Sorption enhanced steam reforming of biodiesel by-product glycerol on Ni-CaO-MMT multifunctional catalysts

A series of multifunctional catalysts were derived from lamellar montmorillonite (MMT) via ultrasound assisted cation-exchange method. They were characterized by N-2 adsorption-desorption, X-ray diffraction (XRD), H-2 temperature-programmed reduction (H-2-TPR), H-2 pulse chemisorption, inductively coupled plasma optical emission spectrometry (ICP-OES), and transmission electron microscopy (TEM). The characterization results show that metal-support interaction (MSI) together with Ni and Ca dispersion interrelates with confinement effect of montmorillonite. The CO2 absorption capacity of CAT-5 (Ca/MMT molar ratio is 5) was still above 20.0% at the tenth cycle. The steam to glycerol molar ratio (S/G) and reaction temperature were investigated, and an S/G = 3 and a temperature of 600 degrees C were optimized. The hydrogen purity was significantly enhanced by the equilibrium shift of insitu CO2 removal at 600 degrees C. CAT-5 presents the best performance considering the synchronized absorption capacity and catalytic activity. Compared with CAT-M, CAT-5 shows higher stability in the multiple reactiondecarbonation cycles, which is due to the elevated sintering resistance of CaO derived from the confinement effect of lamellar structure. (C) 2016 Elsevier B.V. All rights reserved.