Steam Methane Reforming (SMR)

Description

This lesson covers a CFD simulation of Steam Methane Reforming (SMR), the industrial process most widely used to produce hydrogen from hydrocarbon feedstock. In an SMR reactor, methane reacts with steam over a catalyst through a set of endothermic reactions to yield hydrogen, carbon monoxide, and carbon dioxide, with the heat these reactions require supplied externally by a burner in a surrounding heating chamber. The project models a sleeve-type SMR reactor, capturing both the catalytic reforming chemistry inside the tubes and the combustion process that drives it, making this a genuinely coupled, multi-physics chemical engineering problem rather than a single-mechanism simulation. The plant geometry, comprising the heating chamber and reforming tubes together, is built in Design Modeler and meshed with a large unstructured grid of roughly 1.65 million elements to resolve the multiple reacting zones.

Methodology

Because several chemical species, H2, CO, CO2, CH4, and O2, need to be tracked simultaneously, the Species Transport model is used to solve a transport equation for each. Chemistry is introduced through multiple volumetric reactions: three reforming reactions inside the tubes and a separate combustion reaction in the heating chamber, so the two reacting zones are handled with distinct reaction sets appropriate to their chemistry. The catalyst inside the reforming tubes is represented as a porous medium, coupling the reacting flow directly to porous-zone momentum losses, and since the reforming reactions are endothermic, the heat exchange between the burner and the reforming tubes is modeled explicitly to sustain the reaction.

Analysis

Results are read through mass fraction contours for each species, which trace methane being consumed and hydrogen being produced as the reacting mixture moves through the tubes. These contours let you confirm the reactor is behaving as intended: reforming reactions progressing appropriately along the tube length and heat transfer from the combustion chamber sustaining the endothermic reactions rather than allowing them to stall. More broadly, the combination of multi-reaction Species Transport with a catalytic porous zone demonstrated here is directly transferable to catalytic converters, other fuel reformers, and combustion systems across the process industries, since the underlying coupling between reacting flow and porous catalytic media is the same problem in each case.