Where do heavy liquids go in a distillation unit?

Heavy liquids are found at the bottom of a distillation (fractionating) column. Distillation uses differences in boiling points. Small, light molecules have low boiling points and boil first, rising up to the top of the column where they can be condensed at lower temperatures. Heavier molecules have higher boiling points and condense further down the column where temperatures are higher.

In fractional distillation, the heavier fractions are collected at the bottom; where it is hottest. They have very long carbon chains and boiling points.

Heavier liquids condense at higher boiling points. The distillation tower is hotter at the bottom so heavier fractions/ liquids will collect at the bottom of the tower.