An optimization model for site-wide scheduling of coupled production plants with an application to the ammonia network of a petrochemical site

Abstract

This contribution presents the modeling and optimization of the operation of production plants that are coupled via distribution networks and applies it to a part of the petrochemical production site of INEOS in Köln in Germany. The problem is formulated as a mixed-integer linear problem and solved to generate an optimal monthly plan for a set of plants, tanks, and loading/unloading facilities, while respecting various constraints arising from technical limitations, physical couplings between the plants, production targets, and the schedule for import and export across the company borders via ships and trains. The optimization problem takes into account varying energy prices, the influence of the ambient temperature on the processes, and the inventory management for different types of storages. We solve the optimization problem for the particular case and compare the results for a 1 month scenario to recorded data and show that a significant energy saving potential exists. We discuss the current limitations and outline potential improvements in the context of the application of the optimization model to optimal site planning that leads to an improved coordination of the production in the process industries.

A preface to the special issue on enterprise-wide optimization

“…The authors apply their method on a real-life industrial case study and report considerable savings in total costs as well as reductions in land usage. 1 Wenzel et al (2019) study the operation of production plants that are coupled via distribution networks, formulating an MILP that accounts for inventory coupling and uncertainties in energy 1 3…”

Integrating Continuous and Batch Processes with Shared Resources in Closed-Loop Scheduling: A Case Study on Tuna Cannery

“…However, if resource consumption is not constant over time, the obtained solutions are conservative, which results in unnecessarily longer completion times, lower productivity, and limited manufacturing flexibility. In these cases, continuous process dynamics need to be integrated somehow into the scheduling formulation. , However, processes often obey some nonlinear principles that would lead to complex non-convex optimization problems without optimality guarantees. While this limitation can be affordable in a real-time (static) optimization framework, it is not computationally viable for online scheduling problems.…”

“…In these cases, continuous process dynamics need to be integrated somehow into the scheduling formulation. 15,16 However, processes often obey some nonlinear principles that would lead to complex non-convex optimization problems without optimality guarantees. While this limitation can be affordable in a real-time (static) optimization framework, 17 it is not computationally viable for online scheduling problems.…”

Optimal Design of Sustainable Ammonia-Based Food–Energy–Water Systems with Nitrogen Management

“…It is crucial that the design of such a plant also takes operational aspects into account. The majority of existing studies on optimizing sustainable ammonia systems consider either design − or scheduling with significantly fewer addressing both. Allman et al consider the scheduling-informed optimal design of a wind-powered ammonia system by replacing the set of detailed operational constraints with a data-driven surrogate model in the overall design problem.…”