Dynamic and Steady State Simulation of Coke Oven Gas Purification

The purification of coke oven gas represents a complex multicomponent separation process combined with many parallel reversible chemical reactions. For the theoretical description of this process, traditional equilibrium stage models and efficiency approaches are usually inadequate. Therefore, a rigorous dynamic two-phase model based on the two-film theory has been developed, which takes into account diffusional interactions, the influence of chemical reactions on mass transfer, thermodynamic non-idealities and the impact of structured packings and liquid distributors on the process hydrodynamics. In addition, the influence of driving forces in electrolyte systems like electrical potential gradients are considered. This rigorous dynamic rate-based approach leads to a system of algebraic and differential equations, which has to be solved numerically. For the H2S scrubber, steady- state and dynamic simulation results are presented. The model validation and the determination of parameters require steady-state and dynamic experiments, which have been carried out in a pilot-scale gas scrubber, equipped with a process control system. The simulation results are in good agreement with the experimental data and hence, the developed dynamic model serves as a basis for the model-based control.