Optimal Scheduling of Multiproduct Pipelines in Networks with Reversible Flow

This paper presents a new continuous-time mixed-integer linear programming formulation for scheduling pipeline systems transporting liquid products. It is a generic formulation with respect to the structure of the network (nodes and connecting segments form the building blocks) and to the direction of flow that can change as many times as required. Nodes are connected to one or more pipeline segments, and external interactions with refineries (at a constant rate) and local markets may be included for better inventory control. To ensure a computationally efficient formulation by design, constraints with binary and continuous variables were first written as disjunction and then convex-hull reformulated. It is validated through the solution of six benchmark problems from the literature involving straight pipelines with reversible flow as well as tree-like and mesh structures with unidirectional flow. The schedules obtained by the optimization reflect, in most cases, a better utilization of the pipeline capacity.