To achieve the desired crystal size distribution (CSD) for the cooling crystallization process of β form L-glutamic acid (LGA)

the population balance equation (PBE) of size-dependent growth rate was established by using the method of characteristics (MOCH)

and then the optimal supersaturation and temperature curves during the crystallization process were determined by parameter estimation for the established PBM. Due to the nonlinearity and non-convexity of the objective function for model parameter identification

a small number of economic batch crystallization experiments were conducted in combination with image analysis on the crystal seeds and product shapes

in order to fit the model parameters. According to the practically required cycling time for crystallization

to realize the target CSD

the optimal curve of decreasing temperature was determined by optimizing the supersaturation curve of the crystallization process

so as to implement the control of crystal growth process based on the maintained supersaturation level. Experiment results showed that the desired CSD could be achieved by implementing the optimal supersaturation control scheme via the optimized temperature control curve.