Salt-forming regions for a complex salt-water system in non-equilibrium state of evaporation process are usually different from those in solubility diagrams.To understand the solid-forming region of NaCl and improve t...Salt-forming regions for a complex salt-water system in non-equilibrium state of evaporation process are usually different from those in solubility diagrams.To understand the solid-forming region of NaCl and improve the utilization of bittern resources,experiments were carried out to evaporate 20 representative mixture solution samples of Na +,Mg 2+ //Cl-,2 4 SO-H2O system with an average evaporation intensity of(1.4±0.4) g·L-1 ·min-1(water) at boiling temperature 348 K,and determine the NaCl solid-forming regions in non-equilibrium state.Because of the complexity of salt-forming region,a maximal region and a minimal region were proposed to express the non-equilibrium state salt-forming region with different crystal seed,and a conditional salt-forming region was proposed to present the characteristic region of non-equilibrium salt-forming phase diagram.The areas of the maximal and minimal regions are 2.00 and 1.56 times those in solubility diagram,so it is possible to utilize bittern resources in high efficiency.The recovery rates of NaCl were 99.65%,93.14%,88.57%,72.76%,and 83.68%for six typical bittern sources from Tulantai Salt Lake(China),Dongtai Salt Lake(China) ,Jilantai Salt Lake(China),Qarun Salt Lake(Egypt) and seawater,respectively.It is testified that the non-equilibrium state salt-forming phase diagram can be used in industrial processes.展开更多
A new non-cubic equation of state is proposed for calculation of the thermodynamic properties ofnonpolar and polar fluids and their mixtures,including,saturated vapor pressure,saturated liquid volume,saturated vapor v...A new non-cubic equation of state is proposed for calculation of the thermodynamic properties ofnonpolar and polar fluids and their mixtures,including,saturated vapor pressure,saturated liquid volume,saturated vapor volume,heats of vaporization and vapor-liquid equilibria.The new equation is derived from thegeneralized van der Waals partition function in which the repulsive terms are expressed with the Carnahan andStarling equation for hard spheres,and the attractive terms are made up of the dispersive energy and theChemical association energy. The rules of dependence of parameters α and σ and on temperature are considered broadly so that the newequation yields good agreement with experimental saturated properties of 20 nonpolar and 27 polar fluids in therange of reduced temperatures of 0.5 to 1.0 The new equation with parameters group-contributed generally givessatisfactory predictions on saturated properties. Correlations of vapor-liquid equilibrium data for alcohol-containing systems by using van展开更多
Here we review a new class of mixing rules that have extended range of mixtures and condi-tions that can now be described by equation of state models.One characteristic of these mixing rulesis that they simultaneously...Here we review a new class of mixing rules that have extended range of mixtures and condi-tions that can now be described by equation of state models.One characteristic of these mixing rulesis that they simultaneously satisfy the boundary conditions of producing a second virial coefficientthat is quadratic in mole fraction,and a free energy of mixing like that of an activity coefficientmodel at high density,though the mixing rule is itself independent of density.We show that usingthis mixing rule,various asymmetric,highly nonideal mixtures can be accurately described.Oneserendipitous result is that the parameters in this mixing rule model are almost independent oftemperature,which allows accurate extrapolations of phase behavior to be made over large ranges oftemperature and pressure.展开更多
The phase equilibrium data of CO2 hydrocarbon binary mixtures are important for the design and operation of CO 2 ood- ing, coal liquefaction, and supercritical extraction processes. Numerous pieces of binary phase equ...The phase equilibrium data of CO2 hydrocarbon binary mixtures are important for the design and operation of CO 2 ood- ing, coal liquefaction, and supercritical extraction processes. Numerous pieces of binary phase equilibrium data have been obtained. Thus, models for the accurate calculation of binary and multicomponent mixtures must be developed on the basis of existing data. In this work, 3578 vapor liquid phase equilibrium data points for 10 CO 2 hydrocarbon binary mixtures, including CO2 butane, CO 2 pentane, CO 2 isopentane, C O 2 hexane, CO 2 benzene, CO 2 heptane, CO 2 octane, C O 2 non- ane, CO 2 decane, and C O 2 undecane, were collected. The PR and PR-BM equations of state (EOS) in combination with relevant mixing rules were used to calculate the phase equilibrium data of the CO 2 hydrocarbon binary mixtures. The binary interaction parameter k ij in the PR EOS was temperature independent, whereas parameters in the PR-BM EOS were functions of temperature. Thus, the phase equilibrium data and other thermodynamic properties of the binary and multicomponent mixtures at di erent temperatures and pressures can be calculated by using the parameters obtained in this work. The PR-BM EOS performed better than the PR EOS, and the average absolute deviations over the temperature range of 255.98 408.15 K calculated by the PR EOS and PR-BM EOS were less than 5.74% and 3.36%, respectively. The results calculated by the two EOS were compared with those calculated by other models, such as PPR78, PR + LCVM + UNIFAC, KIE + PR EOS + HV, and PSRK. The phase equilibrium data of CO 2 butane decane, CO 2 hexane decane, and C O 2 octane decane ternary mixtures were calculated by the two EOS. The average overall deviations for the CO 2 mole fractions calculated by the two EOS were less than 7.66%.展开更多
A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temp...A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temperature and pressure range.Combined with a modified Huron-Vidal gE-mixing rule it was applied for modeling vapor-liquid equilibria of polymer-solvent solutions and the solubility of supercritical gases in polymer melts.Satisfactory results are obtained.展开更多
基金Supported by the National Natural Science Foundation of China（20776110） the Natural Science Foundation of Tianjin（06YFJMJC04100）
文摘Salt-forming regions for a complex salt-water system in non-equilibrium state of evaporation process are usually different from those in solubility diagrams.To understand the solid-forming region of NaCl and improve the utilization of bittern resources,experiments were carried out to evaporate 20 representative mixture solution samples of Na +,Mg 2+ //Cl-,2 4 SO-H2O system with an average evaporation intensity of(1.4±0.4) g·L-1 ·min-1(water) at boiling temperature 348 K,and determine the NaCl solid-forming regions in non-equilibrium state.Because of the complexity of salt-forming region,a maximal region and a minimal region were proposed to express the non-equilibrium state salt-forming region with different crystal seed,and a conditional salt-forming region was proposed to present the characteristic region of non-equilibrium salt-forming phase diagram.The areas of the maximal and minimal regions are 2.00 and 1.56 times those in solubility diagram,so it is possible to utilize bittern resources in high efficiency.The recovery rates of NaCl were 99.65%,93.14%,88.57%,72.76%,and 83.68%for six typical bittern sources from Tulantai Salt Lake(China),Dongtai Salt Lake(China) ,Jilantai Salt Lake(China),Qarun Salt Lake(Egypt) and seawater,respectively.It is testified that the non-equilibrium state salt-forming phase diagram can be used in industrial processes.
文摘A new non-cubic equation of state is proposed for calculation of the thermodynamic properties ofnonpolar and polar fluids and their mixtures,including,saturated vapor pressure,saturated liquid volume,saturated vapor volume,heats of vaporization and vapor-liquid equilibria.The new equation is derived from thegeneralized van der Waals partition function in which the repulsive terms are expressed with the Carnahan andStarling equation for hard spheres,and the attractive terms are made up of the dispersive energy and theChemical association energy. The rules of dependence of parameters α and σ and on temperature are considered broadly so that the newequation yields good agreement with experimental saturated properties of 20 nonpolar and 27 polar fluids in therange of reduced temperatures of 0.5 to 1.0 The new equation with parameters group-contributed generally givessatisfactory predictions on saturated properties. Correlations of vapor-liquid equilibrium data for alcohol-containing systems by using van
文摘Here we review a new class of mixing rules that have extended range of mixtures and condi-tions that can now be described by equation of state models.One characteristic of these mixing rulesis that they simultaneously satisfy the boundary conditions of producing a second virial coefficientthat is quadratic in mole fraction,and a free energy of mixing like that of an activity coefficientmodel at high density,though the mixing rule is itself independent of density.We show that usingthis mixing rule,various asymmetric,highly nonideal mixtures can be accurately described.Oneserendipitous result is that the parameters in this mixing rule model are almost independent oftemperature,which allows accurate extrapolations of phase behavior to be made over large ranges oftemperature and pressure.
基金supported by the National Key Research and Development Program of China (2016YFB0600804-3)Shandong Natural Science Foundation (ZR2017BB076)
文摘The phase equilibrium data of CO2 hydrocarbon binary mixtures are important for the design and operation of CO 2 ood- ing, coal liquefaction, and supercritical extraction processes. Numerous pieces of binary phase equilibrium data have been obtained. Thus, models for the accurate calculation of binary and multicomponent mixtures must be developed on the basis of existing data. In this work, 3578 vapor liquid phase equilibrium data points for 10 CO 2 hydrocarbon binary mixtures, including CO2 butane, CO 2 pentane, CO 2 isopentane, C O 2 hexane, CO 2 benzene, CO 2 heptane, CO 2 octane, C O 2 non- ane, CO 2 decane, and C O 2 undecane, were collected. The PR and PR-BM equations of state (EOS) in combination with relevant mixing rules were used to calculate the phase equilibrium data of the CO 2 hydrocarbon binary mixtures. The binary interaction parameter k ij in the PR EOS was temperature independent, whereas parameters in the PR-BM EOS were functions of temperature. Thus, the phase equilibrium data and other thermodynamic properties of the binary and multicomponent mixtures at di erent temperatures and pressures can be calculated by using the parameters obtained in this work. The PR-BM EOS performed better than the PR EOS, and the average absolute deviations over the temperature range of 255.98 408.15 K calculated by the PR EOS and PR-BM EOS were less than 5.74% and 3.36%, respectively. The results calculated by the two EOS were compared with those calculated by other models, such as PPR78, PR + LCVM + UNIFAC, KIE + PR EOS + HV, and PSRK. The phase equilibrium data of CO 2 butane decane, CO 2 hexane decane, and C O 2 octane decane ternary mixtures were calculated by the two EOS. The average overall deviations for the CO 2 mole fractions calculated by the two EOS were less than 7.66%.
基金Supported by the Zhejiang Provincial Foundation for Returned Scholarsthe Scientific Research Foundation of the State Human Resource Ministry.
文摘A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temperature and pressure range.Combined with a modified Huron-Vidal gE-mixing rule it was applied for modeling vapor-liquid equilibria of polymer-solvent solutions and the solubility of supercritical gases in polymer melts.Satisfactory results are obtained.
