Optimal control of crystallization of alpha-lactose monohydrate

We present a mathematical model for solvated crystallization of a-lactose monohydrate in semi-batch mode. The process dynamics are governed by conservation laws including population, molar and energy balance equations. We present and discuss the model and then control the process with the goal to privilege the production of small particles in the range between 10^-5 and 10^-4μm. We compare several specific and unspecific cost functions leading to optimal strategies with significantly different effects on product quality. Control inputs are temperature, feed rate, and the choice of an appropriate crystal seed.