A Hybrid Slot-Based/General Precedence Approach for Planning Crude Oil Supplies

VANINA G. CAFARO; JAIME CERDÁ; PEDRO C. PAUTASSO; DIEGO C. CAFARO

Computer Aided Chemical Engineering

Elsevier

Año: 2017; p. 1321 - 1326

This work introducesa mixed-integer nonlinear programming (MINLP) formulation based on a hybridapproach, combining the potentials of slot-based and general precedencecontinuous-time representations. We use general precedence sequencing variablesto coordinate incoming/outgoing flows to/from every tank, and simultaneouslyaddress the scheduling of a long-distance pipeline supplying crude oil batchesfrom harbour to refinery tanks, following a slot-based scheme. The model isable to precisely monitor key component concentrations keeping oil properties withinadmissible ranges. One of the most important decisions is how to manage oilshipments so as to improve logistics efficiency. Results show that the use ofslot-based frameworks combined with general precedence variables for sequencingtasks in linking resources yields orders-of-magnitude savings in thecomputational effort to reduce costs and find optimal solutions.