In the present work novel microstructures are developed and studied by means of analytical and numerical methods. These microstructures form part of a demonstration microdevice to carry out a distillation without chemical reaction, two for the liquid and gaseous phase distribution/collection, and one for the liquid/gas mass transfer (“μTU-I,-II”). A solution for the 3D velocity field for the velocity component w in flow direction can be given for the rectangular and semicircular microchannel by using a lubrication approximation which gives good realistic values for the Reynolds number at low flow rates comparing to the common 2D approaches. The μTU-I is studied using the CFD code (6.3 FLUENT ® - 3ddp) by the approach of the VOF model. The simulations are performed with the test system methanol/water (distillation). By varying the flow rates of both phases and the contact angle, the condition until the occurrence of flooding of the microunit “μTU-I” is determined. The flooding and the optimum operating conditions of a new optimized configuration “μTU-II” -microunit are also investigated by means of numerical simulation (CFD). It can be shown that longitudinal instability is generated. Based on several concepts for liquid and gaseous phase distribution/collection by the Forschungszentrum Karlsruhe, novel microstructures (“Liquid-Distribution-Collection-Microstructure”, “Vapor-Distribution-Collection-Microstructure”) for both phases are developed, studied and optimized by using CFD. The results of all studies are verified based on the demonstration device in the laboratory.

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