Valter José Fernandes Junior
Federal University of Rio Grande do Norte
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Featured researches published by Valter José Fernandes Junior.
Química Nova | 2012
Luzia P. F. C. Galvão; Marcela N. Barbosa; Antonio S. Araujo; Valter José Fernandes Junior; Anne Gabriela Dias Santos; Geraldo E. Luz
Iodide potassium incorporated on mesoporous molecular sieves (SBA-15 and MCM-41) was used as heterogeneous catalysts in the transesterification of sunflower oil under different conditions of reaction time and ratio catalyst/oil (w/w). The results have showed that the system supported in SBA-15 has been more active than the supported in MCM-41, promoting a conversion to methyl esters of 84.98%.
Química Nova | 2012
Valter José Fernandes Junior; Antônio de S. Araújo; Fábio da Silva Vinhado; Paulo Roberto Pivesso
The nature of the solid residue formed in beef tallow biodiesel from two commercial producers in Brazil was determined by comparative analytical techniques, namely, gas chromatography with flame ionization detector (GC-FID) and thermogravimetry (TG). Pure monopalmitin and monostearin were used as reference standards for both methodologies. Analyses were carried out before and after filtration of the solids formed, which allowed the observation that the formation of precipitate reduced the levels of monoglycerides in the beef tallow biodiesel. The chromatographic and thermogravimetric results confirmed the nature of the residue as saturated monoglycerides, predominantly monostearin and monopalmitin.
Petroleum Science and Technology | 2017
Larissa Cicianny Luz Ferreira de Araújo; Taisa Cristine de Moura Dantas; Aruzza Mabel de Morais Araújo; Amanda Duarte Gondim; Valter José Fernandes Junior; Antonio S. Araujo
ABSTRACT In research for materials that can be applied in processing heavy oil (petroleum), this work proposes to synthesize mesoporous heterogeneous catalysts, type SBA-15, with the addition of cerium metal and aluminum. These catalysts were characterized by X-ray diffraction, scanning electron micrographs coupled to energy dispersive spectrometry, spectroscopy in the infrared region by Fourier transform, N2 adsorption and desorption and thermal analysis-thermogravimetry. Thermal tests were performed to evaluate the thermal and catalytic degradation process with a sample of heavy oil (°API = 14). Through the non-isothermal kinetic model of Ozawa Flynn Wall (OFW) some parameters for determining the apparent activation energy of decomposition were obtained. The petroleum with 12% of Ce5Al50SBA-15 showed a catalytic activity for this material. It has been seen that there was a decrease in the Ea in model free of the order from 89.0 to 104.9 kJ mol−1 in α = 50% ± 10%, and it was repeated from the first percentage until the last showing performance of Ce5Al50SBA-15 as a catalyst.
Revista Virtual de Química | 2015
Aneliése Lunguinho Figueiredo; Ana Paula de Melo Alves; Valter José Fernandes Junior; Antonio S. Araujo
Plastics have been an indispensable material in the life of humanity. However, these polymers have a slow degradation process that can lead to contamination of soil, air and water when they are not properly allocated. Since the poly (ethylene terephthalate) PET is one of the most commonly consumed thermoplastic resins in Brazil and with a short time of use, it is normal to find it being discarded in landfills, streets, lakes and garbage dumps. Consequently, the recycling of plastic waste is an alternative for avoiding environmental and social problems. In this paper we describe the recycling methods for reuse of plastic waste, mainly the tertiary recycling of PET using the pyrolysis process. Tertiary recycling pyrolysis – of PET is important because it reduces costs of pre-treatment, collection and selection, and allows the obtaining of both a combustible substance and chemicals used for the obtaining of the polymer which gave it origin or even a new polymer, thus eliminating the risk of using recycled PET for packaging foods, beverages and pharmaceuticals.
Journal of Thermal Analysis and Calorimetry | 2011
Luzia P. F. C. Galvão; Anne G. D. Santos; Amanda Duarte Gondim; Marcela N. Barbosa; Antonio S. Araujo; Luiz Di Souza; Valter José Fernandes Junior
Revista Virtual de Química | 2015
Aneliése Lunguinho Figueiredo; Ana P. M. Alves; Valter José Fernandes Junior; Antonio S. Araujo
Thermochimica Acta | 2018
Danielle de OliveiraMaia; Alanna Martinna de SouzaChagas; Aruzza Mabel de Morais Araújo; Antonio Vicente de Mendonça Júnior; Isabelle Mariane de Lima Ferreira; Francisco das Chagas Dantas de Lemos; Antonio S. Araujo; Valter José Fernandes Junior; Amanda Duarte Gondim
UNOPAR Científica Ciências Exatas e Tecnológicas | 2015
Marcílio dos Santos Tavares; Thiago Chellappa; Antonio S. Araujo; Valter José Fernandes Junior
Archive | 2014
Amanda Duarte Gondim; Patrícia F. Carvalho Galvão; Raul Rosenhaim; Valter José Fernandes Junior
Anais do Congresso Brasileiro de Engenharia Química | 2014
Aruzza Mabel de Morais Araújo; Antonio S. Araujo; Valter José Fernandes Junior; Luiz Di Souza
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Ana Catarina Fernandes Coriolano
Federal University of Rio Grande do Norte
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