# hw 8 - concentration of this liquid phase Problem 3...

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ChEn 2001, Homework #8 Due Friday, November 20, 2009 Problems 2-4 use the Txy data that you generated for ethylbenzene and toluene on Homework #7. If you did not get this problem correct on the previous homework, you should download the solution from WebVista. If you use the wrong equilibrium data here, you will get the problems wrong. Problem 1. Consider a 10 stage rectifying column that produces 100 moles/hr of distillate at 99.9% purity and 150 moles/hr of liquid at the bottom of the column. The equilibrium relationship for the column is given by y * n = 0 . 67 + 0 . 33 x * n Determine the fractional recovery of the distillate using the Kremser equation. Do you think the model stated here is likely to be accurate? Explain your reasoning. Problem 2. Consider a rectifying column for ethylbenzene and toluene at 600 mmHg. The distillate is 97% pure and the column operates with a reﬂux ratio of 2.2. Determine (i) how many stages are required to have a liquid product that is contains less than 70% toluene and (ii) the
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Unformatted text preview: concentration of this liquid phase. Problem 3. Consider a stripping column for ethylbenzene and toluene at 600 mmHg. The stripping column consists of three stages and the reboiler. The liquid feed at the top is 600 mol/hr and the bottoms produces a 150 mol/hr stream of 94% ethylbenzene. Determine the composition of each liquid stream in the system ( x , x 1 , x 2 and x 3 ) as well as the gas streams ( y 1 , y 2 , y 3 and y 4 ). Check the quality of your triangle drawing by comparing your ﬁnal results to the overall balance on toluene. Problem 4. Consider a distillation column for ethylbenzene and toluene at 600 mmHg. The column takes a saturated vapor feed of 60% toluene at the optimal feed location. The distillate and bottoms are both 90% purity and the column operates at 1.3 times the minimum reﬂux ratio. Determine (i) the location of the feed tray and (ii) the ratio of the number of stages of the column relative to the minimum number of stages. 1...
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## This note was uploaded on 10/30/2011 for the course CHEN 2001 taught by Professor Dorfman during the Fall '08 term at Minnesota.

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