Development of ceramic-based 3D staggered microchannel catalyst support used in MSR microreactor for hydrogen production

Abstract

Ceramic materials have good temperature and corrosion resistance, which is one of the ideal materials used in microchannel catalyst support for medium and high temperature catalytic reaction. Three-dimensional (3D) flow field structure is the most potential microchannel structure due to its high efficiency of mass and heat transfer. However, ceramic materials are hard and brittle, and the size of microchannel structures are small. It is a great challenge to construct a ceramic based microchannel catalyst support with a complex 3D flow field by traditional processing methods. In this paper, a 3D staggered flow field microchannel with the width of 450 μm and the depth of 1500 μm was designed and processed by diamond wire sawing. The mass and heat transfer properties of straight microchannel (SM), micro-column array (MA) and 3D staggered microchannel (3DSM) were compared by simulation. The effects of different windward angles (60°, 90° and 120°) on the performance of mass and heat transfer in 3D flow field were analyzed. The simulation results showed that the performance evaluation criteria (PEC) of 3DSM120° was 1.37, which meant better performance of heat and mass transfer than SM and MA. And the PEC of 3DSM structure was increased from 1.25 to 1.37 with the windward angle increasing from 60° to 120°. The pressure drop characteristics and hydrogen production performance of the microchannel catalyst support with different structures (SM, MA, 3DSM) were tested. The experimental results showed that the 3DSM had a good hydrogen production performance of methanol steam reforming (MSR) with the inlet flow rate of 1.5 ml/h at 300 °C. The methanol conversion rate was 99.43%, which was 15.41% and 6.20% higher than that of SM and MA, respectively, due to its better performance of mass and heat transfer.