*Answers to problems with an asterisk are at the back of the book.
D1.* We have 10 kmol/h of a saturated liquid feed that is 40 mol% benzene and 60 mol% toluene. We desire a distillate composition that is 0.992 mole fraction benzene and a bottoms that is 0.986 mole fraction toluene (note units). CMO is valid. Assume constant relative volatility with αBT = 2.4. Reflux is returned as a saturated liquid. The column has a partial reboiler and a total condenser.
a. Use the Fenske equation to determine Nmin.
b. Use the Underwood equations to find (L/D)min.
c. For L/D = 1.1(L/D)min, use the previous results and the Gilliland correlation to estimate the total number of stages and the optimum feed stage location.
D2. We are separating a mixture ...