Rigorous formulation for the scheduling of reversible-flow multiproduct pipelines

• We propose a continuous-time approach for scheduling reversible-flow pipelines.
• The model allows to change the flow direction as many times as needed.
• We seek to minimize pumping, interface, setup and inventory carrying costs.
• Input/output schedules at pipeline extremes and intermediate depots are generated.
• Optimal schedules for real world case studies are found in low CPU times.

Pipelines play a major role in the petroleum industry by providing a safe, reliable and economical transportation mode over land. Frequently, they connect a pair of refineries or harbors with the purpose of sharing oil products. As the construction of twin pipelines transporting products in opposite directions demands large capital investments, reversible-flow pipelines arise as a promising alternative. This paper introduces a novel continuous-time formulation for the short-term operational planning of reversible multiproduct pipelines. The proposed model allows to change the flow direction as many times as needed to meet terminal demands, determining precise time instants for flow reversals. It provides the input and output schedules in a single step, and the most convenient product used as filler to push current batches out of the line. Three examples are successfully solved with much less computational effort than previous approaches.