Equilibrium Data For Binary Systems Research Articles

Simulation of Organic Liquid Products Deoxygenation by Multistage Countercurrent Absorber/Stripping Using CO2 as Solvent with Aspen-HYSYS: Thermodynamic Data Basis and EOS Modeling.

In this work, the thermodynamic data basis and equation of state (EOS) modeling necessary to simulate the fractionation of organic liquid products (OLP), a liquid reaction product obtained by thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na2CO3 as catalyst, in multistage countercurrent absorber/stripping columns using supercritical carbon dioxide (SC-CO2) as solvent, with Aspen-HYSYS was systematically investigated. The chemical composition of OLP was used to predict the density (ρ), boiling temperature (Tb), critical temperature (Tc), critical pressure (Pc), critical volume (Vc), and acentric factor (ω) of all the compounds present in OLP by applying the group contribution methods of Marrero-Gani, Han-Peng, Marrero-Pardillo, Constantinou-Gani, Joback and Reid, and Vetere. The RK-Aspen EOS used as thermodynamic fluid package, applied to correlate the experimental phase equilibrium data of binary systems OLP-i/CO2 available in the literature. The group contribution methods selected based on the lowest relative average deviation by computing Tb, Tc, Pc, Vc, and ω. For n-alkanes, the method of Marrero-Gani selected for the prediction of Tc, Pc and Vc, and that of Han-Peng for ω. For alkenes, the method of Marrero-Gani selected for the prediction of Tb and Tc, Marrero-Pardillo for Pc and Vc, and Han-Peng for ω. For unsubstituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of Tb, Marrero-Gani for Tc, Joback for Pc and Vc, and the undirected method of Vetere for ω. For substituted cyclic hydrocarbons, the method of Constantinou-Gani selected for the prediction of Tb and Pc, Marrero-Gani for Tc and Vc, and the undirected method of Vetere for ω. For aromatic hydrocarbon, the method of Joback selected for the prediction of Tb, Constantinou-Gani for Tc and Vc, Marrero-Gani for Pc, and the undirected method of Vetere for ω. The regressions show that RK-Aspen EOS was able to describe the experimental phase equilibrium data for all the binary pairs undecane-CO2, tetradecane-CO2, pentadecane-CO2, hexadecane-CO2, octadecane-CO2, palmitic acid-CO2, and oleic acid-CO2, showing average absolute deviation for the liquid phase () between 0.8% and 1.25% and average absolute deviation for the gaseous phase () between 0.01% to 0.66%.

Thermodynamic Consistency Test of Vapor–liquid Equilibrium Data of Binary Systems Including Carbon Dioxide (CO2) and Ionic Liquids Using the Generic Redlich–Kwong Equation of State

The thermodynamic consistency test of solubility P–T–x data for binary mixtures including carbon dioxide (CO2) + a room temperature ionic liquid has been investigated. Experimental solubility data taken from the open literature for 32 binary mixtures of CO2/RTILs contains 80 isotherms. The applied consistency test is based on the fundamental Gibbs–Duhem equation with use of the generic Redlich–Kwong (GRK) equation of state (EoS) coupled with the van der Waals–Berthelot (GRK/vdWB) mixing rule. The optimum parameters were obtained by minimizing the summation of per cent relative deviations between modeled and experimental data, based on the bubble pressure algorithm. Modeling was found acceptable for all isotherms, which demonstrated the usability of the GRK equation of state. Results of the thermodynamic consistency test showed that 36 of the isothermal data sets were thermodynamically consistent, 37 were not fully consistent, 6 were thermodynamically inconsistent and only one data set was found to need another model.

Measurement and correlation of vapor–liquid equilibrium data for binary systems composed of camphene, (+)-3-carene, (-)-β-caryophyllene, p-cymene, and α-pinene at 101.33 kPa

Isobaric vapor-liquid equilibrium (VLE) data have been measured in a modified Ellis still for the following binary systems: camphene + p-cymene, camphene + α-pinene, (+)-3-carene + α-pinene, α-pinene + (-)-β-caryophyllene, and camphene + (-)-β-caryophyllene, at 101.33 kPa. The pressure was controlled by a U-shape mercury manometer and a WT3000 intelligent absolute pressure transmitter. The thermodynamic consistency of the VLE experimental data was checked using the Herington area test and Van Ness test. Afterwards, the VLE data were correlated by the nonrandom two-liquid (NRTL), Wilson and universal quasichemical (UNIQUAC) activity coefficient models, with the corresponding binary interaction parameters being regressed. The root mean square deviations of temperature (RMSD(T)) and vapor-phase mole fraction (RMSD(y)) are all less than 0.61 K and 0.0076, respectively. Additionally, the average absolute deviations of temperature (AAD(T)) and vapor-phase mole fraction (AAD(y)) are all less than 0.54 K and 0.0061, respectively. Hence, all of the aforementioned models are deemed to be suitable to calculate the VLE data of the binary systems. In addition, for camphene + (-)-β-caryophyllene system, NRTL shows the best fit. Across all the binary systems studied no azeotropic behavior was observed.

Vapour-liquid phase boundaries including the near critical regions of the (CO2 + styrene, CO2 + 1,4-dioxane, and CO2 + N,N-dimethylformamide) systems

Phase equilibrium data for binary system of (CO2 + styrene, CO2 + 1,4-dioxane, and CO2 + N,N-dimethylformamide) were measured at temperatures from 308.2 K to 353.2 K and at pressures up to 12 MPa by means of a variable-volume view cell phase equilibrium analyser (PEA). The isothermal phase boundary data include measured phase transition of bubble, dew, and near critical pressures. The experimental results were correlated by means of the Peng-Robinson equation of state in conjunction with the van der Waals one-fluid mixing rules. The new data obtained in this work serve to clarify the inconsistencies among the literature values.

Process simulation of organic liquid products fractionation in countercurrent multistage columns using CO2 as solvent with Aspen-Hysys

Fractionation of liquid phase products (OLP), obtained by thermal catalytic cracking of palm oil, simulated in multistage countercurrent absorber/stripping columns using SC-CO2 as solvent with Aspen-Hysys, at 333 K, 140 and 180 bar, and (S/F) = 12, 15, 17, 25, 30, 38. RK-Aspen EOS applied to correlate equilibrium data of binary systems (OLP)-i/CO2. Composition of OLP used to predict thermophysical properties and acentric factor of OLP compounds by group-contribution methods. The effect of pressure and (S/F) on process performance evaluated by computing the yield and recoveries of hydrocarbons, olefins, oxygenates, carboxylic acids. The regressions show that RK-Aspen EOS describe well phase equilibrium data, showing AAD between 0.8% and 1.25% and 0.01%– 0.66% for the liquid and gaseous phases. The best deacidifying conditions obtained at 333 K, 140 bar, and (S/F) = 17. Simulations show that SC-CO2 was able to deacidify OLP and to obtain fractions with lower olefins content.

Isobaric Vapor–Liquid Equilibrium Data for Binary Systems of Anisole with Methyl Acetate, Ethyl Acetate, n-Propyl Acetate, and Isopropyl Acetate at 93.9 kPa

The present work reports experimental isobaric vapor–liquid equilibrium data at 93.9 kPa pressure using a dynamic recirculation still for four binary pairs of acetates with anisole. The suitability of the experimental data for modeling was established by performing the Herington area test, Van Ness test, and mean absolute deviation test. Binary interaction parameters necessary for process modeling were derived through the regression of the VLE data for Wilson, NRTL, and UNIQUAC activity coefficient models with a suitable objective function. VLE data in the form of T–x, y plots indicates no formation of azeotropes for all pairs.

Optimizing Thermodynamic Models: The Relevance of Molar Fraction Uncertainties

Parameters contained in thermodynamic models are usually optimized over vapor–liquid equilibrium data of binary systems, applying methods that enable consideration of the uncertainty of experimental data, such as the Maximum Likelihood Method (MLM). However, authors of these data generally indicate only the maximum or average uncertainty associated with an overall set of data. Specific uncertainties, associated with each measurement, are rarely mentioned. As a consequence, the optimization of models by, for example, MLM is usually performed by associating constant overall uncertainty values to data points, instead of their specific values. This paper aims to show that results obtained from the application of MLM are strongly affected by the use of constant rather than specific uncertainties. In particular, the optimization of models over highly nonideal high-pressure vapor–liquid equilibrium data is strongly affected by the uncertainty of molar fractions, rather than by the uncertainty of pressure and tem...

VAPOUR-LIQUID EQUILIBRIUM IN SYSTEMS WITH ISOBUTYL ACETATE, ACETIC ACID AND METHYL ETHYL KETONE

The experimental temperature dependence of the vapour pressures of isobutyl acetate, acetic acid and methyl ethyl ketone were determined, and isobaric vapour-liquid equilibrium data of binary systems of methyl ethyl ketone + isobutyl acetate and methyl ethyl ketone + acetic acid were obtained. The experimental data were processed using the Antoine and Riedel equations and the NRTL and Wilson local composition equations, respectively. Comparison of the experimental and calculated data confirmed the adequacy of the vapour-liquid equilibrium mathematical simulation.

Vapor–Liquid Equilibrium Data for Binary Systems of N,N-Dimethylacetamide with Cyclohexene, Cyclohexane, and Benzene Separately at Atmospheric Pressure

The reaction for hydrogenation of benzene has been paid much attention as the demand for synthesis of nylon rapid developa. Usually, byproducts of cyclohexane and unreacted benzene unavoidably exist in the production of cyclohexene through the hydrogenation of benzene route. To obtain cyclohexene with high purity, extractive distillation is used to separate cyclohexene mixture. However, the process simulation for extractive distillation is necessary for industry design and production, which requires the relevant vapor–liquid equilibrium (VLE) data to simulate accurately. The VLE data for the binary systems of extractant N,N-dimethylacetamide (DMAC) with cyclohexene, cyclohexane, and benzene at atmospheric pressure was measured using a PH-I-type VLE kettle. In addition, a thermodynamic consistency check has been done on the obtained data, indicating that the experimental data satisfy the examination of the thermodynamic consistencies. Moreover, the results are significantly close when NRTL and Wilson equat...

Measurement and Modeling for Isobaric Vapor–Liquid Equilibrium of Binary 1,3,5-Trichlorobenzene + 3,5-Dichloroaniline and 3-Chloroaniline + 3,5-Dichloroaniline Systems

The isobaric vapor–liquid equilibrium data for binary systems of 1,3,5-trichlorobenzene (1) + 3,5-dichloroaniline (2) and 3-chloroaniline (1) + 3,5-dichloroaniline (2) were measured experimentally under pressures of 20.00, 60.00 and 101.20 kPa using an inclined ebulliometer. Thermodynamic consistency of the vapor–liquid equilibrium data was tested by means of the Herington semiempirical method, and the isobaric vapor–liquid equilibrium data were correlated with three activity coefficient models, which were Wilson, NRTL and UNIQUAC. The energy interaction parameters were acquired by a nonlinear least-squares regression method for the three thermodynamic models. Results indicate that all the three activity coefficient models can describe the measured isobaric vapor–liquid data acceptably. The isobaric vapor–liquid equilibrium data determined in the present work are important in the design and operation for purification of 3,5-dichloroaniline by distillation.

Saturated vapor pressure of 4-fluorophthalic anhydride and 4-chlorophthalic anhydride and isobaric vapor–liquid phase equilibrium of 4-fluorophthalic anhydride + 4-chlorophthalic anhydride: Measurement and modeling

The saturated vapor pressures of 4-fluorophthalic anhydride and 4-chlorophthalic anhydride at various temperatures ranging from T=(426 to 560)K, and the isobaric vapor–liquid phase equilibrium data for binary system of 4-fluorophthalic anhydride (1)+4-chlorophthalic anhydride (2) at pressures of 21.33kPa, 41.33kPa, 61.33kPa and 81.33kPa were measured experimentally by means of an inclined ebulliometer. The relationship between saturated vapor pressure and temperature was fitted by using two Antoine equations and the Antoine constants were acquired for 4-fluorophthalic anhydride and 4-chlorophthalic anhydride, respectively. The semi-empirical method, Herington method was employed to test thermodynamic consistency of the vapor–liquid equilibrium data. The isobaric vapor–liquid phase equilibrium data were fitted with three thermodynamic models, which corresponded to Wilson, NRTL and UNIQUAC. The parameters of the three activity coefficient models were obtained by the method of nonlinear least-square regression. The calculated vapor–liquid phase equilibrium data with the three activity coefficient models agree very well with the experimental values.

Isothermal Vapor–Liquid Equilibrium Data and Thermodynamic Modeling for Binary Systems of Perfluorobutane (R610) + (Methane or Hydrogen Sulfide) at (293, 313, and 333) K

Isothermal vapor–liquid equilibrium data for binary systems comprising perfluorobutane (R610) with methane (CH4) or hydrogen sulfide (H2S) were measured at isothermal conditions of approximately (293, 313, and 333) K, and pressures up to 9.837 MPa. The data were measured using a “static-analytic” apparatus equipped with a mobile pneumatic capillary sampler. The experimental data were correlated via the direct method using two sets of thermodynamic models. The Peng–Robinson equation of state incorporating the Mathias–Copeman α function, with the Wong–Sandler mixing rule utilizing the nonrandom two-liquid activity coefficient model, was used for the correlation of the CH4 + C4F10 system, while the Soave–Redlich–Kwong equation of state incorporating the Mathias–Copeman α function, with the modified Huron–Vidal first-order mixing rule utilizing the nonrandom two-liquid activity coefficient model was used for the H2S + C4F10 system.

Modeling the Phase Behavior of Essential Oils in Supercritical CO2 for the Design of a Countercurrent Separation Column

This work describes a generalized procedure for high pressure equilibrium calculations for terpene oils. A simple semiempirical model allows the prediction of the solubilities of essential oils at high pressure on the basis of the physicochemical properties of their compounds (molecular weight, boiling temperature, density, and solubility parameter). This easy model can be useful for the determination of the fractionation and for the preliminary scale-up and economic evaluation. The theoretical basis considers any essential oil composed of two types of components: oxygenated and nonoxygenated. Vapor–liquid equilibrium data of binary systems (terpenoids/CO2) are used to correlate the semiempirical model proposed. Validity of the prediction is checked by comparison with literature data concerning ternary systems (limonene + linalool + CO2) and real mixtures (lemon and orange oils + CO2). Finally, the simulation and optimization of a countercurrent column for the fractionation of terpenes from lemon oil are ...

Isobaric Vapor–Liquid Equilibrium Data for Binary System of Glycerol Ethyl Acetal and Acetonitrile at 60.0 kPa and 97.8 kPa

Isobaric vapor–liquid equilibrium (VLE) data for the binary mixture of glycerol ethyl acetal (GEA) and acetonitrile were measured at 60.0 kPa and 97.8 kPa, using a dynamic recirculating still. The VLE data were correlated using the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) models, and the interaction parameters of this mixture were estimated. The experimental procedure was checked by measuring VLE data at 97.8 kPa of the well-known system acetone/methanol showing high conformity, as given by applying a set of VLE consistency tests. The vapor pressure of GEA was measured, for the first time, in the temperature range from 371.85 K to 456.85 K, and it is described by the following expression: ln PGEAsat(Pa) = 24.17 – 5781/T(K). The information collected is of utmost importance for the purification of GEA synthesized using simulated moving bed reactor technology.

Correlation of liquid-liquid equilibria of non-ideal binary systems by NRTL model

Non Random Two Liquid model (NRTL) with three different forms of temperature dependant parameters was used to correlate the liquid - liquid equilibrium data for systems of alcohols with alkanes, and alcohols with two ionic liquids: 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([bmmim][BF4]) and 1-butyl-3-ethylimidazolium tetrafluoroborate ([beim][BF4]). Different temperature dependences of NRTL parameters were tested on thirteen literature experimental liquid - liquid equilibrium data for binary systems.

Vapor–Liquid Equilibrium Data for Binary Systems of 1H-Pyrrole with Butan-1-ol, Propan-1-ol, or Pentan-1-ol

Isobaric and isothermal vapor–liquid equilibrium (VLE) data are presented for binary systems comprising 1H-pyrrole (pyrolle) with light alcohols. The systems measured include 1H-pyrrole + butan-1-o...

Phase equilibrium measurements and thermodynamic modeling of methane alcohol systems at ambient temperature

The (vapor+liquid) equilibrium data for binary systems of (methane+methanol), (methane+ethanol), and (methane+1-propanol) at ambient temperature over a wide range of pressures, (1 to 8)MPa, were measured using a designed pressure–volume–temperature (PVT) apparatus. The phase composition and saturated density of liquid phase were measured for each pressure. The density of pure methanol, ethanol and 1-propanol was also measured at ambient temperature over a wide range of pressure (1 to 10)MPa. The experimental (vapor+liquid) equilibrium data were compared with the modeling results obtained using the Peng–Robinson and Soave–Redlich–Kwong equations of state. To improve the predictions, the binary interaction parameters were adjusted and the volume translation technique was applied. Both equations of state were found to be capable of describing the phase equilibria of these systems over the range of studied conditions. The Soave–Redlich–Kwong equation of state gave better predictions of saturated liquid densities than Peng–Robinson equation of state.

Particle swarm modeling of vapor-liquid equilibrium data of binary systems containing CO2 + imidazolium ionic liquids based on bis[(trifluoromethyl)sulfonyl]imide anion

Based on particle swarm optimization (PSO), a thermodynamic modeling for the vapor-liquid equilibrium of binary mixtures of carbon dioxide with ionic liquids is presented. The Peng-Robinson equation of state with the Wong-Sandler mixing rules is used to evaluate the fugacity coefficient of the systems. Simulations are carried out in five systems containing 1-alkyl-3-methylimidazolium ionic liquids based on bis[(trifluoromethyl)sulfonyl]imide anion. Then, PSO algorithm was used to minimize the difference between calculated and experimental bubble pressure, and calculate the interaction parameters and the excess Gibbs free energy for all systems used. The results show that the bubble pressures were correlated with low deviations between experimental and calculated values. These deviations show that the PSO algorithm is the preferable method to optimize the interaction parameters of the phase equilibria of binary systems of supercritical carbon dioxide with ionic liquids, and can be used for other similar systems.

(Liquid + liquid) equilibrium for binary systems of N-formylmorpholine with alkanes

(Liquid + liquid) equilibrium (LLE) data were determined for four binary systems containing N-formylmorpholine (NFM) and alkanes (3-methylpentane, heptane, nonane, and 2,2,4-trimethylpentane) over the temperature range from around 300 K to near 420 K using a set of newly designed equilibrium equipment. The compositions of both light and heavy phases were analyzed by gas chromatography. The mutual solubility increased as the temperature increased for all these systems. The binary (liquid + liquid) equilibrium data were correlated by the NRTL and UNIQUAC equations with temperature-dependent parameters. Both models correlate the experimental results well. Furthermore, the UNIFAC (Do) group contribution model was used to correlate and estimate the LLE data for NFM containing systems. Two methods of group division for NFM were used. NFM is treated as a single group: NFM group (method I) or divided into two groups: CHO and C 4H 8NO (method II), respectively. The group interaction parameters for CH 2–NFM, or CH 2–CHO and CH 2–C 4H 8NO were fitted from the experimental LLE data. The UNIFAC (Do) model correlates the experimental data well. In addition, in order to develop UNIFAC (Do) group contribution model to estimate the LLE data of (NFM + cycloalkane) systems, some literature LLE data were used. The group interaction parameters for c-CH 2–NFM, c-CH 2–CHO and c-CH 2–C 4H 8NO were correlated. Then these group interaction parameters were used to estimate the phase equilibrium data of binary systems in the literature by the UNIFAC (Do) model. The results showed that the estimated values are in good agreement with the literature data. In contrast, the method I is better than the method II. This shows that treating NFM as a single NFM group is more reasonable, and the fitted parameters are satisfactory for designing the aromatic recovery process with NFM as solvent.

(Vapor + liquid) equilibrium properties of (ethane + ethanol) system at (295, 303, and 313) K

The (vapor+liquid) equilibrium data for binary system of (ethane+ethanol) at three temperatures (295, 303, and 313)K were measured using a designed pressure–volume–temperature (PVT) apparatus. A wide range of pressures, (1 to 5)MPa, were considered for the measurements. The phase composition, saturated density, and viscosity of liquid phase were measured for each pressure and temperature. The experimental (vapor+liquid) equilibrium data were compared with the modeling results obtained using the Peng–Robinson and Soave–Redlich–Kwong equations of state.