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1.
An innovative approach to organizational changes for sustainable processes : a case study on waste minimization
Eva Krhač Andrašec, Tomaž Kern, Benjamin Urh, 2023, izvirni znanstveni članek

Opis: It is necessary to adapt constantly to the business environment with its changing demands. Understanding the objectives, scope, and limitations of actual process changes is crucial, and can be achieved with numerous measures, methods, and techniques. This research demonstrates an innovative approach to organizational changes to enable sustainable processes. In the first part of this research, relevant measures, methods, and techniques are selected through an in-depth literature review. Then, an international online questionnaire is executed among 213 enterprises from four countries. In the last part of this research, the developed approach is tested for the example of waste minimization in the process of developing coatings. Based on the analysis of the survey questionnaire, the usability and benefits of various measures are demonstrated, namely from the point of view of their positive impact on structural and operational efficiency indicators. At the end of the article, a case study presents the success of the innovative approach in terms of 88% waste minimization and up to 48% time and cost reductions in the process of developing coatings. The proposed approach enables better choices to be made and the more efficient use of various measures, which can lead to more sustainable processes and improve the efficiency of enterprises.
Ključne besede: organizational changes, key performance indicators, measures, methods and techniques, sustainable processes, waste minimization
Objavljeno v DKUM: 02.04.2024; Ogledov: 67; Prenosov: 6
.pdf Celotno besedilo (2,34 MB)
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2.
The Evaluation of Torrefaction Efficiency for Lignocellulosic Materials Combined with Mixed Solid Wastes
Maja Ivanovski, Darko Goričanec, Danijela Urbancl, 2023, izvirni znanstveni članek

Opis: The paper presents the results of research aimed at evaluating the possibility of using selected biomass wastes to produce solid biofuels. In this work, the thermochemical properties of two lignocellulosic biomasses, namely, miscantshus (Miscanthus × Giganteus) and hops (Humulus lupulus), and non-lignocellulosic biomass, namely, municipal solid waste, and their mixtures (micanthus + municipal solid waste and hops + municipal solid waste) were studied using the torrefaction process as the main method for investigation. The effects of various torrefaction temperatures (250, 300, and 350 °C) and times (30 and 60 min) were evaluated. Proximate and ultimate analyses were performed on the torrefied samples. The following can be stated: as the torrefaction temperature and time increased, mass and energy yields decreased while the higher heating values (HHVs) and fuel ratios (FRs) increased, together with carbon contents (C). In addition, energy on return investment (EROI) was studied; the maximum EROI of 28 was achieved for MSW biochar at 250 °C for 30 min. The results of studying greenhouse gas emissions (GHGs) showed a reduction of around 88% when using torrefied biochar as a substitute for coal. In sum, this study shows that torrefaction pre-treatment can improve the physicochemical properties of raw biomasses to a level comparable with coal, and could be helpful in better understanding the conversion of those biomasses into a valuable, solid biofuel.
Ključne besede: torrefaction, waste biomass, renewable energy, fuel ratio, greenhouse gas emission, GHG
Objavljeno v DKUM: 29.03.2024; Ogledov: 53; Prenosov: 2
.pdf Celotno besedilo (3,69 MB)
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3.
From nature to lab : sustainable bacterial cellulose production and modification with synthetic biology
Vid Potočnik, Selestina Gorgieva, Janja Trček, 2023, pregledni znanstveni članek

Opis: Bacterial cellulose (BC) is a macromolecule with versatile applications in medicine, pharmacy, biotechnology, cosmetology, food and food packaging, ecology, and electronics. Although many bacteria synthesize BC, the most efficient BC producers are certain species of the genera Komagataeibacter and Novacetimonas. These are also food-grade bacteria, simplifying their utilization at industrial facilities. The basic principles of BC synthesis are known from studies of Komagataeibacter xylinus, which became a model species for studying BC at genetic and molecular levels. Cellulose can also be of plant origin, but BC surpasses its purity. Moreover, the laboratory production of BC enables in situ modification into functionalized material with incorporated molecules during its synthesis. The possibility of growing Komagataeibacter and Novacetimonas species on various organic substrates and agricultural and food waste compounds also follows the green and sustainable economy principles. Further intervention into BC synthesis was enabled by genetic engineering tools, subsequently directing it into the field of synthetic biology. This review paper presents the development of the fascinating field of BC synthesis at the molecular level, seeking sustainable ways for its production and its applications towards genetic modifications of bacterial strains for producing novel types of living biomaterials using the flexible metabolic machinery of bacteria.
Ključne besede: acetic acid bacteria, bacterial cellulose, sustainable production, agricultural waste, food waste, genetic engineering, synthetic biology, biomaterial, Komagataeibacter, Novacetimonas
Objavljeno v DKUM: 28.03.2024; Ogledov: 74; Prenosov: 10
.pdf Celotno besedilo (5,82 MB)
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4.
Exploring the properties of the torrefaction process and its prospective in treating lignocellulosic material
Maja Ivanovski, Aleksandra Petrovič, Darko Goričanec, Danijela Urbancl, Marjana Simonič, 2023, pregledni znanstveni članek

Opis: The main objective of this review is to present the latest research results regarding the importance of the torrefaction process for different biomass materials in the last 12-year period. Despite the fact that the potential of renewable energy sources has been analyzed, research regarding that of energy derived from waste biomass still remains in the infancy state. Torrefaction is known to be one of the most effective methods for enhancing the energy efficiency of biomass. Among different types of torrefactions, the focus in this study is mostly on dry torrefaction. The influential factors, like temperature and residence time, and physico-chemical properties of torrefied products, and the prospective of torrefaction due to its reduced impact on environment, are discussed in-depth. This review provides valuable insights into the torrefaction process, which is conducive to upgrading biomass for achieving net zero carbon emissions, as it has been stated in several works that torrefied biomass can be used instead of coal.
Ključne besede: torrefaction, lignocellulosic biomass, waste biomass, biomass properties
Objavljeno v DKUM: 22.03.2024; Ogledov: 76; Prenosov: 3
.pdf Celotno besedilo (1,74 MB)
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5.
Obtaining the synthetic fuels from waste plastic and their effect on cavitation formation in a common-rail diesel injector
Luka Kevorkijan, Amalia Palomar-Torres, Eloisa Torres Jiménez, Carmen Mata, Ignacijo Biluš, Luka Lešnik, 2023, izvirni znanstveni članek

Opis: The presented paper addresses two significant issues of the present time. In general, the studies of the effect of synthetic fuels on cavitation formation and cavitation erosion prediction in the nozzle tip of common-rail diesel injectors were addressed. The first problem is plastic waste, which can have a significant negative environmental impact if not treated properly. Most plastic waste has high energy value, so it represents valuable material that can be used in resource recovery to produce various materials. One possible product is synthetic fuel, which can be produced using thermal and catalytic pyrolysis processes. The first issue addressed in the presented paper is the determination of fuel properties since they highly influence the fuel injection process, spray development, combustion, etc. The second is the prediction of cavitation development and cavitation erosion in a common-rail diesel injector when using pyrolytic oils from waste plastic. At first, pyrolytic oils from waste high- and low-density polyethylene were obtained using thermal and catalytic pyrolysis processes. Then, the obtained oils were further characterised. Finally, the properties of the obtained oils were implemented in the ANSYS FLUENT computational program and used in the study of the cavitation phenomena inside an injection nozzle hole. The cavitating flow in FLUENT was calculated using the Mixture Model and Zwart-Gerber-Belamri cavitation model. For the modelling of turbulence, a realisable k–ε model with Enhanced Wall Treatment was used, and an erosion risk indicator was chosen to compare predicted locations of cavitation erosion. The results indicate that the properties of the obtained pyrolytic oils have slightly lower density, surface tension and kinematic viscosity compared to conventional diesel fuel, but these minor differences influence the cavitation phenomenon inside the injection hole. The occurrence of cavitation is advanced when pyrolytic oils are used, and the length of cavitation structures is greater. This further influences the shift of the area of cavitation erosion prediction closer to the nozzle exit and increases its magnitude up to 26% compared to diesel fuel. All these differences have the potential to further influence the spray break-up process, combustion process and emission formation inside the combustion chamber.
Ključne besede: plastic waste, synthetic fuels, pyrolytic oils, common-rail, cavitation, erosion, transient simulation
Objavljeno v DKUM: 18.03.2024; Ogledov: 74; Prenosov: 5
.pdf Celotno besedilo (4,55 MB)
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6.
Transitioning towards Net-Zero Emissions in Chemical and Process Industries : A Holistic Perspective
Peter Glavič, Zorka Novak-Pintarič, Helena Levičnik, Vesna Dragojlović, Miloš Bogataj, 2023, pregledni znanstveni članek

Opis: Given the urgency to combat climate change and ensure environmental sustainability, this review examines the transition to net-zero emissions in chemical and process industries. It addresses the core areas of carbon emissions reduction, efficient energy use, and sustainable practices. What is new, however, is that it focuses on cutting-edge technologies such as biomass utilization, biotechnology applications, and waste management strategies that are key drivers of this transition. In particular, the study addresses the unique challenges faced by industries such as cement manufacturing and highlights the need for innovative solutions to effectively reduce their carbon footprint. In particular, the role of hydrogen as a clean fuel is at the heart of revolutionizing the chemical and process sectors, pointing the way to cleaner and greener operations. In addition, the manuscript explores the immense importance of the European Green Deal and the Sustainable Development Goals (SDGs) for the chemical industry. These initiatives provide a clear roadmap and framework for advancing sustainability, driving innovation, and reducing the industry's environmental impact, and are a notable contribution to the existing body of knowledge. Ultimately, alignment with the European Green Deal and the SDGs can bring numerous benefits to the chemical industry, increasing its competitiveness, promoting societal well-being, and supporting cross-sector collaboration to achieve shared sustainability goals. By highlighting the novelty of integrating cutting-edge technologies, addressing unique industrial challenges, and positioning global initiatives, this report offers valuable insights to guide the chemical and process industries on their transformative path to a sustainable future.
Ključne besede: net zero, energy, process industries, emissions, climate, chemicals, biomass, waste, cement, metals
Objavljeno v DKUM: 19.02.2024; Ogledov: 145; Prenosov: 2
.pdf Celotno besedilo (894,06 KB)
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7.
Food Waste to Energy through Innovative Coupling of CHP and Heat Pump
Jan Drofenik, Danijela Urbancl, Darko Goričanec, Zdravko Kravanja, Zorka Novak-Pintarič, 2023, izvirni znanstveni članek

Opis: This paper presents the conceptual design of a technological solution for the efficient conversion of food waste into heat and power. The distribution and composition of food loss and waste at different stages of the food supply chain in Slovenia and their potential for biogas production were determined. It was found that more than 50% of food waste comes from households. Therefore, a small plant was designed to convert food waste into biogas, which was innovatively coupled with a combined heat and power (CHP) unit and a heat pump. This doubles the amount of heat generated compared to conventional cogeneration. Based on the capacity of a micro commercial CHP unit, 3330 households (about 8000 residents) would supply food waste. The heat generated could replace 5% of the natural gas used for domestic water heating. The payback period would be 7.2 years at a heat price of about 80 EUR/MWh, however, for municipalities with more than 40,000 inhabitants the payback period would be reduced to less than 3 years. The cost price of the heat generated by this system would be about 25 EUR/MWh, taking into account the government subsidy for the operation of the CHP unit.
Ključne besede: food waste to energy, biogas, combined heat and power, CHP, heat pump, efficiency, conceptual design, preliminary economic assessment, sensitivity analysis
Objavljeno v DKUM: 16.02.2024; Ogledov: 2975; Prenosov: 6
.pdf Celotno besedilo (19,44 MB)
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8.
Rationalisation of costs in the collection, segregation and transport of municipal waste
Paweł Zając, Ivona Bajor, Matevž Obrecht, Stanisław Ejdys, 2023, izvirni znanstveni članek

Opis: The article contains answers to three "why" questions: - why the waste management system still does not bring the expected results, and the Polish state is one of the lowest-ranking in the European score regarding the amount of segregated waste; - why the sale of selected secondary raw materials and their material reuse in production processes do not cover the costs related to waste management; - why it does not bring additional profits. The article is based on research conducted in Wroclaw from 1998 to 2018. There is a cost model that can be adapted to similar cases. The article deals with removing organisational and/or technical reasons causing the stagnation of selective waste collection.
Ključne besede: waste, mixed, sorting, fee, management
Objavljeno v DKUM: 16.02.2024; Ogledov: 82; Prenosov: 8
.pdf Celotno besedilo (698,09 KB)
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9.
Converting waste into products and energy using complete circular economy and the hydrogen effect technique to reduce dependence on natural gas
Anita Kovač Kralj, 2023, izvirni znanstveni članek

Opis: Conversion of waste into products and energy has the potential to reduce CO2 emis-sion through implementation of a complete circular economy and utilisation of the hy-drogen effect technique. This study considers the novelties of the hydrogen effect tech-nique, which incorporates an upgraded input unit mathematical model. It includes real-simulated results obtained using an Aspen Plus & REG; simulator, and enlarged production. This technique is developed for optimal municipal solid waste (MSW) combustion, gas-ification, and reforming, presented as an upgraded input unit for syngas production, which can reduce CO2 emissions by 3 & BULL;106 kmol a-1. This approach is exemplified by utilizing existing methanol and dimethyl ether production processes from natural gas, as they can be achieved and exceeded using MSW with varying hydrogen amounts. The optimal upgraded methanol and dimethyl ether production processes can increase pro-duction by 47 % and 16 %, including only the upgraded input unit, as well as decrease the temperature in the product reactors by 30 & DEG;C.
Ključne besede: waste gasification, flue gas, syngas, hydrogen, circular economy, combustion
Objavljeno v DKUM: 13.02.2024; Ogledov: 147; Prenosov: 8
.pdf Celotno besedilo (524,98 KB)
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10.
An analysis of the responsibility for zero waste
Ivana Tršelič, Daniel Rolph Schneider, Niko Samec, Filip Kokalj, 2019, izvirni znanstveni članek

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: 233; Prenosov: 6
.pdf Celotno besedilo (463,42 KB)
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