Process systems engineering: from solvay to the 21^st century. A history of development, successes and prospects for the future

The term Process Systems Engineering (PSE) is relatively recent, but the engineering of processing systems is as old as the beginning of the chemical industry, around the beginning of the 19^th century. Initially, the practice of PSE was informal and as time went on it was formalized in progressively increasing degrees. Today, it is solidly founded on engineering sciences and an array of systems theoretical methodologies and approaches. This paper provides an overview of the history of Process Systems Engineering (PSE), i.e. its origin and evolution, a brief illustration of its tremendous accomplishments in the development of modern chemical industry, and an outline of the role it can play in addressing the societal problems that we face today; securing sustainable production of chemicals and materials for the human wellbeing, alternative energy sources, improving the quality of life and of our living environment. Finally, this paper proposes PSE as the foundational underpinning of modern chemical engineering; the only one that ensures the discipline's cohesiveness in the years to come.