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Navegando IQ - Artigos publicados em periódicos por Autor "Alcantara, Murilo Leite"
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Item Amine/carboxylic acid ionic liquid composite membranes for CO2 separation(2021) Alcantara, Murilo Leite; Oliveira, Gerlon de Almeida Ribeiro; Liao, Luciano Morais; Borges, Cristiano Piacsek; Silva, Silvana Mattedi eAlkanolamine + carboxylic acid-based ionic liquids have shown promising high CO2 selectivities. Their addition to cellulose acetate (CA) and polyvinyl alcohol (PVA) was investigated in the present study. The N-methyl-2-hydroxyethylammonium propionate IL [m-2HEA][Pr] significantly enhances the CO2 separation performance of PVA. Scanning electron microscopy, Fourier transform infrared spectroscopy, and nuclear magnetic resonance analyses indicate that the IL–PVA combination produced IL composite membranes with interactions being predominantly physical. Furthermore, the IL addition to CA produced porous membranes with apparent low CO2 separation efficiency. Pure gas permeation experiments indicate that increasing IL concentration of PVA-based membranes promotes higher gas permeabilities. The membranes were prepared containing up to 60.3 wt % of [m-2HEA][Pr], which resisted pressure differentials up to 6 barg. PVA containing 45.5 wt % of IL produced the most promising results, achieving 26 barrer of CO2 permeability and permselectivities of 122 and 213 for CO2/CH4 and CO2/N2, respectively. This result was compared to promising materials from the literature and indicated the overall high CO2/CH4 and CO2/N2 selectivities of PVA/[m-2HEA][Pr] membranes, which overcome even the 2008 Robeson’s upper boundary.Item High pressure vapor-liquid equilibria for binary carbon dioxide and protic ionic liquid based on ethanolamines + butanoic acid(2018) Alcantara, Murilo Leite; Carvalho, Marlon Loreno de; Álvarez, Víctor Hugo; Ferreira, Pedro Ícaro dos Santos; Paredes, Márcio Luis Lyra; Cardozo Filho, Lúcio; Silva, Andressa Kuhnen; Liao, Luciano Morais; Pires, Carlos Augusto de Moraes; Silva, Silvana Mattedi eHigh pressure phase equilibria data were measured for 3 protic ionic liquids and CO2. The studied ILs were based on ethanolamine cations and butanoate anions: 2-hydroxyethylammonium butanoate [2HEA][Bu]; N-methyl-2-hydroxyethylammonium butanoate [m-2HEA][Bu] and N-ethyl-2-hydroxyethylammonium butanoate [e−2HEA][Bu]. This ILs were chosen in order to study the effect of the alkyl growth, from central amine, on CO2 solubility. Water content, FT-IR, 1H and 13C NMR analysis were performed on samples. Charge profiles were also estimated by the geometrical and energetic optimization of ILs structures. The data were correlated with three models: Carvalho and Coutinho predictive empirical correlation; Peng-Robinson EoS; Peng-Robinson EoS coupled with Wong-Sandler/NRTL or two parameters mixing rules; Predictive ternary PC-SAFT model. The results showed that the increase of the carbon chain length, bonded to the amine group, promotes higher CO2 solubility at medium-high pressures but lower CO2 solubility at low pressures. Henry's law constants were also compared to other ILs ones.Item High pressure vapor-liquid equilibria for binary protic ionic liquids + methane or carbon dioxide(2018) Alcantara, Murilo Leite; Ferreira, Pedro Ícaro dos Santos; Pisoni, Gerardo Oscar; Silva, Andressa Kuhnen; Cardozo Filho, Lúcio; Liao, Luciano Morais; Silva, Silvana Mattedi eThis study reports the high pressure phase transition data for both methane and carbon dioxide and two large protic ionic liquids: N-methyl-2-hydroxyethylammonium propanoate [m-2HEA][Pr] and bis(2-hydroxyethyl)ammonium butanoate [BHEA][Bu]. The experimental data were obtained using the static-synthetic visual method by a variable-volume cell unit. The apparatus and experimental methodology were validated by methane + N-methyl-2-hydroxyethylammonium propanoate equilibrium data. The low deviation between the data indicates the experimental data is consistent with previous literature. Structure and purity of ILs were confirmed by FT-IR spectroscopy, 1H and 13C NMR studies. Water contents were measured by Karl Fischer volumetric measurements. NMRs and water contents analyses were performed on samples collected before and after the experiments. The phase transitions were classified as bubble points and studied at five temperatures from 313.1 to 353.1 K and pressures up to 20 MPa. Experimental data were correlated using the three-parametric Redlich Kwong – Peng Robinson equation of state (RKPR-EoS) coupled to mixing rules van der Waals type, cubic regarding the composition, and temperature dependence for the interaction energy parameter (CMR-T). Henry’s law constants and ideal CO2/CH4 selectivities were calculated from this model and compared to other ILs ones.Item Low viscosity protic ionic liquid for CO2/CH4 separation: thermophysical and high-pressure phase equilibria for diethylammonium butanoate(2018) Alcantara, Murilo Leite; Santos, Joao Paulo Silva; Carvalho, Marlon Loreno de; Ferreira, Pedro Ícaro dos Santos; Paredes, Márcio Luis Lyra; Cardozo Filho, Lúcio; Silva, Andressa Kuhnen; Liao, Luciano Morais; Pires, Carlos Augusto de Moraes; Silva, Silvana Mattedi eThis is a study of a potential low viscous protic IL to be used in CO2 capture processes. High-pressure phase equilibria data were measured for diethylammonium butanoate [DEA][Bu] + CO2, CH4 or N2 from 303 to 333 K and up to 20 MPa. The experimental data of density, viscosity and sound speed were measured from mixtures of [DEA][Bu] + water with different water amounts and at several temperatures. This protic ionic liquid was characterized by water content, FT-IR, 1H and 13C NMR, which were used to determine the IL molecular structure and estimate its purity, before and after phase equilibria experiments. A comparison among 38 ionic liquids indicates that [DEA][Bu] has a significantly low viscosity. Phase equilibria data were adjusted by Peng-Robinson and sPC-SAFT EoSs with high accuracy, mainly for CO2 data. sPC-SAFT also well fitted the density and sound speed of pure [DEA][Bu] (dev. < 0.2%). [DEA][Bu] Henry's law constants and ideal CO2/CH4 selectivity values were compared with those of other ILs at different temperatures, molecular weights and pressures. The comparisons indicate that [DEA][Bu] presents moderate to low CO2 solubilities and CO2/CH4 selectivities but a low pressure sensibility. Thus, at high pressures, this PIL would present higher selectivities than most ILs studied.