Computers & Chemical Engineering, Vol.128, 77-87, 2019
Integrated optimal design and scheduling for a bitumen upgrader facility
Partial upgrading of bitumen is advantageous yet energy intensive in itself, needing various resources such as electricity, heat, hydrogen, and steam. Therefore, partially upgrading the bitumen while minimizing energy usage and thus lowering the carbon footprint is desirable. Consequently, optimal design and operation of an upgrader then becomes a challenging two-pronged problem. The key, however, lies in identifying that the design and operation problems are not mutually exclusive, but instead, synergistic, and hence require simultaneous consideration. Consequently, this research highlights the importance of the real-time integrated design and scheduling problem through two formulations; maximizing profit and minimizing energy usage. The results indicate changes in design and scheduling decision variables as per the medium-term forecasts of the volatile commodity and energy pricing markets. Therefore, a design independent of the scheduling constraints or a schedule based on a fixed design may lead to suboptimal results in the design and/or schedule decision space(s). (C) 2019 Elsevier Ltd. All rights reserved.
Keywords:Mixed integer nonlinear program (MINLP);Optimal design;Optimal schedule;Profit maximization;Energy minimization;Partial bitumen upgrading