A numerical investigation of hydrogen production in an integrated membrane reformer-combustor

Membrane-based steam methane reforming technique is one of the most promising technologies for hydrogen production. In this work, we carried out performance analysis of hydrogen production in an integrated membrane reformer-combustor (IMR-C) under industrial relevant reformer pressure and gas hourly space velocity (GHSV). A detailed computation fluid dynamics (CFD) was used to model the IMR-C that comprises: steam methane reforming zone, combustion zone and hydrogen permeate zone. Hydrogen (H₂) yields are generally observed to increase with increasing reformer pressure and decreasing GHSV. Operating conditions such as lower reformer pressure and higher GHSV that decreases the hydrogen yield simultaneously increases carbon monoxide (CO) emissions in the combustion zone. This is due to the fact that un-permeated H₂ compete with the produced CO (that is slowly burning) for oxygen in the combustion zone. Operating conditions such as high pressures and/or low GHSV that favour high hydrogen yield will also favour low CO emission. This is due to the fact that less H₂ would compete with CO for the available oxygen in the combustion zone.