An Integrated Mathematical Model for Scheduling Multiproduct Pipeline Networks

DIEGO C. CAFARO, JAIME CERDÁ

Buenos Aires, Argentina

Congreso; Congreso Interamericano de Ingeniería Química; 2006

AAIQ - CIIQ (Confederación Interamericana de Ingeniería Química)

Abstract. Scheduling product batches in pipelines is a very complex task with many constraints to be considered.  Several papers have been published on the subject during the last decade. However, all model-based scheduling techniques were applied to examples assuming a static market environment, short time horizons and a unique due-date for all deliveries at the horizon end. Pipeline operators generally use a monthly planning horizon divided into a number of equal-length periods and a delivery cyclic schedule periodically repeatedly injecting the same sequence of batches to fulfill product demands at period ends. Moreover, variations in product requirements at distribution terminals with time and shipment rerouting force the scheduler to continuously update pipeline operations. To overcome such drawbacks of current approaches, this work presents an efficient MILP continuous-time framework for the dynamic scheduling of pipelines over a multiperiod moving horizon. Pumping runs may extend over two or more periods and a different sequence of batches may be injected at each one. The approach has successfully solved a real-world pipeline scheduling problem involving the transportation of four products to five destinations over a rolling horizon always comprising four one-week periods. Some heuristic and model-based tools to generate the detailed pipeline schedule at the operational level are also presented.