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Thermodynamics of 2-(1‘-Hydroxycyclohexyl)cyclohexanone: Vaporization, Sublimation, and the Ideal Gas State Thermodynamic Properties
journal contribution
posted on 2006-09-14, 00:00 authored by Marina P. Shevelyova, Dzmitry H. Zaitsau, Yauheni U. Paulechka, Gennady J. Kabo, Sergey P. VerevkinThe thermodynamics of one of the byproducts of caprolactam production, 2-(1‘-hydroxycyclohexyl)cyclohexanone
(ketol), have been studied in this work. Saturated vapor pressure for liquid and crystalline ketol was measured by
the Knudsen method in the temperature ranges from (308.2 to 330.4) K and from (289.6 to 300.8) K, respectively.
Additionally, the saturated vapor pressures over ketol in the undercooled state and in the liquid were measured
by the transpiration method in the temperature range from (287.9 to 303.0) K and from (308.0 to 351.5) K,
respectively. The enthalpy of vaporization and the enthalpy of sublimation of ketol at the average temperatures
studied were obtained indirectly from the temperature dependence of the vapor pressure measured by the Knudsen
method as well as by the transpiration method. Furthermore, the standard molar enthalpy of sublimation was
measured directly at 303.1 K using calorimetry. The entropy of ketol in the vapor state at (320.8 and 298.2) K
was derived. The thermodynamic properties for 2-(1‘-hydroxycyclohexyl)cyclohexanone in the ideal gas state
were calculated from statistical mechanic calculations in the broad temperature range from (50 to 1000) K. The
gaseous thermodynamic equilibrium constant K° (at 332.1 K) for cyclohexanone auto-condensation (side reaction
of the caprolactam production) leading to 2-(1‘-hydroxycyclohexyl)cyclohexanone was assessed.