Intensified sorption-enhanced ethanol reforming for syngas production through utilization of reforming-derived CO2

Bimetallic NiM/Al-CaO catalysts (M = Co, Cu) were investigated for their performance in sorption-enhanced steam reforming (SESR) and sorption-enhanced autothermal reforming (SEATR) of ethanol for high-purity H 2 production. Following SESR and SEATR, the sorbent regeneration step was designed to favor the reverse water–gas shift (rWGS) reaction, enabling the conversion of the released CO 2 into syngas. After 20 consecutive redox–carbonation cycles, Ni/Al-CaO and NiCo/Al-CaO exhibited comparable CO 2 capture capacities of 0.28 and 0.22 g CO 2 per g CaO, respectively. In contrast, NiCu/Al-CaO displayed lower performance (0.18 g CO 2 /g CaO). NiCu/Al-CaO showed the formation of a dense Ca 2 CuO 3 phase that decreases the available surface area and promotes CaO crystallite growth. Catalytic testing showed that both Ni and NiCo formulations sustained average H 2 yields above 93% with stable breakthrough times of approximately 14 min. Notably, the NiCo/Al-CaO catalyst demonstrated superior activity in the rWGS step, achieving 87% CO 2 conversion and 97% selectivity toward CO. Overall, the NiCo/Al-CaO catalyst emerges as the most promising candidate for integrated hydrogen production and CO 2 utilization, offering enhanced reactivity, stable cycling behaviour, and improved process efficiency, thereby strengthening the viability of this approach for sustainable energy applications.