Fluid dynamics in microchannel reactors

The possible benefits of using microchannel reactors in the chemical proces s industries have been under discussion for several years. Outstanding heat transfer properties, short residence times and short diffusion lengths are considered key advantages, while the cost of the approach and the pending question of long-term stability are still major sources of skepticism. A go od starting point for a feasibility study is to investigate some major flui d dynamic properties. For a unit consisting of hundreds of parallel microch annels, the pressure drop for the laminar flow is just a few millibar. Howe ver, at high gas flows the distribution over the numerous channels may beco me non uniform. It is shown how the resulting residence time distribution a ffects both the yield of intermediates in consecutive reactions, and step f unctions of the concentration during periodic operation, respectively. All in all, the results of the estimations are encouraging.