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Drobez R.,Scientific Research Center Bistra Ptuj | Novak Pintaric Z.,University of Maribor | Pahor B.,Perutnina Ptuj | Kravanja Z.,University of Maribor
Asia-Pacific Journal of Chemical Engineering | Year: 2011

The objective of this work was to perform simultaneous heat integration and the synthesis of biogas process based on the mixed-integer nonlinear programming (MINLP) model. A synthesis model recently developed by Drobež et al. [R. Drobež, Z. Novak Pintarič, B. Pahor, Z. Kravanja. Chem. Biochem. Eng. Q, 2009; 23, 445-459] has been upgraded for simultaneous heat integration. An industrial case study was solved in order to describe the mathematical model and to illustrate the heat-integrated MINLP synthesis approach. The optimal solution indicates that during the synthesis of biogas process and when selecting the best auxiliary facilities significant benefit can be obtained if the selected process and auxiliary facilities are heat integrated. In this way almost the complete consumption of hot utility and 1/3 of cold utility can be saved, and thus most of the electricity and heat produced in the cogeneration system from biogas can be sold as surplus to the distribution networks. The proposed optimal synthesis of heat-integrated biogas process may improve a company's economic performance and significantly reduce its environmental impact by converting environmentally harmful organic and animal wastes into valuable products. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd. Source

Kostevsek A.,Scientific Research Center Bistra Ptuj | Petek J.,Local Energy Agency Spodnje Podravje | Cucek L.,University of Maribor | Klemes J.J.,University of Pannonia | Varbanov P.S.,University of Pannonia
Applied Thermal Engineering | Year: 2015

The decarbonisation of energy systems is one of the important issues of the present energy policies. One of the ways of achieving this is to focus on local energy systems, thus ensuring as much as possible their heat and power self-sufficiency by applying local renewable resource integration and transformation of the renewable energy. Increasing the share of renewables within the local energy balance could be accomplished by using a variety of approaches. One possibility is combining the Locally Integrated Energy Sectors' concept with the novel management and organisation of a renewables-based network. As a first priority, the proposed comprehensive approach focuses on increasing the energy efficiency of municipal heat and power systems using the Locally Integrated Energy Sectors' concept, which is followed by the integration of renewable energy sources with the establishment of a renewable-based network. The proposed approach is illustrated by a case study of district heating based on wood biomass for the municipality Ormož, Slovenia by integrating various end-users from different sectors. © 2015. Source

Biochar as a soil amendment and carbon sink becomes in last period one of the vast, interesting product of slow pyrolysis. Simplest and most used industrial process arrangement is a production of biochar and heat at the same time. Proposed mass and heat balance model consist of heat consumers (heat demand side) and heat generation-supply side. Direct burning of all generated uncondensed volatiles from biomass provides heat. Calculation of the mass and heat balance of both sides reveals the internal distribution of masses and energy inside process streams and units. Thermodynamic calculations verified not only the concept but also numerical range of the results. The comparisons with recent published scientific and vendors data prove its general applicability and reliability. The model opens the possibility for process efficiency innovations. Finally, the model was adapted to give more investors favorable results and support techno-economic assessments entirely. © 2016 Elsevier Ltd. Source

Kostevsek A.,Scientific Research Center Bistra Ptuj | Petek J.,Local Energy Agency Spodnje Podravje | Cucek L.,University of Maribor | Pivec A.,Scientific Research Center Bistra Ptuj
Energy | Year: 2013

Effectively implementing various energy and environmental policies contributes to the acceleration of energy performance, a reduction in negative environmental impacts, and increased deployment of renewable resources. The MEEMS (municipal energy and environmental management system) performs the almost inconceivable role of accomplishing prerequisite targets at the national level and, consequently, the European and World levels also. Therefore, a proper infrastructure for MEEMS needs to be effectively applied in order to implement policy initiatives. A novel organisational framework of MEEMS is proposed and is constituted upon three pillars: integration of the municipal metabolism approach, the KBS (knowledge-based system), and the MTIS (municipal technology innovation system). By properly addressing the dynamics of the MEES (municipal energy and environmental system), and the new conceptual organisation of MEEMS, a need for the inclusion of innovative elements can be defined regarding support mechanisms. Integration of the end-user approach defines the fundamental orientation of modern MEEMS. This new concept paves a pathway towards an intelligent energy and environmental system. This paper describes an implementation of the new conceptual design of MEEMS within the urban municipality energy system of Ptuj, Slovenia. © 2013 Elsevier Ltd. Source

Kostevsek A.,Scientific Research Center Bistra Ptuj | Cizelj L.,Jozef Stefan Institute | Petek J.,Local Energy Agenc Spodnje Podravje | Cucek L.,University of Maribor | And 3 more authors.
Chemical Engineering Transactions | Year: 2013

The current contribution builds upon the locally-integrated energy sectors (LIES) concept. The LIES concept (Perry et al., 2008) extended the TS methodology (Dhole and Linnhoff, 1993) developed initially for industrial complexes mainly. LIES (Varbanov and Klemeš, 2011) offer a further extension of Total Site (TS) concept to accommodate collaboration between industry and local communities. This concept can be especially attractive for the municipalities abundant with natural resources. Recent research leads towards integration of energy users and energy producers over larger geographical area up to regional scale. The design optimisation is investigated for local and regional energy supply at municipal and higher level to accelerate the use of renewable resources within rural municipalities. The demand levels and patterns of the involved energy user types are described, followed by the selection of promising renewable and fossil resources. The variability of renewables makes it necessary to accommodate varying availability by optimal demand side management, appropriate clustering of energy sources and sinks, as well as using energy storage. Copyright © 2013, AIDIC Servizi S.r.l. Source

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