CFD study on microchannel reactor operating conditions for Fischer-Tropsch synthesis with Fe-based catalysts.

Based on the kinetics of Fischer-Tropsch synthesis and computational fluid dynamics, this study established a numerical model for a coated microchannel reactor. The simulation results revealed the distribution characteristics of the flow fields within the reactor, demonstrating that the pressure drop in the microchannel reactor was only 3-5 Pa, with minor backmixing and potential hot spots observed near the inlet and outlet regions. Under the conditions of an inlet temperature of 340 °C, a gauge pressure of 0.7 MPa, and an H2/CO feed ratio of 2/3, the reactor with catalyst coating on both the inner and outer surfaces of the channels exhibited a maximum temperature increase of 9.1 °C and an 8.9% improvement in CO conversion compared to the reactor with only internal channel coating. The simulation results were in good agreement with experimental data, validating the accuracy of the model. The sensitivity analysis of the operating conditions revealed that inlet temperature, H2/CO feed ratio, operating pressure, and space velocity exerted distinct influences on CO conversion, maximum temperature increase, and product distribution. Lower inlet temperatures, H2/CO feed ratios, and space velocities, along with higher reaction pressures, contribute to increased C5+ yield, thereby providing a basis for the optimal design of the reactor.