You are considering the behavior of a ternary mixture of methane, propane, n-pentane at 160'F. At an initial pressure of 2350 psis do you anticipate that a mixture of 40.2 mole % methane, 40.1 mole % n-pentane and 19.7 mole % propane is single phase or two phase? If single phase is it a liquid or a gas. If it is phase separated, what are the compositions of the liquid and gas? Justify (b) Consider the system in (a) and the pressure is now reduced to 500 psia. If the co-existing phases of liquid vapor have the compositions of (Liquid Xmethane=0.123; Xn-pentane=0.606) and (Gas Ymethane=0.923; Yn_pentane=0.018) respectively, then determine the fraction of the original mixture that is a liquid and the fraction that is vapor. Derive the necessary relations.
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Fig. 2-28 Ternary phase-diagrams of mixtures of methane, propane, and n-pentane at 160 degree F and various pressures, showing typical change in shapes of the diagrams as pressure is changed. (Diagram numbers are keyed to the numbered points on Figure 2-28).