%0 Journal Article
%T Averaging Level Control to Reduce Off-Spec Material in a Continuous Pharmaceutical Pilot Plant
%A Richard Lakerveld
%A Brahim Benyahia
%A Patrick L. Heider
%A Haitao Zhang
%A Richard D. Braatz
%A Paul I. Barton
%J Processes
%D 2013
%I MDPI AG
%R 10.3390/pr1030330
%X The judicious use of buffering capacity is important in the development of future continuous pharmaceutical manufacturing processes. The potential benefits are investigated of using optimal-averaging level control for tanks that have buffering capacity for a section of a continuous pharmaceutical pilot plant involving two crystallizers, a combined filtration and washing stage and a buffer tank. A closed-loop dynamic model is utilized to represent the experimental operation, with the relevant model parameters and initial conditions estimated from experimental data that contained a significant disturbance and a change in setpoint of a concentration control loop. The performance of conventional proportional-integral (PI) level controllers is compared with optimal-averaging level controllers. The aim is to reduce the production of off-spec material in a tubular reactor by minimizing the variations in the outlet flow rate of its upstream buffer tank. The results show a distinct difference in behavior, with the optimal-averaging level controllers strongly outperforming the PI controllers. In general, the results stress the importance of dynamic process modeling for the design of future continuous pharmaceutical processes.
%K control
%K process modeling
%K process simulation
%K parameter estimation
%K dynamic modeling
%K optimization
%K crystallization
%K continuous pharmaceutical manufacturing
%U http://www.mdpi.com/2227-9717/1/3/330