Modelling and simulation of a single slit micro packed bed reactor for methanol synthesis

A mathematical model for a single slit packed microstructured reactor-heat exchanger in the synthesis of methanol from syngas was developed. The model constitutes a simplified 3D-pseudo homogeneous approach for a reaction slit with integrated pillar geometry. Literature kinetic rate expressions for methanol synthesis over commercial Cu/ZnO/support type catalysts were applied at 80 bar total pressure, temperature range of 473-558 K, and syngas composition of H2/CO/CO2/N2:65/25/5/5 mol%. The model is found capable of predicting experimental CO conversion data with acceptable accuracy. Superior thermal stability of the microchannel upon variation of different parameters such as contact time, feed gas temperature and reaction temperature were shown. The simulation results also reveal that the microchannel reactor can operate free of performance loss due to concentrations field that may arise from overlaid temperature fields. Simulations have also been used to calculate the rapid temperature transients at the inlet. The agreement between simulation results and experimental data signifies the applicability of the developed model for further design and performance optimization of microstructured reactors for methanol synthesis and other exothermic processes.