Phase equilibrium data for the binary system N,N-dimethylformamide + ethylene and + ethane at several temperatures up to 18 MPa

The ethylene (C2H4)–N,N-dimethylformamide (DMF) binary system at 293.25, 303.05 and 323.05 K and pressures up to 18 MPa presents only a vapor–liquid equilibrium (VLE) behavior. The ethane (C2H6)–N,N-dimethylformamide binary system behaves quite differently. In fact this latter displays not only a vapor–liquid equilibrium (VLE) behavior but also liquid–liquid equilibrium (LLE) and vapor–liquid–liquid equilibrium (VLLE) behaviors. The ethane–N,N-dimethylformamide binary system has been studied at 264.45, 278.55, 293.15 and 313.35 K up to 18 MPa. Both systems are correlated using the Peng–Robinson equation-of-state with Wong–Sandler mixing rules. A stability test based on the tangent plan criterion, as described by Michelsen, is carried out during the flash calculations made on the ethane–N,N-dimethylformamide binary system.