Distillation Column

Batch Columns 

In batch operation, the feed to the column is introduced batch wise. That is the column is charged with a batch and then the distillation process is carried out.  When the desired task is achieved, a next batch of feed is introduced.
Continuous Columns 
In Contrast, continuous columns process a continuous feed stream. No interruptions occur un there is a problem with the column or surrounding process units. They are capable of handling high throughputs and are the most common of the two types.  We shall concentrate  only on this class of columns. The vertical shell houses the column internals and together with the condense & reboiler constitute a distillation column.   Separation of components from a liquid mixture via distillation depends on the differences in boiling points of the individual components.  Also, depending on the concentrations of the components present, the liquid mixture will have different boiling point characteristics depends on the vapour pressure characteristics of liquid mixtures.