Programa de Pós-Graduação em Engenharia Química - PPGEQ/ITEC
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2308
O Programa de Pós-Graduação em Engenharia Química (PPGEQ) do Insituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA). Sendo aprovado pela CAPES / MEC em 1991, foi oficialmente iniciado em março de 1992.
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Item Acesso aberto (Open Access) Desacidificação de frações destiladas de produto líquido orgânico do craqueamento termo-catalítico de óleos vegetais via adsorção em y-alumina e lama vermelha ativada(Universidade Federal do Pará, 2015-04-16) COSTA, Karen Marcela Barros da; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065This paper studied the adsorption of residual free fatty acids (carboxylic acids) present in distilled fractions from the Liquid Organic Product (PLO) obtained by thermal catalytic cracking of vegetable oil. The objective was to deacidification of distilled fractions obtained from the distillation of the PLO. The experiments were performed using different distilled fractions using three different adsorbents, y-Alumina, Red Mud Thermally activated (400 °C) and Red mud chemically activated with solutions of HCl in different concentrations (0.25, 1 and 2M). The adsorbent capacity relative to adsorption of free fatty acids was evaluated by means of kinetic studies, measuring the change in concentration of free fatty acids present before and after adsorption by determining the Acid Number. The results indicated that increasing the initial concentration of acids decreases the adsorption capacity of the adsorbent, showing that the process is less effective at higher concentrations. For experiments with different percentages of adsorbents seen that when using 0.5% adsorbent to obtain greater efficiency in the removal of fatty acids, which decreases with increasing percentage of adsorbent. The most efficient adsorbent was red mud activated with 1M HCl, which was obtained a reduction of 98% of the fatty acids to a sample with an initial acid number of 4 mg KOH/g. Mathematical modeling indicated that the kinetic model that best represents the process was the Pseudo Second- Order. Therefore, the results show that the adsorbents used are mostly effective in the removal of free fatty acids and the initial concentration of acids in the sample has a direct effect on the performance of adsorption thereof.Item Acesso aberto (Open Access) Estudo cinético e das isotermas de adsorção dos óleos de palma (Elaes guineensis, Jacq.) e andiroba (Carapa guianensis, Aubl.) em y-alumina e modelagem da dessorção com dióxido de carbono supercrítico(Universidade Federal do Pará, 2013-11-08) AMARAL, Anderson Rocha; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065In this work, the variables of the batch adsorption process of palm (Elaeis guineensis, Jacq.) and andiroba (Carapa guianensis, Aubl.) vegetables oils on thermally activated alumina at 723,15 K and 923,15 K (y-alumina) has been investigated by analyzing the influence of temperature, time, mass of vegetable oil, mass of adsorbent on the adsorbent capacity. A kinetic model of second-order was proposed to modeling the adsorption capacity of free fatty acids (FFA). Capacity results of FFA of the crude palm oil on y-alumina AG.450 at 328.15 K and of the crude andiroba oil on y-alumina AG.650 at 323.15 K were obtained from the consecutive adsorption experiments and adjusted by isotherms of Langmuir e BET. The transfer mass model of TAN & LIOU (1989) was used to modeling the kinetic desorption of the palm oil from y-alumina AG.650 and of the andiroba oil on y-alumina AG.450 with supercritical carbon dioxide, evaluating the yields, errors, correlation coefficients and the residues of the desorbed oil mass versus predicted by the model.The study of the variables influence, over the adsorption capacity, presented negative correlation (with exponential behavior) to the variable mass of oil. The adsorbent mass influence, presented a positive correlation (with a linear behavior) and the temperature increase is favorable to the adsorption process. The total reduction of the FFA after three consecutive adsorptions of the crude palm oil on y-alumina AG.450 and after four consecutive adsorptions on -alumina AG.650 with andiroba oil, were 21.07 % and 40.29 %, respectively. The modeling of the FFA capacity to the palm oil with Langmuir model, presented a high experimental data prediction ability (R² = 0.9610), as well as to the andiroba oil with the BET model, which presented a high adjustment (R² = 0.9140). Tan & Liou model evidenced high prediction capacity of the desorption oil mass from γ-alumina for all experiments, minimum correlation coefficient of 0.9230 and magnitude residues of 10-1 grams. The yields, based on adsorbate initial mass, of the palm oil desorbed from y-alumina AG.650 at 20 MPa up to 30 MPa and 323.15 K up to 328.15 K were 28.880 % up to 34.563 %, while to the andiroba oil on y-alumina AG.450 at 15 MPa up to 25 MPa at 323.15 K were 14.108 % up to 27.972 %. The yields results shows that the increase of pressure and temperature are favorable to the supercritical desorption.Item Acesso aberto (Open Access) Extratos de sementes de gergelim preto (Sesamum indicum L) obtidos via CO2 supercrítico: isotermas de rendimento global, dados cinéticos e ajustes, ácidos graxos totais, fitosteróis e efeitos neuroprotetores(Universidade Federal do Pará, 2013-12-17) BOTELHO, José Rafael Santos; ARAUJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748In Brazilian folk medicine, black sesame (Sesamum indicum L) seeds is one of the most important ingredients present in the tea used to treat encephalic stroke victims. Nevertheless, isolation of black sesame extracts to medicinal finality using supercritical fluid technology has not been performed. The objective of this work was to investigate some process variables of supercritical fluid extraction in black sesame to generate extracts applicable in stroke research. Two isothermal (40 and 60 °C) were explored, combined with pressures that ranged from 200-400 bar, at a constant CO2 mass flow rate of 5,9 x 10-5 kg/s. The global yields ranged from 37-53% in dry basis. The highest mass yield was obtained at 60 °C and 400 bar. The fatty acid composition comprised a high unsaturated/saturated ratio. Chromatographic analysis of phytosterol content in the high global yield extract revealed higher amounts of β-sitosterol + sitostanol, cholesterol, campesterol + campestanol + 24-methylene cholesterol, Δ-5 avenasterol and stigmasterol, while lower levels of Δ-5,24 stigmastadienol, brassicasterol, clerosterol + Δ-5-23 stigmastadienol, Δ-7 avenasterol, eritrodiol and Δ-7 stigmastenol were present in the black sesame extract. Overall extraction curves from the supercritical fluid extraction in lower and higher global yields (200 e 400 bar at 60 °C) fitted the Tan and Liou (1989), Martinez et al. (2003), Esquível et al. (1999), Goto et al. (1993) e Sovová models (1994 and 2012). The models of Tan and Liou (1989), Goto et al. (1993) and Sovová (1994 and 2012) presented the best residual sum of squares values. Pilot experiments suggest that black sesame extract is neuroprotective following endothelin-1 induced focal ischemia into the motor cortex of male adult rat, observing indications that a prejudicial cell form for the stroke`s status was inhibited by the treatment.Item Acesso aberto (Open Access) Obtenção de gordura das sementes de Ucuúba (Virola surinamensis) por meio de extração com CO2 em estado supercrítico: rendimento global, dados cinéticos, ácidos graxos totais e atividade antimicrobiana(Universidade Federal do Pará, 2015-09-28) CORDEIRO, Renato Macedo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748The Virola surinamensis, popularly known as ucuúba, is a typical tree found in floodplain habitats and along rivers in the Amazon region. The fat extracted from the seeds has a high melting point and is a product appreciated by the cosmetic industry. The objective of this work was to study the extraction of ucuúba seed fat using supercritical fluid and compare, in terms of process yield and composition of the extracts, with those obtained from the organic solvent extraction technique (via soxhlet). The extraction technique Supercritical Fluid Extraction (SFE) was used because it is regarded as a clean technology, economically attractive, and environmentally safe, avoiding the consumption of large amounts of organic solvents, which are often expensive and potentially harmful. The supercritical extracts of ucuúba seeds were obtained at temperatures of 40, 60 and 80 °C, combined with a pressure of 350 bar, the solvent density varied between 789.2 and 935.6 kg / m3, and a flow of 2.7 L / min. The highest yield obtained using supercritical CO2 was 64.39% for the extraction condition of 350 bar and 80 °C. The yield for the extraction via soxhlet was 61.38%. The mass transfer models of Goto et al. (1993), Esquivel et al. (1999), Tan and Lio (1989), Barton (1991) and Martinez et al. (2003) were employed to describe the extraction kinetics using supercritical fluid. The models that best described the extraction kinetics, with low average deviations, were the models of Martinez et al. (2003) and Goto et al. (1991). The fatty acid profile analysis showed that the ucuúba fat is composed predominantly of saturated fatty acids, mainly of myristic and lauric acids. The antimicrobial activity of the fats obtained was tested on the following organisms: Candida albicans, Staphylococcus aureus and Escherichia coli. Only the bacterium Staphylococcus aureus showed zone of inhibition, ranging from 10 to 11 mm.