Hydrodynamics Modeling of a Commercial Scale Trickle Bed Reactor Using CFD

Trickle bed reactors (TBR ) are commonly used in chemical industries. Scale-up of TBR is difficult and simple scaling rules often lead to poor design. Fluid dynamics of the TBRs is complex and sensitive to the scale of the reactors. Flow mal-distribution, channeling, wetting of catalyst and local temperature variation are some of the important parameters which controls the overall performance of the TBRs. Two-phase pressure drop and liquid holdup are two important hydrodynamic parameters which should be considered while analysing and designing a TBR. By using computational fluid dynamics (CFD), we can understand fluid dynamics and its interactions with chemical reactions. In this study a CFD model has been developed for simulating two phase flow in the laboratory and commercial scales. The hydro-cracking reactor of ISOMAX unit of Tehran refinery was considered as commercial scale reactor. The CFD models were first evaluated by comparing the model predictions with the published experimental data. The models were then used to simulate the hydrodynamics of commercial scale reactor in three dimensions. Pressure drop and liquid hold up along the commercial reactor was obtained. The model will be used to understand the interaction between hydrodynamics and chemical reactions in the commercial scale reactor.

Keywords:

trickle bed , cfd , hydrodynamics , commercial scale , two phase mixture model , relative permeaility