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

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

BarcelonA

Simposio; 27th European Symposium on Computer-Aided Process Engineering (ESCAPE 27); 2017

European Federation of Chemical Engineering

This work introduces a mixed-integer nonlinear programming (MINLP) formulationbased on a hybrid approach, combining the potentials of slot-based and generalprecedence continuous-time representations. We use general precedence sequencingvariables to coordinate incoming/outgoing flows to/from every tank, and simultaneously address the scheduling of a long-distance pipeline supplying crude oil batches from harbour to refinery tanks, following a slot-based scheme. The model is able to precisely monitor key component concentrations keeping oil properties within admissible ranges. One of the most important decisions is how to manage oil shipments so as to improve logistics efficiency. Results show that the use of slot-based frameworks combined with general precedence variables for sequencing tasks in linking resources yields orders-ofmagnitude savings in the computational effort to reduce costs and find optimal solutions.