LCA Studies Research Articles

Life Cycle Assessment for particleboards with recycled wood in an industrial context

Abstract The issue of depletion of natural resources carries side effects on human health, the ecosystem, and the planet itself. It is necessary to develop mitigation policies to reverse the actual climate trend. Both actions on small and large scales can make a relevant contribution to that problem. This paper aims to investigate two different approaches of the Life Cycle Assessment in an industrial context, in particular “ex-post” LCA is carried out for particleboards manufactured by a company using 100% recycled wood, while “ex-ante” LCA study is referred to a hypothetical particleboard manufactured equally to the previous product, but using 100% virgin wood, instead of recycled. The outcomes of the comparison of the two LCAs highlights that there are very relevant aspects to take into consideration when the environmental performance of a product is evaluated. In fact, CO2 emissions, which are one of the most concerning environmental impacts nowadays, and which is also orienting European policies, are not the only indicator that affect the impacts related to the human health, the natural environment, and the natural resources. The LCA tool is a complete tool capable to provide all-round environmental impacts of the studied object; in this research the results from the comparison of the two products’ LCA, pointed out how the “land use” increases in the case of the product made with only virgin wood, which is more than 20 times superior compared to the “land use” in the case of particleboard containing 100% recycled wood. The application of the two LCAs is structured on “cradle to gate” system boundary to highlight the impacts of the production process. For both ex-ante and ex-post application an interpretation is conducted to evidence their benefits, but with awareness of possible limits when they are utilized.

Scenario-based LCA for assessing the future environmental impacts of wind offshore energy: An exemplary analysis for a 9.5-MW wind turbine in Germany

BackgroundOffshore wind energy (OWE) will play a significant role in achieving climate neutrality. For example, several scenarios for Germany (e.g., Kopernikus base, Kopernikus 1.5 degree, Prognos CN65, and CN60) depict substantial OWE annual installed capacity additions, especially after 2030. This tendency promotes OWE technology development as deployment expands, allowing manufacturers to gain expertise and optimize wind turbine construction. The global trend towards ever-larger components (e.g., hub height and rotor diameter) is critical to achieving higher-rated capacities. These aspects and others, such as wind quality, influence not only OWE annual electricity production but also its environmental performance. In addition, future supply chains might reduce their environmental impacts and enhance OWE climate change mitigation. In this paper, a prospective life cycle assessment (pLCA) is developed and applied exemplarily for a 9.5-MW offshore wind turbine (OWT) on the North Sea coast of Germany for the years 2030 and 2050. Considering that the current OWTs under construction in Europe have an average capacity of 10 MW, Germany plans to instal OWTs of 9.5-MW. This exemplary OWT describes the potential advances for offshore wind turbines in 2030 and 2050, considering component scale-up and learning effects. Yet, the methodology is adaptable to various installed capacities and regions. This approach allows us to analyse not only the potential future characteristics of wind turbines, but also future developments in OWE supply chains. Therefore, relevant parameters related to OWT construction and operation (e.g., rotor diameter, hub height, distance to the shore, lifetime, etc.) as well as prospective life cycle inventory data for background systems that reflect potential future developments in the broader economy are considered. In this way, scenarios (e.g., optimistic, moderate, and pessimistic) for OWE elucidate the expected environmental impacts, such as climate change, marine eutrophication, and abiotic depletion potential, in 2030 and 2050.ResultsThe findings describe the variability of the environmental impacts of a 9.5-MW offshore wind turbine representing the technologies expected to be available in Germany in 2030 and 2050 and show that climate change impacts could vary between 7 and 18 g CO2-eq per kWh produced in 2030 and between 5 and 17 g CO2-eq per kWh in 2050. However, marine eutrophication could experience a significant increase (100% increase), depending on the consideration of hydrogen as a fuel in the electricity mix, as demonstrated in the climate-neutral scenarios adopted for Germany. Overall, construction efficiency improvements in 2050 might reduce the required materials, leading to a 6% decrease in abiotic depletion potential compared to 2030 values.ConclusionsThis paper highlights the need to consider temporal improvements in LCA studies, particularly when assessing the environmental impacts of offshore wind turbines. The complex nature and rapid growth of offshore wind technology require a comprehensive life cycle approach to deepen our understanding of its potential environmental impacts.

Consequential life cycle assessment of demolition waste management in Germany

ContextBulk mineral waste materials such as construction and demolition waste are Germany’s largest waste stream. Despite the availability of high-quality recycling pathways such as road base layers, waste concrete is predominantly recycled into lower-quality recycling pathways like earthworks or unbound road construction. This is due to low demand for recycled aggregates in road base layers and frost protection layers, especially in public procurement.PurposeThis study assesses the environmental consequences of increasing high-quality recycling of waste concrete in the near future to provide decision support for public procurement in Germany. The focus lies on climate change due to its importance for decision-makers. However, 17 other impact categories were assessed to avoid problem shifting.MethodsLife cycle assessment (LCA) is applied with background data from ecoinvent 3.9.1. Impact assessment was conducted at midpoint level using IPCC 2021 and ReCiPe Midpoint (H). Foreground data were taken from literature and expert interviews. In line with the goal of this LCA, a consequential modeling approach was followed to account for changes in the material flow system. Substitution creates a cascade effect previously omitted in consequential LCA studies, in which lower quality recycling materials replace higher quality recycling materials in their respective utilization pathways.Results and discussionIncreasing the high-quality recycling of waste concrete into road base layers causes a reduction in environmental impacts for all 18 impact categories, as it replaces natural aggregate and avoids backfilling of mixed mineral waste and excavated earth through substitution effects. Transport distances and ferrous metal recovery were identified as hot spots. Sensitivity analyses show that only transport is a significant issue.ConclusionIncreasing the high-quality recycling of waste concrete in Germany is recommended in terms of environmental impacts. Lower-quality recycling is environmentally feasible only in cases where the avoided transport distances for natural aggregates and backfilling are significantly lower than the additional transport distances for high-quality recycling.

Balancing Emerging Risks Considering the Life-Cycle Perspectives of Submerged Floating Tunnels for a Resilient Future Infrastructure

Infrastructure expansion considerably contributes to greenhouse gas emissions causing the critical global issue of climate change. In recent years, submerged floating tunnels (SFTs) have thus been developed as a sustainable and efficient solution for crossing large water bodies instead of resource-demanding superstructures (e.g., cable stayed bridges). This research delves into a comparative analysis of two SFT design alternatives: SFTs with pontoons and SFTs with tethers centered on environmental sustainability and long-term viability. By incorporating life-cycle assessments and quantitative risk analysis methodologies, our study aims to ascertain the optimal SFT design for real-world application. Our study embarks on detailed investigations into SFTs and then gathers data on material quantities and LCA studies, identifying potential hazards and comparing life cycle performance. Our new findings highlight the significant advantage of the SFT with a tethered design, which has a lower dependency on materials, particularly steels, resulting in lower CO2 emissions. Additionally, in terms of risk, the SFT with tethers has a lower risk profile in general, especially in situations, including environmental elements, like rising water levels, potential tsunamis, and storms. This design is a promising solution for sustainable and resilient infrastructure development, coinciding with global objectives to cut down carbon emissions and enrich potential benefits in the face of increasing climatic uncertainties. Not only does this study scrutinize the risk and environmental aspects of both SFT designs, but it also opens the path for future infrastructure projects that emphasize engineering robustness and environmental sustainability.

Comparison of ReCiPe 2016, ILCD 2011, CML-IA baseline and IMPACT 2002+ LCIA methods: a case study based on the electricity consumption mix in Europe

Abstract Purpose The international standards ISO 14040 and ISO 14044 do not specify a single method for the performance of life cycle impact assessment (LCIA). As a result, many different LCIA methods have been developed and the choice between them is not always obvious. Therefore, the main aim of this research is to systematically compare the most commonly used multi-impact LCIA methods worldwide to support practitioners in confronting the question of how the choice of LCIA method affects the LCA results. Methods Four LCIA methods: ReCiPe 2016, ILCD 2011, CML-IA baseline and IMPACT 2002+ at the midpoint level were applied to compare the environmental profiles of the electricity consumption mix in the EU-27, Norway, Switzerland and the United Kingdom, taking into account the electricity consumption mix in individual countries. The results of the impact categories were converted into common metrics using unit conversion factors to allow the comparison of the results in absolute values across LCIA methods. Results and discussion In the LCA study, four common LCIA methods were compared across 12 defined midpoint areas of impacts. Results were consistent for climate change and ozone depletion, with the exception of the ReCiPe 2016 method, and acidification and eutrophication, with the exception of the IMPACT 2002+ method. Significant disparities were noted for ozone formation/respiratory organics, particulate matter/respiratory inorganics ecotoxicity and water consumption. The rankings of environmental profiles remained largely consistent across LCIA methods, with only a few exceptions concerning the following midpoint areas of impacts: ozone formation/respiratory organics, ecotoxicity and resource scarcity (minerals). Contribution analysis highlighted the crucial role of only a few key substances in each area. Conclusions The methodological choices during LCIA have significant implications for the characterisation results in absolute values, but lead, in most cases, to comparable conclusions on the ranking of environmental profiles of the electricity consumption mix in the EU-27, Norway, Switzerland and the United Kingdom. This results from large methodological discrepancies between LCIA methods, concerning, among others, the geographical differentiation (either the European or global context), the scope of the impact categories grouped into the same midpoint area of impacts (for instance eutrophication) and the contribution of specific environmental flows to a given result of the impact category. Consequently, the findings of this research underpin the importance of careful selection of the LCIA method and impact categories, following the goal and scope definition and unique attributes of each method.

Review of published LCA Studies in a Developing Country: Case of Cameroon

Developed in the sixties, Life Cycle Assessment (LCA) gained attention around the world as environmental impact methods calculation. It’s application in Cameroon has received significant attention from both industry and research communities since the mid-2010s. This paper, aims to assess the current status of LCA published research conducted in Cameroon. The methodology was conducted using Scientific research websites and scientific journals databases with keywords such as “Life Cycle Assessment”, “LCA”, “Cameroon”, “Life cycle analysis”; then, Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) method was followed for the selection and analysis of the found papers. 16 LCA related studies with applications in Cameroon were found between 2010 and 2023. These studies focused on various sectors: construction (18.8%), bio - energy (18.8%), electricity (12.5%), waste management (6.3%), agriculture (18.8%), forest management (12.5%), Energy (6.3%) and other sectors (6.3%). The majority of these studies were conducted at the Yaounde I University, involving researchers from the National Advanced School of Engineering. Furthermore, none of the studies addressed economic/social life cycle assessment or life cycle costing. These aspects of LCA, which examine economic and social dimensions, are essential for gaining a comprehensive understanding of sustainability, particularly in developing countries like Cameroon.

Dynamic life cycle assessment of European electricity generation based on a retrospective approach

The composition of electricity varies significantly throughout the year. As a result, the environmental impact of the electricity mix is also highly variable. However, most LCA studies assume a static annual average electricity mix and neglect these fluctuations. Therefore, this study examines the time-varying environmental impacts of electricity generation in Germany, France, Italy, Spain, and Poland using a dynamic life cycle assessment. It shows that the impacts of environmental categories vary considerably depending on when the electricity is generated, resulting from the different energy generation patterns throughout the day and year. In particular, the integration of renewable energy sources such as photovoltaic systems and wind turbines leads to significant fluctuations of environmental impacts. To determine the magnitude of the variation, coefficients of variation are calculated for each environmental impact category for a representative year. High coefficients of variation of more than 20% can be observed for several environmental impact categories. In addition, both a production-based and a consumption-based approach were used for the dynamic life cycle assessment. Comparing these two approaches shows significant differences in impact category results, for example, for Italy, with an average of 15%. These differences highlight the importance of including cross-border electricity flows in assessing the environmental profile of electricity. Overall, the results of the study emphasize the need to implement dynamic electricity mix models in life cycle assessments, especially for systems with time-varying electricity consumption. The provided Excel spreadsheet files with hourly time profiles of environmental impacts for the countries studied facilitate the adoption of the developed models by other practitioners and provide a valuable tool for assessing environmental impacts.

Assessing environmental trade-offs in packaging systems for infant formula delivery: A cradle-to-gate plus end-of-life life cycle assessment

An LCA study was conducted comparing three packaging systems to deliver infant formula, including primary (plastic, composite, and steel containers), secondary (corrugated box), and tertiary (pallet) levels, all manufactured and distributed in North America. The project goal involved quantifying each system's environmental footprint (EF), evaluating the effect of end-of-life (EoL) modeling in LCA results, and interpreting trade-offs among environmental impact indicators.The functional unit was defined as a packaging system delivering 1000 g of infant formula from cradle-to-gate, plus EoL. The three packages, including EoL, were modeled using SimaPro 9.3.03, with TRACI 2.1 V1.06 Midpoint being the primary impact assessment method. The LCA was performed according to ISO 14040/14044 standards. EoL models included the cut-off method, the 50/50 allocation, and the circular footprint formula (CFF). The stochastic multi-attribute analysis (SMAA) method was implemented to evaluate the trade-offs among the midpoint indicators.The primary package significantly contributed to the three systems in all the evaluated categories. Adjusting the EoL models influences the overall results when comparing the packaging systems' impacts. Contributions in each category vary slightly, with minimal changeover from the highest or lowest package footprints in EoL models. The SMAA ranking preference for all EoL methods indicates that the plastic container is preferred, having the lowest EF with >50 % probability.Environmental impacts of the packages involved trade-off discussion. With the initial EoL methodology (cut-off method), Package 1 (plastic) shows the highest impact in 4 of the 10 impact categories, Package 2 (composite) in 2 of the 10 categories, and Package 3 (steel) in the remaining 4 categories. With the 50/50 allocation and CFF EoL methodologies, different conclusions were reached about the impacts of each package; however, SMAA results found that ranking of the packages within EoL methodologies did not change the conclusions that the plastic package is preferred.

To what extent do geopolitical conditions affect the environmental sustainability of the circular economy? A comparative LCA study of lactic acid production in Denmark and Iran

Transitioning to a circular economy is inevitable in well-developed and developing economies. Biowaste valorization into value-added products has shown a promising sustainable solution compared to its fossil-based counterparts. However, it has yet to be scientifically analyzed to what extent geopolitical conditions affect the environmental sustainability of the circular economy. To fill this gap, we conducted a consequential life cycle assessment of biorefining biowaste into lactic acid and bioenergy in Denmark and Iran as representative examples of developed and developing economies, respectively. Despite the notable environmental impacts associated with fossil-based energy consumption and infrastructural limitations, Iran could benefit more environmentally from the suggested biorefinery by 2030 than Denmark. This contrast arises from the fact that the existing dominant waste management solution in Iran consists of sanitized and unsanitized landfills, which appear likely to continue through 2030. Therefore, any alternative waste management scenario would help avoid the environmental impacts arising from landfills. In contrast, Denmark already has a well-established and sustainable waste management practice for biowaste, namely anaerobic digestion. Accordingly, the environmental impacts of the investigated scenarios in Denmark were, on average, 85 %, 855 %, 177 %, and 130 % higher than those in Iran regarding resource scarcity, ecosystem quality, human health, and climate change, respectively. In both countries, incineration, the culture medium, ion exchange, vacuum distillation, transportation, emissions from digestate applications on farmlands, and the inorganic waste landfilling process (only applied to IR scenarios) contributed most to the overall environmental impacts. Besides impacts arising from geopolitical conditions, our study revealed that abiotic augmentation and P. acidilactici bioaugmentation demonstrated superior environmental performance compared to other methods. The results also highlight the importance of international collaboration to implement circular economy approaches in developing countries and accelerating global environmental mitigation efforts. To comprehensively evaluate the environmental sustainability of circular bioeconomy, it is recommended to examine scenarios aligned with socio-economic pathways and various representative concentration pathways.

Carbon and water footprint of battery-grade lithium from brine and spodumene: A simulation-based LCA

Increasing demand for lithium driven by e-mobility spurs the expansion of lithium projects and exploration of lower-grade resources. This article combines process simulation (HSC Chemistry) and life cycle assessment tools to develop life cycle inventories considering declining ore grades scenarios for battery-grade Li2CO3 production from pivotal sources and regions (Salar de Atacama - brine and Greenbushes - spodumene). Depending on the ore grades, climate change results range from 5,0 to 25,0 kgCO2eq/kg Li2CO3 for brine and from 17,1 to 22,3 kgCO2eq/kg Li2CO3 for spodumene. Water consumption for brine varies from 0,2 to 7,7 m3/kg Li2CO3, depending on flow accounting, while for spodumene, it ranges from 0,2 to 0,5 m3/kg Li2CO3. The research shows that decreasing ore grade can lead to a fivefold increase in the carbon footprint for brine-based production and a 1.3-fold increase for spodumene. This underscores the importance of decarbonizing energy provision for lithium production to guarantee a sustainable battery supply chain. This research offers insights into using process simulation to enhance existing LCA studies in the raw materials industry and further develop inventory datasets, considering variations such as deposit ore grades.

Life cycle assessment of citrus tree nurseries in Uruguay: Are their environmental impacts relevant?

Perennial fruit production at the commercial scale, such as citrus fruits, begins with seedling production in a nursery. This stage lasts several months and involves different phases and the use of substrates and infrastructure. As the seedling does not produce fruit but does consume inputs, studying the environmental impacts associated with this stage becomes relevant, especially to understand its contribution to the total impact of the crop cycle. Despite the global relevance of fruit tree seedlings production, LCA studies in the literature focus on horticultural crop nurseries, and those on perennial tree nurseries do not consider both substrate and structures in the analysis, which is key for this type of crop since the main production system is soilless production in greenhouses. Thus, the main goal of this study is to quantify the environmental impacts related to the production of citrus fruit tree seedlings using LCA, analyse the main production system applied nowadays, and study its relevance with respect to the crop cycle. To this end, a certified Uruguayan citrus nursery was analysed, from which primary data was obtained. As well, methodological issues concerning water consumption and modelling emissions from input applications in soilless greenhouse systems are tackled. Results show that the main hotspots of the nursery stage are infrastructure production and peat transportation, which highlights the relevance of their inclusion when modelling the system. Extending the lifespan of the galvanised steel structures and decreasing substrate transport distances are shown to be effective measures to reduce environmental impacts. The contribution of the nursery stage to the citrus production cycle is negligible for almost all the impact categories assessed except cancer human toxicity, as it accounts for 0–3.6% of the impacts depending on the impact category. Great differences (from 10 to 400 times higher results on average) are observed when comparing the results with those from commercial databases, as they consider open-field nurseries where seedlings are grown in the soil. The need to develop harmonised methods to model water consumption and fertiliser and pesticide emissions for soilless crops in greenhouses arises. The present study presents a complete quantification of the environmental impacts of the main production system of citrus fruit tree seedlings and provides scientific and quantitative evidence of its contribution to the production cycle, helping decision-makers understand where efforts should be focused to achieve a more sustainable fruticulture.

Sustainable synthesis of levulinic acid using waste derived silica-alumina-hydroxyapatite supported nano ZrO2 photo-acidic catalyst under synergistic UV-FIR irradiations

A novel nano-photocatalyst has been prepared using hydroxyapatite (HAp) derived from waste fish scale and fly ash-derived aluminosilicate (SiO2-Al2O3) grafted with zirconium oxide (ZrO2) active sites by innovative photo-hydrothermal protocol. The physiochemical properties of the prepared photocatalyst have been characterized by different analyses like TGA, XRD, FTIR, XPS, UV–VIS–NIR, BET, NH3-TPD, HRTEM, and DLS. The optimal catalyst has a zirconium loading of 20 wt% and has a low bandgap energy of 2.15 eV as confirmed by UV–VIS–NIR spectroscopy. The optimal catalyst also depicted a high acidity of 1.52 mmol NH3/g and a specific surface area of 62.872 m²/g. Owing to the high acidity, specific surface area, and low band gap energy the photocatalyst has led to achieving an elevated yield of 76.6% levulinic acid (LA) from glucose in hybrid irradiation reactor (HIR) deploying UV and FIR radiations at appreciably low temperature and reaction time of 115 ℃ and 2 h respectively. Under the same reaction conditions, the conventionally heated reactor (CHR) gave a very low yield of 23.7%. Individual radiation effects on LA yield evinced the synergistic advantageous effect of the hybrid irradiation technique. The catalyst reusability and regenerative study confirmed the high stability of the prepared catalyst. Also, a comparative LCA study has been conducted between HIR and CHR systems which revealed that HIR was more environmentally sustainable than CHR. HIR -based process demonstrated a reduction in 59% global warming potential, 70.66% forest resource scarcity, and 65% lower terrestrial ecotoxicity while being 120% more energy efficient than CHR-based reaction making HIR more environmentally sustainable as well as economically feasible.

Life cycle assessment of baby leaf spinach: Reduction of waste through interventions in growing treatments and packaging

Salad vegetables are an important dietary nutrient source, but are prone to spoilage, and actions to reduce waste are being explored and assessed. The Leaf No Waste project aims to reduce food and packaging waste in Ireland, by extending the shelf life of leafy vegetables through growing treatments and packaging choices. This LCA study assessed environmental impacts of a silicon foliar treatment and packaging choices - Oriented Polypropylene (OPP) and Polylactide Acid (PLA) for baby leaf spinach, focussing on climate change, terrestrial acidification, freshwater eutrophication, fossil resource scarcity, and water use. The production of spinach, storage, packaging, retail, and waste management of the spinach supply chain are included in the system boundary, for 1 kg packed baby leaf spinach. The results illustrate that the silicon foliar treatment reduces waste, and LCA of the silicon foliar treatment for baby leaf spinach in OPP packaging under 3-day shelf life demonstrates limited effects on climate change (323 vs 321 g CO2-eq/kg), freshwater eutrophication (21.4 vs 20.9 mg P-eq/kg), and water use (10.2 vs 10 L/kg), increased impact on fossil resource scarcity (98.6 vs 91.4 g oil-eq/kg) and lowers impact on terrestrial acidification (3573 vs 3997 mg SO2-eq/kg). PLA packaging has a greater impact than OPP packaging in all impact categories, except fossil resource scarcity. The 7-day shelf life causes more impacts than the 3-day shelf life, except for the scenario with PLA packaging in the impact category of fossil resource scarcity. The results of this study identify environmental hotspots of an Irish spinach supply chain and are preliminary evidence to support actions to reduce waste in fresh leaf spinach supply chains from packaging to retail.

Is normalization in Life Cycle Assessment sustainable? Alternative approach based on natural constraints

Life cycle assessment, a widely used methodology of environmental impact assessment, employs the step called normalization to allow comparison and contextualization of the multiple environmental impacts driven by human activities. However, the currently used normalization references based on total human impacts do not reflect any sustainability limits. This leads to a paradox where the more humanity causes an impact, the less important it appears in the results. We propose that normalization references be based on natural constraints, values that delimit the level of impact which can be expected to cause no significant harm. Such approach can be applied to most characterization methodologies, as we demonstrate on the case of Environmental Footprint methodology with 16 impact categories. In this work we quantify such normalization references, we compare them to the currently used values and we statistically test the difference on the case of 60 processes from common LCA databases. The results show that the proposed normalization method significantly changes the relative ranking of most of the impact categories. According to our findings, the proposed method may alter the ranking of assessed scenarios and change the conclusions and recommendations of LCA studies. This shift in the rationale for normalization can provide a different perspective on results interpretation and thus offer more robust policy guidance.

Can LCA be FAIR? Assessing the status quo and opportunities for FAIR data sharing

AimThe purpose of this study is to assess the status quo of data sharing in LCA in relation to the FAIR (findability, accessibility, interoperability, and reuse) data principles.MethodsThis study investigates how is LCA data from publicly funded research currently shared. Firstly, the focus is on life cycle inventory data shared in journal articles. Given that FAIR data sharing is not only the responsibility of the LCA practitioner, this study further investigates guidelines (e.g., data sharing standards and data management plans) and infrastructure (repositories, data formats, and nomenclature) to identify the tools and services available to LCA community which are essential to enable FAIR data sharing.ResultsThe study identifies that although there is growing awareness to improve data sharing practices, implementation of FAIR guidelines for data sharing is seldom seen in practice. LCA studies that adhere to FAIR principles are primarily due to use of generic data repositories which provide tools to support data sharing. However, there is no guidance on how LCA specific data should be shared to ensure its findability, accessibility, interoperability, and reusability. This study suggests a workflow to enable FAIRification of LCA data. In addition, the study recommends further efforts within the LCA community on skill and technology development, strategic funding, and recognition of the best practices in relation to data sharing.ConclusionIn conclusion, this study highlights the necessity of data sharing incentives, guidelines, and platforms/repositories specific for the LCA community.

Re: “What Should Students Learn Through LCA Studies?”: A Question from 10 Years Ago

Re: “What Should Students Learn Through LCA Studies?”: A Question from 10 Years Ago

Waste Plastics Chemical Recycling in the Context of Refining and Petrochemical Industries

Rising demand for plastic materials results in increasing volumes of plastic waste generated globally. This poses a question of waste collection and handling of the growing waste volumes. With quality limitations of reuse and mechanical recycling, especially end-of-life mixed plastic waste is mostly landfilled, incinerated or lost to environment. Thermochemical recycling, especially pyrolysis, has been historically explored as an attractive alternative waste processing method with a potential to valorise the plastic waste into energy, fuels and more recently also chemicals and virgin polymers. Thermochemical plastic waste processing and treatment of the intermediates towards the final products have been found to be studied mostly in isolation. Therefore, this study provides a combined view. Updated state of pilot and demonstration projects is reviewed. Typical characteristics of plastic waste pyrolysis products are introduced and the areas of potential impacts on existing plants are highlighted. In order to address the circularity and economic aspect, a summary of recent relevant LCA and business studies is provided, showing common sensitivity factors and main assumptions used therein. Overall, this review summarizes the background behind the recycling of waste plastics and presents it in context of challenges and opportunities of integration with existing refining and petrochemical infrastructure.

Towards sustainable production of sesame products: Comparison of traditional and modern production systems via a life cycle assessment approach

Burgeoning ecological crises of food production sector has made the environmental impact evaluation of various food products a sustainability imperative. Specifically, in pursuit of identifying a sustainable production model of high-demand food items, implementing a comparative life cycle assessment of various production approaches is of paramount importance. The energy consumption and environmental impacts of manufacturing two popular sesame products, Tahini (milled sesame paste) and Halva (sweetened sesame paste) in Iran was realized by using life cycle assessment methodology. In this regard, two production systems of traditional and modern, based on sesame cultivation and processing seeds were modeled. Moreover, production of milling stone, as the main instrument in Tahini and Halva production, was evaluated within the boundary of each product system. The highest energy used pattern and carbon footprint were attributed to the traditionally produced Tahini with 89.3 MJ/kg and 12.4 kg CO2eq/kg respectively; while, the lowest results were associated with modern-based Halva production with 47.8 MJ/kg and 5.4 kg CO2eq/kg. Compared to the traditional method, modern production of tahini was found to increase acidification potential and ozone layer depletion potential the most, with 73.1 g SO2eq and 0.735 mg R11eq respectively. Production of milling stone was the predominant hotspot for all products in traditional and modern systems, with average of 56% and 45% contribution to the total energy used, and 75% and 71% contribution to the carbon footprint of products in the former and latter systems respectively. Moreover, implementation of agrivoltaics system and circular economy-based milling stone as the alternative scenarios were evaluated from LCA perspective, which demonstrated that adoption of alternative milling stone could reduce the impact results significantly. It is believed that the novel evaluation framework of this study could serve as an example for future LCA studies to expand the common routine of evaluation and include production of instrument within the product's system boundary.

Life cycle assessment of recycling high impact polystyrene and acrylonitrile butadiene styrene plastic from waste refrigerators

Recycling waste refrigerator plastics can effectively reduce waste accumulation and carbon emissions. This study firstly applied the combination of electrostatic separation and magnetic separation in the waste refrigerators production line to recycle High-impact polystyrene (PS) and acrylonitrile butadiene styrene (ABS) plastics. A cradle-to-gate LCA study of recycling plastic from waste refrigerators was conducted. A carbon emission accounting system for the life cycle of waste plastic recycling was established, each emission unit was identified, the environment impact was analyzed. The results show that disposing waste polyurethane (PU) has the great impacts on eco-toxicity, and the use of high-power machines and Kraft paper packaging has great impacts on resources. The greenhouse gas emission generated during the life cycle is 8.53 kg·CO2eq/kWh. The greenhouse gas emission by recycling1kg ABS and HIPS was 2.59 kg·CO2eq/kWh and 1.84 kg·CO2eq/kWh, which is 84.35% and 61.61% less than producing virgin ABS and HIPS plastic from petrochemical industry. From 2016 to 2030, recycling waste refrigerators can reduce the total of 6452.06 kt waste plastics and greenhouse gas emissions by 370,350 tons. This study provides a scientific basis for exploring waste plastic recycling strategies and promoting green transition of the plastic industry.

Life cycle assessment in the recycling of waste printed circuit boards and lithium-ion batteries: systematic literature review

This research aims to analyze life cycle assessment (LCA) studies covering recycling of printed circuit boards (PCB) and lithium-ion batteries from waste electrical and electronic equipment. The method of systematic literature review was used in addition to structured content analysis, to extract relevant data from 22 peer-reviewed scientific articles. The results show that the research topic is expanding, indicating an increased trend in research in the future. Most lca studies are focused on contexts of developed countries, indicating a research need in developing countries. The results of the content analysis point that most studies carried out LCA of PCB recycling, indicating that investigations in lithium-ion battery recycling processes are scarce in the literature. The treatment methods with the highest number of lca studies are pyrometallurgical and hydrometallurgical. New techniques such as bioleaching, physical recycling, relitiation, and functional recycling have been found, however, it is needed to perform more studies on the environmental impacts of these recycling methods.