Detection and measurements of high pressure VLE and LLE - PvT data of binary mixtures through the vibrating tube densitometer technique

The feasibility of detecting equilibrium states and measuring, simultaneously, saturated liquid densities and equilibrium pressures at fixed temperature, of "Type V" mixtures in state regions where both VLE and liquid-liquid equilibria (LLE) are present was evaluated. The employed technique was the Synthetic Indirect PvT Method through a single vibrating tube densitometer setup. The topologies and data analysis obtained for synthetic mixtures of ethane + n-propanol at different temperatures in the region where they present liquid-liquid in-miscibility encompassing LLE and VLE at near critical conditions were presented. The technique proved to be efficient for this kind of measurements, even if the first data comparisons suggested that, for the particular case of the mixture ethane + n-propanol, the measured data should be validated with another method and the same fluids. This is an abstract of a paper presented at the AIChE 2004 Annual Meeting (Austin, TX 11/7-12/2004).