Implementation of MPC on a Deethanizer at Kårstø Gas Plant

Abstract

Model predictive control (MPC) is implemented on several distillation columns at the Kårstø gas processing plant, Norway. The paper describes the procedure in the implementation of MPC at a deethanizer using the SEPTIC * MPC tool, including design, estimator development, model development and tuning. For the deethanizer, the variance in the product quality has been reduced with about 50%. The number of flaring episodes has also been reduced. An increase in impurities has not been challenged yet, so the average reflux flow and steam consumption to feed ratios are almost unaltered.

Coordinator MPC for maximizing plant throughput

“…The local MPC applications are built with experimental step response models as described in Aske, Strand, and Skogestad (2005). The prediction horizon is 3-6 h, which is significantly longer than the closed-loop response time.…”

Robust model predictive control of a pilot plant distillation column

“…Since the early days of MPC technology, conventional MPC has been applied to distillation systems mainly in oil refineries (Richalet, 1993;Hovd, Michaelsen, & Montin, 1997;Minh & Muhamad, 2010;Porfírio & Odloak, 2011) and petrochemical plants (Gokhale, Hurowitz, & Riggs, 1995;Huang & Riggs, 2002;Aske, Strand, & Skogestad, 2005, 2006. In these applications, it was realized that distillation columns are nonlinear systems and the conventional linear MPC may have a poor performance if the distillation column needs to operate at different operating conditions.…”

Coordinator MPC for maximizing plant throughput

“…The local MPC applications are built with experimental step response models as described in Aske et al (2005). The prediction horizon is 3 to 6 hours, which is significantly longer than the closed-loop response time.…”