activity_coefficients#

class ActivityCoefficients[source]#

Abstract class for the estimation of activity coefficients. Non-abstract subclasses should implement the following methods:

__init__(self, chemicals: Iterable[Chemical]):: Should use pure component data from chemicals to setup future calculations of activity coefficients.
__call__(self, x: 1d array, T: float):: Should accept an array of liquid molar compositions x, and temperature T (in Kelvin), and return an array of activity coefficients. Note that the molar compositions must be in the same order as the chemicals defined when creating the ActivityCoefficients object.

property chemicals#: tuple[Chemical] All chemicals involved in the calculation of activity coefficients.

class IdealActivityCoefficients(chemicals)[source]#

Create an IdealActivityCoefficients object that estimates all activity coefficients to be 1 when called with a composition and a temperature (K).

Parameters:: chemicals (Iterable[Chemical])

__call__(xs, T)[source]#: Call self as a function.

class GroupActivityCoefficients(chemicals)[source]#

Abstract class for the estimation of activity coefficients using group contribution methods.

Parameters:: chemicals (Iterable[Chemical])

activity_coefficients(x, T)[source]#

Return activity coefficients of chemicals with defined functional groups.

Parameters:

x (array_like) – Molar fractions
T (float) – Temperature [K]

__call__(x, T)[source]#

Return activity coefficients.

Parameters:

x (array_like) – Molar fractions
T (float) – Temperature [K]

Notes

Activity coefficients of chemicals with missing groups are default to 1.

class DortmundActivityCoefficients(chemicals)[source]#

Create a DortmundActivityCoefficients that estimates activity coefficients using the Dortmund UNIFAC group contribution method when called with a composition and a temperature (K).

Parameters:: chemicals (Iterable[Chemical])

Examples

>>> import thermosteam as tmo
>>> chemicals = tmo.Chemicals(['Water', 'Ethanol'], cache=True)
>>> Gamma = tmo.equilibrium.DortmundActivityCoefficients(chemicals)
>>> composition = [0.5, 0.5]
>>> T = 350.
>>> Gamma(composition, T)
array([1.475, 1.242])

>>> chemicals = tmo.Chemicals(['Dodecane', 'Tridecane'], cache=True)
>>> Gamma = tmo.equilibrium.DortmundActivityCoefficients(chemicals)
>>> # Note how both hydrocarbons have similar lenghts and structure,
>>> # so activities should be very close
>>> Gamma([0.5, 0.5], 350.)
array([1., 1.])

>>> chemicals = tmo.Chemicals(['Water', 'O2'], cache=True)
>>> Gamma = tmo.equilibrium.DortmundActivityCoefficients(chemicals)
>>> # The following warning is issued because O2 does not have Dortmund groups
>>> # RuntimeWarning: O2 has no defined Dortmund groups;
>>> # functional group interactions are ignored
>>> Gamma([0.5, 0.5], 350.)
array([1., 1.])

class UNIFACActivityCoefficients(chemicals)[source]#

Create a UNIFACActivityCoefficients that estimates activity coefficients using the UNIFAC group contribution method when called with a composition and a temperature (K).

Parameters:: chemicals (Iterable[Chemical])

class NISTActivityCoefficients(chemicals)[source]#

Create a NISTActivityCoefficients that estimates activity coefficients using the NIST-modified UNIFAC group contribution method when called with a composition and a temperature (K).

Parameters:: chemicals (Iterable[Chemical])

Examples

>>> import thermosteam as tmo
>>> Water, Ethanol = chemicals = tmo.Chemicals(['Water', 'Ethanol'], cache=True)
>>> Ethanol.NIST.set_group_counts_by_name({'CH3':1, 'CH2':1, 'OH prim':1})
>>> Water.NIST.set_group_counts_by_name({'H2O':1})
>>> Gamma = tmo.equilibrium.NISTActivityCoefficients(chemicals)
>>> composition = [0.5, 0.5]
>>> T = 350.
>>> Gamma(composition, T)
array([1.479, 1.238])

class PRActivityCoefficients(chemicals)#

EOS#: alias of PRMIX

class SRKActivityCoefficients(chemicals)#

EOS#: alias of SRKMIX

class PR78ActivityCoefficients(chemicals)#

EOS#: alias of PR78MIX

class VDWActivityCoefficients(chemicals)#

EOS#: alias of VDWMIX

class PRSVActivityCoefficients(chemicals)#

EOS#: alias of PRSVMIX

class PRSV2ActivityCoefficients(chemicals)#

EOS#: alias of PRSV2MIX

class TWUPRActivityCoefficients(chemicals)#

EOS#: alias of TWUPRMIX

class TWUSRKActivityCoefficients(chemicals)#

EOS#: alias of TWUSRKMIX

class APISRKActivityCoefficients(chemicals)#

EOS#: alias of APISRKMIX

class IGActivityCoefficients(chemicals)#

EOS#: alias of IGMIX

class RKActivityCoefficients(chemicals)#

EOS#: alias of RKMIX

class PRMIXTranslatedConsistActivityCoefficients(chemicals)#

EOS#: alias of PRMIXTranslatedConsistent

class PRMIXTranslatedPActivityCoefficients(chemicals)#

EOS#: alias of PRMIXTranslatedPPJP

class PRMIXTranslaActivityCoefficients(chemicals)#

EOS#: alias of PRMIXTranslated

class SRKMIXTranslatedConsistActivityCoefficients(chemicals)#

EOS#: alias of SRKMIXTranslatedConsistent

class PActivityCoefficients(chemicals)#

EOS#: alias of PSRK

class MSRKMIXTranslaActivityCoefficients(chemicals)#

EOS#: alias of MSRKMIXTranslated

class SRKMIXTranslaActivityCoefficients(chemicals)#

EOS#: alias of SRKMIXTranslated