Navegando por Assunto "Processos de fracionamento"

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Acesso aberto (Open Access)
Estudo comparativo dos processos de separação na obtenção do biodiesel de óleo de palma bruto (Elaeis guineensis, Jacq)
(Universidade Federal do Pará, 2014-05-05) RIBEIRO, Haroldo Jorge da Silva; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
This work investigated the influence of the separation processes on the yield and properties relating to the quality of biodiesel from crude palm oil ( Elaeis guineensis, Jacq ) obtained in laboratory scale , such as decantation , centrifugation , evaporation , washing and dehydration, where the following operating conditions are used : the settling time ( sludge/neutral oil ) - 120 minutes at 50 ° C; settling time used for washing the neutral oil 60, 90 and 120 minutes at 50 °C; H2O percentages used in washing the neutral oil 10%, 20% and 30% ( m./m.); temperatures centrifugation for separating the neutral/oil sludge and washings neutral oil 40, 50 and 60 °C; temperature and pressure range of dehydration of neutral oil and biodiesel and 80 °C from 480,0 to 80,0 mbar respectively; temperature and pressure in the evaporation of excess ethanol 75 °C and 213,3 and 146,6 respectively March; the settling time of biodiesel/glycerol system and washes 60, 90 and 180 minutes at 50 °C; operating temperature used in the centrifuge separation system biodiesel/glycerin 50 °C; H2O percentage of biodiesel used for washing by centrifugation 20% relative to the ester phase. The results found that neutralization in general was satisfactory as generated about 10% of blurs, highlighting the Experiment 1 that generated about 84,6% by weight of neutral oil. Washes in 90 minutes (Exp. 1) and 20% water (exp.2) showed the best performance for the separation by settling, while in the process of centrifugation and washing better separation occurred at 40 and 50 ° C respectively. In relation to the evaporation of ethanol, the best percentage in alcohol was obtained at 80 °C and 1466 mbar. Regarding the separation of phases rich in glycerol esters and the process of centrifugation at 50 °C led to a better quality biodiesel, however, the best yields were observed in the biodiesel from the settling process. The final evaluation of the biodiesel produced in this study was positive, because most of the analyzed parameters is according to the official specifications.
Acesso aberto (Open Access)
Modelagem e simulação de processos de separação a altas pressões: aplicações com Aspen hysys
(Universidade Federal do Pará, 2014) CUNHA, Vânia Maria Borges; MACHADO, Nélio Teixeira de; http://lattes.cnpq.br/5698208558551065; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682
The purpose of this work was to elaborate a database of binary interaction parameters of different mixing rules, for the Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equations of state, using experimental data of binary and multicomponent systems of hydrocarbons, N2, CO2, water, β-carotene, ethanol, acetone and methanol, in order to apply in simulations with the Aspen Hysys fractionation processes, of natural gas into a simplified turbo-expansion process; fractionation of oil, gas and water, in three-phase separator, supercritical CO2 extraction of acetone from an aqueous solution and β-carotene from an aqueous solution in multistage countercurrent column. In general, there were no significant differences, to both equations, in the phase equilibrium prediction of the binary systems studied, between the quadratic and Mathias-Klotz-Prausnitz (MKP) mixing rules with two and three parameters. It is worth mentioning that the MKP mixing rule with 3 binary interaction parameters presented the smallest absolute errors for hydrocarbon binary systems and CO2/hydrocarbons systems. For the settings of hydrocarbons phase equilibrium multicomponent systems data, the SRK equation combined with quadratic mixture rule with 2 binary interaction parameters, was presented the lowest average errors for ternary systems and for system with 5 components in both phases. In the case study of three-phase separator the SRK equation with the mixing rule RK-Aspen was the one that presented the greater separation of the aqueous phase of all simulations (285.68 kg/h) against 256.88 kg/h to the SRK equation, 249.81 kg/h for the PR equation and 152.90 kg/h to PRSV equation, confirming the great influence of the use the binary interaction parameters matrix determined in this work, with emphasis on the parameters that represent the interactions between the hydrocarbons with water. The results of the simulations with the simplified plant turboexpansion are according to the analysis described in the literature showing the following recovery rates of ethane: 84.045% to PRSV, 84.042% for SRK, 84.039% for TST and PR and 83.98% for RK-Aspen. The final product of the simulation published in the literature for the fractionation of an aqueous solution of acetone by using supercritical CO2 extraction process consisted in the output current from the bottom of the distillation column at 65 atm (6586 kPa), with a composition of 67.67% CO2 (74.3 kg/h), 31.11% of acetone (34.15 kg/h) and 1.21% (1.33 kg/h) of water in mass base. In the simulation with Aspen Hysys the output current of the distillation column was subjected to a set of flash separators for separation of CO2 reaching the recovery of 27 kg/h of acetone in three currents (11.14 and 15) with less than 5 kg/h CO2 waste and 0.8 kg/h of water. The fractionation of aqueous solution of β- carotene was simulated with the Aspen Hysys, with a multistage countercurrent column and a vertical flash separator for separation of CO2. The simulations have converged with a minimum of five stages. It was retrieved from an underflow (product) flash separator with 97.83% of β-carotene against 89.95% by mass for the simulation of an extractor of a single stage published in the literature.
Acesso aberto (Open Access)
Simulação do fracionamento em coluna em contracorrente de óleo de peixe e de solução aquosa com dióxido de carbono supercrítico
(Universidade Federal do Pará, 2015-08-11) SILVA, Marcilene Paiva da; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682
This work had as its general objective the simulation with Aspen Hysys fractionation process using supercritical carbon dioxide in countercurrent multistage columns of an aqueous solution of ethanol and fish oil, employing cubic equations of state with binary interaction parameters extracted from a database previously prepared with different mixing rules for the equations of state of Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), their respective modified and Redlich-Kwong Aspen (RK-Aspen), from experimental data of binary systems of methyl and ethyl esters, esters of fatty acids from fish oil, biocompounds, aqueous systems and minority components of vegetable oils. Overall, no significant differences in the prediction of phase balance for all equations of state used with the mixing rules of Quadratic, Mathias-Klotz-Prausnitz (MKP) with 2 and 3 parameters, KM1 with 3 parameters and RKAspen with 2 and 4 parameters. It is worth mentioning that the mixing rule RK-Aspen with 4 binary interaction parameters, presented the smallest absolute errors for most systems. The simulator used the equation of state of Soave-Redlich-Kwong as a thermodynamic package with the mixing rules of RK-Aspen. The simulations to 140 and 145 bar pressure and 60° C for the P1 and P8 showed that increased concentration (eC20:53) and ( eC22:63) occurred at the expense of the solvent consumption (carbon dioxide), i.e. with the increase of the ratio S/F, reaching 85.67% for S/F = 200 for P1 and 70.61% for S/F = 150 to the composition P8. The simulation results of this study at 145 bar and 60° C, with relations S/F of 70, 90, 110 and 130, using different fish oil compositions, exhibited higher yield of raffinate stream compared to simulated column literature, in the Aspen Plus using Peng-Robinson equation for all the relations S / F. As the quality of recovery of the compounds of interest (eC20:53 e eC22:63), both simulations showed similar performance. For the fractionation process of aqueous solutions were performed at 101 bar pressure and temperature of 333 K. The results showed that the simulations reproduced the experiments on most operating conditions in laboratory scale, pilot and industrial published in the literature.