Phase equilibrium measurements and thermodynamic modelling for the system (CO2+ethyl palmitate+ethanol) at high pressures (original) (raw)
Related papers
2012
This work reports phase equilibrium data at high pressures for the binary and ternary systems formed by propane + n-methyl-2-pyrrolidone (NMP) + methanol. Phase equilibrium measurements were performed in a high-pressure variable-volume view cell, following the static synthetic method for obtaining the experimental bubble and dew points transition data in the temperature range of 363-393 K, pressures up to 16 MPa and overall molar fraction of the lighter component varying from 0.1 to 0.998. For the systems investigated, vapor-liquid (VLE), liquid-liquid (LLE) and vapor-liquid-liquid (VLLE) phase transitions were visually recorded. Results show that the systems investigated present UCST (upper critical solution temperature) phase transition curves with an UCEP (upper critical end point) at a temperature higher than the propane critical temperature. The experimental data were modeled using the Peng-Robinson equation of state with the Wong-Sandler and the classical quadratic mixing rules, affording a satisfactory representation of the experimental data.
In this work, experimental vapor–liquid equilibrium (T, p, x i , y i) data for the ternary carbon dioxide–ethanol–nonane and carbon dioxide–ethanol–decane systems are reported in the temperature range of 313–373 K from low pressures to the nearest of the corresponding critical pressure. Measurements were performed in an apparatus based on the static-analytic method with an on-line ROLSI sampler-injector device. Vapor–liquid equilibrium (VLE) data for both ternary systems are predicted using the Peng–Robinson equation of state coupled to the Wong–Sandler, one parameter van der Waals and two parameters van der Waals mixing rules. Binary interaction parameters are obtained from the VLE data of binary mixtures reported in the literature.
The Journal of Supercritical Fluids, 2008
Vapor-liquid equilibria (VLE) data for the carbon dioxide + ethanol system at 293.15, 303.15, 313.15, 333.15, and 353.15 K up to 11.08 MPa are reported. The experimental method used in this work was a staticanalytical method with liquid and vapor phase sampling. The new experimental results are discussed and compared with available literature data. Measured VLE data and literature data for carbon dioxide + ethanol system were modeled with a general cubic equation of state (GEOS) using classical van der Waals (two parameters conventional mixing rule-2PCMR) mixing rules. A single set of interaction parameters was used to calculate the global phase behavior in the binary mixture carbon dioxide + ethanol in a wide range of temperatures (283.3-453.15 K).
Journal of Chemical & Engineering Data, 2006
This work reports experimental phase equilibrium data of binary and ternary systems involving carbon dioxide, propane, and glycidyl methacrylate (GMA). Phase equilibrium experimental data were obtained according to the static synthetic method using a variable volume view cell. The experiments covered the temperature range of (303 to 343) K, pressures up to 13 MPa, at several overall compositions. The experimental data were modeled with the Peng-Robinson equation of state (PR-EoS) with the conventional quadratic mixing rules. The EoS interaction parameters were fitted from binary systems and then used to predict the phase behavior of the ternary system. The results showed that, in the experimental range investigated, only vapor-liquid transitions were found and that the PR-EoS was capable of satisfactorily representing the experimental data.
The Journal of Supercritical Fluids, 2014
High pressure vapor-liquid equilibrium (VLE) of CO 2-expanded organic solvents was investigated using Peng-Robinson-LCVM-UNIFAC equation of state. Bubble pressure of several ternary mixtures was predicted using this model and correlations were developed based only on binary experimental data. A sensitivity study of the LCVM parameter numerical value was done by considering the coherence between the mathematical features of the mixing rule and the quality of the simulation. The results provided by PR-LCVM-UNIFAC were compared with those ones given by Peng-Robinson equation of state using the classical quadratic mixing rules (PR-CMR). Despite the use of two adjustable parameters for each binary system, PR-CMR is not able to provide good results when applied to ternary systems. The capability of PR-LCVM-UNIFAC model to predict liquid mixture density for ternary systems using parameters regressed only from bubble pressure experimental data was also investigated. Due to the lack of liquid density experimental data, it was possible to perform only a qualitative assessment of the density curves calculated by this equation of state.
Journal of Chemical Thermodynamics, 2010
This work reports phase equilibrium measurements for the ternary system (palmitic acid + ethanol + CO2). The motivation of this research relies on the fact that palmitic acid is the major compound of several vegetable oils. Besides, equilibrium data for palmitic acid in carbon dioxide using ethanol as co-solvent are scarce in the literature. Phase equilibrium experiments were performed using a high-pressure variable-volume view cell over the temperature range of (303 to 343) K and pressures up to 20 MPa and mole fraction of palmitic acid from 0.0199 to 0.2930. Vapour–liquid and solid–fluid transitions were visually observed for the system studied. The Peng–Robinson equation of state, with the classical van der Waals quadratic mixing rule was employed for thermodynamic modelling of the system investigated with a satisfactory agreement between experimental and calculated values.
Phase behavior measurement for the system CO2+glycerol+ethanol at high pressures
The Journal of Supercritical Fluids, 2012
This work reports phase equilibrium measurements for the ternary system CO 2 + glycerol + ethanol. Experiments were performed in a high pressure variable-volume view cell at temperatures ranging from 303.15 K to 343.15 K and pressures up to 26 MPa. The CO 2 molar fraction varied from 0.1308 to 0.9871, and glycerol to ethanol molar ratios studied were 1:12, 1:20, and 1:30. For the systems investigated, vapor-liquid (VL), liquid-liquid (LL), and vapor-liquid-liquid (VLL) phase transitions were observed. Phase equilibrium data measured for the ternary system aim the better understanding of the phase behavior knowledge of the glycerol in the ethanol + CO 2 mixture at high pressure system.
High pressure vapor–liquid equilibrium for the ternary system ethanol/(±)-menthol/carbon dioxide
Journal of Supercritical Fluids, 2014
In this work the phase behavior of the ternary system ethanol/(±)-menthol /CO 2 was studied at the temperatures of 313 and 323 K, in the pressure range 8-10 MPa. Experiments were performed using a high pressure phase equilibrium apparatus with a visual cell. CO 2 is more selective towards ethanol, separation factors ranging from 1.6 to 7.6 at the conditions tested. The pTxy data obtained were correlated with the Peng-Robinson equation of state combined with the Mathias-Klotz-Prausnitz mixing rule. The model gave a good fitting to the data, with a total average absolute deviation of 3.7%, and was able to predict the occurrence of a threephase region observed experimentally at 313 K and 9 MPa.
Phase equilibrium data of the system CO2+glycerol+methanol at high pressures
The Journal of Supercritical Fluids, 2011
In this work, phase equilibrium data of the ternary system CO 2 (1) + glycerol(2) + methanol(3) at high pressures are presented. The static synthetic method using a variable-volume view cell was employed to obtain the phase envelope in the temperature range of 303.15-343.15 K and at pressures up to 22 MPa. For the pressure transition measurements a given amount of carbon dioxide was injected into a methanol:glycerol mixture with a known molar ratio. Three different methanol to glycerol molar ratios were investigated (1:30, 1:20 and 1:12). The mole fraction of carbon dioxide was varied according to the system as follows: 0.3373-0.9741 for the glycerol to methanol molar ratio of 1:30, 0.2524-0.9949 for the molar ratio of 1:20, 0.2625-0.9940 for the molar ratio of 1:12. A complex phase behavior including vapor-liquid (VL), liquid-liquid (LL) and vapor-liquid-liquid (VLL) transitions were observed for these systems.
Chemical Engineering Transactions, 2017
In this work, binary and ternary systems composed by hydrocarbons and CO2 in liquid-vapor equilibrium conditions (LV) were thermodynamically modeled using Peng-Robinson (PR) and Patel-Teja (PT) equations of state (EoS) in combination with van der Waals mixing rule with two adjustable parameters (vdW -2, kij and lij). The model was formulated as a minimization of the Mean Absolute Deviation (%AAD) between the predicted and experimental values for liquid and vapor phases using the simplex algorithm, through the software Phase- Equilibrium 2000 (PE-2000). Low deviations, %AAD = 2.33% for PR EoS and %AAD = 3.06% for PT EoS were observed for binary systems in the evaluation of 160 experimental points (EP). Ternary systems were modeled with low deviations too, %AAD = 1.12% for EoS PR and %AAD = 1.18% for EoS PT were observed in the evaluation of 69 EP. Both tested EoS proved to be useful to represent LV equilibrium in this kind of system.