Transparent silicon/glass microreactor for high-pressure and high-temperature reactions

To increase mass transfer in solid catalyzed gas-liquid hydrogenations, the reactions are often operated at high pressures. Silicon/glass microreactors present a possibility to safely handle high-pressure and provide optical access into the reaction channel for flow investigations. In this study we present a Si/glass microreactor with soldered microfluidic connections for high-pressure and high-temperature applications. Mechanical testing of the device by tensile and pressure tests showed no failure for continuous operation at 140 bar and 80 degrees C. The improved microreactor design is applied for a well-described solid catalyzed exothermic hydrogenation at operating conditions up to 51 bar and 71 degrees C. Additionally the two-phase gas-liquid flow is investigated in the microreactor. Results clearly indicated the improvement of the reaction rate from 0.004 mol g(cat)(-1) min(-1) at ambient conditions to 0.046 mol g(cat)(-1) min(-1) at 51 bar and 71 degrees C. The reaction was observed to be mass transfer limited. (c) 2007 Elsevier B.V. All rights reserved.