Packed-Bed Reactor Characterization of Steam-Regenerated Solvent Adsorbers for Raw-Gas Cleaning

Paper in proceeding, 2017

Packed beds with activated carbon is a commonly used technology for removing unwanted substances from a process stream. To better understand how such beds operate and in order to optimize their design and operation, one-dimensional models are typically employed. The multiphase aspects of these systems are typically neglected due to their complexity, even though regeneration with steam creates a liquid phase that may trickle through the bed, thereby effectively transporting heat and mass. This paper investigates and characterizes the differences in transport of gas and liquid in a representative packed bed through comprehensive three-dimensional numerical simulations. In addition, the effect of heterogeneities in the packing of the bed on the transport of both phases is also investigated. It is confirmed that the dispersion of air may be well described by a conventional one- dimensional model, but that the dispersion of water requires an additional effort. It is also found that the system orientation significantly influences the water flow and that non-ideal packing has strong effects on the residence time distribution for both phases.