通过状态方程预测无定形和可结晶共混聚合物的压力-体积-温度和超摩尔体积（英文）

In this work the statistical mechanical equation of state was developed for volumetric properties of crystal ine and amorphous polymer blends. The Ihm–Song–Mason equations of state (ISMEOS) based on temperature and density at melting point (Tm andρm) as scaling constants were developed for crystalline polymers such as poly(propylene glycol)+poly(ethylene glycol)-200 (PPG+PEG-200), poly(ethylene glycol) methyl ether-300 (PEGME-350)+PEG-200 and PEGME-350+PEG-600. Furthermore, for amorphous polymer blends con-taining poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)+polystyrene (PS) and PS+poly(vinylmethylether) (PVME), the density and surface tension at glass transition (ρg andγg) were used for estimation of second Virial coefficient. The calculation of second Virial coefficients (B2), effective van der Waals co-volume (b) and correction factor (α) was required for judgment about applicability of this model. The obtained results by ISMEOS for crys-talline and amorphous polymer blends were in good agreement with the experimental data with absolute aver-age deviations of 0.84%and 1.04%, respectively.     

化工过程基于广义非线性状态观测器的不可测输入和不确定模型参数软仪表(英文)

Chemical processes are usually nonlinear singular systems. In this study, a soft sensor using nonlinear singular state observer is established for unknown inputs and uncertain model parameters in chemical processes, which are augmented as state variables. Based on the observability of the singular system, this paper presents a simplified observability criterion under certain conditions for unknown inputs and uncertain model parameters. When the observability is satisfied, the unknown inputs and the uncertain model parameters are estimated online by the soft sensor using augmented nonlinear singular state observer. The riser reactor of fluid catalytic cracking unit is used as an example for analysis and simulation. With the catalyst circulation rate as the only unknown input without model error, one temperature sensor at the riser reactor outlet will ensure the correct estimation for the catalyst cir- culation rate. However, when uncertain model parameters also exist, additional temperature sensors must be used to ensure correct estimation for unknown inputs and uncertain model parameters of chemical processes.     

Prediction of Henry's constant in polymer solutions using PCOR equation of state coupled with an activity coefficient model

In this paper, the polymer chain of rotator (PCOR) equation of state (EOS) was used together with an EOS/GE mixing rule (MHV1) and the Wilson's equation as an excess-Gibbs-energy model in the proposed ...     

Correlation of the mean activity coefficient of aqueous electrolyte solutions using an equation of state

Accurate calculation of thermodynamic properties of electrolyte solution is essential in the design and optimization of many processes in chemical industries.A new electrolyte equation of state is developed for aqueous electrolyte solutions.The Carnahan–Starling repulsive model and an attractive term based on square-well potential are adopted to represent the short range interaction of ionic and molecular species in the new electrolyte EOS.The long range interaction of ionic species is expressed by a simplified version of Mean Spherical Approximation theory(MSA).The new equation of state also contains a Born term for charging free energy of ions.Three adjustable parameters of new e EOS per each electrolyte solution are size parameter,square-well potential depth and square-well potential interaction range.The new e EOS is applied for correlation of mean activity coefficient and prediction of osmotic coefficient of various strong aqueous electrolyte solutions at 25 °C and 0.1 MPa.In addition,the extension of the new e EOS for correlation of mean activity coefficient and solution density of a few aqueous electrolytes at temperature range of 0 to 100 °C is carried out.     

Prediction of thermodynamic properties of polymeric liquids using a new equation of state

In this paper, we have used a simple equation of state (EoS) to predict the density for polymeric liquid mixtures at different temperatures, pressures, and compositions. The excess molar volumes of these mixtures have been also calculated using this equation of state. Also, we have computed isothermal compressibility. A wide comparison with experimental data has been made for each thermodynamic property. The values of statistical parameters between experimental and calculated properties show the ability of this equation of state in reproducing and predicting different thermodynamic properties for studied polymeric mixtures.     

Prediction of thermodynamic properties of aqueous electrolyte solutions using equation of state

In this study, a predictive model is presented for estimation of second order thermodynamic properties of electrolyte solutions. In order to provide a comprehensive understanding, the capability of modified electrolyte PC‐SAFT up to high pressure and temperature has been studied. In addition to the first order derivative thermodynamic properties, the Gibbs free energy, enthalpy and heat capacity of aqueous electrolyte solutions at infinite dilution are predicted. Using new methodology, the dielectric constant is modified to keep the pressure, temperature, and ionic strength dependency. Our results show that the Born term has a significant contribution on prediction of second order derivative properties. Meanwhile the impact of temperature‐dependent solution dielectric constant on standard state heat capacity is studied. Finally, the isobaric heat capacity at various salt concentrations is predicted without any adjustable parameters. The results of this work indicate an acceptable agreement with experimental data especially at high pressure and temperature. © 2017 American Institute of Chemical Engineers AIChE J, 2017     

Extension of Valderrama-Patel-Teja equation of state to modelling single and mixed electrolyte solutions

The Valderrama modification of Patel-Teja equation of state (VPT EoS) has been extended to predicting fluid phase equilibria in the presence of single and mixed electrolyte solutions at high-pressure conditions. Salts have been introduced as components in the EoS by calculating their EoS parameters from corresponding cation and anion parameters. A non-density dependent mixing rule is used for calculating a, b, and c parameters of the EoS. The inclusion of salts in the EoS resulted in the omission of the Debye-Hückel electrostatic contribution term in the fugacity coefficient calculations. Water-salt binary interaction parameters (BIPs) are optimised using freezing point depression and boiling point elevation data of aqueous electrolyte solutions. Gas solubility data in aqueous electrolyte solution are used for optimising salt-gas BIPs. The predictions of the model have been compared with independent experimental data, demonstrating the reliability of the approach.     

应用马丁─侯状态方程计算含氨气体混合物的物性参数

本文将马丁—侯状态方程用于计算气体混合物的恒压热容、粘度和导热系数．含氨气体混合物的恒压热容为理想气体混合物热容与真实气体混合物剩余热容之和，根据剩余粘度法计算粘度，剩余导热系数法计算导热系数．三种压力，不同温度条件下气体混合物恒压热容、粘度和导热系数的计算结果表明：计算值与实验值相吻合．并分别拟合了合成氨生产三种工艺含氨气体混合物恒压热容、粘度、导热系数的计算式。     

Mutual solubility study for 94.2:5.8 of ethanol to octane with supercritical carbon dioxide solvent

Solubility data of a mixture containing 94.2% ethanol and 5.8% octane was measured in carbon dioxide solvent using a high-pressure type phase equilibrium apparatus at pressures up to 103.5 bar and at temperature of 75 °C. The results showed that considerable separation was not achieved in this ethanol and octane ratio. However, the experimental data were then compared with the theoretical data which were obtained from two models which are regular solution theory and Redlich-Kwong equation of state. Regular solution theory is employed to each phase by applying activity coefficient expressions. Redlich-Kwong equation of state is employed to the vapor phase and then with applying fugacity coefficient, liquid phase data is obtained. The regular solution theory as a novel model approach has been found to be encouraging for the prediction of phase equilibria solubilities. It concluded that the regular solution theory model could predict two phases equilibrium data better than Redlich-Kwong equation of state.     

UNIFAC模型与PRSV方程相结合预测二元及三元系统汽液相平衡

采用Ｗｏｎｇ和Ｓａｎｄｌｅｒ混合规则，将ＰＲＳＶ立方型状态方程与ＵＮＩＦＡＣ活度系数模型相结合，给出一种预测混合物相平衡热力学性质的方法，并用５４个二元体系和９个三元体系的实验数据做了检验，结果表明，该法可以较好地预测二元及三元体系的汽液相平衡。