Verdampfungsgleichgewichte und kritische Kurven in den Systemen Äthan/Wasser und n‐Butan/Wasser bei hohen Drücken

Abstract

Die mit einem statischen Verfahren gemessenen Gleichgewichtszusammensetzungen der gasförmigen und flüssigen Phasen im System Äthan/Wasser werden zwischen 200 und 400°C bis zu Drücken von 3700 bar und für das System n‐Butan/Wasser bei 355 und 364°C bis zu Drücken von 1100 bar angegeben. In beiden Systemen ist die kritische Kurve unterbrochen. Ihr oberer Zweig verläuft vom kritischen Punkt des Wassers ausgehend zu niedrigeren Temperaturen, erreicht ein Temperaturminimum (350°C bei Äthan/Wasser und 351°C bei n‐Butan/Wasser) und wendet sich dann wieder zu höheren Temperaturen. Die kritischen Drücke steigen vom kritischen Druck des Wassers ausgehend monoton an.

Phase equilibria in water containing binary systems from molecular based equations of state

“…The effect of n-alkane chain length on phase equilibria has received considerable experimental attention [62][63][64][65]. Gas-gas immiscibility of the second kind exists for all the n-alkanes although the results of Tsiklis and Maslennikova [66] describing immiscibility of the first kind for n-butane + water seem to be incorrect.…”

Phase Equilibria in Binary and Ternary Hydrothermal Systems

“…However, it should be mentioned that the temperature maximum on the critical curve in the case of gas = gas equilibrium, as it was predicted by van der Waals (1894), has not been found experimentally up to now, only the rise of critical temperature with pressure (up to 100 kbar (Van den Bergh et al, 1987;Van den Bergh and Shouten, 1988)) was observed in number of binary mixtures. Aqueous systems with non-polar volatile components, such as Ar (Tsiklis and Prokhorov, 1966;Tsiklis, 1969;Wu et al, 1990), methane (CH 4 ) (Brunner, 1990;Shmonov et al, 1993), ethane (C 2 H 6 ) (Danneil et al, 1967;Brunner, 1990), CO 2 (Todheide and Franck, 1963;Takenouchi, S. and Kennedy, G.C., 1964); Kr (Mather et al, 1993); H 2 (Seward and Franck, 1981); N 2 (Japas and Franck, 1985a); O 2 (Japas and Franck, 1985b); Xe (Franck et al, 1974), where water is less volatile component, are characterized by the high-temperature critical curves (starting in the critical point of water) with temperature minimum (type 2 of gas = gas equilibrium). Same type of phase behavior was observed in hydrocarbon -water systems (Figure 1.21 (Schneider, 1970(Schneider, , 1978Brunner, 1990;Smits et al, 1998).…”

Calculation of vapor–liquid equilibrium and PVTx properties of geological fluid system with SAFT-LJ EOS including multi-polar contribution. Part III. Extension to water–light hydrocarbons systems

“…Unfortunately, they used inaccurate VLE data of the H 2 O-CH 4 and H 2 O-C 2 H 6 system for parameterization (i.e. the data of Sultanov et al (1972) and Danneil et al (1967) whose inaccuracy will be discussed in Section 3.1). Nguyen-Huynh et al (2011) and Papaioannou et al (2011) made progress in the quality of the calculation of vapor-liquid equilibria of some water-light hydrocarbon mixtures.…”