Bi-functional Ru/Ca₃Al₂O₆–CaO catalyst-CO₂ sorbent for the production of high purity hydrogen via sorption-enhanced steam methane reforming

Abstract

Sorption-enhanced steam methane reforming (SE-SMR) combines steam methane reforming and a CO2 abstraction reaction to yield high purity hydrogen.

CO2 Capture at Medium to High Temperature Using Solid Oxide-Based Sorbents: Fundamental Aspects, Mechanistic Insights, and Recent Advances

“…The catalytic performance of many bifunctional materials was shown to be excellent when only small amounts of catalyst (<5 wt %) were included. , Higher loadings are required for Ni-based catalysts if the nickel is to be oxidized and reduced cyclically, thereby adding a third functionality to the sorbent/catalyst . Taking the SE-SMR reaction as an example, NiO is reduced by CH 4 to become catalytically active Ni; the CH 4 is fully oxidized by lattice oxygen from the transition NiO → Ni, forming CO 2 and H 2 O in an endothermic reaction.…”

Simulation of Sorbent-Enhanced Steam Methane Reforming and Limestone Calcination in Dual Turbulent Fluidized Bed Reactors

“…Catalytic steam methane reforming (SMR) is the most important industrial hydrogen production route . However, the thermodynamic equilibrium of the reversible SMR reactions prevents complete feedstock conversion, thereby limiting the hydrogen production yield and purity . Previous studies have shown that in situ H 2 and CO 2 removal can favorably shift the thermodynamic equilibrium of the SMR reactions toward higher feedstock conversions. ,− In situ hydrogen removal can be achieved by inserting hydrogen perm-selective membranes (usually Pd-based) inside the reactor.…”

Low-Temperature Catalytic Dry Reforming of Methane over Pd Promoted Ni–CaO–Ca12Al14O33 Multifunctional Catalyst

“…Meanwhile, the presence of the CaCO 3 phase in the precursors was ascribed to the incompatibility of the ionic sizes of Ca and Al (0.100 vs 0.054 nm), as also reported in Ca–Al and Ni–Ca–Al HTlcs. , After calcination in the air, the precursors transformed to mixed oxides composed of NiO, CaO, and calcium aluminate phases (Figure ), due to decomposition of HTlcs and CaCO 3 and subsequent solid-state reactions . Meanwhile, the Ca­(OH) 2 phase was also detected, owing to the hydrophilic nature of CaO in the humid air . After further being reduced by H 2 at 700 °C, the reflections of the NiO phase vanished, suggesting complete NiO reduction.…”

“…37 Meanwhile, the Ca(OH) 2 phase was also detected, owing to the hydrophilic nature of CaO in the humid air. 38 After further being reduced by H 2 at 700 °C, the reflections of the NiO phase vanished, suggesting complete NiO reduction. Although Ni phases could not be distinguished in the XRD patterns of the reduced 10Ni1Pd/CaAlO as they heavily overlapped with reflections of Ca 3 Al 2 (OH) 12 phases, the H 2 -TPR profile of 10Ni1Pd/CaAlO (Figure S2) further affirmed the complete reduction of NiO, as all the reduction peaks appeared below 700 °C.…”