WARREN KENDALL LEWIS 1882-1975

BY HOYT C. HOTTEL​

Warren K. Lewis, who died on March 9, 1975, has been called the father of chemical engineering, America's number-one chemical engineer. Though his contributions both to education and to the chemical industry during a life of ninety-three years were many and solid, his hallmark was stimulation of hard thinking in others. Attack-from the head and not the heart-was Lewis' characteristic most remembered by his associates of two generations. "Doc" could bring to the solution of a problem, whether industrial or educational, a sound knowledge of physics and physical chemistry. That knowledge was well organized, his capacity for expression was superb, and his dedication to the objective of finding the answer was obvious and intense. In any discussion he loved to lecture-to students, to researchers, to industrial planners, to anyone.

Born on a farm in Laurel, Delaware, on August 21, 1882, Lewis transferred in his high school days to Newton, Massachusetts, for better schooling, and in 1901 he entered the Massachusetts Institute of Technology (MIT) and began his association with Dr. William H. Walker, Head of Chemical Engineering. On graduation he was awarded a fellowship for study in physical chemistry in Breslau, and, after receiving his Doctor of Philosophy degree in 1908, he returned to MIT as a Research Associate in Applied Chemistry. For one year he was a chemist for a tannery in New Hampshire, then returned to MIT as Assistant Professor in 1910. Having become a full Professor under Dr. Walker in 1914, Lewis was made head of MIT's Department of Chemical Engineering in 1920 when, after thirty-two years, it was finally separated from the Chemistry Department.

Dr. Lewis early recognized the need for a more unifying philosophy of education in chemical engineering and, stimulated by Arthur D. Little, worked with Walker and McAdams in identifying and quantifying what were called the unit operations of chemical industry-distillation, heat transfer, fluid flow, absorption, and so forth. In 1923 this effort produced the classic Principles of Chemical Engineering.

Dr. Lewis' other two books reflected his interest in chemical engineering education, and on applications to industrial problems. He considered combustion one of the unit operations, especially valuable in showing the student how much insight on industrial problems can be contributed by energy balances and by material balances on single chemical species. This led to publication in 1926 of a book with Radasch, Industrial Stoichiometry.

From concern with unit operations, Dr. Lewis turned to an emphasis on industrial chemical processes involving macromolecules, particularly in the areas of leather, paper, rubber, clay, textiles, and plastics. The result was a book with Squires and Broughton, The Industrial Chemistry of Colloidal and Amorphous Materials.

Dr. Lewis never failed to emphasize to his students the importance of their being able to recognize the implications to chemical industry of what they knew, and his best instruction was by example. His contributions to industry were many. A few of them follow:

Recognition of some of the implications of the alcohol industry's know-how to the oil industry, including an early improvement in vacuum distillation of lubricating oils; responsibility for the first large-scale application of continuous rectification in the petroleum industry; the upgrading of shell stills by superimposing rectifying columns; contributions to improved quantification of multicomponent distillation.

In the rubber industry, contributions to the structure of macromolecules and to improved understanding of the kinetics of vulcanization; a course of instruction to a rubber research group on applied physical chemistry.

Major aid in bringing coke deposition in thermal cracking of petroleum under control, through identification of the kinetics of thermal cracking. He recognized the importance of eliminating hold-up in processing equipment, of allowing for the contribution, to the deposition of coke, of higher-than-first-order polymerization processes occurring in two-phase flow.

In oil-field recovery problems, work on two-phase flow through porous media, on high-pressure p-v-T relations for hydrocarbons, on interphase equilibrium constants.

Fluidized-bed catalytic cracking. Dr. Lewis was a pioneer in the study of fluidization of comminuted solids, in the application of fluidization to catalytic cracking, a process replacing fixed-bed operation in which loss of catalyst activity through carbon deposition and difficulty in temperature control during regeneration by carbon burn-off had been major problems. The present capital investment in fluidized-bed processes is in billions of dollars.

Space has not permitted adequate elaboration of these few of many contributions made by Dr. Lewis to chemical industry. His performance both as an educator and as a practicing engineer was recognized by many honors and awards, listed here:
Honorary Doctorate Degrees-University of Delaware, Princeton University, Harvard University, Bowdoin College
President's Medal of Merit
President's Medal of Science
Perkins Medal of the Society of Chemical Industry
Lamme Medal of ASEE
Establishment of AIChE'S Warren K. Lewis Award
Priestly Medal of the American Chemical Society
Gold Medal of the American Institute of Chemists
New England Award of the Engineering Societies of New England Industrial and Engineering Chemistry Award of the ACS
American Petroleum Institute Gold Medal for Distinguished Achievement Founder's Award of the American Institute of Chemical Engineers
John Fritz Medal of five national engineering societies
Establishment at MIT of the Warren K. Lewis
Professorship in Chemical Engineering

Warren Kendal Lewis would have been proud to know that by now twenty- seven of his former students have become members of the National Academy of Engineering. Perhaps the best closing tribute to him is a quote from an article written, when he was still vigorous at eighty-eight, by his former student he admired most, Edwin R. Gilliland: The characteristics that made Dr. Lewis outstanding as a teacher and builder of men were a tireless devotion to his work and to his ideals, a rare form of modesty in giving credit to others, sympathy for the man who made an effort (excellence preferred, but the effort was paramount), a wonderful enthusiasm for his profession and for tackling the tough problems, for making chemical engineering practice a vivid and colorful experience, and a knack for teaching and for inspiring the best in his students and associates.