The method we recently described for estimating critical properties of
hydrocarbons using experimental vapour pressure and density data (VPD
method) was modified in order to be applicable to compounds with very
low vapour pressures. Accordingly, it was possible to estimate the no
rmal boiling temperature, critical temperature and critical pressure o
f every hydrocarbon for which vapour pressures and liquid densities we
re known. In the case of high molecular weight compounds, the critical
parameters of which are beyond the scope of reliable experiments, thi
s method constitutes a valuable source of information.