Before starting his graduate degree at
MIT, Thiele worked for six months for Swift and Company in Chicago and later in Baltimore as a process analyst, before being employed with Peoples Gas Light and Coke Company as a chemical engineer from 1920 to 1922. After completing his doctoral thesis on steam-carbon reactions, he developed (jointly with
McCabe) a graphical method of design for fractionating (i.e.,
distillation) columns as a transformational publication in
Industrial and Engineering Chemistry in 1925. This approach to the design of distillation columns was rapidly adopted in undergraduate textbooks and has remained the traditional approach to teaching distillation to undergraduate chemical engineers for almost a century. Thiele joined the
Standard Oil Company of Indiana (then
Amoco, now
BP) as a chemical engineer in 1925. He continued with this company for 35 years becoming an assistant director for research in 1935 and associate director for research in 1950. During the period of
World War II, he contributed to numerous technologies related to nuclear materials processing and atomic energy including a heavy water extraction facility, the Lexington Project for the design of nuclear-powered aircraft, and as a consultant to the Congressional Joint Committee on Atomic Energy. During 35 years at Standard Oil, Thiele exhibited remarkable creativity and produced 17 landmark publications, and 27 U.S. patents that served as the foundation of chemical engineering. Classic engineering papers include his breakthrough paper on the efficient design of distillation systems via computational methods with co-author R.L. Geddes published in 1933 in
Industrial and Engineering Chemistry. Further work led to the development of
solvent extraction of lubricating oils. Another landmark contribution was the 1939
Industrial & Engineering Chemistry paper that described the
Thiele modulus, a
dimensionless quantity describing the boundary between reaction-controlled and transport-controlled catalytic particles. Following retirement from Standard Oil, Thiele became a professor of chemical engineering at Notre Dame where he taught courses in thermodynamics, reactions, instrumentation, process control, and simulation. Following 10 years at Notre Dame, Thiele returned to Chicago and lived the next 27 years in the Skokie-Evanston area. Thiele died November 29, 1993, in the Presbyterian Home in Evanston. == Honors ==