Conversion of Glycerol to Hydrogen via a Steam Reforming Process over Nickel Catalysts

Abstract

A glut of inexpensive glycerol has resulted from expanding biodiesel production around the world. This glycerol could be used as a good renewable source to produce hydrogen fuel. Hydrogen production from glycerol via a steam reforming process over Ni/CeO 2, Ni/MgO, and Ni/TiO 2 catalysts was studied. The catalysts were characterized by using X-ray diffraction, thermogravimetric analysis, BET surface area analysis, metal dispersion, active surface area analysis, and hydrogen temperature programmed reduction. Ni/CeO 2 had the highest surface area (67.0 m 2 /g) followed by Ni/TiO 2 (64.9 m 2 /g) and Ni/MgO (50.2 m 2 /g). Also, Ni/CeO 2 showed the highest metal dispersion (6.14%) compared to Ni/MgO (0.38%) and Ni/TiO 2 (0.29%). Effects of reaction temperatures, feed flow rates (FFRs), and water/glycerol molar ratios (WGMRs) on hydrogen selectivity and glycerol conversion were analyzed. Ni/CeO 2 was found to be the best performing catalyst compared to Ni/MgO and Ni/TiO 2 under the experimental conditions investigated. Ni/CeO 2 gave the maximum hydrogen selectivity of 74.7% at a WGMR of 12:1, temperature of 600 °C, and FFR of 0.5 mL/min compared to Ni/MgO (38.6%) and Ni/TiO 2 (28.3%) under similar conditions.