Application of a Large Predictive Multivariable Controller to a Hydrocracker Second Stage Reactor

The installation of a large constrained multivariable controller on the second stage reactor of Suncor's hydrocracker unit has been completed. The control problem is complex and required an unusual controller structure to allow it to be solved with the computing resources available. The performance of the controller has been good, and has resulted in much more stable and consistent control of the whole hydrocracker complex. The controllers ability to operate the unit at its constraints provides significant economic benefits when the capacity of the unit is limiting.