(308a) A Century of Transport: a Personal Tour

The industrial chemists and mechanical engineers who banded together in 1908 to form the AIChE were self-taught experts in the design and operation of equipment to carry out chemical processing. Although graduates with a degree in chemical engineering had been entering industry for over a decade, none of them were among the founding members because they failed to meet the qualification of “years of responsible charge”. The skills possessed by the founding members can be discerned from the early identification of chemical engineering with what we now call the unit operations. Remarkably, these unit operations were all physical and did not invoke chemical reactions explicitly.

These first chemical engineers were distinguishable from chemists, other than perhaps “industrial” ones, by their utilization of continuous processing and thereby of an Eulerian rather than a Lagrangian framework for modeling, as well as by their involvement with transport, in particular with fluid flow, heat transfer, and mass transfer. The work of chemical engineers was distinguishable from that of mechanical engineers by virtue of their involvement with chemical conversions and chemical separations, and over the century with an increasing variety of materials, many of them synthetic and new to the world. Accordingly, the differences in the approach of chemical engineers and mechanical engineers to fluid mechanics, heat transfer, and thermodynamics have continued to widen. The joint designation of fluid mechanics, heat transfer, and mass transfer as transport rather than as unit operations,and rather than as separate topics, began with the publication in 1960 of the most influential book in the history of chemical engineering, namely Transport Phenomena by Bob Bird, Warren Stewart, and Ed Lightfoot. Unfortunately, the added topics in fluid mechanics and the shift to transport phenomena in the curriculum have come at the price of poorer and poorer preparation for our students in basic fluid mechanics and heat transfer.

My objective today is to review the evolution of the skills and practices of chemical engineers in dealing with transport, avoiding those aspects being addressed by the other speakers. Although our understanding of transport has evolved over the century and the applications have expanded, this subject now has a lesser role in education and practice because of competition in the academic program from new topics such as biotechnology and nanotechnology, although they themselves involve transport.