Sorption enhanced steam reforming of ethanol on Ni–CaO–Al2O3 multifunctional catalysts derived from hydrotalcite-like compounds

Abstract

This paper describes the sorption of carbon dioxide for enhanced steam reforming of ethanol to produce hydrogen via Ni-CaO-Al 2 O 3 multifunctional catalysts derived from hydrotalcite-like compounds (HTlcs). The catalysts were characterized by N 2 adsorption-desorption, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), H 2 temperature-programmed reduction (H 2 -TPR) and thermogravimetric analysis (TGA) and tested in sorption enhanced steam reforming of ethanol (SESRE), in which products were monitored by an online mass spectrometer (MS). The Ni-CaO-Al 2 O 3 catalysts possess uniform distribution of Ni, Ca and Al, contributing significantly to the excellent CO 2 adsorbent capacity and reforming activity in SESRE. We have also examined the effect of Ca/Al ratios on Ni dispersion, CaO particle size, and catalytic reactivity; a Ca/Al of 3.0 was optimized. The Ni-CaO-Al 2 O 3 catalysts outperform the conventional mixture of CaO adsorbents and Ni/Al 2 O 3 catalysts for SESRE. CH 3 CH 2 OH + 3H 2 O 4 2CO 2 + 6H 2 , DH r,298 K ¼ 173 kJ mol À1 (1) CO + H 2 O 4 CO 2 + H 2 , DH r,298 K ¼ À41 kJ mol À1 (2) CaO (S) + CO 2 4 CaCO 3(S) , DH r,298 K ¼ À178 kJ mol À1 (3)

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

“…Apart from post-combustion CO 2 capture, in-situ carbonate looping has also been investigated as means of process intensification in thermodynamically limited reactions, such as oxygenates reforming [27][28][29][30][31] and water-gas shift reaction [32][33][34][35]. 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.…”

Synthesis, structure and magnetic characterization of the first azido bridged heterotetranuclear chromium-sodium complex

“…The structure is composed of idealized octahedral [Cr III (N 5 O)] cores linked to the octahedral [Na(N 4 O 2 )] cores by two bridging azide ligands. Magnetic properties and EPR of 1 were also studied.Heteromultinuclear complexes have attracted a great attention in the field of coordination chemistry because of their applications for mimicking the active site of some metalloenzymes [1], preparing multifunctional catalysis [2] and are interesting materials for study on magnetic exchange when they include paramagnetic cores [3]. Mixed-metal aggregates, involving intimate association of Na + ions with transition-metal clusters [4], have recently drawn attention because of their interesting structural and magnetic properties and also because of their contribution towards the understanding of molecular recognition in biological systems [5].…”

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

“…This novel technology is normally called sorption-enhanced steam methane reforming (SESMR). Indeed, the concept of sorptionenhanced reaction process has recently also been applied to the steam reforming of ethanol and glycerol [11,12].…”