We have studied a variety of separation processes and techniques. Our focus was on developing an elementary understanding of an individual separation process/technique. In practice, more often than not, a combination of more than one separation process is employed, regardless of the scale of operation involved. Here we introduce very briefly the separation sequences employed in a few specific industries. The separation sequences of interest are considered under the following headings: bioseparations (Section 11.1); water treatment (Section 11.2); chemical and petrochemical industries (Section 11.3); hydrometallurgical processes (Section 11.4). It is to be noted here that often the separation sequences are reinforced by chemical reactions within such a sequence or before/after the separation steps. The intent here is to provide an elementary view of the complexity and demands of practical systems where certain types of separation sequences are crucial/primary/dominant components.

More often than not, we will find that certain types of separation techniques and processes are much more prevalent in certain industries. For example, solvent extraction and back extraction processes are dominant in the recovery and purification of metals and metallic compounds via hydrometallurgical processes. On the other hand, distillation and, to a much lesser extent, absorption/stripping followed by solvent extraction are the primary separation processes in the chemical/petrochemical industries. Water treatment industries/plants are however, focused much more on deactivation/removal of biological contaminants, suspended materials and dissolved impurities from water via oxidation processes, filtration, membrane techniques and ion exchange processes. Biological separations share some of these characteristics of water treatment processes in terms of the separation techniques; however, since the focus is on recovering/purifying the biologically relevant compound, processes such as chromatography are in great demand.