A stripping column with two feeds is separating acetone and ethanol at \(1 \mathrm{~atm}\). Feed \(\mathrm{F}_{1}\) is a saturated liquid and is fed into the top of column (no condenser). Flow rate of \(F_{1}\) is \(100 \mathrm{kmol} / \mathrm{h}\), and this feed is \(60 \mathrm{~mol} \%\) acetone. Feed \(F_{2}\) is \(40 \mathrm{~mol} \%\) acetone, it is a two-phase feed that is \(80 \%\) vapor, and flow rate is \(80 \mathrm{kmol} / \mathrm{h}\). Bottoms is \(4 \mathrm{~mol} \%\) acetone. The column has a partial reboiler. VLE data are in Problem 4.D7.

 Problem 4.D7

a. Calculate \((/ / B)_{\min }\).

b. If \((/ / B)=1.5\), find \(D\) and \(y_{D}\), the optimum feed stage for feed \(F_{2}\), and the total number of stages. Step off stages from the bottom upward.

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D7.* A distillation column with a total condenser is separating a feed that is 30 mol% acetone from ethanol. Distillate xD = 0.90, and bottoms XB = 0.13, both mole fractions acetone. Assume CMO is valid. L/V = 0.8. Boilup ratio is /B = 1.0. a. Find the composition of the liquid leaving the fifth stage below the total condenser. b. The column has a partial reboiler that acts as an equilibrium contact. Find the vapor composition leaving the second stage above the partial reboiler. c. Find optimum feed plate location, total number of stages, and required q value of feed. Equilibrium data for acetone (A) and ethanol at 1 atm (Perry et al., 1963, pp. 13-4): XA O 0.10 0.15 0.20 YA O TC 78.3 0.50 0.35 0.40 1.0 0.25 0.30 0.60 0.70 0.80 0.90 0.262 0.348 0.417 0.478 0.524 0.566 0.605 0.674 0.739 0.802 0.865 0.929 1.0 67.3 65.9 - 63.6 - 60.4 59.1 58.0 57.0 56.1