A mathematical model for scheduling of real-world tree-structured multi-product pipeline system

In this paper, a mathematical model to petroleum derivatives transportation scheduling is developed. The problem discussed in this paper is concerned with the scheduling of one-source tree-structured pipeline connected to several output terminals. A tree-structured pipeline is composed of a mainline conveying high-volume of petroleum products over long ways and secondary lines transporting smaller volumes over shorter distances. In such a pipeline, batches of petroleum products are pumped back-to-back at the origin of the mainline, without any separation device between them. This paper introduces a continuous mathematical representation, mixed integer linear programming, for the operational planning of tree-structured pipeline systems. Previous contributions on tree-structured pipeline planning deal with the sequence deliveries at receiving terminals, i.e., at any time only a unique terminal receives material from the pipeline. On the contrary, the proposed approach permits a receiving terminal on the mainline to simultaneously receive products when one of the secondary lines is taking material from the mainline. The problem's aim is to find the optimal sequences of product injection and dispatching operations that satisfy product demands at minimum total cost, accounting for pumping and backordered demand costs during the specified planning horizon. The approach has been validated by solving three case studies of growing complexity.