Distillation units are used to separate mixtures of liquids based on their boiling points. The process of distillation involves heating the mixture until it boils and then collecting the vapour that is produced. The vapour is then cooled and condensed back into a liquid form. The resulting liquid will have a higher concentration of the more volatile component of the mixture. Distillation units are used in many different types of plants such as oil refineries and chemical processing plants. The exact distillation unit process will depend on the specific application and the type of mixture being separated.