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Percorrer CIMO por Objetivos de Desenvolvimento Sustentável (ODS) "07:Energias Renováveis e Acessíveis"
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- Assessment of Agri-Solar Roof Systems: Exploring Multifunctional ApplicationsPublication . Costa, Isabella; Geraldes, Ana Maria; Calheiros, CristinaIn the current context, issues related to urban well-being and the sustainability of cities can be addressed through rooftop gardening [1] [2]. This concept reflects the growing need for sustainable urban solutions, which has driven the transformation of underutilized spaces, such as urban rooftops, into productive areas. However, challenges such as lack of technical knowledge, insufficient government support, and lack of leisure time hinder adoption [3]. The combination of agriculture and photovoltaic panels (Agri-Solar Roof Systems) emerges as an innovative strategy to optimize these spaces, allowing for simultaneous food and clean energy production. This approach promotes carbon neutrality, food security, energy efficiency, and climate resilience. However, effective implementation requires evaluating economic and socio-environmental impacts. This study aims to fill this gap by evaluating Agri-Solar Roof Systems in Portugal, focusing on exploring their multifunctional applications and benefits. Methods: The study adopts a systematic literature review to consolidate existing knowledge on Agri-Solar Roof Systems. A detailed analysis will identify technical, socio-environmental, and economic challenges and opportunities associated with these systems. In addition, surveys will be conducted with stakeholders to understand the acceptability and key factors influencing adoption in Portugal. Results: The results are expected to include technical guidelines for implementing Agri-Solar Roof Systems in Portugal and a case study demonstrating practical applicability and potential impacts. Conclusions: The integration of Agri-Solar systems represents a promising solution for urban sustainability, maximizing productivity in underutilized urban spaces through the synergy between agriculture and renewable energy. The results of this study will provide insights for policymakers, businesses, and other stakeholders, contributing to the advancement of public policies and innovative practices for more resilient and sustainable cities.
- Avaliação de sistemas de cobertura agrivoltaica: Explorando aplicações multifuncionaisPublication . Costa, Isabella; Geraldes, Ana Maria; Calheiros, CristinaAs soluções baseadas na natureza (SBN) desempenham um papel importante na resiliência das cidades, proporcionando simultaneamente benefícios ambientais, sociais e económicos. As coberturas verdes são um exemplo de SBN, que contribuem para a resiliência urbana, providenciando vários serviços ecossistémicos como gestão de águas, biodiversidade, eficiência energética, regulação da temperatura, redução do ruído e integração estética e recreativa. Além desses benefícios, o seu uso pode ser otimizado para atender a outras necessidades.Os Sistemas de Cobertura Agrivoltaica surgem como uma alternativa que integra a produção agrícola e a geração de energia solar fotovoltaica, permitindo a produção simultânea de alimentos e energia limpa, enquanto mantém os múltiplos serviços ecossistémicos proporcionados pelas coberturas verdes. Essa solução impulsiona a neutralidade carbónica, fortalece a segurança alimentar e aumenta a adaptação climática perante eventos extremos.Este estudo pretende avaliar os Sistemas de Cobertura Agrivoltaica em Portugal e explorar as suas aplicações e benefícios multifuncionais.
- Biodiesel production by transesterification using choline hydroxide as catalystPublication . Brito, Paulo; Lima, Renata; Queiroz, Ana; Ribeiro, António E.Biodiesel is a mixture of fatty acid methyl esters (FAMEs) and is a biodegradable and renewable fuel, produced from fat sources mainly composed of triglycerides. The use of ionic liquids (ILs) in biodiesel catalytic production has been studied mainly in the ecological field, as it allows a high recycling efficiency. Choline (2-hydroxyethyl trimethylammonium)-based ILs have received attention due to their biocompatibility characteristics and potential for various industrial applications. Specifically, choline hydroxide (ChOH) represents a promising option. This work's objective is the optimization of the methyl transesterification reaction conditions using commercial and waste sunflower oil (WSO) as raw material and ChOH as a catalyst, assessing the possibility of recovering the catalyst between reaction cycles. Therefore, biodiesel production was carried out on heating plates with temperature control and with magnetic stirring, using methanol reflux. After phase separation, centrifugation was used to enhance biodiesel recovery. Reaction conversion was assessed by acidity drop determination, and the biodiesel FAME content was determined by GC-FID, through a procedure in accordance with EN 14103, using methyl heptadecanoate as the internal standard. IL recovery was carried out by solvent extraction with water-based binary systems, followed by an FTIR analysis of both phases for ChOH detection, and a comparison with initial IL samples. Optimal conversions, determined by acid value (AV) reduction or by biodiesel FAME mass content, were obtained using a 4%wt. catalyst load, oil/methanol molar ratio of 1:8, duration of 1 h, and temperature of 65 °C. The products’ AV for WSO showed a significant reduction relating to the raw material AV (6.14 mgKOH/g). For the reactions with commercial sunflower oil (AV close to 0.20 mgKOH/g), the biodiesel phase AV remained low. ChOH recovery, performed with n-butanol/water and ethyl acetate/water systems, proved to be inefficient under the conditions tested. FTIR analysis showed the presence of ChOH in both liquid–liquid extraction phases.
- Comprehensive assessment of PM10 from home heating using different appliances and biomass fuels: Chemical composition, oxidative potential, and ecotoxicityPublication . Cipoli, Yago Alonso; Vicente, Estela D.; Charres, Isabella; Evtyugina, Margarita; Alfosea-Simón, Marina; Lucarelli, Franco; Kováts, Nora; Ryšavý, Jiří; Feliciano, Manuel; Alves, CéliaThe European Union has implemented policies to promote renewable energy, with an emphasis on biomass for heat generation. However, residential biomass combustion is a major source of particulate matter (PM10), and its chemical constituents pose health concerns worldwide. This study characterised the organic and inorganic composition, oxidative potential (OP), and ecotoxicity of PM10 indoors and outdoors during the operation of two heating appliances fuelled with different types of biomasses: a modern hydronic stove and a traditional wood stove. PM10 concentrations were higher in the room equipped with the traditional system during the combustion of briquettes (95.9 f 74.9 mu g m-3) and firewood (50.1 f 25.6 mu g m- 3), compared to the modern stove using pellets (27.1 f 11.8 mu g m-3) and olive stone (23.0 f 4.5 mu g m- 3). While element oxides accounted for similar PM10 mass fractions (7 %), the wood stove produced higher levels of organic constituents, including carbonaceous fractions, polycyclic aromatic hydrocarbons (PAHs), quinones and saccharides. Significant correlations between OP assays and concentrations of PAHs, quinones and phenolic compounds were found in the room equipped with wood stove, with indoor to outdoor (I/O) ratios higher than 1. In contrast, I/O ratios below 1 were observed for OP in PM10 samples collected during hydronic stove operation. Ecotoxicity assays using Aliivibrio fischeri classified indoor PM10 from the wood stove as 'very toxic', whereas samples from the hydronic stove exhibited lower toxicity and OP levels. These findings highlight the need to reconcile renewable energy goals with air quality and public health.
- Experimental study of thermo-environmental properties of single and double-chambered bioethanol burnersPublication . Ryšavý, Jiří; Vicente, Estela Alexandra Domingos; Molchanov, Oleksandr; Cipoli, Yago Alonso; Krpec, Kamil; Alves, Célia A.; Feliciano, Manuel; Dargham, Imane; Kuo, Jenn-Kun; Wang, Cheng-ChiBioethanol burners are becoming increasingly popular across Europe, often valued primarily for their aesthetic appeal; however, their potential role in household energy systems and their influence on the indoor environment have been largely overlooked. This study aimed to evaluate the effects of burner design, burner opening area regulation, fuel quality, and initial fuel dose on key operational and environmental performance metrics, including heat output, pollutant emission rates, and impact on indoor environment, for single- and doublechambered bioethanol burners. The results showed that single-chambered burners achieved 11-31 % higher average heat output and 8-27 % higher maximum heat output despite having a lower burner opening area. Regarding emissions, single-chambered burners exhibited lower CO emission factors (5-51 % reduction) but higher NOx emission factors (13-23 % increase) compared to double-chambered burners. Indoors, a similar trend was observed, with single-chambered burners contributing to lower CO levels but higher NOx concentrations. These findings provide new insights into how burner geometry directly affects combustion efficiency and pollutant formation mechanisms, including thermal NOx and incomplete combustion processes. This study is one of the few to combine controlled hood testing with real-room experiments, offering a comprehensive assessment of the indoor air quality implications of ethanol burner operation. The results of this study highlight the necessity for further research and development to mitigate potential health risks while maximising the efficiency of bioethanol burners as a viable household heating solution.
- Integrated experimental, process simulation, and techno-economic assessment of biogas upgrading via pressure/vacuum swing adsorptionPublication . Karimi, Mohsen; Siqueira, Rafael M.; Shirzad, Mohammad; Ferreira, Alexandre F.P.; Rodrigues, Alírio; Silva, José A.C.This study presents an integrated approach in biogas upgrading technology through the development and optimization of a shaped MIL-160(Al)-based pressure/vacuum swing adsorption (PSA/VPSA) system. Combining detailed experimental investigations with comprehensive process modeling and techno-economic analysis, we demonstrate a complete pathway from fundamental dynamic adsorption to industrial implementation. Breakthrough tests reveal notable CO2/CH2 separation performance with shaped MIL-160(Al), while 23 cyclic PSA experiments achieved over 90 % methane purity. Advanced process modeling, validated with less than 5 % deviation from experimental data, enables successful scale-up to industrial VPSA configurations, where 38 distinct cases were evaluated to identify an optimal system producing 99.81 % pipeline-quality biomethane with 92.6 % recovery. Our holistic techno-economic assessment reveals the system's acceptable economic viability, with the total capital expenditure (CapEx) of $14.33 million. Accordingly, this work provides clear methodological insights that strengthen the understanding of MIL-160(Al)-based PSA/VPSA process and support its potential application for biogas upgrading.
- Purificação a seco do biodiesel etanólico através de adsorção utilizando materiais à base de casca de amêndoaPublication . Mezzalira, Melissa Giacomet; Gomes, Maria Carolina Sérgi; Queiroz, Ana; Brito, Paulo; Ribeiro, António E.O crescente interesse por fontes de energia sustentáveis tem impulsionado a busca por alternativas aos combustíveis fósseis. Nesse contexto, o biodiesel surge como uma possível alternativa ao diesel, devido às suas propriedades compatíveis.1 Esse biocombustível pode ser obtido a partir de diversas matérias-primas, incluindo o óleo alimentar usado (OAU), promovendo o reaproveitamento eficiente de resíduos.2 A purificação do biodiesel é geralmente realizada por lavagem com água, embora eficaz, gera grandes volumes de efluentes. Dessa forma, o uso de materiais adsorventes surge como uma alternativa mais limpa e sustentável para a remoção de contaminantes como o glicerol. Neste trabalho, o processo foi dividido em três fases: produção do biodiesel, preparação e caracterização do adsorvente a partir de cascas de amêndoa e estudos de adsorção.
- Techno-Economic and Energy Assessment of the Pressure Swing Adsorption Process for CO2Capture from Flue Gas Using Shaped MOF MIL-160(Al): Bridging Experimental Results into Industrial ImplementationPublication . Karimi, Mohsen; Shirzad, Mohammad; Siqueira, Rafael M.; Ferreira, Alexandre; Silva, José A.C.; Rodrigues, AlírioThis work provides an integrated techno-economic and energy assessment of vacuum pressure swing adsorption (VPSA) for postcombustion CO2 capture, bridging laboratory-scale validation with industrial-scale design. The shaped MOF MIL-160(Al) was evaluated through 19 dynamic PSA experiments, which clarified the distinct roles of purge and rinse steps in determining the separation efficiency. The validated process model reliably captured cyclic steady-state dynamics and was extended to simulate 31 industrial VPSA configurations. The results demonstrated that as purge flow increased from 500 to 7.5 & times; 103 L/min, CO2 purity reduced from 91% to 82%, but CO2 recovery increased from 65% to 96%, which corresponds to an enhancement in energy consumption from 1589.2 to 1655 kWh. On the other hand, when rinse flow enhanced from 30 & times; 103 to 39 & times; 103 L/min, CO2 purity increased from 82% to 89%, while CO2 recovery reduced from 90% to 86% and energy consumption increased from 1573.5 to 1657.9 kWh. Techno-economic analysis estimated a total capital investment of $18.89 M and an annualized capital expenditure (CapEx) of $1.82 M & centerdot;yr-1, with operating costs dominated by electricity consumption and, to a lesser extent, labor cost. Overall, the findings prove that industrially viable deployment of MIL-160(Al)-based VPSA requires a combined focus on plant equipment lifetime and process-level energy optimization, thereby providing a clear roadmap for translating experimental performance into large-scale CO2 capture.
- Valorisation of waste cooking oils through [HMIM][HSO4] ionic liquid-catalysed biodiesel conversionPublication . Brito, Paulo; Diniz, Heloísa Oliveira Resende; Queiroz, Ana; Ribeiro, António E.Biodiesel consists of a mixture of fatty acid methyl esters (FAMEs) and is produced by processing vegetable oils or animal fats. Oil sources, not competing with the food market, such as waste cooking oils (WCOs), can be used, and ionic liquids (ILs) are promising catalysts, since they promote esterification/transesterification reactions to biodiesel. The objective was to study biodiesel production using 1-methylimidazolium hydrogen sulphate IL ([HMIM][HSO4]) as a catalyst in esterification/transesterification reactions with methanol, for oleic acid (OA) and simulated high acidic oils, in mixtures of 40%(w/w) OA to 60%(w/w) WCO. The IL recovery procedure was also assessed using water as solvent. Biodiesel production was carried out on two heating plates with automatic temperature control and magnetic stirring (IKA, digital C-MAG HS4 model, and VWR, VMS-C4 model). A centrifuge (SIGMA, model 2-4) was used for phase separation. Samples were dried in an oven (CIENTIFIC, series 9000) and all masses were measured on an analytical balance (accuracy: ±0.0002g and maximum: 210g; AE, ADA 210/C). FAME content was determined by GC (SHIMADZU, Nexis GC 2030), with FID, an AOC-20i autoinjector and an Optima BioDiesel F capillary column (30mx0.25mm). Analyses were carried out by FTIR with a Perkin Elmer equipment, Spectrum Two, and an ATR universal accessory. Reaction conditions were as follows: 65°C, 4 hr, raw-material/methanol molar ratio 1:10, and 10%(w/w) IL load. Using OA as the raw material, an acidity drop conversion of 81.2% was obtained. After seven reaction cycles, the conversion dropped to 69.4%, while the FAME content decreased from 64.7% to 57.5%. For WCO, a conversion of 45.6% was obtained and after nine reaction cycles it decreased to 27.2%, while the biodiesel FAME content decreased from 24.1% to 14.0%. The FTIR correlation between initial and final IL samples was 99.3% for OA and 90.0% for WCO, showing that the recovery method is efficient. For these operating conditions, IL only promotes esterification reactions.
- Viable Metal–Organic Framework Adsorbents for Thermodynamics-Driven Methane/Hydrogen SeparationPublication . Dutta, Prantar; Henrique, Adriano; Mandal, Writakshi; Bueno, Laura; Pinto, Rosana V.; Magnin, Yann; Barbouteau, Sandra; Mouchaham, Georges; Serre, Christian; Silva, José A.C.; Maurin, GuillaumeHydrogen is a clean energy carrier that supports low-carbon mobility and power generation and is widely used in oil refining and methanol production. Efficient separation of methane (CH4) from hydrogen (H-2) is critical in the hydrogen supply chain, particularly for H-2 purification after steam methane reforming and H-2 recovery from natural gas pipelines. In this work, atomistic simulations were employed to systematically evaluate a diverse set of existing metal-organic frameworks (MOFs) for physisorption-based CH4/H-2 separation under realistic pressure swing adsorption (PSA) conditions. The selected MOFs combine favorable chemical and geometrical features with practical advantages including synthetic feasibility, stability, environmental sustainability, and scalability. Force field Monte Carlo simulations were deployed to predict single-component and mixture adsorption isotherms of CH4 and H-2, as well as their adsorption enthalpies at zero coverage, with the approach validated against experimental adsorption and breakthrough data for selected materials. Several MOFs were predicted to outperform the commercial adsorbent Zeolite 13X, exhibiting superior separation performance in terms of CH4/H-2 selectivity and CH4 working capacity. Structure-property analysis revealed key relationships between pore architecture, chemical functionality, and separation performance. Furthermore, molecular dynamics simulations of CH4 diffusion in the MOF pores confirmed the kinetic suitability of top-performing materials for PSA operation. Overall, this study identifies a set of viable MOFs as promising candidates for efficient CH4/H-2 separation and provides molecular-level insights to guide the development of hydrogen purification technologies.