lib.MSRK module

class lib.EoS.Cubic.MSRK.MSRK(T, P, mezcla, **kwargs)

Bases: SRK

Modified SRK two parameters cubic equation of state as explain in [1]

\[\begin{split}\begin{array}[t]{l} P = \frac{RT}{V-b}-\frac{a}{V\left(V+b\right)}\\ a = 0.42747\frac{R^2T_c^2}{P_c}\alpha\\ b = 0.08664\frac{RT_c}{P_c}\\ \alpha = 1 + m\left(1-Tr\right) + n\left(\frac{1}{T_R}-1\right)\\ \end{array}\end{split}\]

m and n are compound specific parameters, compiled from [4] and [5], in case compound with no available parameters use the generalized correlation give in [6].

\[\begin{split}\begin{array}[t]{l} m = 0.4745 + 2.7349\omega Z_c + 6.0984\left(\omega Z_c\right)^2\\ m = 0.0674 + 2.1031\omega Z_c + 3.9512\left(\omega Z_c\right)^2\\ \end{array}\end{split}\]

Examples

Example 4.3 from [2], Propane saturated at 300K

>>> from lib.mezcla import Mezcla
>>> mix = Mezcla(5, ids=[4], caudalMolar=1, fraccionMolar=[1])
>>> eq = MSRK(300, 9.9742e5, mix)
>>> '%0.1f' % ( eq.Vl.ccmol)
'98.2'
>>> eq = MSRK(300, 42.477e5, mix)
>>> '%0.1f' % (eq.Vg.ccmol)
'94.9'

_alfa(cmp, T)

Special alpha function for this modified version, if the compound specified parameters are not available in database use the standard SRK alpha expresion

References

[1]

Soave, G.; Application of a Cubic Equation of State to Vapor-Liquid Equilibria of Systems Containing Polar Compounds, Inst. Chem. Eng. Symp. Ser. 56 (1979) 1.2/1-1.2/16

[2]

Soave, G.; Improvement of the van der Waals Equation of State, Chem. Eng. Sci. 39(2) (1984) 357-369, http://dx.doi.org/10.1016/0009-2509(84)80034-2

[3]

Poling, B.E, Prausnitz, J.M, O’Connell, J.P; The Properties of Gases and Liquids 5th Edition, McGraw-Hill, New York, 2001

[4]

Sandarusi, J.A., Kidnay, A.J., Yesavage, V.F.; Compilation of Parameters for a Polar Fluid Soave-Redlich-Kwong Equation of State, Ind. Eng. Chem. Process Des. Dev. 25(4) (1986) 957-963, http://dx.doi.org/10.1021/i200035a020

[5]

Kadhem, Q.M.A, Al-Sahhaf, T.A., Hamam, S.E.M.; Parameters of the Modified Soave-Redlich-Kwong Equation of State for Some Chlorofluorocarbons, Hydrofluorocarbons andFluorocarbons, J. Fluorine Chem. 43(1) (1989) 87-104, http://dx.doi.org/10.1016/s0022-1139(00)81638-3

[6]

Valderrama, J.O., De la Puente, H., Ibrahim, A.A.; Generalization of a Polar-Fluid Soave-Redlich-Kwong Equation of State, Fluid Phase Equilibria 93 (1994) 377-383, http://dx.doi.org/10.1016/0378-3812(94)87021-7