ABSTRACT

The thermal behavior, upon heating, was studied for four alkanes: eicosane, tetracosane, triacontane, and tetracontane at pressures from (10 to 150)MPa. Using a transitiometer, the calorimetric signal, pressure, and temperature were measured at a very slow heating rate to guarantee thermal equilibrium. It was found that from the compounds studied, eicosane was the only one that did not present a solid solid transition; the other compounds show a solid solid transition a few Kelvin below the solid liquid transition temperature. This solid solid transition disappears when the pressure is increased in a triple point of type: solid + solid + liquid.

Compounds

#	Formula	Name
1	C20H42	eicosane
2	C24H50	tetracosane
3	C30H62	triacontane
4	C40H82	tetracontane

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Phase	Method	#Points
POMD	1	Solid-liquid equilibrium temperature, K ; Crystal	Pressure, kPa; Crystal	Crystal Liquid	DTA	5
POMD	2	Vapor or sublimation pressure, kPa ; Crystal 2		Crystal 2 Crystal 1 Liquid	UNKNOWN	1
POMD	2	Triple point temperature, K ; Crystal 2		Crystal 2 Crystal 1 Liquid	DTA	1
POMD	2	Solid-liquid equilibrium temperature, K ; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2 Crystal 1	DTA	4
POMD	2	Solid-liquid equilibrium temperature, K ; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1 Liquid	DTA	7
POMD	3	Vapor or sublimation pressure, kPa ; Crystal 2		Crystal 2 Crystal 1 Liquid	UNKNOWN	1
POMD	3	Triple point temperature, K ; Crystal 2		Crystal 2 Crystal 1 Liquid	DTA	1
POMD	3	Solid-liquid equilibrium temperature, K ; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2 Crystal 1	DTA	4
POMD	3	Solid-liquid equilibrium temperature, K ; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1 Liquid	DTA	7
POMD	4	Vapor or sublimation pressure, kPa ; Crystal 2		Crystal 2 Crystal 1 Liquid	UNKNOWN	1
POMD	4	Triple point temperature, K ; Crystal 2		Crystal 2 Crystal 1 Liquid	DTA	1
POMD	4	Solid-liquid equilibrium temperature, K ; Crystal 2	Pressure, kPa; Crystal 2	Crystal 2 Crystal 1	DTA:UFactor:2	4
POMD	4	Solid-liquid equilibrium temperature, K ; Crystal 1	Pressure, kPa; Crystal 1	Crystal 1 Liquid	DTA:UFactor:2	7

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

High pressure solid solid and solid liquid transition data for long chain alkanes

Machado, J. J. B.[Jose J. B.], de Loos, T. W.[Theo W.], Ihmels, E. C. C.[E. Christian], Fischer, K.[Kai], Gmehling, J.[Jurgen]

ABSTRACT