humanity is facing. As buildings interact with other sectors like transport and energy, a systemic approach is needed to assess the environmental relevance of circular economy practices. The purpose of this study is to develop and test an approach for the evaluation of overall environmental performance of urban projects. Combining Material Flow Analysis (MFA), the Material Circularity Indicator (MCI), and Life Cycle Assessment (LCA) indicators allows for relating means (material recovery) and performance (protection of human health, biodiversity, and resources). This study shows the ability of LCA to evaluate circular economy practices at the scale of an urban project. It also highlights LCA’s limitations and shows that research is needed to improve resource depletion evaluation and biogenic carbon accounting in eco-design LCA tools. Results show that at the project scale, the MCI, one of the major circular indicators in use today, and MFA provide interesting information complementary to LCA but do not successfully evaluate the environmental performance of circular practices. Circularity indicators are complementary to LCA indicators and should not replace them in the eco-design process. Rather than setting circularity targets for a project, it is advisable to set environmental targets so that designers use circularity combined with other means to reach these targets in a systemic way. The choice and implementation of environmentally sound circular actions and strategies are at stake.

Sizing a Hybrid Hydrogen Production Plant Including Life Cycle Assessment Indicators by Combining Nsgaiii and Principal Component Analysis (Pca)

Sizing a Hybrid Hydrogen Production Plant Including Life Cycle Assessment Indicators by Combining Nsgaiii and Principal Component Analysis (Pca)

Environmental Sustainability Assessment of Pig Farms in Selected European Countries: Combining LCA and Key Performance Indicators for Biodiversity Assessment

The aim of this study was to combine Life Cycle Assessment (LCA) with a Key Performance Indicator (KPI) assessment focusing on biodiversity in order to examine the environmental impacts of different pig farm types (13 breeding, 23 finishing and 27 breeding-to-finishing farms) in seven European countries. In addition, the relationship between environmental impacts and selected farm management characteristics was explored. Fossil energy depletion (FED), global warming (GWP), acidification (AP) as well as marine (MEP) and fresh water (FEP) eutrophication potential were assessed by an attributional LCA and expressed per kilogram body mass net sold (BMNS). In addition, the potential biodiversity performance of all crop-livestock farms within the sample (n = 56) was evaluated with a KPI assessment of biodiversity-related field management characteristics. We found no relationship between LCA results and biodiversity scores (KPI). LCA and biodiversity performance varied more within than across farm types (breeding, finishing, breeding-to-finishing). For example, the GWP expressed per kg BMNS of the breeding unit of breeding-to-finishing farms was on average (median) 2.77 (range: 1.40–4.78) and of breeding farms 2.57 (range: 1.91–3.23) kg CO2-eq. The average (median) biodiversity theme score for breeding farms was 51% (range: 36–70%), for breeding-to-finishing farms 38% (range: 30–68%) and for finishing farms 43% (range: 28–67%). Several farm management characteristics (e.g., FCR, productivity, proportion of solid manure) correlated with all/some LCA results. Biodiversity performance depended especially on KPIs related to ecological focus areas, fertiliser management and GMO crops. The large range regarding environmental performance in both LCA and KPI assessment across farm types indicates that farm-specific improvement measures should be implemented to enhance overall environmental sustainability on farm. In conclusion, combining LCA with KPI assessment provides a more comprehensive environmental impact assessment of pig farms.

Holistic approach in the evaluation of the sustainability of bio-based products: An Integrated Assessment Tool

The capacity to demonstrate the sustainability of bio-based products is crucial for promoting the full deployment of a circular bio-based economy, and for boosting new products’ market uptake. Hence, there is a growing need to deliver methodological guidance to companies on assessing the sustainability of their innovative and claimed sustainable bio-based products. In this regards, the present article proposes a tool for assessing the sustainability of bio-based products, addressing the most relevant sustainability aspects (i.e. environmental, social, economic and circular) from a life cycle perspective. The proposed integrated assessment tool (IAT) is the result of a transdisciplinary process involving contributions from both industry and academia. To this end, the research involved numerous repeat interactions with practitioners and researchers to guide the selection of relevant areas of sustainability protection and related indicators and metrics, for ultimate inclusion in the tool. Multi-stakeholder workshops, webinars and expert interviews were also employed in the development of the tool´s functional elements (i.e. data collection, scoring, communication). The resulting tool consists of 48 sustainability indicators with proposed metrics based on existing standards, methodologies and best practices in sustainability assessment. The tool scoring system allows users to compare the performance of their bio-based product to an “ideal”. A key finding of the research is that, to produce a complete and reliable sustainability assessment, effective collaboration between economic operators along the bio-based value chain is needed. Furthermore, overall sustainability performance, particularly with respect to the life cycle assessment indicators, are heavily influenced by the type of biomass and related agricultural practices. It is therefore recommended to employ the tool on a case by case basis, maximizing the use of primary data.

Evaluation of environmental effect of pump shoes in terms of manufacturing process

China is the largest footwear producing country, as well as the largest country producing the footwear manufacturing waste. In order to achieve sustainable development in the footwear industry, we should pay attention to their environmental effect seriously. Therefore, by applying life-cycle assessment (LCA) protocol, we aimed to explore the effect of the manufacturing process on the environment of a classical style of pump shoes. Following guidelines of ISO 14010, we first determined the objective and the scope of this study; then, we collected input and output data from the shoe producing line of a shoe-making enterprise in Wenzhou, China; afterwards, we applied eFootprint software for LCA modeling; finally, we chose three LCA indicators for further analysis: Global Warming Potential (GWP, kg CO2 eq), Primary Energy Demand (PED, MJ) and Abiotic Depletion Potential (ADP, kg Sb eq). Our results show that by producing one pair of pump shoes, the manufacturing process will emit 11.427 Kg CO2 eq in terms of GWP, 232.621MJ in PED and 6.291×10-5Kg sb eq in ADP. Hence, by multiplying the number of shoes produced in China, negative environmental influences from shoe making industry were also dramatic. According to further contribution rate of all process, we found that materials such as the water-based binder and the plastic last used in manufacturing process accounted for the major reason. Overall, while considering the environmental effects from the shoe manufacturing process, we shall not ignore the environmental impact whilst producing the binder and the last. Moreover, by reducing binder usage or updating the shoe making technology, and recycling the last can be an efficient way to reduce the environmental effects from the shoe making industry.