He is known for his highly impactful work in chemical reaction engineering, complex reacting systems, and separations, including distillation theory.

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.

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.

[4] 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.

[6] 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.

Ernest Thiele has authored numerous journal articles describing significant advances in chemical reaction engineering which includes but is not limited to: