Navegando por CNPq "CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA::TECNOLOGIA QUIMICA::OLEOS"

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Acesso aberto (Open Access)
Extração do óleo de tucumã-do-Pará (Astrocaryum vulgare) usando CO2 supercrítico visando o aumento de escala
(Universidade Federal do Pará, 2022-04-04) MENEZES, Eduardo Gama Ortiz; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
With the growing worldwide demand for products and wealth generation, there is a need to invest in new sustainable processes and engineering practices for scale expansion. Thus, the objective of this work was to obtain β-carotene-rich tucumã-do-Pará (Astrocaryum vulgare) oil using supercritical CO2 and to verify the adequacy of two new scale-up equations. Therefore, two isotherms and three pressures (40°C, 60°C, 150bar, 250bar, 400bar) were used. In the condition that presented the highest oil and β-carotene extraction yield, a kinetic study was carried out, followed by the application of a new equation based on Buckingham's π theorem. The highest oil extraction yield (31.49±0.04%) was obtained at 60°C and 400bar with a high concentration of oleic acid, and this yield was similar to the value obtained by soxhlet, which was 32.73±0, 59% oil. The application of the Tukey test (p <0.05) shows that there is no significant difference between the extraction yield obtained in the isotherm of 40 °C and 60 °C in the pressure condition of 400bar. The highest concentration of β-carotene (1351.8±0.02 μg/g) was obtained at 40°C and 400bar, and the solvent density was considered the most significant variable with the greatest influence on β-carotene extraction. The kinetic study carried out with the application of a new mathematical proposal based on the correlation between operational variables (solvent flow, feed mass, height and diameter of the extraction bed), mass transfer mechanism and constancy of the inclination angle of the kinetic curves that , for a solvent flow rate of 10.93 g/min, on the larger scale, the diffusive step controlled the mass transfer mechanism.
Acesso aberto (Open Access)
Extração e transesterificação do óleo de resíduo industrial de palmiste usando metanol supercrítico
(Universidade Federal do Pará, 2018-11-23) COSTA, Wanessa Almeida da; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
Palm kernel is an oleaginous seed found in fruits of Elaeis guineensis Jacq. and which represents one of the main oils consumed in the world, with an mean production of 18,59 million tons. Its main process is the extraction by mechanical pressing that generates, in the world, approximately 9.6 x 109 tons of residue also called residual cake. Since this residue can still present about 12% of remaining oil, supercritical fluid extraction (SFE) is presented as an alternative to the recovery of this oil. Soxhlet extraction was also performed to be compared to the SFE. Pressures of 150, 250 and 350 bar and temperatures of 40, 60 and 80 °C were used in the experiments. The raw material was characterized before and after the SFE by moisture, ash, fibers, proteins and lipids contents and the extracts were characterized by gas chromatography/mass spectrometry (GC/MS). The kinetic data were compared to the Sovová (2012) model and the condition of highest yield was used in the transesterification experiments. Molar ratios of 1:24 and 1:42 (oil: methanol), temperatures of 250, 300 and 350 °C, constant pressure of 200 bar and reaction times of 5, 10, 15, 20 and 25 minutes were used. The products were also analyzed by GC/MS to verify the transformation of triacylglycerols into methyl esters. The main results of this study were: SFE does not alter the centesimal composition of the raw material; the condition of highest yield was 350 bar and 80 °C; Sovová's model had the best fit to the kinetic data; the condition 1:42, 350 ºC was the one that obtained the highest content of esters (99.81%) in only 5 minutes of reaction. The transesterification of palm kernel oil in a supercritical medium is a valid alternative and presents advantages over the conventional method, however a more in-depth analysis considering the technical and economic limitations of this method is necessary.
Acesso aberto (Open Access)
Produção de biodiesel através da hidroesterificação do óleo de andiroba (Carapa guianensis, Aubl.) via Catalise Heterogenea Acida
(Universidade Federal do Pará, 2011-06-30) TEIXEIRA, Evilácio Luz; SOUZA, Mariana de Mattos Vieira Mello; http://lattes.cnpq.br/8882084525542926; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172
The process of hidroesterification (hydrolysis followed by esterification) is constituted as an alternative to the conventional process for producing biodiesel, because it allows the use of raw materials of any content of fatty acids and moisture. Biodiesel is derived from the esterification of Andiroba oil with high content of fatty acids being used niobium oxide powder (HY-340) from Brazilian Company of Metallurgy and Mining - CBMM – as a catalyst. For the execution of experiments was used an autoclave reactor (batch). The hydrolysis reaction was conducted at 300oC, 1200 psi and molar ratio water/oil equal 20. In the esterification reactions were observed the effects of molar ratio methanol/fatty acid (1,2; 2,1 an 3,0), temperature (150, 175 and 200oC) and the concentration of catalyst (0, 10 and 20%) on conversion and initial rate of reaction. The data were conducted according to experimental design (factorial with 23 and adding 3 plants points) analyzed by the program Statistica. The conversion of esterification reaction was monitored from measurements of titrimetric acidity of aliquots removed at times of 5, 10, 15, 20, 25, 30, 45 and 60 minutes. In the experiments of esterification the highest conversion obtained was 96.1% with temperature of 200 o C, 20% m / m of catalyst and molar ratio methanol / acid equal to 3.0. Eliminating the catalyst and recital the same levels for the other two analyzed variables (temperature and molar ratio), was obtained a conversion of 95.3%, however was observed a conversion rate child, taking-if an increase of 35 minutes in the time of compared with the reaction catalyzed reaction.