FCC unit reactor-regenerator control

Abstract A fluid catalytic cracking (FCC) unit offers a unique challenge to control engineers by virtue of its complex process dynamics and because of the conflict between its operating constraints and its economic objectives. This communication shows how these two issues were addressed in a multivariable control strategy, which was implemented with the IDCOM-M controller on the FCC unit in a European refinery. The communication also presents and discusses the dynamic process models identified from open-loop step test data. The discussions of the process models and of the control strategy are both illustrated with trends of actual process data.