Refinery continuous-time crude scheduling with consideration of long-distance pipeline transportation

• Modeling long-distance pipeline transportation with significant transfer delay and holdup.
• Integrating pipeline model with continuous-time formulation of crude scheduling.
• Implement outer-approximation based algorithm to improve solution quality.

In reality, crudes from unloading storage tanks at a docking berth may experience long-distance pipeline transportation to refinery charging tanks before their processing by crude distillation units. Such pipeline transportations cause significant transport delay and crude holdup that will substantially affect plant production performance. Unfortunately, current short-term crude scheduling studies have never systematically considered these issues. In this work, a new continuous-time crude scheduling model has been developed, which addresses the long-distance pipeline transportation and other realistic considerations such as brine settling and multiple jetties for crude unloading. The feeding of crudes into pipeline, and crude movements inside pipeline, as well as crude discharging to the receiving charging tanks are combined with the continuous time formulation of crude scheduling. The efficacy of the developed scheduling model has been demonstrated by three case studies including one industrial size example. An outer-approximation (OA) based iterative algorithm (Karuppiah et al., 2008) is implemented to successfully solve the case studies.