Crude oil scheduling in refinery operations

Abstract

Scheduling is one of the tools that facilitates refiner to be proactive for changing scenarios and allows finding solutions that generate enhanced income. Scheduling considerations prevalent with crude oil operations in a petroleum refinery have been addressed in this work. Scheduling of crude oil operations is part of optimization of overall refinery operations and involves unloading crude oil from vessels to storage tanks and charging various mixes of crude oils from tanks to each distillation unit subject to capacity, flow, and composition limitations. Refinery configurations with different unloading facilities such as SBM (Single Buoy Mooring), multiple jetties are considered in this study. Scheduling of crude oil operations is a complex nonlinear problem, especially when tanks hold crude mixes. A novel iterative MILP solution approach for optimizing crude oil operations is devised which obviates the need for solving MINLP. This work addresses both discrete and continuous time scheduling models for crude oil scheduling problem and presents a head to head comparison of the two models. The proposed methodology performs much better in comparison to methodologies present in the literature and gives near optimum solutions, thus making them suitable for large-scale operations.