• European Marine Science
• 2018-2022close
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The growing population requires a lot of food in order to sustain itself. Therefore, also, more fish need to be caught and farmed. Since a large amount of fish captured cannot be used commercially, it is usually thrown away, which in turn can be hazardous to the environment not to mention sea birds. By catch is also caught when fishing. A circular approach to this fish waste means seeing this waste as something that should be used instead of being thrown away. Usually fish waste if not discharged overboard, is converted into fish meal or fish oil. It is often costly and time-consuming. The heterogeneous nature of fish waste is an added challenge because finding solutions that work all the time with all types of fish waste is not possible. The lab-scale applications mentioned in this thesis include, but are not limited to, turning fish waste into fertilizer, feed, nutrients, peptides, enzymes, hydrolysates, biomaterials, wastewater treatment products, and biofuels. This thesis was a literature review, and no lab work was donewhen making it.Fertilizer and feed are relatively straight-forward to do, but they require more time to be aged than their commercial counterparts. Nutrients, peptides, hydrolysates, and enzymes can also be extracted from the fish waste; however, in the case of mincing the fish waste it can only replace part of the fish meat. Peptides showed interesting properties but required more research to be identified precisely. Hydroly-sates could be used for capturing moisture in the food industry, but their inner bitterness needs to be masked beforehand. Enzymes can be extracted, but their performance varies; an enzyme for dehairing leather works great, but an enzyme to make cheese creates a cheese that cannot hold moisture inside it. Fish waste can also be added into packaging materials, where the biodegradability increase, but this comes at the cost of weaker strength and an inability to hold moisture inside the package. Their properties can be improved by adding additional substances into the material. Fish waste can also be used to manufacture sorbents for treating wastewater and in the articles they could remove, for example, azodyes and lead. Fish waste can also be converted into biofuels. However, they increase some emissions, while simultaneously reducing others and they cannot be stored as long as conventionally made diesel. Fish waste has many potential applications, but their large-scale implementation requires massive investments in a circular economy.

Diese Bachelorarbeit beschäftigt sich mit der Entwicklung einer solarbetriebenen Kammertrockenanlage für Fisch. Das neue Design wurde auf Basis eines bereits getesteten Prototyps entwickelt. Zur Verbesserung der Luftströmung wurden die Trocknungsebenen versetzt zueinander angeordnet, wodurch frische Luft jede Ebene zur selben Zeit durchströmt. Eine CFD Analyse ergab jedoch Probleme bei der Luftströmung in den unteren Ebenen. Die Luft strömte nicht einheitlich nach oben, sondern sich von der Mitte zu den Seiten verteilend. Sie war nicht einheitlich über den Querschnitt verteilt. Dadurch ergab sich das Problem, dass die Luft in den unteren Ebenen an den Seiten einströmte, wodurch sich innerhalb einer Ebene Strudel ausbildeten. Die Luft strömte also nicht wie vorgesehen von vorne nach hinten, sondern in der Mitte der Ebene von hinten nach vorne. Um eine ungleichmäßige Trocknung des Fisches hierdurch zu verhindern, wurde das Design erneut optimiert. Im unteren Teil der Anlage, im Bereich des Lufteinlasses, wurde ein Aufprallblech installiert, welches für eine frühere Verteilung der Luft sorgt. Darüber hinaus wird nun durch zusätzliche Bleche, die als Strombrecher fungieren, in den Schubladen das Ausbilden von Wirbeln verhindert. Durch diese Maßnahmen konnten die Probleme gelöst werden und eine gleichmäßigere Trocknung des Fisches ist möglich. In this final thesis, a drying chamber has been developed, on the basis of a previous prototype. A new design has been drawn in Inventor 2018 and has been tested then in Autodesk CFD 2018, to figure out air flow problems beforehand. Additional, first calculation has been done, to examine the running conditions. To improve the air flow, the drawers have been staggered in reverse order. The CFD Analysis has shown, that there were still air flow problems in the lower levels of the chamber. The air did not flow equally up but had to distribute during the up flow from the middle to the edges. This led to the creation of a vortex in the lower levels and, therefore, to a flow of the air in the wrong direction, from the backside of the chamber to its front. To prevent an unequal drying by this, changes in the design has been done. After adding a deflection plate in the ground of the device in front of the inlet and of plates to the drawers, the problems have been solved. The calculations have shown, that the drying will need 6 ℎ, while the air flow rate at the inlet is about 0,1. The next step will be to build a new prototype and to do further testing. Especially the air flow rate and the drying time has to be tested, because the calculations are based on assumptions.

In this thesis, the creation of a Python based interactive map of the world’s wave energy resources is explained and presented. The application will be used by Wello Oy to generate values needed in wave energy production in various locations across the world, and to calculate the theoretical power of Wello’s Penguin wave energy converter. The application is planned to be used as an easy-to-use tool to quickly and effectively measure the power output of the Penguin wave energy converter at any given site in the world. The application allows tailored results that are calculated by using values obtained from each potential wave energy site. The results show the end user the wave energy at the site, and the optimal dimensions of the wave energy converter for maximal power production and maximal return of investment. The fundamentals of wave energy and wave energy converters are discussed, as well as the methodology for calculating the theoretical power output of waves and calculating the levelized cost of energy at each of these sites. All this is done in hope of making the process of finding potential wave energy projects more efficient and effective, and thus providing a clean, renewable and continuous energy source to the world.