Distillation Problem Solving Drill

Distillation Problem Solving Drills

1. One hundred moles per hour of solution containing 80 moles of A, the rest is subjected to a simple continuous distillation. D moles of distillate containing 72 moles A is obtained. If A is five times more volatile than B, what is the concentration of A in the distillate? 2.A 50% by weight benzene-toluene mixture is fed to a column at 180oF and 1 atm. What is the condition of the feed? (saturated liquid, saturated vapour, subcooled liquid or mixture of vapour and liquid). 3.A 537 kg solution of 50% by weight heptane and 50% by weight octane is batch-distilled until only 4.74 lbmol remain in the still. If the relative volatility is 2.0, what is the composition of the final liquid mixture?

4. An enriching tower is fed 100 kgmol/hr saturated vapor feed containing 40 mol % benzene (A) and 60 mol % toluene (B) at 101.32 kPa abs. The distillate is to contain 90 mol % benzene. The reflux is set at 4:1. Calculate the kg mol/h distillate D and bottoms Wand their composition. Also, calculate the number of theoretical plates required. Study also the concepts summarized in the Introduct Introduction to Distillation that can be found in http://lorien.ncl.ac.uk/ming/distil/distil0.htm