Application of Simulation Models in Operations – A Success Story

Process simulation models can offer significant capabilities for operating personnel to analyze and troubleshoot current performance and to develop optimum responses in a proactive manner. This can increase agility in decision making, improve reliability and lower operating cost. Historically, only engineers have had the knowledge of how to utilize these process models. Limited engineering resources and lack of offshift availability can limit a model’s effectiveness. To more fully realize these benefits, operating personnel need an easy-to-use interface driven by robust and reliable simulation models. This paper discusses the best practices of using simulation models in operations, and demonstrates how new developments in modeling technologies can help. The Valero Paulsboro Refinery has applied its crude unit simulation model for operational troubleshooting, analysis and optimization. This paper outlines the challenges and opportunities of using this model. It also illustrates the use of Aspen Simulation Workbook (ASW) to develop a Microsoft Excel based user-friendly interface to link high fidelity simulation models with the data historian tags, and to automate the complex workflow. In addition, it demonstrates how the Aspen HYSYS model was upgraded to an advanced model using Aspen RefSYS to provide a robust model that has been used to evaluate over 10 different crude assays and track petroleum properties (e.g. Sulfur, Conradson Carbon, API, etc) of the products. Aspen RefSYS simplifies the use of pseudo components in crude assay characterization and improves the convergence of atmospheric and vacuum columns.