Properties component

Tj. is the reduced temperature, T is the critical temperature, is the critical pressure, and is the modified Rackett parameter as given in the supplemental table for pure-component properties. 

Principle components Property advantages Apphcations References... 

A variety of equations-of-state have been applied to supercritical fluids, ranging from simple cubic equations like the Peng-Robinson equation-of-state to the Statistical Associating Fluid Theoiy. All are able to model nonpolar systems fairly successfully, but most are increasingly chaUenged as the polarity of the components increases. The key is to calculate the solute-fluid molecular interaction parameter from the pure-component properties. Often the standard approach (i.e. corresponding states based on critical properties) is of limited accuracy due to the vastly different critical temperatures of the solutes (if known) and the solvents other properties of the solute... 

A theory of regular solutions leading to predictions of solution thermodynamic behavior entirely in terms of pure component properties was developed first by van Laar and later greatly improved by Scatchard [109] and Hildebrand [110,1 11 ]. It is Scatchard-Hildebrand theory that will be briefly outlined here. Its point of departure is the statement that It is next assumed that the volume... 

A wide variety of physical properties are important in the evaluation of ionic liquids (ILs) for potential use in industrial processes. These include pure component properties such as density, isothermal compressibility, volume expansivity, viscosity, heat capacity, and thermal conductivity. However, a wide variety of mixture properties are also important, the most vital of these being the phase behavior of ionic liquids with other compounds. Knowledge of the phase behavior of ionic liquids with gases, liquids, and solids is necessary to assess the feasibility of their use for reactions, separations, and materials processing. Even from the limited data currently available, it is clear that the cation, the substituents on the cation, and the anion can be chosen to enhance or suppress the solubility of ionic liquids in other compounds and the solubility of other compounds in the ionic liquids. For instance, an increase in allcyl chain length decreases the mutual solubility with water, but some anions ([BFJ , for example) can increase mutual solubility with water (compared to [PFg] , for instance) [1-3]. While many mixture properties and many types of phase behavior are important, we focus here on the solubility of gases in room temperature IFs. 

Of course, a primary concern for any physical property measurement, including gas solubility, is the purity of the sample. Since impurities in ILs have been shown to affect pure component properties such as viscosity [10], one would anticipate that impurities might affect gas solubilities as well, at least to some extent. Since ILs are hygroscopic, a common impurity is water. There might also be residual impurities, such as chloride, present from the synthesis procedure. Surprisingly though, we found that even as much as 1400 ppm residual chloride in l-n-octyl-3-methylimi-dazolium hexafluorophosphate and tetrafluoroborate ([OMIM][PFg] and [OMIM] [BF4]) did not appear to have any detectable effect on water vapor solubility [1]. 

For each binary pair, there are two adjustable parameters that must be determined from experimental data, that is, (uy - ujj), which are temperature dependent. Pure component properties rl and ql measure molecular van der Waals volumes and surface areas and have been tabulated6. 

The two adjustable parameters, (u 2 - u22) and ( 2i - n), must be determined experimentally6. Pure component properties rx,r2, qi and q2 have been tabulated6. 

An example is the get/set method pattern used in JavaBeans for component properties. 

CAMD Using a Linear GC-Method for the Prediction of Pure Component Properties Application to Solvent Selection... 

Determine a set of pure component properties (design targets) of the solvent under replacement (specify the goal values for the properties together with upper and lower bounds)... 

Stefanis, E., L. Constantinou, and C. Panayiotou, "Accurate Group-Contribution Method for Predicting Pure Component Properties of Biochemical and Safety Interest", Industrial and Engineering Chemistry Research, 43, 6253-6262, (2004)... 

The solubility values are functions of pure component properties of the solute (a// /uv, 7ffl ) and the liquid phase activity coefficients of the components in solution. Solubility is calculated using the following equation... 

This sub-problem considers the pure component properties. This sub-problem is also a function of binary variables alone (because these constraints only handle primary structure based properties). The feasible molecular structures from Subproblem 1 are solved for the pure component properties. Those molecules, which satisfy the pure component property constraints, are then passed into subproblem 3. 

This sub-problem considers the mixture properties. Mixture properties can be categorized into two types. Properties such as selectivity, solvent power etc., are based on infinite dilution activity coefficients, which are independent of composition and hence only structural information is needed for their calculation. Properties such as complete or partial miscibility of solvent with another constituent is handled by discritizing the composition range from 0 to 1 into n divisions and verifying the miscibility criterion at those points. The difference between pure component property constraints and mixture property constraints is that the former are linear and the latter are non-linear. Those satisfying the mixture property constraints are further analyzed in sub-problem 4. 

Sub-problem 2M considers the pure component property constraints where the compounds from sub-problem 1M are evaluated for the pure component properties. All the molecules satisfying these constraints are passed onto subproblem 3m... 

Pure component property group contribution model parameters ... 

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