Identification of atmospheric pollutants control mechanisms during co-combustion of coal and non-toxic wastes

Doctoral dissertation for Ph.D. degree in Sustainable Chemistr

Potencialidades da espetrometria de fluorescência de raios x na área da energia

RESUMO: A espectrometria de fluorescência de raios X em dispersão de comprimentos de onda (FRX-DCO) é uma técnica analítica comparativa, não destrutiva, que permite uma abordagem expedita para elementos de número atómico entre 9 e 92, que apresenta um baixo risco de contaminação e que é aplicável a diversos tipos de matrizes.info:eu-repo/semantics/publishedVersio

PCDD/F formation in the co-combustion with biomass and coal: the influence of chlorine, copper, calcium and sulphur

The reduction of CO2 emissions is the primary goal of partially replacing coal with Renewable Energy Sources (RES) of biomass origin, accompanied with the reduction of emissions of other pollutants. At the same time, there are advantages in mixing this particular resource - solid biomass - with coal, due to positive synergies arising from the introduction of different amounts of volatile matter, ash, sulphur, calcium, chlorine, and heavy metals. The option for the co-combustion with biomass with coal using fluidised bed technology could contribute to the fulfilment of the EU objectives in terms of environmental protection and sustainable energy production

Avaliação da conformidade do teor em enxofre em gasóleo e biodiesel

RESUMO: Os transportes rodoviários que utilizam combustíveis de origem fóssil são uma das principais fontes de emissão de poluentes para a atmosfera, conduzindo à degradação da qualidade do ar, em particular nos grandes centros urbanos. A necessidade de utilização de combustíveis de origem renovável levou ao desenvolvimento de combustíveis alternativos, que permitem a redução significativa de emissões de CO2, ou a adição de produtos de origem renovável ao gasóleo. No caso dos óxidos de enxofre, a redução dessas emissões tem sido conseguida como resultado da progressiva diminuição do teor máximo de enxofre permitido nos combustíveis rodoviários.info:eu-repo/semantics/publishedVersio

Streamlining the biodesulfurization process: development of an integrated continuous system prototype using Gordonia alkanivorans strain 1B†

ABSTRACT: Biodesulfurization is a biotechnological process that uses microorganisms as biocatalysts to actively remove sulfur from fuels. It has the potential to be cleaner and more efficient than the current industrial process, however several bottlenecks have prevented its implementation. Additionally, most works propose models based on direct cultivation on fuel, or batch production of biocatalysts followed by a processing step before application to batch biodesulfurization, which are difficult to replicate at a larger scale. Thus, there is a need for a model that can be adapted to a refining process, where fuel is being continuously produced to meet consumer needs. The main goal of this work was to develop the first bench-scale continuous biodesulfurization system that integrates biocatalyst production, biodesulfurization and fuel separation, into a single continuous process, taking advantage of the method for the continuous production of the biodesulfurization biocatalysts previously established. This system eliminates the need to process the biocatalysts and facilitates fuel separation, while mitigating some of the process bottlenecks. First, using the bacterium Gordonia alkanivorans strain 1B, continuous culture conditions were optimized to double biocatalyst production, and the produced biocatalysts were applied in batch biphasic biodesulfurization assays for a better understanding of the influence of different factors. Then, the novel integrated system was developed and evaluated using a model fuel (n-heptane + dibenzothiophene) in continuous biodesulfurization assays. With this system strain 1B surpassed its highest biodesulfurization rate, reaching 21 μmol h−1 g−1. Furthermore, by testing a recalcitrant model fuel, composed of n-heptane with dibenzothiophene and three alkylated derivatives (with 109 ppm of sulfur), 72% biodesulfurization was achieved by repeatedly passing the same fuel through the system, maintaining a constant response throughout sequential biodesulfurization cycles. Lastly, the system was also tested with real fuels (used tire/plastic pyrolysis oil; sweet and sour crude oils), revealing increased desulfurization activity. These results highlight the potential of the continuous biodesulfurization system to accelerate the transition from bench to commercial scale, contributing to the development of biodesulfurization biorefineries, centered on the valorization of sulfur-rich residues/biomasses for energy production.info:eu-repo/semantics/publishedVersio

The role of automated sorting in the recovery of aluminium alloys waste

Selected papers from the 3rd Edition of the International Conference on Wastes: Solutions, Treatments and OpportunitiesA large number of aluminium alloys with varying alloying elements are present in vehicle structures and components, as well as in other household equipment. The recycling of these alloys is nowadays processed to low quality metal products due to high level of contamination, hindering the upgrading of recycling rates. The development and application of automated sorting technologies capable to detect, select and separate different alloy types could be of crucial importance in the progression of the recycling loop. This paper addresses the importance of sorting based on a study on the characterization of Al alloys in non-ferrous fraction of shredder plants

Materiais para a energia: potencialidades da espectrometria de fluorescência de raios X

A espectrometria de fluorescência de raios X em dispersão de comprimentos de onda (XDXFR) é uma técnica analítica comparativa que permite uma abordagem expedita, não destrutiva e que apresenta um baixo risco de contaminação. Esta técnica é aplicável a materiais na avaliação de contaminantes visando a identificação da sua origem e na avaliação de conformidade (cumprimentos de especificações). Neste trabalho utilizou-se um espectrómetro WDXRF sequencial AXIOS, equipado com um gerador de 4kW, uma ampola de anti-cádoto de ródio, controlado pelo software SuperQ da PANalylical e apresenta-se e discute-se a metodologia seguida assim como se apresentam as potencialidades identificadas em resultado da utilização desta técnica

Controlo analítico de impurezas em misturas de sais fundidos usadas em tecnologias de solar concentrado: adequabilidade de métodos

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Apresentam-se métodos de ensaio para quantificar impurezas em misturas de sais fundidos que combina a cromatografia iónica para cloreto e sulfato, a análise de fluxo segmentado para nitrito, a espectrometria de absorção atómica com chama para cálcio, magnésio e sódio. As impurezas metálicas são identificadas por análise qualitativa de fluorescência de raios X. Os métodos selecionados foram adaptados dos incluídos no âmbito de acreditação do Laboratório de Biocombustíveis e Biomassa com validação do modelo matemático das funções de calibração, controlo da sua estabilidade no tempo, limites de quantificação, precisão e veracidade. Com base nos dados obtidos calculou-se a incerteza de medição. A declaração da adequabilidade dos métodos de ensaio para quantificar impurezas em sais fundidos teve por base a avaliação da conformidade do limite de quantificação em relação a limites de decisão. Estes foram calculados a partir dos valores máximos de níveis de impurezas, tendo em conta a incerteza de medição e uma regra de decisão que estabelece uma confiança elevada na aceitação correta.ABSTRACT: Test methods are presented to quantify impurities in salts mixtures combining ion chromatography for chloride and sulfate, segmented flow analysis for nitrite, flame atomic absorption spectrometry for calcium, magnesium and sodium. Impurities of metals are identified by qualitative X-ray fluorescence analysis. The methods used were adapted from those included in the accreditation scope of Laboratory of Biofuels and Biomass with validation of the mathematical model of the calibration functions and its stability over time, limits of quantification, precision and trueness. Measurement uncertainty was calculated using the validation and quality control data. The statement of the adequacy of the test methods for quantification of impurities in molten salts is based on the assessment of the conformity of the quantification limits in relation to decision limits. These were obtained from the maximum impurity levels considering the measurement uncertainty and a decision rule with a high level of confidence in correct acceptance.info:eu-repo/semantics/publishedVersio

Analytical protocol for the characterization of solid organic fractions: contribution for the biochemical and thermochemical potential assessment of biomass [Poster]

ABSTRACT: In the scope of the CONVERTE project an optimised and uniformed methodology was developed in order to better evaluate the use of endogenous biomasses for energy production by biochemical or thermochemical processes. A protocol for preparation and characterization was designed and validated by the use of biomass certified reference materials and quality control actions. Extensive analytical work was performed and the results were summarized in accordance with their relevance for either biochemical or thermochemical processes.info:eu-repo/semantics/publishedVersio