1. A plant must distill a mixture containing 75 mole percent methanol and 25 percent water. The overhead product is to contain 99.99 mole percent methanol and the bottom product 0.002 mole percent. The feed is cold, and for each mole of feed 0.15 mole of vapor is condensed at the feed plate. The reflux ratio at the top of the column is 1.4, and the reflux is at its bubble point. Calculate:
a. the minimum number of plates
b. the minimum reflux ratio
c. the number of plates using a reboiler and a partial condenser operating with the reflux in equilibrium with the vapor going to a final condenser
Equilibrium data include:
|
X
|
.1
|
.2
|
.3
|
.4
|
.5
|
.6
|
.7
|
.8
|
.9
|
1.0
|
|
y
|
.417
|
.579
|
.669
|
.729
|
.780
|
.825
|
.871
|
.915
|
.959
|
1.0
|
2. What is the assumption named associated with nearly equal molar heats of vaporization, so that each mole of high boiler condenses and provides energy to vaporize about 1 mole of low boiler?