Intensifying steam methane reforming and water-gas shift in tandem via rapid pulsed Joule heating

• Rapid pulse heating (RPH) of steam methane reforming is studied. • RPH improves efficiency by leveraging high and low-temperatures. • RPH enhances reforming rates and H 2 productivity with low power input. • High steam/carbon ratios and elevated pressures maximize benefits. • RPH intensifies processing by integrating multiple reactors in the temporal domain. Steam methane reforming (SMR) is the primary industrial method for syngas (a mixture of carbon monoxide (CO) and hydrogen (H 2 )) and H 2 production. SMR is one of the most carbon-intensive processes. Due to the ineffectiveness of the water-gas shift (WGS) reaction at the high SMR temperatures, high-purity H 2 requires two downstream WGS reactors. This study demonstrates how dynamic Joule heating can intensify SMR and WGS in a single reactor, boosting H 2 yield. We show that rapid pulsing drives methane conversion and H 2 /CO ratios beyond steady-state limits, mostly at higher pressures and steam-rich feeds through thermodynamic analysis, transient kinetic modeling, and experiments. Our simulations highlight the role of pulse shape in maximizing both conversion and H 2 /CO ratios leveraging high- and low-temperature regimes. Experimental results confirm that pulsed heating is more efficient than conventional and steady-state heating, maximizing H 2 productivity and reforming rates. These findings position rapid pulsed Joule heating as an intensifying approach to integrate high-temperature endothermic and low-temperature exothermic, equilibrium-limited reactions.