stripping tower and direct steam injection

Stripping Tower and Direct Steam Injection A liquid feed at the boiling point contains 3.3mol% ethanol and 96.7mol% water and enters the top tray of a stripping tower. Saturated steam is injected directly into the liquid in the bottom of the tower. The overhead vapor that is withdrawn contains 99% of the alcohol in the feed. Assume equimolar overflow for this problem. Equilibrium data for mole fraction of alcohol are follows at 101.32kPa abs pressure (1 atm abs): (a) For an infinite number of theoretical steps, calculate the minimum moles of steam needed per mole of feed. (Note: Be sure to plot the q line.) (b) Using twice the minimum moles of steam, calculate the number of theoretical steps needed, the composition of the overhead vapor, and the bottoms composition. Ans. (a) 0.121mol steam /mol feed; (b) 5.0 theoretical steps, x0=0.135,xW=0.00033