Electrified methane steam reforming on a washcoated SiSiC foam for low‐carbon hydrogen production

Abstract

In view of largely available renewable electricity as a green future resource, here we report the electrification of a Rh/Al 2 O 3 washcoated SiSiC foam for methane steam reforming (MSR). We show that, thanks to the suitable bulk resistivity of the SiSiC foam, its direct Joule heating up to relevant temperatures is feasible; the interconnected geometry greatly reduces heat and mass transfer limitations, which results in a highly active and energy efficient system for low-carbon H 2 production. The foam-based electrified MSR (eMSR) system showed almost full methane conversion above 700 C and methane conversions approaching equilibrium were obtained in a range of conditions. Energy efficiency as high as 61% and specific power consumption as low as 2.0 kWh/Nm 3 H 2 were measured at 650 C, at gas hourly space velocity (GHSV) of 150,000 cm 3 /h/g cat . When driven by renewable electricity, the proposed reactor configuration promises a high potential to address the decarbonization challenge in the near-term future.

Dynamic Electrification of Dry Reforming of Methane with In Situ Catalyst Regeneration

“…8 Zheng et al developed a Joule-heated steam methane reforming (SMR) reactor using a catalyst washcoated SiSiC foam with an energy efficiency of 61% and specific power consumption of 2.0 kWh/(N m 3 H2 ). 9 Chen et al demonstrated a packed monolith microwave reactor, for microwave-heated endothermic reactions, such as the dry reforming of methane (DRM), which eliminated hot spots and enabled a catalyst inventory beyond microwave adsorbing materials. 10 However, most electrification studies have been carried out under a steady state.…”

“…Electrified heating is more versatile than conventional heating. Electricity can be converted to heat via Joule heating, , microwave heating, − and induction heating. , Apart from being greener when renewable electricity is used, electrified reactors exhibit short startup times, low-temperature gradients, and cooler gases that can suppress gas-phase side reactions and lower energy use. Recently, examples of electrification have been demonstrated.…”

“…Wismann et al developed a Joule heated FeCrAl alloy tube reactor, reducing the reactor size by 100× than a current methane steam reformer . Zheng et al developed a Joule-heated steam methane reforming (SMR) reactor using a catalyst wash-coated SiSiC foam with an energy efficiency of 61% and specific power consumption of 2.0 kWh/(N m 3 H2 ) . Chen et al demonstrated a packed monolith microwave reactor, for microwave-heated endothermic reactions, such as the dry reforming of methane (DRM), which eliminated hot spots and enabled a catalyst inventory beyond microwave adsorbing materials …”

Joule-Heated Catalytic Reactors toward Decarbonization and Process Intensification: A Review

“…Moreover, the presence of coils could lead to severe heat transfer limitations. Resistance heating, however, shows high potential for such a hybrid mode operation, for example in electrified methane steam reforming configurations based on the direct Joule heating of washcoated foam catalysts inside stainless-steel tubular reactors, 73 or with the use of conductive internals combined with embedded heating elements. 60 In such cases, the stainless-steel tube reactor can be heated up easily from outside by conventional heating thus achieving hybrid operation.…”

“…The same trend was noticed also in our SiSiC foam based eMSR system electrified by resistance heating. 73 Our team at Politecnico di Milano is currently working on Joule-heated ammonia cracking, 171 with the same reactor concept already reported for methane reforming. 72,73 Instead of being washcoated on the structure, the catalyst is packed in the foam cavities: the change in the reactor configuration is due to the relatively slow reaction kinetics that call for a large catalyst inventory.…”