Navegando por CNPq "CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA::TECNOLOGIA QUIMICA::PRODUTOS NATURAIS"

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Acesso aberto (Open Access)
Análise experimental do processo de secagem de urucum (Bixa orellana L.) em leito fixo
(Universidade Estadual de Campinas, 1998-12-18) FARIA, Lênio José Guerreiro de; ROCHA, Sandra Cristina dos Santos; http://lattes.cnpq.br/3173533801776868
The drying of annatto seeds (Bixa orellana L.), type Red Piave, was studied in a fixed bed dryer. The optimal conditions were obtained to minimize the bixin losses and to obtain the final moisture content of seeds in the adequate lovels for conservation and quality maintenance. The bixix and the final moisture contents were studied as a function of the operational variables of the drying process. The termodynamic behavior of the seeds during the process of moisture desorption was verified by the static gravimetric method, using saturated salt solutions to maintain atmospheres with relative humidities in the range from 7 to 75%, at temperatures between 15 and 80ºC. GAB medel was used to fit the experimental data and the three parameters of GAB equation were evaluated. The Clausisus-Clapeyron equations was applied to obtain the net isosteric heats of sorption, using the desorption isotherm¿s data. It was verified that the annatto seeds can be conserved with higher stability in atmospheres with relative humidity of 60% in the range of temperatures studied. The quantification of the influences of the inlet variables of the process in the final moisture and bixin contents of the seeds and the identification of the optimal point for the process was accomplished by techniques of fractional factorial design, response surface methodology, canonical analysis and desirability function. Its was verified that the final moisture content of the seeds can be estimated by a second order polynomial model as a function of the is temperature and mass flow rate and of the dryng time, and that final bixin content is significantly influenced only by the process time, being described appropriately by linear model.
Acesso aberto (Open Access)
Estudo do processo de craqueamento térmico catalítico do sebo bovino para produção de biocombustível
(Universidade Federal do Pará, 2017-12-01) PEREIRA, Anderson Mathias; SANTOS, Marcelo Costa; http://lattes.cnpq.br/8380189608965320; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
This work aims to study the use of beef tallow as raw material for the production of bio fuel through the process of catalytic thermal cracking reaction. Three catalytic thermal cracking experiments were carried out in a 143 liters reactor, operating in discontinuous mode at 450 °C at atmospheric pressure, using sodium carbonate (Na2CO3) as the catalyst. Two experiments were carried out with crude beef tallow (5 and 10 % Na2CO3 - mass/mass) and one with bovine tallow soap (5 % Na2CO3 - mass/mass). The organic liquid products obtained from the reactions were analyzed through physicochemical analysis and chemical composition. Fractional distillation was also realized in order to obtain fractions of petrol, kerosene and light diesel similar to petroleum. In order to follow the reactions over time, aliquots were withdrawn every 10 minutes up to a total of 10 samples with the first point collected within 30 minutes of reaction. For the collected samples physicochemical analysis and identification of the chemical compounds were realized. The results showed a tendency to obtain higher yields in organic liquid product (OLP) using the catalyst in larger quantities with the crude sample. The chemical identification showed the amount of hydrocarbons present (paraffins and olefins) ranging from 89.28 to 92.23 % and oxygenates (ketones) from 7.77 to 10.72 %. After the distillations, a predominance was observed in the diesel fraction (235-305 °C) while the petrol and kerosene fractions were lower, this behavior was repeated in all experiments. Regarding the samples collected over the time of the reactions it is possible to verify an increase in the acidity index and formation of oxygenates up to 60/70 minutes indicating the occurrence of the primary cracking and then, until the end of the reaction, a decrease in these values evidencing the secondary cracking.
Acesso aberto (Open Access)
Extração, estabilidade, reologia e higroscopicidade do corante de pitaya (Hylocereus costaricencis)
(Universidade Federal do Pará, 2015-03-04) SOUSA, Erika Milene Pinto de; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173
With the advancement of new technologies the natural dyes market is expanding with the purpose to replace the artificial dyes, harmful to health. Natural dyes from fruit, give the product a more natural appearance, opposed what occur with synthetic tones. In this context, perform out extraction of dragon fruit dye contained in the fruit pulp, by immersion in distilled water, then makes up the physical and physico-chemical characterization of pulp, the study of the stability at light and temperature of concentration from betacyanin and dye color, quantifying the betacyanin content by UV spectrophotometry and color by colorimetric tristimulus using the CIE L * a * b *. Also evaluates up the rheological behavior of pulp pitaya diluted in distilled water at a ratio of 1: 1 by means of mathematical models with the support of ReoWin and Statistica 7.0 program. Finally, the study it’s made a hygroscopicity study obtained by freeze-drying at different concentrations maltodextrin, also analyzing the pure dye by verifying through of sorption curves optimal storage conditions for dragon fruit dye.