Rectification is a thermal separation process in which the more volatile components of a mixture are recovered and concentrated. The supply of thermal energy vaporizes the more volatile components and the ascending vapor phase comes into contact with descending liquid (reflux of volatile components).
Part of the condensate is discharged as top product. The reflux contact normally occurs in trays or packages installed in a column. Increasing the number of rectification steps increases the concentration of the most volatile component. This means that the concentration of the low-volatile component is increased by the forwarding of the top product of the first rectification column into a second column.
Rectification is commonly used to purify alcohols, but usually ground streams are used to preheat the cold stream and optimize overall energy requirements. By combining with other technologies than mechanical vapor recompression, there are a variety of other uses.
and much more.