ABSTRACT

A new set of values for the heat capacity of aqueous mixtures of piperazine (PZ) and n-methyldiethanolamine (MDEA) at different concentrations and temperatures are reported in this paper. The differential scanning calorimetry technique was used to measure the property over the range T = 303.2 K to T = 353.2 K for mixtures containing 0.60 to 0.90 mole fraction water with 15 different concentrations of the system (PZ + MDEA + H2O). Heat capacity for four concentrations of the binary system (PZ + MDEA) was also measured. A Redlich Kister-type equation was adopted to estimate the excess molar heat capacity, which was used to predict the value of the molar heat capacity at a particular concentration and temperature, which would then be compared against the measured value. A total of 165 data points fit into the model resulted in a low overall average absolute deviation of 4.6% and 0.3% for the excess molar heat capacity and molar heat capacity, respectively. Thus, the results presented here are of acceptable accuracy for use in engineering process design.

Compounds

#	Formula	Name
1	C4H10N2	piperazine
2	C5H13NO2	N-methyldiethanolamine
3	H2O	water

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	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	5
POMD	1 3	Excess molar heat capacity, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 1; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	44
POMD	1 3	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 1; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	44
POMD	2 1	Excess molar heat capacity, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 1; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	44
POMD	2 1	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 1; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	44
POMD	2 1 3	Excess molar heat capacity, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 3; Liquid Mole fraction - 1; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	165
POMD	2 1 3	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 3; Liquid Mole fraction - 1; Liquid	Pressure, kPa; Liquid	Liquid	Small sample (50 mg) DSC	165

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Liquid heat capacity of the solvent system (piperazine + n-methyldiethanolamine + water)

Chen, Y.-R.[Yu-Ru], Caparanga, A. R.[Alvin R.], Soriano, A. N.[Allan N.], Li, M. -H.[Meng-Hui]

ABSTRACT