Development of Al-stabilized CaO–nickel hybrid sorbent–catalyst for sorption-enhanced steam methane reforming

High temperature CO2 sorbents and their application for hydrogen production by sorption enhanced steam reforming process

“…Besides a physical admixture of catalyst with sorbent, hybrid catalyst-sorbent patterns which integrate the catalytic reaction and the CO 2 sorption in a single pellet can present some advantages such as the elimination of mass diffusional limitation and the reduction of reactor volume [197,198]. Several studies have been performed on the development of hybrid catalyst-sorbent materials for SESMR process [199][200][201][202][203][204][205]. A first attempt to combine CaO-based sorbent and catalyst in a single pellet was performed by Martavaltzi and Lemonidou [201] who developed a hybrid Ni- …”

“…It was also found that the presence of a high Ni loading (10 wt.%) caused Ni self-agglomeration. Radfarnia and Iliuta[204] developed NiO-CaO/Ca 9 Al 6 O 18 hybrid catalyst-sorbent materials with various nickel loading(12,18, and 25 wt.% NiO) via a simple wet-mixing method (limestone acidification coupled with two-step calcination technique) and investigated their application in SESMR operation (S/C of 4, 650°C and 1 bar). According to the experimental results, the best performance belonged to the hybrid material containing 25 wt.% NiO, which showed an average H 2 production efficiency of 96.1 % during 10 cycles (180 min reaction per cycle).…”

Improving the stability of synthetic CaO-based CO 2 sorbents by structural promoters

“…Several theoretical [36,37] and experimental [38][39][40][41][42][43] studies on reforming of different fuels combined with CO 2 capture have shown that the addition of the CO 2 sorbent in the reformer shifts the equilibrium of the global reaction to the products' side, leading to increased H 2 efficiency and a CO 2 stream ready for sequestration in a single step, while operating at lower temperature than the conventional processes. In the case where methane is used as a fuel, the process is called sorption enhanced steam methane reforming (SE-SMR) and it takes place according to reactions (2)- (4).…”

Catalytic performance of Ni/CaO-Ca 5 Al 6 O 14 bifunctional catalyst extrudate in sorption-enhanced steam methane reforming

“…Unfortunately, the catalyst is in the form of powder, which makes it of little practical use. In fact, most CaO-based bifunctional catalysts prepared to date are small unshaped powders [30][31][32][33][34][35][36], with the exception of those reported by Wheelock et al [28,29]. They prepared corein-shell spherical pellets (with an average diameter of 4.5 mm), consisting of a lime or dolomite core and an alumina shell onto which nickel was deposited.…”

“…However, a major challenge to be solved is the stability of catalyst. So far, some CaO-based bifunctional catalysts have been prepared for the SESMR process [28][29][30][31][32][33][34][35], but most of them suffer from poor stability, i.e., the catalyst stability is decreased with the number of reforming-regeneration cycles. Very recently, a Ca 5 Al 6 O 14 -stablized Ni/CaO catalyst prepared in our group [36] equilibrium was reached using this type of catalyst.…”