Question

Draw a diagram of bubble plate type fractionating column. When do we requir such type of a column for separating two liquids. Explain the principle involved in the separation of components of a mixture of liquids by using fractionating column. What industrial applications does this process have ?

Answer 1

If the difference in boiling points of two liquids is not much, fractional distillation is used. The techniques is, vapors of liquid mixture are passed through a fractionating column before condensation, fitted over the mouth of the round bottom flask.
Vapours of the liquid with higher boiling point condense before the vapours of the liquid with lower boiling point. The vapours rising up in the fractionating column become rich in more volatile component. Fractionating column provides may surfaces for heat exchange between ascending vapurs and descending condensed liquid. The vapurs become richer in low boiling component.

One of technological application of fractional distillation is to separate different fraction of crude oil in petroleum industly into various fractions like gasoline, kerosene oil, diesel oil, lubricating oil, etc.
Another application is the separation of acetone and methanol form pyroligneous acid obtained by destructive distillation of wood.