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Gewählte Master / Diploma Thesis:

Lorenz Untersulzner (2021): Reduction and Oxidation dynamics of a fixed bed Chemical Looping combustion reactor, with the usage of ammonia for the reduction.
Master / Diploma Thesis - Institut für Verfahrens- und Energietechnik (IVET), BOKU-Universität für Bodenkultur, pp 97. UB BOKU obvsg FullText

Data Source: ZID Abstracts
Abstract:
The project Ammonia2HeatStorage tries to combine the Chemical Looping Combustion (CLC) technology and the membrane distillation (MD) technology to find a storage medium for heat by using ammonia as fuel. With this, the supply share of sustainable energy/heat can be potentially increased. A fixed bed CLC reactor's simulation model allows giving a first impression about the reactor's functionality by loading it with ammonia. The reactor measures 3.6 cm in diameter and 30 cm in length, similar to the pilot plant's geometry at AEE Intec at Gleisdorf/Austria. The reactor uses a copper-based oxygen carrier supported by aluminum oxide. The model uses data from the literature to estimate the reaction kinetics for the solid material. The simulation allows testing with hydrogen and ammonia as fuel as well as the oxidation with air. Furthermore, two different approaches for a cyclic operation are tested. The influence of the temperature on the reaction dynamics for both fuels and the oxidation reaction is tested. The temperature was varied between 500 and 900°C. The temperature showed little influence on the temperature difference and the heat generated for reduction reactions, as well as on the operation time. Only a small increase for all named parameters was observed. The temperature showed a far more significant influence during oxidation, with a rise of the heat generated from 500°C-900°C by one third. Ammonia did show a good conversion of the OC; yielding only half the heat that hydrogen did for the same experimental setup. The results indicate that ammonia can be used as fuel in fixed-bed CLC for high-temperature heat generation. However, ammonia from VMD is a valuable chemical and can be used as fertilizer, reducing conventional production via the Haber-Bosch process, which is very energy demanding. For the cyclic operation, it can be noted that an injection of the fuel and air from opposite sides shows a better result than the injection from the same side.

Beurteilende*r: Pröll Tobias
1.Mitwirkender: Zerobin Florian

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