Dear

**Zeiks**;

Even

**only one** Centigrade can be enough!

**Why?:** Your “Definition” of a “Simple Fractional Distillation with a Fractionating Column”(

**SFD/FD**) is nearly in all directions TOO, too weak!

That’s why also the O2/Argon is an

**SFD/FD** only at the correct low Temperature! (Of course, optimised!)

Do you know what the “

**Height Equivalent to a Theoretical Plate**” (

**HETP**) is and how it is defined?

But the HETP is by far not the only parameter who influences the Effectivity of every SFD/FD!

There are also such Parameters like: “

**Diameter**”, “

**Length**”, “

**Burden/Loading**”, “

**Reflux Ratio**”, etc., etc.

**But the Base of all** is the “

**Rauolt’s Law**” you may read on: "

Rauolt’s Law”

Only as an Example: HETP Parameter for only a “

**Vigreux Column**”:

Diameter [cm] HETP [cm]

2.4 ~ 11.5

1.2 ~ 5.4

0.6 ~ 2.9

But even these values are strong influenced by “

**Burden/Loading**” in mL per minutes!

And in the Attachment you can see the Influence of the “

**Reflux Ratio**” for three different Ratios (A1, A2, and A3).

**Hints:** **y** = Ratio of partial pressures in the gas phase.

**x** = Concentration of the liquid phase.

**X**_{B} = Starting Concentration.

**X**_{D} = Preferred End Concentration.

**A**_{1} = Situation, where you need

**infinite** Number of plates.

**A**_{2} = Situation, where success is assured in the Lab.

**A**_{3} = Situation, where Rectification is impossible.

In A.72. you see the Temperature Situation for Benzene Toluene during Distillation:

**a.)** SFD without FD.

**b.)** SFD/FD with a FD of ~12 “Theoretical Plates” and “Reflux Ratio” of 1:10.

**c.)** SFD/FD with a FD of ~12 “Theoretical Plates”, but condensing all Vapour.

(Also in this case a minimal “Reflux Ratio” exists.)

For

**HETP** you may also read on: "

Theoretical Plate”

I hope this is giving you at least an Idea, what you should all define before!

Good Luck!

ARGOS

^{++}