Development of Microreactors for Mixing at a High Flow Rate Ratio

The present study introduces microreactors that were developed to be able to mix two kinds of raw materials at a high flow rate ratio.They consist of two substrates made of white and black polyethylene for corrosion resistance, respectively.They have a sheath flow channel that holds one raw material with the other and the channel width and depth are 0.2 or 0.5 mm. The mixing performance was evaluated using the Villarmaux-Dushman reaction, in which the flow rate ratio of the two solutions was set to 1:1, 1:5, 1:10, or 1:20. For the channel width and depth of 0.5 mm, the developed microreactor provided the same or better mixing performance than the batch method at larger total flow rates than about 2 x10(-5)m(3)/min. At a flow rate ratio of 1:20, the mixing performance of a tee connector was almost the same as that of the batch method and worse than that of the developed microreactor. For the channel width and depth of 0.2 mm, the developed microreactor provided the same or better mixing performance than the batch method at larger total flow rates than about 1 x 10(-6) m(3)/min. The mixing performance of a split-flow and interflow microreactor with four times pressure loss was worse than that of the batch method at a flow rate ratio of 1 :20. A Y-shaped microreactor with an order of magnitude larger pressure loss provided better mixing performance than the batch method at larger total flow rates than about 4x 10(-7)m(3)/min at each flow rate ratio. Therefore, the developed microreactors allow for their application to mixing in a wide range of flow rate ratios under lower pressure loss than several tens of kPa. These microreactors made of polyethylene are expected to also be used as single-use reactors, which are required particularly in the manufacturing of biopharmaceuticals.