Question

HETP is numerically equal to HTU, If and only if operating line

(a) Lies below the equilibrium line

(b) Lies above equilibrium line

(c) At equilibrium line

(d) Is far from equilibrium line

I have been asked this question in a job interview.

The above asked question is from Minimum Reflux for System Containing Distributed Monkeys topic in division Column Process Design, Optimization and Shortcut Calculations of Distillation Design

Answer 1

Right option is (c) At equilibrium line

To explain: HETP is numerically equal to HTU if and only if operating line is parallel to equilibrium line, this means NTU i.e. number of transfer units are unity.