Judson King, Chemical Engineering, University of California, Berkeley, South Hall Annex #4650, Berkeley, CA 94720-4650
The first great unifying concept of chemical engineering was that of unit operations, put forward by Arthur D. Little and colleagues in the early part of the twentieth century. Many of the unit operations were, in fact, separation processes. With the Manhattan Project, unifying aspects of these different methods of separation came to be recognized, and in the decades immediately following World War II were developed and codified so as to create disciplinary underpinnings for separations as a distinct field of knowledge. The history of that transition is traced, and a number of the unifying concepts of separations are identified. These concepts enable more efficient and powerful approaches to selection, design, improvement and comparison of separation processes. There are many disciplinary approaches for pertinent elements of the sciences underlying chemical engineering, but there are few for actual engineering activities. Separations is one such area. Finally, a number of current major separations needs provide vivid examples of why the education of chemical engineers needs to be substantially broadened.