Screening Life Cycle Assessment Research Articles

Screening Life Cycle Assessment comparing One-step and Two-step Injection Molding Compounding using Conservative and Optimistic Scenarios

One-step injection molding compounding (IMC) is an innovative process to manufacture short-fiber-reinforced polymer composites. The aim of combining compounding and injection molding into one process is to enhance component quality and minimize environmental impacts. In this study, a screening Life Cycle Assessment (LCA) is conducted to evaluate and compare the environmental impacts of the IMC process with standard two-step manufacturing. Two scenarios for the IMC are considered, each differing in terms of machinery requirements, energy consumption, and material usage. Mechanically recycled polypropylene and glass fiber are used, and considered in the LCA employing a simple cut-off approach without awarding credits for substituting (primary) materials. The functional unit is the composite produced via the respective process, assuming equal functionality. Inventory data are obtained from initial experiments, literature, and the ecoinvent database. The impact assessment method selected is ReCiPe2016. Results indicate that the environmental performance improvement achieved by the IMC compared to the reference process is minimal in the conservative scenario where energy and material usage can be reduced but machinery usage is increased. However, in an optimistic scenario, the IMC can reduce the impacts of composite manufacturing by 34 %. The contributions at the midpoint level vary, and metal usage and energy consumption are the main contributors in all scenarios. A variation of the energy source for manufacturing shows the dependency of environmental impacts of components produced in both processes on the geographical location of production and its electricity supply. Methodological choices, such as the definition of the functional unit and modeling of recycled materials, have a large influence on LCA results, and alternative options are discussed.

Identification and Environmental Assessments for Different Scenarios of Repurposed Decommissioned Wind Turbine Blades

The rapidly growing wind industry poses a fundamental problem for wind turbine blade (WTB) disposal in many areas of the world. WTBs are primarily manufactured from composites consisting of a thermoset matrix and reinforcing fibers. Currently, there are no economically viable recycling technologies available for such large-scale composite products. Thus, other treatment strategies for disposed WTBs have to be considered. This study explores the repurpose of WTBs as a promising alternative approach from a processual and technological point of view. For this purpose, the study is guided by the categorization into four different types of repurposed applications: high-loaded complete structure (T1), low-loaded complete structure (T2), high-loaded segmented structure (T3), and low-loaded segmented structure (T4). A three-dimensional CAD model of an Enercon-40/500 (E40) wind turbine blade is derived in a reverse engineering procedure to obtain knowledge about the actual geometry of the WTB. Based on the design, three ecosystems of product scenarios (S) with different manufacturing technologies involved are investigated: a climbing tower (S1), a playground (S2) and the combination of a photovoltaic (PV)-floating pontoon, and a lounger (S3). A screening life cycle assessment (LCA) is conducted to evaluate the three repurposed scenarios according to environmental aspects. It is shown that the repurpose of E40 WTB composite material can reduce the environmental impact and leads to significant resource savings in relation to a reference product of similar quality. A particularly high saving potential is identified for the substitution of emission-intensive materials in construction applications. Furthermore, it is found that transport processes are the primary contributor to the environmental impact of repurposed applications.

Screening life cycle assessment of medical workwear and potential mitigation scenarios

This study presents a life cycle assessment of medical workwear, which is an essential type of clothing worn by millions of medical professionals worldwide. The study aims to identify the environmental hotspots and to assess potential reduction scenarios to support decision and policy-making.The study employs LCA as the chosen method to analyse the environmental impacts of five typical medical workwear garments: scrub top, scrub trousers, polo shirt, doctor's coat, and doctor's trousers. Additionally, ten reduction scenarios and sensitivity analyses on nine parameters are presented.For the majority of environmental impact categories, the use phase, particularly the washing of medical workwear, is the most important contributor. The assessment of potential reduction scenarios showed that actions on energy usage and material efficiency are the most effective. Combining several of these mitigation actions, environmental impacts can be reduced significantly, e.g. the global warming potential of the scrub top can be reduced by more than 70 % from 15.5 kg CO2eq to 4.1 kg CO2eq.The results help policy and decision makers in healthcare to consider environmental impacts in their decision-making and identify potential reduction actions. Laundry companies have a crucial role in reducing overall environmental impacts by using renewable energies, improving efficiency and increasing recycling.

Applying life cycle assessment with minimal information to support early-stage material selection

Traditional life cycle assessment (LCA) is too data intensive and time consuming to be used during typical building design processes. Conducting an LCA during the building design process therefore requires simplifications and assumptions. Such “screening LCAs” are quicker and can be used with less data but introduce greater uncertainty. Unfortunately, uncertainty is not reflected in standard deterministic LCA calculations, which produce single-point values in LCA results. Thus, in this study, data quality scoring has been incorporated into a screening LCA to produce probabilistic predictions of environmental performance based on limited data. The approach has been applied during the design process of a bio-based wall panel designed for a circular economy. A combination of ecoinvent and material data sheets were used to analyse a wide range of novel bio-based insulation materials. The screening LCA analysed global warming potential and identified a short-list of promising materials that were then subjected to a detailed LCA for further consideration in the design. The method uses publicly available information and can be applied at material or building-element level. The method thus helps designers estimate environmental impacts without hindering the design process.

Economic and environmental life cycle assessment of a short-span aluminium composite bridge deck in Canada

The costs to maintain Québec's infrastructure—most of which was built in the 1960s and 1970s—are considerable, and major maintenance and reconstruction will be required in the coming years. In recent years, aluminum associations promote the increase of aluminum use in infrastructure and especially in bridge construction. This research aims to investigate the advantages of using aluminum deck bridges, which require less maintenance than traditional materials due to the natural resistance to atmospheric corrosion of aluminum, despite their higher investment costs that may limit their deployment. More specifically, the study compares for the first time the life cycle costs and environmental impacts of an aluminum-steel composite deck with a more traditional concrete-steel composite deck and provides a parametrized model allowing practitioners and designers to perform screening life cycle assessment and cost of short span bridge based on our data and results. Results show that the initial cost of aluminum deck is double that of concrete deck, but the overall cost is actually four times lower over the entire life cycle. The environmental results demonstrate the benefits of aluminum deck. Our main recommendation for future decision making in road infrastructure management is therefore to systematically expand the scope of the analysis integrating a full life cycle thinking also including the effects from traffic diversion.

Screening Life Cycle Assessment of Tall Oil-Based Polyols Suitable for Rigid Polyurethane Foams

A screening Life Cycle Assessment (LCA) of tall oil-based bio-polyols suitable for rigid polyurethane (PU) foams has been carried out. The goal was to identify the hot-spots and data gaps. The system under investigation is three different tall oil fatty acids (TOFA)-based bio-polyol synthesis with a cradle-to-gate approach, from the production of raw materials to the synthesis of TOFA based bio-polyols at a pilot-scale reactor. The synthesis steps that give the most significant environmental footprint hot-spots were identified. The results showed the bio-based feedstock was the main environmental hot-spot in the bio-polyol production process. Future research directions have been highlighted.

Screening Life Cycle Assessment to compare CO2 and Greenhouse Gases emissions of air, road, and rail transport: An exploratory study

Abstract Given the large contribution of the transport sector in the global level of Greenhouse Gases (GHG) emissions, developing and adopting more carbon-efficient transport mode is crucial. Many discrepancies exist in the literature comparing modal transport emissions since their scope, geographic perimeter, calculation methods and sets of assumptions strongly vary. This paper reviews some CO2 and GHG emissions data from the literature analyzing air, road, and rail transport, and shows that similar patterns of contributors can be found within each mode. It allows the identification of some important parameters to focus on for further development of multimodal comparative Life Cycle Assessments.

Life cycle assessment of innovative circular business models for modern cloth diapers

Brazil, an emerging economy with more than 208 million inhabitants, is currently one of the biggest consumers of disposable diapers worldwide, generating huge waste streams to sanitary landfills or dumps. This take-make-dispose system causes high material and fuel consumption and serious environmental impacts. The concept of the Circular Economy, promoting that material flows should be circular, material and energy efficiency should be maximized and residues, as far as possible, designed out, has continuously gained attention over the last decade. For a Circular Economy, technological innovation, new business models and changes in consumer behavior are needed. The present study compares the use of modern cloth diapers and disposable diapers via a screening Life Cycle Assessment, checking conventional and innovative circular business models for the application of modern cloth diapers, such as the leasing or pay-per-service models, while focusing on the regional context of Brazil. Results indicate that cloth diapers show generally a better environmental performance than disposable diapers, whose poor performance is mainly due to their end-of-life treatment in sanitary or unsanitary landfill, provoking high greenhouse gas emissions. For cloth diapers, the most advantageous product system consists in a diaper-as-service model at large scale, using efficient continuous batch washers for sanitizing the diapers. Diaper-as-service models at smaller scale in so-called on-premise laundries show poorer environmental performance, due to higher water and energy needs. Domestic laundering of diapers is a good alternative regarding its environmental performance, because of its low energy consumption. However, consumers accustomed with disposable diapers might be reluctant to engage with this additional domestic labor.

Development of LCA benchmarks for Austrian torrent control structures

PurposeThis study emerged from a research project that aimed to develop a Life Cycle Assessment (LCA) model for torrent control structures. This publication constitutes the last part of model development and shows the LCA results of the examined structure types considering the entire life cycle. These LCA results will be used in a further step to close the environmental knowledge gap within the area of sustainability assessment. The sustainability assessment of buildings is already widespread and standardised in Green Building Rating Systems (GBRSs), which use LCA benchmarks for the rating of environmental indicators. The development of GBRSs for infrastructure is somewhat younger than the developements in the building sector and the existing systems do not yet provide LCA benchmarks for the environmental rating of the structures. The study shows how to derive benchmarks from the LCA results and thus gives a quantitative basis for a future rating of environmental indicators of torrent control structures.MethodsThe methodological basics for the LCA of torrent control structures were created by screening LCAs of several construction projects. From these construction projects, different structure types could be identified and classified. Functional units were developed, which can be assigned to the structure types. Uncertainties arise because these structure types are not always built in the same way. It can be distinguished between five uncertainties. Uncertainties of material dataset modeling, variable material use and machine use have been identified. Furthermore, the variable material use influences the emissions of transport. The transport in turn demonstrates uncertainties in the transport distances. Last but not least, there are variable service life times that dictate the replacement cycles of the structures. LCA benchmarks can be derived by the elevation of the various uncertainty distributions and its application in a Monte Carlo simulation.Results and discussionBy applying the method described above, it was possible to develop LCA benchmarks for different types of torrent control structures. These benchmarks show the range of LCA results for these structures. Furthermore, a sensitivity and uncertainty contribution analysis was carried out to investigate dependencies.ConclusionsBy determining the range of LCA results, an estimate of environmental impacts in early planning stages becomes possible. Furthermore, this allows decision-making in early planning stages and throughout the entire life cycle of the structures, taking into account environmental impacts. A further development of the benchmarks requires the analysis of additional structures to increase the accuracy and to reduce parameter uncertainties.

On the Theoretical CO2 Sequestration Potential of Pervious Concrete

Pervious concrete, which has recently found new applications in buildings, is both energy- and carbon-intensive to manufacture. However, similar to normal concrete, some of the initial CO2 emissions associated with pervious concrete can be sequestered through a process known as carbonation. In this work, the theoretical formulation and application of a mathematical model for estimating the carbon dioxide (CO2) sequestration potential of pervious concrete is presented. Using principles of cement and carbonation chemistry, the model related mixture proportions of pervious concretes to their theoretical in situ CO2 sequestration potential. The model was subsequently employed in a screening life cycle assessment (LCA) to quantify the percentage of recoverable CO2 emissions—namely, the ratio of in situ sequesterable CO2 to initial cradle-to-gate CO2 emissions—for common pervious concrete mixtures. Results suggest that natural carbonation can recover up to 12% of initial CO2 emissions and that CO2 sequestration potential is maximized for pervious concrete mixtures with (i) lower water-to-cement ratios, (ii) higher compressive strengths, (iii) lower porosities, and (iv) lower hydraulic conductivities. However, LCA results elucidate that mixtures with maximum CO2 sequestration potential (i.e., mixtures with high cement contents and CO2 recoverability) emit more CO2 from a net-emissions perspective, despite their enhanced in situ CO2 sequestration potential.

Screening Life Cycle Assessment of beneficiation processes for Rare Earth Elements recovery from secondary sources

Rare Earth Elements (REEs) are identified as critical raw materials for the EU economy. The ENVIREE project aims at contributing to REE supply in Europe, by addressing the exploitation of tailings and mining waste. Two secondary sources: tailings from New Kankberg (Sweden) and Covas (Portugal) are promising and rich in REEs. Beneficiation is one of the main step of REE recovery from secondary sources. The aim of this paper is to report the Life Cycle Assessment modelling with SimaPro software of beneficiation processes developed for tailings from New Kankberg and Covas. For the REE concentrate production from New Kankberg tailings, which come from an operating gold production plant, the highest environmental impact is caused by the disposal of the final residues after beneficiation. For the REE concentrate production from Covas tailings, which represent 30 years underground mining activity focused in tungsten, the highest environmental impact is caused by the electricity consumption for gravity and magnetic separation.

LiSET: A Framework for Early‐Stage Life Cycle Screening of Emerging Technologies

SummaryWhile life cycle assessment (LCA) is a tool often used to evaluate the environmental impacts of products and technologies, the amount of data required to perform such studies make the evaluation of emerging technologies using the conventional LCA approach challenging. The development paradox is such that the inputs from a comprehensive environmental assessment has the greatest effect early in the development phase, and yet the data required to perform such an assessment are generally lacking until it is too late. Previous attempts to formalize strategies for performing streamlined or screening LCAs were made in the late 1990s and early 2000s, mostly to rapidly compare the environmental performance of product design candidates. These strategies lack the transparency and consistency required for the environmental screening of large numbers of early‐development candidates, for which data are even sparser. We propose the Lifecycle Screening of Emerging Technologies method (LiSET). LiSET is an adaptable screening‐to‐LCA method that uses the available data to systematically and transparently evaluate the environmental performance of technologies at low readiness levels. Iterations follow technological development and allow a progression to a full LCA if desired. In early iterations, LiSET presents results in a matrix structure combined with a “traffic light” color grading system. This format inherently communicates the high uncertainty of analysis at this stage and presents numerous environmental aspects assessed. LiSET takes advantage of a decomposition analysis and data not traditionally used in LCAs to gain insight to the life cycle impacts and ensure that the most environmentally sustainable technologies are adopted.

Screening LCA of torrent control structures in Austria

PurposeThe purpose of this article is to find a suitable life cycle assessment (LCA) method to quantify the most important environmental burdens caused by construction processes of torrent control structures. To find these environmental burdens, 17 construction projects of the “Austrian Service for Torrent and Avalanche Control” (WLV) were analyzed using the “cradle to gate with options” LCA methodology (CEN, 2013).MethodsThis article explains an LCA methodology for the product stage and the construction process of torrent control structures following existing standards. The iterative approach of LCA methodology (ISO, 2006a) was used to record all important processes of the system and to supplement missing information. The LCA methodology has been developed from existing standards of the construction and product sector. Since the production of some construction materials takes place locally, the generic data, for Austria, was adapted. Wood inherent biogenic carbon and primary energy, used as raw material, are treated as materials inherent properties (CEN, 2014). The contribution of the various processes was reproduced by hotspot.Results and discussionHotspots of the different stages are related to the construction materials used. The emissions and primary energy inputs in the product stage are clearly dominated by concrete and steel. If these two materials are used sparingly, the focus is on machine application and transportation. Depending on the selected scenarios, the smallest share of emissions, in relation to the total result of product and construction stage emitted by transport, is 3% and the maximum share is 69%. The greatest environmental impacts in the construction stage are caused by excavation work and transportation on-site. With an average of 4% in the construction stage, the transport of workers to the construction site cannot be neglected as is done in the building sector.ConclusionsThe conclusion of this study is that existing LCA models can be adapted to protective structures. In contrast to conventional buildings, the construction process and transportation are much more important and cannot be neglected. Shifting the hotspots to these processes requires specific calculation rules for that particular field. There is still a need for research to find a suitable functional unit and to develop a methodology for the use and end of life stage of these structures.

Learning-by-doing: experience from 20 years of teaching LCA to future engineers

In support of the sustainable development of our societies, future engineers should have elementary knowledge in sustainability assessment and use of life cycle assessment. Publications on pedagogical experience with teaching life cycle assessment (LCA) in high-level education are however scarce. Here, we describe and discuss 20 years of experience in teaching LCA at MSc level in an engineering university with the ambition to share our insights and inspire teaching of LCA as part of a university curriculum. We detail the design of an LCA course taught at the Technical University of Denmark since 1997. The course structure relies on (i) a structured combination of theoretical teaching, practical assignments and hands-on practice on LCA case studies, and (ii) the conduct of real-life LCA case studies in collaboration with companies or other organisations. Through the semester-long duration of the course, students from different engineering backgrounds perform full-fledged LCA studies in groups, passing through two iterations—a screening LCA supporting a more targeted LCA. The course design, which relies on a learning-by-doing principle, is transparently described to inspire LCA teachers among the readers. Historical evolution and statistics about the course, including its 192 case studies run in collaboration with 105 companies and institutions, are analysed and serve as basis to discuss the benefits and challenges of its different components, such as the theory acquisition, the assignment work, the LCA software learning, the conduct of case studies, the merits of industrial collaborations and grading approaches. We demonstrate the win-win situation created by the setting of the course, in which the students are actively engaged and learn efficiently how to perform an LCA while the collaborating companies often get useful insights into their analysed case studies. The course can also be an eye opener for companies unfamiliar with LCA, who get introduced to life cycle thinking and the potential benefits of LCA. We have no hesitation in recommending industries and LCA teachers to engage into such collaborations even in the fundamental teaching of LCA techniques.

Small Scale In-Situ Bioremediation of Diesel Contaminated Soil – Screeing Life Cycle Assessment of Environmental Performance

Spillage of diesel oil and other petroleum products is a commonly creating need for site remediation of contaminated soils. In Sweden the most common remediation action is excavation of the contaminated soil and off site biological treatment by composting. However, a number of small sites spread out in rural areas end up low on priority lists, and will not be attended to within foreseeable future if ever. For such areas a low cost, easy to apply remediation techniques would be of interest. Enhanced bioremediation of diesel contaminants in soil by whey addition has been demonstrated in lab scale. Whey is a by-product from cheese production. A first pilot remediation trial on an actual site in Gäddede, County of Jämtland, was started the summer of 2010. Using this site as a case study a screening life cycle assessment model has been set up. The goal of the study was to investigate the environmental performance of the whey method, to benchmark the whey method toward the excavation and composting practice and to identify environmental hot spots in the whey treatment life cycle. The study aims at establishing if further work should be put into developing the method, or if the environmental performance is such that the whey method should be abandoned. It should be noted that even with a slightly worse environmental performance compared to other remediation alternatives whey treatment could still be of interest, since the small scale sites in rural areas we talk about here otherwise most often would not be attended to. Results from the screening life cycle assessment indicate a rather good environmental performance of the whey method, partly depending on impact category considered. For the whey method, impacts from farming activities in the milk production chain allocated to the whey give significant contributions. Transportation gives important impacts from both the whey method and the excavation and off site composting, thus logistics should always be considered and optimized. The whey onsite treatment could be an interesting alternative for bioremediation especially at sites that would not otherwise be treated, due to small size or remote location.

Life Cycle Assessment of a Virtual Reality Device

Virtual reality (VR) is one of the strongest trends for future communication systems. Considering the amounts of VR devices expected to be produced in the coming years, it is relevant to estimate their potential environmental impacts under certain conditions. For the first time, screening life cycle assessment (LCA) single score results are presented for a contemporary VR headset. The weighted results are dependent much on the source of the gold and the electric power used in production. Theoretically, using recycled gold for the VR subparts would be very beneficial seen from an environmental damage cost standpoint. Using low environmental impact electric power in the final assembly of the VR headset, in the final assembly of integrated circuits, and in the preceding wafer processing would also be worthwhile. Distribution of the final product is more pronounced than for other consumer electronics.

Development of Crop.LCA, an adaptable screening life cycle assessment tool for agricultural systems: A Canadian scenario assessment

There is an increasing demand for sustainable agricultural production as part of the transition towards a globally sustainable economy. To quantify impacts of agricultural systems on the environment, life cycle assessment (LCA) is ideal because of its holistic approach. Many tools have been developed to conduct LCAs in agriculture, but they are not publicly available, not open-source, and have a limited scope. Here, a new adaptable open-source tool (Crop.LCA) for carrying out LCA of cropping systems is presented and tested in an evaluation study with a scenario assessment of 4 cropping systems using an agroecosystem model (DNDC) to predict soil GHG emissions. The functional units used are hectares (ha) of land and gigajoules (GJ) of harvested energy output, and 4 impact categories were evaluated: cumulative energy demand (CED), 100-year global warming potential (GWP), eutrophication and acidification potential. DNDC was used to simulate 28 years of cropping system dynamics, and the results were used as input in Crop.LCA. Data were aggregated for each 4-year rotation and statistically analyzed. Introduction of legumes into the cropping system reduced CED by 6%, GWP by 23%, and acidification by 19% per ha. These results highlight the ability of Crop.LCA to capture cropping system characteristics in LCA, and the tool constitutes a step forward in increasing the accuracy of LCA of cropping systems as required for bio-economy system assessments. Furthermore, the tool is open-source, highly transparent and has the necessary flexibility to assess agricultural systems.

Early-stage sustainability assessment to assist with material selection: a case study for biobased printer panels

This paper aims to incorporate sustainability assessment into the material selection processes during early-stage product (re)design, when time and data availability for such assessments are usually limited. A material selection framework is presented and illustrated step-by-step with a case study aiming to identify biobased alternatives for petrochemical plastics used for (flame retardant) panels. After an initial screening step, the technical performance of selected materials is measured. A cradle-to-grave screening life cycle assessment compares the environmental performance of the candidate and reference materials on greenhouse gas emissions, non-renewable energy use and agricultural land use per kilogram. A simplified cost analysis is performed. The environmental and economic indicators are corrected for each candidate's technical performance by estimating expected weight changes in the final product based on material indices. In this case study, two biobased plastics are found to offer equal or improved environmental/economic performance compared to reference materials. Furthermore, the case study shows that additive production can significantly contribute to the plastics' environmental impacts, e.g. accounting for 5–40% of their cradle-to-grave greenhouse gas emissions. The case study demonstrated that the proposed materials selection framework is a useful tool for early-stage product design.

A Holistic Approach for Energy Flow Simulations in Early Design

The project focusses on the integration of energy saving technologies in the early design stage of ships, using advanced simulation models to be developed for the energy grid of the ship. The optimum combination of energy consumers incl. energy recovery systems is expected to significantly improve the vessels overall energy efficiency. The challenge will be to harmonize the modelling approach from technology providers in a way that component models can be used appropriately for energy modelling on ship level.The results of the simulation of the ship concepts as developed in the 11 application cases will be used for a screening life cycle assessment, using the “well to propeller” concept to properly address the use of alternative fuels. A LCPA (Life Cycle Performance Assessment)-Tool allows for the comparison of different technical solutions taking into account environmental and economic parameters. A suitable way of representing the external costs of air emissions will be integrated in order to be able to fully compare new technical solutions with existing state of the art technologies in ship designs for provision of political recommendations.

Life Cycle Assessment of Bioenergy and Bio-Based Products from Perennial Grasses Cultivated on Marginal Land in the Mediterranean Region

Agricultural systems in the Mediterranean region are increasingly getting under pressure due to both global warming and the aggravating competition for agricultural land. Perennial grasses have the potential to tackle both challenges: they are drought-resistant crops and considered not to compete for high-productivity agricultural land because they can be grown on marginal land. This paper presents the outcome of a screening life cycle assessment (LCA) conducted as part of an integrated sustainability assessment within the EU-funded project ‘Optimization of Perennial Grasses for Biomass Production’ (OPTIMA). The project aims at optimised production of Miscanthus (Miscanthus × giganteus), giant reed (Arundo donax L.), switchgrass (Panicum virgatum L.) and cardoon (Cynara cardunculus L.) on marginal land in the Mediterranean region. Different cultivation and use options were investigated by comparing the entire life cycles of bioenergy and bio-based products to equivalent conventional products. The LCA results show that the cultivation of perennial grasses on marginal land and their use for stationary heat and power generation can achieve substantial greenhouse gas emission and non-renewable energy savings, with Miscanthus allowing for savings ranging up to 13 t CO2 eq./(ha · year) and 230 GJ/(ha · year), respectively. Negative environmental impacts are less pronounced. Significant parameters include irrigation needs and moisture content at harvest, which determines energy demand for technical drying. We conclude that the cultivation of perennial grasses on marginal land in the Mediterranean region provides potentials for climate change mitigation together with comparatively low other environmental impacts, if several boundary conditions and recommendations are met.