Packed bed reactors have been widely used in the chemical and process industry for several decades. They can be difficult to design and operate due to their size and complexity. Therefore, there is still room for improvement of the performance of these reactors and rigorous simulations can help here to achieve desired goals with lower upfront investment. Recent advances in modeling particle-resolved packed beds allows a detailed inside in the flow, species and temperature distribution in the beds and therefore also into the conversion of the surface reactions. Based on these simulations, model parameters for 1D-models can be estimated. These 1-D models can then be used to calculate performance of multi-tubular reactors, either by running a computationally expensive simulation with resolved tubes or by coupling the CFD simulation to an advanced process modeling tool like gPROMS. In the latter case, the flow non-uniformity as well as certain flow properties like coolant velocity and temperature is taken from the CFD simulations, while on the process modeling side heat transfer and reactions in the packed bed are calculated based on the simplified 1D models. This modeling approach is fully 2-way coupled and highly efficient in terms of accuracy and especially runtime and it can be embedded into a flow sheet simulation.
In this contribution, we will present the whole simulation process and how the different steps intertwine with each other starting from the detailed particle resolved simulation all the way down to the flow sheet simulation. The benefit of this approach will be demonstrated based on several examples.