New generalized equations for the calculation of isobaric heat capacity of hydrocarbons at the saturation curve

The experimental data obtained by the authors on the isobaric heat capacity of $n$-alkanes on the saturation curve in the liquid phase and the literature data on $C'_p$ of hydrocarbons representing different homologous series are used to analyze the known formulas recommended for predictions of $C'_p$. It is demonstrated that, in order to increase the accuracy of calculations, one needs, first of all, to refine the description of heat capacity in the vicinity of the temperature of the triple point. The universal behavior of the temperature dependence of $C'_p$ in the vicinity of the triple point temperature is revealed. Based on these findings, new generalized equations are developed, which are recommended for the calculation of $C'_p$ of hydrocarbons in the temperature range from the triple point to critical.