Water is separated from n-butanol in a system with two feeds. Feed (1left(mathrm{~F}_{1} ight.) (=100.0 mathrm{kmol} /

Question:

Water is separated from n-butanol in a system with two feeds. Feed \(1\left(\mathrm{~F}_{1}\right.\) \(=100.0 \mathrm{kmol} / \mathrm{h}, \mathrm{z}_{1}=0.84\) [mole fraction water], saturated vapor) is mixed with vapor leaving the top of the column before it is sent to the total condenser and then to the liquid-liquid settler. Feed \(2\left(\mathrm{~F}_{2}=80.0 \mathrm{kmol} / \mathrm{h}\right.\), \(\mathrm{z}_{2}=0.20\) [mole fraction water], saturated liquid) is fed within the column. The column has a partial reboiler, and CMO is valid. The top layer from the liquid-liquid settler \(\left(x_{0}=57.3 \mathrm{~mol} \%\right.\) water \()\) is sent as reflux to the distillation column. The bottom layer \(\left(\mathrm{x}_{\text {dist }}=97.5 \mathrm{~mol} \%\right.\) water \()\) is the water product. Pressure \(\mathrm{p}=1.0 \mathrm{~atm}\), reflux is a saturated liquid, \(v / \mathrm{B}=1.5\), \(\mathrm{x}_{\text {bot }}=4.0 \mathrm{~mol} \%\) water. Equilibrium data are in Table 8-5.
image text in transcribed a. Find \(\mathrm{D}\) and \(\mathrm{B}\) in \(\mathrm{kmol} / \mathrm{h}\).
b. Find \(\mathrm{v}, \mathrm{\sim}\) in the bottom section of the column, and find \(\mathrm{V}\) and \(\mathrm{L}\) in the section above feed 2, both in \(\mathrm{kmol} / \mathrm{h}\).
c. Derive the operating equation for the distillation section above feed 2 (flow rates \(\mathrm{V}\) and \(\mathrm{L}\) ).
d. Plot the operating lines, and step off stages starting at the reboiler and going up the column. Use the optimum feed stage for feed 2. Report the optimum feed stage above the partial reboiler and the total number of stages.