High pressure vapor–liquid equilibrium for the ternary system ethanol/(±)-menthol/carbon dioxide (original) (raw)
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The Journal of Chemical Thermodynamics, 2013
This work reports phase equilibrium measurements for the binary {CO 2 (1) + ethyl palmitate(2)} and ternary {CO 2 (1) + ethyl palmitate(2) + ethanol(3)} systems at high pressures. There is currently great interest in biodiesel production processes involving supercritical and/or pressurized solvents, such as non-catalytic supercritical biodiesel production and enzyme-catalysed biodiesel production. Also, supercritical CO 2 can offer an interesting alternative for glycerol separation in the biodiesel purification step in a water-free process. In this context, the main goal of this work was to investigate the phase behaviour of binary and ternary systems involving CO 2 , a pure constituent of biodiesel ethyl palmitate and ethanol. Experiments were carried out in a high-pressure variable-volume view cell with operating temperatures ranging from (303.15 to 353.15) K and pressures up to 21 MPa. The CO 2 mole fraction ranged from 0.5033 to 0.9913 for the binary {CO 2 (1) + ethyl palmitate(2)} system and from 0.4436 to 0.9712 for ternary system {CO 2 (1) + ethyl palmitate(2) + ethanol(3)} system with ethyl ester to ethanol molar ratios of (1:6), (1:3), and (1:1). For the systems investigated, vapour-liquid (VL), liquid-liquid (LL) and vapourliquid-liquid (VLL) phase transitions were observed. The experimental data sets were successfully modeled using the Peng-Robinson equation of state with the classical van der Waals quadratic (PR-vdW2) and Wong-Sandler (PR-WS) mixing rules. The PR-WS showed good performance in the prediction of the phase transition for the ternary systems based on the binary system data.
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.
J. Chem. Eng. Data, 2011
VaporÀliquid equilibria (VLE) data at (333.2, 343.2, 363.2, and 373.2) K and pressures between (1.1 and 14.1) MPa and critical data (pressureÀtemperatureÀcomposition) at pressures between (9.1 and 13.9) MPa for the carbon dioxide + ethanol system are reported. The experimental method used in this work was a static analytical method with liquid phase sampling using a rapid online sampler injector (ROLSI) coupled to a gas chromatograph (GC) for analysis. 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-parameter conventional mixing rule, 2PCMR) mixing rules. A single set of interaction parameters, representing the critical pressure maximum (CPM) well, was used in this work to represent the new VLE data and critical points and to predict the densities of the mixtures in a wide range of temperature, pressure, and composition. The calculation results were compared to the new data reported in this work and to available literature density data. The results show a satisfactory agreement between the model and 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).
Solubility data of a mixture containing 80.52 % ethanol and 19.48 % octane was measured in carbon dioxide solvent using a high-pressure type phase equilibrium apparatus at pressures up to 100 bar and at temperature of 75 °C. The experimental results showed that considerable separation was not achieved in this ethanol and octane ratio using carbon dioxide. From the point of view of the phase diagram for the current ternary system, the experimental results showed a closed loop. There was a two-phase region (vapor-liquid) in area (1) for ethanol-octane and CO 2 mixture. Furthermore, there was a one-phase region (liquid phase) in area (2) for the studied mixture. There also was a one-phase region (vapor phase) in area (3) for current mixture. According to the ethanol mole fractions extracted from the ternary system was investigated no effect of pressure on the solvent-free molar fraction of ethanol in both, the vapor and liquid phases. equilibria Many researchers have proven that carbon dioxide is chemically reactive toward alcohols, general oxygen-containing compounds and it also produces weak complexation in condensed mixtures of these substances . However, percentage of octane and ethanol extraction by high pressure CO 2 solvent increases with a decrease of pressure in the binary systems of CO 2 -octane and CO 2ethanol respectively, but extraction percentage of ethanol is more than octane at the same conditions . Furthermore, the azeotrope of the ethanol-octane systems occurs at around a ratio of ethanol: octane = 84: 16 [4], similar to the chosen ethanol-octane ratio in this study.
High-Pressure Phase Equilibria for the Carbon Dioxide + 1-Propanol System
Journal of Chemical & Engineering Data, 2008
High-pressure vapor-liquid equilibria (VLE) are measured for binary mixtures of carbon dioxide + methanol and carbon dioxide + isopropanol systems. Isothermal (P-x) data are presented for carbon dioxide + methanol at 298.15 and 310.15 K and pressures up 7.6 MPa. VLE data are also reported for the carbon dioxide + isopropanol system at 317.15 K and pressures up to 8.06 MPa. The phase equilibrium apparatus used in this work was a variable volume visual cell. The results were correlated with various equations of state and mixing rules.
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.
Solubility of CO2 in some heavy alcohols and correlation of fluid phase equilibrium
Fluid Phase Equilibria, 2003
The synthetic method was applied to measure the phase equilibrium of binary mixtures involving CO 2 and the following alcohols: undecan-2-ol, undecan-6-ol, undec-10-en-1-ol, and 2-methylpentan-2,4-diol. Measurements were performed at three different temperatures: 313.15, 323.15, and 333.15 K. The bubble points were measured at carbon dioxide mole fractions between 0.1 and 0.8 and at a pressure range of 13-160 bar. The results were correlated with the Peng-Robinson equation of state using the quadratic mixing rules.