1. Environmental impact assessment of organic rankine cycle using waste heat from the aluminium industryMonika Dokl, Gaja Strajnar, Annamaria Vujanović, Jan Puhar, Zdravko Kravanja, Lidija Čuček, 2025, izvirni znanstveni članek Opis: Waste heat recovery technologies play an important role in enhancing energy efficiency and supporting sustainable energy production. This study investigates the utilization of waste heat from aluminium production through an Organic Rankine Cycle (ORC) system to generate electricity and heat simultaneously. Based on operational data from an aluminium plant, the system is firstly optimized from both the thermodynamic and economic perspectives. To maximize performance and to identify optimal configurations, a mathematical model is developed and solved using GAMS, capturing the complex interdependencies between the operational, economic and thermodynamic parameters. The environmental impact of the optimized scenarios is subsequently evaluated using a Life Cycle Assessment (LCA), considering a broad range of impact categories. The results indicate a maximum power output of 830.9 kW and a maximum net present value (NPV) of 51.71 M€, confirming the system’s technical and economic viability. The environmental assessment demonstrates the potential of ORC systems as sustainable energy solutions, with significant environmental unburdening under optimized operating conditions (up to -606.0 kg CO2 eq./h). A sensitivity analysis indicates that the greatest environmental benefits occur under the optimal thermodynamic scenario, achieved through the utilization of higher-energy flue gas streams (up to -515.0 kg CO2 eq./h), and under the optimal economic scenario by balancing the electricity and heat prices optimally for simultaneous heat and power production (up to -696.7 kg CO2 eq./h). These findings highlight the importance of the thermal input quality and availability in maximizing ORC performance. With the ability to prioritize electricity, heat, or both, the optimized ORC systems support flexible energy solutions tailored to specific applications and environmental conditions, offering a promising pathway for unburdening the environment through the efficient utilization of industrial waste heat.
Ključne besede: waste heat recovery, aluminium production, organic rankine cycle, environmental impact, life cycle assessment, sustainable energy solutions
Objavljeno v DKUM: 13.06.2025; Ogledov: 0; Prenosov: 3
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2. The environmental and biodiversity impacts of a new cableway system : a comprehensive life cycle assessmentAnnamaria Vujanović, Andrea Mio, Rok Pučnik, Nicola Blasuttigh, Damjan Krajnc, Maurizio Fermeglia, 2024, izvirni znanstveni članek Opis: Cars are still used as the primary mode of transportation for daily commuting, with their emissions significantly affecting urban air quality, contributing to overall greenhouse gas emissions. Efforts to reduce car dependency have led to exploration of alternative transportation options such as cableway systems in urban areas. However, limited information exists regarding the environmental impacts and biodiversity implications of such systems. This study conducted a comparative life cycle assessment between a proposed cableway system for the city of Trieste, Italy and its current car transportation mode. The analysis considered both daily operational profiles and passenger occupancy rates of the cableway system. Drawing from similar cableway systems worldwide, it was calculated that the proposed Trieste cableway would accommodate 2007 daily passengers, on average. Results from the environmental assessment revealed that the cableway's operational phase had by far the greatest impact on all environmental categories, followed by its construction and by land clearance. Additionally, the use phase was found to be the major cause for most biodiversity loss, particularly towards terrestrial ecosystems. Comparisons of life cycle GHG emissions between the cableway and car transportation indicated that the cableway system would be a preferable option if the daily average passengers would reach at least 3,908, which is almost double than the expected ones. Furthermore, the cableway system exhibited larger environmental impacts across most categories compared to current car transportation. Thus, this study challenges the perception that the cableway system is a more sustainable option compared to conventional modes of transport, as additional factors need to be considered for a broader overview of the environmental performances.
Ključne besede: life cycle assessment, cableway, ropeway, urban, biodiversity, carbon footprint
Objavljeno v DKUM: 23.04.2025; Ogledov: 0; Prenosov: 2
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3. When technology meets sustainability: microplastic removal from industrial wastewater, including impact analysis and life cycle assessmentJan Puhar, Michael Toni Sturm, Erika Myers, Dennis Schober, Anika Korzin, Annamaria Vujanović, Katrin Schuhen, 2025, izvirni znanstveni članek Opis: Microplastics (MPs) that are ubiquitous in aquatic environments and industrial wastewater streams have been identified as key hotspots of MP contamination. It is significantly more effective to remove MPs at these points before they enter municipal wastewater streams. This study is an environmental assessment of a novel pilot plant for the removal of MPs and the chemical oxygen demand (COD) from wastewater with a high MP contamination from a plastics manufacturer in Germany. MP removal is based on physical–chemical agglomeration–fixation by organosilanes. Formed agglomerates are separated using a belt filter. The COD is removed by an adsorption process. The resulting MP removal was 98.0 ± 1.1% by mass and 99.9987 ± 0.0007% by particle count, while the COD was reduced by 96 ± 2.7%. The system’s sustainability is evaluated using the Life Cycle Assessment methodology, evaluating system construction, operation, and end-of-life considerations. The current pilot plant is also compared to an optimized circular and sustainable upgrade, where drivers of environmental burdens are eliminated and collected MPs are reused. Significant reductions in environmental impact categories are achieved and the global warming potential is reduced by 96%. This study provides a sustainability assessment of a novel technology and circular solution to remove MPs from highly polluted industrial wastewater.
Ključne besede: microplastics, life cycle assessment, impact analysis, removal technology, sustainable process design, carbon footprint, water quality, circular economy
Objavljeno v DKUM: 14.03.2025; Ogledov: 0; Prenosov: 4
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4. Global projections of plastic use, end-of-life fate and potential changes in consumption, reduction, recycling and replacement with bioplastics to 2050Monika Dokl, Anja Copot, Damjan Krajnc, Yee Van Fan, Annamaria Vujanović, Kathleen B. Aviso, Raymond R. Tan, Zdravko Kravanja, Lidija Čuček, 2024, izvirni znanstveni članek Opis: Excessive production, indiscriminate consumption, and improper disposal of plastics have led to plastic pollution and its hazardous environmental effects. Various approaches to tackle the challenges of reducing the plastic footprint have been developed and applied, such as the production of alternative materials (design for recycling), the production and use of biodegradable plastic and plastics from power-to-X, and the development of recycling approaches. This study proposes an optimisation strategy based on regression to evaluate and predict plastic use and end-of-life fate in the future based on historical trends. The mathematical model is formulated and correlations based on functions of time are developed and optimised by minimising the sum of squared residuals. The plastic quantities up to the year 2050 are projected based on historical trends analysis, and for improved sustainability, projections are additionally based on intervention analyses. The results show that the global use of plastics is expected to increase from 464 Mt in 2020 up to 884 Mt in 2050, with up to 4725 Mt of plastics accumulated in stock in 2050 (from the year 2000). Compared to other available forecasts, a slightly lower level of plastic use and stock are obtained. The intervention analysis estimates a range of global plastics' consumption between 594 Mt and 1018 Mt in 2050 by taking into account its different increment rates (between −1 % and 2.65 %). In the packaging sector, the implementation of reduction targets (15 % reduction in 2040 compared to 2018) could lead to a 27.3 % decrease in plastic use in 2050 as compared to 2018, while achieving recycling targets (55 % in 2030) would recycle >75 % of plastic packaging in 2050. The partial substitution of fossil-based plastics with bioplastics (polyethylene) will require significant land area, between 0.2 × 106 km2 for obtaining switchgrass and up to around 1.0 × 106 km2 for obtaining forest residue (annual yields of 58.15 t/ha and 3.5 t/ha) in 2050. The intervention analysis shows that proactive policies can mitigate sustainability challenges, however achieving broader sustainability goals also requires reduction of footprints related to energy production and virgin plastic production, the production of bio-based plastics, and the full implementation of recycling initiatives.
Ključne besede: plastic use, plastic waste, end-of-life fate, forecasting, hostorical trends, regression analysis, least square method, intervention analysis
Objavljeno v DKUM: 31.01.2025; Ogledov: 0; Prenosov: 5
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5. Energy demand distribution and environmental impact assessment of chitosan production from shrimp shellsFilipa A. Vicente, Robert Hren, Uroš Novak, Lidija Čuček, Blaž Likozar, Annamaria Vujanović, 2024, izvirni znanstveni članek Opis: Step towards resilience and sustainability through exploring renewable biomass and waste streams to produce higher-added value products and energy is among key aspects for closing the loops, saving resources, and reducing the resource and emission footprints. In that respective, crustacean shells waste can offer rich spectre of valuable compounds such as proteins, chitin, carotenoids. This waste is produced in large quantities worldwide, thus allowing for commercial valorisation. An overview of technologies is undertaken for more sustainable and environmentally friendly chitosan production via chitin isolation and conversion and compared to the conventional processes. Furthermore, an assessment of the environmental burden and energy demand distribution for conventional and more sustainable alternative processes was performed, based on lab-scale experimental data. Three different chitin extraction routes and three distinct chitosan conversion processes were considered and compared for their greenhouse gas footprint, abiotic depletion, acidification, eutrophication and other potentials. Finally, the energy demand distribution was analysed considering electricity production patterns from three European countries, Slovenia, Portugal and Norway. The results showed that alternatives 3-A and 3-B (conventional eco-solvents - conventional deacetylation with 40 % and 50 % NaOH) generate the lowest environmental burden (184 g CO2 eq./g chitosan). Electricity was the main hotspot of the processes, used either for extraction, plasma treatment or deacetylation. The sensitivity analysis proved that the Norwegian electricity mix has the lowest environmental impact (4.2 g CO2 eq./g chitosan). This study highlights the impact of blue biorefineries by transforming marine waste to valuable biopolymers such as chitin and chitosan.
Ključne besede: shrimp shells waste, blue biorefinery, value-added products, chitosan, sustainable production, comparative environmental assessment
Objavljeno v DKUM: 08.01.2025; Ogledov: 1; Prenosov: 7
Celotno besedilo (2,16 MB)
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6. Ekonomska analiza življenjskega cikla proizvoda iz recikliranega najlona : diplomsko delo visokošolskega strokovnega študijskega programa I. stopnjeAjda Podlesnik, 2024, diplomsko delo Opis: Diplomska naloga obravnava ekonomsko analizo življenjskega cikla proizvoda iz recikliranega najlona, pridobljenega iz odpadnih ribiških mrež. Glavni poudarek naloge je na preučevanju celotnega procesa recikliranja ter analizi ekonomske učinkovitosti tega procesa. S procesom smo zajeli vse korake, od zbiranja odpadnih ribiških mrež, preko mehanske in termomehanske obdelave, do končne izdelave proizvoda.
Čeprav so odpadne ribiške mreže odpadni material, njihova predelava predstavlja izziv, saj stroški predelave in proizvodnje sekundarnih surovin niso zanemarljivi. V procesu recikliranja je največji strošek povezan z ročnim razvrščanjem in ločevanjem materialov. Kljub temu ima proces recikliranja odpadnih ribiških mrež velik potencial, saj prispeva k zmanjšanju onesnaževanja oceanov in zmanjšani uporabi surovin, kar je pomembno z vidika trajnostnega razvoja. Z izboljšanjem tehnologij in večjo avtomatizacijo procesa bi lahko stroške recikliranja občutno zmanjšali, kar bi posledično izboljšalo tudi ekonomsko učinkovitost raziskovanega procesa recikliranja.
Ključne besede: recikliranje, recikliran najlon, odpadne ribiške mreže, ekonomska analiza, življenski cikel
Objavljeno v DKUM: 16.09.2024; Ogledov: 8; Prenosov: 43
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7. Decomposition and fragmentation of conventional and biobased plastic wastes in simulated and real aquatic systemsOlivija Plohl, Lidija Fras Zemljič, Alen Erjavec, Noemi Sep, Maja Čolnik, Yee Van Fan, Mojca Škerget, Annamaria Vujanović, Lidija Čuček, Julija Volmajer Valh, 2024, izvirni znanstveni članek Opis: Plastics play a crucial role in our daily lives. The challenge, however, is that they become waste and contribute to a global environmental problem, increasing concerns about pollution and the urgent need to protect the environment. The accumulation and fragmentation of plastic waste, especially micro- and nanoplastics in aquatic systems, poses a significant threat to ecosystems and human health. In this study, the decomposition and fragmentation processes of conventional and biobased plastic waste in simulated water bodies (waters with different pH values) and in real water systems (tap water and seawater) are investigated over a period of one and six months. Three types of plastic were examined: thermoplastic polyethylene terephthalate and thermoset melamine etherified resin in the form of nonwovens and biobased polylactic acid (PLA) in the form of foils. Such a comprehensive study involving these three types of plastics and the methodology for tracking degradation in water bodies has not been conducted before, which underlines the novelty of the present work. After aging of the plastics, both the solid fraction and the leachate in the liquid phase were carefully examined. The parameters studied include mass loss, structural changes and alterations in functional groups observed in the aged plastics. Post-exposure assessment of the fragmented pieces includes quantification of the microplastic, microscopic observations and confirmation of composition by in situ Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy. The leachate analysis includes pH, conductivity, turbidity, total carbon and microplastic size distribution. The results highlight the importance of plastic waste morphology and the minor degradation of biobased PLA and show that microfibers contribute to increased fragmentation in all aquatic systems and leave a significant ecological footprint. This study underlines the crucial importance of post-consumer plastic waste management and provides valuable insights into strategies for environmental protection. It also addresses the pressing issue of plastic pollution and provides evidence-based measures to mitigate its environmental impact.
Ključne besede: polylactic acid, polyethylene terephthalate fabric, melamine etherifed resin fabric, aquatic environment, fragmentation, waste disposal
Objavljeno v DKUM: 09.09.2024; Ogledov: 73; Prenosov: 26
Celotno besedilo (3,73 MB)
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8. A waste separation system based on sensor technology and deep learning: a simple approach applied to a case study of plastic packaging wasteRok Pučnik, Monika Dokl, Yee Van Fan, Annamaria Vujanović, Zorka Novak-Pintarič, Kathleen B. Aviso, Raymond R. Tan, Bojan Pahor, Zdravko Kravanja, Lidija Čuček, 2024, izvirni znanstveni članek Ključne besede: waste management, smart waste bin system, central post-sorting, sensor technology, deep learning, convolutional neural networks
Objavljeno v DKUM: 23.08.2024; Ogledov: 51; Prenosov: 11
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9. Hydrogen production, storage and transport for renewable energy and chemicals : An environmental footprint assessmentRobert Hren, Annamaria Vujanović, Yee Van Fan, Damjan Krajnc, Jiri Klemeš, Lidija Čuček, 2023, izvirni znanstveni članek Ključne besede: hydrogen producing technologies, hydrogen storage, hydrogen transport, life cycle assessment, different electricity sources, energy and environmental footprints, eco-benefit and eco-cost, comparative impact assessment
Objavljeno v DKUM: 10.05.2024; Ogledov: 240; Prenosov: 85
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10. Life Cycle Assessment of Pilot-Scale Bio-Refining of Invasive Japanese Knotweed Alien Plant towards Bio-Based Bioactive CompoundsRobert Hren, Katerina Naumoska, Urška Jug, Lidija Čuček, Blaž Likozar, Uroš Novak, Annamaria Vujanović, 2023, izvirni znanstveni članek Opis: Japanese knotweed is an invasive alien plant species with characteristic rapid expansion in Europe and North America and resistance to extermination. It displaces autochthonous biodiversity and causes major damage to infrastructure, thus causing global ecological and economic damage. The Japanese knotweed plant is usually eradicated using various chemical, biological, or mechanical techniques, which at a large scale include heavy equipment, usually followed by incineration. Therefore, excavation is preferred to eradication techniques, and as a biomass waste recovery method due to the extraction of high-value biocompounds. This is supported by the fact that the Japanese knotweed possesses various bioactive compounds with beneficial effects on human health. Its rhizome bark extract produces strong and stable antioxidant activity over time, as well as apoptotic, antibacterial, and other beneficial activities. In this work, an environmental impact assessment, including greenhouse gas footprint, acidification, eutrophication, and ecotoxicity for extraction route of the Japanese knotweed rhizome bark, is performed. A comparative case study between the lab-based and proposed pilot-scale production of active added-value extract was evaluated. The results show the pilot-scale production exhibits lower environmental burdens, mainly due to greater electricity requirements for the lab-scale alternative.
Ključne besede: Japanese knotweed rhizome bark extract, invasive alien plant species, bioactive compounds, lab-scale, pilot-scale, life cycle assessment (LCA), environmental burden assessment
Objavljeno v DKUM: 19.03.2024; Ogledov: 236; Prenosov: 20
Celotno besedilo (1,31 MB)
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