Pressure-temperature-composition data for the binary system composed of n-hexane and diethylamine have been determined over a range of conditions extending into the critical region. Dew, bubble and critical points at six compositions are reported in this paper. Vapor pressures and liquid densities of pure diethylamine are also reported. Phase equilibria in this nonpolar+polar system have been correlated using the Peng-Robinson (PR) equation. The PR equation is shown to work well for this weakly associating system although it fails to reproduce the detailed behavior of the critical locus. A remarkable feature of this binary system is that the critical locus is also the locus of points of maximum temperature (maxcondentherm) and pressure (maxcondenbar). As a consequence, there is no retrograde region in the system. The critical locus also exhibits a minimum in temperature which is characteristic of azeotropic behavior in the critical region.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry