Model optimization for the dynamic simulation of reactive absorption processes

The optimal design of reactive separations is impossible without reliable process models. Especially for the dynamic simulation and the model-based control of complex reactive absorption processes the model development leads to a contradiction between the required model accuracy to reflect the process complexity and the feasibility of process simulations regarding the computation time. In this respect, we have developed a new rigorous dynamic two-phase model based on the two-film theory as a first step, which takes into account the influence of chemical reactions and additional driving forces in electrolyte systems on mass transfer considering thermodynamic nonidealities as well as the impact of column internals on the process hydrodynamics. For a model optimization, we have performed an analysis of different model approaches for complicated industrial absorption processes and determined an appropriate model complexity. Based on results of sensitivity studies, we have accomplished different model modifications leading to a stabilization of the numerical solution without affecting the good agreement between simulation results and the experimental data. This time-optimized model can be considered superior as compared to previous approaches and facilitates for the first time a rigorous dynamic simulation of entire reactive absorption columns and the application within an on-line process control system.