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- PostFörutsättningar för en skridskobana i centrala Göteborg med fokus på innovativ och miljöanpassad energiförsörjning(2024) Calisir, Theresa; Karlsson, Elin; Chalmers tekniska högskola / Institutionen för kemi och kemiteknik; Chalmers University of Technology / Department of Chemistry and Chemical Engineering; Knutsson, PavletaAs the importance of sustainability continues to increase, the need to create solutions that fits the SDG (sustainable development goal) intensifies. The purpose of the study, given from Göteborg Energi and Göteborg & Co, is to investigate the conditions for an open ice rink in central Gothenburg with a focus on innovative and environmentally friendly energy supplies. But above all, exploring different cooling systems taking into account different sustainability aspects. The goal was to gather information rather than to reach a decision on technical options or costs, due to a non-specified budget. Through literature studies and market research, details on different cooling technologies and their potential sustainability benefits and flaws were gathered. Interviews with experts within the industry complemented the records. Since the facility strives to remain in use throughout the whole year, the research indicated that hybrid cooling systems were the most optimal alternative. The cooling systems considered were a compressor cooling system and an absorption refrigerator, the motive being to utilize district heating in the form of waste heat from local industries. The facility requires a cooling effect of approximately 2,15 MW acknowledging only the outside temperature differences. A compressor cooling system is generally the most effective and reliable whilst an absorption refrigerator commonly is more sustainable but at a higher operating cost. To fully estimate the effectiveness, costs and principles of the entire system, further research with a more defined budget is necessary. The collected information provides a base for decision making and continuous future studies.
- PostA Corrosion Study on a Novel FeCrAl Alloy for Water Wall Applications in Waste-Fired Boilers(2024) Rödbro, Joachim; Chalmers tekniska högskola / Institutionen för kemi och kemiteknik; Chalmers University of Technology / Department of Chemistry and Chemical Engineering; Liske, Jesper; Lindmark, HampusToday, as society faces greater challenges regarding waste handling, the European commission have putting out directives for waste handling called “waste hierarchy”. This includes converting waste to energy. There are several technologies available of which one is the so called CFB boiler, Circulating Fluidized Bed Boiler. In this boiler the waste fuel is combusted and the heat in the flue gas is used to heat water into steam inside heat exchangers. The steam can generate electricity via a steam turbine and the heat can be used in a district heating net. The heat exchangers, e.g., superheater tubes and water walls, inside the boiler is made of metallic components. One problem a CFB boiler is facing is that the water wall heat exchangers get exposed to both heavy metals and chlorine originating from the waste. This accelerates the corrosion rate of the water wall materials. The material is usually of low-alloyed steel and a method for increasing the corrosion resistance is to put a layer of Ni-based alloy on top of the material, a so called coating. However, because of the high cost of the Ni-based coating other cheaper materials are currently under consideration. One of these is Kanthal EF101. The aim for thesis is to evaluate the corrosion rate for Kanthal EF101 when exposed to two heavy metal compounds, PbO or PbCl2 and compare it with a Ni-based alloy (Alloy625) and low-alloyed steel (T22). For this, multiple factors must be considered for example thermodynamics, kinetics, the principles of oxide formation and influence of PbO and PbCl2. The experiments in this project were divided into three steps; sample preparation, exposure and analysis. All exposures were performed with a laboratory environment simulating the water-wall in a waste fired boiler and lasted for 168 hours. The analysis used SEM and EDX instruments to create backscattered images for classification of elements on the sample and investigate the oxide growth. The results showed that EF101 has similar good protection properties as the Ni-based alloy Alloy625 and much greater protection than the low-alloyed steel T22. The presence of chlorine increased the corrosion rate of the samples, as the samples exposed to PbCl2 was severely more corroded than the corresponding samples exposed to PbO.
- PostKemisk modifiering av cellulosa med anhydrider och imidazol(2024) Daniel, Marina Tesfai; Chalmers tekniska högskola / Institutionen för kemi och kemiteknik; Chalmers University of Technology / Department of Chemistry and Chemical Engineering; Westman, Gunnar; Feldhusen, Jelka
- PostCompound Identity Verification using Collision Cross Section(2024) Saarenpää, Jennifer; Chalmers tekniska högskola / Institutionen för kemi och kemiteknik; Chalmers University of Technology / Department of Chemistry and Chemical Engineering; Malmberg, Per; Leek, Tomas
- PostAnalys av använt lösningsmedel för återanvändning med GC-FID(2024) Grundberg, Ida; Svanberg, Hannah; Chalmers tekniska högskola / Institutionen för kemi och kemiteknik; Chalmers University of Technology / Department of Chemistry and Chemical Engineering; Malmberg, Per; Åkesson, Christian