Vapor-liquid equilibrium data and density of the liquid phase for binary systems of carbon dioxide + methanol, hydrogen + methanol, and carbon dioxide + hydrogen at high pressures were determined. A dynamic technique with liquid-phase recirculation and on-line gas chromatography was used in this study. The equilibrium data and density were measured at temperatures between 278.15 K and 308.15 K, and pressures between 15 bar and 192.53 bar. The isothermal volume expansion behavior for the carbon dioxide + methanol system at various temperatures was also determined.