ABSTRACT

Propylene glycols (mono- and di-) have an important potential as solvents in liquid liquid extraction of aromatics and in azeotropic distillation. Literature and databases provide few accurate experimental data on liquid liquid and vapor liquid equilibria in systems consisting of propylene glycols and hydrocarbons (paraffinic, naphthenic, and aromatic hydrocarbons). However, an increasing interest in this field can be observed in recent years. This paper reports the results of an experimental study on the liquid liquid equilibria in binary systems consisting of dipropylene glycol and paraffinic, naphthenic, and aromatic hydrocarbons with six, seven, and eight atoms of carbon. The experimental data were obtained in a high-precision thermostatic equilibrium cell. The first and most important result was that all normal paraffinic and naphthenic hydrocarbons are partially miscible with dipropylene glycol (4-oxa-2,6-heptanediol), whereas aromatics are completely dissolved. To obtain the binary interaction parameters of the Non-Random Two-Liquid (NRTL) activity coefficients, a regression procedure was applied to the experimental data (only for normal paraffinic and naphthenic hydrocarbon dipropylene glycol systems) for each measured system. The NRTL parameters of the partially miscible binaries (complemented by the NRTL parameters for completely miscible binaries) can be subsequently used for simulations of liquid liquid extraction, solvent recovery, and extractive-distillation processes.

Compounds

#	Formula	Name
1	C6H14	hexane
2	C6H12	cyclohexane
3	C7H16	heptane
4	C8H18	octane
5	C8H18	2,2,4-trimethylpentane
6	C6H14O3	4-oxa-1,7-heptanediol

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	Constraint	Phase	Method	#Points
POMD	1 6	Mole fraction - 1 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Titration method	8
POMD	1 6	Mole fraction - 1 ; Liquid mixture 2	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 2 Liquid mixture 1	Titration method	8
POMD	2 6	Mole fraction - 2 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Titration method	10
POMD	2 6	Mole fraction - 2 ; Liquid mixture 2	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 2 Liquid mixture 1	Titration method	10
POMD	3 6	Mole fraction - 3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Titration method	10
POMD	3 6	Mole fraction - 3 ; Liquid mixture 2	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 2 Liquid mixture 1	Titration method	10
POMD	4 6	Mole fraction - 4 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Titration method	12
POMD	4 6	Mole fraction - 4 ; Liquid mixture 2	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 2 Liquid mixture 1	Titration method	12
POMD	5 6	Mole fraction - 5 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Titration method	10
POMD	5 6	Mole fraction - 5 ; Liquid mixture 2	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 2 Liquid mixture 1	Titration method	10

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Liquid Liquid Equilibria for Dipropylene Glycol Hydrocarbon Binary Systems: Experimental Data and Regression

Nicolae, M.[Marilena], Oprea, F.[Florin]

ABSTRACT