Engenharia Química

URI Permanente desta comunidade

http://repositorio.ufes.br/handle/10/17472
Programa de Pós-Graduação em Engenharia Química

Centro: CCAE
Telefone: (28) 3552 8719
URL do programa: http://www.engenhariaquimica.alegre.ufes.br/pos-graduacao/PPEQ

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Navegando Engenharia Química por Autor "Alves, Rejane Costa"

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    Análise da cinética de decomposição térmica da casca de urucum (bixa orellana l.)
    (Universidade Federal do Espírito Santo, 2024-05-28) Breciani, João Guilherme Fraga; Sousa, Robson Costa de; Costa, Ariany Binda Silva; https://orcid.org/0000-0001-7320-3317; https://orcid.org/; http://lattes.cnpq.br/; Carvalho, Romero Florentino de; https://orcid.org/; http://lattes.cnpq.br/; Alves, Rejane Costa; https://orcid.org/; http://lattes.cnpq.br/; Perazzini, Maisa Tonon Bitti
    This study aims to investigate the drying kinetics and thermal decomposition of annatto husks (Bixa orellana L.) in a nitrogen atmosphere. The analysis was performed through physical-chemical, thermal, and thermodynamic characterizations of the residue. Based the data obtained from the physico-chemical characterization, the residue's energy potential was verified, showing a low ash content and high calorific value. The thermal characterization was carried out using thermogravimetric analysis of the residues at different heating rates, which allowed for the determination of the material's peak, ignition, and burnout temperatures during the pyrolysis process. From this data, a drying kinetics study was performed, where the Page model provided the best fit to the experimental data. Additionally, the thermal decomposition kinetics of the material was studied using global and multicomponent models. Among the global models, Friedman, FWO, KAS, and Vyazovkin models were analyzed, but none were suitable for experimental representation. For the multicomponent models, consecutive reactions and independent parallel reactions were analyzed, both showing excellent fits, with TG deviations below 2.6% for all heating rates analyzed. Finally, in the thermodynamic characterization, the values of enthalpy, Gibbs free energy, and entropy indicate that the thermal decomposition of annatto husks in a nitrogen atmosphere is an endothermic and non-spontaneous process.
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    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