Iskanje po katalogu digitalne knjižnice

Opis: Waste-to-energy (WtE) is a key part of modern waste management. In the European Union, approximately 500 WtE plants process more than 100 million tons of waste yearly, while globally, more than 2700 plants handle over 500 million tons. Roughly 20% of the waste processed is bottom ash (BA). However, this ash can contain heavy metals in concentrations that may render it hazardous. This paper presents a study focusing on stabilizing municipal solid waste incineration BA using simple and industrially viable treatments. The Slovenian WtE plant operator wishes to install the stabilization process; thus, the samples obtained from the plant were treated (1) with a CO2 gas flow, (2) with water spraying, and (3) with a combination of water spraying and a CO2 gas flow under laboratory conditions. Thermodynamic calculations were applied to define potential reactions during the treatment processes in the temperature range from 0 to 100 ◦C and to define the equilibrium composition of the treated ash with additions of CO2 and water. The standard leaching test EN 12457-4 of treated ash shows a reduction of over 40% in barium concentration and over 30% in lead concentration in leachates.
Ključne besede: heavy metals, waste-to-energy, bottom ash, leachate, reuse
Objavljeno v DKUM: 10.03.2025; Ogledov: 0; Prenosov: 6
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Opis: This article examines the impact of financial support mechanisms and geopolitical factors on the profitability of investments in solar power plants within Slovenia. The European Union’s energy policy prioritizes increases in renewable energy sources, aiming to reduce dependency on unstable and volatile fossil fuel markets. Solar power plants play a vital role in this transition. The energy policy framework also includes mechanisms and support systems to operate such facilities. This article analyzes electricity price trends over the past decade and addresses which support type—guaranteed purchase or operational support—has proven more profitable for investments in solar power plants up to 50 kW in Slovenia, considering economic and geopolitical influences on the electricity market. Although the global energy market has been affected by various significant events in recent years, it was found that the COVID-19 pandemic had minimal impact on the electricity market. In contrast, the onset of the conflict in Ukraine has contributed to rising electricity prices and has influenced the support dynamics essential for the development and sustainability of renewable energy systems. Analyses from the past decade indicate a higher return on investment in solar power plants when operational support mechanisms are chosen over guaranteed purchase support.
Ključne besede: renewable energy sources, solar power plants, support system, investment profitability factors, electricity price
Objavljeno v DKUM: 16.12.2024; Ogledov: 0; Prenosov: 10
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Opis: Contemporary societies, whether they have reached advanced levels of economic and social development or are still developing, need to prioritise the implementation of circular economy practices. This will facilitate the shift towards regenerative, sustainable, and closed-loop industrial systems. For now, there are some efforts to encourage patterns of production and consumption through changes in economic trends, development of institutional frameworks, harmonising regulations in the field of environmental protection, and raising the level of social awareness to achieve, above all, greater efficiency of resources. Extensive literature that deals with monitoring the implementation of the circular economy already indicates the existence of numerous barriers in this process but also notices some incentives for raising the degree of circularity of the observed systems. In this paper, the question of whether a single value can represent the level of circularity of the chosen material/product chain is researched. An overview of barriers and drivers for implementing circular economy strategies is given to structure a proper metric framework in correlation to the research question. The objective was to simplify the monitoring of circularity by developing a unique index for comparing material/product chains in similar systems. This was accomplished by using the circular material use (CMU) rate introduced in the European Union and modifying it for financial data calculation. As a result, the circular economy index, which covers all 9R strategies (CEIR), is obtained. The practical verification of model applicability was shown by determining the degree of circularity achieved for passenger cars in the four observed EU countries.
Ključne besede: barriers, 9R framework, circular material use rate, circular economy index, passenger cars
Objavljeno v DKUM: 19.03.2024; Ogledov: 296; Prenosov: 34
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Opis: European Union Directive 2008/98/EC sets the priority hierarchy of the prevention of waste, re-using waste, recycling waste, waste recovery, and waste disposal. Although every one of us is in daily contact with waste, we do not have the knowledge that can lead us to the sound management of waste from the beginning, before products are identified as waste. Zero waste is a fundamental concept of the sustainable community of the future. It is a phrase frequently used by politicians seeking to upgrade the municipal solid waste management systems in their communities. In this manner, the responsibility of zero waste is given to the waste management process instead of to householders. Householders then equate waste prevention with recycling and the proper waste management of the collectors, public services, or waste management company. In reality, zero waste starts with each one of us at home. Households should aim to reduce consumption and undertake repairs to extend the life span of products. Behaviour change can only start with knowledge. In reality, waste prevention does not include recycling. Recycling leads to a combined reduction of waste brought to landfill and raw material extraction. The present paper evaluates household waste to clarify the facts. It analyses the composition of three streams: municipal solid waste, separately collected packaging waste, and bulky waste in different regions of Slovenia. The research defines waste into five different categories. The first category is waste that can and should be avoided. The second category is waste that can be re-used. Further on, the research expands by researching the market of the third category that defines recyclables, which waste can be recycled; the last two categories are the waste that we are fighting with at the end of the waste management process, either to make it to the waste-to-energy process or to comply with landfill restrictions. At the end of the research, we summarize the situation of household waste in 2018. Our goal is to reduce the quantity of waste, making only waste that can be recycled. If we consider waste prevention to be a fight against waste, we can put our plan in place by taking the first step: getting to know our enemy.
Ključne besede: municipal solid waste, zero waste, recycling, lightweight packaging waste, waste management, material recovery
Objavljeno v DKUM: 05.12.2023; Ogledov: 397; Prenosov: 8
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Ključne besede: CFD, combustion, wood pellets, air staging, flue gas recirculation
Objavljeno v DKUM: 05.09.2023; Ogledov: 391; Prenosov: 15
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