Three phase equilibria in binary mixtures of ethane and higher n-alkanes

Abstract

In binary mixtures of ethane + higher n-alkanes a systematic change in phase behaviour with increasing carbonnumber near the critical point of ethane can be observed. Binaries up to C 17 are completely miscible in the liquid phase and binaries up to C 23 show partial miscibility in the liquid phase with an upper and lower critical endpoint. In the binaries of ethane with C 24 and C 25 the three phase equilibrium solid n-alkane + liquid + vapour intersects the three phase equilibrium liquid + liquid + vapour and a quadruple point solid n-alkane + liquid + liquid + vapour can be observed. As the carbonnumber further increases stable liquid + liquid phasesplit will be obscured by solidification. In this contribution experimental results for the binaries C 2 + C 16, C 2 + C 20, C 2 + C 22, C 2 + C 23, C 2 + C 24, C 2 + C 25 and C 2 + C 26 will be reported and shown to present a logical evolution in phase behaviour.