def Kweq_1981(T, rho_w):
r'''Calculates equilibrium constant for OH- and H+ in water, according to
[1]_. Second most recent formulation.
.. math::
\log_{10} K_w= A + B/T + C/T^2 + D/T^3 + (E+F/T+G/T^2)\log_{10} \rho_w
Parameters
----------
T : float
Temperature of fluid [K]
rho_w : float
Density of water, [kg/m^3]
Returns
-------
Kweq : float
Ionization constant of water, [-]
Notes
-----
Density is internally converted to units of g/cm^3.
A = -4.098;
B = -3245.2;
C = 2.2362E5;
D = -3.984E7;
E = 13.957;
F = -1262.3;
G = 8.5641E5
Examples
--------
>>> -1*log10(Kweq_1981(600, 700))
11.274522047458206
References
----------
.. [1] Marshall, William L., and E. U. Franck. "Ion Product of Water
Substance, 0-1000 degree C, 1010,000 Bars New International Formulation
and Its Background." Journal of Physical and Chemical Reference Data 10,
no. 2 (April 1, 1981): 295-304. doi:10.1063/1.555643.
'''
rho_w = rho_w / 1000.
A = -4.098
B = -3245.2
C = 2.2362E5
D = -3.984E7
E = 13.957
F = -1262.3
G = 8.5641E5
K_w = 10**(A + B / T + C / T**2 + D / T**3 +
(E + F / T + G / T**2) * log10(rho_w))
return K_w
def Kweq_1981(T, rho_w):
r'''Calculates equilibrium constant for OH- and H+ in water, according to
[1]_. Second most recent formulation.
.. math::
\log_{10} K_w= A + B/T + C/T^2 + D/T^3 + (E+F/T+G/T^2)\log_{10} \rho_w
Parameters
----------
T : float
Temperature of fluid [K]
rho_w : float
Density of water, [kg/m^3]
Returns
-------
Kweq : float
Ionization constant of water, [-]
Notes
-----
Density is internally converted to units of g/cm^3.
A = -4.098;
B = -3245.2;
C = 2.2362E5;
D = -3.984E7;
E = 13.957;
F = -1262.3;
G = 8.5641E5
Examples
--------
>>> -1*log10(Kweq_1981(600, 700))
11.274522047458206
References
----------
.. [1] Marshall, William L., and E. U. Franck. "Ion Product of Water
Substance, 0-1000 degree C, 1010,000 Bars New International Formulation
and Its Background." Journal of Physical and Chemical Reference Data 10,
no. 2 (April 1, 1981): 295-304. doi:10.1063/1.555643.
'''
rho_w = rho_w/1000.
A = -4.098
B = -3245.2
C = 2.2362E5
D = -3.984E7
E = 13.957
F = -1262.3
G = 8.5641E5
return 10**(A + B/T + C/T**2 + D/T**3 + (E + F/T + G/T**2)*log10(rho_w))
def omega(CASRN,
AvailableMethods=False,
Method=None,
IgnoreMethods=['LK', 'DEFINITION']):
r'''This function handles the retrieval of a chemical's acentric factor,
`omega`, or its calculation from correlations or directly through the
definition of acentric factor if possible. Requires a known boiling point,
critical temperature and pressure for use of the correlations. Requires
accurate vapor pressure data for direct calculation.
Will automatically select a method to use if no Method is provided;
returns None if the data is not available and cannot be calculated.
.. math::
\omega \equiv -\log_{10}\left[\lim_{T/T_c=0.7}(P^{sat}/P_c)\right]-1.0
Examples
--------
>>> omega(CASRN='64-17-5')
0.635
Parameters
----------
CASRN : string
CASRN [-]
Returns
-------
omega : float
Acentric factor of compound
methods : list, only returned if AvailableMethods == True
List of methods which can be used to obtain omega with the given inputs
Other Parameters
----------------
Method : string, optional
The method name to use. Accepted methods are 'PSRK', 'PD', 'YAWS',
'LK', and 'DEFINITION'. All valid values are also held in the list
omega_methods.
AvailableMethods : bool, optional
If True, function will determine which methods can be used to obtain
omega for the desired chemical, and will return methods instead of
omega
IgnoreMethods : list, optional
A list of methods to ignore in obtaining the full list of methods,
useful for for performance reasons and ignoring inaccurate methods
Notes
-----
A total of five sources are available for this function. They are:
* 'PSRK', a compillation of experimental and estimated data published
in the Appendix of [15]_, the fourth revision of the PSRK model.
* 'PD', an older compillation of
data published in (Passut & Danner, 1973) [16]_.
* 'YAWS', a large compillation of data from a
variety of sources; no data points are sourced in the work of [17]_.
* 'LK', a estimation method for hydrocarbons.
* 'DEFINITION', based on the definition of omega as
presented in [1]_, using vapor pressure data.
References
----------
.. [1] Pitzer, K. S., D. Z. Lippmann, R. F. Curl, C. M. Huggins, and
D. E. Petersen: The Volumetric and Thermodynamic Properties of Fluids.
II. Compressibility Factor, Vapor Pressure and Entropy of Vaporization.
J. Am. Chem. Soc., 77: 3433 (1955).
.. [2] Horstmann, Sven, Anna Jabłoniec, Jörg Krafczyk, Kai Fischer, and
Jürgen Gmehling. "PSRK Group Contribution Equation of State:
Comprehensive Revision and Extension IV, Including Critical Constants
and Α-Function Parameters for 1000 Components." Fluid Phase Equilibria
227, no. 2 (January 25, 2005): 157-64. doi:10.1016/j.fluid.2004.11.002.
.. [3] Passut, Charles A., and Ronald P. Danner. "Acentric Factor. A
Valuable Correlating Parameter for the Properties of Hydrocarbons."
Industrial & Engineering Chemistry Process Design and Development 12,
no. 3 (July 1, 1973): 365-68. doi:10.1021/i260047a026.
.. [4] Yaws, Carl L. Thermophysical Properties of Chemicals and
Hydrocarbons, Second Edition. Amsterdam Boston: Gulf Professional
Publishing, 2014.
'''
def list_methods():
''' List methods available for calculating a chemical's acentric
factor, omega '''
methods = []
if (CASRN in _crit_PSRKR4.index
and not np.isnan(_crit_PSRKR4.at[CASRN, 'omega'])):
methods.append('PSRK')
if (CASRN in _crit_PassutDanner.index
and not np.isnan(_crit_PassutDanner.at[CASRN, 'omega'])):
methods.append('PD')
if (CASRN in _crit_Yaws.index
and not np.isnan(_crit_Yaws.at[CASRN, 'omega'])):
methods.append('YAWS')
Tcrit, Pcrit = Tc(CASRN), Pc(CASRN)
if Tcrit and Pcrit:
if Tb(CASRN):
methods.append('LK')
if VaporPressure(CASRN=CASRN).T_dependent_property(Tcrit * 0.7):
# TODO: better integration
methods.append('DEFINITION')
if IgnoreMethods:
for Method in IgnoreMethods:
if Method in methods:
methods.remove(Method)
methods.append('NONE')
return methods
if AvailableMethods:
return list_methods()
if not Method:
Method = list_methods()[0]
# This is the calculate, given the method section
if Method == 'PSRK':
_omega = float(_crit_PSRKR4.at[CASRN, 'omega'])
elif Method == 'PD':
_omega = float(_crit_PassutDanner.at[CASRN, 'omega'])
elif Method == 'YAWS':
_omega = float(_crit_Yaws.at[CASRN, 'omega'])
elif Method == 'LK':
_omega = LK_omega(Tb(CASRN), Tc(CASRN), Pc(CASRN))
elif Method == 'DEFINITION':
P = VaporPressure(CASRN=CASRN).T_dependent_property(Tc(CASRN) * 0.7)
_omega = -log10(P / Pc(CASRN)) - 1.0
elif Method == 'NONE':
_omega = None
else:
raise Exception('Failure in in function')
return _omega
def StielPolar(Tc=None,
Pc=None,
omega=None,
CASRN='',
Method=None,
AvailableMethods=False):
r'''This function handles the calculation of a chemical's Stiel Polar
factor, directly through the definition of Stiel-polar factor if possible.
Requires Tc, Pc, acentric factor, and a vapor pressure datum at Tr=0.6.
Will automatically select a method to use if no Method is provided;
returns None if the data is not available and cannot be calculated.
.. math::
x = \log P_r|_{T_r=0.6} + 1.70 \omega + 1.552
Parameters
----------
Tc : float
Critical temperature of fluid [K]
Pc : float
Critical pressure of fluid [Pa]
omega : float
Acentric factor of the fluid [-]
CASRN : string
CASRN [-]
Returns
-------
factor : float
Stiel polar factor of compound
methods : list, only returned if AvailableMethods == True
List of methods which can be used to obtain Stiel polar factor with the
given inputs
Other Parameters
----------------
Method : string, optional
The method name to use. Only 'DEFINITION' is accepted so far.
All valid values are also held in the list Stiel_polar_methods.
AvailableMethods : bool, optional
If True, function will determine which methods can be used to obtain
Stiel-polar factor for the desired chemical, and will return methods
instead of stiel-polar factor
Notes
-----
Only one source is available for this function. It is:
* 'DEFINITION', based on the definition of
Stiel Polar Factor presented in [1]_, using vapor pressure data.
A few points have also been published in [2]_, which may be used for
comparison. Currently this is only used for a surface tension correlation.
Examples
--------
>>> StielPolar(647.3, 22048321.0, 0.344, CASRN='7732-18-5')
0.024581140348734376
References
----------
.. [1] Halm, Roland L., and Leonard I. Stiel. "A Fourth Parameter for the
Vapor Pressure and Entropy of Vaporization of Polar Fluids." AIChE
Journal 13, no. 2 (1967): 351-355. doi:10.1002/aic.690130228.
.. [2] D, Kukoljac Miloš, and Grozdanić Dušan K. "New Values of the
Polarity Factor." Journal of the Serbian Chemical Society 65, no. 12
(January 1, 2000).
http://www.shd.org.rs/JSCS/Vol65/No12-Pdf/JSCS12-07.pdf
'''
def list_methods():
''' List methods available for Stiel's polar factor '''
methods = []
if Tc and Pc and omega:
methods.append('DEFINITION')
methods.append('NONE')
return methods
if AvailableMethods:
return list_methods()
if not Method:
Method = list_methods()[0]
if Method == 'DEFINITION':
P = VaporPressure(CASRN=CASRN).T_dependent_property(Tc * 0.6)
if not P:
factor = None
else:
Pr = P / Pc
factor = log10(Pr) + 1.70 * omega + 1.552
elif Method == 'NONE':
factor = None
else:
raise Exception('Failure in in function')
return factor
def Kweq_IAPWS(T, rho_w):
r'''Calculates equilibrium constant for OH- and H+ in water, according to
[1]_.
This is the most recent formulation available.
.. math::
Q = \rho \exp(\alpha_0 + \alpha_1 T^{-1} + \alpha_2 T^{-2} \rho^{2/3})
- \log_{10} K_w = -2n \left[ \log_{10}(1+Q) - \frac{Q}{Q+1} \rho
(\beta_0 + \beta_1 T^{-1} + \beta_2 \rho) \right]
-\log_{10} K_w^G + 2 \log_{10} \frac{18.015268}{1000}
Parameters
----------
T : float
Temperature of water [K]
rho_w : float
Density of water at temperature and pressure [kg/m^3]
Returns
-------
Kweq : float
Ionization constant of water, [-]
Notes
-----
Formulation is in terms of density in g/cm^3; density
is converted internally.
n = 6;
alpha0 = -0.864671;
alpha1 = 8659.19;
alpha2 = -22786.2;
beta0 = 0.642044;
beta1 = -56.8534;
beta2 = -0.375754
Examples
--------
Example from IAPWS check:
>>> -1*log10(Kweq_IAPWS(600, 700))
11.203153057603775
References
----------
.. [1] Bandura, Andrei V., and Serguei N. Lvov. "The Ionization Constant
of Water over Wide Ranges of Temperature and Density." Journal of Physical
and Chemical Reference Data 35, no. 1 (March 1, 2006): 15-30.
doi:10.1063/1.1928231
'''
K_w_G = Kweq_IAPWS_gas(T)
rho_w = rho_w / 1000.
n = 6
alpha0 = -0.864671
alpha1 = 8659.19
alpha2 = -22786.2
beta0 = 0.642044
beta1 = -56.8534
beta2 = -0.375754
Q = rho_w * exp(alpha0 + alpha1 / T + alpha2 / T**2 * rho_w**(2 / 3.))
K_w = 10**(-1 * (-2 * n * (log10(1 + Q) - Q / (Q + 1) * rho_w *
(beta0 + beta1 / T + beta2 * rho_w)) -
log10(K_w_G) + 2 * log10(18.015268 / 1000)))
return K_w
def Kweq_IAPWS(T, rho_w):
r'''Calculates equilibrium constant for OH- and H+ in water, according to
[1]_.
This is the most recent formulation available.
.. math::
Q = \rho \exp(\alpha_0 + \alpha_1 T^{-1} + \alpha_2 T^{-2} \rho^{2/3})
- \log_{10} K_w = -2n \left[ \log_{10}(1+Q) - \frac{Q}{Q+1} \rho
(\beta_0 + \beta_1 T^{-1} + \beta_2 \rho) \right]
-\log_{10} K_w^G + 2 \log_{10} \frac{18.015268}{1000}
Parameters
----------
T : float
Temperature of water [K]
rho_w : float
Density of water at temperature and pressure [kg/m^3]
Returns
-------
Kweq : float
Ionization constant of water, [-]
Notes
-----
Formulation is in terms of density in g/cm^3; density
is converted internally.
n = 6;
alpha0 = -0.864671;
alpha1 = 8659.19;
alpha2 = -22786.2;
beta0 = 0.642044;
beta1 = -56.8534;
beta2 = -0.375754
Examples
--------
Example from IAPWS check:
>>> -1*log10(Kweq_IAPWS(600, 700))
11.203153057603775
References
----------
.. [1] Bandura, Andrei V., and Serguei N. Lvov. "The Ionization Constant
of Water over Wide Ranges of Temperature and Density." Journal of Physical
and Chemical Reference Data 35, no. 1 (March 1, 2006): 15-30.
doi:10.1063/1.1928231
'''
K_w_G = Kweq_IAPWS_gas(T)
rho_w = rho_w/1000.
n = 6
alpha0 = -0.864671
alpha1 = 8659.19
alpha2 = -22786.2
beta0 = 0.642044
beta1 = -56.8534
beta2 = -0.375754
Q = rho_w*exp(alpha0 + alpha1/T + alpha2/T**2*rho_w**(2/3.))
K_w = 10**(-1*(-2*n*(log10(1+Q)-Q/(Q+1) * rho_w *(beta0 + beta1/T + beta2*rho_w)) -
log10(K_w_G) + 2*log10(18.015268/1000) ))
return K_w
def omega(CASRN, AvailableMethods=False, Method=None, IgnoreMethods=['LK', 'DEFINITION']):
r'''This function handles the retrieval of a chemical's acentric factor,
`omega`, or its calculation from correlations or directly through the
definition of acentric factor if possible. Requires a known boiling point,
critical temperature and pressure for use of the correlations. Requires
accurate vapor pressure data for direct calculation.
Will automatically select a method to use if no Method is provided;
returns None if the data is not available and cannot be calculated.
.. math::
\omega \equiv -\log_{10}\left[\lim_{T/T_c=0.7}(P^{sat}/P_c)\right]-1.0
Examples
--------
>>> omega(CASRN='64-17-5')
0.635
Parameters
----------
CASRN : string
CASRN [-]
Returns
-------
omega : float
Acentric factor of compound
methods : list, only returned if AvailableMethods == True
List of methods which can be used to obtain omega with the given inputs
Other Parameters
----------------
Method : string, optional
The method name to use. Accepted methods are 'PSRK', 'PD', 'YAWS',
'LK', and 'DEFINITION'. All valid values are also held in the list
omega_methods.
AvailableMethods : bool, optional
If True, function will determine which methods can be used to obtain
omega for the desired chemical, and will return methods instead of
omega
IgnoreMethods : list, optional
A list of methods to ignore in obtaining the full list of methods,
useful for for performance reasons and ignoring inaccurate methods
Notes
-----
A total of five sources are available for this function. They are:
* 'PSRK', a compillation of experimental and estimated data published
in the Appendix of [15]_, the fourth revision of the PSRK model.
* 'PD', an older compillation of
data published in (Passut & Danner, 1973) [16]_.
* 'YAWS', a large compillation of data from a
variety of sources; no data points are sourced in the work of [17]_.
* 'LK', a estimation method for hydrocarbons.
* 'DEFINITION', based on the definition of omega as
presented in [1]_, using vapor pressure data.
References
----------
.. [1] Pitzer, K. S., D. Z. Lippmann, R. F. Curl, C. M. Huggins, and
D. E. Petersen: The Volumetric and Thermodynamic Properties of Fluids.
II. Compressibility Factor, Vapor Pressure and Entropy of Vaporization.
J. Am. Chem. Soc., 77: 3433 (1955).
.. [2] Horstmann, Sven, Anna Jabłoniec, Jörg Krafczyk, Kai Fischer, and
Jürgen Gmehling. "PSRK Group Contribution Equation of State:
Comprehensive Revision and Extension IV, Including Critical Constants
and Α-Function Parameters for 1000 Components." Fluid Phase Equilibria
227, no. 2 (January 25, 2005): 157-64. doi:10.1016/j.fluid.2004.11.002.
.. [3] Passut, Charles A., and Ronald P. Danner. "Acentric Factor. A
Valuable Correlating Parameter for the Properties of Hydrocarbons."
Industrial & Engineering Chemistry Process Design and Development 12,
no. 3 (July 1, 1973): 365-68. doi:10.1021/i260047a026.
.. [4] Yaws, Carl L. Thermophysical Properties of Chemicals and
Hydrocarbons, Second Edition. Amsterdam Boston: Gulf Professional
Publishing, 2014.
'''
def list_methods():
methods = []
if CASRN in _crit_PSRKR4.index and not np.isnan(_crit_PSRKR4.at[CASRN, 'omega']):
methods.append('PSRK')
if CASRN in _crit_PassutDanner.index and not np.isnan(_crit_PassutDanner.at[CASRN, 'omega']):
methods.append('PD')
if CASRN in _crit_Yaws.index and not np.isnan(_crit_Yaws.at[CASRN, 'omega']):
methods.append('YAWS')
Tcrit, Pcrit = Tc(CASRN), Pc(CASRN)
if Tcrit and Pcrit:
if Tb(CASRN):
methods.append('LK')
if VaporPressure(CASRN=CASRN).T_dependent_property(Tcrit*0.7):
methods.append('DEFINITION') # TODO: better integration
if IgnoreMethods:
for Method in IgnoreMethods:
if Method in methods:
methods.remove(Method)
methods.append('NONE')
return methods
if AvailableMethods:
return list_methods()
if not Method:
Method = list_methods()[0]
# This is the calculate, given the method section
if Method == 'PSRK':
_omega = float(_crit_PSRKR4.at[CASRN, 'omega'])
elif Method == 'PD':
_omega = float(_crit_PassutDanner.at[CASRN, 'omega'])
elif Method == 'YAWS':
_omega = float(_crit_Yaws.at[CASRN, 'omega'])
elif Method == 'LK':
_omega = LK_omega(Tb(CASRN), Tc(CASRN), Pc(CASRN))
elif Method == 'DEFINITION':
P = VaporPressure(CASRN=CASRN).T_dependent_property(Tc(CASRN)*0.7)
_omega = -log10(P/Pc(CASRN)) - 1.0
elif Method == 'NONE':
_omega = None
else:
raise Exception('Failure in in function')
return _omega
def StielPolar(Tc=None, Pc=None, omega=None, CASRN='', Method=None,
AvailableMethods=False):
r'''This function handles the calculation of a chemical's Stiel Polar
factor, directly through the definition of Stiel-polar factor if possible.
Requires Tc, Pc, acentric factor, and a vapor pressure datum at Tr=0.6.
Will automatically select a method to use if no Method is provided;
returns None if the data is not available and cannot be calculated.
.. math::
x = \log P_r|_{T_r=0.6} + 1.70 \omega + 1.552
Parameters
----------
Tc : float
Critical temperature of fluid [K]
Pc : float
Critical pressure of fluid [Pa]
omega : float
Acentric factor of the fluid [-]
CASRN : string
CASRN [-]
Returns
-------
factor : float
Stiel polar factor of compound
methods : list, only returned if AvailableMethods == True
List of methods which can be used to obtain Stiel polar factor with the
given inputs
Other Parameters
----------------
Method : string, optional
The method name to use. Only 'DEFINITION' is accepted so far.
All valid values are also held in the list Stiel_polar_methods.
AvailableMethods : bool, optional
If True, function will determine which methods can be used to obtain
Stiel-polar factor for the desired chemical, and will return methods
instead of stiel-polar factor
Notes
-----
Only one source is available for this function. It is:
* 'DEFINITION', based on the definition of
Stiel Polar Factor presented in [1]_, using vapor pressure data.
A few points have also been published in [2]_, which may be used for
comparison. Currently this is only used for a surface tension correlation.
Examples
--------
>>> StielPolar(647.3, 22048321.0, 0.344, CASRN='7732-18-5')
0.024581140348734376
References
----------
.. [1] Halm, Roland L., and Leonard I. Stiel. "A Fourth Parameter for the
Vapor Pressure and Entropy of Vaporization of Polar Fluids." AIChE
Journal 13, no. 2 (1967): 351-355. doi:10.1002/aic.690130228.
.. [2] D, Kukoljac Miloš, and Grozdanić Dušan K. "New Values of the
Polarity Factor." Journal of the Serbian Chemical Society 65, no. 12
(January 1, 2000). http://www.shd.org.rs/JSCS/Vol65/No12-Pdf/JSCS12-07.pdf
'''
def list_methods():
methods = []
if Tc and Pc and omega:
methods.append('DEFINITION')
methods.append('NONE')
return methods
if AvailableMethods:
return list_methods()
if not Method:
Method = list_methods()[0]
if Method == 'DEFINITION':
P = VaporPressure(CASRN=CASRN).T_dependent_property(Tc*0.6)
if not P:
factor = None
else:
Pr = P/Pc
factor = log10(Pr) + 1.70*omega + 1.552
elif Method == 'NONE':
factor = None
else:
raise Exception('Failure in in function')
return factor
