Mestrado em Engenharia Química

URI Permanente para esta coleção

http://repositorio.ufes.br/handle/10/17473

Nível: Mestrado Acadêmico
Ano de início: 2014
Conceito atual na CAPES: 3
Ato normativo: Homologado no Parecer CES/CNE nº 487/2018, da Câmara de Educação Superior do Conselho Nacional de Educação, e no Parecer nº 00049/2019/CONJURMEC/CGU/AGU, da Consultoria Jurídica junto ao Ministério da Educação, proferidos nos autos do Processo nº 23001.000335/2018-51. Divulgado na portaria 609 (14/03/2019) e publicada no DOU (18/03/2019- Edição 52/Seção 1/pg 63).
Periodicidade de seleção: Semestral
Área(s) de concentração: Engenharia Química
Url do curso: https://engenhariaquimica.alegre.ufes.br/pt-br/pos-graduacao/PPEQ/detalhes-do-curso?id=1077

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Agora exibindo 1 - 5 de 70

Síntese do biodiesel de óleo de soja utilizando óxido de cálcio oriundo da concha de sururu impregnado com íon itérbio (3+)
(Universidade Federal do Espírito Santo, 2024-07-25) Gomes, Mirian Alves; Guimarães, Damaris; https://orcid.org/0000-0002-4932-3252; http://lattes.cnpq.br/6576377621734943; Barañano, Audrei Giménez; https://orcid.org/0000-0002-0174-5202; http://lattes.cnpq.br/6155024776819193; https://orcid.org/0009-0004-4358-8673; http://lattes.cnpq.br/7254607078386975 ; Altoé, Mario Alberto Simonato; https://orcid.org/0009-0004-6226-7912; http://lattes.cnpq.br/8481776828705621 ; Souza, Murilo de Oliveira; https://orcid.org/0000-0002-5299-564X; http://lattes.cnpq.br/1832643912229312
The synthesis of biodiesel is carried out through transesterification reaction, using vegetable oils or animal fats, short-chain alcohols, in the presence of basic/acid catalysts, whether heterogeneous or homogeneous. Among heterogeneous catalysts, calcium oxide (CaO) shows promising results. In this study, calcium oxide obtained from sururu shell was impregnated with Yb3+ ions, via coprecipitation method. The catalysts were thermally activated by calcination at 900°C for 4 hours and evaluated for their catalytic potential in methyl biodiesel synthesis using soybean oil. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) were conducted to obtain catalyst characteristics and properties. Biodiesel yield was determined by proton nuclear magnetic resonance (1H NMR) and thin-layer chromatography (TLC). Central composite rotational design (CCRD) was employed to optimize reaction conditions. Results revealed that maximum efficiency was achieved at 80°C, with 5% catalyst and alcohol:oil ratio of 15:1, resulting in 87% conversion for CaO without Yb3+ and 85% for CaO with Yb3+, within just 1 hour. Modified CaO allowed for five cycles of biodiesel synthesis, with a 2.78% reduction in yield in the first catalytic cycle. Conversely, CaO without Yb3+ showed a significantly greater yield reduction, totaling 30.48%. The feasibility of reuse across multiple cycles was attributed to the robustness promoted by oxide impregnation, due to the low solubility of calcium oxide.
Modelagem e predição de propriedades mecânicas e físicas de fibras lignocelulósicas por FTIR via regressão multivariada
(Universidade Federal do Espírito Santo, 2025-08-27) Lauriano, Laiza Andrade; Oliveira, Michel Picanço; https://orcid.org/0000-0001-9241-0194; http://lattes.cnpq.br/6383844066460475; Dutra, Júlio Cesar Sampaio; https://orcid.org/0000-0001-6784-4150; http://lattes.cnpq.br/5331990513570911; https://orcid.org/0009-0008-3199-7380; http://lattes.cnpq.br/4891425138936984; Carreira, Lilian Gasparelli; https://orcid.org/0000-0003-2415-6299; http://lattes.cnpq.br/8151437321864971; Profeti, Luciene Paula Roberto; https://orcid.org/0000-0001-6280-2410; http://lattes.cnpq.br/6517975282316378; Dias, Ana Carolina Spindola Rangel; http://lattes.cnpq.br/2866902801584203
In the face of contemporary challenges, the pursuit of sustainable materials that minimize environmental impact is essential. In this context, this study evaluated the use of lignocel lulosic fibers in composites as an alternative to synthetic materials. Lignocellulosic fibers are notable for their advantageous characteristics, such as biodegradability, low cost, and competitive mechanical performance in specific applications, such as the reinforcement of polymer composites used in automobiles and civil construction. However, determining the mechanical and physical properties of lignocellulosic fibers remains a challenge, primarily due to their microscopic dimensions, heterogeneity, and the complexity of experimental testing. Despite these difficulties, detailed knowledge of these properties is fundamental for the efficient selection and application of fibers in polymer composites. Given this scenario, this dissertation proposes the development of Principal Component Regression (PCR) and Partial Least Squares (PLS) mathematical models to predict physical and mechanical properties from spectral data obtained by Fourier-Transform Infrared (FTIR) Spectroscopy, thereby optimizing the characterization process. The models showed satisfactory performance in explaining the variability of data for diameter, density, and tensile strength, with PLS showing the best results for diameter (R2 = 0,766 e Q2 = 0,811) and density (R2 = 0,874 e Q2 = 0,877), and PCR for tensile strength (R2 = 0,721 e Q2 = 0,722). The results highlight the potential of chemometrics as an auxiliary tool for the selection and application of lignocellulosic fibers in sustainable composites.
Avaliação dos efeitos da modificação térmica nas propriedades de diferentes madeiras
(Universidade Federal do Espírito Santo, 2025-08-01) Dias, Nathália Gabriele Franca; Alves, Rejane Costa; https://orcid.org/0000-0003-4059-3974; http://lattes.cnpq.br/8580447433109486; https://orcid.org/0000-0002-5255-7025; http://lattes.cnpq.br/7055222960818900; Carrasco, Edgar Vladimiro Mantilla; https://orcid.org/0000-0001-7870-0283; http://lattes.cnpq.br/3716965047168777; Dias Júnior, Ananias Francisco; https://orcid.org/0000-0001-9974-0567; http://lattes.cnpq.br/2428652077952117
This study evaluated the effects of thermal modification on the chemical, physical, and mechanical properties of Eucalyptus sp., Pinus sp., and Cedrela sp. woods. The samples were subjected to heat treatments at 140°C, 180°C, 220°C, and 240°C in a reactor system, with a heating rate of 0.3°C/min. Chemical properties were evaluated through FTIR spectroscopy, X-ray diffraction, and thermogravimetric analysis; physical properties were assessed by apparent density, wettability, and colorimetry; and mechanical properties were analyzed through static bending, tension, compression, Janka hardness tests, and wave propagation. The results indicated that heat treatment significantly affects wood properties, varying according to species and temperature. Chemical analyses revealed degradation of hydroxyl groups and modifications in lignin, with a reduction in the crystallinity index. Apparent density decreased in the 220°C and 240°C treatments, especially for eucalyptus and cedar, with significant reduction observed at 140°C for Eucalyptus sp. Wettability progressively decreased with increasing temperature for Eucalyptus sp. and Cedrela sp., while pine showed increased wettability at lower temperatures, followed by reduction at higher temperatures, becoming equivalent to the control. Wood darkening was progressive, with the L* parameter being the most sensitive. Mechanical properties were most affected above 220°C, with the most significant reduction in modulus of rupture, with eucalyptus being the most sensitive species due to the effects of lignin plasticization at lower temperatures. Non-destructive methods showed strong correlation with static tests (R² > 90%). It is concluded that thermal modification is a viable technique to alter specific wood properties, with effects varying according to species and wood treatment temperature
Análise do efeito das propriedades físicas de particulados na fluidodinâmica do leito de jorro cônico
(Universidade Federal do Espírito Santo, 2025-03-21) Castanheira, Vinícius Castilholi; Carvalho, Romero Florentino de ; https://orcid.org/; http://lattes.cnpq.br/8949967345647610; Sousa, Robson Costa de ; https://orcid.org/0000-0002-2353-9098; http://lattes.cnpq.br/7320586055142013; https://orcid.org/0009-0007-2531-9324; http://lattes.cnpq.br/2776582781838015; Guidolini, Icaro Pianca; https://orcid.org/; http://lattes.cnpq.br/6264980481447359; Freire, Fabio Bentes; https://orcid.org/0000-0001-9258-360X; http://lattes.cnpq.br/8937961078558996
The conical spouted bed has important applications in industrial processes such as drying and pyrolysis of biomass, in which they have varied physical characteristics, generating different fluid behaviors In this context, the present study aimed to To analyze the effect of the physical properties of particulate matter on the fluid-dynamic behavior of the conical spouting bed from the analysis of experimental data and the comparison with predictions of parameters obtained by empirical equations and correlations present in the literature. The characterization of the glass spheres, coffee and black pepper beans, annatto seeds, jackfruit, açaí and residue such as orange pomace involved the measurement of apparent densities, actual density, bulk density, bed porosity, diameter, sphericity and roundness. The conical spouting bed used has a total height of 70.0 cm, an internal diameter of 19.0 cm, a cylindrical column with a height of 47.0 cm, and a cone at the bottom of the column with a height of 15 cm with a tilt angle of 60º. The main effects of the physical properties showed that the highest pressure drops (maximum and stable) were influenced by physical characteristics such as density, mainly for glass spheres (2500 kg/m³) and açaí seeds (1366 kg/m³) and jackfruit (1209 kg/m³) in the case of biologic materials. The size of these materials also influenced the fluid dynamics of the bed, especially the minimum spouting velocity. The correlations adjusted with statistical treatment presented more satisfactory results in relation to the correlations found in the literature for the prediction of parameters such as Reynolds minimum spout, maximum pressure drop and stable spout. Finally, the study of fluid-particle interactions with the analyzed materials was carried out in the present work in conical spouted bed. It was possible to notice that materials of lower sphericity presented higher drag coefficients, being greater than drag force exerted by the fluid. By contrast, spherical particles exhibited lower flow resistance, resulting in a reduced drag coefficient. In general, it was possible to observe the real influence of physical properties on fluid dynamic parameters, and the results were consistent with what was observed in the literature
Produção de compósito plástico-madeira a partir de resíduos da indústria madeireira capixaba
(Universidade Federal do Espírito Santo, 2025-02-12) Miranda Júnior, Gilson Mendonça de; Dias, Josinaldo de Oliveira; https://orcid.org/0000-0001-6865-851X ; http://lattes.cnpq.br/1030155171981790; Corrêa, Glaucinei Rodrigues ; https://orcid.org/0000-0002-4311-5444; http://lattes.cnpq.br/9878675593298644; Alves, Rejane Costa; https://orcid.org/0000-0003-4059-3974; http://lattes.cnpq.br/8580447433109486; https://orcid.org/0000-0002-9312-156X; http://lattes.cnpq.br/9786020486733199; Oliveira, Michel Picanço; https://orcid.org/0000-0001-9241-0194; http://lattes.cnpq.br/6383844066460475 ; Carrasco, Edgar Vladimiro Mantilla; https://orcid.org/0000-0001-7870-0283; http://lattes.cnpq.br/3716965047168777
This study investigated the production of wood-plastic composites (WPCs) using Eucalyptus sp. residues (ER) from the Capixaba wood industry and poly(vinyl alcohol) (PVA), aiming to evaluate chemical, structural, physical, and mechanical properties, as well as to optimize sustainable formulations. The composites were produced with different proportions of residue (70%, 60%, and 40%) and PVA (30%, 40%, and 60%), along with two particle sizes (35 and 60 mesh). The results indicated that increasing the ER content enhanced the crystallinity and thermal stability of the composites, while PVA improved the adhesion between components. Composites with higher ER content preserved the structural and thermal characteristics of lignin and cellulose, whereas those with higher PVA content exhibited lower thermal stability. The 60% ER and 40% PVA ratio showed the best balance, combining thermal stability, adhesion, and homogeneity. In the physical analyses, composites with higher PVA content showed greater dimensional stability, despite presenting lower apparent density values. The mechanical results highlighted the composites with 60% ER and 40% PVA (T2 and T5) as the most resistant in tensile, compression, flexural, and impact tests. Particle size significantly influenced adhesion and material uniformity, with the 35 mesh size yielding better results compared to the 60 mesh. These findings demonstrate that WPCs are promising for sustainable applications, adding value to waste materials and contributing to the reduction of environmental impacts

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