Repositório do LNEG
Repositório Científico do Laboratório Nacional de Energia e Geologia
Entradas recentes
Comparative Analysis of Pyrolysis and Anaerobic Digestion as End-of-Life Options for Used Cork Stoppers
Publication . Moura, Patrícia; Jesus, João; Eusebio, Ana; Costa, Paula; Marques, Susana; Oliveira, Ana Cristina; Abreu, Mariana; França, Bruna Thomazinho; Maganinho, Cristiana
ABSTRACT: The cork industry generates valuable by-products and residues with significant potential within a circular bioeconomy framework. This study evaluated the energy-driven valorization of two post-consumer cork residues—natural cork stoppers (NCS) and technical cork stoppers (TCS)—through anaerobic digestion and pyrolysis. Both NCS and TCS exhibited low moisture and ash content, a high heating value of 25.14 and 29.88 MJ/kg, respectively, a carbon content exceeding 58 wt% and low nitrogen, sulfur and chlorine concentrations. These characteristics highlight the suitability of NCS and TCS for energy recovery applications. Anaerobic digestion produced biogas containing 68.5 vol% of methane after alkaline pretreatment of TCS. However, the maximum biochemical methane potential was low, reaching only 19.5 L CH4/kg VS. The resulting digestates contained nitrogen, phosphorus and potassium at levels compatible with agricultural use. Slow pyrolysis of the cork residues resulted in high biochar yields, with NCS achieving an average yield of 64.8 wt%. Combined with carbon contents of up to 66.3 wt%, the biochars produced from NCS and TCS show strong potential for valorization as solid energy carriers, as well as for applications such as activated carbon production and soil amendment. Overall, thermochemical conversion via pyrolysis proved to be the most effective pathway for energy valorization of the tested cork residues, whereas the performance of anaerobic digestion remained limited unless more intensive pretreatment strategies were applied.
Estudos Técnicos para o Potencial Energético Offshore: Projeto LNEG EOLOS.Mar
Publication . Estanqueiro, Ana; Simões, Teresa; Couto, António; Costa, Paula Silva; Justino, Paulo Alexandre
ABSTRACT: O projeto EOLOS.Mar, desenvolvido pelo Laboratório Nacional de Energia e Geologia (LNEG) no âmbito do investimento PRR RP-C21-i07.02 – Estudos Técnicos para o Potencial Energético Offshore, constituiu uma iniciativa estruturante para apoiar o desenvolvimento da energia eólica offshore em Portugal. Ancorado nos objetivos nacionais do PNEC 2030 – Plano Nacional de Energia e Clima, o projeto teve como principal objetivo realizar a caracterização experimental dos recursos energéticos marinhos em 4 áreas prioritárias da costa continental portuguesa, áreas essas definidas no Plano de Afetação para as Energias Renováveis Offshore (PAER, versão 2023) produzindo, assim, informação técnico-científica indispensável ao planeamento e à futura instalação de centros eletroprodutores offshore. A abordagem adotada assentou na realização de campanhas experimentais concebidas segundo as melhores práticas internacionais para avaliação do recurso eólico offshore, seguindo recomendações da International Energy Agency (IEA Wind TCP), da Offshore Wind Accelerator (OWA) e das normas internacionais da International Electrotechnical Commission (IEC). Para minimizar as incertezas inerentes à caracterização do vento sobre o mar, foi implementada uma estratégia integrada de monitorização baseada na operação simultânea de sistemas LiDAR (Light Detection and Ranging) flutuantes, coadjuvados por sistemas LiDAR costeiros de referência e por mastros meteorológicos e anemométricos convencionais, permitindo combinar as vantagens das tecnologias de deteção remota com medições de referência de elevada fiabilidade. As campanhas experimentais abrangeram quatro áreas marítimas representativas das zonas definidas na versão inicial do PAER, totalizando cerca de 2452 km² de área monitorizada ao largo da costa continental portuguesa. A seleção das localizações, da instrumentação e da duração das campanhas foi cuidadosamente planeada para assegurar a obtenção de dados representativos do recurso eólico offshore e, simultaneamente, caracterizar parâmetros oceanográficos relevantes para o desenvolvimento, operação e manutenção de futuras centrais eólicas, incluindo ondulação, correntes marítimas e variáveis meteorológicas complementares. O projeto envolveu a instalação e operação de quatro sistemas LiDAR flutuantes, dois sistemas LiDAR costeiros e duas estações meteorológicas de referência, constituindo uma infraestrutura experimental sem precedentes em Portugal, para caracterização integrada do ambiente offshore. Os sistemas permitiram monitorizar perfis verticais do vento até altitudes compatíveis com os rotores das atuais turbinas eólicas de grande potência, bem como recolher informação sobre temperatura, humidade, pressão atmosférica, estado do mar e correntes marítimas, disponibilizando um conjunto alargado de variáveis essenciais à avaliação técnica e económica de futuras centrais renováveis offshore.
Marine biomineralization as MICI process. A basis for new anticorrosion surface treatments [Comunicação oral]
Publication . Marques, Maria João; Zanna, Sandrine; Marcus, Philippe; Basseguy, Regine
ABSTRACT: The development of sustainable corrosion protection strategies is a major challenge in materials engineering, particularly for metallic structures exposed to marine environments. While microorganisms are traditionally regarded as contributors to corrosion processes, their potential role in Microbiologically Influenced Corrosion Inhibition (MICI) remains largely underexplored. The objective of this presentation is to highlight the potential of MICI mechanisms as a novel pathway for corrosion protection solutions, with particular emphasis on biomineralization processes.
Atmospheric Corrosion Resistance of Marine Biomineralized Layers on Aluminium – Magnesium Alloy [Comunicação oral]
Publication . Marques, Maria João; Mercier, Dimitri; Seyeux, Antoine; Zanna, Sandrine; Marcus, Philippe; Basseguy, Regine
ABSTRACT: Developing solutions to improve the durability of materials remains a key challenge in surface science, especially for aluminium and aluminium alloys. In this context, marine biomineralization processes have been shown to offer potential as a novel approach for developing more sustainable corrosion protection solutions [1,2]. These solutions are based on the spontaneous formation of biomineralized layers, which exhibit a hybrid inorganic-organic nature and are capable of mitigating the corrosion of aluminium alloys, specifically Al-Mg alloys [3,4]. The present study investigates the corrosion resistance, under natural atmospheric exposure conditions, of marine biomineralized layers formed on Al-Mg surfaces. More specifically, the evaluation tests were carried out at an outdoor marine/industrial test site (Sines, Portugal). Morphological and chemical characterizations were performed before and after the exposure, mainly by SEM/EDX and XPS, enabling the assessment of the Al-Mg surface modifications and the impact of the natural atmospheric corrosion test on the biomineralized layer.
Metals recovery from end-of-life Li-ion batteries by physical processing and hydrometallurgical treatment [Poster]
Publication . Moço, Duarte; Morais, F.; Almeida, Joana; Neiva Correia, Maria Joana; Margarido, Fernanda; Pedrosa, Fátima; Plancha, Maria João; Gonçalves, Ana; Nogueira, Carlos
ABSTRACT: The growing demand for lithium-ion batteries (LIB) for electric mobility and energy storage applications has created enormous pressure on the metals market, not only for lithium (Li) but also for other critical metals such as nickel (Ni), cobalt (Co) and manganese (Mn). Beyond the need for primary extraction of mineral resources, which is essential for an initial phase of significant growth in demand, recycling will quickly play a fundamental role in the availability of these raw materials. Recycling also allows a valuable contribution to the management of end-of-life batteries (Dobó et al., 2023). Recycling of LIB is predominantly conducted through hydrometallurgical methods, involving both physical/mechanical processes (such as electrode fraction concentration) and chemical processes (including leaching, separation and recovery).
The physical operations include safe discharge and dismantling, followed by shredding and separation of fractions (Sommerville et al., 2020). In hydrometallurgical processing, metals are leached and recovered from aqueous solutions using different methods (Bae and Kim, 2021). This work presents findings from research on the physical and chemical treatment of end-of-life LIB (Ni-Co-Mn or NCM type), with an emphasis on the obtained recoveries and yields.