Developing a Thermodynamical Method for Prediction of Activity Coefficient of TBP Dissolved in Kerosene

Abstract

Results of the experimental measurements on the partial molar volume of kerosene used as a medium for dissolving TBP are utilized to determine the activity of TBP in the binary kerosene-TBP solution through the application of Gibbs-Duhem equation. The treatment is based on combination of the experimental data with the thermodynamic values available on the compressibility factor of pure kerosene at room temperature. It is shown that the activity of TBP in kerosene has a positive deviation from ideality with an activity coefficient derived as follows: 1) at X TBP ≤ 0.01: γ TBP = 42.530, 2) at the 0.01 < X TBP < 0.2: 3) at the higher TBP concentrations 0.2 < X TBP < 0.97: and 4) at TBP Raoultian concentrations 0.97 ≤ X TBP : γ TBP = 1. These quantities can be utilized at temperature closed to 298 K.