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Unformatted text preview: of a mixture of toluene and phenol for a given boilup ratio, with an alternative using an interreboiler. Given: 1,000 kmol/h of a saturated liquid feed of 25 mol% toluene. Distillate is 98 mol% toluene and bottoms is 2 mol% toluene. The base unit consists of a total condenser, a plate column, and a partial reboiler, with a boilup ratio, VB = V / B = 1.15 times minimum. The alternative unit adds an interreboiler midway in the stripping section to provide 50% of the boilup. A table of T-y-x phase equilibrium data Assumptions: Constant molar overflow. Find: For each unit, determine the number of theoretical stages. For the alternative unit, determine the temperature of the interreboiler stage. Analysis: Toluene is the more volatile unit. Base unit: From the McCabe-Thiele diagram below, the minimum boilup ratio is determined from the slope of the stripping section operating line that intersects the equilibrium curve at the feed composition of xF = 0.25. ( L /V )
From Eq. (7-28), min = 0.815 - 0.02 = 3.46 0.25...
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