Criterion for stability of steady states and its prediction in a fluid catalytic cracker.

Abstract

Necessary and sufficient conditions for existence of steady states are derived from a mathematical model of fluid catalytic cracker (FCC), and sufficient conditions for stable steady states are determined from the Hurwitz stability criterion by using a linearized FCC model. Based on the graphical analysis of these conditions in a three-dimensional coordinate, a criterion for stability and multiplicity of steady states is developed. By applying the criterion to three kinds of chemical reaction types in the FCC, the stability of steady states can be successfully predicted under various operating conditions.