Design of a Ratio Control Algorithm for a Fluid Catalytic Cracking System in an Universal Oil Product Context

Abstract

This paper delves into the intricate dynamics of industrial fluid catalytic cracking, a pivotal process in refining universal oil products (UOP). At the core of this investigation is the endeavor to derive a comprehensive mathematical model that captures the essence of mass and energy balances within a UOP fluid catalytic cracking unit. The study's central objective is to explore and apply a ratio control algorithm in two distinct operational scenarios. In the first scenario, the ratio controller is strategically positioned after the control valve for the regenerator's input air, while in the second, it precedes the control valve. The primary focus here is the meticulous control of outlet temperatures for both the riser and regenerator reactors. Leveraging the capabilities of MATLAB software, the research methodically simulates the fluid catalytic cracking process. It introduces variables such as the gas oil feed rate, along with the temperatures of the gas oil feed and air, to rigorously test the efficacy of the proposed ratio control algorithm. The results of this investigation reveal a notable superiority of the ratio control in case one over case two. In the riser and regenerator reactors, this advantage is demonstrated by improved stability and operational efficiency, as evidenced by lower integral absolute error (IAE) readings and a quicker approach to the intended setpoint temperatures.