critical¶
All data and methods related to the estimation of a chemical’s critical properties.
References
- 1(1,2,3)
Ambrose, Douglas, and Colin L. Young. “Vapor-Liquid Critical Properties of Elements and Compounds. 1. An Introductory Survey.” Journal of Chemical & Engineering Data 41, no. 1 (January 1, 1996): 154-154. doi:10.1021/je950378q.
- 2(1,2,3)
Ambrose, Douglas, and Constantine Tsonopoulos. “Vapor-Liquid Critical Properties of Elements and Compounds. 2. Normal Alkanes.” Journal of Chemical & Engineering Data 40, no. 3 (May 1, 1995): 531-46. doi:10.1021/je00019a001.
- 3(1,2,3)
Tsonopoulos, Constantine, and Douglas Ambrose. “Vapor-Liquid Critical Properties of Elements and Compounds. 3. Aromatic Hydrocarbons.” Journal of Chemical & Engineering Data 40, no. 3 (May 1, 1995): 547-58. doi:10.1021/je00019a002.
- 4(1,2,3)
Gude, Michael, and Amyn S. Teja. “Vapor-Liquid Critical Properties of Elements and Compounds. 4. Aliphatic Alkanols.” Journal of Chemical & Engineering Data 40, no. 5 (September 1, 1995): 1025-36. doi:10.1021/je00021a001.
- 5(1,2,3)
Daubert, Thomas E. “Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes.” Journal of Chemical & Engineering Data 41, no. 3 (January 1, 1996): 365-72. doi:10.1021/je9501548.
- 6(1,2,3)
Tsonopoulos, Constantine, and Douglas Ambrose. “Vapor-Liquid Critical Properties of Elements and Compounds. 6. Unsaturated Aliphatic Hydrocarbons.” Journal of Chemical & Engineering Data 41, no. 4 (January 1, 1996): 645-56. doi:10.1021/je9501999.
- 7(1,2,3)
Kudchadker, Arvind P., Douglas Ambrose, and Constantine Tsonopoulos. “Vapor-Liquid Critical Properties of Elements and Compounds. 7. Oxygen Compounds Other Than Alkanols and Cycloalkanols.” Journal of Chemical & Engineering Data 46, no. 3 (May 1, 2001): 457-79. doi:10.1021/je0001680.
- 8(1,2,3)
Tsonopoulos, Constantine, and Douglas Ambrose. “Vapor-Liquid Critical Properties of Elements and Compounds. 8. Organic Sulfur, Silicon, and Tin Compounds (C + H + S, Si, and Sn).” Journal of Chemical & Engineering Data 46, no. 3 (May 1, 2001): 480-85. doi:10.1021/je000210r.
- 9(1,2,3)
Marsh, Kenneth N., Colin L. Young, David W. Morton, Douglas Ambrose, and Constantine Tsonopoulos. “Vapor-Liquid Critical Properties of Elements and Compounds. 9. Organic Compounds Containing Nitrogen.” Journal of Chemical & Engineering Data 51, no. 2 (March 1, 2006): 305-14. doi:10.1021/je050221q.
- 10(1,2,3)
Marsh, Kenneth N., Alan Abramson, Douglas Ambrose, David W. Morton, Eugene Nikitin, Constantine Tsonopoulos, and Colin L. Young. “Vapor-Liquid Critical Properties of Elements and Compounds. 10. Organic Compounds Containing Halogens.” Journal of Chemical & Engineering Data 52, no. 5 (September 1, 2007): 1509-38. doi:10.1021/je700336g.
- 11(1,2,3)
Ambrose, Douglas, Constantine Tsonopoulos, and Eugene D. Nikitin. “Vapor-Liquid Critical Properties of Elements and Compounds. 11. Organic Compounds Containing B + O; Halogens + N, + O, + O + S, + S, + Si; N + O; and O + S, + Si.” Journal of Chemical & Engineering Data 54, no. 3 (March 12, 2009): 669-89. doi:10.1021/je800580z.
- 12(1,2,3)
Ambrose, Douglas, Constantine Tsonopoulos, Eugene D. Nikitin, David W. Morton, and Kenneth N. Marsh. “Vapor-Liquid Critical Properties of Elements and Compounds. 12. Review of Recent Data for Hydrocarbons and Non-Hydrocarbons.” Journal of Chemical & Engineering Data, October 5, 2015, 151005081500002. doi:10.1021/acs.jced.5b00571.
- 13(1,2,3)
Mathews, Joseph F. “Critical Constants of Inorganic Substances.” Chemical Reviews 72, no. 1 (February 1, 1972): 71-100. doi:10.1021/cr60275a004.
- 14(1,2,3)
Haynes, W.M., Thomas J. Bruno, and David R. Lide. CRC Handbook of Chemistry and Physics, 95E. Boca Raton, FL: CRC press, 2014.
- 15(1,2,3)
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.
- 16(1,2,3)
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.
- 17(1,2,3)
Yaws, Carl L. Thermophysical Properties of Chemicals and Hydrocarbons, Second Edition. Amsterdam Boston: Gulf Professional Publishing, 2014.
- 18
Mersmann, Alfons, and Matthias Kind. “Correlation for the Prediction of Critical Molar Volume.” Industrial & Engineering Chemistry Research, October 16, 2017. https://doi.org/10.1021/acs.iecr.7b03171.
- 19
Mersmann, Alfons, and Matthias Kind. “Prediction of Mechanical and Thermal Properties of Pure Liquids, of Critical Data, and of Vapor Pressure.” Industrial & Engineering Chemistry Research, January 31, 2017. https://doi.org/10.1021/acs.iecr.6b04323.
- 20
Ihmels, E. Christian. “The Critical Surface.” Journal of Chemical & Engineering Data 55, no. 9 (September 9, 2010): 3474-80. doi:10.1021/je100167w.
- 21
Meissner, H. P., and E. M. Redding. “Prediction of Critical Constants.” Industrial & Engineering Chemistry 34, no. 5 (May 1, 1942): 521-26. doi:10.1021/ie50389a003.
- 22
Grigoras, Stelian. “A Structural Approach to Calculate Physical Properties of Pure Organic Substances: The Critical Temperature, Critical Volume and Related Properties.” Journal of Computational Chemistry 11, no. 4 (May 1, 1990): 493-510. doi:10.1002/jcc.540110408
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thermosteam.properties.critical.
critical_point_temperature
(CASRN, method='Any')[source]¶ This function handles the retrieval of a chemical’s critical temperature. Lookup is based on CASRNs. Will automatically select a data source to use if no Method is provided; returns None if the data is not available.
Prefered sources are ‘IUPAC’ for organic chemicals, and ‘Matthews’ for inorganic chemicals. Function has data for approximately 1000 chemicals.
- Parameters
CASRN (string) – CASRN [-]
- Returns
Tc – Critical temperature, [K]
- Return type
float
- Other Parameters
method (string, optional) – The method name to use. Accepted methods are ‘IUPAC’, ‘Matthews’, ‘CRC’, ‘PSRK’, ‘Passut Danner’, and ‘Yaws’. If method is “Any”, the first available value from these methods will returned. If method is “All”, a dictionary of method results will be returned.
Notes
A total of six sources are available for this function. They are:
‘IUPAC Organic Critical Properties’, a series of critically evaluated experimental datum for organic compounds in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.
‘Matthews Inorganic Critical Properties’, a series of critically evaluated data for inorganic compounds in 13.
‘CRC Organic Critical Properties’, a compillation of critically evaluated data by the TRC as published in 14.
‘PSRK Revision 4 Appendix’, a compillation of experimental and estimated data published in 15.
‘Passut Danner 1973 Critical Properties’, an older compillation of data published in 16
‘Yaws Critical Properties’, a large compillation of data from a variety of sources; no data points are sourced in the work of 17.
Examples
>>> critical_point_temperature(CASRN='64-17-5') 514.0
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thermosteam.properties.critical.
critical_point_pressure
(CASRN, method='Any')[source]¶ Retrieve the critical pressure of a chemical. Lookup is based on CASRNs. Automatically select a data source to use if no Method is provided. Return None if the data is not available.
Prefered sources are ‘IUPAC’ for organic chemicals, and ‘Matthews’ for inorganic chemicals. Function has data for approximately 1000 chemicals.
Examples
>>> critical_point_pressure(CASRN='64-17-5') 6137000.0
- Parameters
CASRN (string) – CASRN [-]
- Returns
Pc – Critical pressure, [Pa]
- Return type
float
- Other Parameters
method (string, optional) – The method name to use. Accepted methods are ‘IUPAC’, ‘Matthews’, ‘CRC’, ‘PSRK’, ‘Passut Danner’, and ‘Yaws’. If method is “Any”, the first available value from these methods will returned. If method is “All”, a dictionary of method results will be returned.
Notes
A total of six sources are available for this function. They are:
‘IUPAC Organic Critical Properties’, a series of critically evaluated experimental datum for organic compounds in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.
‘Matthews Inorganic Critical Properties’, a series of critically evaluated data for inorganic compounds in 13.
‘CRC Organic Critical Properties’, a compillation of critically evaluated data by the TRC as published in 14.
‘PSRK Revision 4 Appendix’, a compillation of experimental and estimated data published in 15.
‘Passut Danner 1973 Critical Properties’, an older compillation of data published in 16
‘Yaws Critical Properties’, a large compillation of data from a variety of sources; no data points are sourced in the work of 17.
-
thermosteam.properties.critical.
critical_point_volume
(CASRN, method='Any')[source]¶ Retrieve the critical volume of a chemical. Lookup is based on CASRNs. Automatically select a data source to use if no Method is provided; return None if the data is not available.
Prefered sources are ‘IUPAC’ for organic chemicals, and ‘Matthews’ for inorganic chemicals. Function has data for approximately 1000 chemicals.
Examples
>>> critical_point_volume(CASRN='64-17-5') 0.000168
- Parameters
CASRN (string) – CASRN [-]
- Returns
Vc – Critical volume, [m^3/mol]
- Return type
float
- Other Parameters
method (string, optional) – The method name to use. Accepted methods are ‘IUPAC’, ‘Matthews’, ‘CRC’, ‘PSRK’, ‘Passut Danner’, and ‘Yaws’. If method is “Any”, the first available value from these methods will returned. If method is “All”, a dictionary of method results will be returned.
Notes
A total of six sources are available for this function. They are:
‘IUPAC Organic Critical Properties’, a series of critically evaluated experimental datum for organic compounds in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12.
‘Matthews Inorganic Critical Properties’, a series of critically evaluated data for inorganic compounds in 13.
‘CRC Organic Critical Properties’, a compillation of critically evaluated data by the TRC as published in 14.
‘PSRK Revision 4 Appendix’, a compillation of experimental and estimated data published in 15.
‘Passut Danner 1973 Critical Properties’, an older compillation of data published in 16
‘Yaws Critical Properties’, a large compillation of data from a variety of sources; no data points are sourced in the work of 17.
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thermosteam.properties.critical.
Mersmann_Kind_predictor
(atoms, coeff=3.645, power=0.5, covalent_radii={'Br': 1.14, 'C': 0.77, 'Cl': 0.99, 'F': 0.71, 'H': 0.37, 'I': 1.33, 'N': 0.71, 'O': 0.6, 'S': 1.04, 'Si': 1.17})[source]¶ Predicts the critical molar volume of a chemical based only on its atomic composition according to 18 and 19. This is a crude approach, but provides very reasonable estimates in practice. Optionally, the coeff used and the power in the fraction as well as the atomic contributions can be adjusted; this method is general and atomic contributions can be regressed to predict other properties with this routine.
\[ \begin{align}\begin{aligned}\frac{\left(\frac{V_c}{n_a N_A}\right)^{1/3}}{d_a} = \frac{3.645}{\left(\frac{r_a}{r_H}\right)^{1/2}}\\r_a = d_a/2\\d_a = 2 \frac{\sum_i (n_i r_i)}{n_a}\end{aligned}\end{align} \]In the above equations, \(n_i\) is the number of atoms of species i in the molecule, \(r_i\) is the covalent atomic radius of the atom, and \(n_a\) is the total number of atoms in the molecule.
- Parameters
atoms (dict) – Dictionary of atoms and their counts, [-]
coeff (float, optional) – Coefficient used in the relationship, [m^2]
power (float, optional) – Power applied to the relative atomic radius, [-]
covalent_radii (dict or indexable, optional) – Object which can be indexed to atomic contrinbutions (by symbol), [-]
- Returns
Vc – Predicted critical volume of the chemical, [m^3/mol]
- Return type
float
Notes
Using the
thermo.elements.periodic_table
covalent radii (from RDKit), the coefficient and power should be 4.261206523632586 and 0.5597281770786228 respectively for best results.Examples
Prediction of critical volume of decane:
>>> Mersmann_Kind_predictor({'C': 10, 'H': 22}) 0.0005851859052024729
This is compared against the experimental value, 0.000624 (a 6.2% relative error)
Using custom fitted coefficients we can do a bit better:
>>> from thermo.critical import rcovs_regressed >>> Mersmann_Kind_predictor({'C': 10, 'H': 22}, coeff=4.261206523632586, ... power=0.5597281770786228, covalent_radii=rcovs_regressed) 0.0005956871011923075
The relative error is only 4.5% now. This is compared to an experimental uncertainty of 5.6%.
Evaluating 1321 critical volumes in the database, the average relative error is 5.0%; standard deviation 6.8%; and worst value of 79% relative error for phosphorus.
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thermosteam.properties.critical.
Ihmels
(Tc=None, Pc=None, Vc=None)[source]¶ Most recent, and most recommended method of estimating critical properties from each other. Two of the three properties are required. This model uses the “critical surface”, a general plot of Tc vs Pc vs Vc. The model used 421 organic compounds to derive equation. The general equation is in 20:
\[P_c = -0.025 + 2.215 \frac{T_c}{V_c}\]- Parameters
Tc (float, optional) – Critical temperature of fluid [K]
Pc (float, optional) – Critical pressure of fluid [Pa]
Vc (float, optional) – Critical volume of fluid [m^3/mol]
- Returns
critical_point – Critical point of the fluid [K], [Pa], and [m^3/mol]
- Return type
CriticalPoint
Notes
The prediction of Tc from Pc and Vc is not tested, as this is not necessary anywhere, but it is implemented. Internal units are MPa, cm^3/mol, and K. A slight error occurs when Pa, cm^3/mol and K are used instead, on the order of <0.2%. Their equation was also compared with 56 inorganic and elements. Devations of 20% for <200K or >1000K points.
Examples ——–a Succinic acid [110-15-6]
>>> Ihmels(Tc=851.0, Vc=0.000308) 6095016.233766234
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thermosteam.properties.critical.
Meissner
(Tc=None, Pc=None, Vc=None)[source]¶ Old (1942) relationship for estimating critical properties from each other. Two of the three properties are required. This model uses the “critical surface”, a general plot of Tc vs Pc vs Vc. The model used 42 organic and inorganic compounds to derive the equation. The general equation is in 21:
\[P_c = \frac{2.08 T_c}{V_c-8}\]- Parameters
Tc (float, optional) – Critical temperature of fluid [K]
Pc (float, optional) – Critical pressure of fluid [Pa]
Vc (float, optional) – Critical volume of fluid [m^3/mol]
- Returns
critical_point – Critical point of the fluid [K], [Pa], and [m^3/mol]
- Return type
CriticalPoint
Notes
The prediction of Tc from Pc and Vc is not tested, as this is not necessary anywhere, but it is implemented. Internal units are atm, cm^3/mol, and K. A slight error occurs when Pa, cm^3/mol and K are used instead, on the order of <0.2%. This equation is less accurate than that of Ihmels, but surprisingly close. The author also proposed means of estimated properties independently.
Examples
Succinic acid [110-15-6]
>>> Meissner(Tc=851.0, Vc=0.000308) 5978445.199999999
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thermosteam.properties.critical.
Grigoras
(Tc=None, Pc=None, Vc=None)[source]¶ Relatively recent (1990) relationship for estimating critical properties from each other. Two of the three properties are required. This model uses the “critical surface”, a general plot of Tc vs Pc vs Vc. The model used 137 organic and inorganic compounds to derive the equation. The general equation is in 22:
\[P_c = 2.9 + 20.2 \frac{T_c}{V_c}\]- Parameters
Tc (float, optional) – Critical temperature of fluid [K]
Pc (float, optional) – Critical pressure of fluid [Pa]
Vc (float, optional) – Critical volume of fluid [m^3/mol]
- Returns
critical_point – Critical point of the fluid [K], [Pa], and [m^3/mol]
- Return type
CriticalPoint
Notes
The prediction of Tc from Pc and Vc is not tested, as this is not necessary anywhere, but it is implemented. Internal units are bar, cm^3/mol, and K. A slight error occurs when Pa, cm^3/mol and K are used instead, on the order of <0.2%. This equation is less accurate than that of Ihmels, but surprisingly close. The author also investigated an early QSPR model.
Examples
Succinic acid [110-15-6]
>>> Grigoras(Tc=851.0, Vc=0.000308) 5871233.766233766