(195g) Integrated Refinery Planning and Utility Operations for Optimal Energy and Emissions Management

The increasing awareness of the impact of production processes in our environment has led to the search for better ways to include sustainability considerations in the decision-making process. Including other indicators in the process of designing, evaluating, and optimizing processes implies the need to consider models that better reflect the behavior of the systems and that can capture the sustainability dimension of the problem. In this work, we present the integration of detailed utility plant models in the optimization of crude oil refinery planning to account for a better energy consumption estimation, emissions evaluation, and environmental footprint reduction. This work integrates two different leading modeling paradigms in the industry (both from Aspen Technology, Aspen Unified PIMS^TM and Aspen Utilities Planner^TM, respectively). A realistic refinery planning model is developed and integrated with a detailed model for a typical refinery utilities plant (both for the Gulf Coast area of the US). The combined mathematical model is optimized (maximizing profit) while accounting for the detailed power and steam generation requirements and the associated emissions. The optimal solution of the combined model indicates a non-trivial change to the optimal crude slate (compared to the traditional simple utilities representation) due to the more detailed utilities modeling and the increasing sustainability considerations. In addition to the base case, a set of emissions reduction scenarios are considered (using both emission-reduction incentives as well as regulatory constraints). The results show the implications in planning decisions that are derived as restrictions on emissions are considered. In conclusion, the enhanced modeling of the utilities plant in the refining and petrochemical industries allows a better representation of internal energy consumption due to utilities generation and more information on energy utilization. Ultimately, this methodology leads to more informed and beneficial decisions that impact both sustainability and profitability considerations.