Design of Microreactor Flow Channel for Fischer Tropsch Synthesis Using Computational Fluid Dynamic

AbstractIn this work, the numerical model was used to investigate the effect of microchannel geometries including channel aspect ratio and cross-sectional area of a microreactor for Fischer – Tropsch reaction performance. The comparative study was based on 20%Co-0.5%Re/γ-Al2O3 catalyst, a space time in a range of 0.0020 – 0.0060 gcat·min/N·cm3 and Reynolds number lower than 1. The base case model was set as a square cross-sectional area with a dimension of 0.7 mm×0.7mm and a length of 20mm. It gave 22.41% of CO conversion. The simulation results showed that changing of aspect ratio induced a little effect to reaction performance. The maximum conversion difference was 7.90% resulted from the most shallow flow channel of 1.225mm × 0.175mm compared to the base case model. When increasing microchannel cross-sectional area to 1.00mm × 1.00mm, it gave negative effect on Fischer – Tropsch reaction performance, while reducing the cross-sectional area, to a 0.300mm × 0.300mm with the length of 50.18mm, it gave higher CO conversion and higher pressure drop when compared to other cases. Minimum channel length obtained from different cross-sectional area of microchannel were studied. The smaller cross-sectional area the shorter channel length was required. In this work, systematic analysis and interpretation of microchannel for FTS design were achieved