Optimization of hydrogen supply distribution in addition to new hydroprocessing unit

Tighter environmental legislation across the globe pushes refineries to produce more cleaner fuel. This restriction is more impactful to developing nations, like Indonesia, struggling to meet newer fuel specifications. The cleaner fuel production requires more hydrogen, which will increase the need for a new hydroprocessing unit. Hence, optimizing hydrogen supply distribution in the refinery is essential considering the new hydroprocessing unit. The system of hydrogen supply distribution itself has complicated constraints, such as flow rate, hydrogen purity, and pressure, which need to be satisfied. Therefore, the mathematical programming approach, which includes a non-linear programming model (NLM) and mixed-integer non-linear programming model (MINLM), is used. To satisfy hydrogen demand, maximizing the flow rate of the new hydroprocessing unit without increasing hydrogen utility capacity is set as the objective function. Those methods are applied to hypothetical cases based on literature, and the results are compared between NLM and MINLM. The results show that both methods can generate the same result. However, MINLP is favored for its ability to construct superstructures automatically.