CIMO - Resumos em Proceedings Não Indexados à WoS/Scopus
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Percorrer CIMO - Resumos em Proceedings Não Indexados à WoS/Scopus 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.
- 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.
- 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.
- 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.