Experimental apparatus for phase behavior study of solvent–bitumen systems: A critical review and design of a new apparatus

A new apparatus for studying the phase behavior of heavy oil and bitumen with different solvents has been tested. It has the capability of determining physical properties, such as density, viscosity, and compositions, of individual phases over a broad range of temperatures and pressures. One of the unique features of this apparatus is that the method of detecting presence of different phases is based on the values of density and viscosity of the phases rather than visual observation. Thus, the applicability of this apparatus is not restricted to fluids that are transparent to visible light. In addition, this apparatus allows taking samples from each phase for further analysis. The other unique feature of the apparatus is that it is designed for an expeditious thermodynamic equilibration using a rocking cell with a free-rolling ball inside which allows the effective agitation. The success of this design relies upon coupling advanced apparatus construction techniques with accurate density and viscosity measurement for phase detection. The experimental apparatus was tested for vapor–liquid, liquid–liquid, and vapor–liquid–liquid equilibrium systems; and, the results are in good agreement with data published in the literature.