Question

The Enriching section operating line intercept at the origin in McCabe-Thiele method when

(a) Reflux ratio = Zero

(b) Reflux ratio= Infinity

(c) Reflux ratio= One

(d) Reflux ratio= 1.5 to 2 times Reflux minimum

I have been asked this question in a dream while sleeping

This interesting question is from Design of Fractionator with Mc-cabe Thiele Method in chapter Distillation of Mass Transfer

Answer 1

Right choice is (b) Reflux ratio= Infinity

Explanation: When the Enriching section operating line intercept at origin then the operating line will become the diagonal line (45 degree line) that means all the condenser product are refluxed( No distillate). i.e. Reflux  ratio =(R/D) if D=0 then reflux ratio tends to infinity that gives a minimum number of trays for designing the distillation column.