Engenharia Química
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/25
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4 resultados
Resultados da Pesquisa
- Biodiesel production from vegetal oil and ethanol via transesterification in supercritical conditions(2023-08-03) SIDI NETO, V.; DERENZO, S.; MARIN, M. P. DE A.; Luis Novazzi; João Guilherme Rocha Poço© 2023, The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química.Biodiesel, which is derived from renewable feedstock, has potential to replace fossil diesel. In this study, biodiesel production was carried out through the transesterification of soybean oil with ethanol (anhydrous and hydrated) under supercritical conditions in a batch reactor, with a temperature range of 280–340 °C and an oil/alcohol molar ratio of 1:40. The effects of both anhydrous and hydrated ethanol on the reaction were evaluated, as well as the direct esterification of oleic acid to produce ethyl ester. A first-order reversible kinetic model was proposed to describe the transesterification process. The results showed a good agreement between experimental data and the model. It was observed that temperature has an important effect on ester yield and hydrated ethanol improved this yield. After 120 min of reaction time at 310 °C with hydrated ethanol, transesterification led to 89.7% of ethyl ester. When compared to anhydrous ethanol, forward rate constants of hydrated ethanol suggested that water may have a catalytic effect on transesterification. Although the transesterification of soybean oil and ethanol under supercritical conditions is nearly irreversible at 280 °C, the reaction is limited by equilibrium at temperatures equal to or higher than 310 °C.
- Direct oxidation of 3-picoline (3-methyl-pyridine) to nicotinic acid with pure HNO3(2023-07-17) GOMES, E. L.; FREITAS, D. A. DE; Rodrigo Condotta; João Guilherme Rocha Poço© 2023, The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química.Nicotinic acid (NA) was synthesized by directly oxidizing 3-methylpyridine (3MP) with nitric acid. The reaction was performed in an instrumented PARR reactor. The effect of temperature (165 to 195 °C) and the molar composition of the initial reactive mixture were studied. Molar conversions of 3-methylpyridine ranged from 36 to 90%, with a yield of NA ranging from 31 to 62%. Better selectivities occur at low-time reactions and low conversion rates. At the same time, the HNO3 excess and temperature considerably affect 3MP conversion rate and NA yield rather than selectivity, especially at 180 °C, whereas an invariable selectivity of 80% was observed.
- Experimental study and correlation of the excess molar volume of binary liquid solutions of (amines + water) at different temperatures and atmospheric pressure(2022-03-05) MUNOZ, P. A. R.; OLIVIERI, G. V.; Ronaldo Santos; Ricardo Torres© 2021, Associação Brasileira de Engenharia Química.Experimental data of density have been measured for binary liquid mixtures containing {amines (n-butylamine, or s-butylamine, or t-butylamine, or diethylamine, or propylamine) + water}, over the entire range of composition at temperatures between 283.15 and 303.15 K, and atmospheric pressure. The density values enabled the determination of the thermal expansion coefficients. The excess molar volume, VmE, was calculated using the experimental data, from which a Redlich–Kister type polynomial was fit, enabling the determination of the partial molar volumes, the excess partial molar volumes, the apparent molar volumes and the excess partial molar volumes at infinite dilution. The VmE values were also used to test the applicability of the Extended Real Associated Solution Model (ERAS Model). The results for the studied systems suggest that structural effects and chemical interactions must predominate over other possible effects. The magnitude of VmE for the studies systems led to the following order: n-butylamine > propylamine > s-butylamine > diethylamine > t-butylamine.
- Effects of rhamnolipid bio-surfactant and sodium dodecylbenzene sulfonate (SDBS) surfactant on enhanced oil recovery from carbonate reservoirs(2022-01-03) IMANIVARNOSFADERANI, M. R.; GOMARI, S. R.; Ronaldo Santos© 2022, Associação Brasileira de Engenharia Química.Bio-surfactant solutions have been point out as a promissory component to replace fossil-derived surfactants to improving the displacement efficiency in enhanced oil recovery (EOR) methods. This study compares the performance of rhamnolipid as a bio-surfactant and sodium dodecylbenzene sulfonate (SDBS) as a synthetic surfactant in EOR from carbonate reservoirs. The effects of their use were evaluated by considering the effect of different levels of salinity and the results of various well-established experimental tests such as of fluid-phase behaviour, wettability alteration, interfacial tension (IFT) reduction, and core flooding. The rhamnolipid bio-surfactant has been recognized as a better surface agent used to change the wettability of calcite to a strong water-wet system in comparison to sodium dodecylbenzene sulfonate. The results confirmed that when the salinity of low-saline brine was increased to 0.6 M, with a concentration of 0.5 wt. % of rhamnolipid, the wettability of the rock surfaces changed to become more water-wet. Also, values of IFT between model oil and low-saline brine were measured as 1.1 ± 0.3 and 2.8 ± 0.4 (mN/m) when using the rhamnolipid and SDBS respectively as modifiers within the aqueous solutions. Finally, the outcomes of core flooding experiments revealed that the rhamnolipid surfactant could minimize flow problems arising from the formation of emulsions, leading to 14.98% higher ultimate oil recovery compared to SDBS.