LEE- Enerji Bilim ve Teknoloji-Doktora

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http://hdl.handle.net/11527/19271

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Konu "Biomass energy" ile LEE- Enerji Bilim ve Teknoloji-Doktora'a göz atma
  • Öge
    Simulation and life cycle assessment of combined bioheat and biopower plant using hungary oak (Quercus frainetto L.) coppices as a feedstoc
    (Graduate School, 2024-02-16) Tolon, Fahriye Enda ; Karaosmanoğlu, Filiz ; 301092010 ; Energy Science and Technology
    Almost zero-emission woody biomass resources are vital for the decarbonization of energy while effectively using them as a product of sustainable forest management in energy production, especially in facilities such as for instance cogeneration plants. In cogeneration facilities, which aim to obtain thermal and mechanical energy simultaneously during the energy production process while producing electrical energy using woody biomass, heat energy is also produced by using some of the heat that emerges as a result of the process. This integrated energy production approach aims to minimize environmental impacts by increasing resource efficiency, thus providing a sustainable energy production model. Cogeneration facilities that use biomass as raw material are collectively called bioheat and biopower facilities. In Turkey's energy sector, the use of woody biomass, especially resources such as oak coppices, which have a significant share in forest assets, is essential in terms of Turkey's 2053 Net Zero Emission Target and sustainable energy production. In this context, the use of woody biomass in Turkey's energy policies will contribute to energy security by increasing diversity among renewables. Obtaining energy from woody biomass promotes sustainable management of biomass resources and enables the formation of a strategy to protect forest ecosystems. Turkey's focus on woody biomass resources such as oak coppices both supports local energy production and demonstrates the ability to lower carbon footprint of energy production processes from biomass. Sustainable management of forest and biomass production's energy intensity make life cycle assessment (LCA) environmentally necessary. LCA in energy production represents a holistic analytical approach that covers all stages of an energy source, namely feedstock extraction, energy production, energy use and waste management processes. Thus, it contributes to minimizing environmental impacts and developing a sustainable energy production model. This methodology provides a perspective on sustainability by assessing environmental, economic and social effects of an energy source from start to finish. First, during the extraction or production of the energy source, factors for instance the use of natural resources and harvesting of biomass are taken into account. Environmental impacts that occur at this stage include elements such as soil erosion, water pollution or biodiversity loss. During the production phase, the processes of processing, refining or transforming the energy source are evaluated. In these processes, factors such as use of energy, greenhouse gas emissions (GHGs) and waste production are examined. Environmental impacts during the production phase generally differ based on the kind of energy source and the technology used. In the usage phase, the consuming of energy resources and the operation of the facilities where energy production takes place are evaluated. Environmental aspects including the energy source's carbon emissions and its impact on the quality of the air and water are included at this stage. In addition, the economic impacts of the energy source, energy costs and employment creation potential are also evaluated. In the waste stage, the processes where the energy production process ends and waste products are managed are examined. It includes environmental and economic factors such as disposal processes, recycling possibilities, waste storage or disposal methods. In this thesis study, the simulation and LCA of a combined heat and power (CHP) plant burning woody biomass was carried out. The study is essential in terms of energy sustainability and covers the three basic dimensions of energy sustainability: energy security, energy equality and energy systems' sustainability in terms of the environment. Turkey's energy outlook, energy production from wood, woody biomass supply chain (BSC), modeling of combined bioheat and biopower (CBHBP) power plants burning woody biomass and analysis of life cycle scenarios of generation of energy from biomass constitute the subheadings of the literature research of the thesis study. As part of the theoretical analysis of this thesis, process simulations were created for four different case studies using Aspen Plus V12.1 software, and together, SimaPro V9.5 software was used in the LCA of nine various scenarios to examine the effects on the environment of the related bioheat and biopower plant process parameters. To characterize the production of bioheat and biopower together, process simulations of cases with 1, 2, 5 and 10-megawatt electricity (MWe) installed power using the technique for producing steam using direct combustion technology and the classical Rankine cycle were created using an eco-design methodology by Aspen Plus V12.1 software. Oak coppice forests, which have a significant share in Turkey's Forest Assets, were chosen as the raw material source of the relevant cases. A raw material sample of Hungarian Oak (Quercus Frainetto L.) was taken from the Oak Coppice forests in Kırklareli, Vize district of the Marmara Region, turned into oak chips and characterized. Bioheat and biopower process simulation outputs were used together in the LCA study. The purpose and the study's scope were determined, inventory analysis was made, and then the life cycle inventory (LCI) with the created scenarios was prepared using SimaPro V9.5 software. The life cycle system boundary that is subject to the thesis begins with the oak coppices harvesting in the forest and ends with the transmission of electricity and heat to the grid. Nine different scenarios were created according to production capacity, supply chain management and waste management system criteria to evaluate how different alternatives for the system would affect the environment and to help with decision-making. In the study, 1 kilowatt-hour (kWh) of biopower and 1 kWh of bioheat were taken for comparisons of functional unit production capacities, carbon footprint and water footprint. For supply chain management comparisons, functional unit was taken as 1 ton of oak chip and 1 kg of oak ash and in the waste management system comparison. To determine environmental impact "ReCiPe 2016 Endpoint (H)/World 2010 (H)" impact assessment method was chosen as the midpoint method, and "ReCiPe 2016 Endpoint (H)/World 2010 (H/A)" impact assessment method was selected as the endpoint method. "IPCC GWP100" method was chosen as the method for carbon footprint calculation and "AWARE" technique was chosen for water footprint calculation. Life cycle comparisons of the scenarios include carbon and water footprint results of all scenarios with midpoint characterization, midpoint normalization, damage assessment, damage assessment by impact category, weighting, single score, and single score results by impact category. The selection of the best scenarios was made by looking at production capacity, carbon footprint, water footprint results, supply chain benchmarking results and waste management results.