Introduction Welcome to the next generation of Coulson-Richardson series of books on Chemical Engineering. I would like to convey to you all my feelings about this project which have evolved over the past 30 years, and are based on numerous conversations with Jack Richardson himself (1981 onwards until his death in 2011) and with some of the other contributors to previous editions including Tony Wardle, Ray Sinnott, Bill Wilkinson, and John Smith. So what follows here is the essence of these interactions combined with what the independent (solicited and unsolicited) reviewers had to say about this series of books on several occasions. The Coulson-Richardson series of books has served the academia, students, and working professionals extremely well since their first publication more than 50 years ago. This is a testimony to their robustness and to some extent, their timelessness. I have often heard much praise, from different parts of the world, for these volumes both for their informal and user-friendly yet authoritative style and for their extensive coverage. Therefore, there is a strong case for continuing with its present style and pedagogical approach. On the other hand, advances in our discipline in terms of new applications (energy, bio, microfluidics, nanoscale engineering, smart materials, new control strategies, and reactor configurations, for instance) are occurring so rapidly as well as in such a significant manner that it will be naive, even detrimental, to ignore them. Therefore, while we have tried to retain the basic structure of this series, the contents have been thoroughly revised. Wherever, the need was felt, the material has been updated, revised, and expanded as deemed appropriate. Therefore the reader, whether a student or a researcher or a working professional should feel confident that what is in the book is the most up-to-date, accurate, and reliable piece of information on the topic he/she is interested in. Evidently, this is a massive undertaking that cannot be managed by a single individual. Therefore, we now have a team of volume editors responsible for each volume having the individual chapters written by experts in some cases. I am most grateful to all of them for having joined us in the endeavor. Further, based on extensive deliberations and feedback from a large number of individuals, some structural changes were deemed appropriate, as detailed here. xix Introduction Due to their size, each volume has been split into two sub-volumes as follows: Volume Volume Volume Volume Volume Volume 1A: Fluid Flow 1B: Heat and Mass Transfer 2A: Particulate Technology and Processing 2B: Separation Processes 3A: Chemical Reactors 3B: Process Control Undoubtedly, the success of a project with such a vast scope and magnitude hinges on the cooperation and assistance of many individuals. In this regard, we have been extremely fortunate in working with some outstanding individuals at Butterworth-Heinemann, a few of whom deserve to be singled out: Jonathan Simpson, Fiona Geraghty, Maria Convey, and Ashlie Jackman who have taken personal interest in this project and have come to help us whenever needed, going much beyond the call of duty. Finally, this series has had a glorious past but I sincerely hope that its future will be even brighter by presenting the best possible books to the global Chemical Engineering community for the next 50 years, if not for longer. I sincerely hope that the new edition of this series will meet (if not exceed) your expectations! Lastly, a request to the readers, please continue to do the good work by letting me know if, no not if, when you spot a mistake so that these can be corrected at the first opportunity. Raj Chhabra Editor-in-Chief Kanpur, July 2017 xx