The Static Method for Hpvle Experimentation
J. David Raal, Andreas L. Mühlbauer · 2023
Static equilibrium cells in a variety of configurations have been widely used for high-pressure vapour-liquid equilibrium measurement. This chapter discusses the unique and interesting features as well as the advantages and disadvantages of the static experimental methods are discussed with examples from the literature. The static method can be subdivided into analytical methods, in which both vapor and liquid compositions are sampled and analyzed, and the synthetic method, for which no sampling of the phases is required. The equilibrium cell temperature and pressure are regulated to generate the required vapor-liquid equilibrium isothermal or isobaric phase diagrams. When sampling the liquid phase in a volatile/nonvolatile system, the lighter component in the liquid phase flashes preferentially to the heavier component. In the static nonanalytical method a mixture of known composition is prepared and placed into an equilibrium cell. The mole fractions of substances making up the mixture can therefore be precisely calculated.