In the coming decades, our society will be confronted with enormous global challenges that include energy transition, climate change, health care, and scarcity of materials, food, and water. The chemical and related process industries present an important element of those grand societal challenges, in particular regarding materials and energy efficiency, environmental burden, and operational safety. Process intensification (PI), aiming at substantial increase in the material and energy efficiency, improved safety, and environment‐friendly processing, presents one of the most promising ways of dealing with those challenges and is commonly seen as an important progress area in chemical and process engineering.

This book has come into being as a result of c. 15 years of experience in teaching Process Intensification at MSc level in Delft University of Technology, the Netherlands, and in the University of Leuven, Belgium. It presents a different approach to PI than the ones seen in the numerous books published on that topic so far. Here, we try to explain Process Intensification in a more fundamental way, through four generic principles and four elementary domains: spatial, thermodynamic, functional, and temporal. As the result of such an approach, the vision on PI becomes broader than the traditional one. We go beyond the usual PI methods and equipment aimed to remove the limitations in heat and mass transfer or mixing. We look, among other things, into manipulating the molecules or even atoms, in order to improve the reaction kinetics, or into eliminating the randomness in the systems, in order to even out the processing experience of the molecules. We discuss the mechanisms of the interactions between various energy forms and materials, we look for the synergies at different process levels, and we analyze the ways of manipulating the time characteristics of the events.

The book consists of three parts. In the first part, we present a short history of Process Intensification and discuss the development of its definitions and interpretations (Chapter 1). The generic principles of Process Intensification are introduced in Chapter 2. Part II consists of four chapters, each dedicated to one of the four elementary domains addressed by PI. In the spatial domain (Chapter 3), various forms of structures targeting different phenomena at different scales are discussed. Chapter 4 (thermodynamic domain) focuses on the use of alternative forms and transfer mechanisms of energy in processing systems. In the functional domain (Chapter 5), we examine the possibilities of combining various functions within one processing step or one apparatus, in order to achieve synergistic effects. Finally, in Chapter 6, various aspects of Process Intensification in the temporal domain, such as manipulation of characteristic times of events or introduction of dynamic elements, are discussed. The third, final part of the book (Chapters 7 and 8) focuses on the practical implications of Process Intensification for sustainability. It discusses the methods for ecological assessment of PI technologies and the effects of PI on the inherent process safety. It also presents an approach to the conceptual design of an intensified chemical plant, illustrated with the example of a case study that the MSc students in Delft and in Leuven do every year, namely the PI‐based conceptual redesign of the Union Carbide's carbaryl process in Bhopal, once the place of the worst technological disaster in the history of mankind.

Although the present book is primarily aimed as the support in the postgraduate‐level teaching of Process Intensification, we believe that a considerable part of the material presented here will also be of interest to engineers working in industry. This includes not only the chemical processing sector, the birthplace of PI, but also other industrial sectors where the word EFFICIENCY is the name of the game.

The preparation of this book has been a long and complex process and we would like to express our sincere gratitude to Keerthivasan Rajamani for the immense editorial work on the text and the images and to Florens Kruik for providing numerous graphics for the book.

Andrzej Stankiewicz: Full Professor and Chair of Process Intensification at Delft University of Technology, the Netherlands, and Director of TU Delft Process Technology Institute. With almost 40 years of industrial and academic research experience, he is the author of numerous scientific publications on Process Intensification, chemical reaction engineering, and industrial catalysis. Prof. Stankiewicz is one of the pioneers of Process Intensification. He is the principal author and co‐editor of the world's first book on Process Intensification. The book was translated to Chinese in 2012. Prof. Stankiewicz is also the author of the first full‐size academic course on Process Intensification.

Prof. Stankiewicz is the Editor of Chemical Engineering and Processing: Process Intensification (Elsevier) and the Series Editor of the Green Chemistry Books Series (Royal Society of Chemistry). He was the founder and first Chairman of the Working Party on Process Intensification at the European Federation of Chemical Engineering. He currently chairs the Board of the European Process Intensification Centre (EUROPIC).

Current research interests of Prof. Stankiewicz focus on control of molecular interactions and intensification of chemical reactions using electricity‐based energy fields (e.g. laser, microwave, and UV). The research in that area has brought him prestigious Advanced Investigator Grant from the European Research Council. More recently, Prof. Stankiewicz has initiated and coordinates the H2020 “ADREM” project on methane valorization using alternative forms of energy in modular catalytic reactors.

Tom Van Gerven: Professor of Process Intensification at the University of Leuven, Belgium, and head of the Process Engineering for Sustainable Systems section in the same university. He is the author of numerous publications on Process Intensification, solid waste treatment, and sustainable processing. He focuses on the use of ultrasound and light for efficient chemical processing. Since 2013, he is the chairman of the Working Party on Process Intensification at the European Federation of Chemical Engineering. In 2019, he chaired the second International Process Intensification Conference (IPIC2) in Leuven, Belgium.

Georgios Stefanidis: Professor at the University of Leuven. He holds a Diploma in Chemical Engineering from the National Technical University of Athens and a PhD degree in the same field from the University of Gent. He has co‐authored numerous publications in the broad field of Process Intensification, mostly focusing on alternative energy forms and transfer mechanisms (mainly microwaves and plasma). In the area of plasma processing, he received, among other things, a prestigious grant from the Bill and Melinda Gates Foundation. He is currently the Associate Editor of the Chemical Engineering and Processing: Process Intensification Journal (Elsevier), Vice Chair of the EFCE Working Party on Process Intensification, and serves in the management board of the Association of Microwave Power in Europe for Research and Education (AMPERE).