Caloric Properties of Hydrocarbons in Liquid, Gaseous, and Supercritical States: n-Heptane

Detailed experimental data are presented on the n-heptane isobaric heat capacity obtained by a modernized adiabatic running calorimeter with the calorimetric measurement of the flow rate in the liquid, gaseous, and supercritical domains, within a temperature range of 300–620 K and a pressure range of 0.5–60 MPa. A thorough consideration of errors made it possible to obtain an error of 0.4% within a wide range of the state parameters. According to the experimental data on the heat capacity, using the known thermodynamics relations, the tables of the n-heptane enthalpy, entropy, and Gibbs energy were calculated (estimated against the accuracy) on the basis of the reliable state equations and the available literature data. The obtained results can be applied directly in the design of chemical processes and the processes in the bedded systems of the hydrocarbon deposits and for development and testing of the equations of state and the methods of the thermodynamic similarity.