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

A new four-parameter cubic equation of state (EoS) is generated by incorporating the critical compressibility factor (Zc) apart from the critical pressure (Pc) and temperature (Tc). One free parameter in the denominator of the attractive term and two parameters in the alpha function are adjusted using the experimental data of saturated liquid density, vapor pressure, and isobaric liquid heat capacity of 48 components including hydrocarbons and non-hydrocarbons. Applying this equation of state, saturated liquid density, saturated vapor density, and vapor pressure of pure components are accurately reproduced compared with experimental values. Furthermore, the predicted properties including derivatives of alpha function, such as enthalpy of vaporization, entropy of vaporization and isobaric heat capacity of liquid, also have decent accuracy. The global average absolute relative deviation (AAD) of saturated liquid density, saturated vapor density, saturated vapor pressure, enthalpy of vaporization, entropy of vaporization, and isobaric heat capacity of liquid in a wide reduced temperature (Tr) range of subcritical region reproduced by this work are 4.33%, 4.18%, 3.19%, 2.26%, 2.27%, and 5.82%, respectively. Substantial improvement has been achieved for the isobaric liquid heat capacity calculation.

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Liquid Heat Capacity of Aqueous Solutions Containing Diethanolamine and 2-Piperidineethanol

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN ◽

10.1252/jcej.08we097 ◽

2008 ◽

Vol 41 (11) ◽

pp. 1011-1016 ◽

Cited By ~ 3

Author(s):

Tzn-Wei Shih ◽

Meng-Hui Li

Keyword(s):

Heat Capacity ◽

Aqueous Solutions ◽

Liquid Heat

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The heat capacities of certain liquids

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1957.0035 ◽

1957 ◽

Vol 239 (1217) ◽

pp. 230-246 ◽

Cited By ~ 27

Keyword(s):

Heat Capacity ◽

Carbon Tetrachloride ◽

Carbon Disulphide ◽

Heat Capacities ◽

Constant Volume ◽

Pressure Data ◽

Different Temperatures ◽

Structural Contribution ◽

Liquid Heat ◽

Total Heat Capacity

The heat capacities and adiabatic compressibilities of carbon tetrachloride, chloroform, methylene dibromide and m ethyl iodide have been measured between about — 30 and 30° C. The heat capacities at constant volume have been derived, and it is emphasized th a t these quantities apply to particular volumes existing at different temperatures. An isotherm for liquids, based on high-pressure data, has been used to obtain an expression for the effect of change of volume on the heat capacity at constant volume. This relation has been applied to mercury, carbon disulphide, carbon tetrachloride, chloroform and water. Satisfactory agreement has been obtained with the results found in other ways by Bridgman (1911, 1912) on mercury and water and by Gibson & Loeffler (1941) on carbon tetrachloride and water. From the results found in this work on the resolution of the various energy contributions to the liquid heat capacities of polyatomic molecules other than water, it is concluded that the concept of molecular rotation about a preferred axis can explain most of the facts established. There remains, however, a structural contribution to the total heat capacity which is approximately R cal mole -1 deg. -1 .

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