This chapter aims to clarify the concept of population balance model or population balance equation, terms that are used almost interchangeably in this book. This is followed by a short narrative of the strengths and weaknesses of these models. What Are Population Balance Models? Population balance is not a well-defined concept in science and engineering, but means slightly different things to different people. During the fall of 2004, a Web search on the term “population balance model” gave more than 1 million hits, and a casual perusal of some of the Web pages obtained in this search makes.
