As nouns the difference between separate and bioseparation
is that
separate is (usually|in the plural) anything that is sold by itself, especially an article of clothing while
bioseparation is (biochemistry) the separation of the products of a biochemical reaction without damaging the organisms concerned.
As an adjective separate
is apart from (the rest); not connected to or attached to (anything else).
As a verb separate
is to divide (a thing) into separate parts.