Dosage of Filter Aids in the Case of Pure Surface Filtration - An Optimal Control Approach

Filter-aid filtration is widely used to remove impurities which tend to clog the filter medium. In many processes, filter aid is continuously dosed to the suspension to be purified. In these cases, a suitable filter-aid concentration is important to assure good separation with a minimal energy consumption. We here present the first optimal control approach to filter-aid filtration. The optimal dosage trajectories in case of constant and variable impurity concentrations in the suspension are derived for the case of pure surface filtration. These findings are compared to other dosage strategies and the benefits are shown. Consequences of the presented results for process control and further modeling and optimization approaches are highlighted.