Navegando por Assunto "Desorption"

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Acesso aberto (Open Access)
Análise experimental do processo de extração do óleo essencial de Puxuri [Licaria puchury-major (Mart.), Kosterm., Lauraceae] por arraste com vapor
(Universidade Federal do Pará, 2014-04-30) MAFRA, Eduardo de Souza; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173
Analyse experimentally the extraction process of the essential oil of seeds and aerial parts of puxuri for drag with steam. The puxuri, [Licaria puchury-major (Mart.)] Kosterm., Lauraceae], is a species of the Amazon forest with great potential for the Bioproducts Industry (pharmaceu-ticals, cosmetics, food and natural pesticide) due to the presence of safrole in its essential oil. This work is an anatomical study and physical and chemical characterization of plant parts used for oil extraction. Studying the kinetics of drying of seeds, thin branches and leaves of puxuri and quantifies the influence of convective drying in fixed bed in safrole content and moisture content. Through statistically designed experiments, identify levels of process variables: mois-ture content, particle size and extraction time of samples of seed of puxuri, that optimize both answers the responses: in essential oil yield and content of safrole, its major component, within the experimental domain adopted and 90% confidence (α = 0.10) in the extraction process of the essential oil by steam drag. Chemically analyzed the essential oil of puxuri by GC-MS and iden-tifies the chemical composition in terms of their senior constituents. Using the gravimetric ap-proximation method static with concentrated solutions, desorption isotherms are obtained for puxuri seeds powder, in temperatures 15, 25 and 35ºC. The experimental data hygroscopic equi-librium, fits very well the GAB model, being estimated the heats of sorption liquid and inte-grals, in addition to the equilibrium moisture content in monolayer and other constants in the equation. Noted low toxicity of essential oil of puxuri and the solid residue of extraction can be used as material for the production of saponifiable transparent soaps to cold.
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/5698208558551065
In 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.