Three-dimensional evaluation of operating conditions and channel design in a wall-coated microreactor for dry reforming of methane

The impact of operational conditions and microchannel design on dry reforming of methane was evaluated in a wall-coated microreactor to improve catalytic performance. The continuity equation, momentum and energy balances, and species continuity were modeled multidimensionally, considering both catalytic and hollow zones. A response surface methodology (RSM) for the design of experiments (DOE) from CFD simulations was used for statistical modeling, optimization, and analysis of operational conditions on the H 2 /CO ratio and H 2 mass flow rate, including temperature (800–1000 °C), pressure (1–10 atm), and GHSV (80–160 L/g/h). The optimal conditions for maximizing the H 2 /CO ratio (0.953) were 4.2 atm, the highest temperature, and the lowest GHSV. The highest H 2 mass flow rate (0.912 mg/s) occurred at maximum pressure, temperature, and GHSV. Reducing microchannel size enhanced H 2 formation and increased the H 2 /CO ratio, though excessively small dimensions led to pressure losses. It has been proposed that evaluating a wide variety of microchannel designs and diameter-to-length ratios in the fixed-bed reactor under different operating conditions is necessary for a proper comparative study of catalytic performance. This research proposes efficient reactor designs. • Higher temperatures and intermediate pressure locally maximize the H 2 /CO ratio. • Higher total pressures and temperatures locally maximize the mass flow rate of H 2 . • Smaller microchannel dimensions favor both the H 2 /CO ratio and the H 2 flow rate. • Intensification in the dry reforming of methane may lead to high pressure losses. • A proper comparison between different reactors should include multiple designs.