ANALYTICAL DETERMINATION OF THERMODYNAMIC AND KINETIC PARAMETERS AND THERMOPHYSICAL CHARACTERISTICS OF ESSENTIAL OILS FROM THE Lamiaceae FAMILY.

Essential oils are widely used in perfumery, cosmetics, food and other industries. In the present study, thermodynamic and kinetic parameters as well as thermophysical characteristics of essential oils from the Lamiaceae family were calculated. The three types of Mentha (piperita L., crispa L. and pulegium L.) and the two types of Thumys (vulgaris L. and serpyllum L.), which are grown in Bulgaria, were examined. The Gibbs free energy (-1255.4-5196.34 J/mol), enthalpy (113.01-391.02 J/mol), entropy (-2.44-19.73 J/mol K), activation energy (-3099.71-103.42 J/mol), internal energy (90.80-376.27J/mol) and Helmholtz energy (-5289.65-1229.89 kJ/mol) of the essential oils were calculated. The specific heat capacity (208.32-1361.99 J/kg K), thermal conductivity (299.42-334.75 W/m K), thermal diffusity (245.59-1169.96 m²/s) and kinematic viscosity (6.94-11.55 m²/s) of essential oils were determined. The calculated thermophysical characteristics: specific heat capacity, coefficient of thermal conductivity, thermal diffusity and kinematic viscosity can be used in the design of various heat exchangers (distillation apparatuses, florentine flask, cobation columns and condensator-cooler used in essential oil industry). [ABSTRACT FROM AUTHOR]