Simulation and optimization tools in paper machine concept design

Abstract

The last decade has shown that the global paper industry needs new processes
\nand products in order to reassert its position in the industry. As the paper
\nmarkets in Western Europe and North America have stabilized, the competition
\nhas tightened. Along with the development of more cost-effective processes and
\nproducts, new process design methods are also required to break the old molds
\nand create new ideas.
\nThis thesis discusses the development of a process design methodology based
\non simulation and optimization methods. A bi-level optimization problem and a
\nsolution procedure for it are formulated and illustrated. Computational models
\nand simulation are used to illustrate the phenomena inside a real process and
\nmathematical optimization is exploited to find out the best process structures
\nand control principles for the process. Dynamic process models are used inside
\nthe bi-level optimization problem, which is assumed to be dynamic and
\nmultiobjective due to the nature of papermaking processes.
\nThe numerical experiments show that the bi-level optimization approach is
\nuseful for different kinds of problems related to process design and
\noptimization. Here, the design methodology is applied to a constrained process
\narea of a papermaking line. However, the same methodology is applicable to all
\ntypes of industrial processes, e.g., the design of biorefiners, because the
\nmethodology is totally generalized and can be easily modified.