Challenges in start-up control of a heat exchange reactor with exothermic reactions; a hybrid approach

In this paper, the control of a continuous heat exchange reactor is investigated from a hybrid perspective with focus on the start-up phase and the transition to the optimal operating point. The temperature sensitive exothermic reaction leads to the possibility of multiple steady states and in combination with safety constraints forms an interesting challenge for a safe and efficient start-up. A series of MPC controllers are developed with a switching logic that transfers the process from initial rest to continuous optimal operation mode. The control procedure is verified in simulations with a full nonlinear model of the Open Plate Reactor, an improved heat exchange reactor being developed by Alfa Laval AB. The case study can be seen as a benchmark problem for start-up control of exothermic reactions