Browsing by Author "Cabrita, Isabel"
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- Associar a eliminação de resíduos à produção de combustíveis: Forma de garantir um futuro sustentável?Publication . Pinto, Filomena; Cabrita, Isabel
- Avaliação do potencial e impacto do biometano em PortugalPublication . Cabrita, Isabel; Silva, Luís; Di Berardino, Santino; Gírio, Francisco; Marques, Isabel PaulaABSTRACT: O PNAER 2020, D.R. 1ª Série Nº 70, de 10 de Abril 2013, identifica políticas e atividades necessárias implementar para garantir o cumprimento do plano nacional relativamente à promoção da utilização das fontes de energia renovável nos diferentes setores. Uma das áreas estratégicas a promover refere-se ao “Biometano”, apresentando como objetivo a avaliação do potencial do biometano em Portugal e suas aplicações alternativas em apoio à definição de regulamentação das especificações necessárias para a sua injeção na rede de gás natural (GN). Com esta avaliação prevê-se possibilitar a utilização de biometano para outros fins para além da produção de eletricidade. Recentemente publicada, a Diretiva 2014/94/UE do Parlamento Europeu e do Conselho de 22 de Outubro de 2014 estabelece princípios orientadores relativamente à criação de uma infraestrutura para combustíveis alternativos na Europa, a qual promove a existência de postos de abastecimento de combustíveis alternativos para o setor de transportes em que se inclui o biometano. Duas situações poderão ser consideradas: a introdução de biometano na atual rede de distribuição de gás natural (GN); a existência de uma rede de postos de abastecimento locais que utilizem biometano produzido localmente ou em locais mais remotos tirando partido da logística de distribuição de gás através de camiões cisterna implementada para o GN.
- Avaliação do potencial e impacto do biometano em Portugal: Sumário executivoPublication . Cabrita, Isabel; Silva, Luís; Di Berardino, Santino; Gírio, Francisco; Marques, Isabel Paula
- Biomass Fuels in SOFCPublication . Cabrita, IsabelResulting from growing concerns on climate change and resources depletion, biomass has gained increased importance. Security of supply, better environment and economic development, as worldwide goals, are usually drivers for economic growth. Technology developments have adequately not responded to challenges to diversify resources to substitute carbon-intensive fossil fuels at competitive prices. State-of-the-art energy technologies, although advanced, are facing constraints, justifying icreasing effosts in demonstrating efficient and more environmentally friendly tecnhologies.
- Biorefineries : a new concept for biomass based industriesPublication . Cabrita, Isabel; Nunes, Clemente Pedro; Sousa, Gabriel; Matos, Henrique A.
- CO2 and NOx reduction in combustion systemsPublication . Cabrita, Isabel; Azevedo, Pedro; Gulyurtlu, Ibrahim
- Energia e sustentabilidadePublication . Cabrita, Isabel; Azevedo, Pedro; Crujeira, Teresa; Guerreiro, Isabel
- Fluidised bed combustion of two species of energy cropsPublication . Abelha, Pedro; Franco, Carlos; Lopes, Helena; Gulyurtlu, Ibrahim; Cabrita, IsabelThe use of biomass fuels for energy production through combustion has a growing application worldwide mainly for two reasons: first, the utilization of biomass for energy contributes to mitigate emission of green house gases; second, its use decreases the dependence of imported fossil fuels in Europe. The objective of this work was to study the combustion behaviour of two endogenous biomass species: cardoon (cynara cardunculus) and arundo (arundo donax), which were specially produced in energy crops plantations. Mixtures of cardoon and a forestry biomass specie (eucalyptus) were also studied to evaluate potential benefits from synergies between both biomass fuel types. The results showed that the utilization of cardoon, in pelletized form, and loose arundo as feedstock, did not give rise to any operational problems related with the feeding system. It was verified that the mono combustion of cardoon could pose problems at industrial scale in fluidised bed systems, considering the high levels of HCl and NOX emissions obtained and tendency to sinter the bed sand material. The addition of the forestry biomass to cardoon appeared to prevent the bed agglomeration problem. Furthermore, both the NOX and SO2 emissions were found to decrease at the same time suggesting potential synergy of blending different types of biomass regarding pollutant emissions and in bed agglomeration problems.
- Gasification study of cynara cardunculus to produce hydrogen rich gasPublication . Franco, Carlos; Lopes, Helena; Pinto, Filomena; Andre, Rui N.; Gulyurtlu, Ibrahim; Cabrita, IsabelThe need to substitute fossil fuel feedstocks with endogeneous biomass to produce energy with lower environmental impact makes necessary to develop innovative and technologically more advanced processes for energy production. Gasification of Cynara cardunculus L. (cardoon) alone and mixed with Eucalyptus was carried out in a bench scale fluidized bed gasifier to study the influence of operating parameters that could lead to a gas rich in hydrogen. The gasification tests were carried out using a mixture of oxygen and steam, as gasifying agent, to avoid the dilution effect of nitrogen that exists in air. The effect of catalysts addition to the bed on gas composition was analyzed as well as the influence in the level of contaminants like H2S, HCl, NH3 and tars in the gas produced. Steam and temperature had a positive effect by promoting the hydrogen production. The higher heating value of the gas produced was determined to be in the range 12 – 15 kJ/nm3 in a dry-nitrogen-free basis. Cardoon contains N, S and Cl which may give rise to problems during the gasification process and to the eventual use of the syngas produced. The results obtained showed that the presence of contaminants could be decreased through retention in the solid phase and by employing a condensation system to separate out pollutants in the liquid phase. This paper will fully present and discuss the results obtained with the gasification of cynara cardunculus and eucalyptus in a fluidized bed gasifier.
- Industry-based biorefineriesPublication . Cabrita, Isabel; Carvalheiro, Florbela; Duarte, Luís C.; Gírio, Francisco; Lukasik, Rafal M.
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