energy-efficient optimal control of crude distillation columns using proportional-integral-plus (pip) framework: a simulation-based approach

Objective: the objective of this research is to optimize the crude distillation unit (cdu) in oil refineries by reducing energy consumption and improving operational efficiency through the application of a proportional-integral-plus (pip) control system within a non-minimal state space (nmss) framework. material and method: simulations of the cdu were carried out using aspen plus for modeling the distillation process and matlab for implementing the pip control structure. the controller was tuned by an economic cost function, optimizing key parameters such as furnace duty, side-draw rates, and condenser heat removal. the pip control system was compared to traditional control methods, with performance evaluated under various disturbances, including feed rate, temperature, and composition changes. results: the pip control strategy significantly improved the cdu’s performance, reducing operating costs by up to 100% compared to traditional control methods optimized by the integral of time-weighted absolute error (itae). the pip system demonstrated superior disturbance handling and energy efficiency while maintaining product quality. conclusion: the findings indicate that the pip control system is a highly effective tool for optimizing energy consumption and process stability in modern refineries, especially under fluctuating operational conditions. its application could lead to substantial cost savings and improved efficiency in cdu operations.