Question

Find the distillate and the residue rates in mole/hr, if the feed rate is 100 mol/hr; The compositions of feed, distillate and residue in terms of mole fraction are 0.65, 0.9 and 0.2.

(a) 36,64

(b) 64,36

(c) 20,80

(d) 80,20

This question was addressed to me in an online interview.

The query is from Distillation in section Distillation of Mass Transfer

Answer 1

Correct choice is (b) 64,36

The explanation: F*xf= D*xd+ W*xw

On applying the values, we get distillate rate= 64 mol/hr and residue rate is 36 mol/hr.