44 documents found, page 1 of 5
Thermal Shock Resistance of Commercial Oxide-Bonded Silicon Carbide Reticulated...
Oliveira, Fernando Almeida Costa; Galindo, José; Rodriguez, Jose; Cañadas, Inmaculada; Fernandes, Jorge CruzABSTRACT: Volumetric ceramic receivers can be regarded as a promising technology to heat air above 1000 ◦C for solar thermal electricity production. In this study, the thermal shock behavior of commercial 10 ppi (A) and 20 ppi (B) oxide-bonded silicon carbide (ob-SiC) reticulated porous ceramic (RPC) foams was evaluated using the SF60 solar furnace at Plataforma Solar de Almería. The foams were subjected to wel...
Manufacturing and Thermal Shock Resistance of 3D-Printed Porous Black Zirconia ...
Oliveira, Fernando Almeida Costa; Sardinha, Manuel; Galindo, José; Rodríguez, José; Cañadas, Inmaculada; Leite, Marco; Fernandes, Jorge CruzABSTRACT: A novel approach for manufacturing porous materials, foreseen as solar receivers for concentrated sun radiation, used in the power tower technology is presented. In such applications, materials are subjected to steep thermal gradients and thousands of cycles. Yet, materials consisting of honeycombs and ceramic foams showed insufficient thermal performance. By using the fused filament fabrication proce...
Thermal decomposition of δ-MoN and ε-Fe2N synthesized under concentrated solar ...
Cañadas, Inmaculada; Oliveira, Fernando Almeida Costa; Rodriguez, Jose; Shohoji, NobumitsuABSTRACT: Decomposition temperatures of δ-MoN and ε-Fe2N synthesized with flowing NH3 gas under concentrated solar radiation heating were evaluated by Differential Scanning Calorimetry (DSC) in Argon (Ar) gas environment. The measured decomposition temperature of δ-MoN and ε-Fe2N were dependent on the solar synthesis conditions, particularly either NH3 or N2 gas flow rate at temperature. Sample containing δ-MoN...
A New Insight into the Role of Silicate-Type Binders on the Crushing Strength o...
Oliveira, Fernando Almeida Costa; Pommier, Stéphane; Fernandes, Jorge Cruz; Dias, DiamantinoABSTRACT: Semi-closed cell macroporous alumina foams with relative densities ranging from 0.26 to 0.35 have been produced by the well-established replication method based on the coating of a polyurethane (PU) template foam by a ceramic slurry, followed by burnout of the PU template, and sintering of the ceramic skeleton. Collapse of the three-dimensional structure upon the volatilisation of the PU sponge can on...
Slow pyrolysis of cork granules under nitrogen atmosphere: by-products characte...
Costa, Paula; Barreiros, M. Alexandra; Mouquinho, Ana; Silva, P. Oliveira e; Paradela, Filipe; Oliveira, Fernando Almeida CostaABSTRACT: Cork granules (Quercus suber L.) were slowly pyrolyzed at temperatures between 400-700 degrees C and under N-2 flow. While preserving its structure, some cells of the cork biochar became interconnected, allowing such carbon residue to be used as templates for manufacturing ceria redox materials. The pyrolytic char morphology was similar to that of the natural precursor. The produced cork biochar belon...
Synthesis of Non-Cubic Nitride Phases of Va-Group Metals (V, Nb, and Ta) from M...
Shohoji, Nobumitsu; Oliveira, Fernando Almeida Costa; Galindo, José; Rodriguez, Jose; Cañadas, Inmaculada; Fernandes, Jorge Cruz; Rosa, Luís GuerraABSTRACT: Using a high-flux solar furnace, loosely compacted powders of Va-group transition metal (V, Nb, and Ta) were reacted with stream of NH3 gas (uncracked NH3 gas) being heated by concentrated solar beam to a temperature (T) range between 600 and 1000 degrees C. From V, sub-nitride V2N (gamma phase) and hypo-stoichiometric mono-nitride VN possessing fcc (face-centered cubic) crystal lattice structure (del...
Novos avanços no processo de fabrico de espumas de céria para produção de hidro...
Oliveira, Fernando Almeida Costa; Mouquinho, Ana; Barreiros, M. AlexandraRESUMO: Este trabalho reporta um processo alternativo ao utilizado anteriormente para a produção de espumas de céria, pelo método de replicação de esponjas polimérica patenteado, em 1963, por Schwartzwalder e Somers. As referidas espumas destinam-se a servir de catalisadores à reação de separação da água pela via termoquímica solar. Esta via envolve um ciclo redox, em que a redução endotérmica da céria ocorre a...
High performance cork-templated ceria for solar thermochemical hydrogen product...
Oliveira, Fernando Almeida Costa; Barreiros, M. Alexandra; Haeussler, Anita; Caetano, Ana P. F.; Mouquinho, Ana; Silva, P. Oliveira e; Novais, Rui M.ABSTRACT: Water splitting by solar energy-driven two-step thermochemical cycles is a promising approach for large-scale production of renewable fuels (e.g. hydrogen). The key challenge is developing materials capable of withstanding the harsh environmental conditions and to ensure high reliability in use, particularly in terms of redox kinetics and better activity at low operation temperatures. In this work, we...
Solar redox cycling of ceria structures based on fiber boards, foams, and biomi...
Haeussler, Anita; Abanades, Stéphane; Oliveira, Fernando Almeida Costa; Barreiros, M. Alexandra; Caetano, Ana P. F.; Novais, Rui M.; Pullar, Robert C.ABSTRACT: Solar thermochemical conversion of H2O and captured CO2 is considered for the production of high-value solar fuels and CO2 valorization, using nonstoichiometric oxygen-exchange redox materials. This work aims to compare the thermochemical cycle performance of different ceria structures, including biomimetic cork-templated ceria (CTCe), ceria foams (CeF), and ceria bulk fiber boards (CeFB), to study th...
A review of solar thermochemical CO2 splitting using ceria-based ceramics with ...
Pullar, Robert C.; Novais, Rui M.; Caetano, Ana P. F.; Barreiros, M. Alexandra; Abanades, Stéphane; Oliveira, Fernando Almeida CostaABSTRACT: This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from carbon dioxide (CO2). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light ...