Araújo, Renata MendonçaPaula, Sueilha Ferreira de Andrade de2023-04-192023-04-192023-01-30PAULA, Sueilha Ferreira de Andrade de. Avaliação por Pirólise de biomassas de Spirulina platensis obtidas em cultivos autotrófico e mixotrófico. Orientador: Renata Mendonça Araújo. 2023. 123f. Tese (Doutorado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2023.https://repositorio.ufrn.br/handle/123456789/52205Microalgae are autotrophic and CO2 fixing microorganisms that have great biotechnological potential and can be used in the production of biofuels in a sustainable way. The high cost of producing microalgae biomass makes large-scale applications unfeasible. Studies indicate that mixotrophic crops can be a strategy capable of reducing the cost of production and achieving economic and environmental sustainability. The biomass used in this work was provided by Pereira et al., 2019 who cultivated the cyanobacteria S. platensis in autotrophic conditions (A) in Zarrouk medium and in mixotrophic conditions with the addition of whey from the production of buffalo mozzarella cheese in different concentrations, 2.5 (M2.5), 5.0 (M5) and 10.0% (M10). In the present study, energy characterizations of biomasses, thermogravimetric analyzes (TGA) and fast micropyrolysis (Py-GC/MS) were carried out at temperatures of 450, 550 and 650 °C in order to evaluate the potential for production of bio- oil and valuable chemicals. Data on the biochemical composition of microalgae were different, as the percentage of whey in the cultures increased, there was a decrease in protein synthesis and an increase in carbohydrates. Despite the difference in composition, according to thermogravimetry data, mass losses of all biomasses occurred in a similar way. Evaluating the pyrolysis data, it was observed that the M10 sample had the lowest protein content in its composition and formed a smaller amount of nitrogenous compounds. There was a reduction of 43.8% (450º), 45.6% (550ºC) and 23.8% (650ºC) in the formation of nitrogenous compounds in relation to sample A. In addition, the temperature also showed a considerable effect on the formation of volatile compounds. The highest yields of nitrogenous compounds, phenols and aromatic and non-aromatic hydrocarbons were observed at 650ºC. Oxygenated and N/O-containing compounds decreased with increasing temperature. In this sense, it is observed that mixotrophic cultivation is a good strategy capable of reducing the N content in the biomass and producing a bio-oil with a lower N content. However, for applications such as biofuels, it is necessary to upgrade these oils.Acesso AbertoQuímicaMixotróficoSpirulina platensisBiomassaCompostos voláteisPirólisedoctoralThesisCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA