Supply chain optimization of large-scale continuous processes

In this work, a supply chain model for a petrochemical complex is formulated as a multiperiod mixed integer nonlinear program (MINLP). The model includes production, product delivery, inventory management and decisions such as individual production levels for each product, as well as operating conditions for each plant in the complex. Two multiperiod MINLP are formulated in order to compare models with different levels of rigorousness. The first one includes linear mathematical models derived for the ethylene plants while the second considers semi-rigorous nonlinear models. Simplified models based on rigorous existing models tuned with actual plant data are considered for the natural gas plants, taking into account variations in production with key plant operating variables. Data for chemical transformations and utilities consumption from the literature have been used to model the remaining plants.