Hydrogen production from aqueous-phase reforming of polyols over Ru/ Al2O3 2 O 3 catalyst in a fixed-bed reactor

Aqueous-phase reforming (APR) is a promising method for hydrogen (H2) 2 ) production from renewable resources such as bio-oxygenates. In this study, H2 2 production from APR of three model compounds glycerol, sorbitol and xylitol was investigated. Glycerol and sorbitol are polyols commonly found in biomass and agricultural waste, while xylitol is a sugar alcohol commonly found in plant materials. The activity trials were performed in a continuous fixed-bed reactor using Ru/Al2O3 2 O 3 catalyst. This ruthenium catalyst was analysed using nitrogen adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The reaction parameters for APR trials were: temperature 453-498 K, pressure 1.2-2.4 MPa, feed concentration 5-15 wt % and weight hourly space velocity 0.15-0.6 1/h. The best process conditions were: T = 498 K, P = 2.4 MPa and feed concentration = 10 wt %. Glycerol exhibited the highest H2 2 yield (14.3 %) and H2 2 selectivity (65.1 %) when compared to sorbitol and xylitol at 498 K. In this way, this work provided useful information on the efficacy of Ru catalyst for the APR process.