ABSTRACT

(p,q,T) Measurements and visual observations of the meniscus for isobutane were carried out carefully in the critical region over the range of temperatures: 15 mK 6 (T Tc) 6 35 mK, and of densities: 7.5 kg Ae m 3 6 (q qc) 6 7.5 kg Ae m 3 by a metal-bellows volumometer with an optical cell. Vapor pressures were also measured at T = (310, 405, 406, 407, and 407.5) K. The critical point of Tc and qc was determined by the image analysis of the critical opalescence which is proposed in this study. The critical pressure pc was determined to be the pressure measurement at the critical point. Comparisons of the critical parameters with values given in the literature are presented.

Compounds

#	Formula	Name
1	C4H10	2-methylpropane

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	Critical pressure, kPa ; Liquid		Liquid Gas	Direct measurement	1
POMD	1	Critical temperature, K ; Liquid		Liquid Gas	Visual observation in an unstirred cell	1
POMD	1	Critical density, kg/m3 ; Liquid		Liquid Gas	Derived from PVT data	1
POMD	1	Vapor or sublimation pressure, kPa ; Liquid	Temperature, K; Liquid	Liquid Gas	Closed cell (Static) method	37
POMD	1	Mass density, kg/m3 ; Fluid (supercritical or subcritical phases)	Temperature, K; Fluid (supercritical or subcritical phases) Pressure, kPa; Fluid (supercritical or subcritical phases)	Fluid (supercritical or subcritical phases)	Bellows volumetry	59

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Critical parameters for isobutane determined by the image analysis

Masui, G., Honda, Y., Uematsu, M.

ABSTRACT