29-11-2012, 02:37 PM
Fundamentals: Thermodynamics
[attachment=41674]
Binary system representation
Liquid-vapor equilibrium of binary system can be graphically represented in several ways. The most common are: temperature-composition; pressure-composition; vapor-liquid mole fractions and enthalpy-composition.
One of the most convenient representation is the graph of mole fraction in gas phase versus mole fraction in liquid phase, y versus x. Generally x and y refer to the more volatile component.
In this case, the equilibrium curve is represented either at constant temperature or at constant pressure. In the latter case, the temperature changes along the curve as it is shown in the figure here below.
All the points on the equilibrium curve represent two phases (liquid and vapor) in equilibrium. All the other points in the diagram represent also two phases, but not at equilibrium.
[attachment=41674]
Binary system representation
Liquid-vapor equilibrium of binary system can be graphically represented in several ways. The most common are: temperature-composition; pressure-composition; vapor-liquid mole fractions and enthalpy-composition.
One of the most convenient representation is the graph of mole fraction in gas phase versus mole fraction in liquid phase, y versus x. Generally x and y refer to the more volatile component.
In this case, the equilibrium curve is represented either at constant temperature or at constant pressure. In the latter case, the temperature changes along the curve as it is shown in the figure here below.
All the points on the equilibrium curve represent two phases (liquid and vapor) in equilibrium. All the other points in the diagram represent also two phases, but not at equilibrium.