Hydrogen production from glycerol dry reforming over Ag-promoted Ni/Al2O3

In recent times, glycerol has been employed as feedstock for the production of syngas (H-2 and CO) with H-2 as its main constituent. This study centers on dry reforming of glycerol over Ag-promoted Ni/Al2O3 catalysts. Prior to characterization, the catalysts were synthesized using the wet impregnation method. The reforming process was carried out using a fixed bed reactor at reactor operating conditions; 873-1173 K, carbon dioxide to glycerol ratio of 0.5 and gas hourly space velocity (WHSV) in the range of 14.4 <= 72 L gc(cat)(-1) h(-1)). Ag (3)-Ni/Al2O3 gave highest glycerol conversion and hydrogen yield of 40.7% and 32%, respectively. The optimum conditions which gave highest H-2 production, minimized methane production and carbon deposition were reaction temperature of 1073 K and carbon dioxide to glycerol ratio of 1:1. This result can attributed to the small metal crystallite size characteristics possessed by Ag (3) Ni/Al2O3, which enhanced metal dispersion in the catalyst matrix. Characterization of the spent catalyst revealed the formation of two types of carbon species; encapsulating and filamentous carbon which can be oxidized by O-2. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.