Kinetic modelling of an industrial semi-batch alkoxylation reactor for control studies

Semi-batch processes are gaining further importance in the chemical industry, due to the trend to produce more speciality products with higher margins. Besides a constantly high product quality, a maximum space-time-yield is a principal goal of process control for semi-batch processes. This requires to drive the process along its limits, which often is impossible with standard PID control schemes. More sophisticated control methodologies potentially allow for a maximisation of the space-time-yield while keeping the product quality high. However the scientific development and test of such methodologies is often conducted using very simplified reactor models, which may allow for a demonstration of the basic feasibility but neglect additional effects, which hamper the transfer to industrial processes. Therefore a more detailed model of a semi-batch process, suitable for the development and test of control schemes is presented in this contribution. Using this model, a simulation study elucidates the limitations of classical temperature control concepts when aiming for a maximisation of the space-time-yield.