A Mixed-Integer Linear Programming Model for Optimizing the Scheduling and Assignment of Tank Farm Operations

Abstract

This paper presents a novel mixed-integer linear programming (MILP) formulation for the tank farm operation problem (TFOP), which involves the simultaneous scheduling of continuous multiproduct processing lines and the assignment of dedicated storage tanks to finished products. The objective of the problem is to minimize blocking of the finished lines by obtaining an optimal schedule and an optimal allocation of storage resources. The novelty of this work is the integration of a tank assignment problem with a scheduling problem where a dedicated storage tank has to be chosen from a tank farm given the volumes, sequencing, and timing of production of a series of products. The scheduling part of the model is based on the multioperation sequencing (MOS) model by Mouret et al. (Mouret, S.; Grossmann, I. E.; Pestiaux, P. Time representations and mathematical models for process scheduling problems. Comput. Chem. Eng.2011, 35, 1038–1063). The formulation is tested in three examples of different size and complexity.