PHASE-EQUILIBRIA OF BINARY AND TERNARY N-ALKANE SOLUTIONS IN SUPERCRITICAL ETHYLENE, 1-BUTENE, AND ETHYLENE PLUS 1-BUTENE - TRANSITION FROMTYPE-A THROUGH LCST TO U-LCST BEHAVIOR PREDICTED AND CONFIRMED EXPERIMENTALLY

Binary phase equilibria of C20 +, C30 +, and C40 + ethylene are correl ated with three equations of state, the Redlich-Kwong-Soave (Soave), t he generalized van der Waals-Prigogine (vdW-P), and the statistical as sociating fluid theory (SAFT), with special emphasis on the mixture cr itical region. The SAFT correlation is found to be the most reliable. SAFT predictive powers are tested on C26 + ethylene and a new set of e xperimental data taken in this work for C36 + 1-butene and C36 + ethyl ene + 1-butene. The SAFT predictions are found to be in good agreement with the experimental data. Equally important, the SAFT predictions a llow for understanding the continuous transition of phase behavior, fr om type A (C36 + 1-butene) through LCST (C36 + ethylene + 1-butene) to U-LCST (C36 + ethylene).