本研究では比較的安価な設備を用い、低温で量産性のある炭素膜を得ることが出来る溶融塩電気化学プロセスに着目し、電解条件が炭素膜に及ぼす影響、浴温が炭素膜に及ぼす影響、基材前処理における酸活性が炭素膜と基材の密着性に及ぼす影響等を明らかにしたものである。 / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

This Master Thesis consisted in realizing a tool able to design, estimate the cost and calculate annual yields of a molten salt solar power tower. Such tool was made for a company providing CSP equipment and plant solutions for engineering, engineering and procurement or also EPC of a solar power tower. The Company wishes to propose competitive plant configurations presenting a good trade-off between cost and revenues. The Company can oversee the EPC of a whole power plant or/and supply some components of the molten salt cycle and of the water/steam cycle. The tool models a large scale solar power tower with a thermal energy storage system on EBSILON®Professional 12.04, a thermodynamic software.   When launching a simulation, the tool sizes the components of the molten salt cycle (design phase) according to user’s inputs, the other components have their characteristics based on a reference project. Depending on the size of the components, the total cost is determined and the revenues over a year of operation are calculated (annual performance). When performing several simulations with different configurations, the Company can judge about the economic viability of plant configurations by comparing their LCOEs and NPVs.   The present document describes the result of the Master Thesis, that is to say the tool itself, what it contains and how it works. The methodology adopted to design the components is presented in depth, the way costs were calculated is exposed. The document explains the annual performance calculations and the simple operation strategy implemented. Finally, a technical and cost validation was carried out but it would require some further work to be complete. The design and cost calculations are performed in few seconds, the annual calculations take around 2-3h.   One main contribution of the Master Thesis is to show that designing, estimating costs and calculating annual performances is feasible in a single tool operating at a high level of detail. Using the tool during a solar power tower project could considerably facilitate the current process in place at the Company. It can also allow to compare an important number of configurations to determine a good techno-economic solution. / Denna uppsats bestod i att genomföra ett verktyg som kan utforma, beräkna kostnaden och beräkna årliga avkastningar på ett smält salt soltorn. Ett sådant verktyg gjordes för ett företag inom soltornsteknik, upphandling och konstruktion (SUK) som vill föreslå konkurrenskraftiga anläggningskonfigurationer som presenterar en bra avvägning mellan kostnad och intäkter. Företaget, samtidigt som det övervakar SUK för en hel kraftverk, levererar det också vissa komponenter i den smälta saltcykeln. Verktyget modellerar ett storskaligt soltorn med ett värmeenergilagringssystem på EBSILON®Professional 12.04, en termodynamisk programvara.   När en simulering startas, ritar verktyget komponenterna i den smälta saltcykeln (designfas) enligt användarens inmatningar, de andra komponenterna är baserade på ett referensprojekt. Beroende på komponenternas storlek bestäms den totala kostnaden och intäkterna över ett verksamhetsår beräknas (årlig prestation). När flera simuleringar görs med olika konfigurationer kan företaget bedöma sin ekonomiska lönsamhet genom att jämföra sina LCOE och NPV.   Det här dokumentet beskriver resultatet av masterprojektet, det vill säga själva verktyget, vad det innehåller och hur det fungerar. Den metod som antagits för att designa komponenterna presenteras grundligt samt hur kostnaderna beräknades. Dokumentet förklarar de årliga prestationsberäkningarna och den enkla operationsstrategin som implementerats. Slutligen genomfördes en teknisk och kostnadsvalidering, men det skulle kräva ytterligare insats för att göra arbetet fullständigt. Konstruktionen och kostnadsberäkningarna utförs på få sekunder, de årliga beräkningarna tar cirka 2-3 timmar.   Ett huvudbidrag av examensarbetet är att visa att utformning, uppskattning av kostnader och beräkning av årliga prestanda är möjlig i ett enda verktyg som arbetar på en detaljrik nivå. Att använda verktyget under ett soltornsprojekt kan betydligt underlätta den nuvarande processen på plats hos företaget. Det kan också göra det möjligt att jämföra ett viktigt antal konfigurationer för att bestämma en bra tekno-ekonomisk lösning.

The development of thermal barrier coatings (TBCs) has been undoubtedly the most critical advancement in materials technology for modern gas turbine engines. TBCs are widely used in gas turbine engines for both power-generation and propulsion applications. Metallic oxidation-resistant coatings (ORCs) are also widely employed as a stand-alone protective coating or bond coat for TBCs in many high-temperature applications. Among the widely studied durability issues in these high-temperature protective coatings, one critical challenge that received greater attention in recent years is their resistance to high-temperature degradation due to corrosive deposits arising from fuel impurities and CMAS (calcium-magnesium-alumino-silicate) sand deposits from air ingestion. The presence of vanadium, sulfur, phosphorus, sodium and calcium impurities in alternative fuels warrants a clear understanding of high-temperature materials degradation for the development of fuel-flexible gas turbine engines. Degradation due to CMAS is a critical problem for gas turbine components operating in a dust-laden environment. In this study, high-temperature degradation due to aggressive deposits such as V2O5, P2O5, Na2SO4, NaVO3, CaSO4 and a laboratory-synthesized CMAS sand for free-standing air plasma sprayed (APS) yttria stabilized zirconia (YSZ), the topcoat of the TBC system, and APS CoNiCrAlY, the bond coat of the TBC system or a stand-alone ORC, is examined. Phase transformations and microstructural development were examined by using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. This study demonstrated that the V2O5 melt degrades the APS YSZ through the formation of ZrV2O7 and YVO4 at temperatures below 747°C and above 747°C, respectively. Formation of YVO4 leads to the depletion of the Y2O3 stabilizer and the deleterious transformation of the YSZ to the monoclinic ZrO2 phase. The investigation on the YSZ degradation by Na2SO4 and a Na2SO4 + V2O5 mixture (50-50 mol. %) demonstrated that Na2SO4 itself did not degrade the YSZ, however, in the presence of V2O5, Na2SO4 formed vanadates such as NaVO3 that degraded the YSZ through YVO4 formation at temperature as low as 700°C. The APS YSZ was found to react with the P2O5 melt by forming ZrP2O7 at all temperatures. This interaction led to the depletion of ZrO2 in the YSZ (i.e., enrichment of Y2O3 in t' -YSZ) and promoted the formation of the fluorite-cubic ZrO2 phase. Above 1250°C, CMAS deposits were observed to readily infiltrate and significantly dissolve the YSZ coating via thermochemical interactions. Upon cooling, zirconia reprecipitated with a spherical morphology and a composition that depended on the local melt chemistry. The molten CMAS attack destabilized the YSZ through the detrimental phase transformation (t - > t - > f + m). Free standing APS CoNiCrAlY was also prone to degradation by corrosive molten deposits. The V2O5 melt degraded the APS CoNiCrAlY through various reactions involving acidic dissolution of the protective oxide scale, which yielded substitutional-solid solution vanadates such as (Co,Ni)3(VO4)2 and (Cr,Al)VO4. The molten P2O5, on the other hand, was found to consume the bond coat constituents significantly via reactions that formed both Ni/Co rich phosphates and Cr/Al rich phosphates. Sulfate deposits such as Na2SO4, when tested in encapsulation, damaged the CoNiCrAlY by Type I acidic fluxing hot corrosion mechanisms at 1000°C that resulted in accelerated oxidation and sulfidation. The formation of a protective continuous Al2O3 oxide scale by preoxidation treatment significantly delayed the hot corrosion of CoNiCrAlY by sulfates. However, CoNiCrAlY in both as-sprayed and preoxidized condition suffered a significant damage by CaSO4 deposits via a basic fluxing mechanism that yielded CaCrO4 and CaAl2O4. The CMAS melt also dissolved the protective Al2O3 oxide scale developed on CoNiCrAlY by forming anorthite platelets and spinel oxides. Based on the detailed investigation on degradation of the APS YSZ and CoNiCrAlY by various corrosive deposits, an experimental attempt was carried out to mitigate the melt-induced deposit attack. Experimental results from this study demonstrate, for the first time, that an oxide overlay produced by electrophoretic deposition (EPD) can effectively perform as an environmental barrier overlay for APS TBCs. The EPD protective overlay has a uniform and easily-controllable thickness, uniformly distributed closed pores and tailored chemistry. The EPD Al2O3 and MgO overlays were successful in protecting the APS YSZ TBCs against CMAS attack and hot corrosion attack (e.g., sulfate and vanadate), respectively. Furnace thermal cyclic oxidation testing of overlay-modified TBCs on bond-coated superalloy also demonstrated the good adhesive durability of the EPD Al2O3 overlay.

One of the key challenges the world will need to face during the 21st century is global warming and the consequent climate change. Its presence is indisputable, and decarbonizing the gird emerges as one of the required pathways to achieve global sustainable objectives. Solar energy power plants have the potential to revert this situation and solve the problem. One way to harness this energy is through Concentrated Solar Power plants. The major advantage and potential of this technology is its ability to integrate cost-effective Thermal Energy Storage (TES), which is key with such an inherently intermittent resource. On the other hand, the drawback is the high current Levelized Cost of Energy (LCOE). The other main way to harness that highlighted solar energy is the use of Photovoltaic panels, which have recently achieved very competitive LCOE values. On the other hand, the storage integration is still a very pricey option, normally done with Battery Energy Storage Systems (BESS). As a conclusion, a hybrid power plant combining the LCOE of the PV and the TES of the CSP emerges as the key way of achieving a very competitive solution with a big potential. This master thesis aims at exploring the possibilities of a hybrid CSP and PV power plant with a sCO2 power cycle, integrated in the primary, secondary and tertiary electricity markets. To achieve this purpose, firstly, a Python-based Energy Dispatcher was developed to control the hybrid power plant. Indeed, the Dispatcher is the tool that decides when to produce, when to store… following an optimization problem. This can be formulated mathematically, and that was done and integrated into the Python code using Pyomo, a software for optimization problems. As a result, the Dispatcher achieved an effective control of the plant, showing intelligent decisions in detailed hourly analyses. The results were very promising and included optimization functions as maximizing the profitability of the plant or the total production, among others. To proceed with the Techno-economic assessment of the hybrid plant, the electricity markets were studied. The main source of income of any power plant is normally the revenue from selling electricity to the grid, but since there are several markets, there are also other possibilities. In this thesis, it was assessed from a Techno-Economic perspective how the performance and optimal design of the plants vary when providing different services extra to selling electricity to the grid. The conclusion was that even though the Net Present Value (NPV) achieved working on the spot market was already very high, the extra value added from participating in the secondary or tertiary markets was indisputable. Indeed, the profits attained in those markets were between two and four times higher than the ones of the spot market. This is a specific case, but a trend was identified: these hybrid power plants have a huge possibility and a bright future on the service markets. As a consequence, this thesis shows the huge potential of hybrid power plants integrated in the grid participating in several markets. It also lays the foundation for future studies in other locations, under different conditions and with different technologies, among others.

Renewable energy production with wind turbines has been rising in the last 30 years and it is a crucial technology, which is necessary for the energy transition. As sustainable as the energy production of wind turbines is, the waste management of the blade material is not. Most of the blades end up on a landfill or get incinerated. There are different types of recycling methods, but the most commonly used is to shred the fibers into little pieces and reusing them for filler material in the concrete industry. This approach does not actually split up the blade material into its components but it is more of a downcycling. In this thesis, a new type of pyrolysis will be looked into, which splits up the blade material into its components namely glass fibers and plastic using molten salt. This process would make the glass fiber industry more sustainable by introducing a recycled glass fiber with minimal loss in quality. In a first step, the blade material will be examined more closely with a thermogravimetric analysis to find out what kind of plastic it is and what temperature would be necessary to pyrolyze it. This information will be used to conduct an experiment in a molten salt solution and determine the necessary reaction time and temperature. This data will be used to compare the costs of this method with shredding the material and the conventional pyrolysis. From the thermogravimetric analysis, it was possible to determine that the type of plastic used in this turbine was made out of epoxy. The maximum degredation of this material occurred at 380 ◦C. Not many experiments could be conducted in order to find the optimal conditions for the pyrolysis process due to difficulties with the furnace. Nevertheless, one sample was successfully pyrolyzed at a temperature of 400 ◦C with a residence time of 15 minutes. With the current market conditions in the recycled glass fibers industry, this product would be too expensive and the demand would be too little. However, the market is expected to grow in the next couple years due to rising interests in circular economy and governments introducing regulations. Nevertheless, it is necessary to increase the efficiency of the molten salt pyrolysis in order to be applicable to a bigger scale. More experiments should be conducted with cheaper molten salt in order to sink the costs of the process.

Rare earth and actinide metals, critical to security, medicine, and the economy, have been processed through methods such as solvent extraction and electrorefining. To minimize radiological waste and improve yield, a 'chloride volatility' process--also known as the chlorination and volatilization process (CVP)--has been proposed and demonstrated for processing rare earths. The process takes advantage of the low vapor pressure of rare earth chlorides (<700 >°C), CaCl2 was added to LaCl3 to lower the melting temperature. LaCl3 electrochemical behavior has not previously been studied in CaCl2. Cyclic voltammetry (CV) and square wave voltammetry (SWV) were applied to LaCl3 salts in CaCl2-LiCl and CaCl2 to study the metal ion behavior. Various electrode materials were compared at low CV scan rates (s-1) to determine compatibility with chlorine gas evolution. Experiments of eutectic LaCl3-CaCl2 were performed and analyzed to determine the efficacy of chlorine gas generation via electrolysis for the CVP. Through galvanostatic electrolysis, oxidation of chloride ions and subsequent chlorination of rare earth was demonstrated, with cerium chosen as the representative rare earth metal. Through a quadrupole mass spectrometer plumbed in line with the electrolytic cell, the quality of the generated gas was analyzed.

No description available.

Over the last two decades, there has been widespread international interest in the development of the molten salt reactor concept due to its passive safety, high coolant boiling temperature, low operational pressure, high thermal efficiency, and ease of breeding. Terrestrial Energy Incorporated (TEI) is developing a thermal-spectrum converter type molten salt reactor, called the Integral Molten Salt Reactor (IMSR-400) to be built by 2030. A physics experiment is needed in order to validate the theoretical predictions of the temperature reactivity coefficients of the IMSR-400. This thesis will determine the feasibility of conducting a subcritical experiment, utilizing a Deuterium-Deuterium Fusion Neutron Source (DD). / Thesis / Master of Science (MSc)

No / Rheological characterisation of hydroxyapatite -high density polyethylene (HA-HDPE) composites has been performed in terms of isothermal compressibility and wall slip. Addition of HA to the polymer melt decreases the compressibility of the melt. The unfilled HDPE was found to exhibit wall slip at shear stresses as low as 0.10 MPa. The flow curves of the composites showed three distinct regions: a gradient at low shear rates; a plateau region; and a gradient at higher shear rate. An increase in rheometer pressure seems to suppress the slip in composites. The 40 vol.-% HA-HDPE composite exhibited two critical shear stresses, one corresponding to wall slip, which occurs in the lower shear rate region of the flow curve, and the other corresponding to a plateau, which is identified with the stick-slip behaviour of unfilled HDPE reported in the literature. The plateau shear stress increased with filler volume fraction and this effect is attributed to the decreased compressibility of the melt. A good correlation with a negative correlation coefficient was found to exist between compressibility and shear stress in the plateau region. The slip observed in unfilled HDPE and at low shear rates in the 40 vol.-% HA- HDPE systems has been explained in terms of a low molecular weight polymer layer formed at the melt/wall interface. The large interfacial slip observed in the plateau region is attributed to complete disentanglement of adsorbed chains from free chains at the melt/wall interface at and beyond the plateau region.

No / Experimental observations of melt temperature profiles and melting performance of extruder screws are reported. A novel temperature sensor consisting of a grid of thermocouple junctions was used to take multiple temperature readings in real time across melt flow in a single screw extruder. Melt pressure in the die and power consumption were also monitored. Three extruder screws at a range of screw speeds were examined for a commercial grade of low density polyethylene. Results showed melt temperature fields at low throughputs to be relatively independent of screw geometry with a flat-shaped temperature profile dominated by conduction. At high throughputs, melting performance and measured temperature fields were highly dependent upon screw geometry. A barrier-flighted screw with Maddock mixer achieved significantly better melting than single flighted screws. Low temperature "shoulder" regions were observed in the temperature profiles of single-flighted screws at high throughput, due to late melting of the solid bed. Stability of the melt flow was also dependent upon screw geometry and the barrier-flighted screw achieving flow with lower variation in melt pressure and temperature. Dimensionless numbers were used to analyze the relative importance of conduction, convection, and viscous shear to the state of the melt at a range of extrusion conditions.