Eva Rodil | University of Santiago de Compostela (original) (raw)
Papers by Eva Rodil
Ionic Surfactants and Aqueous Solutions
Fluid Phase Equilibria, 2022
Orange processing generates a high amount of waste rich in natural compounds that can be used to ... more Orange processing generates a high amount of waste rich in natural compounds that can be used to obtain added-value products or as raw material in biorefineries. Limonene (terpene) and linalool (oxygenated terpene) stand out among those bioproducts due to their organoleptic, antioxidant and preservative properties. They are widely used in the food, cosmetic and chemical industries, but their use as Generally Recognized As Safe solvents is also gaining interest. In this work, the separation of the mixture limonene and linalool is proposed by extractive distillation with the ionic liquid 1-butyl-3methylimidazolium acetate. To that aim, isobaric vapor-liquid equilibrium at 5 kPa was determined for the binary and ternary systems involved, and the data were successfully correlated with the NRTL and UNIQUAC models. The process was simulated, and the recovery of the ionic liquid was tested with a flash unit at very low pressure (0.1 kPa), or a stripping column (5 stages, 101.32 kPa) with air at the maximum operating temperature and a gas-liquid separator (101.32 kPa, 298.15 K). In the second case, an extractive column with an entrainer flow rate of 100 kg/h, number of stages N=20, and reflux ratio R=0.5 allows the separation of practically pure limonene and linalool.
Fluid Phase Equilibria, 2018
Potassium tartrate solubility in water was measured and the aqueous biphasic system formed by thi... more Potassium tartrate solubility in water was measured and the aqueous biphasic system formed by this organic salt and PEG (1500 or 600) were characterized experimentally at 278.15, 293.15 and 308.15 K by measuring the composition of the equilibrium phases. The experimental binodal curves and the tie-lines were correlated using Merchuk and Guan equations. As expected for polymer-salt Aqueous Two-Phase Systems, the heterogeneous region increases with temperature and polymer molecular weight. Their effect on the phase behavior are discussed and related to the models' parameters.
![Research paper thumbnail of Photocatalytic degradation of methyl orange, methylene blue and rhodamine B with AgCl nanocatalyst synthesised from its bulk material in the ionic liquid [P6 6 6 14]Cl](https://attachments.academia-assets.com/95153275/thumbnails/1.jpg)
](Water Science and Technology, 2016
The photocatalytic degradation of wastewater containing three industrial dyes belonging to differ... more The photocatalytic degradation of wastewater containing three industrial dyes belonging to different families, methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB), was studied under UV-Vis irradiation using synthesised silver chloride nanoparticles. The nanocatalyst was prepared by a dissolution/reprecipitation method starting from the bulk powder and the ionic liquid trihexyl(tetradecyl)phosphonium chloride, [P6 6 6 14]Cl, without addition of other solvents. The obtained catalyst was characterised by UV-Vis absorbance, X-ray powder diffraction, transmission electron microscopy and scanning electron microscopy. The decolourisation of the samples was studied by UV-Vis absorbance at the corresponding wavelength. Starting from 10 ppm dye solutions and 1 g L−1 of the synthesised AgCl nanoparticles, degradation efficiencies of 98.4% for MO, 98.6% for MB and 99.9% for RhB, were achieved in 1 h. The degradation mechanisms for the different dyes were studied. Comparison with other...
Nanotechnology, 2008
Nanoparticles of silver halides have been prepared by mixing silver halide powder with a single l... more Nanoparticles of silver halides have been prepared by mixing silver halide powder with a single liquid phase consisting of an ionic liquid, isooctane, n-decanol and water. Much higher nanoparticle concentrations may be formed with ionic liquids using this new simple method than are found with conventionally applied surfactants. This method also emphasizes the applicability of ionic liquids as versatile components in microemulsions and as solvents for the synthesis of nanomaterials. The effect on the nanoparticles of changing the composition of the liquid mixtures and the nature of the ionic liquid is analysed. High nanoparticle concentrations were only found with chloride based ionic liquids, indicating the importance of the ionic liquid anion in the mechanism of the reaction.
Bulletin of the Chemical Society of Japan, 1974
Journal of Molecular Liquids
Ionic Surfactants and Aqueous Solutions, 2018
Journal of Molecular Liquids, 2021
Separation and Purification Technology, 2020
Abstract The ionic liquids 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) and 1-ethyl-3-meth... more Abstract The ionic liquids 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) and 1-ethyl-3-methylimidazolium thiocyanate ([C2mim][SCN]) have been proposed to improve many processes from the point of view of efficiency and/or sustainability. In a number of those proposals, mixtures of these ionic liquids with alcohols are generated. On the assumption of easy separation of the volatile alcohol and the totally non-volatile ionic liquid by distillation, little attention has been paid to the recovery of the ionic liquid to date. However, this is a critical step to transform a process tested at laboratory level into an industrial reality. To analyse the viability of using distillation to recover the above mentioned ionic liquids from their mixtures with methanol or ethanol, in this work the isobaric vapour-liquid equilibria of the corresponding binary systems at pressures of 101.32, 50, and 25 kPa were determined. Several physical and derived properties were also determined for the studied systems at 298.15 K and atmospheric pressure. The simulation of a flash unit, using the correlation of the experimental data with the NRTL model, was carried out with Aspen Plus at different temperatures and pressures. High ionic liquid purities were obtained in the case of the systems comprising [C2mim][SCN], which could be satisfactorily recovered at moderate vacuum. However, in the case of systems involving [C2mim][OAc], the recovery was limited by the relatively low degradation temperature of this ionic liquid.
Separation and Purification Technology, 2020
Abstract Deterpenation of an essential oil improves its stability and quality, thus increasing it... more Abstract Deterpenation of an essential oil improves its stability and quality, thus increasing its market value. In this work, different unit operations to carry out the deterpenation of citrus essential oil were evaluated by simulation. The selected processes were: liquid-liquid extraction using the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) as solvent, vacuum distillation, and extractive distillation using [C2mim][OAc] as entrainer. A pressure of 5 kPa was selected for distillation processes in order to maintain the organoleptic properties of the essential oil. To that aim, isobaric vapor-liquid equilibria were determined at that pressure for limonene + linalool and linalool + [C2mim][OAc] binary, and limonene + linalool + [C2mim][OAc] ternary, systems. NRTL adequately correlated experimental data and the obtained parameters were used for simulations. Liquid-liquid extraction was shown to be unsuccessful in providing a significant deterpenation. Distillation allowed the recovery of all the fed linalool (100 kg/h) almost pure, but very demanding conditions were required: a reflux ratio and number of plates of 3 and 45, respectively. The use of [C2mim][OAc] as entrainer increases the relative volatility of limonene and linalool, and greatly facilitates their separation by reducing the reflux ratio and number of plates required to 1 and 20 respectively, and also diminishes the energy requirements. The vacuum level of the flash unit used to recover the entrainer drastically affects the essential oil production rate.
Biochemical Engineering Journal, 2018
Biotechnology progress, 2018
Fluid Phase Equilibria, 2016
Abstract PEG (4000 or 8000)-(Ammonium or Sodium) Sulfate Aqueous Two-Phase Systems were character... more Abstract PEG (4000 or 8000)-(Ammonium or Sodium) Sulfate Aqueous Two-Phase Systems were characterized at 278.15, 293.15 and 308.15 K. Two physical properties (density and refractive index) were used to obtain the compositions of the ends of the tie-lines. The binodal curve was constructed from these end points. A comparison with some available data at close temperatures allowed for assessing different experimental techniques. Data correlation for the experimental binodal curves and tie-lines was carried out using Merchuk and Guan’s equations. The effect of temperature, polymer molecular weight and nature of the cation of the salt on the phase diagram were assessed using these models. It has been found that the heterogeneous region increases with temperature, polymer molecular weight, or the hydration shell (salting-out) of the cations. PEG 8000 and sodium sulfate formed the largest heterogeneous region, thus needing the smallest amount of phase-forming components for phase splitting.
The Journal of Chemical Thermodynamics, 1998
(Vapour+liquid) equilibrium data for (ethanol+methanol+2-methoxy-2-methylbutane) were measured an... more (Vapour+liquid) equilibrium data for (ethanol+methanol+2-methoxy-2-methylbutane) were measured and compared with predictions from group-contribution methods. The experimental data were determined in a still that recycled both liquid and vapour phases, and their thermodynamic consistency was demonstrated using Wisniak's L-W test, and Wisniak and Tamir's modification of the McDermott–Ellis test. The data were correlated using the Wilson, NRTL, and UNIQUAC equations in
The densities, refractive indexes, and sound velocities for mixtures of ethanol + methanol + dibu... more The densities, refractive indexes, and sound velocities for mixtures of ethanol + methanol + dibutyl ether at 25°C and atmospheric pressure, were determined and used to calculate molar volumes, molar refractions, and isentropic compressibilities. The excess molar volumes and the deviations of molar refractions and isentropic compressibilities from mole fraction and volume fraction averages, respectively, of these properties of the pure components were satisfactorily correlated with the composition data by means of the Redlich-Kister polynomial.
Langmuir, 2003
Nanoparticles of silver chloride were prepared by direct precipitation of silver ions with the su... more Nanoparticles of silver chloride were prepared by direct precipitation of silver ions with the surfactant counterion in the water pools of microemulsions formed by dioctyldimethylammonium chloride in an organic n-decanol/isooctane phase. This work represents a new concept to form ...
Journal of Materials Science, 2015
Silver chloride nanoparticles have been successfully prepared by an easy and quick method using s... more Silver chloride nanoparticles have been successfully prepared by an easy and quick method using solely the corresponding powder material and an ionic liquid. No other precursors or volatile solvents are needed, in contrast to other synthesis methods less environmentally friendly. The obtained nanoparticles were characterised by X-ray powder diffraction, UV-vis spectroscopy, transmission electron microscopy and scanning electron microscopy. The photocatalytic activity of the nanoparticles was tested for the degradation of industrial dyes under UV radiation. Orange II was chosen as a model dye to perform the experiments. The effect of dye concentration, catalyst loading and solution pH on this activity was studied. It was found that, in optimal conditions, a total degradation of the dye can be reached in only 30 min. The kinetic of the photodegradation followed a first-order reaction model, being proposed a possible photocatalytic reaction mechanism. The recyclability of the nanomaterial as catalyst was positively tested.
Ionic Surfactants and Aqueous Solutions
Fluid Phase Equilibria, 2022
Orange processing generates a high amount of waste rich in natural compounds that can be used to ... more Orange processing generates a high amount of waste rich in natural compounds that can be used to obtain added-value products or as raw material in biorefineries. Limonene (terpene) and linalool (oxygenated terpene) stand out among those bioproducts due to their organoleptic, antioxidant and preservative properties. They are widely used in the food, cosmetic and chemical industries, but their use as Generally Recognized As Safe solvents is also gaining interest. In this work, the separation of the mixture limonene and linalool is proposed by extractive distillation with the ionic liquid 1-butyl-3methylimidazolium acetate. To that aim, isobaric vapor-liquid equilibrium at 5 kPa was determined for the binary and ternary systems involved, and the data were successfully correlated with the NRTL and UNIQUAC models. The process was simulated, and the recovery of the ionic liquid was tested with a flash unit at very low pressure (0.1 kPa), or a stripping column (5 stages, 101.32 kPa) with air at the maximum operating temperature and a gas-liquid separator (101.32 kPa, 298.15 K). In the second case, an extractive column with an entrainer flow rate of 100 kg/h, number of stages N=20, and reflux ratio R=0.5 allows the separation of practically pure limonene and linalool.
Fluid Phase Equilibria, 2018
Potassium tartrate solubility in water was measured and the aqueous biphasic system formed by thi... more Potassium tartrate solubility in water was measured and the aqueous biphasic system formed by this organic salt and PEG (1500 or 600) were characterized experimentally at 278.15, 293.15 and 308.15 K by measuring the composition of the equilibrium phases. The experimental binodal curves and the tie-lines were correlated using Merchuk and Guan equations. As expected for polymer-salt Aqueous Two-Phase Systems, the heterogeneous region increases with temperature and polymer molecular weight. Their effect on the phase behavior are discussed and related to the models' parameters.
Water Science and Technology, 2016
The photocatalytic degradation of wastewater containing three industrial dyes belonging to differ... more The photocatalytic degradation of wastewater containing three industrial dyes belonging to different families, methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB), was studied under UV-Vis irradiation using synthesised silver chloride nanoparticles. The nanocatalyst was prepared by a dissolution/reprecipitation method starting from the bulk powder and the ionic liquid trihexyl(tetradecyl)phosphonium chloride, [P6 6 6 14]Cl, without addition of other solvents. The obtained catalyst was characterised by UV-Vis absorbance, X-ray powder diffraction, transmission electron microscopy and scanning electron microscopy. The decolourisation of the samples was studied by UV-Vis absorbance at the corresponding wavelength. Starting from 10 ppm dye solutions and 1 g L−1 of the synthesised AgCl nanoparticles, degradation efficiencies of 98.4% for MO, 98.6% for MB and 99.9% for RhB, were achieved in 1 h. The degradation mechanisms for the different dyes were studied. Comparison with other...
Nanotechnology, 2008
Nanoparticles of silver halides have been prepared by mixing silver halide powder with a single l... more Nanoparticles of silver halides have been prepared by mixing silver halide powder with a single liquid phase consisting of an ionic liquid, isooctane, n-decanol and water. Much higher nanoparticle concentrations may be formed with ionic liquids using this new simple method than are found with conventionally applied surfactants. This method also emphasizes the applicability of ionic liquids as versatile components in microemulsions and as solvents for the synthesis of nanomaterials. The effect on the nanoparticles of changing the composition of the liquid mixtures and the nature of the ionic liquid is analysed. High nanoparticle concentrations were only found with chloride based ionic liquids, indicating the importance of the ionic liquid anion in the mechanism of the reaction.
Bulletin of the Chemical Society of Japan, 1974
Journal of Molecular Liquids
Ionic Surfactants and Aqueous Solutions, 2018
Journal of Molecular Liquids, 2021
Separation and Purification Technology, 2020
Abstract The ionic liquids 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) and 1-ethyl-3-meth... more Abstract The ionic liquids 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) and 1-ethyl-3-methylimidazolium thiocyanate ([C2mim][SCN]) have been proposed to improve many processes from the point of view of efficiency and/or sustainability. In a number of those proposals, mixtures of these ionic liquids with alcohols are generated. On the assumption of easy separation of the volatile alcohol and the totally non-volatile ionic liquid by distillation, little attention has been paid to the recovery of the ionic liquid to date. However, this is a critical step to transform a process tested at laboratory level into an industrial reality. To analyse the viability of using distillation to recover the above mentioned ionic liquids from their mixtures with methanol or ethanol, in this work the isobaric vapour-liquid equilibria of the corresponding binary systems at pressures of 101.32, 50, and 25 kPa were determined. Several physical and derived properties were also determined for the studied systems at 298.15 K and atmospheric pressure. The simulation of a flash unit, using the correlation of the experimental data with the NRTL model, was carried out with Aspen Plus at different temperatures and pressures. High ionic liquid purities were obtained in the case of the systems comprising [C2mim][SCN], which could be satisfactorily recovered at moderate vacuum. However, in the case of systems involving [C2mim][OAc], the recovery was limited by the relatively low degradation temperature of this ionic liquid.
Separation and Purification Technology, 2020
Abstract Deterpenation of an essential oil improves its stability and quality, thus increasing it... more Abstract Deterpenation of an essential oil improves its stability and quality, thus increasing its market value. In this work, different unit operations to carry out the deterpenation of citrus essential oil were evaluated by simulation. The selected processes were: liquid-liquid extraction using the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) as solvent, vacuum distillation, and extractive distillation using [C2mim][OAc] as entrainer. A pressure of 5 kPa was selected for distillation processes in order to maintain the organoleptic properties of the essential oil. To that aim, isobaric vapor-liquid equilibria were determined at that pressure for limonene + linalool and linalool + [C2mim][OAc] binary, and limonene + linalool + [C2mim][OAc] ternary, systems. NRTL adequately correlated experimental data and the obtained parameters were used for simulations. Liquid-liquid extraction was shown to be unsuccessful in providing a significant deterpenation. Distillation allowed the recovery of all the fed linalool (100 kg/h) almost pure, but very demanding conditions were required: a reflux ratio and number of plates of 3 and 45, respectively. The use of [C2mim][OAc] as entrainer increases the relative volatility of limonene and linalool, and greatly facilitates their separation by reducing the reflux ratio and number of plates required to 1 and 20 respectively, and also diminishes the energy requirements. The vacuum level of the flash unit used to recover the entrainer drastically affects the essential oil production rate.
Biochemical Engineering Journal, 2018
Biotechnology progress, 2018
Fluid Phase Equilibria, 2016
Abstract PEG (4000 or 8000)-(Ammonium or Sodium) Sulfate Aqueous Two-Phase Systems were character... more Abstract PEG (4000 or 8000)-(Ammonium or Sodium) Sulfate Aqueous Two-Phase Systems were characterized at 278.15, 293.15 and 308.15 K. Two physical properties (density and refractive index) were used to obtain the compositions of the ends of the tie-lines. The binodal curve was constructed from these end points. A comparison with some available data at close temperatures allowed for assessing different experimental techniques. Data correlation for the experimental binodal curves and tie-lines was carried out using Merchuk and Guan’s equations. The effect of temperature, polymer molecular weight and nature of the cation of the salt on the phase diagram were assessed using these models. It has been found that the heterogeneous region increases with temperature, polymer molecular weight, or the hydration shell (salting-out) of the cations. PEG 8000 and sodium sulfate formed the largest heterogeneous region, thus needing the smallest amount of phase-forming components for phase splitting.
The Journal of Chemical Thermodynamics, 1998
(Vapour+liquid) equilibrium data for (ethanol+methanol+2-methoxy-2-methylbutane) were measured an... more (Vapour+liquid) equilibrium data for (ethanol+methanol+2-methoxy-2-methylbutane) were measured and compared with predictions from group-contribution methods. The experimental data were determined in a still that recycled both liquid and vapour phases, and their thermodynamic consistency was demonstrated using Wisniak's L-W test, and Wisniak and Tamir's modification of the McDermott–Ellis test. The data were correlated using the Wilson, NRTL, and UNIQUAC equations in
The densities, refractive indexes, and sound velocities for mixtures of ethanol + methanol + dibu... more The densities, refractive indexes, and sound velocities for mixtures of ethanol + methanol + dibutyl ether at 25°C and atmospheric pressure, were determined and used to calculate molar volumes, molar refractions, and isentropic compressibilities. The excess molar volumes and the deviations of molar refractions and isentropic compressibilities from mole fraction and volume fraction averages, respectively, of these properties of the pure components were satisfactorily correlated with the composition data by means of the Redlich-Kister polynomial.
Langmuir, 2003
Nanoparticles of silver chloride were prepared by direct precipitation of silver ions with the su... more Nanoparticles of silver chloride were prepared by direct precipitation of silver ions with the surfactant counterion in the water pools of microemulsions formed by dioctyldimethylammonium chloride in an organic n-decanol/isooctane phase. This work represents a new concept to form ...
Journal of Materials Science, 2015
Silver chloride nanoparticles have been successfully prepared by an easy and quick method using s... more Silver chloride nanoparticles have been successfully prepared by an easy and quick method using solely the corresponding powder material and an ionic liquid. No other precursors or volatile solvents are needed, in contrast to other synthesis methods less environmentally friendly. The obtained nanoparticles were characterised by X-ray powder diffraction, UV-vis spectroscopy, transmission electron microscopy and scanning electron microscopy. The photocatalytic activity of the nanoparticles was tested for the degradation of industrial dyes under UV radiation. Orange II was chosen as a model dye to perform the experiments. The effect of dye concentration, catalyst loading and solution pH on this activity was studied. It was found that, in optimal conditions, a total degradation of the dye can be reached in only 30 min. The kinetic of the photodegradation followed a first-order reaction model, being proposed a possible photocatalytic reaction mechanism. The recyclability of the nanomaterial as catalyst was positively tested.