Other distillation techniques

Some distillation processes, other than special distillation processes, are carried out in special circumstances relative to ordinary distillation. In this chapter, they are emphasized and can be divided into three types: (1) those that have been applied in special distillation processes, such as high viscosity material distillation and thermally coupled distillation; (2) those that have the potential for use in special distillation processes, but not yet, such as heat pump and multieffect distillation; and (3) those that themselves, in principle, can be used as special distillation processes for separating mixtures with close boiling point or forming azeotrope but actually aren’t economic, such as molecular distillation. In this chapter, only the first type is clarified in detail since it is related to our topic, and the others are briefly mentioned.