Determination of Perturbed-Chain Statistical Association Fluid Theory Parameters for Pure Substances, Single Carbon Number Groups, and Petroleum Fractions Using Cubic Equations of State Parameters

2015 ◽  
Vol 54 (45) ◽  
pp. 11448-11465 ◽  
Author(s):  
Pouya Hosseinifar ◽  
Saeid Jamshidi
Keyword(s):  
Equations Of State ◽  
Carbon Number ◽  
Statistical Association ◽  
Petroleum Fractions ◽  
Fluid Theory ◽  
Pure Substances ◽  
Statistical Association Fluid Theory

Critical Study of a Residual Viscosity Correlation of JOSSI: Pure Hydrocarbons Case

2020 ◽  
Vol 986 ◽  
pp. 61-67
Author(s):  
Mohamed Jaouad Malzi ◽  
Aziz Ettahir ◽  
Christian Boned ◽  
Bernard Lagourette ◽  
Kamal Kettani ◽  
...  
Keyword(s):  
Equations Of State ◽  
Critical Study ◽  
Average Deviation ◽  
Cubic Equation ◽  
Viscosity Correlation ◽  
Opposite Situation ◽  
Pure Substances ◽  
Reduced Density

The most common residual viscosity correlation used in the petroleum models is JOSSI et al [1] where the residual viscosity is represented by a polynomial function of 4th degree involving the reduced density ρr ([(η-η*)ξ+10-4]1/4=Σ41=0(aiρri)). Based on this formula, it is possible to predict various uncertainties that can be accumulated and thus alter the performance of viscosity restitution which depends on several factors:The quality of the initial adjustment of the coefficients ai;The precision on the density;The accuracy with which are known the characteristics of the constituents of bases;The validity of the rule of the mixtures selected for the determination of the pseudo-critical coordinates Tcm and Pcm and the equivalent molar mass of the mixture.As far as the results are concerned, we reveal that with the new set of coefficients it is possible to obtain a more preciserepresentation compared to that of JOSSI. The method of JOSSI seems to be especially interesting for the viscosities restitution of systems containing light and close paraffins. However, for some pure substances, the opposite situation could be true. Among the four equations-of-state used, it has been found that the cubic equation-of-stateof PENG and ROBINSON should not be used since we would like to generate the density. Finally, we are not expecting a perfect systematic representation. As demonstrated in our model, if for light alkanes one can expect an average deviation ofless than 10%, for certain pure substances the deviation exceeds 20%.

Modeling the Viscosity of Ionic Liquids with the Electrolyte Perturbed-Chain Statistical Association Fluid Theory

2014 ◽  
Vol 53 (52) ◽  
pp. 20258-20268 ◽  
Author(s):  
Gulou Shen ◽  
Christoph Held ◽  
Jyri-Pekka Mikkola ◽  
Xiaohua Lu ◽  
Xiaoyan Ji
Keyword(s):  
Ionic Liquids ◽  
Statistical Association ◽  
Fluid Theory ◽  
Statistical Association Fluid Theory

EQUATIONS OF STATE FOR FLUIDS: THE LIQUID-VAPOR EQUILIBRIUM (LVE)

2008 ◽  
Vol 22 (30) ◽  
pp. 5335-5347 ◽  
Author(s):  
JIANXIANG TIAN ◽  
YUANXING GUI
Keyword(s):  
Experimental Data ◽  
Equations Of State ◽  
Packing Fraction ◽  
Optimal Choice ◽  
Critical Conditions ◽  
Mechanics Model ◽  
Vapor Equilibrium ◽  
Pure Substances ◽  
Compressibility Factors ◽  
Liquid Vapor

Historically, the development of equations of state for fluids has almost invariably followed the lead of the van der Waals (vdW) equation which includes an attraction term and a repulsion term. In this paper, using a simple statistical mechanics model, we introduce a parameter σ as both the power and a coefficient of the packing fraction y which locates at the numerator of the vdW attraction term. Then nine equations of state are constructed to solve the critical conditions and the main thermodynamic properties of pure substances at liquid-vapor equilibrium. As a result, the correct critical compressibility factors of Nitrogen, Argon, Carbon dioxide, Ethene, Methane, Oxygen, Propene, Water and Hydrogen, are obtained with an optimal choice of parameter σ. Good predictions of these equations to the liquid-vapor equilibrium properties below critical temperature are reported and compared with experimental data.

Technique and results of experimental determination of the compressibility factor of the natural gas

2021 ◽  
pp. 35-40
Author(s):  
Denis Y. Kutovoy ◽  
Igor A. Yatsenko ◽  
Vladimir B. Yavkin ◽  
Aydar N. Mukhametov ◽  
Petr V. Lovtsov ◽  
...  
Keyword(s):  
Natural Gas ◽  
Equations Of State ◽  
Compressibility Factor ◽  
High Accuracy ◽  
State Equations ◽  
Actual Problem ◽  
Temperature Range ◽  
Relative Value ◽  
Compressibility Coefficient

The actual problem of the possibility of using the equations of state for the gas phase of natural gas at temperatures below 250 K is considered. To solve it, the compressibility coefficients of natural gas obtained experimentally with high accuracy are required. The technique was developed and experimental study was carried out of compressibility factor aiming expanding temperature range of the state equations GERG-2004 and AGA8-DC92. The proposed technique is based on the fact that to assess the applicability of the equation of state, it is sufficient to obtain the relative value of the compressibility coefficient and not to determine its absolute value. The technique does not require complex equipment and provides high accuracy. The technique was tested on nitrogen, argon, air and methane. Uncertainty of determination of the compressibility factor is not greater than 0.1 %. For two different compositions of natural gas, obtained experimental data were demonstrated that the equations of state GERG-2004 and AGA8-92DC provide uncertainty of the calculation of the compressibility coefficient within 0.1 % in the temperature range from 220 K to 250 K and pressure below 5 MPa.

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