Steam distillation is a common way to extract oils from natural materials (i.e. getting clove oil from cloves, which I remember doing as an undergraduate). The reason...you don't have to use as much heat to achieve the distillation. Check out the wikipedia site. Another distillation that wouldn't be bad is vacuum distillation, where instead of using steam you use a vacuum to reduce pressure.
6 Answers · Science & Mathematics · 03/08/2009