From the given vapor liquid equilibrium data the

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Unformatted text preview: por-liquid equilibrium data, the highest concentration is an ethanol mole fraction of 0.82. (c) Since the bottom vapor feed, V0 = 100 mol and D = 50 mol, by overall material balance, L1 = V0 - D = 100 - 50 = 50 mol. Because of the assumption of constant molar overflow, L = LR = L1 = 50 mol. By material balance around the condenser or because of constant molar overflow, V = V4 = LR + D = 50 + 50 = 100 mol. The slope of the operating line from Eqs. (7-6) or (7-11) = L/V = 50/100 = 0.5. To determine the compositions of D and L1 for 4 stages, an operating line of this slope is located so that exactly 4 stages are stepped off in a y-x diagram, as shown below. From the diagram, the ethanol compositions are 45 mol% in D and 16 mol% in L1. (d) Since the distillate is 50 mol% ethanol, 25 moles of ethanol and 25 moles of water leave in the distillate. Because the feed is 30 moles of ethanol and 70 moles of water, L1 , the leaving liquid, contains 5 moles of ethanol and 45 moles of water. Thus, the termina...
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