Fluidic Catalytic Cracking Power Recovery Dynamic Computer Simulation

Abstract

Fluidic Cat Crackers (FCC) using the catalyst regeneration cycle are candidates for more power efficient operation by the use of high temperature dirty gas expanders. In a previous paper, a computer simulation was described for the steady state operation of the primary mechanical components, specifically the axial compressor and hot gas expander. The present work expands upon the steady state model to add the dynamic characteristics of these elements as well as the effects of the controlling process valves. In many applications the expander will develop more power than the axial compressor can absorb. A power absorbing source, specifically an electrical generator, converts the mechanical excess power into electrical energy. A review of the mechanical equipment and the electrical generator operating modes and controls is needed so that the process designer and operator will know how the system will respond if process upsets were to occur. The program code developed can simulate these elements for specific processes and demonstrate the logic control scheme proposed by the process designer. This information will therefore allow the process operator, process designer and mechanical equipment supplier an understanding of the interplay of the system control elements and define specific operating limits.