Methane steam reforming in a microchannel reactor for GTL intensification: A computational fluid dynamics simulation study

摘要

The integration of the steam reforming and combustion of methane in a catalytic microchannel reactor has been simulated by computational fluid dynamics (CFD). Two models including 4 or 20 square microchannels of 20 mm of length and 0.7 mm of side have been developed. It has been assumed that a thin and homogeneous layer of an appropriate catalyst has been uniformly deposited onto the channels walls. The kinetics of the steam reforming of methane (SRM), water-gas shift (WGS) and methane combustion in air have been incorporated into the models. This has allowed simulating the effect of the gas streams space velocities, catalyst load, steam-to-carbon (S/C) ratio and flow arrangement on the microreformer performance. The results obtained illustrate the potential of microreactors for process intensification: complete combustion of methane is achieved at gas hourly space velocities (GHSV) as high as 130,000 h~(-1). As concerns the SRM, methane conversions above 97% can be obtained at high GHSV of 30,000 h~(-1) and temperatures of 900-950 ℃. Under these conditions selectivity for syngas is controlled by the WGS equilibrium.