Question

The vertical D/F line indicated the

(a) Maximum impurity level

(b) Minimum impurity level

(c) More separation

(d) Less separation

I have been asked this question in examination.

This intriguing question comes from Process Design and Optimization topic in chapter Column Process Design, Optimization and Shortcut Calculations of Distillation Design

Answer 1

Right answer is (a) Maximum impurity level

To explain: The vertical D/F line indicated the Maximum impurity level at that point on the curve, and this should has to be minimized for better operations.