Modified freezing method for measuring the gas solubility along the solid–liquid–gas equilibrium line

A new experimental technique for fast and efficient determinations of gas solubility in the liquid phase along the solid–liquid–gas equilibrium line of the binary system was designed and tested. The new technique based on the observation of pressure and temperature changes in the experimental system while solid–liquid–gas equilibrium was established. Pressure–temperature–composition diagrams along the solid–liquid–gas equilibrium line for the binary systems biphenyl/CO2, vanillin/CO2, ethyl-o-vanillin/CO2 and benzoic acid/CO2 were determined up to 15.0 MPa and 423.2 K. These experimental data were plotted as (p–T) and (T–x) projections of three-phase solid–liquid–gas equilibrium line. Generally, it was observed that when the liquefaction temperature decreased along the three-phase solid–liquid–gas equilibrium line, the solubility of gas in the molten heavy component increased.