Values Of Binary Interaction Parameters Research Articles

The integrative approach of learning chemical engineering thermodynamics by using simulation-based exercises

The active learning integrative approach of simulation-based exercises along with the core course would help undergraduate students with more engaged learning. The present study describes the simulation approach using an open-source process simulator with the help of three simulation-based exercises. The first one exemplifies the importance of the selection of an appropriate fluid package. The second exercise presented in the study shows the effect of using optimized and default values of binary interaction parameters on VLE prediction of alcohol-ester systems. The small interactive simulation-based problems with expected outcomes were presented in the third exercise which makes the learning more engaging and interesting. The current study highlights an integrative approach to inculcating critical thinking and self-learning abilities using small simulation-based exercises while learning chemical engineering thermodynamics. Finally, a survey with closed- and open-ended questions was used to gather the opinions of students on the presented exercises. A short communication is needed that sheds light on the integrative approach of learning process simulation complementing the thermodynamic theory learning.

Liquid–liquid equilibria of the ternary system (cyclopentanol + water + cyclopentyl formate) at (298.2–338.2) K: Measurements and correlation

Cyclopentanol is an important intermediate in a production of many chemical specialties. This paper relates to a development of a new technology of indirect cyclopentene hydration in the presence of formic acid and presents the data of liquid-liquid equilibrium (LLE) for the ternary system of (cyclopentanol + water + cyclopentyl formate) under atmospheric pressure and within a temperature range from 298.2 K to 338.2 K. The experiments were conducted in a temperature-controlled glass cell and the received data were correlated with nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) equations in order to obtain binary coefficients describing LLE of the given system. A consistency of the experimental tie-lines data was validated by the Bachman and Othmer-Tobias equations and the data fitting accuracy was evaluated by the use of the calculated average absolute deviation and the root-mean-square-error values. According to our best knowledge, the LLE of this system have not yet been published elsewhere and the values of binary interaction parameters should be used for the design of the reactor and separation units in the process of indirect cyclopentene hydration.

Vapor–Liquid Equilibrium Prediction of Refrigerant Mixtures with Peng–Robinson Equation of State and Binary Interaction Parameters Calculated Through Group Contribution Model

Vapor–liquid equilibrium (VLE) properties of refrigerant mixtures are essential to the analysis of thermodynamic cycle performance. The accurate value of binary interaction parameter (kij) for classical Van der Waals (VDW) mixing rules is highly significant for the VLE prediction of mixtures. Therefore, in this contribution, a theoretical correlation for kij is derived as a function of the activity coefficients, which are obtained from the group contribution model UNIFAC. So that, the widely applied Peng–Robinson equation of state with the VDW mixing rule can be predictable for any refrigerant mixtures, according to the existing group contribution values. 18 alternative refrigerant mixtures and two GE models, namely MHV1 and WS are used to exhibit the capacities and limitations of the proposed VDW. The calculated results show that the developed VDW can correlate the VLE experimental data well in most cases. Compared with the MHV1 and WS, the proposed model has better VLE prediction, especially for HFCs + HFCs/HFOs mixtures. Thereafter, VLE of 6 refrigerant mixtures are obtained by GC-VTPR. The comparison shows that the accuracy of VDW model is comparable with that of GC-VTPR. Furthermore, mixture densities at different temperatures and pressures are predicted by the developed VDW and GC-VTPR. Results show that GC-VTPR has better density prediction than VDW and the largest deviation of VDW between predicted results and experimental data is 7.04% for R125 + R143a.

A comprehensive description of single-phase and VLE properties of cryogenic fluids using molecular-based equations of state

A complete description of fluid-phase thermodynamic properties at cryogenic conditions undoubtedly presents a serious challenge for equations of state (EOSs). This work is focused on comparing the capabilities of two Statistical Associating Fluid Theory-based EoSs, namely PC-SAFT, SAFT + Cubic, and one cubic model, the original PR EOS, in correlating and predicting various thermodynamic properties of 14 main cryogenic fluids (noble gases, light hydrocarbons, nitrogen, oxygen, carbon dioxide, carbon monoxide, and nitrous oxide). Additionally, the available low temperature vapor-liquid equilibrium (VLE) data of their binary and ternary mixtures are also evaluated in this comparative study. It has been found that, apart from the critical and near-critical data, PC-SAFT has a clear advantage in modeling the pure compound properties such the sound velocity and density (with the overall AADs% less than 7%). Nevertheless, the overestimation of the single phase properties in low temperature and high pressure regions and the poor accuracy in modeling the high pressure VLE compositions of binary mixtures are two major drawbacks of PC-SAFT. SAFT + Cubic is less accurate in predicting pure compound properties; however, having small values of binary interaction parameters, it is slightly more accurate than PC-SAFT in modeling various VLE isotherms of mixtures in a predictive manner (with the overall AADs around 3%). At the same time, PR EOS exhibits the most significant deviations from the low temperature experimental data of both pure cryogens and their mixtures. However, it yields particularly accurate predictions of isochoric heat capacities in the liquid phase.

Measurement and thermodynamic modelling of ternary liquid-liquid equilibrium for extraction of (1R,2R)-(−)-1,2-Diaminocyclohexane from aqueous solution with C4–C5 alcohols at different temperatures

Abstract (Liquid + liquid) equilibrium data for the ternary systems of {(2-Methyl-1-propanol or 3-Methyl-1-butanol) + (1R,2R)-(−)-1,2-Diaminocyclohexane + water} were measured at (288.2–318.2) K under atmospheric pressure. The Othmer-Tobias and Hand equations were employed to verify the reliability of the experimental data. Besides, the distribution coefficients and selectivity factors calculated from the experimental tie-line data were applied to evaluate the extraction performance of separating (1R,2R)-(−)-1,2-Diaminocyclohexane from aqueous solution and 3-Methyl-1-butanol was proved to be very promising. Furthermore, the binary interaction parameter values were obtained by correlating the experimental data with NRTL and UNIQUAC models. All the RMSD values were less than 0.0184, indicating that both models can be used to describe the liquid-liquid equilibrium behaviour of the studied systems.

Measurement and thermodynamic modelling of ternary liquid-liquid equilibrium for extraction of thioglycolic acid from aqueous solution with different solvents

Liquid-liquid equilibrium (LLE) data for the ternary systems {water+thioglycolic acid+(butyl acetate, isobutyl acetate or isopropyl acetate)} were determined at 293.15K and 101.3kPa. The solubility values were obtained by using the titration method. Moreover, the Hand and Othmer-Tobias equations were applied to validate the reliability of the obtained LLE values, and the distribution coefficients and separation factors were calculated to evaluate the solvents performances to extract thioglycolic acid from aqueous solution. The results indicate that isobutyl acetate is the best among the organic solvents studied for the separation of thioglycolic acid from aqueous solution. The thermodynamic NRTL and UNIQUAC models were used to correlate the experimental LLE results for the systems studied, and the binary interaction parameter values of the two models were optimized from the LLE correlation.

Measurement and Thermodynamic Modeling of Ternary (Liquid + Liquid) Equilibrium for Extraction of N,N-Dimethylacetamide from Aqueous Solution with Different Solvents

Liquid–liquid equilibrium (LLE) data for the water + N,N-dimethylacetamide + solvents (chloroform, methyl isobutyl carbinol, methyl isobutyl ketone, isopropyl acetate, or isopropyl ether) ternary systems were determined at 308.2 and 298.2 K and at 101.3 kPa. Distribution coefficients and separation factors were calculated to evaluate the effectiveness of extracting N,N-dimethylacetamide from aqueous solution. The Othmer–Tobias equation and the Hand equation were used to confirm the reliability of the experimental LLE data. The experimental data were correlated by thermodynamic nonrandom two-liquid and universal quasichemical models, and the binary interaction parameter values were obtained from the data correlation.

Measurement and thermodynamic modeling of ternary (liquid + liquid) equilibrium for extraction of o-cresol, m-cresol or p-cresol from aqueous solution with 2-pentanone

The (liquid+liquid) equilibrium (LLE) data are vital for the liquid extraction of cresols from aqueous solution with 2-pentanone as an extraction agent. Therefore, the ternary LLE data for {2-pentanone+o-cresol, m-cresol or p-cresol+water} were determined at T=(298.15and323.15)K and p=101.3kPa. And the reliability of the LLE data was ascertained by using the Othmer-Tobias and Hand equations. The distribution coefficients and separation factors were calculated to evaluate the effectiveness of extracting cresols from water. The thermodynamic NRTL and UNIQUAC models were used to correlate the experimental LLE data of the studied systems, and the binary interaction parameter values were obtained from the data correlation.

Modeling the methyldiethanolamine-piperazine scrubbing system for CO2 removal: Thermodynamic analysis

Aqueous solutions of methyldiethanolamine (MDEA) and piperazine (PZ) are commonly used solvent nowadays. In this work a thermodynamic analysis with the Electrolyte-NRTL model has been performed for systems composed of acidic gases and MDEA + PZ aqueous solution. ASPEN Plus® has been used for thermodynamic modeling. Values of binary interaction parameters for liquid phase activity coefficients have been estimated from regressions of experimental data. Moreover, the influence of the interactions between ion pairs and MDEA or PZ molecular species has been analyzed. The final aim is to obtain a reliable tool for design and simulation of absorption and stripping columns, fundamentals also in order to carry out energy saving studies.

Application of Peng-Robinson Equation of State for Calculating Solid-Vapor and Solid-Liquid Equilibrium of CH4-CO2 System

In this study, the performances of Peng-Robinson Equation of State combined with the classical mixing ruleswere evaluated to calculate solid-vapor equilibrium (SVE) and solid-liquid equilibrium (SLE) of CH4-CO2system. The evaluation was performed by comparing the calculated values with the literature data. In thecalculation of SVE, the new binary interaction parameter values (kij) of CH4-CO2 mixtures were proposed in thiswork based on the experimental data. The proposed kij obtained in this work might increase the accuracy ofPeng-Robinson Equation of State by reducing average absolute deviation in the temperatures between calculatedvalues and literature data from (2.18% to 0.26%), (0.88% to 0.70%) and (0.61% to 0.44%) at CO2 compositionof 1%, 1.91% and 2.93%, respectively. Significant improvement was found at CO2 composition of 1%. In thecalculation of SLE, new parameters were not proposed since the calculation using the existing (literature) kijgives good results with an average absolute deviation of 0.5%.

Influence of Gas Impurities on Thermodynamics of Amine Solutions. 1. Aromatics

New parameters for improving the Electrolyte-NRTL model have been regressed for acidic gas-MDEA aqueous solution systems containing aromatics. Values of binary interaction parameters for liquid phase activity coefficients are estimated from regressions of experimental data. Aspen Plus has been used for regressions and thermodynamic modeling. The focus of the work is to have better predictions of VLE of aromatic compounds in amine systems for acidic gases purification.

Influence of Gas Impurities on Thermodynamics of Amine Solutions. 2. Mercaptans

New parameters for improving the Electrolyte-NRTL model have been regressed for acidic gas-MDEA aqueous solution systems containing mercaptans. Values of binary interaction parameters for liquid phase activity coefficients are estimated from regressions of experimental data. Aspen Plus has been used for regressions and thermodynamic modeling. The focus of the work is to have better predictions of VLE of mercaptans in amine solutions for acidic gases purification.

Experimental study and phase equilibrium modeling of systems containing acid gas and glycol

In this work, we study phase equilibria of systems containing acid gases and glycols. The acid gases include carbonyl sulfide (COS), hydrogen sulfide (H2S), and carbon dioxide (CO2) while glycols include monoethylene glycol (MEG), diethylene glycol (DEG), and triethylene glycol (TEG). A brief literature survey on the solubility of the acid gases and hydrocarbons in glycols is presented. New experimental solubility data mainly for COS and some limited data for H2S in glycols from 276 to 333K and at elevated pressures are reported. Experimental measurements have been carried out using the “static-synthetic” method. The reliability and repeatability of the experimental work are demonstrated. The experimental solubility data for COS and glycols, from this work, and those for H2S and CO2 from the literature are modeled using the cubic-plus-association (CPA) equation of state (EoS). CPA parameters for pure components and binary systems are reported. Satisfactory correlations have been achieved using temperature-independent interaction parameters. Various modeling strategies and alternatives using CPA are tested and the results are critically evaluated. The variations and trends in the values of binary interaction parameters are discussed for the different systems studied.

A Parametric Study of the Choice of Binary Interaction Parameter and Equation of State for High Pressure Vapor-Liquid Equilibrium of Nitrogen – n-Dodecane Binary System

A parametric study of the effects of binary interaction parameter and real-gas equations of state on the high pressure vapor-liquid equilibrium of nitrogen-n-dodecane system was carried out. Different values of the binary interaction parameter reported in literature, including one which depends on temperature, were employed in different equations of state to predict the vapor-liquid equilibrium as a function of ambient pressure and temperature. The findings were compared against the available experimental values reported in literature. Constant values of binary interaction parameter, estimated based on temperature dependent values, are demonstrated to predict the experimentally observed vapor-liquid equilibrium values accurately. The Peng-Robinson equation of state and an average binary interaction parameter were demonstrated to predict the vapor-liquid equilibrium over a wide range of temperature and pressures for nitrogen-n-dodecane binary system.

CALCULATION OF VOLUMETERIC AND THERMODYNAMIC PROPERTIES FOR PURE HYDROCARBONS AND THEIR MIXTURES USING CUBIC EQUATIONS OF STATE

The objective of this study was to develop a complete package for prediction of volumetric and thermodynamic properties of pure hydrocarbons fluids and their mixtures in one and two phase regions. Two cubic equations of state that are Peng-Robinson and Soave-Redlich-Kwong were used with volatile and black oils respectively to calculate the desired properties in addition to bubble point and dew point pressures and temperatures. Different values of binary interaction parameter were used for each equation and effects of this parameter values on the prediction are examined. Also values of this parameter between the plus-fraction and other component have been evaluated for first time. In calculation of heat capacity, four different mixing rules have been proposed to evaluate the temperature derivatives in case of the mixtures. Wide comparisons with the literature experimental data were made which indicated that both equations of state predict accurately different properties and marked improvements are achieved by use binary interaction parameter other than zero. Also both equations predict bubble point pressure of a certain mixture approximately with same accuracies using the recommended values of binary interaction parameter. Among the proposed mixing rules, Kay’s one appeared the best one to determine temperature derivatives.

Phase equilibria of palm oil, palm kernel oil, and oleic acid + supercritical carbon dioxide and modeling using Peng–Robinson EOS

Vapor–liquid equilibria of the binary supercritical carbon dioxide (scCO 2) + oleic acid, scCO 2 + palm oil, and scCO 2 + palm kernel oil were measured at a wide range of temperatures from 333.2 to 373.2 K and pressures from 8.5 to 35 MPa in a circulation-type phase equilibrium apparatus. The samples from liquid and vapor phases were analyzed using UV–vis spectrometer and a liquid hold-up equipment. The phase equilibrium data were correlated with Peng–Robinson Equation of State (PR-EOS) using Wong–Sandler mixing rule and optimum values of binary interaction parameters were determined. The relative deviation between experimental data and predicted data was in the range of 6.9–8.7%, suggesting that the PR-EOS with Wong–Sandler mixing rule is capable of predicting the vapor–liquid equilibria of oleic acid + scCO 2, palm oil + scCO 2, and palm kernel oil + scCO 2.

From binary assessments to thermodynamic databases

Abstract The Calphad method is a very powerful method for dealing with phase equilibria and thermodynamic properties of multicomponent alloy systems. In fact, it is the only method that can do this. However, in order to do this it is necessary to construct multicomponent databases, and the requirements on thermodynamic evaluations, in particular of binary systems, are quite different compared to the case when they are only used as stand-alone evaluations. A number of these issues are discussed in this paper and in particular the influence of changes of the values of binary interaction parameters on the ternary systems Cr–Cu–Ni and Cr–Cu–Fe is investigated. In addition, the Cr–Mo–Ni system is chosen as an example of a system where pure extrapolations (thermodynamic) from its binary subsystems produce a completely incorrect phase diagram. As a conclusion it is found that a massive effort on experimental and computational (Calphad) investigations of ternary systems, supported by ab-initio calculations, is needed in order to make further progress in the field of alloy thermodynamics possible. The quality of a multicomponent database is strongly dependent on the fraction of ternary datasets included in the database.

An extension of the group contribution model for thermodynamic and transport properties of dilute gases

Earlier work of the group contribution method presented by Oh and Campbell [Oh and Campbell, 1997] for prediction of second virial coefficients and dilute gas transport properties has been repeated with a new set of normal alkane second virial coefficient data (methane, ethane, propane, and normal pentane critically compiled by Dymond and Smith [1980], normal hexane recommended by Dymond et al. [1986], and the recommendation for normal butane, heptane and octane updated by Tsonopoulos and Dymond [1997]). This method has been extended to molecular linear gases (carbon monoxide, oxygen and hydrogen) and to alkanes-gases mixtures. The functional group parameters were revised from the simultaneous regression of second virial coefficient and viscosity data. Group parameters values (CH0, CH1, CH2, CH3, CH4, double-bonded CH1 double-bonded CH2, N2, and CO2 groups) and 8 binary group interaction parameters (kN2-CH0,GC,kN2-CH1,GC, kN2-CH2,GC, kN2-CH3,GC,;kCO2-CH0,GC,kCO2-CH1,GC,;kCO2-CH2,GC, andK CO2-CH3,GC were revised. New group parameter values are given for gases beyond those presented earlier (CO, O2 and H2) and 19 group binary interaction parameter ValueS (kN2-CH1D, GC,kN2-CH2D,GC;kCO2-CH1D,GCkCO2-CH2D,GC;kCO-CH1,GC,kCO2-CH2,GC,kCO-CH3,GC, kCO-CH1D,GC,kCO-CH2D,GC,kO2-CH0,GC,kO2-CH1,GC,kO2-CH2,GC,kO2-CH2,GC,kO2-CH3,GC,kH2-CH0,GC,kH2-CH1,GC, kH2-CH2,GC,kH2-CH3,GC,kH2-CH1D,GC,kH2-CH2D,GC are presented for hydrocarbon mixtures with gases. Application of the model shows that second virial coefficient data can be represented with results comparable to those obtained by Oh and Campbell [1997] and by the corresponding states method of Tsonopoulos [ 1974]. The accuracy of the model in viscosity and diffusion coefficient predictions of dilute gases is comparable to the methods of Lucas [1980] and of the Fuller method [Fuller et al., 1966].

Phase‐equilibria calculation by group‐contribution perturbed‐hard‐sphere‐chain equation of state

AbstractA group‐contribution (GC) method was coupled with the perturbed‐hard‐sphere‐chain (PHSC) equation of state (EOS) to predict its characteristic parameters. This model can describe both equilibrium and volumetric properties of regular fluids and chain‐like molecules. The estimation of group contributions for the characteristic volume, surface area, and interaction energy was based only on vapor‐pressure and saturated liquid‐density values of low‐molecular‐weight compounds. It was successful in estimating the EOS parameters of high‐molecular‐weight compounds and chain‐like molecules. Some application results show its reliability but the method was not applied to all classes of compounds. Good estimation of polymer density was obtained by GC PHSC with only the knowledge of their molecular structure. For mixtures, the original model was retained; binary interaction parameters were regressed from vapor–liquid equilibria of binary systems. In most cases, only one binary interaction parameter is enough to describe binary systems in a wide range of temperatures. The same model is extended to the calculation of liquid–liquid equilibria of a system exhibiting both upper critical solution temperature (UCST) and lower critical solution temperature (LCST). In summary, the data required for calculating multicomponent phase equilibria are the molecular structure in term of functional groups and binary interaction parameter values.

Thermodynamic properties for model compounds of coal-liquids and their mixtures — measurements and calculations

Thermodynamic properties were calculated with various cubic equations of state for the model compounds of coal liquids and their mixtures. These properties included vapor pressure, molar volume, excess volume, excess enthalpy, and vapor–liquid equilibrium. Liquid densities were also measured in this work for bicyclohexyl and mixtures of quinoline+tetralin to complement the experimental data of importance to coal liquefaction processes. The Patel–Teja equation of state yielded better results for calculations of vapor pressures and liquid molar volumes. The values of binary interaction parameter k a12 as determined from different types of mixture properties were compared and examined for their reliability. The results showed that excess volumes were capable of serving as a reliable data basis for determination of the binary interaction parameter.