Module 8. CSTR

Unlike many of the other modules, this module is too lengthy to be performed in a single 1- to 2-hour session. Each instructor or reader is likely to have a different focus. Much of the initial material is related to modeling and interesting nonlinear aspects. If the focus is on controller design, the initial material can be skimmed before Problem M8.4 is completed. After studying this module the reader should be able to understand:

• The effect of scale-up on the steady-state and dynamic characteristics of a jacketed chemical reactor. Further, understand how these characteristics affect the control system design and operating performance.

• These reactors can have input-output operating curves that are nonlinear; that is, the "process gain" is not constant.

• Larger reactors have a reduced capability of removing heat compared to smaller reactors. Often, a larger reactor is operated at an unstable point, while the smaller reactor (with the same residence time) is stable.

The major sections of this module are

M8.1 Background

M8.2 Simplified Modeling Equations

M8.3 Example Chemical Process—Propylene Glycol Production

M8.4 Effect of Reactor Scale

M8.5 Further Study: Detailed Model

M8.6 Other Considerations

M8.9 Summary