11.1.- UNIT OPERATIONS

These operations can be divided into three types:

• Mass transfer. A change in the mass or composition of the matter, which may include a chemical change. These operations are distillation, absorption, adsorption, extraction and ion exchange, in which the change is mainly physical.
• Energy transfer. Energy change that, for example, may suppose a change of state due to a change of pressure and/or temperature. This classification includes the evaporation, although other operations that combine energy transfer with mass transfer (drying, lyophilization, sublimation, crystallization and humidification) are also included.
• Momentum transfer. Change in the kinetic conditions of matter. The operations involving a kinetic change are filtration, sedimentation, flotation and centrifugation.

All of them are experimentally based on the corresponding conservation laws.

This type of operations is used in multiple industries. They are the basis of a wide range of processes from different fields of application, as for example the food industry, the energy industry, etc.