Dynamic Disadvantages of Intensification in Inherently Safer Process Design

The advocates of inherently safer process design have promoted “intensification” as a way to reduce the amounts of dangerous chemicals contained in a process. The idea is to design equipment to minimize the inventory of hazardous material so that the safety and environmental consequences of loss of containment are reduced in the event of a large leak from the process equipment. However, little consideration of the impact of these small holdups on the dynamic controllability of the process has been discussed in the literature. The objective of this paper is to demonstrate that intensification can sometimes adversely affect the dynamics and result in larger disturbances from normal process operation because of changes in process feed rates or conditions, process utility disturbances, or other external environmental factors. Because a “robust” process, one that can tolerate significant changes from its external environment, is also a strategy for inherently safer design, this represents an interesting confli...