Quasi Chemical Research Articles

A Simple Highly Accurate Algebraic Model of Phase Transitions on Square, Hexagonal, and Triangular Flat Faces

A simple, highly accurate algebraic model is proposed for describing phase transitions on flat faces of square, hexagonal, and triangular structures. The model is derived using the cluster variational approach within the Ising model and expressed in an analytical form by choosing a basic closed-form cluster of the minimal size for each facet structure with nearest neighbors of z = 3 (triangular), 4 (square), and 6 (hexagonal). The new model provides three times more accurate equations for molecular distributions of particles in the Ising model than earlier analytical expressions. The model’s analytical equations allow direct calculations of molecular distributions. (Only iterative numerical means were used earlier to obtain results of the same accuracy.) The effect of refinements when considering correlation effects in the new model is compared to traditional mean-field and quasi-chemical (QCA) approximations when calculating isotherms and pair and cluster distribution functions. Analytical expressions are obtained for the critical temperature of a segregation-type phase transition.

High Temperature Stability of K-Pb Liquid Alloy

The study explores the thermo-physical properties of complex binary liquid potassium-lead alloy at temperature 848 K as a function of concentration by considering complex using different model equations. The Quasi Chemical approximation and the R-K equation are used to investigate features such as free energy, heat of mixing, chemical activity, and concentration fluctuation in the long wave limit at temperature of 848 K. However, at 900 K and 1000 K, these are exclusively examined using the R-K equation. The temperature dependent exponential interaction parameters proposed by Kaptay are taken into account in the RK equation. The study goes on to look at the alloy's viscosity and surface tension using the Budai-Benko-Kaptay model and the Kaptay's improved derivation of Butler equation. The mixing nature of the system is investigated in depth, with a focus on the interaction energy parameters between the alloy's surrounding atoms. The work investigates the fact that the liquid alloy has a moderately interacting as well as ordering character throughout a whole concentration range, and the computed theoretical thermodynamic facts are in reasonable agreement with the corresponding experimental data at 848 K. At greater temperatures, the alloy's tendency goes from ordering to segregating. The alloy's viscosity and surface tension decrease as the temperature rises.

Simulation separation of triglycerides from Calophyllum inophyllum oil with continuous countercurrent extraction process using Aspen HYSYS

The trends of industry 4.0 transform a process design to a cost-effective development with digital simulation. The objective of this study was to simulate the separation and purification of triglycerides from crude Calophyllum inophyllum oil with a continuous countercurrent extraction method using Aspen HYSYS V.11 to find the appropriate binary parameter coefficients and predict the optimal conditions. It is expected that the oil’s purity suitable with the edible oil standards (minimum 96% triglycerides and 0.3% free fatty acids). The variables used are the flow rate (n-hexane + oil) to methanol and the total mass ratio of solvent to oil. The C. inophyllum oil used contains 63.91% triglycerides, 15.76% free fatty acids, 12.25% diglycerides, and 4.66% monoglycerides. It was evaluated by applying NRTL (Non-Random Two Liquid) and UNIQUAC (Universal Quasi Chemical) fluid packages with binary interaction parameters of UNIFAC-VLE, UNIFAC-LLE, Immiscible, and Modified (fitting parameters). The most suitable fluid package and binary interaction parameter pairing was achieved by combining NRTL fluid package with Modified binary interaction. The highest purity of triglycerides was 92.86%alongside a simulation error of 0.01% while the free fatty acid was 2.17% and 0.91%, respectively, at solvents (hexane and methanol) to oil mass ratio of 6:1 with a hexane-oil to methanol flow rate ratio of 6:15 (LPH/LPH). By upscaling the n number in the extractor, this model can predict the best result of separation and purification of triglycerides with the highest purity of triglycerides and free fatty acids were 96.736% and 0,0001%, respectively. Thus, the edible oil standards can be met.

Vapor-Liquid Equilibrium (VLE) Curve for Furfural Purification from Oil Palm Empty Fruit Bunch Hydrolysate Solution with the UNIQUAC Model

Furfural is the main Oil Palm Empty Fruit Bunch (OPEFB) hydrolysis product. It can achieve high purity from hydrolysate distillation. Its equipment design can be done by utilizing vapor-liquid equilibrium (VLE) data to achieve high furfural purity. The purpose of this research is to develop a Vapor-Liquid Equilibrium (VLE) curve for furfural purification from Oil Palm Empty Bunch hydrolysate solution with the Universal Quasi Chemical (UNIQUAC) model. Distillation data is obtained from literature and examined on the Universal Quasi Chemical (UNIQUAC) model. Calculations for average deviation and R2 are also made to show the accuracy of the model quantitatively. The modeled VLE curve indicates that the UNIQUAC model and the literature distillation pattern are not ideal, and the UNIQUAC curve pattern closely follows the literature pattern. The average deviation and R2 values for this UNIQUAC model are 0.0954 and 0.297, respectively. These values are still acceptable and show that UNIQUAC can be used as useful model distillation data of furfural and water as the representatives of an OPEFB hydrolysate solution.

Experimental, theoretical and computational study of binary systems of alkanolamines and alkylamines with cyclohexanol at different temperatures

Density, ρ, speed of sound, u, and the difference in the temperature before and after the mixing process , ΔT, were measured for binary mixtures containing of cyclohexanol (CYC) + diethanolamine (DEA) or triethanolamine (TEA) or butylamine (BUT) or hexylamine (HEX) at (303.15–318.15) K except ΔT at 303.15 K. The excess molar volume, VmE, excess partial molar volume, Vm,iE, excess thermal expansion coefficient, αE, isothermal coefficient of excess molar enthalpy,(∂HmE∂P)T,x, deviation in isentropic compressibility,Δκs, excess molar enthalpy,HmE, and excess partial molar enthalpy, Hm,iE, were also calculated. The calculated data were satisfactorily correlated by Redlich – Kister equation. Some empirical models such as (Prigogine–Flory–Paterson) PFP, Wilson, (Non-Random Two Liquid) NRTL and (universal quasi chemical) UNIQUAC. Computational methods were performed using density function theory (DFT) and molecular dynamics (MD) simulation and were used to discuss and compare intramolecular and intermolecular interactions. An acceptable agreement was found between empirical and theoretical data.

Liquid metals: Thermophysical properties of alloys from the Ga-Sn-Zn system

Liquid metals are a group of functional materials of growing importance in the recent years. In this work, the density, viscosity and surface tension of liquid Ga-Sn-Zn alloys for compositions with the Sn/Zn ratio of 3/1, 1/1 and 1/3 with Ga additions have been determined by the discharge crucible method. An attempt was done to describe the abovementioned properties as a function of temperature and composition. The new thermophysical property data were compared to the values predicted by models. The Moelwyn-Hughes, Kozlov-Romanov-Petrov, Sato, Schick and Gasior models for viscosity, and for density, the Brillo and Egry and ideal solution models were applied. The surface tension of binary liquid alloys was analysed in the framework of the Butler and Quasi Chemical Approximation for regular solution (QCA), while to describe the surface tension of ternary melts, the models of Butler, Toop, Kohler and Muggianu were used.

Determination and modelling of density, viscosity and solubility of (R)-(-)-phenylephrine hydrochloride in methanol + ethyl acetate at (278.15–323.15) K and 0.1 MPa

For further optimizing the pipeline design of continuous crystallizer, in this research work, density, viscosity and solid-liquid equilibria (SLE) solubility of (R)-(-)-phenylephrine hydrochloride (R-PEC) in binary solvent of “methanol (MtOH) + ethyl acetate (EtAC)” were investigated at temperature T = (278.15–323.15) K under pressure p = 0.1 MPa. The results showed that experimental density and viscosity values were negatively related with temperature while the SLE solubility data had positive correlation with the experimental temperature. Moreover, density and viscosity profiles increased with the incremental molarity of R-PEC, similarly, solubility of R-PEC raised along with the mass fraction of MtOH in binary solvents. Hansen solubility parameter (HSP) was applied to investigate the solubility behavior of R-PEC in MtOH+EtAC, four selected solubility parameters could give a logical explanation on R-PEC solubility. By using Mathcad software (Version: 15), the Vogel-Tammann-Fulcher (VTF) equation was employed for the description of density as well as viscosity values. Values of average relative deviation (ARD), multi-correlation coefficient (R2) and root-mean square deviation (RMSD) between experimental data and predicted data showed that VTF equation could provide satisfactory correlations with the experimental data. Besides, solubility values of R-PEHC in selected binary solvent were correlated with three activity coefficient models including Wilson, NRTL (Non-Random Two Liquids) and UNIQUAC (Universal Quasi–Chemical) model by using Mathcad software, the UNIQUAC model were more suitable for correlation with experimental solubility than others in terms of ARD and RMSD. Furthermore, based on the experimental solubility results and regression parameters of UNIQUAC model, thermodynamic properties of mixing and dissolution process were discussed in this work, the results showed that the both processes of R-PEHC in MtOH+EtAC were always spontaneous and entropy driven, the mixing process and part of dissolution process (R-PEHC in MtOH + EtAC at T ≤ 303.15 K) were exothermic. Experimental densities, viscosities, solubility as well as selected models would be very helpful for optimizing the pipeline design (including material selection, size calculation and so on) of continuous crystallizer.

Surface Properties of Liquid Al-Ni Alloys: Experiments Vs Theory

The present study is an overview of the surface properties of liquid Al-Ni alloys, which are of great importance for the design and development of new Al-Ni and Ni-based industrial alloys, widely used as functional and structural materials. The solidification and thus, the microstructural evolution are directly dependent on the interface/surface properties of metallic melts. Therefore, numerical simulation of microstructure evolution requires reliable property data as input to such models. Taking into account the experimental difficulties related to a high reactivity of liquid Al-Ni alloys and the effects of impurities on their surface properties, the surface tension over the whole concentration range has been determined in the frameworks of three international research projects. Namely, the surface tension measurements have been carried out by both traditional container-based and as an alternative, containerless methods within the ESA-MAP ThermoProp and ESA-MAP Thermolab Projects and also under the EU FP6-IMPRESS Project. The obtained datasets were analysed and subsequently compared with the model predicted values as well as with the literature data. A strong exothermic mixing characterises the Al-Ni system and the presence of a few intermetallic compounds in the solid state leads to the formation of short range ordered elements or complexes in the liquid phase, at least near the melting temperature, which significantly affects the surface properties of alloy melts. Aiming to estimate the effects of short range ordering on these properties, the Compound Formation Model (CFM) and the Quasi Chemical Approximation (QCA) for regular solution were applied.

Deacidification of Amazonian Pracaxi (Pentaclethra macroloba) and Patawa (Oenocarpus bataua) oils: experimental and modeling of liquid–liquid extraction using alcoholic solvents

This paper presents a study about the deacidification of typical Amazonian oils, namely, patawa and pracaxi oils. The liquid–liquid extractions were carried out using three alcoholic solvents: anhydrous ethanol, azeotropic ethanol, and azeotropic isopropanol at 298.15 K and atmospheric pressure. Liquid–liquid equilibrium data for the oils + oleic acid + solvents systems were determined. The azeotropic ethanol was found to be the best extractant for removing free fatty acids (FFAs) since its use provided the highest selectivity values (from 62.98 to more 1.53 × 103), reasonable distribution coefficients (from 1.06 to 1.47), and reduced loss of neutral oil (oil concentrations lower than 1.49 wt% in the alcoholic phases). Moreover, the obtained experimental data were correlated using the nonrandom two-liquid (NRTL) and universal quasi chemical (UNIQUAC) activity coefficient models. The deviations between calculated and experimental values ranged from 0.39 to 1.22 and from 0.28 to 1.10 for the various studied systems using the UNIQUAC and the NRTL models, respectively. Such results indicate the positive perspective of using the liquid–liquid extraction technique for patawa and pracaxi oils refining and the feasibility of using ethanol as an FFA extractant.

Study on Particle Swarm Optimization Variant and Simulated Annealing in Vapor Liquid Equilibrium Calculation

Phase equilibrium calculation plays a major rule in optimization of separation process in chemical processing. Phase equilibrium calculation is still very challenging due to highly nonlinear and non-convex of mathematical models. Recently, stochastic optimization method has been widely used to solve those problems. One of the promising stochastic methods is Particle Swarm Optimization (PSO) due to its simplicity and robustness. This study presents the capability of particle swarm optimization for correlating isothermal vapor liquid equilibrium data of water with methanol and ethanol system by optimizing Wilson, Non-Random Two Liquids (NRTL), and Universal Quasi Chemical (UNIQUAC) activity coefficient model and also presents the comparison with bare-bones PSO (BBPSO) and simulated annealing (SA). Those three optimization methods were successfully tested and validated to model vapor liquid equilibrium calculation and were successfully applied to correlate vapor liquid equilibrium data for those types of systems with deviation less than 2%. In addition, BBPSO shows a consistency result and faster convergence among those three optimization methods. Keywords: Phase equilibrium, stochastic method, particle swarm optimization, simulated annealing and activity coefficient model

Experimental and Thermodynamic Modeling of Quaternary Aqueous Two-Phase System of Poly Ethylene Glycol, Sodium Tartrate, Water and Penicillin G

In present study, the liquid–liquid equilibrium of the quaternary system of polyethylene glycol (PEG) (with molar masses of 1000, 2000, 6000, and 8000 g·mol−1), sodium tartrate salt, Penicillin G and water at 298 K were investigated. The partitioning of Penicillin G between two aqueous phases was also reported. The extended non random two liquid (NRTL) and extended Universal Quasi Chemical (UNIQUAC) models were used to correlate the experimental equilibrium data. The parameters of these activity coefficient models were optimized for the investigated systems. The results show that the polymer molar mass has a dominant effect on the partition coefficient of Penicillin G. Also, results of both thermodynamic models were very satisfactory and satisfactory predicted the equilibrium concentrations of the components in ATPS. Comparison of the absolute average deviation of the two models shows that the extended UNIQUAC model was superior to the extended NRTL model for correlation and interpolation of phase equilibrium data.

Solubility and mixing thermodynamic properties of levamisole hydrochloride in twelve pure solvents at various temperatures

The solubility of solid compounds and active pharmaceutical ingredient in different solvents is important for its crystallization and purification industry. In this work, by using a laser dynamic method, the solubility of levamisole hydrochloride in methanol (MT), ethanol (ET), isopropanol (IPA), n-propanol (NPA), n-butanol (NBA), 2-butanol (SBA), isobutanol (IBA), n-pentanol (NPT), 3-methyl-1-butanol (IAA) and n-hexanol (NHA) from (283.15 to 323.15) K, dimethyl sulfoxide (DMSO) from (293.15 to 333.15) K and water from (283.15 to 308.15) K were measured under atmospheric pressure. The measured results showed that the experimental solubility of levamisole hydrochloride increased non-linearly with the temperature in the studied pure solvents. The measured solubility data were all correlated by the Yaws model equation, non-random two liquid (NRTL) model equation, universal quasi chemical (UNIQUAC) model equation, Wilson model equation and λh equation. Besides, the logarithm of activity coefficient of levamisole hydrochloride (lnγ1) were calculated with the NRTL model, Wilson model and UNIQUAC model. The maximum relative average deviation (ARD) was 0.2008, the maximum root-mean-square deviation (RMSD) was 0.0089. Basically speaking, the measured solubility data in this study can be well correlated with the five thermodynamic models. Based on the solubility data and Wilson model, the mixing entropy, mixing enthalpy and mixing Gibbs energy were evaluated. The logarithm of the solute activity coefficients lnγ1in the studied saturated solutions were calculated, The positive values of lnγ1 means that the repulsive interactions exist between levamisole hydrochloride and the corresponding solvents (NBA, NPA, NHA, IPA, IBA, SBA and IAA), and the solutions system positively deviate from Raoult’s law; The negative values of lnγ1 means that the attractive interactions exist between levamisole hydrochloride and the corresponding solvents (MT, ET, NPT, DMSO and water), and the solutions system minus deviate from Raoult’s law. This work can give fundamental data for the crystallization and purification of levamisole hydrochloride.

Lattice fluid with attractive interaction between nearest neighbors and repulsive interaction between next-next-nearest neighbors on simple cubic lattice

The lattice system with competing interactions (attractive between nearest neighbors and repulsive between next-next-nearest neighbors) on a simple cubic lattice is studied. It is shown that the competing interactions lead to the order-disorder phase transitions. The geometric order parameter for localizing the second-order phase transition points is introduced. With its help the critical value of the interaction parameter was established, and the phase diagram of the system was constructed. An analytical quasi-chemical (QChA) approximation for evaluation of the equilibrium parameters of the system is proposed. The chemical potential, the thermodynamic factor, and the correlation functions are determined both within the framework of the developed approximate approach and as a result of the Monte Carlo simulation of the lattice system. The obtained dependence of the thermodynamic factor of the system on concentration indicates a strong suppression of fluctuations, characteristic for an ordered state. In turn, the complex nature of the concentration dependence of the correlation functions reflecting the structural features of the system demonstrates the important contribution of competing interactions. The proposed analytical approach allows one to correctly describe the qualitative features of the structural properties of systems with competing interactions and can be used to quantify the thermodynamic characteristics of these systems.

Liquid–Liquid Equilibrium for Systems Containing Epoxidized Oils, Formic Acid, and Water: Experimental and Modeling

AbstractEpoxidized oils are eco‐friendly plasticizers, which are industrially produced through the epoxidation reaction in a formic acid‐hydrogen peroxide autocatalyzed system. The fundamental knowledge to describe the phase equilibrium of systems after epoxidation reaction is lacking, which is crucial for the design of the purification facilities. This work reported experimental data for the liquid–liquid equilibrium of three systems, i.e., epoxidized fatty acid methyl esters + formic acid + water, epoxidized fatty acid 2‐ethylhexyl esters + formic acid + water, and epoxidized soybean oil + formic acid + water, in the temperature range (303.15–348.15) K under atmospheric pressure. The results indicated that the liquid–liquid equilibrium constant of formic acid in the systems followed the order of epoxidized fatty acid 2‐ethylhexyl esters > epoxidized fatty acid methyl esters > epoxidized soybean oil. Moreover, the obtained experimental data were correlated using nonrandom two liquid (NRTL) and universal quasi chemical (UNIQUAC) models. The maximum root mean square deviation (RMSD) values as low as 0.0052 and 0.0263 were estimated using the NRTL and UNIQUAC model, respectively. The NRTL model is more suitable than the UNIQUAC model to describe the liquid–liquid equilibrium behavior of these ternary systems.

Measurements and correlation of liquid–liquid equilibrium data for the ternary (methyl tert-butyl ketone + o, m, p-benzenediol + water) system at (333.2, 343.2 and 353.2) K

In this work, liquid–liquid equilibria (LLE) data for the ternary system methyl tert-butyl ketone (MTBK) + o, m, p-benzenediol + water were investigated at 333.2 K, 343.2 K and 353.2 K under 101.3 kPa. The performance of MTBK to extract o, m, p-benzenediol from wastewaters was estimated by partition coefficients and separation factors. The Hand and Bachman equations were both applied to check the reliability of the experimental LLE data. Furthermore, the Non-Random Two-Liquid (NRTL) and Universal Quasi Chemical (UNIQUAC) models were applied to correlate the measured LLE data. The results showed a good agreement with the determined ternary LLE data with the root-mean-square error (RMSE) values below 0.71%. MTBK was proved to be a promising extracting agent in extracting benzenediols from effluents.

Surface and transport properties of liquid Ag–Sn alloys and a case study of Ag–Sn eutectic solder

This review represents the state of the art in the thermophysical properties of liquid Ag–Sn alloys highlighting the surface and wetting properties of Ag–Sn eutectic solder. It includes an atomistic approach developed within the framework of statistical mechanical theory in conjunction with a Quasi Lattice Theory that, through a rigorous mathematical formalism, provides exact relationships between the properties in terms of classical thermodynamics. The model predicted property values are substantiated by available experimental data. Based on the phase diagram evidence about the existence of e-Ag3Sn intermetallic compound, the surface (surface tension and surface composition), transport (viscosity and diffusivity) properties and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) have been studied using the Compound Formation Model in a weak interaction approximation and Quasi Chemical Approximation for regular solutions. A case study of Ag–Sn eutectic alloy is presented. Taking into account its importance for design and development of lead free solder alternatives, the literature data on the wettability and the phases formed at the interface between Ag–Sn eutectic alloy and different substrates (Cu, Ni, Au, Pd) have also been analysed.

Thermodynamic modeling of the K-KCl and Mg-MgCl2 binary systems using the CALPHAD method

The Calculation of Phase Diagrams (CALPHAD) method uses models that reproduce and predict phase equilibria and thermochemical behavior. To date, the CALPHAD approach has been applied to the KCl-MgCl2 psuedobinary only. The two-sublattice modified quasi chemical (MQM) model, already developed for the KCl-MgCl2 melt and used extensively within the CALPHAD community to represent molten salts, is extended in this work to include excess K and Mg. Phase relations calculated using the MQM is compared to experimentally observed behavior for the K-KCl binary system. Gaps in the experimental data are identified and recommendations are given for better understanding the thermochemistry and phase equilibria.

The Maxwell–Stefan description of mixture permeation across nanoporous graphene membranes

There is increasing research interest on the use of two-dimensional (2D) nanoporous materials, such as graphenes and graphene oxides, in a variety of membrane separation applications. The membrane permeation selectivitites are governed by a variety of factors that include surface diffusion as an important constituent. The primary objective of this article is to present a Maxwell–Stefan (M–S) formulation for surface diffusion of binary (1, 2) mixtures on 2D nanoporous graphene surfaces. In the developed formulation, adsorbate–adsorbate interactions, either attractive or repulsive, are described by the quasi-chemical (QC) mean field approximation of Guggenheim. Such interactions have a direct influence on the occupancy dependencies of the M–S diffusivities, Ð1 and Ð2, that quantify molecule-surface “friction”. An essential feature of the M–S formulation is the inclusion of exchange coefficients, Ð12, that quantify correlation, or slowing-down effects for surface diffusion; the tardier-more-strongly-adsorbed species usually “slows down” the more-mobile-less-strongly-adsorbed species. Kinetic Monte Carlo (KMC) simulations on 2D square lattice of adsorption sites are used to quantify the the loading dependence of the M–S diffusivities, and also correlation effects. The usefulness of the developed model, combining QC and M–S approaches, is illustrated for CO2/CH4, CO2/H2, CO2/N2, and CH4/H2, mixture separations. For all four mixtures, the neglect of correlation effects leads to a severe underestimation of the membrane permeation selectivities that favor the more strongly adsorbed species.

Phase Equilibrium on Extraction Methylphenols from Aqueous Solution with 3,3-Dimethyl-2-butanone at 333.2 K and 353.2 K

The phenols recovery process is a significant part of treating coal chemical wastewater with highly concentrated phenols and ammonia. Solvent extraction is an important unit for phenol recovery section. The accurate measurement of liquid–liquid equilibrium (LLE) data is essential for realizing partitioning. In this paper, the LLE data for the ternary system water + 2-, 3-, 4-methylphenol +3,3-dimethyl-2-butanone (also known as methyl tert-butyl ketone, MTBK) were studied at the temperatures of 333.2 K and 353.2 K under 101.3 kPa. The extraction performance of MTBK was estimated by partition coefficients and separation factors. The extraction efficiencies of MTBK were compared with those of MIBK, mesityl oxide, and those results of MTBK at five different temperatures from 298.2 K to 353.2 K were also contrasted with each other. In addition, the nonrandom two-liquid (NRTL) and universal quasi chemical (UNIQUAC) models were applied to fit the measured LLE data. The results indicate that the calculated data b...

Liquid–Liquid Equilibrium of Ternary Systems of Methyl Isobutyl Ketone + o-Cresol + Water at 298.2, 313.2 and 323.2 K

Liquid–liquid equilibrium (LLE) data for the methyl isobutyl ketone + o-cresol + water ternary system have been experimentally measured from 298.2 to 323.2 K below 101 kPa. The measured LLE data were verified to be highly consistent through the Othmer–Tobias and Hand equations. The extraction efficiency of methyl isobutyl ketone for o-cresol was assessed by the distribution coefficient and separation factor. The experimental results correlated well with two excess Gibbs energy models: non-random two-liquid and universal quasi chemical, which also yielded binary interaction parameter.