n-Heptane

References

Equation of State

R. Span and W. Wagner. Equations of State for Technical Applications. II. Results for Nonpolar Fluids. Int. J. Thermophys., 24:41–109, 2003. doi:10.1023/A:1022310214958.

Ideal gas specific heat

M. Jaeschke and P. Schley. Ideal-Gas Thermodynamic Properties for Natural-Gas Applications. Int. J. Thermophys., 16(6):1381–1392, 1995. doi:10.1007/BF02083547.

Thermal Conductivity

M. J. Assael, I. Bogdanou, S. K. Mylona, M. L. Huber, R. A. Perkins, and V. Vesovic. Reference Correlation of the Thermal Conductivity of n-Heptane from the Triple Point to 600 K and up to 250 MPa. J. Phys. Chem. Ref. Data, 42(2):023101–1:9, 2013. doi:10.1063/1.4794091.

Viscosity

E. K. Michailidou, M. J. Assael, M. L. Huber, I. M. Abdulagatov, and R. A. Perkins. Reference Correlation of the Viscosity of n-Heptane from the Triple Point to 600 K and up to 248 MPa. J. Phys. Chem. Ref. Data, 43:023103, 2014. doi:10.1063/1.4875930.

Surface Tension

A. Mulero, I. Cachadiña, and M. I. Parra. Recommended Correlations for the Surface Tension of Common Fluids. J. Phys. Chem. Ref. Data, 41(4):043105–1:13, 2012. doi:10.1063/1.4768782.

Aliases

nHeptane, Heptane, HEPTANE, N-HEPTANE, NC7H16, n-C7H16

Molecular Structure

n-Heptane — 3D conformer (interactive: click and drag to rotate)

Fluid Information

Parameter, Value
General
Molar mass [kg/mol]	0.100202
CAS number	142-82-5
ASHRAE class	UNKNOWN
Formula	C7H16
Acentric factor	0.349
InChI	InChI=1S/C7H16/c1-3-5-7-6-4-2/h3-7H2,1-2H3
InChIKey	IMNFDUFMRHMDMM-UHFFFAOYSA-N
SMILES	CCCCCCC
ChemSpider ID	8560
Limits
Maximum temperature [K]	600.0
Maximum pressure [Pa]	100000000.0
Triple point
Triple point temperature [K]	182.55
Triple point pressure [Pa]	0.17549028983207446
Critical point
Critical point temperature [K]	541.2259150893126
Critical point density [kg/m3]	224.90140970218573
Critical point density [mol/m3]	2244.4802469230726
Critical point pressure [Pa]	2773824.280294774
Reducing point
Reducing point temperature [K]	540.13
Reducing point density [mol/m3]	2315.323047444163

REFPROP Validation Data

Note

This figure compares the results generated from CoolProp and those generated from REFPROP. They are all results obtained in the form \(Y(T,\rho)\), where \(Y\) is the parameter of interest and which for all EOS is a direct evaluation of the EOS

You can download the script that generated the following figure here: (link to script), right-click the link and then save as… or the equivalent in your browser. You can also download this figure as a PDF.

Consistency Plots

The following figure shows all the flash routines that are available for this fluid. A red + is a failure of the flash routine, a black dot is a success. Hopefully you will only see black dots. The red curve is the maximum temperature curve, and the blue curve is the melting line if one is available for the fluid.

In this figure, we start off with a state point given by T,P and then we calculate each of the other possible output pairs in turn, and then try to re-calculate T,P from the new input pair. If we don’t arrive back at the original T,P values, there is a problem in the flash routine in CoolProp. For more information on how these figures were generated, see CoolProp.Plots.ConsistencyPlots

Note

You can download the script that generated the following figure here: (link to script), right-click the link and then save as… or the equivalent in your browser. You can also download this figure as a PDF.

Flash consistency (HEOS): 6 inconsistent, 0 exceptions, 0 bad-phase across 3 input pair(s).

Download full failure list (CSV)

Failing state points (sample, up to 20 per pair/class)

Pair	Class	Region	P [Pa]	T [K]	In1	Val1	In2	Val2	Error
DmolarP	INCONSISTENT	1phase	0.498156	183.65	Dmolar	7736.21	P	0.498156
DmolarP	INCONSISTENT	1phase	1.40009	194.326	Dmolar	7645.02	P	1.40009
DmolarP	INCONSISTENT	1phase	0.297146	183.65	Dmolar	7736.21	P	0.297146
DmolarP	INCONSISTENT	1phase	0.835143	183.65	Dmolar	7736.21	P	0.835143
HmolarSmolar	INCONSISTENT	2phase	0.205641	183.55	Hmolar	-41424.3	Smolar	-152.908
SmolarT	INCONSISTENT	1phase	0.835143	183.65	Smolar	-152.801	T	183.65

Superancillary Plots

The following figure shows the accuracy of the superancillary functions relative to extended precision calculations carried out in C++ with the teqp library. The results of the iterative calculations with REFPROP and CoolProp are also shown.

Note

You can download the script that generated the following figure here: (link to script), right-click the link and then save as… or the equivalent in your browser. You can also download this figure as a PDF.