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without reflux, uses/examples
used for separating components with wide boiling points
e.g flash distillation
with reflux use/exmaples
a purer product can be obtained
e.g fractional distillation, distillation with reflux
with trays or packed distillation columns
$$$ distillation
minimum and infinite R very expensive
for minimum more stages needed = more $
for infinite more operational cost cuz D=0
packed towers distillation uses
used when separation is relatively easy and the required column diameter is not very large
packed towers distillation uses adv/disadv
adv: cheap
disadv: difficulty in getting good liquid distribution