Gas-liquid critical temperatures of mixtures containing an organosilicon compound

1978 ◽  
Vol 31 (5) ◽  
pp. 957 ◽  
Author(s):  
SD Waterson ◽  
CL Young
Keyword(s):  
Critical Temperature ◽  
Equation Of State ◽  
Hard Sphere ◽  
Organosilicon Compound ◽  
Composition Dependence ◽  
Fluid Model ◽  
Iterative Solution ◽  
Critical Temperatures ◽  
Temperature And Pressure ◽  
The One

The gas-liquid critical temperatures of 16 binary mixtures containing an organosilicon compound have been measured by the sealed-tube method, together with the gas-liquid critical temperature and pressure of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane.��� The results for the mixtures have been used to calculate a parameter characterizing the interactions between unlike molecules. An iterative solution to the criticality condition was used together with the one-fluid model and a 'hard sphere+attractive term' equation of state. ��� The interaction parameters are discussed briefly. The one-fluid model in the form used here, at least, appears to be unsatisfactory for predicting the composition dependence of the gas-liquid critical temperatures within 5 K for mixtures of molecules of widely differing sizes (i.e. size ratios as estimated from molar volumes of greater than 1 : 4).

Upper critical solution temperatures of hydrocarbon + fluorocarbon mixtures : mixtures with specific interactions

1980 ◽  
Vol 33 (3) ◽  
pp. 465 ◽  
Author(s):  
LS Toczylkin ◽  
CL Young
Keyword(s):  
Equation Of State ◽  
Interaction Energy ◽  
Hard Sphere ◽  
Fluid Model ◽  
Energy Parameter ◽  
Specific Interactions ◽  
The One ◽  
Critical Solution Temperatures

The upper critical solution temperatures of a series of compounds with perfluorotributylamine and with perfluorocyclohexene are reported. From these results the interaction energy parameter, ξ, has been calculated by using a hard sphere+attractive term equation of state, together with the one-fluid model. The values of ξ for these mixtures and a few calculated from literature upper critical solution temperatures have been discussed in terms of possible specific interactions between pairs of unlike molecules.

Gas-gas immiscibility in hydrogen mixtures

1984 ◽  
Vol 37 (1) ◽  
pp. 29
Author(s):  
BN Missen ◽  
CL Young
Keyword(s):  
Equation Of State ◽  
Critical Point ◽  
Binary Mixtures ◽  
Interaction Parameter ◽  
Hard Sphere ◽  
Fluid Model ◽  
Critical Locus ◽  
Energy Interaction ◽  
Hydrogen Mixtures ◽  
The One

Measurements are reported of the slope of the critical locus of binary mixtures of a series of hydrocarbons, and two fluorocarbons, with hydrogen near the critical point of the hydrocarbon (or fluorocarbon).These systems exhibit gas-gas immiscibility of the first kind. The results are compared with predictions from the one-fluid model together with 'a hard sphere + attractive term' equation of state proposed by Guggenheim. The results can be predicted from the theory provided the energy interaction parameter, ξ, is allowed to be somewhat less than that calculated from the Hudson and McCoubrey rule. This is discussed in terms of values of ξ from other measurements, and possible deficiencies in the theory.

Equations of state for fluids based on hard sphere repulsion

2015 ◽  
Vol 29 (13) ◽  
pp. 1550089 ◽  
Author(s):  
Minhui Shan ◽  
Jianxiang Tian
Keyword(s):  
Equation Of State ◽  
Thermodynamic Properties ◽  
Hard Sphere ◽  
Equations Of State ◽  
The Past ◽  
Complex Interactions ◽  
Structures And Properties ◽  
The One ◽  
Real Fluids

As is well-known, the structures and thermodynamic properties of fluids are determined by the complex interactions, i.e., the repulsive one and the attractive one, among particles. The simplest equation-of-state (EOS) model maybe the one of hard sphere repulsion plus or multiplying some attraction. Followed by the rapid promotion of the accuracy of hard sphere EOS in the past dozens of years, one question rises as whether more accurate hard sphere repulsion derives better prediction of the structures and properties of fluids with a special attraction. In this work, we used two repulsions with clearly different accuracy and some attractions to construct series equations of state (EOSs) for real fluids, and then we discussed the saturated properties at liquid–gas equilibrium. We found that the answer to the question aforementioned is not definitely standing.

Thermodynamic excess functions of regular and related solutions according to some equations of state based on the perturbed hard sphere model

1973 ◽  
Vol 26 (10) ◽  
pp. 2071 ◽  
Author(s):  
DK Astin ◽  
ID Watson
Keyword(s):  
Equation Of State ◽  
Hard Sphere ◽  
Equations Of State ◽  
Fluid Model ◽  
Quantitative Agreement ◽  
Excess Functions ◽  
Hard Sphere Model ◽  
Thermodynamic Excess Functions ◽  
Two Fluid Model ◽  
Two Fluid

The excess thermodynamic functions of 12 mixtures, each representative of a certain type of system, have been calculated by means of the van der Waals, Frisch,1 and Carnahan and Starling2 equation of state, in conjunction with one-fluid and two-fluid models of conformal mixtures. In addition, the equation of state of hard sphere mixtures of Mansoori et al.3 has been used. Though none of the approaches give quantitative agreement for any of the systems considered, they all give a qualitative account which broadly reflect the trends in behaviour. In the cases where it is appropriate to comment on the qualitative accuracy the two-fluid model, used with either the Frisch or Carnahan and Starling equation of state, shows a slight superiority to the others.

Comparison of the values of the interaction parameter ξ from upper critical solution temperatures of acetone + alkanes with values obtained from gas-liquid critical temperatures

1977 ◽  
Vol 30 (4) ◽  
pp. 767 ◽  
Author(s):  
LS Toczylkin ◽  
CL Young
Keyword(s):  
Equation Of State ◽  
Interaction Parameter ◽  
Fluid Model ◽  
Van Der Waals ◽  
Critical Temperatures ◽  
Acetone Hexane ◽  
Critical Solution Temperatures

The upper critical solution temperatures, UCST , of acetone + alkane (n- C5H12 to n-C17H36) and acetone + hexane isomers have been measured. These results are used to calculate an interaction parameter ξ by using the van der Waals one-fluid model together with the Guggenheim equation of state. Values of ξ are compared with those obtained from the gas-liquid critical temperatures. The gas-liquid critical temperatures for the n- alkane + acetone systems were taken from the literature whereas those for the hexane isomers + acetone were measured in this work. The values of ξ calculated from gas-liquid critical temperatures are slightly greater than those calculated from the UCST as has been observed previously for other systems.

PHYSICAL TEMPERATURE AND PRESSURE IN FULLY NONEXTENSIVE STATISTICAL THERMODYNAMICS

2008 ◽  
Vol 11 (01) ◽  
pp. 43-54 ◽  
Author(s):  
VIOREL BADESCU
Keyword(s):  
Equation Of State ◽  
Statistical Thermodynamics ◽  
Additive Functions ◽  
New Approach ◽  
Thermodynamic Entropy ◽  
Classical Gas ◽  
Nonextensive Thermodynamics ◽  
Temperature And Pressure ◽  
The One ◽  
Definition Of

This paper generalizes previous results concerning the definitions of physical temperature and pressure in nonextensive statistical thermodynamics. The novelty is that both the internal energy and the volume are no longer additive functions. The new approach is referred to as "fully" nonextensive thermodynamics. The physical temperature is different from the inverse of the Lagrange multiplier. This fact changes the form of some usual thermodynamic relations. For example, the Clausius definition of the thermodynamic entropy has to be modified. As an application, the classical gas model is examined with statistical calculations performed under the Tsallis–Mendes–Plastino formalism of nonextensive thermodynamics. The specific heat expression differs from the one encountered in ordinary extensive thermodynamics but the equation of state keeps the same form.

scholarly journals Equation of State of Four- and Five-Dimensional Hard-Hypersphere Mixtures

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 469 ◽  
Author(s):  
Mariano López de Haro ◽  
Andrés Santos ◽  
Santos B. Yuste
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo Simulation ◽  
Equation Of State ◽  
Hard Sphere ◽  
Virial Coefficient ◽  
Three Dimensional ◽  
The Other ◽  
Third Virial Coefficient ◽  
Simulation Results ◽  
The One

New proposals for the equation of state of four- and five-dimensional hard-hypersphere mixtures in terms of the equation of state of the corresponding monocomponent hard-hypersphere fluid are introduced. Such proposals (which are constructed in such a way so as to yield the exact third virial coefficient) extend, on the one hand, recent similar formulations for hard-disk and (three-dimensional) hard-sphere mixtures and, on the other hand, two of our previous proposals also linking the mixture equation of state and the one of the monocomponent fluid but unable to reproduce the exact third virial coefficient. The old and new proposals are tested by comparison with published molecular dynamics and Monte Carlo simulation results and their relative merit is evaluated.

A PROPERTY OF THE SATURATED VAPOR PRESSURE: RESULTS FROM EQUATIONS OF STATE

2009 ◽  
Vol 23 (26) ◽  
pp. 3091-3096 ◽  
Author(s):  
JIANXIANG TIAN ◽  
HUA JIANG ◽  
YI XU
Keyword(s):  
Critical Temperature ◽  
Equation Of State ◽  
Vapor Pressure ◽  
Hard Sphere ◽  
Critical Pressure ◽  
Equations Of State ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Maximum Point ◽  
Critical Amplitudes

Experimentally, a maximum point in the curve of the saturated property ψ=(1-Tr)Pr versus the saturated temperature was postulated (High Temp.-High Press.26 (1994) 427). Here, Tr is the saturated temperature reduced by the critical temperature and Pr is the saturated pressure reduced by the critical pressure. Later, this behavior was applied to assure the saturated vapor pressure critical amplitudes (Appl. Phys. Lett.90 (2007) 141905). In this paper, we indicate that theory of equation of state (EOS) can predict this maximum point. The EOSs we study are the combinations of the hard sphere repulsions and some normally used attractions such as the Redlich–Kwong attraction. We find the EOSs with Redlich–Kwong attractive terms give out the results in the experimental range.

The phase behaviour of binary mixtures containing hydrogen

1983 ◽  
Vol 36 (10) ◽  
pp. 2005 ◽  
Author(s):  
AK Burgess ◽  
CL Young
Keyword(s):  
Small Molecules ◽  
Equations Of State ◽  
Fluid Model ◽  
Phase Behaviour ◽  
Critical Temperatures ◽  
Higher Hydrocarbons ◽  
The One ◽  
Hydrogen Systems ◽  
Permanent Gases ◽  
Best Fit

The solubility and gas-liquid critical temperatures of mixtures of hydrogen with the permanent gases has been discussed in terms of the one-fluid model and 'hard sphere + attractive term' equations of state as proposed by Carnahan and Starling and Guggenheim. The solubilities of hydrogen and 'moderately-sized' hydrocarbons such as benzene and cyclohexane and higher hydrocarbons such as decalin and bicyclohexyl have also been discussed in terms of the one-fluid model. Finally, examples of the solubilities of other small molecules, methane, nitrogen and carbon dioxide, in both 'moderately sized' and higher hydrocarbons are considered in terms of the one-fluid model. It is concluded that : (A) The best fit values of the interaction parameter, ζ, for all mixtures, except the permanent gas+ hydrogen systems, are considerably smaller than predicted by the Hudson and McCoubrey rule. (B) The values of ζ for the hydrogen+ hydrocarbon mixtures are considerably smaller than those for similar hydrocarbons + other small molecules. (c) Often the best fit value of ζ decreases with an increase in temperature.

Testing a simple method for computing directly the bulk modulus by NPT simulation: The case of polydisperse hard sphere solids

2015 ◽  
Vol 26 (05) ◽  
pp. 1550057
Author(s):  
Da Li ◽  
Hong Xu
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Bulk Modulus ◽  
Hard Sphere ◽  
Solid Phase ◽  
Component Mixture ◽  
Simple Method ◽  
Illustrative Purpose ◽  
The One ◽  
Pressure Regime

The bulk modulus of hard sphere solids has been computed directly by constant pressure Monte-Carlo simulations, using the histogram of the volume fluctuations. In considering first the one-component system, we show that the method is accurate in a large range of pressures, including high-pressure regime. The method is then applied to a polydisperse solid with relatively low polydispersity index. For illustrative purpose, we took a three-component mixture with symmetric size-distribution, and we studied the solid phase (fcc crystal) of this system. Our results show that the equation of state is very sensitive to the polydispersity. Furthermore, in the high-pressure region, where no (accurate) analytical fit for the equation of state exists, our simulations are able to predict the bulk modulus of such systems.

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