Binary System Carbon Dioxide Research Articles

High-pressure phase equilibrium data for the binary system carbon dioxide and ε-caprolactone

High-pressure phase equilibrium data for the binary system carbon dioxide and ε-caprolactone

Vapor–Liquid Equilibrium Phase Behavior of Binary Systems of Carbon Dioxide with Eugenol or Guaiacol

Vapor–Liquid Equilibrium Phase Behavior of Binary Systems of Carbon Dioxide with Eugenol or Guaiacol

Excess molar enthalpies in the binary system of carbon dioxide + ethyl lactate at 298.15 and 303.15 K and 5.0–7.0 MPa

This paper presents an experimental determination of the excess molar enthalpies (HE) for the binary system of carbon dioxide (CO2) + ethyl lactate at temperatures of 298.15 and 303.15 K and pressures in the range of 5.0–7.0 MPa. A maximum exothermic value of approximately 7.4 kJ mol−1 was found, similar to the exotherms observed in our previous work for other binary systems such as CO2 + ester or ether. We discussed this exothermic behavior based on the change-of-state contribution, strong CO2-ester interactions, and unusual intra- and intermolecular hydrogen bonding of ethyl lactate. The experimental HE data correlated well with a composition-dependent equation and the Peng–Robinson equation of state with the van der Waals one-fluid mixing rule.

Vapor Equilibrium Data for the Binary Mixtures of Dimethyl Carbonate and Ethyl Methyl Carbonate in Compressed Carbon Dioxide

Phase equilibrium data (p, T, y) for the binary systems of carbon dioxide + dimethyl carbonate and carbon dioxide + ethyl methyl carbonate were obtained. All systems were measured for isotherms ranging from 298.2 K to 328.2 K with pressure ranging between 0.13 MPa and 10.6 MPa. A static equilibrium technique was established with samples quantified using an offline method. The results were modeled using the Peng–Robinson equation of state with van der Waals one-fluid mixing rules.Graphical

Vapor-liquid equilibrium phase behavior of binary systems of carbon dioxide with dimethyl adipate or monomethyl adipate

The vapor–liquid equilibria (VLE) phase boundary data were measured for the binary systems of carbon dioxide + dimethyl adipate (DMA) and carbon dioxide + monomethyl adipate (MMA) at 313.15 K, 333.15 K, 353.15 K, and 373.15 K and pressures up to 29 MPa. A visual and variable-volume phase equilibrium analyzer (PEA) was employed to observe the phase transition over the whole composition range. The vapor-liquid equilibrium ratios (K-values) and the critical points have been estimated from the VLE phase boundary data. The new VLE data obtained from this work were correlated with the Soave-Redlich-Kwong (SRK) and the Peng-Robinson (PR) equations of state incorporating with the two-parameter van der Waals one-fluid mixing rules (vdW2). The PR equation of state yields better results and the average absolute pressure deviations are lower than 4 %.

VLE property measurements and PC-SAFT/ CP- PC-SAFT/ E-PPR78 modeling of the CO2 + n-tetradecane mixture

This paper presents a new experimental VLE property data in the binary system of carbon dioxide – n -tetradecane at three selected isotherms of 313.15 K, 333.15 K, and 353.15 K in the pressure range from (3.8 to 19.0) MPa. The measurements were made using a high-temperature and high-pressure optical cell. The standard absolute u and relative u r uncertainties of temperature, pressure, concentration measurements are: u ( T ) =7.5 mK; u r ( P ) =0.00025; u r ( x ) =0.015; and u r ( y ) =0.015. The measured VLE data were used to determine the critical P C - T C curve data. Based on the derived values of the critical parameters of CO 2 + n -tetradecane mixture the value (-67.58 MPa) of the Krichevskii parameter has been determined. The predictive capabilities of the perturbed chain-statistical associating fluid theory (PC-SAFT), the critical point-based modification of PC-SAFT (CP-PC-SAFT), and the Enhanced -Predictive-Peng-Robinson-78 ( E -PPR78) models were examined.

Determination of Viscosity, Density and Interfacial Tension of the Carbon Dioxide–Isopropanol, Argon–Isopropanol, Sulphur Hexafluoride–Isopropanol Binary Systems at 313.15 K and 333.15 K and at Elevated Pressures

Viscosity, density, and interfacial tension of three binary systems (carbon dioxide–isopropanol, argon–isopropanol, and sulphur hexafluoride–isopropanol) were measured at temperatures of 313.15 K and 333.15 K and at pressures up to 100 bar for carbon dioxide, and for argon and sulphur hexafluoride up to 500 bar. A vibrating tube densimeter method has been used for density measurements and a variable-volume high-pressure optical view cell with some modifications for the other measurements. The results showed that pressure does not have a high impact on viscosity. Density is found to be a linear function of pressure and temperature and the densities of the investigated binary systems increase with pressure and decrease with temperature. Interfacial tension decreased with the elevated pressure at a constant temperature for all the investigated systems. Accurate prediction of thermodynamic and mass transfer data is fundamental in various engineering and industrial operations to design processes with a higher yield of targeted compounds.

Vapor-liquid equilibrium phase behavior of binary systems of carbon dioxide with dimethyl succinate or dimethyl glutarate

BackgroundTo develop process for separating dimethyl succinate (DMS) and dimethyl glutarate (DMG) with the aid of supercritical carbon dioxide, the vapor-liquid equilibrium (VLE) data of the related mixtures are fundamentally important. The VLE data were determined experimentally and correlated with various thermodynamic models in this study. MethodsThe isothermal VLE data were measured for carbon dioxide + DMS and carbon dioxide + DMG by using a semi-flow and a static types of apparatuses at temperatures from 313.15 K to 413.15 K and pressures up to 20 MPa. These VLE data were correlated with the Krichevsky-Ilinskaya (KI) equation, the Soave-Redlich-Kwong (SRK), the Peng-Robinson (PR) and the Patel-Teja (PT) equations of state incorporating with two-parameter one-fluid van der Waals mixing rules (vdW-2). Significant findingsThe results of this study provide the VLE data of carbon dioxide + DMS and + DMG and reveal the VLE phase transition behavior, especially crossing near critical region. The Henry's constant and critical loci were also estimated. The Peng-Robinson equation of state with the vdW-2 mixing rule yielded the best data correlation results. The optimal values of the binary interaction parameters were also obtained, which can be used in the separation process simulation and design.

Binary mixture phase equilibria for the vinyl laurate, vinyl methacrylate and vinyl propionate under high pressure carbon dioxide

The experimental phase equilibrium data of binary mixtures of vinyl laurate, vinyl methacrylate, and vinyl propionate in supercritical CO2 fluid is reported at high pressure starting from 3.92 MPa to 23.55 MPa and temperature varying from 313.2 K to 393.2 K with a static-type high pressure apparatus. It is observed that the solubility of binary mixtures considered in present study increases with temperature at constant pressure. Furthermore, at constant pressure, the critical point of the mixtures moves higher as temperature increases. Besides, the type I phase curve is exhibited by all the binary mixtures considered.The experimental bubble pressure data is correlated with Ghoderao-Dalvi-Narayan (GDN) and Peng-Robinson (PR) equations of state by the using Van der Waals single fluid mixing rules with two adaptable interaction factors. The pressure-composition (P-x) isotherms are obtained for the binary systems (carbon dioxide + vinyl laurate), (carbon dioxide + vinyl methacrylate), and (carbon dioxide + vinyl propionate) at several temperatures varying from 313.2 K to 393.2 K. A good fit to the experimental data is obtained with GDN equation of state performing better than PR equation of state.

Non-saturated mixture densities of the binary systems of carbon dioxide and the organic solvents ethanol, acetone, acetonitrile and dimethyl sulfoxide from 6-12 MPa

Mixture density data for the four binary systems consisting of carbon dioxide and the organic solvents ethanol, acetone, acetonitrile and dimethyl sulfoxide are reported. Composition dependent isobaric and isothermal mixture densities from 6−12MPa and 308−333K over the entire composition range in the single-phase region were acquired using a temperature conditioned Coriolis mass flow and density meter. The Non-Random Hydrogen Bonding model with a single, temperature independent binary interaction parameter was used to correlate the mixture density data. Modeled mixture densities showed an averaged deviation < 2% for each binary system. Extensive experimental data also enabled the estimation of the boiling point line of the binary systems within an interval of confidence of 0.05 mole fractions.

A new high pressure phase equilibrium cell featuring the static-combined method: Equipment commissioning and data measurement

A new equilibrium cell featuring a floating piston with an internal variable volume and phase sampling mechanism was designed and commissioned for the measurement of phase equilibrium data. The experimental technique can be extended to the static-combined method. The apparatus was tested by measuring vapor-liquid equilibrium data for the binary system of carbon dioxide + n-hexane at 313.15 K. New experimental vapor-liquid equilibrium data were also measured for the binary systems of carbon dioxide + 1,1,2,2 tetrafluoroethyl 2,2,3,3 tetrafluoropropyl ether at four temperatures, viz. (303.15, 313.15, 323.15 and 333.15) K and modeled using the Peng-Robinson Equation of State. Data close to the mixture critical points were modeled using a scaling law. The average expanded uncertainty for T, P, x1 and y1 for all systems in this work were 0.08 K, 0.002 MPa, 0.004 and 0.0007, respectively.

Prediction of Carbon Dioxide Solubility in Monoethylene Glycol /Water Mixtures Employing SRK and PR-EOS with Two Different Mixing Rules

A thermodynamic models of binary system carbon dioxide (1) - mixture (monoethylene glycol (MEG)/water) (2) at pressure up to 5 bar and temperatures (288-348 K) are established using SRK and PR equation of state (EOS). Modified van der Waal’s and quadratic mixing rules are coupled with the two Equation of state. Prediction of carbon dioxide in pure water and MEG were studied as well using same equations. Average absolute deviation in liquid-phase compositions percentage AADx % used for adjustable parameter optimization. The predicted results are showed very good agreement with the experimental data in all the systems examined. Quadratic mixing rule in all systems gives AADx % lower than Modified van der Waal’s and the values differences can be ignored.

Investigation of carbon dioxide capture and storage by a novel LSSVM-GA method

Accurate knowledge about vapor–liquid equilibrium (VLE) and phase behavior of impure carbon dioxide has noticeable effect on designing carbon dioxide capture and storage (CCS) processes. In the current work, a novel computational method namely least square support vector machine (LSSVM) was used to predict VLE of binary system of carbon dioxide with nitrogen, hydrogen, oxygen, and argon. To this end, two models based on LSSVM were developed for vapor and liquid phases. The accuracy of predicting models was investigated by different methods. The results express that the proposed algorithms are dependable for the estimation of phase behavior of impure CO2.

Excess molar enthalpies of the binary system carbon dioxide + butyl levulinate at 298.15 and 303.15 K and 5.0–7.0 MPa

The excess molar enthalpies (HE) of the binary system carbon dioxide (CO2) + butyl levulinate (a solvent obtainable from biomass) were determined near the critical point of CO2, using a flow-type isothermal microcalorimeter. Values are reported for temperatures of 298.15 and 303.15 K and pressures in the range of 5.0–7.0 MPa. A maximum exothermic value of approximately 8.1 kJ mol−1 was determined, similar to the significant exotherms observed in our previous work for other binary systems. The experimental HE data were well correlated with a composition-dependent equation and the Peng-Robinson equation of state in conjunction with the conventional mixing rule.

PHASE BEHAVIOR DATA AND THERMODYNAMIC MODELING OF THE BINARY SYSTEM {CO2 + COUMARIN} AT HIGH PRESSURES

Abstract In this work, vapor - liquid (VLE) equilibrium for the binary system carbon dioxide (1) + coumarin (2) at high pressures was measured by a static synthetic method using a variable-volume view cell. Experimental data were obtained in the temperature range of 318 - 338 K and pressures up to 20 MPa. Coumarin molar fraction ranged from 3.0x10-3 to 6.0x10-3. Coumarin melting point reduction at high pressures was observed. The experimental results were modeled using the Peng-Robinson (PR) equation of state with van der Waals quadratic mixing rules (vdW - QMRs), providing a good representation of the experimental phase equilibrium data. Critical properties and the acentric factor were estimated using the Constantinou and Gani method, which showed to be satisfactory on the quality of data correlation. Results indicate coumarin solubility increases with increasing phase transition pressure at a given temperature.

High-Pressure Vapor−Liquid Equilibria of 1-Alkyl-1-Methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids and CO2

The high-pressure vapor–liquid equilibrium for the binary systems of carbon dioxide (CO2) and a series of 1-alkyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids ([CnC1pyr][N...

VLE measurements and modelling for the binary systems of (CF4 + C6F14) and (CF4+ C8F18)

Isothermal phase equilibrium data were measured for the binary systems of tetrafluoromethane with either perfluorohexane or perfluorooctane to investigate the effect of carbon chain length of the solvent with regards to the solubility of tetrafluoromethane. Both the “static-analytic” and the “static-synthetic” methods were utilized to measure the high-pressure phase equilibrium data. Isothermal measurements were performed within the temperature range of (283.15–303.15) K and at pressures up to 11 MPa. Vapour pressure data for perfluorohexane and perfluorooctane were measured within the temperature range of (283.15–323.15) K. Additionally, isothermal vapour-liquid equilibrium data were measured for the binary system of carbon dioxide + n-hexane at 313.15 K; the data were utilized to validate the experimental method. The experimental data were modeled using the Peng-Robinson equation of state with the Wong-Sandler mixing rule and Non-Random Two-Liquid excess Gibbs energy model. The model provides a satisfactory representation of the experimental data within the measured temperature range.

High pressure phase equilibrium data for carbon dioxide, methyl methacrylate and poly (dimethylsiloxane) systems

This paper investigates high-pressure phase transitions for the binary system carbon dioxide (CO2) + methyl methacrylate (MMA) and for the ternary system CO2 + MMA + poly (dimethylsiloxane) vinyl terminated (PDMS-V). The experiments were carried out using the static-synthetic method in a stainless steel equilibrium cell with a variable-volume, including piston and sapphire window, at temperatures of 323.15, 333.15, 343.15 and 353.15 K and the molar fraction ranging from 0.6949 to 0.9499 and 0.6833 to 0.9444 for the binary and ternary systems, respectively. For the binary system, phase transition was determined from the liquid region to the two-phase region. High miscibility of carbon dioxide in MMA was observed with a significant volumetric expansion of the liquid phase. The surfactant PDMS-V was added to this binary system in order to investigate its effect on the phase behavior. For the ternary system CO2 + MMA + PDMS-V, phase transitions were observed from the liquid homogeneous phase until the two-phase region. The results indicate that the addition of PDMS-V led to a small increase in the phase transition pressure, and for the liquid-liquid region a large increase in the phase transition pressure of the system occurred at all temperatures.

Three-Phase Melting Curves in the Binary System of Carbon Dioxide and Water

Invariant, three-phase melting curves, of ice VI in equilibrium with solid CO2, of ice VII in equilibrium with solid CO2, and of solid CO2 in simultaneous equilibrium with a majority aqueous and a majority CO2 fluid, were explored in the binary system of carbon dioxide and water. Diamond-anvil cells were used to develop pressures of 5 GPa. Water exhibits a large melting temperature depression (73°C less than its pure melting temperature of 253°C at 5 GPa) indicative of large concentrations of CO2 in the aqueous solution. The melting point of water-saturated CO2 does not show a measureable departure from that of the pure system at temperatures lower than ∼200°C and only 10°C at 5 GPa (from 327°C).

Phase equilibrium and critical point data for ethylene and chlorodifluoromethane binary mixtures using a new “static-analytic” apparatus

An apparatus based on the “static-analytic” method was designed and commissioned. The apparatus was tested by measuring vapour-liquid equilibrium data for the binary system of carbon dioxide + chlorodifluoromethane at 273.15 K. There is excellent agreement between the experimental data and previous measurements reported in the literature. New experimental vapour-liquid equilibrium data were also measured for the binary systems of ethylene + chlorodifluoromethane at five temperatures, viz. (273.15, 293.15, 313.15, 333.15, and 353.15) K. At the same temperatures (excluding 273.15 K) the critical points of the binary mixtures were also experimentally determined. The experimental data for this binary system were accurately correlated using the Peng–Robinson Equation of State utilizing the Wong–Sandler mixing rule coupled with the Non-Random Two-Liquid (NRTL) activity coefficient model.