A carregar...
Publicação
Centrais de biomassa - Avaliação da solução de mistura das cinzas com composto orgânico
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 3.23 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
A presente dissertação tem como objetivo avaliar as características que resultaram no composto orgânico “AMARTERRA” após adição, em diferentes percentagens, de cinzas de fundo provenientes da combustão da biomassa na Central Termoelétrica de Biomassa das Terras de Santa Maria S.A. O composto “AMARTERRA”, proveniente da central de Tratamento Mecânico Biológico (TMB) localizada no Ecoparque de Setúbal, resulta da compostagem da fração orgânica dos resíduos urbanos indiferenciados (após separação mecânica na linha de processo da TM), em pilhas assentes sobre caleiras com sistema de arejamento forçado, no edifício de compostagem. No processo de combustão da biomassa para a obtenção de energia a partir de caldeira, são formados dois subprodutos: as cinzas de fundo (escórias) e as cinzas volantes. As cinzas são retiradas em diferentes zonas da central e armazenadas por tipologia, em locais diferenciados. No que respeita às cinzas de fundo estas têm como destino final o aterro de resíduos industriais, face às suas características e legislação em vigor.
As experiências laboratoriais que foram realizadas incidiram sobre amostras de cinzas de fundo adicionadas ao composto maturado, em quantidade [peso cinzas de fundo/peso total] de 10%, 20% e 30%, tendo incidido sobre os seguintes parâmetros: pH em água, condutividade elétrica, humidade, matéria orgânica, granulometria, massa volúmica aparente e os metais pesados. Relativamente à determinação da quantidade de metais pesados, devido à elevada reatividade que inviabilizou a digestão ácida das amostras, não foi possível finalizar a sua concretização.
Previamente às misturas efetuadas, procedeu-se à avaliação das características do composto e das cinzas de fundo, de forma a se detetarem as posteriores alterações em cada uma das amostras analisadas. No que se refere às características empíricas do composto assinala-se que este possuía um odor ligeiro a amoníaco e a sua granulometria era consideravelmente granular. A sua maturação foi classificada como “fresca de grau I ou II” após analisado através do teste do auto-aquecimento. Observando as análises realizadas às cinzas de fundo pela empresa no seu processo de monitorização, verifica-se que possuíam uma baixa quantidade de metais pesados, possuindo um pH alcalino, uma baixa condutividade elétrica, humidade elevada e uma significativa percentagem de matéria orgânica. Relativamente às análises realizadas ao composto pela AMARSUL concluiu-se que este se inseria na categoria II.
Em conclusão do trabalho desenvolvido, considera-se que esta investigação permitiu obter informações que poderão futuramente ajudar a encontrar a solução mais equilibrada para a valorização de um subproduto que tem potencial para otimizar as características do composto orgânico. Deste modo, será possível evitar a deposição de cinzas de fundo em aterros, atendendo assim aos objetivos de uma verdadeira Economia Circular que necessita ser dinamizada.
This thesis’ goal is to evaluate the characteristics that result in the organic compost “AMARTERRA” after mixing different percentages of bottom ashes generated by the combustion of biomass at the Biomass Plant of Terras de Santa Maria, S.A. The “AMARTERRA” compost results from the organic fraction of the domestic waste (after mechanical separation forwarded to the mechanical treatment line), stored in piles laying on gutters with forced air on the composting building. On the other hand, the bottom ashes obtained from the Biomass Plant of Terras de Santa Maria, are the result of the combustion of biomass through a boiler to retrieve electric power, in which two by-products are formed: the bottom ashes and the fly ashes. The ashes are removed in different areas of the plant and stored, by typology, in different places. Regarding the bottom ashes, these have as final disposal the industrial waste landfill, given its characteristics and national legislation. The laboratory experiments that were performed focused on the addition of ashes to the final compost, in the selected amounts [bottom ashes weight/total weight] of 10%, 20% and 30%. The following parameters were analyzed: pH in water, electrical conductivity, moisture, organic matter, granulometry, apparent bulk density and heavy metals. Heavy metals’ content determination was not possible due to high reactivity during the acidic digestion which, in turn, rendered the sample unviable. An assessment of the compost’s characteristics and bottom ashes was performed to verify alterations in the analyzed samples. As for the compost’s empirical characteristics, a grainy texture and a light smell of ammonia were identified. The maturation of the compost was classified as “category I or II fresh”, analyzed through self-heating test. Through analysis of the bottom ashes for the company’s monitorization process, it was possible to observe low heavy metals’ content, with an alkaline pH, low electric conductivity, high moisture, and significant organic matter. Regarding the analyzes carried out on the compost by AMARSUL, it was concluded that it fell into category II. In conclusion, this investigation allowed obtaining information that may in the future help to find the most balanced solution for the valorization of a by-product that has the potential to optimize the characteristics of organic compost. In this way, the deposition of bottom ash in landfills can be avoided, thus meeting the objectives of a circular economy in this regard.
This thesis’ goal is to evaluate the characteristics that result in the organic compost “AMARTERRA” after mixing different percentages of bottom ashes generated by the combustion of biomass at the Biomass Plant of Terras de Santa Maria, S.A. The “AMARTERRA” compost results from the organic fraction of the domestic waste (after mechanical separation forwarded to the mechanical treatment line), stored in piles laying on gutters with forced air on the composting building. On the other hand, the bottom ashes obtained from the Biomass Plant of Terras de Santa Maria, are the result of the combustion of biomass through a boiler to retrieve electric power, in which two by-products are formed: the bottom ashes and the fly ashes. The ashes are removed in different areas of the plant and stored, by typology, in different places. Regarding the bottom ashes, these have as final disposal the industrial waste landfill, given its characteristics and national legislation. The laboratory experiments that were performed focused on the addition of ashes to the final compost, in the selected amounts [bottom ashes weight/total weight] of 10%, 20% and 30%. The following parameters were analyzed: pH in water, electrical conductivity, moisture, organic matter, granulometry, apparent bulk density and heavy metals. Heavy metals’ content determination was not possible due to high reactivity during the acidic digestion which, in turn, rendered the sample unviable. An assessment of the compost’s characteristics and bottom ashes was performed to verify alterations in the analyzed samples. As for the compost’s empirical characteristics, a grainy texture and a light smell of ammonia were identified. The maturation of the compost was classified as “category I or II fresh”, analyzed through self-heating test. Through analysis of the bottom ashes for the company’s monitorization process, it was possible to observe low heavy metals’ content, with an alkaline pH, low electric conductivity, high moisture, and significant organic matter. Regarding the analyzes carried out on the compost by AMARSUL, it was concluded that it fell into category II. In conclusion, this investigation allowed obtaining information that may in the future help to find the most balanced solution for the valorization of a by-product that has the potential to optimize the characteristics of organic compost. In this way, the deposition of bottom ash in landfills can be avoided, thus meeting the objectives of a circular economy in this regard.
Descrição
Palavras-chave
Composto orgânico cinzas de fundo cinzas volantes pH condutividade elétrica metais pesados