This interface (), found under the Chemical Species Transport branch () > Reacting Flow in Porous Media multiphysics node () >  Moving Packed Bed group node, is used to model reactors where the bed, comprised of packed porous catalytic pellets, move relative to the reactor. In addition to transport in the pore space between the pellets, intraparticle transport of chemical species and reactions are also studied.

The interparticle macropores (void between pellets), and the intraparticle micropores (pores inside the pellets) result in a system with bimodal porosity. In the Transport of Concentrated Species in Moving Packed Beds interface, the solid pellet bed is usually moving downward, counter-currently to the moving fluid between catalytic pellets.

The main feature of the interface is the Packed Bed (Moving Packed Bed) node. With the Bed Type parameter being changed from Packed bed to Moving packed bed, the Transport of Concentrated Species in Packed Beds interface switches to the Transport of Concentrated Species in Moving Packed Beds interface. For the Transport of concentrated Species in Moving Packed Beds interface, in the mass transport governing equations, there is an extra convection term from the contribution of bed moving,

For mass fraction of species i inside the reacted porous layer,