In this study, feed coal (FC) from the Figueira Thermoelectric Power Plant (FTPP), located in the state of Paraná (PR), Brazil was characterized by X-ray fluorescence (XRF), X-ray diffractometry (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), particle size distribution analysis by laser diffraction, loss of ignition (LOI), total carbon content (TC), pH and conductivity. FC-derived by-products (CCBs) collected at the FTPP were: bottom ash (BA), fly ash from cyclone filter (CA) and fly ash from bag filter (FA). In addition to the techniques used for feed coal characterization, CCBs were also characterized by total surface area (by using BET method), external surface area (by using laser diffraction), cation exchange capacity (CEC), bulk density, besides leaching and solubilization tests. FC sample contains 72.2% of volatile material, of which 55.3% is total carbon content. LOI, FTIR, TGA and TC analyzes corroborated with these results. The main crystalline phases in the FC sample were found to be quartz, kaolinite and pyrite. The elements As, Cr, Ni and Pb were encountered in the FC sample, indicating that the use of FTPP feed coal should be monitored due to the toxic potential of these elements. The three coal ashes were classified as class F according to ASTM and presented similar chemical composition, with total content of the main oxides (SiO2, Al2O3 and Fe2O3) above 72%. Ashes enrichment factor analysis (EF) showed that As, Zn and Pb concentrate mainly in fly ash from bag filter (FA), whereas the elements K and Mg presented higher enrichment in the bottom ash (BA) . All ashes presented quartz, mullite and magnetite as crystalline phases, as well as the same functional groups, related to the presence of humidity, organic matter and Si and Al compounds. XRD, XRF, TGA, FTIR, LOI and TC techniques were correlated and confirmed the obtained results. Total and external surface area values of CCBs were related to the total carbon content (TC), as well as to the results of particle size distribution and the scanning electron micrographs of the samples. On the other hand the CEC of the ashes showed relation with the particle size distribution and with the external surface area. Leaching and solubilization tests of CCBs showed that FA sample was considered hazardous and classified as class I waste, while CA and BA samples were considered non-hazardous and non-inert wastes and classified as class II-A. FA sample from Figueira power plant must be discarded only after treatment or a stringent disposal criterion must be followed to avoid contamination on site. In this work, feed coal sample was also compared to the CCBs samples generated from it. The results showed the differences between fuel and products through the different characterization techniques. In addition to contributing to the understanding of the relationship between coal and its combustion products, this work can also help to reduce the environmental impacts caused by the CCBs disposal, as well as can also be used to compare the characteristics of CCBs from FTPP with the new wastes that will be generated by the same thermal power plant that will be soon modernized.
High-purity zeolites A were synthesized from different coal combustion by-products (baghouse filter fly ash, cyclone filter ash, and bottom ash) and characterized in terms of morphology, chemical, and mineralogical composition. The products were tested for carbon dioxide capture by using a continuous CO 2 flow system passing through a column packed with the adsorbent material, which was connected to an analyser that directly measures the concentration of CO 2. The values of CO 2 adsorption capacities calculated for the unmodified Na-A zeolites (ZABF, ZACF, and ZABA) were 556.48, 494.29 and 654.82 mg g-1 , respectively. These values were higher than those achieved by the calcium-modified zeolite samples. ZABA adsorbent presented the best performance in CO 2 capture when compared to the other adsorbent material and achieved an adsorption capacity 32% higher than a 4A commercial zeolite. In the adsorption cycles study, the percentage of CO 2 desorption by ZABA at the second and third cycles reached 93%, showing that zeolite A can be regenerated by heating at 150 ºC. The use of coal ashes to obtain zeolites and the application of these products for the CO 2 adsorption can be an important strategy to mitigate both the problem of waste management and the greenhouse gases emission in coal-fired power plants.
Desenvolvimento de material zeolitico de alta pureza a partir de cinzas de carvão para aplicação na captura de dioxido de carbono DAVI HOMEM DE MELLO CASTANHO Dissertação apresentada como parte dos requisitos para obtenção do Grau de Mestre em Ciências na Área de Tecnologia Nuclear -Materiais Orientador: Profa. Dra. Denise Alves Fungaro Versão Original São Paulo 2019 DEDICATÓRIA Dedico este trabalho a todas as pessoas que conheci ao longo desta jornada, as pessoas que acreditaram em mim, as que me motivaram, as que me ensinaram e as que me ajudaram e contribuíram para minha formação como ser humano, a seguir: Aos meus pais, Carlos e Sonia, por me acompanhar, orientar, fortalecer, ensinar, formar, e pela liberdade que sempre me deram, por todos os bons momentos que tivemos. À minha linda, cativante, forte e dedicada amada Josiane pelo carinho, respeito, comprometimento, compreensão, incentivo e amor.Aos meus amigos pelos momentos felizes e de superação juntos.AGRADECIMENTOS À Dra. Denise Alves Fungaro por toda orientação ao longo deste mestrado. À banca examinadora.
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