Sorption enhanced steam reforming of ethanol over Ni-based catalyst coupling with high-performance CaO pellets

Coupling with the conventional Ni/Al2O3 catalyst, novel CaO-based porous spherical sorbents (made by a new molding technique) were examined in the sorption enhanced steam reforming of ethanol process (SESRE) to improve the H-2 quality. The cyclic H-2 quality was monitored, and the catalytic properties of the catalyst for steam reforming of ethanol as well as the CO2 capture capacity of the modeled sorbents were studied in details. Besides, thermodynamic modelling has been done by Gibbs free energy minimization method to simulate the sorption enhancing effect and screen the optimized reaction conditions to yield high-quality H-2; furthermore, the relative H2O consumption versus ethanol during the reforming process was further discussed. The results showed that the sorption enhanced steam reforming process was an effective and flexible way to produce high-quality H-2 around 600 degrees C, and subsequently the simulated sorption enhanced process was validated experimentally. In addition, the properties of the catalyst and modeled sorbents were analyzed by N-2 physisorption, SEM, EDS-Mapping, H-2-TPR, XRD, Raman, In-situ DRIFTS and so on. A high purity H-2 was yielded during the pre-breakthrough stages, in especial that process enhanced by the modeled sorbents templated by cellules (CaOS-C5 pellets), which illustrated a good prospect of SESRE process. With the CaOS-C5 pellets, during the 10th SESRE process, H-2 could be constantly produced with purity above 90% within at least 15 min of SESRE process. The modeled CaO spheres greatly boosted the concentration and output of H-2. Over the repeated cycles, the Ni/Al2O3 catalyst and the modeled sorbents displayed well stability over the long-term reactions, which illustrated a good prospect of SESRE process enhanced by these new spherical sorbents.

Automated summary

The study successfully improved the quality of H-2 gas produced during the sorption enhanced steam reforming (SESRE) process of ethanol by coupling novel CaO-based porous spherical sorbents with conventional Ni/Al2O3 catalyst. The results showed that the sorption enhanced steam reforming process is an effective and flexible way to produce high-quality H-2 around 600 degrees C, and the simulated sorption enhanced process was experimentally validated.