1. An innovative approach to organizational changes for sustainable processes : a case study on waste minimizationEva Krhač Andrašec, Tomaž Kern, Benjamin Urh, 2023, original scientific article Abstract: 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. Keywords: organizational changes, key performance indicators, measures, methods and techniques, sustainable processes, waste minimization Published in DKUM: 02.04.2024; Views: 286; Downloads: 19 Full text (2,34 MB) This document has many files! More... |
2. Optimization of the distribution network operation by integration of distributed energy resources and participation of active elementsNevena Srećković, 2020, doctoral dissertation Abstract: Distribution Networks (DNs) are evolving from a once passive to an active part of the electricity network. This evolution is driven by the current political and environmental decisions, Directives and Incentives, as well as the technological development, observed in the everincreasing integration of renewable energy resources, advanced network control and measurement devices, the upcoming energy exibility market, etc. This Doctoral Thesis deals with the problem of optimization of the technical aspects of a DN operation, enabled by the proliferated integration of the photovoltaic systems (PV) and other active devices. The main objective of the Thesis is the optimization of a DN operation in terms of minimization of electrical energy losses while ensuring the proper voltage profiles and preventing thermal overloadingof lines. Therefore, three Differential Evolution-based optimization procedures were developed and tested on real medium and low voltage DNs. The first methodology determines the optimal rooftop surfaces for the installation of PV systems, yielding minimum annual energy losses. It is based on the simultaneous consideration of high-resolution spatio-temporal solar and PV potential data, as well as long-term measured profiles of consumption and generation of electrical energy within the network of a given configuration. The second algorithm minimizes network losses in a time-discrete operation point, by determining the optimal operation of the following active elements: PV systems capable of cooperation in reactive power provision, On-Load Tap Changer equipped transformer substations and remotely controlled switches for network reconfiguration. The final algorithm was developed by a proper consolidation of the first two approaches, yielding the synergistic effects expressed as the increase of loss reduction and network exibility. The results of the performed case studies show that the locations of the highest suitability for PV installation with respect to the solar energy availability, are not necessarily the best choice from the network operation standpoint. Therefore, both standpoints should be considered simultaneously when choosing the rooftop surfaces for PV installation. Furthermore, by determining optimal hourly operation of the considered active elements, not only the additional reduction of annual network losses was achieved, but also increased accommodation of the PV systems that doesn't violate operation constraints. Keywords: distribution network, optimization of operation, active network elements, PV system placement, minimization of losses Published in DKUM: 11.06.2020; Views: 1867; Downloads: 422 Full text (44,58 MB) |
3. Microeconomics : an integrated approachDavid Besanko, Ronald Ray Braeutigam, higher education textbook Keywords: microeconomics, economic analyses, problematics, problem solving, theory of rational expectations, supply, demand, general equilibrium, consumer, opportunities, mathematical economy, input-output, costs, minimization, competitiveness, competitive advantage, market, application, monopolies, oligopolies, game theory, behavior, market structure, risk, informations, externalities, public goods, graphic methods, graph theory, textbooks, exercises, manuals Published in DKUM: 01.06.2012; Views: 2943; Downloads: 52 Link to full text |
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5. Improving the economic and environmental performances of the beet sugar industry in Slovenia: increasing fuel efficiency and using by-products for ethanolDamjan Krajnc, Miro Mele, Peter Glavič, 2007, original scientific article Abstract: This paper investigates the possibilities of attaining zero-waste emissions inthe case of sugar production. The case-studied sugar plant located in Slovenia reflected a typical plant, using traditional sugar production from beet. An investigation of the possible use of waste and by-products from sugarprocessing was carried out, in order to approach zero-waste from beet sugar processing. The sugar production process was simulated and optimization was carried out concerning energy utilization. Consumption of energy in the chosen sugar plant was lowered by simultaneous optimization of the evaporationand crystallization process. Changing the fuel type used in the case-studied sugar plant (replacement of heavy fuel oil with natural gas) produced a significant decrease in air emission. Opportunities in the sugar industry have been discovered for adapting to new market conditions through the optimization of combined sugar-ethanol production. The two proposed options have been economically and environmentally evaluated and compared. Keywords: kemična industrija, trajnostni razvoj, proizvodnja sladkorja, minimiranje porabe energije, evaporacija, etanol, chemical industries, sustainable development, sugar production, energy minimization, evaporation, ethanol, zero waste Published in DKUM: 01.06.2012; Views: 2699; Downloads: 104 Link to full text |
6. Water minimization in process industries: case study in beet sugar plantLea Žbontar Zver, Peter Glavič, 2005, original scientific article Abstract: In this article, an extended and combined systematic approach for water minimization in process industries is presented. Environmental, organizational and economic aspects of water minimization were taken into consideration. Systematic approach was developed and tested with the water minimization project in a sugar plant. A detailed survey of water and wastewater streams was carried out and several options for water minimization were proposed using the heuristic approach and considering the selection criteria like costs, technical ability, reliability, complexity, impact on process/product quality, secondary waste generation etc. The implementation of water minimization options could lower the fresh water consumption by 54.23 m3/h, reducing the total volume of water used by 69 % with the payback period of 5 days. At the end, some general directions and suggestions for water minimization in process industries are introduced. Keywords: chemical processing, sugar production, water consumption, minimization, cleaner production Published in DKUM: 01.06.2012; Views: 2882; Downloads: 89 Link to full text |
7. Synthesis of non-isothermal heat integrated water networks in chemical processesMiloš Bogataj, Miguel J. Bagajewicz, 2008, original scientific article Abstract: This paper presents a new approach for the simultaneous synthesis and optimization of heat integrated water networks. A new superstructure for heat exchanger network (HEN) synthesis is proposed. The procedure is based on mixed integer non-linear mathematical programming (MINLP). Four relevant examples are presented to illustrate various aspects of the proposed approach. Keywords: chemical processing, chemical process design, process water networks, water networks, wastewater minimization, heat integration, MINLP, HEN synthesis, superstructures, process synthesis Published in DKUM: 31.05.2012; Views: 2298; Downloads: 98 Link to full text |