Optimal control in chemical engineering: Past, present and future

Roger W.H. Sargent (1926-2018) was an unprecedented pioneer who foresaw the role that mathematical and computational tools would have in chemical engineering. His visionary work created the multidisci-plinary field of Process Systems Engineering (PSE), a field that acts as a central hub influencing all sub-fields of chemical engineering. His particular interest in optimal control applied to industrial processes led him to develop numerical techniques to solve large-scale optimal control problems. In this work, a brief overview of the theory of optimal control is offered, spanning from its roots in calculus of varia-tions to Pontryagin's maximum principle and some of its extensions. Furthermore, important contribu-tions made by Sargent and his students are presented. Selected applications currently found in literature are presented as well-ranging from classical chemical engineering systems to bioprocesses. Some future perspectives of the field are also presented in the concluding section. (c) 2021 Published by Elsevier Ltd.