Vapor-liquid Equilibrium Data Research Articles

Clean and efficient recovery of In–Sn and In–Sn–Bi lead-free brazing materials by vacuum volatilization and thermodynamic modeling

In this study, a novel method was proposed for the clean and efficient recovery of high-value-added In–Sn and In–Sn–Bi alloys. Vacuum volatilization of the In–Sn binary alloy was conducted in a temperature range of 1373–1573 K with a system pressure of 5 Pa. The results showed that In and Sn were effectively separated. The Sn content in the residue was 99.9908%, and the In content in the volatile fraction reached 99.66%. Vacuum volatilization of the In–Sn–Bi ternary alloy was conducted out at 1073–1373 K and 5 Pa. The results showed that Bi could be separated from In and Sn, the Bi content in the residue decreased from 32.5% to 3.88%, and the Bi content in the volatile fraction reached 95.67%. The residual In–Sn alloy could be effectively separated by vacuum volatilization. The MIVM, M-MIVM, Wilson equation and NRTL were used to calculate and analyze the activity and activity coefficients of In–Sn, In–Bi, Sn–Bi and In–Sn–Bi alloy elements, respectively, and the results showed that M-MIVM had the highest prediction accuracy. The vapor-liquid equilibrium (VLE) data of the In–Sn, In–Bi, Sn–Bi, and In–Sn–Bi alloys were predicted, and the corresponding VLE phase diagrams were plotted based on the M-MIVM and VLE theory. The predicted VLE values were in good agreement with the corresponding experimental data determined in this study, indicating that the M-MIVM was reliable for indium-based alloys. The results of this work provided reliable experimental data and a thermodynamic model for the VLE study of In-based alloys, opening a new technique for the clean and efficient recycling of binary and multicomponent In-based alloys.

Effective Absorption of Dichloromethane Using Carboxyl-Functionalized Ionic Liquids.

Dichloromethane (DCM) is recognized as a very harmful air pollutant because of its strong volatility and difficulty to degrade. Ionic liquids (ILs) are considered as potential solvents for absorbing DCM, while it is still a challenge to develop ILs with high absorption performances. In this study, four carboxyl-functionalized ILs-trioctylmethylammonium acetate [N1888][Ac], trioctylmethylammonium formate [N1888][FA], trioctylmethylammonium glycinate [N1888][Gly], and trihexyl(tetradecyl)phosphonium glycinate [P66614][Gly]-were synthesized for DCM capture. The absorption capacity follows the order of [P66614][Gly] > [N1888][Gly] > [N1888][FA] > [N1888][Ac], and [P66614][Gly] showed the best absorption capacity, 130 mg DCM/g IL at 313.15 K and a DCM concentration of 6.1%, which was two times higher than the reported ILs [Beim][EtSO4] and [Emim][Ac]. Moreover, the vapor-liquid equilibrium (VLE) of the DCM + IL binary system was experimentally measured. The NRTL (non-random two-liquid) model was developed to predict the VLE data, and a relative root mean square deviation (rRMSD) of 0.8467 was obtained. The absorption mechanism was explored via FT-IR spectra, 1H-NMR, and quantum chemistry calculations. It showed a nonpolar affinity between the cation and the DCM, while the interaction between the anion and the DCM was a hydrogen bond. Based on the results of the study of the interaction energy, it was found that the hydrogen bond between the anion and the DCM had the greatest influence on the absorption process.

Correlation and Prediction of Isobaric Vapor–Liquid Equilibria of Binary and Ternary Systems Containing Oxygenated Biofuel Compounds (Butan-2-one + 2-Methylpropan-1-ol + Cyclopentanone) at Atmospheric Pressure

Process modeling and feasibility studies for biofuel production require accurate phase equilibria data. Binary mixtures of common biofuel compounds butan-2-one + 2-methylpropan-1-ol, butan-2-one + cyclopentanone, 2-methylpropan-1-ol + cyclopentanone, and a ternary system of all three components were studied to obtain vapor–liquid equilibrium data at atmospheric pressure. The experimental data were validated and verified thermodynamically by employing the modified McDermott–Ellis, Van Ness, and Herington methods. The binary vapor–liquid equilibrium (VLE) data were successfully correlated with the Wilson, NRTL, and UNIQUAC activity coefficient models and predicted with the PSRK model. Further, the PSRK model and NRTL with the obtained binary interaction parameter (BIP) model were applied to forecast VLE data for the ternary system of butan-2-one + 2-methylpropan-1-ol + cyclopentanone. Both PSRK and NRTL models showed good accuracy in predicting the equilibrium temperature. At the same time, the PSRK model outperformed the NRTL model in predicting the composition of the vapor phase. The PSRK model was quite accurate for predicting the VLE of these biofuel components, even without any experimental data.

Isothermal (Vapour + Liquid) Equilibrium Measurements and Correlation of the Binary Mixture {3,3,3-Trifluoropropene (HFO-1243zf) + 2,3,3,3-tetrafluoropropene (HFO-1234yf)} at Temperatures from 283.15 K to 323.15 K

The many constrains introduced by the F-gas Regulation and the Kigali Amendment to the Montreal Protocol have resulted in an intense search for alternatives to fluorinated greenhouses gases for air conditioning and refrigeration purposes (Mota-Babiloni A, Makhnatch P, in Int J Refrig 127:101–110, 2021). With respect to the urge of new low-GWP and low-ODP refrigerants, blends composed of hydrofluoroolefins (HFO) are considered promising possible substitutes to hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) for HVAC&R applications (Sovacool et al., in Renew Sustain Energy Rev 141:110759), but thermophysical properties data for these blends are still scarce (Bell et al., in: J Chem Eng Data, 2021). In the present study, the vapor–liquid equilibrium (VLE) for the binary system (HFO-1243zf + HFO-1234yf), for which just one set of data on the VLE is available to date in literature, has been experimentally studied by means of a vapor recirculation apparatus. The measurements have been performed at isothermal conditions in the range of temperatures between 283.15 K and 323.15 K, while the composition of both the phases in equilibrium has been measured by gas-chromatographic analysis. The experimental VLE data have been correlated by two different equations of state (EoS): the Peng-Robinson (PR) EoS combined with Mathias–Copeman (MC) alpha function and van der Waals (vdW) mixing rules, and the Helmoltz EoS with dedicated binary interaction parameters. Correlated results showed a good agreement with the experimental data for the binary system.

Density, Excess Molar Volume and Vapor–Liquid Equilibrium Measurements at 101.3 kPa for Binary Mixtures Containing Ethyl Acetate and a Branched Alkane: Experimental Data and Modeling

Vapor–liquid equilibrium (VLE) and density data for binary systems of branched alkanes + ethyl acetate are scarce in the literature. In this study, the binary mixtures 3-methylpentane + ethyl acetate and 2,3-dimethylbutane + ethyl acetate were investigated. Density measurements at atmospheric pressure were performed using a vibrating tube density meter at 293.15, 298.15 and 303.15 K. Large and positive excess molar volumes were calculated and correlated using a Redlich–Kister-type equation. Isobaric VLE data at 101.3 kPa were obtained using a Gillespie-type recirculation ebulliometer. Equilibrium compositions were determined indirectly from density measurements. The experimental data were checked for consistency by means of the Fredenslund test and the Wisniak (L-W) test and were then successfully correlated using the NRTL model. The newly studied binary systems display high deviations from ideality and minimum boiling azeotropes, the coordinates of which are reported in this work.

Conceptual design and process construction of [formula omitted]-propyl propionate production by reactive distillation

The purpose of this work is to perform the conceptual design and process construction of n-propyl propionate synthesis by reactive distillation. Firstly, the reaction kinetic and thermodynamic models were summarized. The isobaric vapor-liquid equilibrium data of the binary systems 1-propanol (1) + n-propyl propionate (2) and propionic acid (1) + n-propyl propionate (2) were measured. The UNIQUAC model was used to describe the thermodynamic behavior of this system. Secondly, non-reactive residue curve maps and reactive residue curve maps analyses were used for conceptual design to obtain the preliminary configuration and operating conditions of the reactive distillation column. Finally, the sensitivity analysis was used to evaluate the preliminary process configuration and identify key operational variables.

Measurement of vapor-liquid equilibrium for the binary system propene (R1270) + trans-1,3,3,3‑tetrafluoropropene (R1234ze(E)) at temperatures from 288.18 K to 318.18 K

The search for alternative refrigerants that are environmentally friendly and highly efficient has become one of the most urgent and important issues facing the refrigeration industry. R1270 has excellent thermodynamic properties, but its high flammability limits its range of applications. R1234ze(E) is an environmentally friendly refrigerant with negligible flammability though it has the drawback of poor heat transfer performance. R1270 can be blended with R1234ze(E) as a new mixture refrigerant. vapor–liquid equilibrium (VLE) is the basic physical property of mixtures. The vapor–liquid equilibrium data have been measured for the binary system R1270/ R1234ze(E) based on the liquid-phase cycling method at four temperatures (288.15 K, 298.15 K, 308.15 K, 318.15 K). All the experimental data were regressed by the Peng-Robinson (PR) equation of state (EoS) with the Huron–Vidal (HV) mixing rule involving the non-random two-liquid (NTRL) activity coefficient model, and the PR EoS relating to the van der Waals (vdWs) mixing rule. The results show that the predicted values by the two models are in good agreement with the experimental data, and the prediction accuracy of the PR + HV + NTRL model was higher than that of the PR + vdWs model. In addition, azeotropic behaviors of the binary mixture have been found in the measured temperature range.

Measurement and Correlation of Isobaric Vapor–Liquid Equilibrium Data for n-Hexane, Methylcyclopentane and N,N-Dimethylamide Systems at 101.3 kPa

Measurement and Correlation of Isobaric Vapor–Liquid Equilibrium Data for n-Hexane, Methylcyclopentane and N,N-Dimethylamide Systems at 101.3 kPa

Vapor Liquid Equilibrium of Aqueous Diethanolamine Solution for Carbon Dioxide Capture Processes

Objectives : Acid gases such as carbon dioxide (CO<sub>2</sub>) and hydrogen sulfide (H<sub>2</sub>S) that cause global warming are mainly generated in chemical processes. As a technology for reducing acid gas, the post-combustion capture process is representative. Aqueous alkanolamine solution, which is mainly used in the carbon dioxide absorption process, is used as the most representative chemical absorbent. Thermodynamic data of vapor-liquid equilibrium are important for the economics of process design and operation. In this study, vapor-liquid equilibrium data of water + DEA are measured so that DEA, a secondary amine, can be used in the carbon dioxide absorption process, so that it can be used for designing a new carbon dioxide absorption process.Methods : Vapor-liquid equilibrium data of a mixture of water + DEA (diethanolamine) were measured under isothermal conditions of 393.15 K using HSGC (Headspace Gas Chromatography).Results and Discussion : The measured vapor-liquid equilibrium data were correlated using NRTL, an activity coefficient model. In addition, as additional thermodynamic data of the absorbent mixture, the density of the DEA aqueous mixture was measured at a temperature of 303.15 K to 333.15 K using a density meter (Anton Paar DMA4500). The measured density data of the mixture was converted into excess volume, and the excess volume data was correlated using the Redilchi-Kister-Muggianu equation. Using the measured water+DEA vapor-liquid equilibrium data, it is expected to reducing the design cost and operating cost of the carbon dioxide absorption processes.

Measurement and Correlation of Isothermal Vapor–Liquid Equilibrium Data for (−)-α-Pinene + (−)-β-Pinene + Water + Phenoxyacetic Acid

Isothermal vapor–liquid equilibrium data of the binary system (−)-α-pinene + (−)-β-pinene and the quaternary system (−)-α-pinene + (−)-β-pinene + water + phenoxyacetic acid were measured at 313.2, 323.2, and 333.2 K using headspace gas chromatography. The experimental data showed that the addition of phenoxyacetic acid and water promoted the separation of (−)-α-pinene and (−)-β-pinene. The experimental data were correlated using the UNIQUAC and NRTL models. The two models showed good correlation for the binary system, whereas the UNIQUAC model gave more accuracy for the quaternary system. Moreover, the COSMO-RS model can be an efficacious method for predicting VLE data of the determined binary and quaternary systems. In addition, the optimal spatial configuration and binding energy between the molecules were obtained by DFT, and the effects on (−)-α-pinene and (−)-β-pinene with the addition of phenoxyacetic acid and water were discussed on the molecular scale.

Determination and Correlation of Vapor–Liquid Equilibria for the Nitric Acid + Water, Nitric Acid + Water + Phosphoric Acid, and Nitric Acid + Water + Phosphoric Acid + Sulfuric Acid System

The wet-process production of phosphoric acid by the nitric acid method is considered as a promising technology with great development prospects due to no production of the byproduct phosphogypsum. However, the traditional nitro-phosphate fertilizer producing process cannot separate nitrogen and phosphorus thoroughly, which limits its applications. The key to solving this problem is to remove nitric acid from the crude phosphoric acid product obtained in the nitric acid wet process by evaporation. Therefore, it is important to measure the vapor–liquid equilibrium (VLE) data of the nitric acid + water + phosphoric acid + sulfuric acid quaternary system under different pressures and concentrations. In this study, the VLE data of the following systems were measured at 10, 20, 40, 60, 80, and 97.4 kPa by the quasi-static ebulliometric method: (1) nitric acid + water; (2) nitric acid + water + phosphoric acid; and (3) nitric acid + water + phosphoric acid + sulfuric acid. The electrolyte non-random two-liquid parameters for the following pairs were correlated with the VLE data by using Aspen Plus as a tool: HNO3-H2O, H3PO4-H2O, HNO3-H3PO4, HNO3-H2SO4, H3PO4-H2SO4, H+[H2PO4]−-H+[NO3]−, H+[NO3]−-H+[HSO4]−, and H+[H2PO4]−-H+[HSO4]−. The obtained VLE data and interaction parameters can provide the basis for the nitric acid method of mother liquor denitrification in the subsequent industry.

Quantitative Analysis of Silicon Tetrachloride, Carbon Disulfide, and Dichloroethane Concentration by Raman Spectroscopy

Quantitative analysis of silicon tetrachloride, carbon disulfide, and dichloroethane concentrations to obtain vapor-liquid equilibrium data of the SiCl4-CS2 and SiCl4-C2H4Cl2 binary systems was established by Raman spectroscopy. The cheap glass sampling pipe was used as a carrier for Raman spectroscopy measurements. The Raman peak height of the internal standard was used to remove interference factors such as sampling pipe diameter, temperature, laser power, and other effects from the instrument. The peak height ratio between the Raman characteristic peak of the analyte and that of the internal standard was proportional to the analyte concentration. During the measuring process of vapor-liquid equilibrium data for the SiCl4-C2H4Cl2 binary system, the linear equation of y = 0.0068 + 0.75x with R2 of 0.9939 was used for the determination of SiCl4 concentration at the 422 cm−1 band. The linear equation of y = 0.0019 + 0.2266x with R2 of 0.9966 was used for the determination of C2H4Cl2 concentration at the 754 cm−1 band. For the SiCl4-CS2 binary system, the linear equation of y = 0.0494 + 4.7535x with R2 of 0.9962 was used for the determination of SiCl4 concentration at the 422 cm−1 band. The linear equation of y = 0.8139 + 8.7366x with R2 of 0.9973 was used for the determination of CS2 concentration at the 654 cm−1 band. The concentration of standard samples calculated by these standard curves was compared with the actual value to verify the accuracy of this method. The reproducibility is good when determining silicon tetrachloride and dichloroethane concentrations for the SiCl4-C2H4Cl2 binary system, with RSEP values of 2.81% and 2.17%, respectively. Meanwhile, the RSEP values are 3.55% and 4.16%, respectively, when determining silicon tetrachloride and carbon disulfide concentrations for the SiCl4-CS2 binary system.

Isobaric Vapor–Liquid Equilibrium of the Binary Mixtures Toluene + Styrene and Styrene + α-Methylstyrene

Isobaric vapor–liquid equilibria of the binary mixtures toluene + styrene at 30 and 40 kPa and styrene + α-methylstyrene at 20 and 25 kPa were measured applying a recirculation still. The measured vapor–liquid equilibrium data were modeled adopting the non-random two-liquid (NRTL) excess Gibbs energy model with the RK (Redlich–Kwong) equation of state. The NRTL binary interaction parameter optimization was carried out employing own measured data and literature data for the toluene + styrene system. The applied model correlates well with the experimental data at the pressure range of 101–30 kPa. Moreover, the NRTL binary parameter regression was performed applying own measured data and literature data separately for the styrene + α-methylstyrene system. The model fitted with the parameters obtained from own measured data described the multiphase behavior of the system better than the parameters obtained from literature data. Additionally, the binary systems showed ideal behavior over the whole range of investigation as the calculated activity coefficients approached unity and no azeotropes were observed.

Isobaric Vapor–Liquid Equilibrium Experiment of N-Propanol and N-Propyl Acetate at 101.3 kPa

N-Propanol (NPA) and n-propyl acetate (NPAC) can form an azeotrope under normal pressure, so their separation cannot be carried out by conventional distillation. Therefore, 1-butyl-3-methylimidazole acetate ([BMIM][OAC]) and ethylene glycol (EG) were selected as entrainers for extractive distillation of the two substances. Isobaric vapor–liquid equilibrium data were obtained by experiments of NPA + NPAC, NPA + NPAC + [BMIM][OAC], and NPA + NPAC + EG at normal pressure; the experimental results showed that the separation effect of [BMIM][OAC] is significantly better than that of EG. Finally, the data were fitted and correlated with the NRTL model. The ARD (average relative deviation) of NPA + NPAC, NPA + NPAC + [BMIM][OAC], and NPA + NPAC + EG is less than 5%, indicating that the NRTL model has good applicability to the vapor–liquid system.

Isobaric Vapor-Liquid Equilibrium Data for Tetrahydrofuran + Acetic Acid and Tetrahydrofuran + Trichloroethylene Mixtures.

Vapor-liquid equilibrium (VLE) data for the binary systems tetrahydrofuran (THF) + acetic acid (AA) and THF + trichloroethylene (TCE) were measured under isobaric conditions using an ebulliometer. The boiling temperatures for the systems (THF + AA/THF + TCE) are reported for 13/15 compositions and five/six different pressures ranging from 50.2/60.0 to 101.1/101.3 kPa, respectively. The THF + AA system shows simple phase behavior with no azeotrope formation. The THF + TCE system does not exhibit azeotrope formation but seems to have a pinch point close to the pure end of TCE. The nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models were used to accurately fit the binary (PTx) data. Both models were able to fit the binary VLE data satisfactorily. However, the NRTL model was found to be slightly better than UNIQUAC model in fitting the VLE data for both systems. The results can be used for designing liquid-liquid extraction and distillation processes involving mixtures of THF, AA, and TCE.

Isobaric Vapor–Liquid Equilibria of Binary Systems Containing Oxygenated Biofuel Compounds (Ethanol + Cyclopentanone, Propyl Butanoate + 4-Methylphenol, Cyclopentanone + Propane-1,2-diol) at Atmospheric Pressure

The isobaric phase equilibrium data for the binary systems of ethanol + cyclopentanone, propyl butanoate + 4-methylphenol, and cyclopentanone + propane-1,2-diol at atmospheric pressure were measured using a modified distillation apparatus. The Herington and Van Ness tests were employed to confirm the thermodynamic consistency of the experimental data. In addition, the Wilson, NRTL, and UNIQUAC models were used to correlate experimental vapor–liquid equilibrium data. The corresponding binary interaction parameters (BIPs) for the three models, which are useful for the modeling and designing separation processes involving biofuel, were obtained using a maximum likelihood objective function. It has been confirmed that when appropriate BIPs are used in each model, the outputs are consistent with each other and with experimental data.

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 %.

Experimental VLE Data of Binary Systems of Ester + Alcohol at 0.6 MPa. Verification using new Association Parameters for the Point– to–Point Test

Experimental data of vapor–liquid equilibria (VLE) are reported for the following binary systems: butyl acetate+ethanol, butyl acetate+1–propanol and butyl acetate+1–butanol at 0.6 MPa. No azeotrope was found in the butyl acetate+1–butanol system at 0.6 MPa. The thermodynamic consistency of the obtained data was analyzed using some equations of state (EOS) in the point–to–point test. The phase behavior was satisfactorily modelled using the Peng–Robinson EOS. The new association parameter of the Hayden–O’Connell method was determined from 144 pure substances and the influence of the second virial coefficient calculations in the point–to–point test was evaluated.

Separation of ethylene glycol, 1,2‐butanediol and 1,2‐propanediol with azeotropic distillation

Abstract1,2‐butanediol (1,2‐BDO) and 1,2‐propanediol (1,2‐PDO) are inevitably side produced in the ethylene glycol (EG) production processes from non‐petroleum routes, but are very difficult to separate by the ordinary distillation method because of the closeness of their boiling temperatures to EG, thus compromise the economy of these processes. The azeotropic distillation process using 1‐octanol (CPO) as an entrainer to separate EG and 1,2‐BDO mixture with or without 1,2‐PDO was studied in this paper. Four binary vapour–liquid equilibrium data of EG‐1,2‐BDO, EG‐CPO, 1,2‐BDO‐CPO, and 1,2‐PDO‐CPO were measured using an Ellis equilibrium kettle and regressed with the thermodynamic model of non‐random two liquid to obtain the corresponding binary interaction parameters. On this basis, azeotropic distillations with CPO as an entrainer were designed to separate EG and 1,2‐BDO with or without 1,2‐PDO. The complete separation processes, including the azeotropic distillation and CPO recovery process consisting of extraction with H2O and subsequent distillation, were simulated and optimized with Aspen Plus for both the EG‐1,2‐BDO binary mixture and the EG‐1,2‐BDO‐1,2‐PDO ternary mixture. The simulation results show that the azeotropic distillation method with CPO as an entrainer can effectively separate the mixture of EG‐1,2‐BDO and EG‐1,2‐BDO‐1,2‐PDO, achieving EG of 99.90% purity with 99.98% recovery and 1,2‐BDO of 99.30% purity with 99.45% recovery for the binary mixture, and achieving EG of 99.90% purity with 99.80% recovery, 1,2‐BDO of 99.35% purity with 99.35% recovery, and 1,2‐PDO of 90.59% purity with 94.38% recovery for the ternary mixture. These processes are promising for industrial application and can significantly improve the economy of non‐petroleum EG production.

The Vapor-Liquid Equilibrium of Bromine-Brine System at Atmospheric Pressure

The air blow-out method of extracting bromine from seawater or brine is widely used at home and abroad. The key parameter in this unit operation is the vapor-liquid equilibrium data (T, x, y) for brominebrine system, which were obtained with the Bubble Equilibrium equipment at 10 and 20℃ in this paper. The experimental equilibrium data were carried out by using Margules Equation for liquid phase and ideal equation for gas phase, and the nonlinear least square method was used to regress the parameters of Margules model for the system. It showed good consistency for the calculated data from Margules model and the experimental data.