Dynamic real-time optimization maximizes the efficiency of your production
Alexandre Boriouchkine / 19 Feb 2018
The future will make everything around us increasingly complex, be it cars, electronics or household items. If we compare cars from thirty years ago to their modern counterparts, the outsides have a strong resemblance – but on the inside they couldn’t be more different.
The same aspects, namely improving environmental awareness and continuously tightening competition have increased the complexity of industrial plants. At the same time, the ability to maintain these plants at maximum economic efficiency is becoming increasingly challenging. This has created continuous demand for tools to improve the economic and operational performance of industrial plants.
One such tool which is widely used in the industry is the Real-Time Optimization (RTO). RTO has, over the years, successfully increased operational efficiency of numerous process sites. The operation principle of RTO is to find optimal setpoints for a local advanced process or other type of a multivariate controller, so that the overall economic efficiency of the plant is maximized. The plant must be allowed to reach a steady-state before the next round of optimization run can be performed.
Reaching steady-state in a relevant time period is, however, not always possible. The large size of modern plants, combined with slow process dynamics, presence of recirculation flows and transportation delays, all pose their own complications. As a result, echoes of past events can still disturb a plant for hours after their actual occurrence. Additional changes to setpoints and disturbances in, for example, feed composition might increase this time period even further.
In such situations, DRTO has to be employed in order to ensure the optimality of process operation. Due to its dynamic nature, DRTO does not require steady-state conditions and will optimize the economic performance of the plant even whilst the process is undergoing changes. Furthermore, DRTO can utilize this additional dynamic degree of freedom to handle setpoint transitions and product grade changes through economically optimal trajectories.
Thus, DRTO can also ensure that a minimal amount of off-spec product and pollution is created during product grade transitions, which can otherwise result in large quantities if the product grade switches occur frequently.
The NAPCON Improve category includes both an advanced process controller, NAPCON Controller and DRTO, NAPCON Optimizer. The DRTO has also been successfully applied to a petrochemical plant. The Borealis ethylene cracker in Porvoo achieved a long-term profit increase of over 100 million USD through utilization of NAPCON DRTO.
At NAPCON, we are especially proud of this achievement. We believe that through helping our clients improve the efficiency and competitiveness of their plants, we can achieve a long lasting positive impact in the world around us.
A special thank you to Jussi Mäkilä, our optimization and advanced process control expert, for the feedback during writing of this blog.
DSc. Alexandre Boriouchkine