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. Pres sure-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.