The first step in any process simulation is the definition of the chemical components involved and the selection of thermodynamic methods that may provide reliable values of k-values, enthalpy and other properties in the range of temperatures, pressures and composition encompassed by the process under study.

A component library with most common chemical components in the petrochemical industry is available.

The thermodynamic methods library is extremely rich as well as up-to-date. It contains a large number of methods (over 30 methods/models) for the calculation of thermodynamic (K-values, enthalpies, entropies, densities, etc.) and transport properties (viscosities, conductivities) of pure components and mixtures.

The user can modify component data or set up his own non-library components at the beginning of a simulation run.

XPSIM includes a number of correlations for the generation of thermodynamic properties of pseudo-components starting from NBP, density and molecular weight. It is also possible to automatically generate and characterize petroleum pseudo-components starting from ASTM or TBP distillation curves

On the calculation results, distillation curves are recalculated.