ME - Resumos em livros de actas
Permanent URI for this collection
Browse
Recent Submissions
- La biominéralisation comme bioinspiration pour le développement de solutions anti-corrosion [Resumo]Publication . BASSEGUY, Regine; Marques, Maria JoãoRÉSUMÉ: Dans le domaine de la corrosion, la nature se révèle être une source d’inspiration pour développer de nouveaux concepts de protection verts. En effet, il est largement reconnu que les micro-organismes sont capables non seulement d’accélérer la orrosion mais ils peuvent également l'inhiber et/ou protéger les matériaux qu’ils colonisent [1]. Ce constat a ainsi conduit à proposer des stratégies à base microbienne pour l'inhibition de la corrosion des métaux. En particulier, le processus de biominéralisation à la surface des matériaux, tels que les pierres, le béton et divers métaux, a récemment été considéré comme une nouvelle approche respectueuse de l'environnement pour produire des couches protectrices [2-3]. Jusqu’à peu, la majorité des publications concernaient les aciers, matériaux historiquement utilisés dans les infrastructures. Au cours des dernières années, de nouveaux matériaux tels que les alliages d'aluminium, sont apparus sur le marché comme des alternatives possibles. Dans le cas spécifique de l'alliage Al-Mg, souvent utilisé dans les applications marines, peu d'études ont évalué l'influence de la biominéralisation sur la corrosion [4-6]. L'objectif de cette présentation est de montrer, à travers deux études de cas, comment la précipitation minérale influencée par l’activité microbienne sur les matériaux métalliques peut être envisagée comme une nouvelle approche pour le développement de solutions anti-corrosion.
- Enhancing Corrosion Resistance of Al-Mg Alloys through Biomineralization [Resumo]Publication . Marques, Maria João; Fori, Benoit; Mercier, Dimitri; Seyeux, Antoine; Zanna, Sandrine; Marcus, Philippe; BASSEGUY, RegineABSTRACT: In recent decades, new emerging microbiological technologies have been studied, based on the recognition that microorganisms can inhibit corrosion by different mechanisms, the so-called MICI (microbiologically influenced corrosion inhibition), opening up different lines of research. In this context, biomineralization has been attracting the attention of researchers, with an increasing number of studies showing that different types of mineralized layers formed on metal surfaces can reduce the risk of corrosion.
- Influência da metodologia experimental de remoção de óxidos na avaliação da velocidade de corrosão de aços inoxidáveis em contacto com sais fundidos [Resumo]Publication . Pedrosa, Fátima; Cunha Diamantino, Teresa; Gil, Mafalda; Paiva Luís, Teresa; Figueira Vasques, IsabelRESUMO: Um dos pontos fulcrais na utilização de sais fundidos como fluidos de armazenamento de energia térmica nas tecnologias de concentração de energia solar é a sua compatibilidade com os materiais estruturais metálicos. A corrosão dos materiais metálicos, tanto ao nível dos tanques de armazenamento de energia térmica, como ao nível das tubagens onde circulam estes fluídos, é um dos grandes desafios destas centrais, principalmente pelos custos envolvidos na utilização de materiais resistentes à corrosão e pelos riscos de funcionamento das centrais devido aos entupimentos provocados pelos óxidos formados no processo corrosivo ao longo do tempo. Assim, nos últimos anos têm-se realizado muitos estudos de avaliação de velocidades e dos mecanismos de corrosão- de várias ligas metálicas em contacto com sais fundidos a altas temperaturas [1,2], que demonstram uma enorme disparidade de resultados publicados devido às diferentes metodologias experimentais e aos diferentes tempos de ensaio testados a nível laboratorial. Com este trabalho, pretende-se esclarecer a influência que a metodologia experimental tem no cálculo da velocidade de corrosão e qual é que deve ser seguida para obter resultados fidedignos que possam contribuir para uma adequada seleção de materiais aquando da construção e manutenção de uma central de concentração solar.
- Methodologies for assessing corrosion under dynamic conditions with molten salts in CSP/CST applications [Resumo]Publication . Cunha Diamantino, Teresa; Pedrosa, Fátima; Paiva Luís, Teresa; Figueira Vasques, Isabel; Gil, Mafalda; Navas, M.; Veca, E.ABSTRACT: Renewable energy implementation represents a key point in reversing global warming and climate change. In recent years, there has been an investment in Concentrated Solar Power (CSP) with Energy Storage (TES). Solar Salt is the most energy storage fluid optimized with a melting point of 223 °C and thermally stable up to about 550 °C. One of the most relevant problems in the use of fluids as thermal energy storage is their compatibility with construction materials (pipes, valves and tanks). This fact, combined with high temperatures (300-550 °C) makes the materials more susceptible to corrosion. Static immersion experiments are suited to screen and compare different candidate materials for molten salt applications (Fernández et al., 2019; Gomes et al. 2019), but corrosion rates derived from these experiments might differ significantly from the rates experienced in a real operating environment of a solar plant (Florian et al. 2021). There are currently no specific procedures for evaluating corrosion in molten salts under dynamic conditions, so it is important to develop more practical application conditions to validate methodologies and facilities. The main purpose of this work is to identify the suitable procedures to make a reproducible experimental dynamic corrosion test using an experimental set-up that can vary the velocity of molten salts over a wide range.
- Corrosão dos aços AISI 316L e AISI 430 em contacto com sais fundidos de carbonatos para armazenamento de energia térmica [Comunicação oral]Publication . Gil, Mafalda; Pedrosa, Fátima; Paiva Luís, Teresa; Figueira Vasques, Isabel; Cunha Diamantino, TeresaRESUMO: Os desafios da transição energética e a tendência crescente da eletrificação da economia implicam uma clara aposta no aumento da utilização de energias renováveis. Nesse sentido, os sistemas de concentração de energia solar (CSP) ganharam considerável relevância na conversão de energia solar térmica em energia elétrica [1]. Com o crescente desenvolvimento e implementação destas tecnologias que utilizam fluidos de transferência de calor (misturas de sais fundidos) para armazenar energia térmica, tem-se revelado cada vez mais premente estudar a durabilidade, a corrosão e a compatibilidade dos materiais estruturais em contacto com estes fluidos, quando submetidos a altas temperaturas [2]. O presente trabalho tem como objetivo estudar as velocidades e os mecanismos de corrosão de dois aços inoxidáveis, o austenítico AISI 316L e o ferrítico AISI 430, em contacto com uma mistura eutéctica de sal fundido de carbonatos de lítio, sódio e potássio, em ensaios de longa duração a 650 °C. A seleção destes dois aços inoxidáveis teve por base as suas diferenças, tanto nas características intrínsecas, como no custo associado a cada um deles. A avaliação da velocidade de corrosão foi efetuada por gravimetria através da metodologia descrita na ISO 17245:2015 [3]. Para ambos os aços, a evolução da velocidade segue uma cinética parabólica apresentando o AISI 430 uma velocidade superior.
- Enhancing Conductivity in PEM Chitosan Membranes through Bisphosphonate Graphene Oxide [Resumo]Publication . Naffati, Naima; Teixeira, Fatima; Teixeira, António P. S.; Rangel, C. M.
- The corrosion behavior of aluminium-magnesium alloy in natural seawater: effects of the biological activity [Resumo]Publication . Marques, Maria João; Benedetti, A.; Castelli, F.; Delucchi, Marina; Faimali, Marco; Delsante, S.; Valenza, F.; Garaventa, F.; Pavanello, G.; Losurdo, M.; Basseguy, RegineABSTRACT: Concerning the corrosion in seawater environments, microorganisms can cause corrosion (Microbiologically Influenced Corrosion - MIC) [1], but also inhibit it or protect against it, a process known as MIC Inhibition (MICI) [2-3]. Corrosion studies of Al-Mg alloys of the 5XXX series, widely used in the shipbuilding industry, requires wider comprehension regarding the impact of the microbial activity [4-7]. Recent studies indicate that the biological activity tends to mitigate the Al alloy corrosion processes [8-11]. The objective of the present study is to assess the influence of natural seawater and the related biological activity on the resistance of the AA5083 Al-Mg alloy by the means of immersion experiments in natural (biotic) vs control (abiotic) seawater. Ennoblement of the open circuit potential (OCP) on Stainless steel (SS) probes was used to monitor the biofilm growth [12].
- Chitosan doped membranes for electrochemical devices [Resumo]Publication . Naffati, Naima; Teixeira, Fatima; Teixeira, António P. S.; Rangel, C. M.ABSTRACT: The development of new proton exchange membrane (PEM) for electrochemical devices, such as fuel cells and electrolyzers, have attracted researcher’s attention in the pursuit for more sustainable and cost-effective technologies for clean energy production, being extensive those for CO2 reduction and conversion1,2. To this end, in the present work, new modified chitosan (CS) membranes doped with ionic liquids (ILs) were developed to perform as PEM at those electrochemical devices, as an alternative to widely used commercial Nafion, with several advantages such as wider availability, lower cost, biodegradability and thermal stability. These modified membranes for use in electrochemical devices are expected to show suitably enhanced ion conductivity and also improved mechanical strength associated to a decrease in water uptake.
- The H2Excellence Project: Fuel Cells and Green Hydrogen Centers of Vocational Excellence towards affordable, secure, and sustainable energy for Europe [Resumo]Publication . Gano, António; Pinto, P.J.R.; Esteves, M. Alexandra; Rangel, C. M.ABSTRACT: The demand for green hydrogen (H2) and related technologies is expected to increase in the coming years mainly framed by drivers such as climate change and energy security of supply amid the European and global energy crises. REpowerEU Plan called for an intensification of hydrogen delivery targets, that will bring large-scale adoption of hydrogen production and applications in various sectors, stressing the need for a skilled workforce in the emergent hydrogen markets. To that end, the Erasmus+ European H2Excellence transnational project[2] has gathered 24 partners across the EU, to establish a Platform of Vocational Excellence in the field of fuel cells and green hydrogen technologies, with an educational and training offer that will tackle identified skill gaps and implement life-long learning opportunities. The project aims to become a benchmark in training and knowledge transfer, contributing to the integration of quality employment into green hydrogen local innovative systems approaching the entire hydrogen value chain.
- Tuning cathode porosity for electrochemical reduction of CO2 at high pressure [Resumo]Publication . Messias, Sofia; Fialho, Maria T.; Paninho, A. B.; Nunes, A. V. M.; Branco, Luis C; Nunes, D.; Martins, Rodrigo; Mendes, Manuel Joao; Rangel, C. M.; Machado, AnaABSTRACT: The development of active and stable catalytic cathodes is critical for advancing electrochemical carbon dioxide reduction into fuels and chemicals from Lab to market. This is a technology with a high potential to contribute to combat climate changes by using captured CO2, water and renewable energy [1]. The use of pressures higher than atmospheric pressure to carry out the co-electrolysis of CO2 and water has been recognized as an important process intensification parameter to increase productivities and energy efficiency [2]. Ongoing work addresses the preparation of aerogels by the sol gel method and impregnation with zinc and copper metallic particles to be used as cathodes for the co-electrolysis of CO2 and water to produce syngas at temperatures near room temperature and high-pressure. Ionic liquid-based electrolytes are used to increase CO2 concentration at the surface of the electrode and consequently productivities, as some ionic liquid families are known to solubilize high amounts of CO2. Aerogels have been investigated for many different applications including as catalyst supports, due to their high surface area, stability in gaseous or liquid phases, and efficient transport through large meso and macropores. The present work reports a strategy to tune the pore sizes of the catalytic electrodes by the use of reticulating agents and supercritical CO2 drying. Productivities and faradaic efficiencies of the porous materials with the different reticulating agents are compared and interpreted in respect to their surface characterization e.g. BET surface areas and morphologies determined by SEM. The potential of new aerogel-based catalytic cathodes on the efficiency of the electrochemical CO2 reduction will be discussed and its impact in fostering supercritical fluids technology through its use in processes for the mitigation of climate changes.