The area of separations is extremely broad. Most separation processes/techniques have an extensive literature. Each process has its own universe. Yet there are a few common principles and characteristics that are shared by many separation techniques/processes. This book has provided an elementary introduction to such principles and characteristics, even as it provides some details of many of the most commonly used separation processes. It is hoped that this book will help the reader to be prepared to undertake more extensive studies of individual processes/techniques or of a certain class of techniques or certain sequences of separation processes/techniques.

An important goal of this book is to develop an appreciation that separation processes/techniques may be understood on the basis of a few key features/concepts: the nature of the force causing the selective movement of molecules, macromolecules and particles; the nature of the various regions/phases in the separation system; the four types of bulk flow pattern of the regions/phases vis-à-vis the direction(s) of the forces causing selective movement of species/particles to be separated; the method of feed introduction. Further, for relatively simple systems, one could develop the governing equations that describe the separation achievable from the set of basic governing equations provided in Section 6.2 for most systems described in the book. In addition, a useful introduction to the role played by chemical reactions of certain types for a variety of separations has been provided.