ABSTRACT
Figure 6.1 illustrates a two-phase pressure-temperature (PT)-flash process. A feed stream consisting of a mixture of N components is led to a flash separator kept at a constant temperature and pressure. Two phases are present in the separator. In a gas-oil separator, the gas is let out at the top and the oil at the bottom. If P, T, and component mole fractions in the feed (z1, z2, …, zN) are known, a flash calculation will provide the following results:
1. Number of phases. 2. Molar amounts of each phase. Figure 6.1 uses the term β for the vapor mole fraction. 3. Molar compositions of each phase. In Figure 6.1, the component mole fractions in the gas
phase are called (y1, y2, …, yN), and the component mole fractions in the liquid phase are called (x1, x2, …, xN).
