CRITICAL CURVES AND PHASE-EQUILIBRIA OF BINARY METHANOL-SYSTEMS FOR HIGH-PRESSURES AND TEMPERATURES

The critical curves of binary systems of methanol combined with CH4, N -2, H-2, CO and CO2 have been determined experimentally up to 100 MPa and higher by Brunner. Tn the present work a rational equation of stat e of the perturbation type with a repulsion and an attraction term has been applied to reproduce these critical curves up to high pressures. A square well potential for intermolecular interaction is used. With pairwise combination rules for these potentials three adjustable param eters are needed. Values for these parameters, obtained from the fitti ng of the critical curves are used to calculate isotherms of the two-p hase high pressure equilibrium surfaces for the four systems of methan ol combined with CH4, N-2, H-2, and CO. Three of these have not yet be en investigated experimentally. It is suggested to use this procedure for predictions of the extent of three-dimensional two-phase regions i n temperature-pressure-composition spaces.