1. Process Dynamics

A chemical process is a dynamical system, whose behavior changes over time. Control systems are needed to handle such changes in the process. Thus, it is important to understand the process dynamics when a control system is designed.

Mathematically, the process dynamics can be described by differential equations. Unsteady-state (or transient) process behavior corresponds to a situation, where (at least some) time derivatives of the differential equations are nonzero.