1. Environmental priorities in the circular economy : examples from iron-based technologiesAndreea Oarga-Mulec, Uroš Luin, Keith R. Skene, Matjaž Valant, 2024, published scientific conference contribution Abstract: The circular economy (CE) framework is crucial for promoting resource efficiency and minimizing waste, but it cannot achieve its sustainability goals alone. To achieve a truly sustainable future, broader social, environmental and economic aspects need to be taken into account. Rather than separating biological and technological cycles, as the CE principles are depicted in the Ellen MacArthur Foundation’s butterfly diagram (EMF, 2017), we propose an integrated approach that prioritises environmental aspects and includes a conceptual framework, socio-economic changes and implementation processes. It is crucial to re-evaluate the environmental aspects and strengthen their importance within the CE framework. Within this concept we present the case of iron, the most widely used metal, widely available compared to others and has been an essential part of societal development for more than 5,000 years. With its abundance, safety and electrochemical properties, iron is an ideal material for low-carbon energy technologies. We discuss how advanced iron-based technologies have a high potential to be successfully integrated into the CE, we evaluate different electrochemical energy storage systems and present advances in thermochemical Fe-Cl cycles for hydrogen production. An innovative thermal system for hydrogen production based on the thermochemical Fe-Cl cycle was evaluated in a life cycle assessment (LCA) study and shows the importance of choosing sustainable energy sources to minimise environmental impact. Sustainable production methods for iron are also analysed to demonstrate their potential to reduce the carbon footprint of the iron and steel industry. Finally, efforts should focus on minimising environmental impact and optimising resource recovery. Keywords: circular economy, resource efficiency, sustainability, iron, hydrogen Published in RUNG: 25.11.2024; Views: 215; Downloads: 0 This document has many files! More... |
2. Analysis of circular economy implementation in local communityHenrik Gjerkeš, Marjana Šijanec-Zavrl, 2023, published scientific conference contribution Abstract: An analysis of the implementation of the comprehensive circular economy concept in Slovenia is presented. The concept used takes advantage of the endogenous potential of the area in which it is implemented and is aimed at the development of the forest-wood chain in the municipality of Kočevje. The results of the current 7-year implementation of the circular economy have shown a balanced fulfilment of all three dimensions of sustainable development: sustainable management of forests and products (FSC, PEFC), financial viability of operations and increased contributions to all public treasuries - even in time of crisis, more than 50 new green workplaces, increased interest of private investors, promotion of tourism, and last but not least - positive multiplicative effects on the quality of life of the citizens of Kočevje. Cyclicality is ensured in this way and the circular economy successfully fulfils its purpose. Keywords: circular economy, sustainable development, implementation Published in RUNG: 27.11.2023; Views: 1327; Downloads: 7 Link to file This document has many files! More... |
3. THERMOCHEMICAL CONVERSION OF MARINE LITTER INTO FUELS AND CHEMICALSGian Claudio Paolo Faussone, 2023, doctoral dissertation Abstract: Plastic waste is steadily polluting oceans and environments. Even when collected, it is still predominantly dumped or incinerated for energy recovery at the cost of CO2. However, no simple solution exists to deal with marine litter (ML). Overcoming limitations in collection, and in the environmentally, technically and economically acceptable use of the collected material, is of paramount importance. Chemical recycling can contribute to the transition towards a circular economy but the high variety and contamination of real waste remains the biggest challenge. In my research more than 100 kg of actual benthic ML from the North Adriatic Sea, including polyolefins packaging and polyamides fishing nets, were successfully processed “as-is” without pretreatment and converted into standardized marine gas oil (MGO) compliant with the ISO8217 via the pyrolysis and the distillation process; with 8 potential harmful emissions linked to the pyrolysis process monitored and curbed to safe levels. Approximately 45 wt% yield of raw pyrolysis oil (RPO) was obtained of which 50% (v/v) being MGO. RPO and its distillates were chemically characterized via GC-MS. For all samples, more than 30% of the detected compounds were identified. 2,4-dimethyl-1-heptene, a marker of PP pyrolysis, is the most represented peak in the chemical signature of all the marine litter samples, and it differentiates commercial and pyrolysis marine gasoil. Besides, I studied the detailed composition and the steam cracking performance of distilled pyrolysis oil fractions in the naphtha-range of ML and mixed municipal plastic waste (MPW) considered unsuitable for mechanical recycling. Advanced analytical techniques including comprehensive two-dimensional gas chromatography (GC × GC) coupled with various detectors and inductively coupled plasma – mass spectrometry (ICP-MS) was applied to characterize the feedstocks and to understand how their properties affect the steam cracking performance. Both waste-derived naphtha fractions were rich in olefins and aromatics (~70% in MPW naphtha and ~51% in ML naphtha) next to traces of nitrogen, oxygen, chlorine and metals. ICP-MS analyses showed that sodium, potassium, silicon and iron were the most crucial metals that should be removed in further upgrading steps. Steam cracking of the waste-derived naphtha fractions resulted in lower light olefin yields compared to fossil naphtha used as benchmark, due to secondary reactions of aromatics and olefins. Coke formation of ML naphtha was slightly increased compared to fossil naphtha (~50%), while that of MPW naphtha was more than ~180% higher. It was concluded that mild upgrading of the waste-derived naphtha fractions or dilution with fossil feedstocks is sufficient to provide feedstocks suitable for industrial steam cracking. Waste plastics oil (WPO) obtained from a relatively large-scale batch rotary kiln pyrolysis reactor was collected and stored for 60 months in dark at 10 °C, periodically thoroughly characterized and finally tested as the drop-in fuel in internal combustion engine. It was evaluated by investigation of combustion process and emission formation phenomena under a wide range of operating parameters. The results were compared with those obtained with diesel fuel at the same injection and gas path parameters to provide a comprehensive basis for further development of control strategies. Finally, the solid residue from the pyrolysis process was evaluated for material recovery or safe disposal, thus closing the mass balance of the whole process. Due to the great contamination of the original feedstock, stabilization of solid residue is required to attain not hazardous waste criteria, but once stabilized with Portland concrete, it could even be employed as construction material, therefore transforming a problem into an opportunity. Keywords: marine litter, marine fuel, pyrolysis, circular economy, environmental impact, chemical recycling, steam-cracking, pyrolysis char Published in RUNG: 12.05.2023; Views: 2881; Downloads: 34 Full text (14,33 MB) |
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5. Life cycle assessment of black and greywater treatment solutions for remote and sensitive areasAndreea Oarga-Mulec, Janez Turk, Petra Gerbec, Petter D. Jenssen, Katja Malovrh Rebec, Matjaž Valant, 2023, original scientific article Keywords: life cycle assessment, sanitation systems, sustainability, remote areas, circular economy Published in RUNG: 20.02.2023; Views: 2583; Downloads: 9 Full text (2,06 MB) This document has many files! More... |
6. SUSTAINABLE ASSESSMENT OF ENERGY RECOVERY FROM ORGANIC WASTE WITH A FOCUS ON WASTE FROM OLIVE OIL PRODUCTIONIrena Subotić, 2022, master's thesis Abstract: The need for a Circular Economy became more than obvious, and in line with that, technologies for utilization of renewables and waste-to-energy transformation have become of utmost importance in climate change mitigation. This master thesis deals with treating the waste after olive oil extraction and using anaerobic digestion to turn the waste into a biogas that later can be used for electricity and heat production. Since there are two options for location, it was necessary to use decision support models to remove subjectivity and bias from the decision-making process. After the decision was made, there was an economic analysis of a biogas plant project that later can be used for establishing a new company in Italy. According to the economic indicators, with a profit of 5.243.000 EUR after ten years and an investment return of less than five years, a biogas plant in Italy is a profitable investment. From the aspect of Circular Economy, the biogas plant successfully fits the concept. It has added value to the local community by turning one process by-product into primary material for another process, creating jobs and generating revenue for the municipal budget while preserving natural resources. Keywords: circular economy, decision support models, biogas, strategic management Published in RUNG: 11.07.2022; Views: 2875; Downloads: 72 Full text (2,14 MB) |
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9. REGIONAL POTENTIAL FOR SUSTAINABLE ENERGY SUPPLY IN CROATIA : MASTER'S THESISStefan Subotić, master's thesis Abstract: The master thesis aims to find the optimal model for a new energy company that considers regional potential, supports sustainable development, and fits the circular economy concept in a region. The idea of sustainable development is crucial today when we have more city areas and less countryside around the globe. Increased global population, industrial trends and modern living style are some of the reasons why the burden on our environment is more significant than ever in the history of humanity. The idea is to launch the new company in the Croatian region Osijek-Baranja, which is less developed and not attractive to tourists. A newly established company will produce electric energy from renewable energy sources. The multi-criterion decision support methods were used to determine the optimal energy source between wind, biogas and sun. Results show that the biogas has the most significant sustainable potential in chosen boundary conditions. The cash flows and other economic indicators are shown for a farm of 500 milking cows in the chosen region as a source of biogas. The risk assessments method estimated the boundaries of the company success and adaptability to possible changes. One of the critical aspects of the project is the company's organizational structure, where a vertical hierarchy with a flexible and fluid, circular organization model with network culture was proposed. Clear communication about the project will help establish trust with the local community. Based on the biogas plant, the proposed company reduces biodegradable waste in the green energy production process. It is shown quantitatively that besides being economically sustainable, it also suits the region's potential, supports energy self-supply, and involves local people - it aims to the long-term sustainable growth of the region, rather than short-term capital growth. Keywords: Circular economy, sustainable development, regional potential, renewable energy sources, company structure, communication Published in RUNG: 18.02.2022; Views: 3489; Downloads: 75 Full text (2,75 MB) |
10. Regenerating the historic urban landscape through circular bottom-up actions: the urban seeding process in RijekaMarco Acri, Saša Dobričić, Maja Debevec, 2021, original scientific article Abstract: The increasing pressure on urban resilience and the parallel interest in the preservation of the Historic Urban Landscape (HUL) have opened new frontiers of research that find, in the principles of the circular economy, good responses. Cities need to remake themselves from pure consumption to more resilient and circular centers, finding inspiration in their cultural and natural heritage and the history that generated it. The City of Rijeka, Croatia, one of the partners in the CLIC project (an EU-funded Horizon 2020 research project entitled “Circular models Leveraging Investments in Cultural heritage adaptive reuse”), represents an exceptional example of how to manage the change from an industrial port city to a more sustainable and citizen-oriented living space, looking at the potentials of the cultural and historical layers as opportunities for the population. The City of Rijeka, aware of such potentials, applied successfully as a European Capital of Culture 2020 (ECoC 2020), while unlikely facing the negative impacts of the COVID-19 pandemic. In Rijeka, thanks to the CLIC Heritage Innovative Partnership (HIP) program, the efforts to associate the circular economy and historic urban landscape benefit from an exceptional local awareness of the urban cultural and natural heritage, permitting the elaboration of the cultural corridor concept. By using the historical river of the city, the Rječina, as a connecting line of several heritage assets leading toward the Sea waterfront, the cultural corridor represents a space of culture creation based on continuity and proximity, where all citizens can securely reappropriate dismissed parts of the city, similar to the commons’ management practice. The cultural corridor has been imagined as a spatial implementation model that needs actions to be actuated. A set of actions was designed through the urban seeding process, tested in a workshop methodology, meant to address the HUL regeneration through an awareness-raising and cocreation approach by codesigning through situated learning, possible permanent or temporary actions, activities, assets to be replicated in the corridor and, per extension, in the entire city. This article will explain the way the cultural corridor concept and urban seeding were generated in the City of Rijeka, giving evidence of the motivations and the proposals made in parallel with the existing initiatives of the city and its cultural movements. Keywords: urban regeneration, historic urban landscape, circular economy, adaptive reuse, cultural corridor, urban seeding Published in RUNG: 08.06.2021; Views: 2819; Downloads: 139 Link to full text This document has many files! More... |