Plant-wide optimization and control of an industrial diesel hydro-processing plant

• Published in: Computers & chemical engineering Vol. 87; pp. 234 - 245
• Main Authors: Aydın, Erdal, Arkun, Yaman, Is, Gamze, Mutlu, Mustafa, Dikbas, Mine
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 06.04.2016
• Subjects: Blending; Chemical engineering; Diesel; Diesel fuels; Diesel properties; Empirical modeling; Fractionation; Hydro-desulfurization reactors; Industrial plants; Mathematical models; Model predictive control; Optimization; Refineries; Sulfur removal; Model predictive control; Sulfur removal; Blending; Diesel properties; Hydro-desulfurization reactors; Empirical modeling
• ISSN: 0098-1354; 1873-4375
• DOI: 10.1016/j.compchemeng.2016.01.016

•Empirical models to predict sulfur content of the feed, D86 curve of the feed and T95 value of the diesel product are developed.•A cascaded MPC structure is used to implement the results of economic plant wide steady-state optimization.•Supervisory MPC computes the optimal set-point trajectories for FeedT95 and the exit temperatures of the reactor beds.•Local regulatory MPCs are designed to track the set-points supplied by the Supervisory MPC.•Simulations show that desired sulfur removal is achieved and the product Diesel meets its end properties in an economically optimal and safe operation. Diesel hydro-processing (DHP) is an important refinery process which removes the undesired sulfur from the oil feedstock followed by hydro-cracking and fractionation to obtain diesel with desired properties. The DHP plant operates with varying feed-stocks. Also, changing market conditions have significant effects on the diesel product specifications. In the presence of such a dynamic environment, the DHP plant has to run in the most profitable and safe way and satisfy the product requirements. In this study, we propose a hierarchical, cascaded model predictive control structure to be used for real-time optimization of an industrial DHP plant.