Accelerating Batch Reactor Cycle Times
Although not a financial services company, Evonik Industries fully appreciates the time value of money. That’s especially true in terms of how the company manages the cycle time of its batch processes. A long cycle time often corresponds with erratic control. Evonik sees an opportunity for improvement through leveraging Control Station’s LOOP-PRO PID tuning technologies to improve control and to strengthen bottom-line financial performance. Evonik Jayhawk Fine Chemicals located in Galena, Kansas has successfully applied LOOP-PRO to a variety of batch processes. Where other technologies were unable to effectively model the dynamics of batch processes, LOOP-PRO – equipped with patent-pending Non-Steady State (NSS) Modeling technology – has produced quick and consistent results. With improved control and shorter cycle times, Evonik is able to improve productivity.
We maintained control by manually manipulating the control valve during the initial heat up of the reactor. We could not place the control loop in automatic until the reactor was at temperature. After tuning with LOOP-PRO we can operate the entire feed in automatic mode and, as a result, we’re seeing much faster cycle times.”
John Gaines, Senior Controls Engineer
Evonik Jayhawk Fine Chemicals
Tackling the Unique Challenges of Start-Up
The dynamics of most batch processes are tough to model during
normal operation let alone during start-up. In an effort to improve control over their batch processes, Evonik tested several prominent tuning tools. Each tool failed to accurately describe the process dynamics. Then Evonik tried LOOP-PRO.
Graphs to the left show the performance of a batch process during start-up. The “Before” image clearly shows overshoot and modest oscillation before settling out at 50° F. Settling Time for this particular loop was calculated at 133 minutes. The “After” image offers a clear contrast. Tuned using LOOP-PRO, the loop’s Settling Time was reduced to 19 minutes and produced no overshoot. In economic terms, this presented Evonik with a golden opportunity to improve control and increase the associated production profitability.
LOOP-PRO applies a unique model-fitting technology. Capable of modeling non-steady state process data, the software is altogether unique in its ability to tune batch processes that typically exhibit non-linear characteristics. It is also ideally suited for the tuning of processes at a start-up where steady-state is the desired end result. That provides a unique solution for tackling complex control issues.