0000000000411767
AUTHOR
Sami Othman
An intelligent Proportional controller of a Seeded Batch Crystallizer
Crystallization process is used in a very wide range of industrial applications. However, highly nonlinear comportment of such process and the difficulties of characterizing several phenomenological effects makes difficult to find suitable operational procedures for producing required products. In this article, we use a model-free control (MFC) for controlling the mean size of crystals produced by seeded batch cooling crystallization. The MFC method is distinguished notably in terms of the modeling strategy. Rather than developing a crystallization model within the classic population balance equation (PBE) together with the mass balance and the energy balance, as is usually done, we use a l…
Model predictive control for continuous lactide ring‐opening polymerization processes
International audience; Polylactic acid (PLA) is an attractive environment-friendly thermoplastic that is bio-sourced and biodegradable. PLA is industrially produced by the ring-opening polymerization of Lactide. This reaction is sensitive to drifts in the operating conditions and impurities in the raw materials that may affect the reaction rate as well as the polymer properties, which can be very costly in continuous processes. It is therefore crucial to employ a control strategy that allows recovering the nominal conditions and maintaining the desired properties and conversion level in case of drift. Three control strategies are discussed in this paper: Proportional-Integral controller (P…
Dynamic optimization of a continuous Lactide ring-opening polymerization process
An increasing attention has been paid to the production of the polylactic acid (PLA) in recent years, owing to its properties as a biodegradable thermoplastic besides the fact that it is derived from renewable resources. PLA is industrially produced by ring opening polymerization of lactide. This reaction is sensitive to deviations in the operating conditions that highly affect the reaction rate and the polymer properties. Therefore, a process monitoring and control policy is crucial in order to restore the nominal conditions in case of drift. In this paper, a continuous PLA process is considered with three cascade reactors, two tubular and one loop reactor, that is described by partial dif…
Estimation of the mean crystal size and the moments of the crystal size distribution in batch crystallization processes
International audience; A cascade high gain observer is designed to estimate the first four leading moments of the crystal size distribution (CSD) and the mean crystal size in batch crystallization processes. The proposed observer is based on a well-known transformation of the partial differential equation describing the CSD to a set of ordinary differential equations (the method of moments). Due to numerical difficulties resulting from the important differences in the magnitudes of the moments, a set of new variables is computed to allow a good estimation of the moments and thus the mean crystal size. In this work, only solute concentration and crystallizer temperature are used to estimate…