Loading...
22 results
Search Results
Now showing 1 - 10 of 22
- Resultados e conclusões do GTAER : Grupo de Trabalho para a definição das Áreas de Aceleração de Energias RenováveisPublication . Simoes, Sofia; Barbosa, Juliana; Oliveira, Paula; Quental, Lídia; Simões, Teresa; Catarino, Justina; Rodrigues, Carlos; Costa, Paula; Patinha, Pedro; Picado, AnaRESUMO: Este documento apresenta os resultados e conclusões do GTAER (Grupo de Trabalho para a definição das áreas de Aceleração de Energias Renováveis) criado pelo Despacho n.º 11912/2023. Uma parte importante do documento foca o objetivo de consolidar e robustecer o trabalho realizado na identificação das áreas com menor sensibilidade para a localização de unidades de produção de eletricidade renovável. Este trabalho desenvolve-se na sequência do trabalho anteriormente realizado pelo grupo de trabalho informal em atividade entre setembro de 2022 e janeiro de 2023 e que foi alvo de atualização pelo LNEG em junho de 2023. São também apresentados elementos no que respeita a: • potencial de implementação de unidades de geração em superfícies artificializadas; • proposta das áreas de aceleração de energias renováveis; • proposta de regras adequadas à implementação dos projetos de energias renováveis nestas áreas e as medidas de mitigação aplicáveis; • proposta de método de disponibilização pública das áreas de aceleração de energias renováveis a designar, bem como a metodologia para a sua revisão e a periodicidade associada.
- The effect of shredding and particle size in physical and chemical processing of printed circuit boards wastePublication . Oliveira, Paula; Taborda, F. Charters; Nogueira, Carlos; Margarido, F.Circuit boards present in most electric and electronic devices are very important components, which should be removed during sorting and dismantling operations in order to allow further adequate treatment for recovering valuable metals such as copper, nickel, zinc, lead, tin and rare elements. This recovery can be made by physical and chemical processes being size reduction by shredding the first step. In this paper, the effect of particle size in physical and chemical processing of printed circuit boards is presented and discussed. Shredding using cutting-based equipment allowed the comminution of boards and the liberation of particles composed by different materials (mainly metals and resin). Particle sizes less than 1 mm seems to be appropriate to attain high liberation of materials, which is crucial for the physical separation using gravity or electrostatic processes. Concerning chemical treatment, hydrometallurgical processing involves a leaching operation which can be also influenced by particle size of shredded boards. Samples with different granulometries were leached with 1 M HNO3 solutions, being leaching yields evaluated. It was concluded that particle size can be an important factor for the solubilization of some metals, but the effect is not similar for all elements. When average diameters change from 2.0 to 0.20 mm, nickel, aluminium and tin reactivity were not significantly affected, being this effect important for copper. Zinc behavior was very dependent from extreme particle sizes but was less affected in intermediate granulometries. Lead leaching showed also a peculiar behavior, exhibiting high and almost constant yields (80-90%) for particle size of solids up to 1.2 mm, and decreasing suddenly for higher granulometries. The effect of time on chemical reactivity for samples with different granulometries demonstrated that particle size affects reaction rates but eventually similar efficiencies can be obtained for long time periods. Therefore the relationship between results from shredding operation and chemical leaching step needs to be optimized, considering the balance between factors like consumption of energy during grinding operation and residence time in leaching.
- Valorização de placas de circuito impresso por hidrometalurgiaPublication . Oliveira, PaulaEste trabalho consistiu no desenvolvimento de um processo de valorização de placas de circuito impresso (PCI's) em fim de vida, por hidrometalurgia, tendo como objectivo recuperar o cobre, metal que existe em maior concentração na sua composição. As PCI's são componentes importantes dos resíduos de equipamentos eléctricos e electrónicos (REEE) devido não só ao valor dos materiais que as compõem mas também à toxicidade de alguns dos seus constituintes. A reciclagem deste resíduo possibilita a recuperação dos materiais aí contidos nomeadamente os da fracção metálica, com os benefícios económicos subjacentes, evitando os problemas e custos associados à deposição em aterro e contribuindo para a preservação dos recursos naturais. O processo de tratamento das PCI's consistiu na aplicação de tecnologias de natureza física e química, envolvendo várias etapas: fragmentação, lixiviação em meio nítrico, separação e purificação do cobre por extracção por solventes e recuperação do cobre por cristalização. Após tratamento físico, por fragmentação e crivagem do material obtido, procedeu-se à caracterização química das fracções, para determinar a composição elementar e a distribuição dos metais.O processo químico, que consistiu a parte principal deste trabalho, envolveu o estudo e optimização do processo de lixiviação em meio nítrico com vista a maximizar a recuperação do cobre. Foi estudada a influência de vários factores tais como a temperatura de lixiviação, concentração do lixiviante, relação líquido/sólido, agitação e granulometria do material, tendo-se verificado qua a temperatura e a concentração foram os factores mais significativos, obtendo-se rendimentos mais elevados para valores de temperatura e concentração do lixiviante maiores.
- Separation of non-ferrous frations of shredded end-of-life vehicles for valorising its alloysPublication . Margarido, F.; Santos, R. Novais; Durão, F.; Guimarães, C.; Nogueira, Carlos; Oliveira, Paula; Pedrosa, Fátima; Gonçalves, Ana MariaWorldwide the end-of-life vehicles (ELV) generate millions of tons of waste, requiring an adequate and efficient management. The non-ferrous fraction contains essentially aluminium, magnesium and copper alloys, being valorised by metallurgical processors to obtain new metals and alloys. However most of the recovered metals are downcycled, as is the case of aluminium where the recycled products are essentially used to produce less purity casting alloys. New or improved separation technologies are therefore necessary in order to allow an accurate separation of alloys or alloy groups, increasing the value of the non-ferrous streams. In this paper, the composition of the non-ferrous fractions of ELV shredders are assessed with particular relevance for the aluminium and magnesium alloys. Essentially, the main cast and wrought alloys are characterized and their markets and applications are discussed. Based on waste composition, several physical separation and sorting technologies can be applied to improve the products quality, which are here depicted and discussed. Physical processing includes operations such as eddy current and heavy media separations. For sorting alloys contained in the non-ferrous stream, other sensor-based technologies are being developed, such as electromagnetic sensing and novel laser induced breakdown spectroscopy systems, constituting an important contribution for boosting the non-ferrous metals recycling rates.
- Estimativa de potenciais técnicos de energia renovável em Portugal: eólico, solar fotovoltaico, solar concentrado, biomassa e oceanosPublication . Simoes, Sofia; Simões, Teresa; Barbosa, Juliana; Rodrigues, Carlos; Azevedo, Pedro; Cardoso, João P.; Facão, Jorge; Costa, Paula Silva; Justino, Paulo Alexandre; Gírio, Francisco; Reis, Alberto; Passarinho, Paula; Duarte, Luís C.; Moura, Patrícia; Abreu, Mariana; Estanqueiro, Ana; Couto, António; Oliveira, Paula; Quental, Lídia; Patinha, Pedro; Catarino, Justina; Picado, AnaExecutive Summary: There is a clear need to accelerate the energy transition, including the implementation of renewable electricity production plants, as well as the increase in consumption of other renewable energy carriers in buildings, industry, transport and other sectors. This work provides key information to make this transition possible, that is, the technical renewable energy potentials for Portugal. The aim is thus to contribute to policy support, as well as to decision-making by various Portuguese stakeholders (public and private) in the domains of energy, energy transition and greenhouse gases emissions mitigation. The work presents the technical renewable energy potentials for Portugal to: (i) decentralized solar photovoltaic (PV) plants in artificialized (or built-up) areas; (ii) centralized solar PV plants in non-artificialized (or natural) areas; (iii) concentrated solar power; (iv) onshore wind; (v) offshore wind (floating and fixed); (vi) bioenergy, and (vii) solar thermal. The wave energy primary energy resource potential is also presented (not the technical potential). The technical potential values of renewable energy sources (RES) presented are dynamic values, given the substantial uncertainty associated with their estimation. The study identifies technical RES potentials i.e., the technically viable energy generation achievable from a specific technology, considering the primary energy resource available and the geographic, environmental and land use limitations. RES economic potentials represent the fraction of RES technical potential that is economically viable, but they are not presented in this work. Likewise, this report does not address market potential, that translate the capacity and energy generation that the market effectively manages to implement. The presented RES technical potentials include the total capacity currently installed in the country. The technical potentials are estimated mostly for mainland Portugal, in most cases with a spatial disaggregation of at least NUT2 and sometimes for NUT5 and/or type of building. Despite adopting an approach based on a territorial analysis in which some areas of the country are excluded, this potential does not correspond to the work done in mapping less-sensitive areas towards future definition of RES “Go-To Areas”. The decentralized solar PV potential in artificialized areas is divided into 6 area types: industrial areas; commercial buildings; residential and mixed-use buildings; villas; health, education, cultural, tourist and military buildings, and other land uses (including parking lots and patios, ports, waste and wastewater treatment infrastructure, sports facilities, among others). It is estimated a technical potential of 23.33 GW that could generate up to 36.84 TWh/year. This potential is distributed throughout the entire territory of mainland Portugal but is higher in the North and Center regions. The RES technical potential for centralized solar PV was estimated as a range of values that translate the uncertainty associated with using different levels of concern in excluding certain areas in which solar PV can be deployed (for example to safeguard ecosystems, water resources, agriculture or archaeological heritage). The centralized solar PV potential varies between 168.82 GW and 45.63 GW. The maximum threshold of installed capacity could generate 278.11 TWh/year of electricity. The value is high and reflects on the one hand, the excellence of the solar resource throughout the country, and on the other, the large size of the considered areas. The CSP potential is 62.6 GW with a corresponding electrical production potential of 183.61 TWh/year. It is mainly located in the Alentejo region, although other areas have also been identified in other regions of the country. The wind onshore technical potential is 15.7 GW, that could generate 37.13 TWh/year, taking into account the safeguarding of various areas for the protection of ecosystems and also social acceptability issues. In the case of offshore wind and considering a capacity density of 4 MW/km2 for floating offshore and 5.5 MW/km2 for fixed offshore, a total of 36 GW and 2 GW are obtained, respectively. This capacity could generate up to 126.14 TWh/year (floating offshore) or 6.31 TWh/year (fixed offshore). The solar thermal energy potential focused residential and service buildings (such as nursing homes, barracks, etc., tourism, hospitals, indoor swimming pools and other sports facilities). The potential is of 0.95 GWt and 0.95 TWh/year for service buildings, 7.26 GWt and 5.84 TWh/year for residential buildings. For industry there is a potential of 1.06 GWt, which could generate up to 1.15 TWh/year for applications up to 160 ºC. The total technical potential of solar thermal is 9.25 GWt and 7.93 TWh/year of thermal energy generated, with a substantial weight of residential buildings in the total value. Potential values are disaggregated by NUTS III and type of building. In terms of biomass and bioenergy potential, annual values of forest biomass, agricultural biomass, agro-industrial waste, urban waste and wastewater treatment are estimated, totaling around 58 TWh/year. Regarding the production of biofuels (HVO and FAME) it is estimated that the annual production of domestic used oils and other similar residues is 1.4 TWh/year. The use of oils from food crops such as soybean, sunflower and rapeseed is limited by European (and national) policy guidelines and is 2.1 TWh/year. Regarding wave energy, the resource potential is estimated between 1.4 GW for 80 m bathymetry and 4.8 for 20 m bathymetry. There are substantial uncertainties associated with the presented values, inherent to the methodological approach considered. Nevertheless, these estimates are a valuable starting point to be refined and improved in subsequent updates.
- eMaPriCe - Estudo de Matérias-Primas Críticas e estratégicas e economia circular em PortugalPublication . Simoes, Sofia; Sousa Rocha, Cristina; Alexandre, Jorge; Catarino, Justina; Ferreira, Cristina; Oliveira, Paula; Amorim, Filipa; Niza, Samuel; Nogueira, CarlosRESUMO: O eMaPriCe tem por objetivo identificar oportunidades de implementação de estratégias de Economia Circular (EC), a fim de evitar que as Matérias-Primas Críticas (MPC) se transformem em resíduos, bem como opções da substituição destas por matérias-primas não críticas. Este estudo pretende também apresentar estratégias de recuperação das MPC presentes nos resíduos, dando assim resposta à Diretiva-Quadro Resíduos. O estudo focou-se nas 30 MPC na lista Europeia, bem como a cortiça natural, uma matéria-prima estratégica para Portugal, visto ser o seu maior produtor mundial. Estas 31 matérias-primas são designadas como MPC+. Foi feito uma identificação das aplicações na economia Portuguesa das MPC+ para os setores Têxteis e calçado; Cerâmica; Cortiça; Exploração mineira; Químicos e fertilizantes; Equipamentos elétricos e eletrónicos (EEE); Energias renováveis e Automóvel. Todas as MPC na lista europeia são utilizadas em Portugal para os setores considerados. O setor com maior diversidade na utilização de MPC+ é o setor dos EEE (26 MPC+), seguindo-se os setores químico e automóvel (24 MPC+ cada), e os têxteis (21 MPC+). As energias renováveis e cerâmica utilizam 14 e 13 MPC+, respetivamente, enquanto o calçado utiliza 11 MPC+. Por fim, tanto o setor da cortiça como da exploração mineira recorrem a apenas 2 MPC+ cada.
- Prevenção de resíduos numa perspetiva de minimização de custos dos desperdícios: estudo de caso numa empresa de curtumesPublication . Nogueira, Carlos; Silva, Nuno; Oliveira, PaulaA prevenção de resíduos é uma das ferramentas de ecoeficiência dos processos industriais. No âmbito do projeto PRERESI, desenvolveram-se metodologias de abordagem à prevenção na ótica do “zero de resíduos”, privilegiando a contabilização dos desperdícios por operação unitária e as perdas económicas a eles associadas. A hierarquização das operações por relevância permite identificar oportunidades de intervenção para obter melhorias, nomeadamente diminuindo desperdícios e potenciando benefícios económicos. Este artigo descreve sucintamente a aplicação desta metodologia a uma empresa do setor dos curtumes.
- Oxidative leaching process with cupric ion in hydrochloric acid mediafor recovery of Pd and Rh from spent catalytic convertersPublication . Nogueira, Carlos; Paiva, A. P.; Oliveira, Paula; Costa, M. Clara; Costa, Ana M. Rosa daThe recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu2+ concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80.C, t = 4 h,[HCl] = 6 M, [Cu2+] = 0.3 M).
- Guia de implementação de produção ecoeficiente incluindo boas práticas no ambiente interno :sector dos moldes e das ferramentas especiaisPublication . Ribeiro, Catarina; Oliveira, Paula; Sota, Leonor; Gonçalves, Lucinda; Pedrosa, Fátima; Barroca, Paulo; Neves, António Baeta; Crujeira, Teresa; Salema, David; Pereira, Rui; Mendes, Timóteo; Figueiredo, José Manuel [ed.]; Partidário, Paulo Jorge
- Leaching studies for metals recovery from printed circuit boards scrapPublication . Oliveira, Paula; Cabral, Marta; Taborda, F. Charters; Margarido, F.; Nogueira, CarlosIn this paper, the leaching behavior of the major metals present in printed circuit boards waste is evaluated, aiming at its recycling by hydrometallurgy. Several leachants were compared (sulfuric, hydrochloric and nitric acids, at 2 M H+ concentration), at temperatures of 25ºC and 90ºC and 4 hours of reaction time. Sulfuric acid leaching was not very promising concerning metals dissolution being only effective for iron. Hydrochloric acid allowed the leaching up to 60% of tin and about 50% of lead, as well as the iron. Nitric acid was the most efficient leachant due to its oxidizing properties. Recoveries of 90% or more for copper, iron, nickel and zinc were achieved at the higher temperature. Lead was also dissolved (up to 80%), as well as silver (more than 70%). These results show that the hydrometallurgical recovery of most of the metals present in PCB’s scrap is a technically feasible alternative that shall be considered and evaluated.
- «
- 1 (current)
- 2
- 3
- »