Dynamic simulation of hybrid differential algebraic systems using GPROMS: case study in emulsion polymerization

This paper is deals with dynamic simulation of a semi-batch polymerization reactor for emulsion copolymerization of styrene and butyl acrylate in the presence of n-dodecyl mercaptan as chain transfer agent (CTA). Mathematical model of the polymerization reaction involved is used to predict the glass transition temperature of produced polymer, global monomer conversion, the number and weight average molecular weights, the particle size distribution and the amount of residual monomers. This model, a set of hybrid differential algebraic equations (DAEs), is implemented into gPROMS environment for modeling, simulation, and optimization

Analysis of optimal operation of a fed-batch emulsion copolymerization reactor used for production of particles with core-shell morphology

In this paper dynamic optimization of a lab-scale semi-batch emulsion copolymerization reactor for styrene and butyl acrylate in the presence of a chain transfer agent (CTA) is studied. The mathematical model of the process, previously developed and experimentally validated, is used to predict the glass transition temperature of produced polymer, the number and weight average molecular weights, the monomers global conversion, the particle size distribution, and the amount of residual monomers. The model is implemented within gPROMS environment for modeling and optimization. It is desired to compute feed rate profiles of pre-emulsioned monomers, inhibitor and CTA that will allow the production of polymer particles with prescribed core-shell morphology with high productivity. The results obtained for different operating conditions and various additional product specifications are presented. The resulting feeding profiles are analyzed from the perspective of the nature of emulsion polymerization process and some interesting conclusions are drawn

Optimal operation of batch membrane processes

This study concentrates on a general optimization of a particular class of membrane separation processes: those involving batch diafiltration. Existing practices are explained and operational improvements based on optimal control theory are suggested. The first part of the book introduces the theory of membrane processes, optimal control and dynamic optimization. Separation problems are defined and mathematical models of batch membrane processes derived. The control theory focuses on problems of dynamic optimization from a chemical-engineering point of view. Analytical and numerical methods that can be exploited to treat problems of optimal control for membrane processes are described. The second part of the text builds on this theoretical basis to establish solutions for membrane models of increasing complexity. Each chapter starts with a derivation of optimal operation and continues with case studies exemplifying various aspects of the control problems under consideration. The authors work their way from the limiting flux model through increasingly generalized models to propose a simple numerical approach to the general case of optimal operation for batch diafiltration processes. Researchers interested in the modelling of batch processes or in the potential industrial applications of optimal control theory will find this monograph a valuable source of inspiration, instruction and ideas

Design of predictive LQ controller

summary:A single variable controller is developed in the predictive control framework based upon minimisation of the LQ criterion with infinite output and control horizons. The infinite version of the predictive cost function results in better stability properties of the controller and still enables to incorporate constraints into the control design. The constrained controller consists of two parts: time-invariant nominal LQ controller and time-variant part given by Youla–Kučera parametrisation of all stabilising controllers