[fingers]

Hi all

I was wondering if there is anyone out there who could shed some light on this question please.

180kmol/hr of a three component mix is made up of 60mol% A, 25mol% B and 15mol% C.
The mixture is to be seperated by continuous distillation in 2 columns so that 80% of C in the feed is removed as bottom product in the first column as a 90mol% solution with B.

The top product from the first column will be seperated in the second column to give a top product here of 95mol% A and a bottom product of 85mol% B.

Determine the flows from  the 2 columns and the mol% A in the bottom product from column 2.

Assume there is to be no A in the bottom product of column 1 and no C in the top product of column 2.

My answer : Calc component C.
0.15x180 = 27 and 80% of this is removed in the bottom stream of column 1.
Thus 80% of 27 = 21.6km/hr of C in the bottom stream

Also it says that C is 90% of the bottom stream thus the other 10% of the bottom stream would be B as there is no A in the bottom product of column 1.

So i know the % of the bottom but how do i calculate the top % for the column?

Would be great if someone could shed some light on this please.

[Borek]

So i know the % of the bottom but how do i calculate the top % for the column?

Isn't it simply the original feed minus whatever you calculated is removed at the bottom? That would be just a mass balance.