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Unformatted text preview: : (a) In Fig. 7.37, below, the bubble point for 30 mol% nC6 in nC8 is shown as point B, which corresponds to a temperature of 211oF. An equilibrium tie line is drawn from point B to point M at the intersection with the saturated vapor line. The vapor composition at point M is 69 mol% nC6 and 31 mol% nC8.
(b) From Fig. 7.37, reproduced below, the enthalpy of the initial mixture of 20 mol% nC6 at 100oF, shown at point G, is 6,500 Btu/lbmol = HG . A vertical line is drawn upward from point G until it reaches the point E, located on the dashed tie line between the saturated liquid and saturated vapor curves, at a point that is 60% of the way from the saturated liquid curve to the saturated vapor curve. The enthalpy of the twophase mixture at point E is 23,000 Btu/lbmol = HE. Therefore, the energy required = Q = HE  HG = 23,000  6,500 = 16,500 Btu/lbmol. (c) From the reproduction of Fig. 7.37 below, the equilibrium liquid phase composition is at point D, which is 7.5 mol% nC6 , while the equilibrium vapor composition is at po...
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 Spring '06
 selebi
 Distillation, pH, Mass Transfer

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