INTRODUCTION
The major objective of this book is to learn how to design equipment for carrying out desirable chemical reactions. The design and operation of such equipment, that is, reactors, requires rates of both physical and chemical processes. The principles governing such physical processes as energy transfer and mass transfer are often as important as those which govern chemical kinetics. This combination of physical and chemical operations is also a distinguishing feature of chemical engineering; the design of chemical reactors is an activity unique to the chemical engineer.
To design a reactor means to answer the following questions: What type and size of equipment are needed to accomplish the desired extent of reaction? What operating conditions (temperatures, pressures, flow rates) are required? What provisions are necessary for exchange of energy (usually as heat) with the sur- roundings? The answers to these questions constitute the process design of the reactor. A cost analysis to determine the most profitable design introduces further questions about construction materials, corrosion, utility requirements, and main- tenance. In order to maximize profits, the instrumentation and a control policy (ranging from manual to closed-loop computer control) for optimuni operation should be determined. Optimum design will also depend indirectly on estimates of such market conditions as the price-volume relationships for reactants and prod- ucts. While these factors are important in overall design and operation of reac- tors, they will not be discussed in this book. Our use of the term design will be restricted to process design.