Introduction

Mass transfer operations are directed towards separating a substance into its component parts.

• For mixtures, such separations may be entirely mechanical, e.g. the filtrations of a solid from a suspension in a liquid, or the separation of particles of a solid mixture according to their density. These aspects are covered in Mechanical Unit Operations (or, simply Mechanical Operations).

• On the other hand, if the operations involve changes in composition of solutions, they are known as Mass Transfer operations.

The importance of mass-transfer operations in chemical engineering is profound. There is scarcely any chemical process which does not require either a preliminary purification of raw materials or a final separation of products from by-products, and for these, mass-transfer operations are commonly used. Frequently, the separations constitute a major part of the costs of a process.

Examples for Mass Transfer Operations: Absorption, Adsorption, Distillation, Extraction, Leaching, Humidification, Drying.