Micro-fiber elements as perfusive catalysts or in catalytic mixers: Flow, mixing and mass transfer

The flow, mixing and mass transfer in a catalytic stirrer containing catalyst coated porous micro-fiber elements, based on a concept introduced by Moulijn, were studied in a lab-scale reactor with 13 samples of materials with fiber diameters from 8 to 35 μm and porosity values between 0.60 and 0.90. Pressure drop in these sintered metallic fiber materials was shown to follow a modified Kozeny–Carman equation: View the MathML sourceΔPL=2+0.053ε1−ε3μ16df2(1−ε)2ε3u0 Turn MathJax on When rotating in the reactor, the flow through the fiber mats can be estimated from View the MathML sourceu−1=τL=32μLαDρdf22(1−ε)2ε3+0.053(1−ε)uT−2 Turn MathJax on where αD is a drag coefficient of around 2.5. Flow through the catalyst in an operational stirrer can be adjusted over several orders of magnitude by manipulating parameters, such as rotational speed, dimension of the fiber stack and its material characteristics. Mass transport between fibers and the liquid flow through fiber stacks follows: ε⁡Sh=0.47Re1/2Sc1/3ε⁡Sh=0.47Re1/2Sc1/3 Turn MathJax on