https://repositorio.ufu.br/handle/123456789/19618 2026-04-06T19:04:41Z https://repositorio.ufu.br/handle/123456789/48559 Title: Análise técnica e de viabilidade de um processo de pirólise por microondas Abstract: This study investigated the pyrolysis processes of the jatobá fruit peel. First was made the proximate analysis of biomass; from the proximate analysis results, the moisture, ash, volatile matter, and fixed carbon content were determined. From these values, the elemental composition of the jatobá fruit peel was determined using the Parikh, Shen, and Nhuchhen methodologies, in addition to the arithmetic mean of the three methodologies. From the elemental composition and characterization of the jatobá fruit peel, the atomic classification of the jatobá fruit peel was performed, and the atomic ratio was calculated using the van Krevelen diagram. The moisture content was 8.67% ± 0.09%, the ash content was 1.52% ± 0.01% on a dry basis, the volatile content was 80.71% ± 2.63% on a dry basis, and the fixed carbon fraction was 17.77% ± 2.63%. From the average of the three methodologies, it was possible to determine that the carbon content was 48.27% ± 0.46%, the hydrogen content was 5.91% ± 0.01%, and the oxygen content was 43.86% ± 0.34%. From the micropyrolysis tests, it was observed that alkaline catalysts such as potassium hydroxide and calcium oxide presented the best results, since these compounds favored the formation of hydrocarbons, which was explained by the high hydrocarbon content in the volatiles. Tests conducted with calcium oxide at 650 °C showed a hydrocarbon content in the volatiles of 15.0%, while tests conducted at 650 °C using potassium hydroxide showed a hydrocarbon content in the volatiles of 17.1%. It was also observed that the absence of higher temperatures favors hydrocarbon formation. Experiments involving microwave-assisted pyrolysis were performed using particles with diameters between 0.250 mm and 0.355 mm and particles with diameters between 0.106 mm and 0.180 mm; larger particles favored charcoal formation, while smaller particles favored bio-oil formation. Long duration experiments and temperatures between 550 °C and 620 °C are favorable to produce bio-oil. While temperatures between 451 °C and 550 °C are favorable for producing charcoal. Scanning electron microscopy images showed that the charcoal is much more porous and has a more irregular surface than the original biomass, indicating a larger surface area compared to the original biomass. 2026-03-16T00:00:00Z https://repositorio.ufu.br/handle/123456789/48287 Title: Metodologia integrada para cálculo de emissões por fonte energética: aplicação no setor agroindustrial 2025-09-30T00:00:00Z https://repositorio.ufu.br/handle/123456789/48218 Title: Síntese de Fischer-Tropsch: um estudo sobre o hidroprocessamento, rotas convencionais e híbridas Abstract: The transition towards a more sustainable energy matrix and the pursuit of energy security are driving the development of alternative routes for liquid fuel production. In this context, Fischer-Tropsch Synthesis (FTS) stands out as a versatile technology capable of converting synthesis gas (CO + H₂), derived from sources such as natural gas, biomass, or coal, into a wide range of hydrocarbons. However, the primary products of FTS, mainly linear paraffins and high-molecular-weight waxes, do not directly meet the specifications for commercial fuels, primarily due to their inadequate cold flow properties. This work presents a literature review on hydroprocessing as the indispensable technological step for the upgrading of these products. It covers the fundamental reactions of hydrocracking, which adjusts the molecular weight of waxes by converting them into diesel and kerosene fractions, and hydroisomerization, which modifies the molecular structure of linear paraffins into branched isomers, drastically improving their cold flow properties. The key to controlling these reactions is the bifunctional catalyst, whose synergy between a metallic function (usually Pt or Pd) and an acid function (typically shape-selective zeolites) determines the selectivity and yield of the final products. The review demonstrates that the integration of FTS with hydroprocessing results in premium-quality "drop-in" fuels, such as diesel with a very high cetane number and Sustainable Aviation Fuel (SAF), both of which are sulfur-free and burn cleaner than their fossil-based equivalents. Additionally, hydroprocessing is discussed as a flexible technological platform, also fundamental to other advanced biofuel routes, such as HEFA. It is concluded that mastering hydroprocessing is crucial to enabling the production of synthetic and advanced fuels, playing a central role in decarbonization, especially in the aviation sector. 2025-09-19T00:00:00Z https://repositorio.ufu.br/handle/123456789/47745 Title: Análise comparativa entre métodos convencionais e avançados na extração de óleos essenciais de frutas cítricas 2025-09-23T00:00:00Z