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This study aims to investigate the physical and chemical characterization of six fly ash samples obtained from different municipal solid waste incinerators (MSWIs), namely grate furnaces, rotary kiln, and fluidized bed reactor, to determine their potential for CO2 and thermochemical energy storage (TCES). Representative samples were characterized via simultaneous thermal analysis (STA) in different atmospheres, i.e., N2, air, H2O, CO2, and H2O/CO2, to identify fly ash samples that can meet the minimum requirements, i.e., charging, discharging, and cycling stability, for its consideration as TCES and CO2-storage materials and to determine their energy contents. Furthermore, other techniques, such as inductively coupled plasma optical emission spectroscopy, X-ray fluorescence (XRF) spectrometry, X-ray diffraction (XRD), scanning electron microscopy, leachability tests, specific surface area measurement based on the Brunauer&ndash, Emmett&ndash, Teller method, and particle-size distribution measurement, were performed. XRF analysis showed that calcium oxide is one of the main components in fly ash, which is a potentially suitable component for TCES systems. XRD results revealed information regarding the crystal structure and phases of various elements, including that of Ca. The STA measurements showed that the samples can store thermal heat with energy contents of 50&ndash, 394 kJ/kg (charging step). For one fly ash sample obtained from a grate furnace, the release of the stored thermal heat under the selected experimental conditions (discharging step) was demonstrated. The cycling stability tests were conducted thrice, and they were successful for the selected sample. One fly ash sample could store CO2 with a storage capacity of 27 kg CO2/ton based on results obtained under the selected experimental conditions in STA. Samples from rotary kiln and fluidized bed were heated up to 1150 &deg, C in an N2 atmosphere, resulting in complete melting of samples in crucibles, however, other samples obtained from grate furnaces formed compacted powders after undergoing the same thermal treatment in STA. Samples from different grate furnaces showed similarities in their chemical and physical characterization. The leachability test according to the standard (EN 12457-4 (2002)) using water in a ratio of 10 L/S and showed that the leachate of heavy metals is below the maximum permissible values for nonhazardous materials (except for Pb), excluding the fly ash sample obtained using fluidized bed technology. The leachate contents of Cd and Mn in the fly ash samples obtained from the rotary kiln were higher than those in other samples. Characterization performed herein helped in determining the suitable fly ash samples that can be considered as potential CO2-storage and TCES materials.

Das Anwachsen der Bev��lkerung, unsere Abh��ngigkeit von fossilen Energietr��gern, Urbanisierung, unser Managementsystem der Energie und unsere Tendenz zu einem angenehmen Leben haben alle dazu gef��hrt, dass das Klima unserer Erde sich ��ndert. Um den Trend des Klimawandels einzud��mmen, sind schnelle, ernsthafte und korrekte globale Entscheidungen auf politischer Ebene erforderlich. Insbesondere die Umstellung auf erneuerbare Energiequellen, bevor der globale Temperaturanstieg gr����er als 2C ist, wodurch der Klimawandel ein irreversibler Prozess wird. Dies bringt eine erhebliche Gefahr f��r das menschliche Leben auf der Erde mit sich. Erneuerbare Energiequellen schwanken mit der Zeit, insbesondere die Sonnenenergie, von der alle anderen Energiequellen abh��ngig sind. Die Speicherung von Energie in der Zeit, in der die Sonne zur Verf��gung steht, ist daher notwendig, um Solarkraftwerke als nachhaltige Energielieferanten zu bewerten. Der thermochemische Energiespeicher (TCES) als eine moderne Technologie kann dazu beitragen die L��cke zwischen Angebot und Nachfrage zu schlie��en. Die ��bersch��ssige W��rme von CSP- oder anderen Anlagen k��nnen in chemischen Komponenten durch endotherme chemische Reaktionen gespeichert werden und bei Bedarf kann die gespeicherte W��rme durch exotherme chemische Reaktionen freigesetzt werden. Das CuO/Cu2O System ist ein potenzieller TCES-Kandidat f��r die Verwendung in CSP. Es gibt jedoch immer noch Herausforderungen dieses Systems, welche weitere Untersuchungen erfordern, um seine Implementierung im industriellen Ma��stab zu erm��glichen. Die Kinetik dieses Systems f��r die TCES wurde nicht gen��gend untersucht, was f��r die Skalierung dieses System von entscheidender Bedeutung ist. Daher wurden im Rahmen dieser Arbeit Untersuchungen durchgef��hrt, um die kinetischen Daten (Modell, Aktivierungsenergie und Frequenzfaktor) und den Einfluss des Partialdruckes auf die Oxidationskinetik (Freisetzung der Energie) zu identifizieren. Die Auswertung der Kinetik-Daten wurde mittels einer modelfreien Methode Namens ���non-parametric kinetics (NPK)��� durchgef��hrt. Eine weitere derzeit bestehende Herausforderung f��r die industrielle Implementierung der TCES sind die hohen Kosten der Chemikalien. Der Fokus der Forschung liegt derzeit an Rohstoffen oder dotierten Materialien. Ein Material, dass alle die TCES-Anforderungen aus technischen, ��kologischen und wirtschaftlichen Gesichtspunkten erf��llt, ist noch nicht verf��gbar. Nach unserem besten Wissen, wurde das Potential der Abf��lle bzw. Nebenprodukte der Industrie noch nicht untersucht. Daher wurden im Rahmen dieser Arbeit die Flugascheproben, die bei der Verbrennung von Siedlungsabf��llen (MSWI), Biomasse und Zellstoffen entstehen zum Ziel der Evaluierung Ihres Potentials als TCES und CO2 Speicher untersucht. Dar��ber hinaus werden verschiedene Systemintegrationen f��r zuk��nftige Studien und Bewertungen vorgestellt. Die Ergebnisse dieser Dissertation erm��glichen die Aufnahme von Nebenprodukten oder Abf��llen aus der Industrie in das Suchspektrum nach TCES-und CCS-Materialen. Dies beschleunigt die industrielle Umsetzung von TCES und macht TCES unter ��kologischen und ��konomischen Gesichtspunkten nachhaltig., Population increase, our dependency on fossil energy sources, massive urbanization, our managing system of energy sources, lack of economical technologies, and our tendency to have a more comfortable life have all contributed to the change in climate, which has already altered biological life on Earth. To mitigate the trend of climate change, fast, serious, and correct global decisions at the political level are needed, in particular for shifting to renewable energy sources, before the global temperature rise increases by 2C, above which climate change will be an irreversible process, resulting in considerable danger for human life on Earth. Renewable energy sources fluctuate in time, particularly solar energy, which is the origin of all other energy sources on Earth. Therefore, storing energy in the time when the sun is available is necessary for developing concentrated solar power (CSP) plants as sustainable energy suppliers and to compete against fossil-fuel energy sources. Thermochemical energy storage (TCES) as a modern technology, which is still under development, can contribute to bridge the gap between supply and demand by storing the excess heat from CSP plants or any other plant in chemical components through endothermic chemical reactions and releasing the stored heat when energy is needed. Storing energy is the key element for accelerating the shift to renewable energy sources. The CuO/Cu2O system is a potential TCES candidate for use in CSP; however, there are still unsolved challenges and knowledge of this system that require more investigations to accelerate its implementation on the industrial scale. The kinetics of this system have not gained enough attention. Furthermore, the knowledge about the kinetics for scaling up this system is vital. Therefore, investigations have been performed to identify the kinetics triplet (model, activation energy, and frequency factor) and the impact of partial pressure on the oxidation kinetics (releasing energy). Kinetics evaluations have been performed by the non-parametric kinetics (NPK) method. Another existing challenge for industrial implementation of TCES is the cost of chemicals. The focus of research regarding suitable materials for TCES lies on raw or doped material. In the frame work of this thesis, the potential of fly ash as a byproduct or waste, such as municipal solid waste (MSW), whose cost is low or almost minimal, from different industries such as paper, pulp, and industries were investigated. Owing to reaction of alkali metal oxides such as CaO in fly ash with CO2, the CO2 storage capacity of reactive fly ash with carbon dioxide in the dry and wet carbonation process in simultaneous thermal analysis (STA) was evaluated. The investigation performed within this thesis shows that some fly ash samples can be considered as TCES and carbon capture and storage (CCS) materials. In addition, different system integrations are presented for future studies and evaluation. The results of this thesis will allow the inclusion of byproducts or waste from industries in the search spectrum for TCES and CCS materials, resulting in the acceleration of the industrial implementation of TCES, thus making TCES more sustainable and affordable from the ecological and economical viewpoint.